aboutsummaryrefslogtreecommitdiffstats
path: root/include/zot.php
blob: 38435a12435d00ee1f830445a87d6a9886e8fcc9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
<?php
/**
 * @file include/zot.php
 * @brief Hubzilla implementation of zot protocol.
 *
 * https://github.com/friendica/red/wiki/zot
 * https://github.com/friendica/red/wiki/Zot---A-High-Level-Overview
 *
 */

require_once('include/crypto.php');
require_once('include/items.php');
require_once('include/queue_fn.php');
require_once('include/perm_upgrade.php');
require_once('include/msglib.php');


/**
 * @brief Generates a unique string for use as a zot guid.
 *
 * Generates a unique string for use as a zot guid using our DNS-based url, the
 * channel nickname and some entropy.
 * The entropy ensures uniqueness against re-installs where the same URL and
 * nickname are chosen.
 *
 * @note zot doesn't require this to be unique. Internally we use a whirlpool
 * hash of this guid and the signature of this guid signed with the channel
 * private key. This can be verified and should make the probability of
 * collision of the verified result negligible within the constraints of our
 * immediate universe.
 *
 * @param string $channel_nick a unique nickname of controlling entity
 * @returns string
 */
function zot_new_uid($channel_nick) {
	$rawstr = z_root() . '/' . $channel_nick . '.' . mt_rand();
	return(base64url_encode(hash('whirlpool', $rawstr, true), true));
}

/**
 * @brief Generates a portable hash identifier for a channel.
 *
 * Generates a portable hash identifier for the channel identified by $guid and
 * signed with $guid_sig.
 *
 * @note This ID is portable across the network but MUST be calculated locally
 * by verifying the signature and can not be trusted as an identity.
 *
 * @param string $guid
 * @param string $guid_sig
 */
function make_xchan_hash($guid, $guid_sig) {
	return base64url_encode(hash('whirlpool', $guid . $guid_sig, true));
}

/**
 * @brief Given a zot hash, return all distinct hubs.
 *
 * This function is used in building the zot discovery packet and therefore
 * should only be used by channels which are defined on this hub.
 *
 * @param string $hash - xchan_hash
 * @returns array of hubloc (hub location structures)
 *  * \b hubloc_id          int
 *  * \b hubloc_guid        char(191)
 *  * \b hubloc_guid_sig    text
 *  * \b hubloc_hash        char(191)
 *  * \b hubloc_addr        char(191)
 *  * \b hubloc_flags       int
 *  * \b hubloc_status      int
 *  * \b hubloc_url         char(191)
 *  * \b hubloc_url_sig     text
 *  * \b hubloc_host        char(191)
 *  * \b hubloc_callback    char(191)
 *  * \b hubloc_connect     char(191)
 *  * \b hubloc_sitekey     text
 *  * \b hubloc_updated     datetime
 *  * \b hubloc_connected   datetime
 */
function zot_get_hublocs($hash) {

	/* Only search for active hublocs - e.g. those that haven't been marked deleted */

	$ret = q("select * from hubloc where hubloc_hash = '%s' and hubloc_deleted = 0 order by hubloc_url ",
		dbesc($hash)
	);

	return $ret;
}

/**
 * @brief Builds a zot notification packet.
 *
 * Builds a zot notification packet that you can either store in the queue with
 * a message array or call zot_zot to immediately zot it to the other side.
 *
 * @param array $channel
 *   sender channel structure
 * @param string $type
 *   packet type: one of 'ping', 'pickup', 'purge', 'refresh', 'keychange', 'force_refresh', 'notify', 'auth_check'
 * @param array $recipients
 *   envelope information, array ( 'guid' => string, 'guid_sig' => string ); empty for public posts
 * @param string $remote_key
 *   optional public site key of target hub used to encrypt entire packet
 *   NOTE: remote_key and encrypted packets are required for 'auth_check' packets, optional for all others
 * @param string $methods
 *   optional comma separated list of encryption methods @ref zot_best_algorithm()
 * @param string $secret
 *   random string, required for packets which require verification/callback
 *   e.g. 'pickup', 'purge', 'notify', 'auth_check'. Packet types 'ping', 'force_refresh', and 'refresh' do not require verification
 * @param string $extra
 * @returns string json encoded zot packet
 */
function zot_build_packet($channel, $type = 'notify', $recipients = null, $remote_key = null, $methods = '', $secret = null, $extra = null) {

	$sig_method = get_config('system','signature_algorithm','sha256');

	$data = [
		'type' => $type,
		'sender' => [
			'guid' => $channel['channel_guid'],
			'guid_sig' => base64url_encode(rsa_sign($channel['channel_guid'],$channel['channel_prvkey'],$sig_method)),
			'url' => z_root(),
			'url_sig' => base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey'],$sig_method)),
			'sitekey' => get_config('system','pubkey')
		],
		'callback' => '/post',
		'version' => Zotlabs\Lib\System::get_zot_revision(),
		'encryption' => crypto_methods(),
		'signing' => signing_methods()
	];

	if ($recipients) {
		for ($x = 0; $x < count($recipients); $x ++)
			unset($recipients[$x]['hash']);

		$data['recipients'] = $recipients;
	}

	if ($secret) {
		$data['secret'] = preg_replace('/[^0-9a-fA-F]/','',$secret);
		$data['secret_sig'] = base64url_encode(rsa_sign($secret,$channel['channel_prvkey'],$sig_method));
	}

	if ($extra) {
		foreach ($extra as $k => $v)
			$data[$k] = $v;
	}

	logger('zot_build_packet: ' . print_r($data,true), LOGGER_DATA, LOG_DEBUG);

	// Hush-hush ultra top-secret mode

	if($remote_key) {
		$algorithm = zot_best_algorithm($methods);
		$data = crypto_encapsulate(json_encode($data),$remote_key, $algorithm);
	}

	return json_encode($data);
}


/**
 * @brief Builds a zot6 notification packet.
 *
 * Builds a zot6 notification packet that you can either store in the queue with
 * a message array or call zot_zot to immediately zot it to the other side.
 *
 * @param array $channel
 *   sender channel structure
 * @param string $type
 *   packet type: one of 'ping', 'pickup', 'purge', 'refresh', 'keychange', 'force_refresh', 'notify', 'auth_check'
 * @param array $recipients
 *   envelope information, array ( 'guid' => string, 'guid_sig' => string ); empty for public posts
 * @param string msg
 *   optional message
 * @param string $remote_key
 *   optional public site key of target hub used to encrypt entire packet
 *   NOTE: remote_key and encrypted packets are required for 'auth_check' packets, optional for all others
 * @param string $methods
 *   optional comma separated list of encryption methods @ref zot_best_algorithm()
 * @param string $secret
 *   random string, required for packets which require verification/callback
 *   e.g. 'pickup', 'purge', 'notify', 'auth_check'. Packet types 'ping', 'force_refresh', and 'refresh' do not require verification
 * @param string $extra
 * @returns string json encoded zot packet
 */
function zot6_build_packet($channel, $type = 'notify', $recipients = null, $msg = '', $remote_key = null, $methods = '', $secret = null, $extra = null) {

	$sig_method = get_config('system','signature_algorithm','sha256');

	$data = [
		'type' => $type,
		'sender' => [
			'guid' => $channel['channel_guid'],
			'guid_sig' => base64url_encode(rsa_sign($channel['channel_guid'],$channel['channel_prvkey'],$sig_method)),
			'url' => z_root(),
			'url_sig' => base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey'],$sig_method)),
			'sitekey' => get_config('system','pubkey')
		],
		'callback' => '/post',
		'version' => Zotlabs\Lib\System::get_zot_revision(),
		'encryption' => crypto_methods(),
		'signing' => signing_methods()
	];

	if ($recipients) {
		for ($x = 0; $x < count($recipients); $x ++)
			unset($recipients[$x]['hash']);

		$data['recipients'] = $recipients;
	}

	if($msg) {
		$data['msg'] = $msg;
	}

	if ($secret) {
		$data['secret'] = preg_replace('/[^0-9a-fA-F]/','',$secret);
		$data['secret_sig'] = base64url_encode(rsa_sign($secret,$channel['channel_prvkey'],$sig_method));
	}

	if ($extra) {
		foreach ($extra as $k => $v)
			$data[$k] = $v;
	}

	logger('zot6_build_packet: ' . print_r($data,true), LOGGER_DATA, LOG_DEBUG);

	// Hush-hush ultra top-secret mode

	if($remote_key) {
		$algorithm = zot_best_algorithm($methods);
		$data = crypto_encapsulate(json_encode($data),$remote_key, $algorithm);
	}

	return json_encode($data);
}




/**
 * @brief Choose best encryption function from those available on both sites.
 *
 * @param string $methods
 *   comma separated list of encryption methods
 * @return string first match from our site method preferences crypto_methods() array
 * of a method which is common to both sites; or 'aes256cbc' if no matches are found.
 */
function zot_best_algorithm($methods) {

	$x = [
			'methods' => $methods,
			'result' => ''
	];
	/**
	 * @hooks zot_best_algorithm
	 *   Called when negotiating crypto algorithms with remote sites.
	 *   * \e string \b methods - comma separated list of encryption methods
	 *   * \e string \b result - the algorithm to return
	 */
	call_hooks('zot_best_algorithm', $x);

	if($x['result'])
		return $x['result'];

	if($methods) {
		$x = explode(',', $methods);
		if($x) {
			$y = crypto_methods();
			if($y) {
				foreach($y as $yv) {
					$yv = trim($yv);
					if(in_array($yv, $x)) {
						return($yv);
					}
				}
			}
		}
	}

	return 'aes256cbc';
}


/**
 * @brief
 *
 * @see z_post_url()
 *
 * @param string $url
 * @param array $data
 * @param array $channel (optional if using zot6 delivery)
 * @param array $crypto (optional if encrypted httpsig, requires hubloc_sitekey and site_crypto elements)
 * @return array see z_post_url() for returned data format
 */
function zot_zot($url, $data, $channel = null,$crypto = null) {

	$headers = [];

	if($channel) {
		$headers['X-Zot-Token'] = random_string();
		$hash = \Zotlabs\Web\HTTPSig::generate_digest($data,false);
		$headers['X-Zot-Digest'] = 'SHA-256=' . $hash;
		$h = \Zotlabs\Web\HTTPSig::create_sig('',$headers,$channel['channel_prvkey'],'acct:' . $channel['channel_address'] . '@' . \App::get_hostname(),false,false,'sha512',(($crypto) ? $crypto['hubloc_sitekey'] : ''), (($crypto) ? zot_best_algorithm($crypto['site_crypto']) : ''));
	}

	$redirects = 0;
	return z_post_url($url, array('data' => $data),$redirects,((empty($h)) ? [] : [ 'headers' => $h ]));
}

/**
 * @brief Refreshes after permission changed or friending, etc.
 *
 * The top half of this function is similar to \\Zotlabs\\Zot\\Finger::run() and could potentially be
 * consolidated.
 *
 * zot_refresh is typically invoked when somebody has changed permissions of a channel and they are notified
 * to fetch new permissions via a finger/discovery operation. This may result in a new connection
 * (abook entry) being added to a local channel and it may result in auto-permissions being granted.
 *
 * Friending in zot is accomplished by sending a refresh packet to a specific channel which indicates a
 * permission change has been made by the sender which affects the target channel. The hub controlling
 * the target channel does targetted discovery (a zot-finger request requesting permissions for the local
 * channel). These are decoded here, and if necessary and abook structure (addressbook) is created to store
 * the permissions assigned to this channel.
 *
 * Initially these abook structures are created with a 'pending' flag, so that no reverse permissions are
 * implied until this is approved by the owner channel. A channel can also auto-populate permissions in
 * return and send back a refresh packet of its own. This is used by forum and group communication channels
 * so that friending and membership in the channel's "club" is automatic.
 *
 * @param array $them => xchan structure of sender
 * @param array $channel => local channel structure of target recipient, required for "friending" operations
 * @param array $force (optional) default false
 *
 * @return boolean
 *   * \b true if successful
 *   * otherwise \b false
 */
function zot_refresh($them, $channel = null, $force = false) {

	if (array_key_exists('xchan_network', $them) && ($them['xchan_network'] !== 'zot')) {
		logger('not got zot. ' . $them['xchan_name']);
		return true;
	}

	logger('them: ' . print_r($them,true), LOGGER_DATA, LOG_DEBUG);
	if ($channel)
		logger('channel: ' . print_r($channel,true), LOGGER_DATA, LOG_DEBUG);

	$url = null;

	if ($them['hubloc_url']) {
		$url = $them['hubloc_url'];
	}
	else {
		$r = null;

		// if they re-installed the server we could end up with the wrong record - pointing to the old install.
		// We'll order by reverse id to try and pick off the newest one first and hopefully end up with the
		// correct hubloc. If this doesn't work we may have to re-write this section to try them all.

		if(array_key_exists('xchan_addr',$them) && $them['xchan_addr']) {
			$r = q("select hubloc_url, hubloc_primary from hubloc where hubloc_addr = '%s' order by hubloc_id desc",
				dbesc($them['xchan_addr'])
			);
		}
		if(! $r) {
			$r = q("select hubloc_url, hubloc_primary from hubloc where hubloc_hash = '%s' order by hubloc_id desc",
				dbesc($them['xchan_hash'])
			);
		}

		if ($r) {
			foreach ($r as $rr) {
				if (intval($rr['hubloc_primary'])) {
					$url = $rr['hubloc_url'];
					break;
				}
			}
			if (! $url)
				$url = $r[0]['hubloc_url'];
		}
	}
	if (! $url) {
		logger('zot_refresh: no url');
		return false;
	}

	$s = q("select site_dead from site where site_url = '%s' limit 1",
		dbesc($url)
	);

	if($s && intval($s[0]['site_dead']) && (! $force)) {
		logger('zot_refresh: site ' . $url . ' is marked dead and force flag is not set. Cancelling operation.');
		return false;
	}


	$token = random_string();

	$postvars = [];

	$postvars['token'] = $token;

	if($channel) {
		$postvars['target']     = $channel['channel_guid'];
		$postvars['target_sig'] = $channel['channel_guid_sig'];
		$postvars['key']        = $channel['channel_pubkey'];
	}

	if (array_key_exists('xchan_addr',$them) && $them['xchan_addr'])
		$postvars['address'] = $them['xchan_addr'];
	if (array_key_exists('xchan_hash',$them) && $them['xchan_hash'])
		$postvars['guid_hash'] = $them['xchan_hash'];
	if (array_key_exists('xchan_guid',$them) && $them['xchan_guid']
		&& array_key_exists('xchan_guid_sig',$them) && $them['xchan_guid_sig']) {
		$postvars['guid'] = $them['xchan_guid'];
		$postvars['guid_sig'] = $them['xchan_guid_sig'];
	}

	$rhs = '/.well-known/zot-info';

	logger('zot_refresh: ' . $url, LOGGER_DATA, LOG_INFO);


	$result = z_post_url($url . $rhs,$postvars);

	if ($result['success']) {

		$j = json_decode($result['body'],true);

		if (! (($j) && ($j['success']))) {
			logger('Result not decodable');
			return false;
		}

		logger('zot-info: ' . print_r($result,true), LOGGER_DATA, LOG_DEBUG);

		$signed_token = ((is_array($j) && array_key_exists('signed_token',$j)) ? $j['signed_token'] : null);
		if($signed_token) {
			$valid = rsa_verify('token.' . $token,base64url_decode($signed_token),$j['key']);
			if(! $valid) {
				logger('invalid signed token: ' . $url . $rhs, LOGGER_NORMAL, LOG_ERR);
				return false;
			}
		}
		else {
			logger('No signed token from '  . $url . $rhs, LOGGER_NORMAL, LOG_WARNING);
			return false;
		}

		$x = import_xchan($j, (($force) ? UPDATE_FLAGS_FORCED : UPDATE_FLAGS_UPDATED));

		if(! $x['success'])
			return false;

		if($channel) {
			if($j['permissions']['data']) {
				$permissions = crypto_unencapsulate(
					[
					'data' => $j['permissions']['data'],
					'key'  => $j['permissions']['key'],
					'iv'   => $j['permissions']['iv'],
					'alg'  => $j['permissions']['alg']
					],
					$channel['channel_prvkey']);
				if($permissions)
					$permissions = json_decode($permissions,true);
				logger('decrypted permissions: ' . print_r($permissions,true), LOGGER_DATA, LOG_DEBUG);
			}
			else
				$permissions = $j['permissions'];

			if($permissions && is_array($permissions)) {
				$old_read_stream_perm = get_abconfig($channel['channel_id'],$x['hash'],'their_perms','view_stream');

				foreach($permissions as $k => $v) {
					set_abconfig($channel['channel_id'],$x['hash'],'their_perms',$k,$v);
				}
			}

			if(array_key_exists('profile',$j) && array_key_exists('next_birthday',$j['profile'])) {
				$next_birthday = datetime_convert('UTC','UTC',$j['profile']['next_birthday']);
			}
			else {
				$next_birthday = NULL_DATE;
			}

			$profile_assign = get_pconfig($channel['channel_id'],'system','profile_assign','');

			// Keep original perms to check if we need to notify them
			$previous_perms = get_all_perms($channel['channel_id'],$x['hash'],false);

			$r = q("select * from abook where abook_xchan = '%s' and abook_channel = %d and abook_self = 0 limit 1",
				dbesc($x['hash']),
				intval($channel['channel_id'])
			);

			if($r) {

				// connection exists

				// if the dob is the same as what we have stored (disregarding the year), keep the one
				// we have as we may have updated the year after sending a notification; and resetting
				// to the one we just received would cause us to create duplicated events.

				if(substr($r[0]['abook_dob'],5) == substr($next_birthday,5))
					$next_birthday = $r[0]['abook_dob'];

				$y = q("update abook set abook_dob = '%s'
					where abook_xchan = '%s' and abook_channel = %d
					and abook_self = 0 ",
					dbescdate($next_birthday),
					dbesc($x['hash']),
					intval($channel['channel_id'])
				);

				if(! $y)
					logger('abook update failed');
				else {
					// if we were just granted read stream permission and didn't have it before, try to pull in some posts
					if((! $old_read_stream_perm) && (intval($permissions['view_stream'])))
						Zotlabs\Daemon\Master::Summon(array('Onepoll',$r[0]['abook_id']));
				}
			}
			else {

				$p = \Zotlabs\Access\Permissions::connect_perms($channel['channel_id']);

				$my_perms  = $p['perms'];
				$automatic = $p['automatic'];

				// new connection

				if($my_perms) {
					foreach($my_perms as $k => $v) {
						set_abconfig($channel['channel_id'],$x['hash'],'my_perms',$k,$v);
					}
				}

				$closeness = get_pconfig($channel['channel_id'],'system','new_abook_closeness');
				if($closeness === false)
					$closeness = 80;

				$y = abook_store_lowlevel(
					[
						'abook_account'   => intval($channel['channel_account_id']),
						'abook_channel'   => intval($channel['channel_id']),
						'abook_closeness' => intval($closeness),
						'abook_xchan'     => $x['hash'],
						'abook_profile'   => $profile_assign,
						'abook_created'   => datetime_convert(),
						'abook_updated'   => datetime_convert(),
						'abook_dob'       => $next_birthday,
						'abook_pending'   => intval(($automatic) ? 0 : 1)
					]
				);

				if($y) {
					logger("New introduction received for {$channel['channel_name']}");
					$new_perms = get_all_perms($channel['channel_id'],$x['hash'],false);

					// Send a clone sync packet and a permissions update if permissions have changed

					$new_connection = q("select * from abook left join xchan on abook_xchan = xchan_hash where abook_xchan = '%s' and abook_channel = %d and abook_self = 0 order by abook_created desc limit 1",
						dbesc($x['hash']),
						intval($channel['channel_id'])
					);

					if($new_connection) {
						if(! \Zotlabs\Access\Permissions::PermsCompare($new_perms,$previous_perms))
							Zotlabs\Daemon\Master::Summon(array('Notifier','permission_create',$new_connection[0]['abook_id']));
						Zotlabs\Lib\Enotify::submit(
							[
							'type'       => NOTIFY_INTRO,
							'from_xchan' => $x['hash'],
							'to_xchan'   => $channel['channel_hash'],
							'link'       => z_root() . '/connedit/' . $new_connection[0]['abook_id']
							]
						);

						if(intval($permissions['view_stream'])) {
							if(intval(get_pconfig($channel['channel_id'],'perm_limits','send_stream') & PERMS_PENDING)
								|| (! intval($new_connection[0]['abook_pending'])))
								Zotlabs\Daemon\Master::Summon(array('Onepoll',$new_connection[0]['abook_id']));
						}


						// If there is a default group for this channel, add this connection to it
						// for pending connections this will happens at acceptance time.

						if(! intval($new_connection[0]['abook_pending'])) {
							$default_group = $channel['channel_default_group'];
							if($default_group) {
								require_once('include/group.php');
								$g = group_rec_byhash($channel['channel_id'],$default_group);
								if($g)
									group_add_member($channel['channel_id'],'',$x['hash'],$g['id']);
							}
						}

						unset($new_connection[0]['abook_id']);
						unset($new_connection[0]['abook_account']);
						unset($new_connection[0]['abook_channel']);

						$abconfig = load_abconfig($channel['channel_id'],$new_connection['abook_xchan']);
						if($abconfig)
							$new_connection['abconfig'] = $abconfig;

						build_sync_packet($channel['channel_id'], array('abook' => $new_connection));
					}
				}
			}
		}
		return true;
	}

	return false;
}

/**
 * @brief Look up if channel is known and previously verified.
 *
 * A guid and a url, both signed by the sender, distinguish a known sender at a
 * known location.
 * This function looks these up to see if the channel is known and therefore
 * previously verified. If not, we will need to verify it.
 *
 * @param array $arr an associative array which must contain:
 *  * \e string \b guid => guid of conversant
 *  * \e string \b guid_sig => guid signed with conversant's private key
 *  * \e string \b url => URL of the origination hub of this communication
 *  * \e string \b url_sig => URL signed with conversant's private key
 * @param boolean $multiple (optional) default false
 *
 * @return array|null
 *   * null if site is blacklisted or not found
 *   * otherwise an array with an hubloc record
 */
function zot_gethub($arr, $multiple = false) {

	if($arr['guid'] && $arr['guid_sig'] && $arr['url'] && $arr['url_sig']) {

		if(! check_siteallowed($arr['url'])) {
			logger('blacklisted site: ' . $arr['url']);
			return null;
		}

		$limit = (($multiple) ? '' : ' limit 1 ');
		$sitekey = ((array_key_exists('sitekey',$arr) && $arr['sitekey']) ? " and hubloc_sitekey = '" . dbesc(protect_sprintf($arr['sitekey'])) . "' " : '');

		$r = q("select hubloc.*, site.site_crypto from hubloc left join site on hubloc_url = site_url
				where hubloc_guid = '%s' and hubloc_guid_sig = '%s'
				and hubloc_url = '%s' and hubloc_url_sig = '%s'
				$sitekey $limit",
			dbesc($arr['guid']),
			dbesc($arr['guid_sig']),
			dbesc($arr['url']),
			dbesc($arr['url_sig'])
		);
		if($r) {
			logger('Found', LOGGER_DEBUG);
			return (($multiple) ? $r : $r[0]);
		}
	}
	logger('Not found: ' . print_r($arr,true), LOGGER_DEBUG);

	return false;
}

/**
 * @brief Registers an unknown hub.
 *
 * A communication has been received which has an unknown (to us) sender.
 * Perform discovery based on our calculated hash of the sender at the
 * origination address. This will fetch the discovery packet of the sender,
 * which contains the public key we need to verify our guid and url signatures.
 *
 * @param array $arr an associative array which must contain:
 *  * \e string \b guid => guid of conversant
 *  * \e string \b guid_sig => guid signed with conversant's private key
 *  * \e string \b url => URL of the origination hub of this communication
 *  * \e string \b url_sig => URL signed with conversant's private key
 *
 * @return array An associative array with
 *  * \b success boolean true or false
 *  * \b message (optional) error string only if success is false
 */
function zot_register_hub($arr) {

	$result = [ 'success' => false ];

	if($arr['url'] && $arr['url_sig'] && $arr['guid'] && $arr['guid_sig']) {

		$sig_methods = ((array_key_exists('signing',$arr) && is_array($arr['signing'])) ? $arr['signing'] : [ 'sha256' ]);

		$guid_hash = make_xchan_hash($arr['guid'],$arr['guid_sig']);

		$url = $arr['url'] . '/.well-known/zot-info/?f=&guid_hash=' . $guid_hash;

		logger('zot_register_hub: ' . $url, LOGGER_DEBUG);

		$x = z_fetch_url($url);

		logger('zot_register_hub: ' . print_r($x,true), LOGGER_DATA, LOG_DEBUG);

		if($x['success']) {
			$record = json_decode($x['body'],true);

			/*
			 * We now have a key - only continue registration if our signatures are valid
			 * AND the guid and guid sig in the returned packet match those provided in
			 * our current communication.
			 */

			foreach($sig_methods as $method) {
				if((rsa_verify($arr['guid'],base64url_decode($arr['guid_sig']),$record['key'],$method))
				&& (rsa_verify($arr['url'],base64url_decode($arr['url_sig']),$record['key'],$method))
				&& ($arr['guid'] === $record['guid'])
				&& ($arr['guid_sig'] === $record['guid_sig'])) {
					$c = import_xchan($record);
					if($c['success'])
						$result['success'] = true;
				}
				else {
					logger('Failure to verify returned packet using ' . $method);
				}
			}
		}
	}

	return $result;
}

/**
 * @brief Takes an associative array of a fetched discovery packet and updates
 *   all internal data structures which need to be updated as a result.
 *
 * @param array $arr => json_decoded discovery packet
 * @param int $ud_flags
 *    Determines whether to create a directory update record if any changes occur, default is UPDATE_FLAGS_UPDATED
 *    $ud_flags = UPDATE_FLAGS_FORCED indicates a forced refresh where we unconditionally create a directory update record
 *      this typically occurs once a month for each channel as part of a scheduled ping to notify the directory
 *      that the channel still exists
 * @param array $ud_arr
 *    If set [typically by update_directory_entry()] indicates a specific update table row and more particularly
 *    contains a particular address (ud_addr) which needs to be updated in that table.
 *
 * @return array An associative array with:
 *   * \e boolean \b success boolean true or false
 *   * \e string \b message (optional) error string only if success is false
 */
function import_xchan($arr, $ud_flags = UPDATE_FLAGS_UPDATED, $ud_arr = null) {

	/**
	 * @hooks import_xchan
	 *   Called when processing the result of zot_finger() to store the result
	 *   * \e array
	 */
	call_hooks('import_xchan', $arr);

	$ret = array('success' => false);
	$dirmode = intval(get_config('system','directory_mode'));

	$changed = false;
	$what = '';

	if(! (is_array($arr) && array_key_exists('success',$arr) && $arr['success'])) {
		logger('Invalid data packet: ' . print_r($arr,true));
		$ret['message'] = t('Invalid data packet');
		return $ret;
	}

	if(! ($arr['guid'] && $arr['guid_sig'])) {
		logger('No identity information provided. ' . print_r($arr,true));
		return $ret;
	}

	$xchan_hash = make_xchan_hash($arr['guid'],$arr['guid_sig']);
	$arr['hash'] = $xchan_hash;

	$import_photos = false;

	$sig_methods = ((array_key_exists('signing',$arr) && is_array($arr['signing'])) ? $arr['signing'] : [ 'sha256' ]);
	$verified = false;

	foreach($sig_methods as $method) {
		if(! rsa_verify($arr['guid'],base64url_decode($arr['guid_sig']),$arr['key'],$method)) {
			logger('Unable to verify channel signature for ' . $arr['address'] . ' using ' . $method);
			continue;
		}
		else {
			$verified = true;
		}
	}
	if(! $verified) {
		$ret['message'] = t('Unable to verify channel signature');
		return $ret;
	}

	logger('import_xchan: ' . $xchan_hash, LOGGER_DEBUG);

	$r = q("select * from xchan where xchan_hash = '%s' limit 1",
		dbesc($xchan_hash)
	);

	if(! array_key_exists('connect_url', $arr))
		$arr['connect_url'] = '';

	if(strpos($arr['address'],'/') !== false)
		$arr['address'] = substr($arr['address'],0,strpos($arr['address'],'/'));

	if($r) {
		if($r[0]['xchan_photo_date'] != $arr['photo_updated'])
			$import_photos = true;

		// if we import an entry from a site that's not ours and either or both of us is off the grid - hide the entry.
		/** @TODO: check if we're the same directory realm, which would mean we are allowed to see it */

		$dirmode = get_config('system','directory_mode');

		if((($arr['site']['directory_mode'] === 'standalone') || ($dirmode & DIRECTORY_MODE_STANDALONE)) && ($arr['site']['url'] != z_root()))
			$arr['searchable'] = false;

		$hidden = (1 - intval($arr['searchable']));

		$hidden_changed = $adult_changed = $deleted_changed = $pubforum_changed = 0;

		if(intval($r[0]['xchan_hidden']) != (1 - intval($arr['searchable'])))
			$hidden_changed = 1;
		if(intval($r[0]['xchan_selfcensored']) != intval($arr['adult_content']))
			$adult_changed = 1;
		if(intval($r[0]['xchan_deleted']) != intval($arr['deleted']))
			$deleted_changed = 1;
		if(intval($r[0]['xchan_pubforum']) != intval($arr['public_forum']))
			$pubforum_changed = 1;

		if($arr['protocols']) {
			$protocols = implode(',',$arr['protocols']);
			if($protocols !== 'zot') {
				set_xconfig($xchan_hash,'system','protocols',$protocols);
			}
			else {
				del_xconfig($xchan_hash,'system','protocols');
			}
		}

		if(($r[0]['xchan_name_date'] != $arr['name_updated'])
			|| ($r[0]['xchan_connurl'] != $arr['connections_url'])
			|| ($r[0]['xchan_addr'] != $arr['address'])
			|| ($r[0]['xchan_follow'] != $arr['follow_url'])
			|| ($r[0]['xchan_connpage'] != $arr['connect_url'])
			|| ($r[0]['xchan_url'] != $arr['url'])
			|| $hidden_changed || $adult_changed || $deleted_changed || $pubforum_changed ) {
			$rup = q("update xchan set xchan_name = '%s', xchan_name_date = '%s', xchan_connurl = '%s', xchan_follow = '%s',
				xchan_connpage = '%s', xchan_hidden = %d, xchan_selfcensored = %d, xchan_deleted = %d, xchan_pubforum = %d,
				xchan_addr = '%s', xchan_url = '%s' where xchan_hash = '%s'",
				dbesc(($arr['name']) ? $arr['name'] : '-'),
				dbesc($arr['name_updated']),
				dbesc($arr['connections_url']),
				dbesc($arr['follow_url']),
				dbesc($arr['connect_url']),
				intval(1 - intval($arr['searchable'])),
				intval($arr['adult_content']),
				intval($arr['deleted']),
				intval($arr['public_forum']),
				dbesc($arr['address']),
				dbesc($arr['url']),
				dbesc($xchan_hash)
			);

			logger('Update: existing: ' . print_r($r[0],true), LOGGER_DATA, LOG_DEBUG);
			logger('Update: new: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
			$what .= 'xchan ';
			$changed = true;
		}
	}
	else {
		$import_photos = true;

		if((($arr['site']['directory_mode'] === 'standalone')
				|| ($dirmode & DIRECTORY_MODE_STANDALONE))
				&& ($arr['site']['url'] != z_root()))
			$arr['searchable'] = false;

		$x = xchan_store_lowlevel(
			[
				'xchan_hash'           => $xchan_hash,
				'xchan_guid'           => $arr['guid'],
				'xchan_guid_sig'       => $arr['guid_sig'],
				'xchan_pubkey'         => $arr['key'],
				'xchan_photo_mimetype' => $arr['photo_mimetype'],
				'xchan_photo_l'        => $arr['photo'],
				'xchan_addr'           => $arr['address'],
				'xchan_url'            => $arr['url'],
				'xchan_connurl'        => $arr['connections_url'],
				'xchan_follow'         => $arr['follow_url'],
				'xchan_connpage'       => $arr['connect_url'],
				'xchan_name'           => (($arr['name']) ? $arr['name'] : '-'),
				'xchan_network'        => 'zot',
				'xchan_photo_date'     => $arr['photo_updated'],
				'xchan_name_date'      => $arr['name_updated'],
				'xchan_hidden'         => intval(1 - intval($arr['searchable'])),
				'xchan_selfcensored'   => $arr['adult_content'],
				'xchan_deleted'        => $arr['deleted'],
				'xchan_pubforum'       => $arr['public_forum']
			]
		);

		$what .= 'new_xchan';
		$changed = true;
	}

	if($import_photos) {

		require_once('include/photo/photo_driver.php');

		// see if this is a channel clone that's hosted locally - which we treat different from other xchans/connections

		$local = q("select channel_account_id, channel_id from channel where channel_hash = '%s' limit 1",
			dbesc($xchan_hash)
		);
		if($local) {
			$ph = z_fetch_url($arr['photo'], true);
			if($ph['success']) {

				$hash = import_channel_photo($ph['body'], $arr['photo_mimetype'], $local[0]['channel_account_id'], $local[0]['channel_id']);

				if($hash) {
					// unless proven otherwise
					$is_default_profile = 1;

					$profile = q("select is_default from profile where aid = %d and uid = %d limit 1",
						intval($local[0]['channel_account_id']),
						intval($local[0]['channel_id'])
					);
					if($profile) {
						if(! intval($profile[0]['is_default']))
							$is_default_profile = 0;
					}

					// If setting for the default profile, unset the profile photo flag from any other photos I own
					if($is_default_profile) {
						q("UPDATE photo SET photo_usage = %d WHERE photo_usage = %d AND resource_id != '%s' AND aid = %d AND uid = %d",
							intval(PHOTO_NORMAL),
							intval(PHOTO_PROFILE),
							dbesc($hash),
							intval($local[0]['channel_account_id']),
							intval($local[0]['channel_id'])
						);
					}
				}

				// reset the names in case they got messed up when we had a bug in this function
				$photos = array(
					z_root() . '/photo/profile/l/' . $local[0]['channel_id'],
					z_root() . '/photo/profile/m/' . $local[0]['channel_id'],
					z_root() . '/photo/profile/s/' . $local[0]['channel_id'],
					$arr['photo_mimetype'],
					false
				);
			}
		}
		else {
			$photos = import_xchan_photo($arr['photo'], $xchan_hash);
		}
		if($photos) {
			if($photos[4]) {
				// importing the photo failed somehow. Leave the photo_date alone so we can try again at a later date.
				// This often happens when somebody joins the matrix with a bad cert.
				$r = q("update xchan set xchan_photo_l = '%s', xchan_photo_m = '%s', xchan_photo_s = '%s', xchan_photo_mimetype = '%s'
					where xchan_hash = '%s'",
					dbesc($photos[0]),
					dbesc($photos[1]),
					dbesc($photos[2]),
					dbesc($photos[3]),
					dbesc($xchan_hash)
				);
			}
			else {
				$r = q("update xchan set xchan_photo_date = '%s', xchan_photo_l = '%s', xchan_photo_m = '%s', xchan_photo_s = '%s', xchan_photo_mimetype = '%s'
					where xchan_hash = '%s'",
					dbescdate(datetime_convert('UTC','UTC',$arr['photo_updated'])),
					dbesc($photos[0]),
					dbesc($photos[1]),
					dbesc($photos[2]),
					dbesc($photos[3]),
					dbesc($xchan_hash)
				);
			}
			$what .= 'photo ';
			$changed = true;
		}
	}

	// what we are missing for true hub independence is for any changes in the primary hub to
	// get reflected not only in the hublocs, but also to update the URLs and addr in the appropriate xchan

	$s = sync_locations($arr, $arr);

	if($s) {
		if($s['change_message'])
			$what .= $s['change_message'];
		if($s['changed'])
			$changed = $s['changed'];
		if($s['message'])
			$ret['message'] .= $s['message'];
	}

	// Which entries in the update table are we interested in updating?

	$address = (($ud_arr && $ud_arr['ud_addr']) ? $ud_arr['ud_addr'] : $arr['address']);


	// Are we a directory server of some kind?

	$other_realm = false;
	$realm = get_directory_realm();
	if(array_key_exists('site',$arr)
		&& array_key_exists('realm',$arr['site'])
		&& (strpos($arr['site']['realm'],$realm) === false))
		$other_realm = true;

	if($dirmode != DIRECTORY_MODE_NORMAL) {

		// We're some kind of directory server. However we can only add directory information
		// if the entry is in the same realm (or is a sub-realm). Sub-realms are denoted by
		// including the parent realm in the name. e.g. 'RED_GLOBAL:foo' would allow an entry to
		// be in directories for the local realm (foo) and also the RED_GLOBAL realm.

		if(array_key_exists('profile',$arr) && is_array($arr['profile']) && (! $other_realm)) {
			$profile_changed = import_directory_profile($xchan_hash,$arr['profile'],$address,$ud_flags, 1);
			if($profile_changed) {
				$what .= 'profile ';
				$changed = true;
			}
		}
		else {
			logger('Profile not available - hiding');
			// they may have made it private
			$r = q("delete from xprof where xprof_hash = '%s'",
				dbesc($xchan_hash)
			);
			$r = q("delete from xtag where xtag_hash = '%s' and xtag_flags = 0",
				dbesc($xchan_hash)
			);
		}
	}

	if(array_key_exists('site',$arr) && is_array($arr['site'])) {
		$profile_changed = import_site($arr['site'],$arr['key']);
		if($profile_changed) {
			$what .= 'site ';
			$changed = true;
		}
	}

	if(($changed) || ($ud_flags == UPDATE_FLAGS_FORCED)) {
		$guid = random_string() . '@' . App::get_hostname();
		update_modtime($xchan_hash,$guid,$address,$ud_flags);
		logger('Changed: ' . $what,LOGGER_DEBUG);
	}
	elseif(! $ud_flags) {
		// nothing changed but we still need to update the updates record
		q("update updates set ud_flags = ( ud_flags | %d ) where ud_addr = '%s' and not (ud_flags & %d) > 0 ",
			intval(UPDATE_FLAGS_UPDATED),
			dbesc($address),
			intval(UPDATE_FLAGS_UPDATED)
		);
	}

	if(! x($ret,'message')) {
		$ret['success'] = true;
		$ret['hash'] = $xchan_hash;
	}

	logger('Result: ' . print_r($ret,true), LOGGER_DATA, LOG_DEBUG);
	return $ret;
}

/**
 * @brief Called immediately after sending a zot message which is using queue processing.
 *
 * Updates the queue item according to the response result and logs any information
 * returned to aid communications troubleshooting.
 *
 * @param string $hub - url of site we just contacted
 * @param array $arr - output of z_post_url()
 * @param array $outq - The queue structure attached to this request
 */
function zot_process_response($hub, $arr, $outq) {

	if(! $arr['success']) {
		logger('Failed: ' . $hub);
		return;
	}

	$x = json_decode($arr['body'], true);

	if(! $x) {
		logger('No json from ' . $hub);
		logger('Headers: ' . print_r($arr['header'], true), LOGGER_DATA, LOG_DEBUG);
	}

	if(is_array($x) && array_key_exists('delivery_report',$x) && is_array($x['delivery_report'])) {

		if(array_key_exists('iv',$x['delivery_report'])) {
			$j = crypto_unencapsulate($x['delivery_report'],get_config('system','prvkey'));
			if($j) {
				$x['delivery_report'] = json_decode($j,true);
			}
			if(! (is_array($x['delivery_report']) && count($x['delivery_report']))) {
				logger('encrypted delivery report could not be decrypted');
				return;
			}
		}

		foreach($x['delivery_report'] as $xx) {
                        call_hooks('dreport_process',$xx);
			if(is_array($xx) && array_key_exists('message_id',$xx) && delivery_report_is_storable($xx)) {
				q("insert into dreport ( dreport_mid, dreport_site, dreport_recip, dreport_result, dreport_time, dreport_xchan ) values ( '%s', '%s','%s','%s','%s','%s' ) ",
					dbesc($xx['message_id']),
					dbesc($xx['location']),
					dbesc($xx['recipient']),
					dbesc($xx['status']),
					dbesc(datetime_convert($xx['date'])),
					dbesc($xx['sender'])
				);
			}
		}
	}

	// we have a more descriptive delivery report, so discard the per hub 'queued' report.

	q("delete from dreport where dreport_queue = '%s' ",
		dbesc($outq['outq_hash'])
	);

	// update the timestamp for this site

	q("update site set site_dead = 0, site_update = '%s' where site_url = '%s'",
		dbesc(datetime_convert()),
		dbesc(dirname($hub))
	);

	// synchronous message types are handled immediately
	// async messages remain in the queue until processed.

	if(intval($outq['outq_async']))
		remove_queue_item($outq['outq_hash'],$outq['outq_channel']);

	logger('zot_process_response: ' . print_r($x,true), LOGGER_DEBUG);
}

/**
 * @brief
 *
 * We received a notification packet (in mod_post) that a message is waiting for us, and we've verified the sender.
 * Check if the site is using zot6 delivery and includes a verified HTTP Signature, signed content, and a 'msg' field,
 * and also that the signer and the sender match.
 * If that happens, we do not need to fetch/pickup the message - we have it already and it is verified.
 * Translate it into the form we need for zot_import() and import it.
 *
 * Otherwise send back a pickup message, using our message tracking ID ($arr['secret']), which we will sign with our site
 * private key.
 * The entire pickup message is encrypted with the remote site's public key.
 * If everything checks out on the remote end, we will receive back a packet containing one or more messages,
 * which will be processed and delivered before this function ultimately returns.
 *
 * @see zot_import()
 *
 * @param array $arr
 *     decrypted and json decoded notify packet from remote site
 * @return array from zot_import()
 */
function zot_fetch($arr) {

	logger('zot_fetch: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);

	$url = $arr['sender']['url'] . $arr['callback'];

	$import = null;
	$hubs   = null;

	$zret = zot6_check_sig();

	if($zret['success'] && $zret['hubloc'] && $zret['hubloc']['hubloc_guid'] === $data['sender']['guid'] && $data['msg']) {
		logger('zot6_delivery',LOGGER_DEBUG);
		logger('zot6_data: ' . print_r($data,true),LOGGER_DATA);

		$ret['collected'] = true;

		$import = [ 'success' => true, 'body' => json_encode( [ 'success' => true, 'pickup' => [ [ 'notify' => $data, 'message' => json_decode($data['msg'],true) ] ] ] ) ];
		$hubs = [ $zret['hubloc'] ] ;
	}

	if(! $hubs) {
		// set $multiple param on zot_gethub() to return all matching hubs
		// This allows us to recover from re-installs when a redundant (but invalid) hubloc for
		// this identity is widely dispersed throughout the network.

		$hubs = zot_gethub($arr['sender'],true);
	}

	if(! $hubs) {
		logger('No hub: ' . print_r($arr['sender'],true));
		return;
	}

	foreach($hubs as $hub) {

		if(! $import) {
			$secret = substr(preg_replace('/[^0-9a-fA-F]/','',$arr['secret']),0,64);

			$data = [
				'type'         => 'pickup',
				'url'          => z_root(),
				'callback_sig' => base64url_encode(rsa_sign(z_root() . '/post', get_config('system','prvkey'))),
				'callback'     => z_root() . '/post',
				'secret'       => $secret,
				'secret_sig'   => base64url_encode(rsa_sign($secret, get_config('system','prvkey')))
			];

			$algorithm = zot_best_algorithm($hub['site_crypto']);
			$datatosend = json_encode(crypto_encapsulate(json_encode($data),$hub['hubloc_sitekey'], $algorithm));

			$import = zot_zot($url,$datatosend);
		}
		else {
			$algorithm = zot_best_algorithm($hub['site_crypto']);
		}

		$result = zot_import($import, $arr['sender']['url']);

		if($result) {
			$result = crypto_encapsulate(json_encode($result),$hub['hubloc_sitekey'], $algorithm);
			return $result;
		}

	}

	return;
}

/**
 * @brief Process incoming array of messages.
 *
 * Process an incoming array of messages which were obtained via pickup, and
 * import, update, delete as directed.
 *
 * The message types handled here are 'activity' (e.g. posts), 'mail',
 * 'profile', 'location' and 'channel_sync'.
 *
 * @param array $arr
 *  'pickup' structure returned from remote site
 * @param string $sender_url
 *  the url specified by the sender in the initial communication.
 *  We will verify the sender and url in each returned message structure and
 *  also verify that all the messages returned match the site url that we are
 *  currently processing.
 *
 * @returns array
 *   Suitable for logging remotely, enumerating the processing results of each message/recipient combination
 *   * [0] => \e string $channel_hash
 *   * [1] => \e string $delivery_status
 *   * [2] => \e string $address
 */
function zot_import($arr, $sender_url) {

	$data = json_decode($arr['body'], true);

	if(! $data) {
		logger('Empty body');
		return array();
	}

	if(array_key_exists('iv', $data)) {
		$data = json_decode(crypto_unencapsulate($data,get_config('system','prvkey')),true);
	}

	if(! is_array($data)) {
		logger('decode error');
		return array();
	}

	if(! $data['success']) {
		if($data['message'])
			logger('remote pickup failed: ' . $data['message']);
		return false;
	}

	$incoming = $data['pickup'];

	$return = array();

	if(is_array($incoming)) {
		foreach($incoming as $i) {
			if(! is_array($i)) {
				logger('incoming is not an array');
				continue;
			}

			$result = null;

			if(array_key_exists('iv',$i['notify'])) {
				$i['notify'] = json_decode(crypto_unencapsulate($i['notify'],get_config('system','prvkey')),true);
			}

			logger('Notify: ' . print_r($i['notify'],true), LOGGER_DATA, LOG_DEBUG);

			if(! is_array($i['notify'])) {
				logger('decode error');
				continue;
			}


			$hub = zot_gethub($i['notify']['sender']);
			if((! $hub) || ($hub['hubloc_url'] != $sender_url)) {
				logger('Potential forgery: wrong site for sender: ' . $sender_url . ' != ' . print_r($i['notify'],true));
				continue;
			}

			$message_request = ((array_key_exists('message_id',$i['notify'])) ? true : false);
			if($message_request)
				logger('processing message request');

			$i['notify']['sender']['hash'] = make_xchan_hash($i['notify']['sender']['guid'],$i['notify']['sender']['guid_sig']);
			$deliveries = null;

			if(array_key_exists('message',$i) && array_key_exists('type',$i['message']) && $i['message']['type'] === 'rating') {
				// rating messages are processed only by directory servers
				logger('Rating received: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
				$result = process_rating_delivery($i['notify']['sender'],$i['message']);
				continue;
			}

			if(array_key_exists('recipients',$i['notify']) && count($i['notify']['recipients'])) {
				logger('specific recipients');
				$recip_arr = array();
				foreach($i['notify']['recipients'] as $recip) {
					if(is_array($recip)) {
						$recip_arr[] =  make_xchan_hash($recip['guid'],$recip['guid_sig']);
					}
				}

				$r = false;
				if($recip_arr) {
					stringify_array_elms($recip_arr);
					$recips = implode(',',$recip_arr);
					$r = q("select channel_hash as hash from channel where channel_hash in ( " . $recips . " )
						and channel_removed = 0 ");
				}

				if(! $r) {
					logger('recips: no recipients on this site');
					continue;
				}

				// It's a specifically targetted post. If we were sent a public_scope hint (likely),
				// get rid of it so that it doesn't get stored and cause trouble.

				if(($i) && is_array($i) && array_key_exists('message',$i) && is_array($i['message'])
					&& $i['message']['type'] === 'activity' && array_key_exists('public_scope',$i['message']))
					unset($i['message']['public_scope']);

				$deliveries = $r;

				// We found somebody on this site that's in the recipient list.

			}
			else {
				if(($i['message']) && (array_key_exists('flags',$i['message'])) && (in_array('private',$i['message']['flags'])) && $i['message']['type'] === 'activity') {
					if(array_key_exists('public_scope',$i['message']) && $i['message']['public_scope'] === 'public') {
						// This should not happen but until we can stop it...
						logger('private message was delivered with no recipients.');
						continue;
					}
				}

				logger('public post');

				// Public post. look for any site members who are or may be accepting posts from this sender
				// and who are allowed to see them based on the sender's permissions

				$deliveries = allowed_public_recips($i);

				if($i['message'] && array_key_exists('type',$i['message']) && $i['message']['type'] === 'location') {
					$sys = get_sys_channel();
					$deliveries = array(array('hash' => $sys['xchan_hash']));
				}

				// if the scope is anything but 'public' we're going to store it as private regardless
				// of the private flag on the post.

				if($i['message'] && array_key_exists('public_scope',$i['message'])
					&& $i['message']['public_scope'] !== 'public') {

					if(! array_key_exists('flags',$i['message']))
						$i['message']['flags'] = array();
					if(! in_array('private',$i['message']['flags']))
						$i['message']['flags'][] = 'private';
				}
			}

			// Go through the hash array and remove duplicates. array_unique() won't do this because the array is more than one level.

			$no_dups = array();
			if($deliveries) {
				foreach($deliveries as $d) {
					if(! is_array($d)) {
						logger('Delivery hash array is not an array: ' . print_r($d,true));
						continue;
					}
					if(! in_array($d['hash'],$no_dups))
						$no_dups[] = $d['hash'];
				}

				if($no_dups) {
					$deliveries = array();
					foreach($no_dups as $n) {
						$deliveries[] = array('hash' => $n);
					}
				}
			}

			if(! $deliveries) {
				logger('No deliveries on this site');
				continue;
			}

			if($i['message']) {
				if($i['message']['type'] === 'activity') {
					$arr = get_item_elements($i['message']);

					$v = validate_item_elements($i['message'],$arr);

					if(! $v['success']) {
						logger('Activity rejected: ' . $v['message'] . ' ' . print_r($i['message'],true));
						continue;
					}

					logger('Activity received: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
					logger('Activity recipients: ' . print_r($deliveries,true), LOGGER_DATA, LOG_DEBUG);

					$relay = ((array_key_exists('flags',$i['message']) && in_array('relay',$i['message']['flags'])) ? true : false);
					$result = process_delivery($i['notify']['sender'],$arr,$deliveries,$relay,false,$message_request);
				}
				elseif($i['message']['type'] === 'mail') {
					$arr = get_mail_elements($i['message']);

					logger('Mail received: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
					logger('Mail recipients: ' . print_r($deliveries,true), LOGGER_DATA, LOG_DEBUG);

					$result = process_mail_delivery($i['notify']['sender'],$arr,$deliveries);
				}
				elseif($i['message']['type'] === 'profile') {
					$arr = get_profile_elements($i['message']);

					logger('Profile received: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
					logger('Profile recipients: ' . print_r($deliveries,true), LOGGER_DATA, LOG_DEBUG);

					$result = process_profile_delivery($i['notify']['sender'],$arr,$deliveries);
				}
				elseif($i['message']['type'] === 'channel_sync') {
					// $arr = get_channelsync_elements($i['message']);

					$arr = $i['message'];

					logger('Channel sync received: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
					logger('Channel sync recipients: ' . print_r($deliveries,true), LOGGER_DATA, LOG_DEBUG);

					$result = process_channel_sync_delivery($i['notify']['sender'],$arr,$deliveries);
				}
				elseif($i['message']['type'] === 'location') {
					$arr = $i['message'];

					logger('Location message received: ' . print_r($arr,true), LOGGER_DATA, LOG_DEBUG);
					logger('Location message recipients: ' . print_r($deliveries,true), LOGGER_DATA, LOG_DEBUG);

					$result = process_location_delivery($i['notify']['sender'],$arr,$deliveries);
				}
			}
			if($result){
				$return = array_merge($return, $result);
			}
		}
	}

	return $return;
}

/**
 * @brief
 *
 * A public message with no listed recipients can be delivered to anybody who
 * has PERMS_NETWORK for that type of post, PERMS_AUTHED (in-network senders are
 * by definition authenticated) or PERMS_SITE and is one the same site,
 * or PERMS_SPECIFIC and the sender is a contact who is granted permissions via
 * their connection permissions in the address book.
 * Here we take a given message and construct a list of hashes of everybody
 * on the site that we should try and deliver to.
 * Some of these will be rejected, but this gives us a place to start.
 *
 * @param array $msg
 * @return NULL|array
 */
function public_recips($msg) {

	require_once('include/channel.php');

	$check_mentions = false;
	$include_sys = false;

	if($msg['message']['type'] === 'activity') {
		$disable_discover_tab = get_config('system','disable_discover_tab') || get_config('system','disable_discover_tab') === false;
		if(! $disable_discover_tab)
			$include_sys = true;

		$perm = 'send_stream';

		if(array_key_exists('flags',$msg['message']) && in_array('thread_parent', $msg['message']['flags'])) {
			// check mention recipient permissions on top level posts only
			$check_mentions = true;
		}
		else {

			// This doesn't look like it works so I have to explain what happened. These are my
			// notes (below) from when I got this section of code working. You would think that
			// we only have to find those with the requisite stream or comment permissions,
			// depending on whether this is a top-level post or a comment - but you would be wrong.

			// ... so public_recips and allowed_public_recips is working so much better
			// than before, but was still not quite right. We seem to be getting all the right
			// results for top-level posts now, but comments aren't getting through on channels
			// for which we've allowed them to send us their stream, but not comment on our posts.
			// The reason is we were seeing if they could comment - and we only need to do that if
			// we own the post. If they own the post, we only need to check if they can send us their stream.

			// if this is a comment and it wasn't sent by the post owner, check to see who is allowing them to comment.
			// We should have one specific recipient and this step shouldn't be needed unless somebody stuffed up
			// their software. We may need this step to protect us from bad guys intentionally stuffing up their software.
			// If it is sent by the post owner, we don't need to do this. We only need to see who is receiving the
			// owner's stream (which was already set above) - as they control the comment permissions, not us.

			// Note that by doing this we introduce another bug because some public forums have channel_w_stream
			// permissions set to themselves only. We also need in this function to add these public forums to the
			// public recipient list based on if they are tagged or not and have tag permissions. This is complicated
			// by the fact that this activity doesn't have the public forum tag. It's the parent activity that
			// contains the tag. we'll solve that further below.

			if($msg['notify']['sender']['guid_sig'] != $msg['message']['owner']['guid_sig']) {
				$perm = 'post_comments';
			}
		}
	}
	elseif($msg['message']['type'] === 'mail')
		$perm = 'post_mail';

	$r = array();

	$c = q("select channel_id, channel_hash from channel where channel_removed = 0");
	if($c) {
		foreach($c as $cc) {
			if(perm_is_allowed($cc['channel_id'],$msg['notify']['sender']['hash'],$perm)) {
				$r[] = [ 'hash' => $cc['channel_hash'] ];
			}
		}
	}

	// logger('message: ' . print_r($msg['message'],true));

	if($include_sys && array_key_exists('public_scope',$msg['message']) && $msg['message']['public_scope'] === 'public') {
		$sys = get_sys_channel();
		if($sys)
			$r[] = [ 'hash' => $sys['channel_hash'] ];
	}

	// look for any public mentions on this site
	// They will get filtered by tgroup_check() so we don't need to check permissions now

	if($check_mentions) {
		// It's a top level post. Look at the tags. See if any of them are mentions and are on this hub.
		if($msg['message']['tags']) {
			if(is_array($msg['message']['tags']) && $msg['message']['tags']) {
				foreach($msg['message']['tags'] as $tag) {
					if(($tag['type'] === 'mention' || $tag['type'] === 'forum') && (strpos($tag['url'],z_root()) !== false)) {
						$address = basename($tag['url']);
						if($address) {
							$z = q("select channel_hash as hash from channel where channel_address = '%s'
								and channel_removed = 0 limit 1",
								dbesc($address)
							);
							if($z)
								$r = array_merge($r,$z);
						}
					}
				}
			}
		}
	}
	else {
		// This is a comment. We need to find any parent with ITEM_UPLINK set. But in fact, let's just return
		// everybody that stored a copy of the parent. This way we know we're covered. We'll check the
		// comment permissions when we deliver them.

		if($msg['message']['message_top']) {
			$z = q("select owner_xchan as hash from item where parent_mid = '%s' ",
				dbesc($msg['message']['message_top'])
			);
			if($z)
				$r = array_merge($r,$z);
		}
	}

	// There are probably a lot of duplicates in $r at this point. We need to filter those out.
	// It's a bit of work since it's a multi-dimensional array

	if($r) {
		$uniq = array();

		foreach($r as $rr) {
			if(! in_array($rr['hash'],$uniq))
				$uniq[] = $rr['hash'];
		}
		$r = array();
		foreach($uniq as $rr) {
			$r[] = array('hash' => $rr);
		}
	}

	logger('public_recips: ' . print_r($r,true), LOGGER_DATA, LOG_DEBUG);
	return $r;
}

/**
 * @brief This is the second part of public_recips().
 *
 * We'll find all the channels willing to accept public posts from us, then
 * match them against the sender privacy scope and see who in that list that
 * the sender is allowing.
 *
 * @see public_recipes()
 * @param array $msg
 * @return array
 */
function allowed_public_recips($msg) {

	logger('allowed_public_recips: ' . print_r($msg,true),LOGGER_DATA, LOG_DEBUG);

	if(array_key_exists('public_scope',$msg['message']))
		$scope = $msg['message']['public_scope'];

	// Mail won't have a public scope.
	// in fact, it's doubtful mail will ever get here since it almost universally
	// has a recipient, but in fact we don't require this, so it's technically
	// possible to send mail to anybody that's listening.

	$recips = public_recips($msg);

	if(! $recips)
		return $recips;

	if($msg['message']['type'] === 'mail')
		return $recips;

	if($scope === 'public' || $scope === 'network: red' || $scope === 'authenticated')
		return $recips;

	if(strpos($scope,'site:') === 0) {
		if(($scope === 'site: ' . App::get_hostname()) && ($msg['notify']['sender']['url'] === z_root()))
			return $recips;
		else
			return array();
	}

	$hash = make_xchan_hash($msg['notify']['sender']['guid'],$msg['notify']['sender']['guid_sig']);

	if($scope === 'self') {
		foreach($recips as $r)
			if($r['hash'] === $hash)
				return array('hash' => $hash);
	}

	// note: we shouldn't ever see $scope === 'specific' in this function, but handle it anyway

	if($scope === 'contacts' || $scope === 'any connections' || $scope === 'specific') {
		$condensed_recips = array();
		foreach($recips as $rr)
			$condensed_recips[] = $rr['hash'];

		$results = array();
		$r = q("select channel_hash as hash from channel left join abook on abook_channel = channel_id where abook_xchan = '%s' and channel_removed = 0 ",
			dbesc($hash)
		);
		if($r) {
			foreach($r as $rr)
				if(in_array($rr['hash'],$condensed_recips))
					$results[] = array('hash' => $rr['hash']);
		}
		return $results;
	}

	return array();
}

/**
 * @brief
 *
 * @param array $sender
 * @param array $arr
 * @param array $deliveries
 * @param boolean $relay
 * @param boolean $public (optional) default false
 * @param boolean $request (optional) default false
 * @return array
 */
function process_delivery($sender, $arr, $deliveries, $relay, $public = false, $request = false) {

	$result = array();

	$result['site'] = z_root();

	// We've validated the sender. Now make sure that the sender is the owner or author

	if(! $public) {
		if($sender['hash'] != $arr['owner_xchan'] && $sender['hash'] != $arr['author_xchan']) {
			logger("Sender {$sender['hash']} is not owner {$arr['owner_xchan']} or author {$arr['author_xchan']} - mid {$arr['mid']}");
			return;
		}
	}

	foreach($deliveries as $d) {
		$local_public = $public;

		$DR = new Zotlabs\Lib\DReport(z_root(),$sender['hash'],$d['hash'],$arr['mid']);

		$r = q("select * from channel where channel_hash = '%s' limit 1",
			dbesc($d['hash'])
		);

		if(! $r) {
			$DR->update('recipient not found');
			$result[] = $DR->get();
			continue;
		}

		$channel = $r[0];
		$DR->addto_recipient($channel['channel_name'] . ' <' . channel_reddress($channel) . '>');

		/* blacklisted channels get a permission denied, no special message to tip them off */

		if(! check_channelallowed($sender['hash'])) {
			$DR->update('permission denied');
			$result[] = $DR->get();
			continue;
		}

		/**
		 * @FIXME: Somehow we need to block normal message delivery from our clones, as the delivered
		 * message doesn't have ACL information in it as the cloned copy does. That copy
		 * will normally arrive first via sync delivery, but this isn't guaranteed.
		 * There's a chance the current delivery could take place before the cloned copy arrives
		 * hence the item could have the wrong ACL and *could* be used in subsequent deliveries or
		 * access checks. So far all attempts at identifying this situation precisely
		 * have caused issues with delivery of relayed comments.
		 */

//		if(($d['hash'] === $sender['hash']) && ($sender['url'] !== z_root()) && (! $relay)) {
//			$DR->update('self delivery ignored');
//			$result[] = $DR->get();
//			continue;
//		}

		// allow public postings to the sys channel regardless of permissions, but not
		// for comments travelling upstream. Wait and catch them on the way down.
		// They may have been blocked by the owner.

		if(intval($channel['channel_system']) && (! $arr['item_private']) && (! $relay)) {
			$local_public = true;

			$r = q("select xchan_selfcensored from xchan where xchan_hash = '%s' limit 1",
				dbesc($sender['hash'])
			);
			// don't import sys channel posts from selfcensored authors
			if($r && (intval($r[0]['xchan_selfcensored']))) {
				$local_public = false;
				continue;
			}
			if(! \Zotlabs\Lib\MessageFilter::evaluate($arr,get_config('system','pubstream_incl'),get_config('system','pubstream_excl'))) {
				$local_public = false;
				continue;
			}
		}

		$tag_delivery = tgroup_check($channel['channel_id'],$arr);

		$perm = 'send_stream';
		if(($arr['mid'] !== $arr['parent_mid']) && ($relay))
			$perm = 'post_comments';

		// This is our own post, possibly coming from a channel clone

		if($arr['owner_xchan'] == $d['hash']) {
			$arr['item_wall'] = 1;
		}
		else {
			$arr['item_wall'] = 0;
		}
		

                if ((! $tag_delivery) && (! $local_public)) {
                        $allowed = (perm_is_allowed($channel['channel_id'],$sender['hash'],$perm));

		        if((! $allowed) && $perm == 'post_comments') {
                                $parent = q("select * from item where mid = '%s' and uid = %d limit 1",
                                        dbesc($arr['parent_mid']),
                                        intval($channel['channel_id'])
                                );
                                if ($parent) {
                                        $allowed = can_comment_on_post($d['hash'],$parent[0]);
                                }
                        }
        
                        if (! $allowed) {
			        logger("permission denied for delivery to channel {$channel['channel_id']} {$channel['channel_address']}");
			        $DR->update('permission denied');
			        $result[] = $DR->get();
			        continue;
		        }
                }

		if($arr['mid'] != $arr['parent_mid']) {

			// check source route.
			// We are only going to accept comments from this sender if the comment has the same route as the top-level-post,
			// this is so that permissions mismatches between senders apply to the entire conversation
			// As a side effect we will also do a preliminary check that we have the top-level-post, otherwise
			// processing it is pointless.

			$r = q("select route, id from item where mid = '%s' and uid = %d limit 1",
				dbesc($arr['parent_mid']),
				intval($channel['channel_id'])
			);
			if(! $r) {
				$DR->update('comment parent not found');
				$result[] = $DR->get();

				// We don't seem to have a copy of this conversation or at least the parent
				// - so request a copy of the entire conversation to date.
				// Don't do this if it's a relay post as we're the ones who are supposed to
				// have the copy and we don't want the request to loop.
				// Also don't do this if this comment came from a conversation request packet.
				// It's possible that comments are allowed but posting isn't and that could
				// cause a conversation fetch loop. We can detect these packets since they are
				// delivered via a 'notify' packet type that has a message_id element in the
				// initial zot packet (just like the corresponding 'request' packet type which
				// makes the request).
				// We'll also check the send_stream permission - because if it isn't allowed,
				// the top level post is unlikely to be imported and
				// this is just an exercise in futility.

				if((! $relay) && (! $request) && (! $local_public)
					&& perm_is_allowed($channel['channel_id'],$sender['hash'],'send_stream')) {
					Zotlabs\Daemon\Master::Summon(array('Notifier', 'request', $channel['channel_id'], $sender['hash'], $arr['parent_mid']));
				}
				continue;
			}
			if($relay) {
				// reset the route in case it travelled a great distance upstream
				// use our parent's route so when we go back downstream we'll match
				// with whatever route our parent has.
				$arr['route'] = $r[0]['route'];
			}
			else {

				// going downstream check that we have the same upstream provider that
				// sent it to us originally. Ignore it if it came from another source
				// (with potentially different permissions).
				// only compare the last hop since it could have arrived at the last location any number of ways.
				// Always accept empty routes and firehose items (route contains 'undefined') .

				$existing_route = explode(',', $r[0]['route']);
				$routes = count($existing_route);
				if($routes) {
					$last_hop = array_pop($existing_route);
					$last_prior_route = implode(',',$existing_route);
				}
				else {
					$last_hop = '';
					$last_prior_route = '';
				}

				if(in_array('undefined',$existing_route) || $last_hop == 'undefined' || $sender['hash'] == 'undefined')
					$last_hop = '';

				$current_route = (($arr['route']) ? $arr['route'] . ',' : '') . $sender['hash'];

				if($last_hop && $last_hop != $sender['hash']) {
					logger('comment route mismatch: parent route = ' . $r[0]['route'] . ' expected = ' . $current_route, LOGGER_DEBUG);
					logger('comment route mismatch: parent msg = ' . $r[0]['id'],LOGGER_DEBUG);
					$DR->update('comment route mismatch');
					$result[] = $DR->get();
					continue;
				}

				// we'll add sender['hash'] onto this when we deliver it. $last_prior_route now has the previously stored route
				// *except* for the sender['hash'] which would've been the last hop before it got to us.

				$arr['route'] = $last_prior_route;
			}
		}

		$ab = q("select * from abook where abook_channel = %d and abook_xchan = '%s'",
			intval($channel['channel_id']),
			dbesc($arr['owner_xchan'])
		);
		$abook = (($ab) ? $ab[0] : null);

		if(intval($arr['item_deleted'])) {

			// remove_community_tag is a no-op if this isn't a community tag activity
			remove_community_tag($sender,$arr,$channel['channel_id']);

			// set these just in case we need to store a fresh copy of the deleted post.
			// This could happen if the delete got here before the original post did.

			$arr['aid'] = $channel['channel_account_id'];
			$arr['uid'] = $channel['channel_id'];

			$item_id = delete_imported_item($sender,$arr,$channel['channel_id'],$relay);
			$DR->update(($item_id) ? 'deleted' : 'delete_failed');
			$result[] = $DR->get();

			if($relay && $item_id) {
				logger('process_delivery: invoking relay');
				Zotlabs\Daemon\Master::Summon(array('Notifier','relay',intval($item_id)));
				$DR->update('relayed');
				$result[] = $DR->get();
			}

			continue;
		}


		$r = q("select * from item where mid = '%s' and uid = %d limit 1",
			dbesc($arr['mid']),
			intval($channel['channel_id'])
		);
		if($r) {
			// We already have this post.
			$item_id = $r[0]['id'];

			if(intval($r[0]['item_deleted'])) {
				// It was deleted locally.
				$DR->update('update ignored');
				$result[] = $DR->get();

				continue;
			}
			// Maybe it has been edited?
			elseif($arr['edited'] > $r[0]['edited']) {
				$arr['id'] = $r[0]['id'];
				$arr['uid'] = $channel['channel_id'];
				if(($arr['mid'] == $arr['parent_mid']) && (! post_is_importable($arr,$abook))) {
					$DR->update('update ignored');
					$result[] = $DR->get();
				}
				else {
					$item_result = update_imported_item($sender,$arr,$r[0],$channel['channel_id'],$tag_delivery);
					$DR->update('updated');
					$result[] = $DR->get();
					if(! $relay)
						add_source_route($item_id,$sender['hash']);
				}
			}
			else {
				$DR->update('update ignored');
				$result[] = $DR->get();

				// We need this line to ensure wall-to-wall comments are relayed (by falling through to the relay bit),
				// and at the same time not relay any other relayable posts more than once, because to do so is very wasteful.
				if(! intval($r[0]['item_origin']))
					continue;
			}
		}
		else {
			$arr['aid'] = $channel['channel_account_id'];
			$arr['uid'] = $channel['channel_id'];

			// if it's a sourced post, call the post_local hooks as if it were
			// posted locally so that crosspost connectors will be triggered.

			if(check_item_source($arr['uid'], $arr)) {
				/**
				 * @hooks post_local
				 *   Called when an item has been posted on this machine via mod/item.php (also via API).
				 *   * \e array with an item
				 */
				call_hooks('post_local', $arr);
			}

			$item_id = 0;

			if(($arr['mid'] == $arr['parent_mid']) && (! post_is_importable($arr,$abook))) {
				$DR->update('post ignored');
				$result[] = $DR->get();
			}
			else {
				$item_result = item_store($arr);
				if($item_result['success']) {
					$item_id = $item_result['item_id'];
					$parr = [
							'item_id' => $item_id,
							'item' => $arr,
							'sender' => $sender,
							'channel' => $channel
					];
					/**
					 * @hooks activity_received
					 *   Called when an activity (post, comment, like, etc.) has been received from a zot source.
					 *   * \e int \b item_id
					 *   * \e array \b item
					 *   * \e array \b sender
					 *   * \e array \b channel
					 */
					call_hooks('activity_received', $parr);
					// don't add a source route if it's a relay or later recipients will get a route mismatch
					if(! $relay)
						add_source_route($item_id,$sender['hash']);
				}
				$DR->update(($item_id) ? 'posted' : 'storage failed: ' . $item_result['message']);
				$result[] = $DR->get();
			}
		}

		// preserve conversations with which you are involved from expiration

		$stored = (($item_result && $item_result['item']) ? $item_result['item'] : false);
		if((is_array($stored)) && ($stored['id'] != $stored['parent'])
			&& ($stored['author_xchan'] === $channel['channel_hash'])) {
			retain_item($stored['item']['parent']);
		}

		if($relay && $item_id) {
			logger('Invoking relay');
			Zotlabs\Daemon\Master::Summon(array('Notifier','relay',intval($item_id)));
			$DR->addto_update('relayed');
			$result[] = $DR->get();
		}
	}

	if(! $deliveries)
		$result[] = array('', 'no recipients', '', $arr['mid']);

	logger('Local results: ' . print_r($result, true), LOGGER_DEBUG);

	return $result;
}

/**
 * @brief Remove community tag.
 *
 * @param array $sender an associative array with
 *   * \e string \b hash a xchan_hash
 * @param array $arr an associative array
 *   * \e int \b verb
 *   * \e int \b obj_type
 *   * \e int \b mid
 * @param int $uid
 */
function remove_community_tag($sender, $arr, $uid) {

	if(! (activity_match($arr['verb'], ACTIVITY_TAG) && ($arr['obj_type'] == ACTIVITY_OBJ_TAGTERM)))
		return;

	logger('remove_community_tag: invoked');

	if(! get_pconfig($uid,'system','blocktags')) {
		logger('Permission denied.');
		return;
	}

	$r = q("select * from item where mid = '%s' and uid = %d limit 1",
		dbesc($arr['mid']),
		intval($uid)
	);
	if(! $r) {
		logger('No item');
		return;
	}

	if(($sender['hash'] != $r[0]['owner_xchan']) && ($sender['hash'] != $r[0]['author_xchan'])) {
		logger('Sender not authorised.');
		return;
	}

	$i = $r[0];

	if($i['target'])
		$i['target'] = json_decode($i['target'],true);
	if($i['object'])
		$i['object'] = json_decode($i['object'],true);

	if(! ($i['target'] && $i['object'])) {
		logger('No target/object');
		return;
	}

	$message_id = $i['target']['id'];

	$r = q("select id from item where mid = '%s' and uid = %d limit 1",
		dbesc($message_id),
		intval($uid)
	);
	if(! $r) {
		logger('No parent message');
		return;
	}

	q("delete from term where uid = %d and oid = %d and otype = %d and ttype in  ( %d, %d ) and term = '%s' and url = '%s'",
		intval($uid),
		intval($r[0]['id']),
		intval(TERM_OBJ_POST),
		intval(TERM_HASHTAG),
		intval(TERM_COMMUNITYTAG),
		dbesc($i['object']['title']),
		dbesc(get_rel_link($i['object']['link'],'alternate'))
	);
}

/**
 * @brief Updates an imported item.
 *
 * @see item_store_update()
 *
 * @param array $sender
 * @param array $item
 * @param array $orig
 * @param int $uid
 * @param boolean $tag_delivery
 */
function update_imported_item($sender, $item, $orig, $uid, $tag_delivery) {

	// If this is a comment being updated, remove any privacy information
	// so that item_store_update will set it from the original.

	if($item['mid'] !== $item['parent_mid']) {
		unset($item['allow_cid']);
		unset($item['allow_gid']);
		unset($item['deny_cid']);
		unset($item['deny_gid']);
		unset($item['item_private']);
	}

	// we need the tag_delivery check for downstream flowing posts as the stored post
	// may have a different owner than the one being transmitted.

	if(($sender['hash'] != $orig['owner_xchan'] && $sender['hash'] != $orig['author_xchan']) && (! $tag_delivery)) {
		logger('sender is not owner or author');
		return;
	}


	$x = item_store_update($item);

	// If we're updating an event that we've saved locally, we store the item info first
	// because event_addtocal will parse the body to get the 'new' event details

	if($orig['resource_type'] === 'event') {
		$res = event_addtocal($orig['id'], $uid);
		if(! $res)
			logger('update event: failed');
	}

	if(! $x['item_id'])
		logger('update_imported_item: failed: ' . $x['message']);
	else
		logger('update_imported_item');

	return $x;
}

/**
 * @brief Deletes an imported item.
 *
 * @param array $sender
 *   * \e string \b hash a xchan_hash
 * @param array $item
 * @param int $uid
 * @param boolean $relay
 * @return boolean|int post_id
 */
function delete_imported_item($sender, $item, $uid, $relay) {

	logger('invoked', LOGGER_DEBUG);

	$ownership_valid = false;
	$item_found = false;
	$post_id = 0;

	$r = q("select id, author_xchan, owner_xchan, source_xchan, item_deleted from item where ( author_xchan = '%s' or owner_xchan = '%s' or source_xchan = '%s' )
		and mid = '%s' and uid = %d limit 1",
		dbesc($sender['hash']),
		dbesc($sender['hash']),
		dbesc($sender['hash']),
		dbesc($item['mid']),
		intval($uid)
	);

	if($r) {
		if($r[0]['author_xchan'] === $sender['hash'] || $r[0]['owner_xchan'] === $sender['hash'] || $r[0]['source_xchan'] === $sender['hash'])
			$ownership_valid = true;

		$post_id = $r[0]['id'];
		$item_found = true;
	}
	else {

		// perhaps the item is still in transit and the delete notification got here before the actual item did. Store it with the deleted flag set.
		// item_store() won't try to deliver any notifications or start delivery chains if this flag is set.
		// This means we won't end up with potentially even more delivery threads trying to push this delete notification.
		// But this will ensure that if the (undeleted) original post comes in at a later date, we'll reject it because it will have an older timestamp.

		logger('delete received for non-existent item - storing item data.');

		if($item['author_xchan'] === $sender['hash'] || $item['owner_xchan'] === $sender['hash'] || $item['source_xchan'] === $sender['hash']) {
			$ownership_valid = true;
			$item_result = item_store($item);
			$post_id = $item_result['item_id'];
		}
	}

	if($ownership_valid === false) {
		logger('delete_imported_item: failed: ownership issue');
		return false;
	}

	require_once('include/items.php');

	if($item_found) {
		if(intval($r[0]['item_deleted'])) {
			logger('delete_imported_item: item was already deleted');
			if(! $relay)
				return false;

			// This is a bit hackish, but may have to suffice until the notification/delivery loop is optimised
			// a bit further. We're going to strip the ITEM_ORIGIN on this item if it's a comment, because
			// it was already deleted, and we're already relaying, and this ensures that no other process or
			// code path downstream can relay it again (causing a loop). Since it's already gone it's not coming
			// back, and we aren't going to (or shouldn't at any rate) delete it again in the future - so losing
			// this information from the metadata should have no other discernible impact.

			if (($r[0]['id'] != $r[0]['parent']) && intval($r[0]['item_origin'])) {
				q("update item set item_origin = 0 where id = %d and uid = %d",
					intval($r[0]['id']),
					intval($r[0]['uid'])
				);
			}
		}

		require_once('include/items.php');

		// Use phased deletion to set the deleted flag, call both tag_deliver and the notifier to notify downstream channels
		// and then clean up after ourselves with a cron job after several days to do the delete_item_lowlevel() (DROPITEM_PHASE2).

		drop_item($post_id, false, DROPITEM_PHASE1);
		tag_deliver($uid, $post_id);
	}

	return $post_id;
}

function process_mail_delivery($sender, $arr, $deliveries) {

	$result = array();

	if($sender['hash'] != $arr['from_xchan']) {
		logger('process_mail_delivery: sender is not mail author');
		return;
	}

	foreach($deliveries as $d) {

		$DR = new Zotlabs\Lib\DReport(z_root(),$sender['hash'],$d['hash'],$arr['mid']);

		$r = q("select * from channel where channel_hash = '%s' limit 1",
			dbesc($d['hash'])
		);

		if(! $r) {
			$DR->update('recipient not found');
			$result[] = $DR->get();
			continue;
		}

		$channel = $r[0];
		$DR->addto_recipient($channel['channel_name'] . ' <' . channel_reddress($channel) . '>');

		/* blacklisted channels get a permission denied, no special message to tip them off */

		if(! check_channelallowed($sender['hash'])) {
			$DR->update('permission denied');
			$result[] = $DR->get();
			continue;
		}


		if(! perm_is_allowed($channel['channel_id'],$sender['hash'],'post_mail')) {

			/* 
			 * Always allow somebody to reply if you initiated the conversation. It's anti-social
			 * and a bit rude to send a private message to somebody and block their ability to respond.
			 * If you are being harrassed and want to put an end to it, delete the conversation.
			 */

			$return = false;
			if($arr['parent_mid']) {
				$return = q("select * from mail where mid = '%s' and channel_id = %d limit 1",
					dbesc($arr['parent_mid']),
					intval($channel['channel_id'])
				);
			}
			if(! $return) {
				logger("permission denied for mail delivery {$channel['channel_id']}");
				$DR->update('permission denied');
				$result[] = $DR->get();
				continue;
			}
		}


		$r = q("select id, conv_guid from mail where mid = '%s' and channel_id = %d limit 1",
			dbesc($arr['mid']),
			intval($channel['channel_id'])
		);
		if($r) {
			if(intval($arr['mail_recalled'])) {
                msg_drop(intval($r[0]['id']), intval($channel['channel_id']), dbesc($r[0]['conv_guid']));
				$DR->update('mail recalled');
				$result[] = $DR->get();
				logger('mail_recalled');
			}
			else {
				$DR->update('duplicate mail received');
				$result[] = $DR->get();
				logger('duplicate mail received');
			}
			continue;
		}
		else {
			$arr['account_id'] = $channel['channel_account_id'];
			$arr['channel_id'] = $channel['channel_id'];
			$item_id = mail_store($arr);
			$DR->update('mail delivered');
			$result[] = $DR->get();
		}
	}

	return $result;
}

/**
 * @brief Processes delivery of rating.
 *
 * @param array $sender
 *   * \e string \b hash a xchan_hash
 * @param array $arr
 */
function process_rating_delivery($sender, $arr) {

	logger('process_rating_delivery: ' . print_r($arr,true));

	if(! $arr['target'])
		return;

	$z = q("select xchan_pubkey from xchan where xchan_hash = '%s' limit 1",
		dbesc($sender['hash'])
	);

	if((! $z) || (! rsa_verify($arr['target'] . '.' . $arr['rating'] . '.' . $arr['rating_text'], base64url_decode($arr['signature']),$z[0]['xchan_pubkey']))) {
		logger('failed to verify rating');
		return;
	}

	$r = q("select * from xlink where xlink_xchan = '%s' and xlink_link = '%s' and xlink_static = 1 limit 1",
		dbesc($sender['hash']),
		dbesc($arr['target'])
	);

	if($r) {
		if($r[0]['xlink_updated'] >= $arr['edited']) {
			logger('rating message duplicate');
			return;
		}

		$x = q("update xlink set xlink_rating = %d, xlink_rating_text = '%s', xlink_sig = '%s', xlink_updated = '%s' where xlink_id = %d",
			intval($arr['rating']),
			dbesc($arr['rating_text']),
			dbesc($arr['signature']),
			dbesc(datetime_convert()),
			intval($r[0]['xlink_id'])
		);
		logger('rating updated');
	}
	else {
		$x = q("insert into xlink ( xlink_xchan, xlink_link, xlink_rating, xlink_rating_text, xlink_sig, xlink_updated, xlink_static )
			values( '%s', '%s', %d, '%s', '%s', '%s', 1 ) ",
			dbesc($sender['hash']),
			dbesc($arr['target']),
			intval($arr['rating']),
			dbesc($arr['rating_text']),
			dbesc($arr['signature']),
			dbesc(datetime_convert())
		);
		logger('rating created');
	}
}

/**
 * @brief Processes delivery of profile.
 *
 * @see import_directory_profile()
 * @param array $sender an associative array
 *   * \e string \b hash a xchan_hash
 * @param array $arr
 * @param array $deliveries (unused)
 */
function process_profile_delivery($sender, $arr, $deliveries) {

	logger('process_profile_delivery', LOGGER_DEBUG);

	$r = q("select xchan_addr from xchan where xchan_hash = '%s' limit 1",
			dbesc($sender['hash'])
	);
	if($r)
		import_directory_profile($sender['hash'], $arr, $r[0]['xchan_addr'], UPDATE_FLAGS_UPDATED, 0);
}


/**
 * @brief
 *
 * @param array $sender an associative array
 *   * \e string \b hash a xchan_hash
 * @param array $arr
 * @param array $deliveries (unused) deliveries is irrelevant
 */
function process_location_delivery($sender, $arr, $deliveries) {

	// deliveries is irrelevant
	logger('process_location_delivery', LOGGER_DEBUG);

	$r = q("select xchan_pubkey from xchan where xchan_hash = '%s' limit 1",
			dbesc($sender['hash'])
	);
	if($r)
		$sender['key'] = $r[0]['xchan_pubkey'];

	if(array_key_exists('locations',$arr) && $arr['locations']) {
		$x = sync_locations($sender,$arr,true);
		logger('results: ' . print_r($x,true), LOGGER_DEBUG);
		if($x['changed']) {
			$guid = random_string() . '@' . App::get_hostname();
			update_modtime($sender['hash'],$sender['guid'],$arr['locations'][0]['address'],UPDATE_FLAGS_UPDATED);
		}
	}
}

/**
 * @brief Checks for a moved UNO channel and sets the channel_moved flag.
 *
 * Currently the effect of this flag is to turn the channel into 'read-only' mode.
 * New content will not be processed (there was still an issue with blocking the
 * ability to post comments as of 10-Mar-2016).
 * We do not physically remove the channel at this time. The hub admin may choose
 * to do so, but is encouraged to allow a grace period of several days in case there
 * are any issues migrating content. This packet will generally be received by the
 * original site when the basic channel import has been processed.
 *
 * This will only be executed on the UNO system which is the old location
 * if a new location is reported and there is only one location record.
 * The rest of the hubloc syncronisation will be handled within
 * sync_locations
 *
 * @param string $sender_hash A channel hash
 * @param array $locations
 */
function check_location_move($sender_hash, $locations) {

	if(! $locations)
		return;

	if(count($locations) != 1)
		return;

	$loc = $locations[0];

	$r = q("select * from channel where channel_hash = '%s' limit 1",
		dbesc($sender_hash)
	);

	if(! $r)
		return;

	if($loc['url'] !== z_root()) {
		$x = q("update channel set channel_moved = '%s' where channel_hash = '%s' limit 1",
			dbesc($loc['url']),
			dbesc($sender_hash)
		);

		// federation plugins may wish to notify connections
		// of the move on singleton networks

		$arr = [
				'channel' => $r[0],
				'locations' => $locations
		];
		/**
		 * @hooks location_move
		 *   Called when a new location has been provided to a UNO channel (indicating a move rather than a clone).
		 *   * \e array \b channel
		 *   * \e array \b locations
		 */
		call_hooks('location_move', $arr);
	}
}


/**
 * @brief Synchronises locations.
 *
 * @param array $sender
 * @param array $arr
 * @param boolean $absolute (optional) default false
 * @return array
 */
function sync_locations($sender, $arr, $absolute = false) {

	$ret = array();

	if($arr['locations']) {

		if($absolute)
			check_location_move($sender['hash'],$arr['locations']);

		$xisting = q("select hubloc_id, hubloc_url, hubloc_sitekey from hubloc where hubloc_hash = '%s'",
			dbesc($sender['hash'])
		);

		// See if a primary is specified

		$has_primary = false;
		foreach($arr['locations'] as $location) {
			if($location['primary']) {
				$has_primary = true;
				break;
			}
		}

		// Ensure that they have one primary hub

		if(! $has_primary)
			$arr['locations'][0]['primary'] = true;

		foreach($arr['locations'] as $location) {
			if(! rsa_verify($location['url'],base64url_decode($location['url_sig']),$sender['key'])) {
				logger('Unable to verify site signature for ' . $location['url']);
				$ret['message'] .= sprintf( t('Unable to verify site signature for %s'), $location['url']) . EOL;
				continue;
			}

			for($x = 0; $x < count($xisting); $x ++) {
				if(($xisting[$x]['hubloc_url'] === $location['url'])
					&& ($xisting[$x]['hubloc_sitekey'] === $location['sitekey'])) {
					$xisting[$x]['updated'] = true;
				}
			}

			if(! $location['sitekey']) {
				logger('Empty hubloc sitekey. ' . print_r($location,true));
				continue;
			}

			// Catch some malformed entries from the past which still exist

			if(strpos($location['address'],'/') !== false)
				$location['address'] = substr($location['address'],0,strpos($location['address'],'/'));

			// match as many fields as possible in case anything at all changed.

			$r = q("select * from hubloc where hubloc_hash = '%s' and hubloc_guid = '%s' and hubloc_guid_sig = '%s' and hubloc_url = '%s' and hubloc_url_sig = '%s' and hubloc_host = '%s' and hubloc_addr = '%s' and hubloc_callback = '%s' and hubloc_sitekey = '%s' ",
				dbesc($sender['hash']),
				dbesc($sender['guid']),
				dbesc($sender['guid_sig']),
				dbesc($location['url']),
				dbesc($location['url_sig']),
				dbesc($location['host']),
				dbesc($location['address']),
				dbesc($location['callback']),
				dbesc($location['sitekey'])
			);
			if($r) {
				logger('Hub exists: ' . $location['url'], LOGGER_DEBUG);

				// update connection timestamp if this is the site we're talking to
				// This only happens when called from import_xchan

				$current_site = false;

				$t = datetime_convert('UTC','UTC','now - 15 minutes');

				if(array_key_exists('site',$arr) && $location['url'] == $arr['site']['url']) {
					q("update hubloc set hubloc_connected = '%s', hubloc_updated = '%s' where hubloc_id = %d and hubloc_connected < '%s'",
						dbesc(datetime_convert()),
						dbesc(datetime_convert()),
						intval($r[0]['hubloc_id']),
						dbesc($t)
					);
					$current_site = true;
				}

				if($current_site && intval($r[0]['hubloc_error'])) {
					q("update hubloc set hubloc_error = 0 where hubloc_id = %d",
						intval($r[0]['hubloc_id'])
					);
					if(intval($r[0]['hubloc_orphancheck'])) {
						q("update hubloc set hubloc_orphancheck = 0 where hubloc_id = %d",
							intval($r[0]['hubloc_id'])
						);
					}
					q("update xchan set xchan_orphan = 0 where xchan_orphan = 1 and xchan_hash = '%s'",
						dbesc($sender['hash'])
					);
				}

				// Remove pure duplicates
				if(count($r) > 1) {
					for($h = 1; $h < count($r); $h ++) {
						q("delete from hubloc where hubloc_id = %d",
							intval($r[$h]['hubloc_id'])
						);
						$what .= 'duplicate_hubloc_removed ';
						$changed = true;
					}
				}

				if(intval($r[0]['hubloc_primary']) && (! $location['primary'])) {
					$m = q("update hubloc set hubloc_primary = 0, hubloc_updated = '%s' where hubloc_id = %d",
						dbesc(datetime_convert()),
						intval($r[0]['hubloc_id'])
					);
					$r[0]['hubloc_primary'] = intval($location['primary']);
					hubloc_change_primary($r[0]);
					$what .= 'primary_hub ';
					$changed = true;
				}
				elseif((! intval($r[0]['hubloc_primary'])) && ($location['primary'])) {
					$m = q("update hubloc set hubloc_primary = 1, hubloc_updated = '%s' where hubloc_id = %d",
						dbesc(datetime_convert()),
						intval($r[0]['hubloc_id'])
					);
					// make sure hubloc_change_primary() has current data
					$r[0]['hubloc_primary'] = intval($location['primary']);
					hubloc_change_primary($r[0]);
					$what .= 'primary_hub ';
					$changed = true;
				}
				elseif($absolute) {
					// Absolute sync - make sure the current primary is correctly reflected in the xchan
					$pr = hubloc_change_primary($r[0]);
					if($pr) {
						$what .= 'xchan_primary ';
						$changed = true;
					}
				}
				if(intval($r[0]['hubloc_deleted']) && (! intval($location['deleted']))) {
					$n = q("update hubloc set hubloc_deleted = 0, hubloc_updated = '%s' where hubloc_id = %d",
						dbesc(datetime_convert()),
						intval($r[0]['hubloc_id'])
					);
					$what .= 'undelete_hub ';
					$changed = true;
				}
				elseif((! intval($r[0]['hubloc_deleted'])) && (intval($location['deleted']))) {
					logger('deleting hubloc: ' . $r[0]['hubloc_addr']);
					$n = q("update hubloc set hubloc_deleted = 1, hubloc_updated = '%s' where hubloc_id = %d",
						dbesc(datetime_convert()),
						intval($r[0]['hubloc_id'])
					);
					$what .= 'delete_hub ';
					$changed = true;
				}
				continue;
			}

			// Existing hubs are dealt with. Now let's process any new ones.
			// New hub claiming to be primary. Make it so by removing any existing primaries.

			if(intval($location['primary'])) {
				$r = q("update hubloc set hubloc_primary = 0, hubloc_updated = '%s' where hubloc_hash = '%s' and hubloc_primary = 1",
					dbesc(datetime_convert()),
					dbesc($sender['hash'])
				);
			}
			logger('New hub: ' . $location['url']);

			$r = hubloc_store_lowlevel(
				[
					'hubloc_guid'      => $sender['guid'],
					'hubloc_guid_sig'  => $sender['guid_sig'],
					'hubloc_hash'      => $sender['hash'],
					'hubloc_addr'      => $location['address'],
					'hubloc_network'   => 'zot',
					'hubloc_primary'   => intval($location['primary']),
					'hubloc_url'       => $location['url'],
					'hubloc_url_sig'   => $location['url_sig'],
					'hubloc_host'      => $location['host'],
					'hubloc_callback'  => $location['callback'],
					'hubloc_sitekey'   => $location['sitekey'],
					'hubloc_updated'   => datetime_convert(),
					'hubloc_connected' => datetime_convert()
				]
			);

			$what .= 'newhub ';
			$changed = true;

			if($location['primary']) {
				$r = q("select * from hubloc where hubloc_addr = '%s' and hubloc_sitekey = '%s' limit 1",
					dbesc($location['address']),
					dbesc($location['sitekey'])
				);
				if($r)
					hubloc_change_primary($r[0]);
			}
		}

		// get rid of any hubs we have for this channel which weren't reported.

		if($absolute && $xisting) {
			foreach($xisting as $x) {
				if(! array_key_exists('updated',$x)) {
					logger('Deleting unreferenced hub location ' . $x['hubloc_addr']);
					$r = q("update hubloc set hubloc_deleted = 1, hubloc_updated = '%s' where hubloc_id = %d",
						dbesc(datetime_convert()),
						intval($x['hubloc_id'])
					);
					$what .= 'removed_hub ';
					$changed = true;
				}
			}
		}
	}
	else {
		logger('No locations to sync!');
	}

	$ret['change_message'] = $what;
	$ret['changed'] = $changed;

	return $ret;
}

/**
 * @brief Returns an array with all known distinct hubs for this channel.
 *
 * @see zot_get_hublocs()
 * @param array $channel an associative array which must contain
 *  * \e string \b channel_hash the hash of the channel
 * @return array an array with associative arrays
 */
function zot_encode_locations($channel) {
	$ret = array();

	$x = zot_get_hublocs($channel['channel_hash']);

	if($x && count($x)) {
		foreach($x as $hub) {

			// if this is a local channel that has been deleted, the hubloc is no good - make sure it is marked deleted
			// so that nobody tries to use it.

			if(intval($channel['channel_removed']) && $hub['hubloc_url'] === z_root())
				$hub['hubloc_deleted'] = 1;

			$ret[] = [
				'host'     => $hub['hubloc_host'],
				'address'  => $hub['hubloc_addr'],
				'primary'  => (intval($hub['hubloc_primary']) ? true : false),
				'url'      => $hub['hubloc_url'],
				'url_sig'  => $hub['hubloc_url_sig'],
				'callback' => $hub['hubloc_callback'],
				'sitekey'  => $hub['hubloc_sitekey'],
				'deleted'  => (intval($hub['hubloc_deleted']) ? true : false)
			];
		}
	}

	return $ret;
}

/**
 * @brief Imports a directory profile.
 *
 * @param string $hash
 * @param array $profile
 * @param string $addr
 * @param number $ud_flags (optional) UPDATE_FLAGS_UPDATED
 * @param number $suppress_update (optional) default 0
 * @return boolean $updated if something changed
 */
function import_directory_profile($hash, $profile, $addr, $ud_flags = UPDATE_FLAGS_UPDATED, $suppress_update = 0) {

	logger('import_directory_profile', LOGGER_DEBUG);
	if (! $hash)
		return false;

	$arr = array();

	$arr['xprof_hash']         = $hash;
	$arr['xprof_dob']          = (($profile['birthday'] === '0000-00-00') ? $profile['birthday'] : datetime_convert('','',$profile['birthday'],'Y-m-d')); // !!!! check this for 0000 year
	$arr['xprof_age']          = (($profile['age'])         ? intval($profile['age']) : 0);
	$arr['xprof_desc']         = (($profile['description']) ? htmlspecialchars($profile['description'], ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_gender']       = (($profile['gender'])      ? htmlspecialchars($profile['gender'],      ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_marital']      = (($profile['marital'])     ? htmlspecialchars($profile['marital'],     ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_sexual']       = (($profile['sexual'])      ? htmlspecialchars($profile['sexual'],      ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_locale']       = (($profile['locale'])      ? htmlspecialchars($profile['locale'],      ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_region']       = (($profile['region'])      ? htmlspecialchars($profile['region'],      ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_postcode']     = (($profile['postcode'])    ? htmlspecialchars($profile['postcode'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_country']      = (($profile['country'])     ? htmlspecialchars($profile['country'],     ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_about']        = (($profile['about'])       ? htmlspecialchars($profile['about'],       ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_homepage']     = (($profile['homepage'])    ? htmlspecialchars($profile['homepage'],    ENT_COMPAT,'UTF-8',false) : '');
	$arr['xprof_hometown']     = (($profile['hometown'])    ? htmlspecialchars($profile['hometown'],    ENT_COMPAT,'UTF-8',false) : '');

	$clean = array();
	if (array_key_exists('keywords', $profile) and is_array($profile['keywords'])) {
		import_directory_keywords($hash,$profile['keywords']);
		foreach ($profile['keywords'] as $kw) {
			$kw = trim(htmlspecialchars($kw,ENT_COMPAT, 'UTF-8', false));
			$kw = trim($kw, ',');
			$clean[] = $kw;
		}
	}

	$arr['xprof_keywords'] = implode(' ',$clean);

	// Self censored, make it so
	// These are not translated, so the German "erwachsenen" keyword will not censor the directory profile. Only the English form - "adult".


	if(in_arrayi('nsfw',$clean) || in_arrayi('adult',$clean)) {
		q("update xchan set xchan_selfcensored = 1 where xchan_hash = '%s'",
			dbesc($hash)
		);
	}

	$r = q("select * from xprof where xprof_hash = '%s' limit 1",
		dbesc($hash)
	);

	if ($arr['xprof_age'] > 150)
		$arr['xprof_age'] = 150;
	if ($arr['xprof_age'] < 0)
		$arr['xprof_age'] = 0;

	if ($r) {
		$update = false;
		foreach ($r[0] as $k => $v) {
			if ((array_key_exists($k,$arr)) && ($arr[$k] != $v)) {
				logger('import_directory_profile: update ' . $k . ' => ' . $arr[$k]);
				$update = true;
				break;
			}
		}
		if ($update) {
			q("update xprof set
				xprof_desc = '%s',
				xprof_dob = '%s',
				xprof_age = %d,
				xprof_gender = '%s',
				xprof_marital = '%s',
				xprof_sexual = '%s',
				xprof_locale = '%s',
				xprof_region = '%s',
				xprof_postcode = '%s',
				xprof_country = '%s',
				xprof_about = '%s',
				xprof_homepage = '%s',
				xprof_hometown = '%s',
				xprof_keywords = '%s'
				where xprof_hash = '%s'",
				dbesc($arr['xprof_desc']),
				dbesc($arr['xprof_dob']),
				intval($arr['xprof_age']),
				dbesc($arr['xprof_gender']),
				dbesc($arr['xprof_marital']),
				dbesc($arr['xprof_sexual']),
				dbesc($arr['xprof_locale']),
				dbesc($arr['xprof_region']),
				dbesc($arr['xprof_postcode']),
				dbesc($arr['xprof_country']),
				dbesc($arr['xprof_about']),
				dbesc($arr['xprof_homepage']),
				dbesc($arr['xprof_hometown']),
				dbesc($arr['xprof_keywords']),
				dbesc($arr['xprof_hash'])
			);
		}
	} else {
		$update = true;
		logger('New profile');
		q("insert into xprof (xprof_hash, xprof_desc, xprof_dob, xprof_age, xprof_gender, xprof_marital, xprof_sexual, xprof_locale, xprof_region, xprof_postcode, xprof_country, xprof_about, xprof_homepage, xprof_hometown, xprof_keywords) values ('%s', '%s', '%s', %d, '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s') ",
			dbesc($arr['xprof_hash']),
			dbesc($arr['xprof_desc']),
			dbesc($arr['xprof_dob']),
			intval($arr['xprof_age']),
			dbesc($arr['xprof_gender']),
			dbesc($arr['xprof_marital']),
			dbesc($arr['xprof_sexual']),
			dbesc($arr['xprof_locale']),
			dbesc($arr['xprof_region']),
			dbesc($arr['xprof_postcode']),
			dbesc($arr['xprof_country']),
			dbesc($arr['xprof_about']),
			dbesc($arr['xprof_homepage']),
			dbesc($arr['xprof_hometown']),
			dbesc($arr['xprof_keywords'])
		);
	}

	$d = [
			'xprof' => $arr,
			'profile' => $profile,
			'update' => $update
	];
	/**
	 * @hooks import_directory_profile
	 *   Called when processing delivery of a profile structure from an external source (usually for directory storage).
	 *   * \e array \b xprof
	 *   * \e array \b profile
	 *   * \e boolean \b update
	 */
	call_hooks('import_directory_profile', $d);

	if (($d['update']) && (! $suppress_update))
		update_modtime($arr['xprof_hash'],random_string() . '@' . App::get_hostname(), $addr, $ud_flags);

	return $d['update'];
}

/**
 * @brief
 *
 * @param string $hash An xtag_hash
 * @param array $keywords
 */
function import_directory_keywords($hash, $keywords) {

	$existing = array();
	$r = q("select * from xtag where xtag_hash = '%s' and xtag_flags = 0",
		dbesc($hash)
	);

	if($r) {
		foreach($r as $rr)
			$existing[] = $rr['xtag_term'];
	}

	$clean = array();
	foreach($keywords as $kw) {
		$kw = trim(htmlspecialchars($kw,ENT_COMPAT, 'UTF-8', false));
		$kw = trim($kw, ',');
		$clean[] = $kw;
	}

	foreach($existing as $x) {
		if(! in_array($x, $clean))
			$r = q("delete from xtag where xtag_hash = '%s' and xtag_term = '%s' and xtag_flags = 0",
				dbesc($hash),
				dbesc($x)
			);
	}
	foreach($clean as $x) {
		if(! in_array($x, $existing)) {
			$r = q("insert into xtag ( xtag_hash, xtag_term, xtag_flags) values ( '%s' ,'%s', 0 )",
				dbesc($hash),
				dbesc($x)
			);
		}
	}
}

/**
 * @brief
 *
 * @param string $hash
 * @param string $guid
 * @param string $addr
 * @param int $flags (optional) default 0
 */
function update_modtime($hash, $guid, $addr, $flags = 0) {

	$dirmode = intval(get_config('system', 'directory_mode'));

	if($dirmode == DIRECTORY_MODE_NORMAL)
		return;

	if($flags) {
		q("insert into updates (ud_hash, ud_guid, ud_date, ud_flags, ud_addr ) values ( '%s', '%s', '%s', %d, '%s' )",
			dbesc($hash),
			dbesc($guid),
			dbesc(datetime_convert()),
			intval($flags),
			dbesc($addr)
		);
	}
	else {
		q("update updates set ud_flags = ( ud_flags | %d ) where ud_addr = '%s' and not (ud_flags & %d)>0 ",
			intval(UPDATE_FLAGS_UPDATED),
			dbesc($addr),
			intval(UPDATE_FLAGS_UPDATED)
		);
	}
}

/**
 * @brief
 *
 * @param array $arr
 * @param string $pubkey
 * @return boolean true if updated or inserted
 */
function import_site($arr, $pubkey) {
	if( (! is_array($arr)) || (! $arr['url']) || (! $arr['url_sig']))
		return false;

	if(! rsa_verify($arr['url'], base64url_decode($arr['url_sig']), $pubkey)) {
		logger('Bad url_sig');
		return false;
	}

	$update = false;
	$exists = false;

	$r = q("select * from site where site_url = '%s' limit 1",
		dbesc($arr['url'])
	);
	if($r) {
		$exists = true;
		$siterecord = $r[0];
	}

	$site_directory = 0;
	if($arr['directory_mode'] == 'normal')
		$site_directory = DIRECTORY_MODE_NORMAL;
	if($arr['directory_mode'] == 'primary')
		$site_directory = DIRECTORY_MODE_PRIMARY;
	if($arr['directory_mode'] == 'secondary')
		$site_directory = DIRECTORY_MODE_SECONDARY;
	if($arr['directory_mode'] == 'standalone')
		$site_directory = DIRECTORY_MODE_STANDALONE;

	$register_policy = 0;
	if($arr['register_policy'] == 'closed')
		$register_policy = REGISTER_CLOSED;
	if($arr['register_policy'] == 'open')
		$register_policy = REGISTER_OPEN;
	if($arr['register_policy'] == 'approve')
		$register_policy = REGISTER_APPROVE;

	$access_policy = 0;
	if(array_key_exists('access_policy',$arr)) {
		if($arr['access_policy'] === 'private')
			$access_policy = ACCESS_PRIVATE;
		if($arr['access_policy'] === 'paid')
			$access_policy = ACCESS_PAID;
		if($arr['access_policy'] === 'free')
			$access_policy = ACCESS_FREE;
		if($arr['access_policy'] === 'tiered')
			$access_policy = ACCESS_TIERED;
	}

	// don't let insecure sites register as public hubs

	if(strpos($arr['url'],'https://') === false)
		$access_policy = ACCESS_PRIVATE;

	if($access_policy != ACCESS_PRIVATE) {
		$x = z_fetch_url($arr['url'] . '/siteinfo.json');
		if(! $x['success'])
			$access_policy = ACCESS_PRIVATE;
	}

	$directory_url = htmlspecialchars($arr['directory_url'],ENT_COMPAT,'UTF-8',false);
	$url = htmlspecialchars(strtolower($arr['url']),ENT_COMPAT,'UTF-8',false);
	$sellpage = htmlspecialchars($arr['sellpage'],ENT_COMPAT,'UTF-8',false);
	$site_location = htmlspecialchars($arr['location'],ENT_COMPAT,'UTF-8',false);
	$site_realm = htmlspecialchars($arr['realm'],ENT_COMPAT,'UTF-8',false);
	$site_project = htmlspecialchars($arr['project'],ENT_COMPAT,'UTF-8',false);
	$site_crypto = ((array_key_exists('encryption',$arr) && is_array($arr['encryption'])) ? htmlspecialchars(implode(',',$arr['encryption']),ENT_COMPAT,'UTF-8',false) : '');
	$site_version = ((array_key_exists('version',$arr)) ? htmlspecialchars($arr['version'],ENT_COMPAT,'UTF-8',false) : '');

	// You can have one and only one primary directory per realm.
	// Downgrade any others claiming to be primary. As they have
	// flubbed up this badly already, don't let them be directory servers at all.

	if(($site_directory === DIRECTORY_MODE_PRIMARY)
			&& ($site_realm === get_directory_realm())
			&& ($arr['url'] != get_directory_primary())) {
		$site_directory = DIRECTORY_MODE_NORMAL;
	}

	$site_flags = $site_directory;

	if(array_key_exists('zot',$arr)) {
		set_sconfig($arr['url'],'system','zot_version',$arr['zot']);
	}

	if($exists) {
		if(($siterecord['site_flags'] != $site_flags)
			|| ($siterecord['site_access'] != $access_policy)
			|| ($siterecord['site_directory'] != $directory_url)
			|| ($siterecord['site_sellpage'] != $sellpage)
			|| ($siterecord['site_location'] != $site_location)
			|| ($siterecord['site_register'] != $register_policy)
			|| ($siterecord['site_project'] != $site_project)
			|| ($siterecord['site_realm'] != $site_realm)
			|| ($siterecord['site_crypto'] != $site_crypto)
			|| ($siterecord['site_version'] != $site_version)   ) {

			$update = true;

//			logger('import_site: input: ' . print_r($arr,true));
//			logger('import_site: stored: ' . print_r($siterecord,true));

			$r = q("update site set site_dead = 0, site_location = '%s', site_flags = %d, site_access = %d, site_directory = '%s', site_register = %d, site_update = '%s', site_sellpage = '%s', site_realm = '%s', site_type = %d, site_project = '%s', site_version = '%s', site_crypto = '%s'
				where site_url = '%s'",
				dbesc($site_location),
				intval($site_flags),
				intval($access_policy),
				dbesc($directory_url),
				intval($register_policy),
				dbesc(datetime_convert()),
				dbesc($sellpage),
				dbesc($site_realm),
				intval(SITE_TYPE_ZOT),
				dbesc($site_project),
				dbesc($site_version),
				dbesc($site_crypto),
				dbesc($url)
			);
			if(! $r) {
				logger('Update failed. ' . print_r($arr,true));
			}
		}
		else {
			// update the timestamp to indicate we communicated with this site
			q("update site set site_dead = 0, site_update = '%s' where site_url = '%s'",
				dbesc(datetime_convert()),
				dbesc($url)
			);
		}
	}
	else {
		$update = true;

		$r = site_store_lowlevel(
			[
				'site_location'  => $site_location,
				'site_url'       => $url,
				'site_access'    => intval($access_policy),
				'site_flags'     => intval($site_flags),
				'site_update'    => datetime_convert(),
				'site_directory' => $directory_url,
				'site_register'  => intval($register_policy),
				'site_sellpage'  => $sellpage,
				'site_realm'     => $site_realm,
				'site_type'      => intval(SITE_TYPE_ZOT),
				'site_project'   => $site_project,
				'site_version'   => $site_version,
				'site_crypto'    => $site_crypto
			]
		);

		if(! $r) {
			logger('Record create failed. ' . print_r($arr,true));
		}
	}

	return $update;
}


/**
 * @brief Builds and sends a sync packet.
 *
 * Send a zot packet to all hubs where this channel is duplicated, refreshing
 * such things as personal settings, channel permissions, address book updates, etc.
 *
 * @param int $uid (optional) default 0
 * @param array $packet (optional) default null
 * @param boolean $groups_changed (optional) default false
 */
function build_sync_packet($uid = 0, $packet = null, $groups_changed = false) {

	logger('build_sync_packet');

	$keychange = (($packet && array_key_exists('keychange',$packet)) ? true : false);
	if($keychange) {
		logger('keychange sync');
	}

	if(! $uid)
		$uid = local_channel();

	if(! $uid)
		return;

	$r = q("select * from channel where channel_id = %d limit 1",
		intval($uid)
	);
	if(! $r)
		return;

	$channel = $r[0];

	// don't provide these in the export 

	unset($channel['channel_active']);
	unset($channel['channel_password']);
	unset($channel['channel_salt']);

	translate_channel_perms_outbound($channel);
	if($packet && array_key_exists('abook',$packet) && $packet['abook']) {
		for($x = 0; $x < count($packet['abook']); $x ++) {
			translate_abook_perms_outbound($packet['abook'][$x]);
		}
	}

	if(intval($channel['channel_removed']))
		return;

	$h = q("select hubloc.*, site.site_crypto from hubloc left join site on site_url = hubloc_url where hubloc_hash = '%s' and hubloc_deleted = 0",
		dbesc(($keychange) ? $packet['keychange']['old_hash'] : $channel['channel_hash'])
	);

	if(! $h)
		return;

	$synchubs = array();

	foreach($h as $x) {
		if($x['hubloc_host'] == App::get_hostname())
			continue;

		$y = q("select site_dead from site where site_url = '%s' limit 1",
			dbesc($x['hubloc_url'])
		);

		if((! $y) || ($y[0]['site_dead'] == 0))
			$synchubs[] = $x;
	}

	if(! $synchubs)
		return;

	$r = q("select xchan_guid, xchan_guid_sig from xchan where xchan_hash  = '%s' limit 1",
		dbesc($channel['channel_hash'])
	);
	if(! $r)
		return;

	$env_recips = array();
	$env_recips[] = array('guid' => $r[0]['xchan_guid'],'guid_sig' => $r[0]['xchan_guid_sig']);

	if($packet)
		logger('packet: ' . print_r($packet, true),LOGGER_DATA, LOG_DEBUG);

	$info = (($packet) ? $packet : array());
	$info['type'] = 'channel_sync';
	$info['encoding'] = 'red'; // note: not zot, this packet is very platform specific
	$info['relocate'] = ['channel_address' => $channel['channel_address'], 'url' => z_root() ];

	if(array_key_exists($uid,App::$config) && array_key_exists('transient',App::$config[$uid])) {
		$settings = App::$config[$uid]['transient'];
		if($settings) {
			$info['config'] = $settings;
		}
	}

	if($channel) {
		$info['channel'] = array();
		foreach($channel as $k => $v) {

			// filter out any joined tables like xchan

			if(strpos($k,'channel_') !== 0)
				continue;

			// don't pass these elements, they should not be synchronised


			$disallowed = [
				'channel_id','channel_account_id','channel_primary','channel_address',
				'channel_deleted','channel_removed','channel_system'
			];

			if(! $keychange) {
				$disallowed[] = 'channel_prvkey';
			}

			if(in_array($k,$disallowed))
				continue;

			$info['channel'][$k] = $v;
		}
	}

	if($groups_changed) {
		$r = q("select hash as collection, visible, deleted, gname as name from groups where uid = %d",
			intval($uid)
		);
		if($r)
			$info['collections'] = $r;

		$r = q("select groups.hash as collection, group_member.xchan as member from groups left join group_member on groups.id = group_member.gid where group_member.uid = %d",
			intval($uid)
		);
		if($r)
			$info['collection_members'] = $r;
	}

	$interval = ((get_config('system','delivery_interval') !== false)
			? intval(get_config('system','delivery_interval')) : 2 );

	logger('Packet: ' . print_r($info,true), LOGGER_DATA, LOG_DEBUG);

	$total = count($synchubs);

	foreach($synchubs as $hub) {
		$hash = random_string();
		$n = zot_build_packet($channel,'notify',$env_recips,$hub['hubloc_sitekey'],$hub['site_crypto'],$hash);
		queue_insert(array(
			'hash'       => $hash,
			'account_id' => $channel['channel_account_id'],
			'channel_id' => $channel['channel_id'],
			'posturl'    => $hub['hubloc_callback'],
			'notify'     => $n,
			'msg'        => json_encode($info)
		));


		$x = q("select count(outq_hash) as total from outq where outq_delivered = 0");
		if(intval($x[0]['total']) > intval(get_config('system','force_queue_threshold',300))) {
			logger('immediate delivery deferred.', LOGGER_DEBUG, LOG_INFO);
			update_queue_item($hash);
			continue;
		}


		Zotlabs\Daemon\Master::Summon(array('Deliver', $hash));
		$total = $total - 1;

		if($interval && $total)
			@time_sleep_until(microtime(true) + (float) $interval);
	}
}

/**
 * @brief
 *
 * @param array $sender
 * @param array $arr
 * @param array $deliveries
 * @return array
 */
function process_channel_sync_delivery($sender, $arr, $deliveries) {

	require_once('include/import.php');

	/** @FIXME this will sync red structures (channel, pconfig and abook).
		Eventually we need to make this application agnostic. */

	$result = [];

	$keychange = ((array_key_exists('keychange',$arr)) ? true : false);

	foreach ($deliveries as $d) {
		$r = q("select * from channel where channel_hash = '%s' limit 1",
			dbesc(($keychange) ? $arr['keychange']['old_hash'] : $d['hash'])
		);

		if (! $r) {
			$result[] = array($d['hash'],'not found');
			continue;
		}

		$channel = $r[0];

		$max_friends = service_class_fetch($channel['channel_id'],'total_channels');
		$max_feeds = account_service_class_fetch($channel['channel_account_id'],'total_feeds');

		if($channel['channel_hash'] != $sender['hash']) {
			logger('Possible forgery. Sender ' . $sender['hash'] . ' is not ' . $channel['channel_hash']);
			$result[] = array($d['hash'],'channel mismatch',$channel['channel_name'],'');
			continue;
		}

		if($keychange) {
			// verify the keychange operation
			if(! rsa_verify($arr['channel']['channel_pubkey'],base64url_decode($arr['keychange']['new_sig']),$channel['channel_prvkey'])) {
				logger('sync keychange: verification failed');
				continue;
			}

			$sig = base64url_encode(rsa_sign($channel['channel_guid'],$arr['channel']['channel_prvkey']));
			$hash = make_xchan_hash($channel['channel_guid'],$sig);


			$r = q("update channel set channel_prvkey = '%s', channel_pubkey = '%s', channel_guid_sig = '%s',
				channel_hash = '%s' where channel_id = %d",
				dbesc($arr['channel']['channel_prvkey']),
				dbesc($arr['channel']['channel_pubkey']),
				dbesc($sig),
				dbesc($hash),
				intval($channel['channel_id'])
			);
			if(! $r) {
				logger('keychange sync: channel update failed');
				continue;
 			}

			$r = q("select * from channel where channel_id = %d",
				intval($channel['channel_id'])
			);

			if(! $r) {
				logger('keychange sync: channel retrieve failed');
				continue;
			}

			$channel = $r[0];

			$h = q("select * from hubloc where hubloc_hash = '%s' and hubloc_url = '%s' ",
				dbesc($arr['keychange']['old_hash']),
				dbesc(z_root())
			);

			if($h) {
				foreach($h as $hv) {
					$hv['hubloc_guid_sig'] = $sig;
					$hv['hubloc_hash']     = $hash;
					$hv['hubloc_url_sig']  = base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey']));
					hubloc_store_lowlevel($hv);
				}
			}

			$x = q("select * from xchan where xchan_hash = '%s' ",
				dbesc($arr['keychange']['old_hash'])
			);

			$check = q("select * from xchan where xchan_hash = '%s'",
				dbesc($hash)
			);

			if(($x) && (! $check)) {
				$oldxchan = $x[0];
				foreach($x as $xv) {
					$xv['xchan_guid_sig']  = $sig;
					$xv['xchan_hash']      = $hash;
					$xv['xchan_pubkey']    = $channel['channel_pubkey'];
					xchan_store_lowlevel($xv);
					$newxchan = $xv;
				}
			}

			$a = q("select * from abook where abook_xchan = '%s' and abook_self = 1",
				dbesc($arr['keychange']['old_hash'])
			);

			if($a) {
				q("update abook set abook_xchan = '%s' where abook_id = %d",
					dbesc($hash),
					intval($a[0]['abook_id'])
				);
			}

			xchan_change_key($oldxchan,$newxchan,$arr['keychange']);

			// keychange operations can end up in a confused state if you try and sync anything else
			// besides the channel keys, so ignore any other packets.

			continue;
		}

		// if the clone is active, so are we

		if(substr($channel['channel_active'],0,10) !== substr(datetime_convert(),0,10)) {
			q("UPDATE channel set channel_active = '%s' where channel_id = %d",
				dbesc(datetime_convert()),
				intval($channel['channel_id'])
			);
		}

		if(array_key_exists('config',$arr) && is_array($arr['config']) && count($arr['config'])) {
			foreach($arr['config'] as $cat => $k) {
				foreach($arr['config'][$cat] as $k => $v)
					set_pconfig($channel['channel_id'],$cat,$k,$v);
			}
		}

		if(array_key_exists('obj',$arr) && $arr['obj'])
			sync_objs($channel,$arr['obj']);

		if(array_key_exists('likes',$arr) && $arr['likes'])
			import_likes($channel,$arr['likes']);

		if(array_key_exists('app',$arr) && $arr['app'])
			sync_apps($channel,$arr['app']);

		if(array_key_exists('chatroom',$arr) && $arr['chatroom'])
			sync_chatrooms($channel,$arr['chatroom']);

		if(array_key_exists('conv',$arr) && $arr['conv'])
			import_conv($channel,$arr['conv']);

		if(array_key_exists('mail',$arr) && $arr['mail'])
			sync_mail($channel,$arr['mail']);

		if(array_key_exists('event',$arr) && $arr['event'])
			sync_events($channel,$arr['event']);

		if(array_key_exists('event_item',$arr) && $arr['event_item'])
			sync_items($channel,$arr['event_item'],((array_key_exists('relocate',$arr)) ? $arr['relocate'] : null));

		if(array_key_exists('item',$arr) && $arr['item'])
			sync_items($channel,$arr['item'],((array_key_exists('relocate',$arr)) ? $arr['relocate'] : null));

		// deprecated, maintaining for a few months for upward compatibility
		// this should sync webpages, but the logic is a bit subtle

		if(array_key_exists('item_id',$arr) && $arr['item_id'])
			sync_items($channel,$arr['item_id']);

		if(array_key_exists('menu',$arr) && $arr['menu'])
			sync_menus($channel,$arr['menu']);

		if(array_key_exists('file',$arr) && $arr['file'])
			sync_files($channel,$arr['file']);

		if(array_key_exists('wiki',$arr) && $arr['wiki'])
			sync_items($channel,$arr['wiki'],((array_key_exists('relocate',$arr)) ? $arr['relocate'] : null));

		if(array_key_exists('channel',$arr) && is_array($arr['channel']) && count($arr['channel'])) {

			$remote_channel = $arr['channel'];
			$remote_channel['channel_id'] = $channel['channel_id'];
			translate_channel_perms_inbound($remote_channel);


			if(array_key_exists('channel_pageflags',$arr['channel']) && intval($arr['channel']['channel_pageflags'])) {
				// Several pageflags are site-specific and cannot be sync'd.
				// Only allow those bits which are shareable from the remote and then 
				// logically OR with the local flags

				$arr['channel']['channel_pageflags'] = $arr['channel']['channel_pageflags'] & (PAGE_HIDDEN|PAGE_AUTOCONNECT|PAGE_APPLICATION|PAGE_PREMIUM|PAGE_ADULT);
				$arr['channel']['channel_pageflags'] = $arr['channel']['channel_pageflags'] | $channel['channel_pageflags'];
			}

			$disallowed = [
				'channel_id',        'channel_account_id',  'channel_primary',   'channel_prvkey',
				'channel_address',   'channel_notifyflags', 'channel_removed',   'channel_deleted',
				'channel_system',    'channel_r_stream',    'channel_r_profile', 'channel_r_abook',
				'channel_r_storage', 'channel_r_pages',     'channel_w_stream',  'channel_w_wall',
				'channel_w_comment', 'channel_w_mail',      'channel_w_like',    'channel_w_tagwall',
				'channel_w_chat',    'channel_w_storage',   'channel_w_pages',   'channel_a_republish',
				'channel_a_delegate'
			];

			$clean = array();
			foreach($arr['channel'] as $k => $v) {
				if(in_array($k,$disallowed))
					continue;
				$clean[$k] = $v;
			}
			if(count($clean)) {
				foreach($clean as $k => $v) {
					$r = dbq("UPDATE channel set " . dbesc($k) . " = '" . dbesc($v)
						. "' where channel_id = " . intval($channel['channel_id']) );
				}
			}
		}

		if(array_key_exists('abook',$arr) && is_array($arr['abook']) && count($arr['abook'])) {
			$total_friends = 0;
			$total_feeds = 0;

			$r = q("select abook_id, abook_feed from abook where abook_channel = %d",
				intval($channel['channel_id'])
			);
			if($r) {
				// don't count yourself
				$total_friends = ((count($r) > 0) ? count($r) - 1 : 0);
				foreach($r as $rr)
					if(intval($rr['abook_feed']))
						$total_feeds ++;
			}


			$disallowed = array('abook_id','abook_account','abook_channel','abook_rating','abook_rating_text','abook_not_here');

			foreach($arr['abook'] as $abook) {

				$abconfig = null;

				if(array_key_exists('abconfig',$abook) && is_array($abook['abconfig']) && count($abook['abconfig']))
					$abconfig = $abook['abconfig'];

				if(! array_key_exists('abook_blocked',$abook)) {
					// convert from redmatrix
					$abook['abook_blocked']     = (($abook['abook_flags'] & 0x0001) ? 1 : 0);
					$abook['abook_ignored']     = (($abook['abook_flags'] & 0x0002) ? 1 : 0);
					$abook['abook_hidden']      = (($abook['abook_flags'] & 0x0004) ? 1 : 0);
					$abook['abook_archived']    = (($abook['abook_flags'] & 0x0008) ? 1 : 0);
					$abook['abook_pending']     = (($abook['abook_flags'] & 0x0010) ? 1 : 0);
					$abook['abook_unconnected'] = (($abook['abook_flags'] & 0x0020) ? 1 : 0);
					$abook['abook_self']        = (($abook['abook_flags'] & 0x0080) ? 1 : 0);
					$abook['abook_feed']        = (($abook['abook_flags'] & 0x0100) ? 1 : 0);
				}

				$clean = array();
				if($abook['abook_xchan'] && $abook['entry_deleted']) {
					logger('Removing abook entry for ' . $abook['abook_xchan']);

					$r = q("select abook_id, abook_feed from abook where abook_xchan = '%s' and abook_channel = %d and abook_self = 0 limit 1",
						dbesc($abook['abook_xchan']),
						intval($channel['channel_id'])
					);
					if($r) {
						contact_remove($channel['channel_id'],$r[0]['abook_id']);
						if($total_friends)
							$total_friends --;
						if(intval($r[0]['abook_feed']))
							$total_feeds --;
					}
					continue;
				}

				// Perform discovery if the referenced xchan hasn't ever been seen on this hub.
				// This relies on the undocumented behaviour that red sites send xchan info with the abook
				// and import_author_xchan will look them up on all federated networks

				if($abook['abook_xchan'] && $abook['xchan_addr']) {
					$h = zot_get_hublocs($abook['abook_xchan']);
					if(! $h) {
						$xhash = import_author_xchan(encode_item_xchan($abook));
						if(! $xhash) {
							logger('Import of ' . $abook['xchan_addr'] . ' failed.');
							continue;
						}
					}
				}

				foreach($abook as $k => $v) {
					if(in_array($k,$disallowed) || (strpos($k,'abook') !== 0))
						continue;
					$clean[$k] = $v;
				}

				if(! array_key_exists('abook_xchan',$clean))
					continue;

				if(array_key_exists('abook_instance',$clean) && $clean['abook_instance'] && strpos($clean['abook_instance'],z_root()) === false) {
					$clean['abook_not_here'] = 1;
				}


				$r = q("select * from abook where abook_xchan = '%s' and abook_channel = %d limit 1",
					dbesc($clean['abook_xchan']),
					intval($channel['channel_id'])
				);

				// make sure we have an abook entry for this xchan on this system

				if(! $r) {
					if($max_friends !== false && $total_friends > $max_friends) {
						logger('total_channels service class limit exceeded');
						continue;
					}
					if($max_feeds !== false && intval($clean['abook_feed']) && $total_feeds > $max_feeds) {
						logger('total_feeds service class limit exceeded');
						continue;
					}
					abook_store_lowlevel(
						[
							'abook_xchan'   => $clean['abook_xchan'],
							'abook_account' => $channel['channel_account_id'],
							'abook_channel' => $channel['channel_id']
						]
					);
					$total_friends ++;
					if(intval($clean['abook_feed']))
						$total_feeds ++;
				}

				if(count($clean)) {
					foreach($clean as $k => $v) {
						if($k == 'abook_dob')
							$v = dbescdate($v);

						$r = dbq("UPDATE abook set " . dbesc($k) . " = '" . dbesc($v)
						. "' where abook_xchan = '" . dbesc($clean['abook_xchan']) . "' and abook_channel = " . intval($channel['channel_id']));
					}
				}

				// This will set abconfig vars if the sender is using old-style fixed permissions
				// using the raw abook record as passed to us. New-style permissions will fall through
				// and be set using abconfig

				translate_abook_perms_inbound($channel,$abook);

				if($abconfig) {
					/// @fixme does not handle sync of del_abconfig
					foreach($abconfig as $abc) {
						set_abconfig($channel['channel_id'],$abc['xchan'],$abc['cat'],$abc['k'],$abc['v']);
					}
				}
			}
		}

		// sync collections (privacy groups) oh joy...

		if(array_key_exists('collections',$arr) && is_array($arr['collections']) && count($arr['collections'])) {
			$x = q("select * from groups where uid = %d",
				intval($channel['channel_id'])
			);
			foreach($arr['collections'] as $cl) {
				$found = false;
				if($x) {
					foreach($x as $y) {
						if($cl['collection'] == $y['hash']) {
							$found = true;
							break;
						}
					}
					if($found) {
						if(($y['gname'] != $cl['name'])
							|| ($y['visible'] != $cl['visible'])
							|| ($y['deleted'] != $cl['deleted'])) {
							q("update groups set gname = '%s', visible = %d, deleted = %d where hash = '%s' and uid = %d",
								dbesc($cl['name']),
								intval($cl['visible']),
								intval($cl['deleted']),
								dbesc($cl['collection']),
								intval($channel['channel_id'])
							);
						}
						if(intval($cl['deleted']) && (! intval($y['deleted']))) {
							q("delete from group_member where gid = %d",
								intval($y['id'])
							);
						}
					}
				}
				if(! $found) {
					$r = q("INSERT INTO groups ( hash, uid, visible, deleted, gname )
						VALUES( '%s', %d, %d, %d, '%s' ) ",
						dbesc($cl['collection']),
						intval($channel['channel_id']),
						intval($cl['visible']),
						intval($cl['deleted']),
						dbesc($cl['name'])
					);
				}

				// now look for any collections locally which weren't in the list we just received.
				// They need to be removed by marking deleted and removing the members.
				// This shouldn't happen except for clones created before this function was written.

				if($x) {
					$found_local = false;
					foreach($x as $y) {
						foreach($arr['collections'] as $cl) {
							if($cl['collection'] == $y['hash']) {
								$found_local = true;
								break;
							}
						}
						if(! $found_local) {
							q("delete from group_member where gid = %d",
								intval($y['id'])
							);
							q("update groups set deleted = 1 where id = %d and uid = %d",
								intval($y['id']),
								intval($channel['channel_id'])
							);
						}
					}
				}
			}

			// reload the group list with any updates
			$x = q("select * from groups where uid = %d",
				intval($channel['channel_id'])
			);

			// now sync the members

			if(array_key_exists('collection_members', $arr)
					&& is_array($arr['collection_members'])
					&& count($arr['collection_members'])) {

				// first sort into groups keyed by the group hash
				$members = array();
				foreach($arr['collection_members'] as $cm) {
					if(! array_key_exists($cm['collection'],$members))
						$members[$cm['collection']] = array();

					$members[$cm['collection']][] = $cm['member'];
				}

				// our group list is already synchronised
				if($x) {
					foreach($x as $y) {

						// for each group, loop on members list we just received
						if(isset($y['hash']) && isset($members[$y['hash']])) {
							foreach($members[$y['hash']] as $member) {
								$found = false;
								$z = q("select xchan from group_member where gid = %d and uid = %d and xchan = '%s' limit 1",
									intval($y['id']),
									intval($channel['channel_id']),
									dbesc($member)
								);
								if($z)
									$found = true;

								// if somebody is in the group that wasn't before - add them

								if(! $found) {
									q("INSERT INTO group_member (uid, gid, xchan)
										VALUES( %d, %d, '%s' ) ",
										intval($channel['channel_id']),
										intval($y['id']),
										dbesc($member)
									);
								}
							}
						}

						// now retrieve a list of members we have on this site
						$m = q("select xchan from group_member where gid = %d and uid = %d",
							intval($y['id']),
							intval($channel['channel_id'])
						);
						if($m) {
							foreach($m as $mm) {
								// if the local existing member isn't in the list we just received - remove them
								if(! in_array($mm['xchan'],$members[$y['hash']])) {
									q("delete from group_member where xchan = '%s' and gid = %d and uid = %d",
										dbesc($mm['xchan']),
										intval($y['id']),
										intval($channel['channel_id'])
									);
								}
							}
						}
					}
				}
			}
		}

		if(array_key_exists('profile',$arr) && is_array($arr['profile']) && count($arr['profile'])) {

			$disallowed = array('id','aid','uid','guid');

			foreach($arr['profile'] as $profile) {

				$x = q("select * from profile where profile_guid = '%s' and uid = %d limit 1",
					dbesc($profile['profile_guid']),
					intval($channel['channel_id'])
				);
				if(! $x) {
					profile_store_lowlevel(
						[
							'aid'          => $channel['channel_account_id'],
							'uid'          => $channel['channel_id'],
							'profile_guid' => $profile['profile_guid'],
						]
					);

					$x = q("select * from profile where profile_guid = '%s' and uid = %d limit 1",
						dbesc($profile['profile_guid']),
						intval($channel['channel_id'])
					);
					if(! $x)
						continue;
				}
				$clean = array();
				foreach($profile as $k => $v) {
					if(in_array($k,$disallowed))
						continue;

					if($profile['is_default'] && in_array($k,['photo','thumb']))
						continue;

					if($k === 'name')
						$clean['fullname'] = $v;
					elseif($k === 'with')
						$clean['partner'] = $v;
					elseif($k === 'work')
						$clean['employment'] = $v;
					elseif(array_key_exists($k,$x[0]))
						$clean[$k] = $v;

					/**
					 * @TODO
					 * We also need to import local photos if a custom photo is selected
					 */

					if((strpos($profile['thumb'],'/photo/profile/l/') !== false) || intval($profile['is_default'])) {
						$profile['photo'] = z_root() . '/photo/profile/l/' . $channel['channel_id'];
						$profile['thumb'] = z_root() . '/photo/profile/m/' . $channel['channel_id'];
					}
					else {
						$profile['photo'] = z_root() . '/photo/' . basename($profile['photo']);
						$profile['thumb'] = z_root() . '/photo/' . basename($profile['thumb']);
					}
				}

				if(count($clean)) {
					foreach($clean as $k => $v) {
						$r = dbq("UPDATE profile set " . TQUOT . dbesc($k) . TQUOT . " = '" . dbesc($v)
						. "' where profile_guid = '" . dbesc($profile['profile_guid'])
						. "' and uid = " . intval($channel['channel_id']));
					}
				}
			}
		}

		$addon = ['channel' => $channel, 'data' => $arr];
		/**
		 * @hooks process_channel_sync_delivery
		 *   Called when accepting delivery of a 'sync packet' containing structure and table updates from a channel clone.
		 *   * \e array \b channel
		 *   * \e array \b data
		 */
		call_hooks('process_channel_sync_delivery', $addon);

		// we should probably do this for all items, but usually we only send one.

		if(array_key_exists('item',$arr) && is_array($arr['item'][0])) {
			$DR = new Zotlabs\Lib\DReport(z_root(),$d['hash'],$d['hash'],$arr['item'][0]['message_id'],'channel sync processed');
			$DR->addto_recipient($channel['channel_name'] . ' <' . channel_reddress($channel) . '>');
		}
		else
			$DR = new Zotlabs\Lib\DReport(z_root(),$d['hash'],$d['hash'],'sync packet','channel sync delivered');

		$result[] = $DR->get();
	}

	return $result;
}

/**
 * @brief Returns path to /rpost
 *
 * @todo We probably should make rpost discoverable.
 *
 * @param array $observer
 *   * \e string \b xchan_url
 * @return string
 */
function get_rpost_path($observer) {
	if(! $observer)
		return '';

	$parsed = parse_url($observer['xchan_url']);

	return $parsed['scheme'] . '://' . $parsed['host'] . (($parsed['port']) ? ':' . $parsed['port'] : '') . '/rpost?f=';
}

/**
 * @brief
 *
 * @param array $x
 * @return boolean|string return false or a hash
 */
function import_author_zot($x) {

	// Check that we have both a hubloc and xchan record - as occasionally storage calls will fail and
	// we may only end up with one; which results in posts with no author name or photo and are a bit
	// of a hassle to repair. If either or both are missing, do a full discovery probe.

	$hash = make_xchan_hash($x['guid'],$x['guid_sig']);

	// also - this function may get passed a profile url as 'url' and zot_refresh wants a hubloc_url (site baseurl),
	// so deconstruct the url (if we have one) and rebuild it with just the baseurl components.

	if(array_key_exists('url',$x)) {
		$m = parse_url($x['url']);
		$desturl = $m['scheme'] . '://' . $m['host'];
	}

	$r1 = q("select hubloc_url, hubloc_updated, site_dead from hubloc left join site on
		hubloc_url = site_url where hubloc_guid = '%s' and hubloc_guid_sig = '%s' and hubloc_primary = 1 limit 1",
		dbesc($x['guid']),
		dbesc($x['guid_sig'])
	);

	$r2 = q("select xchan_hash from xchan where xchan_guid = '%s' and xchan_guid_sig = '%s' limit 1",
		dbesc($x['guid']),
		dbesc($x['guid_sig'])
	);

	$site_dead = false;

	if($r1 && intval($r1[0]['site_dead'])) {
		$site_dead = true;
	}

	// We have valid and somewhat fresh information.

	if($r1 && $r2 && $r1[0]['hubloc_updated'] > datetime_convert('UTC','UTC','now - 1 week')) {
		logger('in cache', LOGGER_DEBUG);
		return $hash;
	}

	logger('not in cache or cache stale - probing: ' . print_r($x,true), LOGGER_DEBUG,LOG_INFO);

	// The primary hub may be dead. Try to find another one associated with this identity that is
	// still alive. If we find one, use that url for the discovery/refresh probe. Otherwise, the dead site
	// is all we have and there is no point probing it. Just return the hash indicating we have a
	// cached entry and the identity is valid. It's just unreachable until they bring back their
	// server from the grave or create another clone elsewhere.

	if($site_dead) {
		logger('dead site - ignoring', LOGGER_DEBUG,LOG_INFO);

		$r = q("select hubloc_url from hubloc left join site on hubloc_url = site_url
			where hubloc_hash = '%s' and site_dead = 0",
			dbesc($hash)
		);
		if($r) {
			logger('found another site that is not dead: ' . $r[0]['hubloc_url'], LOGGER_DEBUG,LOG_INFO);
			$desturl = $r[0]['hubloc_url'];
		}
		else {
			return $hash;
		}
	}


	$them = array('hubloc_url' => $desturl, 'xchan_guid' => $x['guid'], 'xchan_guid_sig' => $x['guid_sig']);
	if(zot_refresh($them))
		return $hash;

	return false;
}

/**
 * @brief Process a message request.
 *
 * If a site receives a comment to a post but finds they have no parent to attach it with, they
 * may send a 'request' packet containing the message_id of the missing parent. This is the handler
 * for that packet. We will create a message_list array of the entire conversation starting with
 * the missing parent and invoke delivery to the sender of the packet.
 *
 * include/deliver.php (for local delivery) and mod/post.php (for web delivery) detect the existence of
 * this 'message_list' at the destination and split it into individual messages which are
 * processed/delivered in order.
 *
 * Called from mod/post.php
 *
 * @param array $data
 * @return array
 */
function zot_reply_message_request($data) {
	$ret = array('success' => false);

	if (! $data['message_id']) {
		$ret['message'] = 'no message_id';
		logger('no message_id');
		json_return_and_die($ret);
	}

	$sender = $data['sender'];
	$sender_hash = make_xchan_hash($sender['guid'], $sender['guid_sig']);

	/*
	 * Find the local channel in charge of this post (the first and only recipient of the request packet)
	 */

	$arr = $data['recipients'][0];
	$recip_hash = make_xchan_hash($arr['guid'],$arr['guid_sig']);
	$c = q("select * from channel left join xchan on channel_hash = xchan_hash where channel_hash = '%s' limit 1",
		dbesc($recip_hash)
	);
	if (! $c) {
		logger('recipient channel not found.');
		$ret['message'] .= 'recipient not found.' . EOL;
		json_return_and_die($ret);
	}

	/*
	 * fetch the requested conversation
	 */

	$messages = zot_feed($c[0]['channel_id'],$sender_hash,array('message_id' => $data['message_id']));

	if ($messages) {
		$env_recips = null;

		$r = q("select hubloc.*, site.site_crypto from hubloc left join site on hubloc_url = site_url where hubloc_hash = '%s' and hubloc_error = 0 and hubloc_deleted = 0 and site.site_dead = 0 ",
			dbesc($sender_hash)
		);
		if (! $r) {
			logger('no hubs');
			json_return_and_die($ret);
		}
		$hubs = $r;

		$private = ((array_key_exists('flags', $messages[0]) && in_array('private',$messages[0]['flags'])) ? true : false);
		if($private)
			$env_recips = array('guid' => $sender['guid'], 'guid_sig' => $sender['guid_sig'], 'hash' => $sender_hash);

		$data_packet = json_encode(array('message_list' => $messages));

		foreach($hubs as $hub) {
			$hash = random_string();

			/*
			 * create a notify packet and drop the actual message packet in the queue for pickup
			 */

			$n = zot_build_packet($c[0],'notify',$env_recips,(($private) ? $hub['hubloc_sitekey'] : null),$hub['site_crypto'],$hash,array('message_id' => $data['message_id']));

			queue_insert(array(
				'hash'       => $hash,
				'account_id' => $c[0]['channel_account_id'],
				'channel_id' => $c[0]['channel_id'],
				'posturl'    => $hub['hubloc_callback'],
				'notify'     => $n,
				'msg'        => $data_packet
			));


			$x = q("select count(outq_hash) as total from outq where outq_delivered = 0");
			if(intval($x[0]['total']) > intval(get_config('system','force_queue_threshold',300))) {
				logger('immediate delivery deferred.', LOGGER_DEBUG, LOG_INFO);
				update_queue_item($hash);
				continue;
			}

			/*
			 * invoke delivery to send out the notify packet
			 */

			Zotlabs\Daemon\Master::Summon(array('Deliver', $hash));
		}
	}
	$ret['success'] = true;
	json_return_and_die($ret);
}

function zot_rekey_request($sender,$data) {

	$ret = array('success' => false);

	//	newsig is newkey signed with oldkey

	// The original xchan will remain. In Zot/Receiver we will have imported the new xchan and hubloc to verify
	// the packet authenticity. What we will do now is verify that the keychange operation was signed by the
	// oldkey, and if so change all the abook, abconfig, group, and permission elements which reference the
	// old xchan_hash.

	if((! $data['old_key']) && (! $data['new_key']) && (! $data['new_sig']))
		json_return_and_die($ret);

	$oldhash = make_xchan_hash($data['old_guid'],$data['old_guid_sig']);

	$r = q("select * from xchan where xchan_hash = '%s' limit 1",
		dbesc($oldhash)
	);

	if(! $r) {
		json_return_and_die($ret);
	}

	$xchan = $r[0];

	if(! rsa_verify($data['new_key'],base64url_decode($data['new_sig']),$xchan['xchan_pubkey'])) {
		json_return_and_die($ret);
	}

	$newhash = make_xchan_hash($sender['guid'],$sender['guid_sig']);

	$r = q("select * from xchan where xchan_hash = '%s' limit 1",
		dbesc($newhash)
	);

	$newxchan = $r[0];

	xchan_change_key($xchan,$newxchan,$data);

	$ret['success'] = true;
	json_return_and_die($ret);
}


function zotinfo($arr) {

	$ret = array('success' => false);

	$sig_method = get_config('system','signature_algorithm','sha256');

	$zhash     = ((x($arr,'guid_hash'))  ? $arr['guid_hash']   : '');
	$zguid     = ((x($arr,'guid'))       ? $arr['guid']        : '');
	$zguid_sig = ((x($arr,'guid_sig'))   ? $arr['guid_sig']    : '');
	$zaddr     = ((x($arr,'address'))    ? $arr['address']     : '');
	$ztarget   = ((x($arr,'target'))     ? $arr['target']      : '');
	$zsig      = ((x($arr,'target_sig')) ? $arr['target_sig']  : '');
	$zkey      = ((x($arr,'key'))        ? $arr['key']         : '');
	$mindate   = ((x($arr,'mindate'))    ? $arr['mindate']     : '');
	$token     = ((x($arr,'token'))      ? $arr['token']   : '');

	$feed      = ((x($arr,'feed'))       ? intval($arr['feed']) : 0);

	if($ztarget) {
		if((! $zkey) || (! $zsig) || (! rsa_verify($ztarget,base64url_decode($zsig),$zkey))) {
			logger('zfinger: invalid target signature');
			$ret['message'] = t("invalid target signature");
			return($ret);
		}
	}

	$ztarget_hash = (($ztarget && $zsig) ? make_xchan_hash($ztarget,$zsig) : '' );

	$r = null;

	if(strlen($zhash)) {
		$r = q("select channel.*, xchan.* from channel left join xchan on channel_hash = xchan_hash
			where channel_hash = '%s' limit 1",
			dbesc($zhash)
		);
	}
	elseif(strlen($zguid) && strlen($zguid_sig)) {
		$r = q("select channel.*, xchan.* from channel left join xchan on channel_hash = xchan_hash
			where channel_guid = '%s' and channel_guid_sig = '%s' limit 1",
			dbesc($zguid),
			dbesc($zguid_sig)
		);
	}
	elseif(strlen($zaddr)) {
		if(strpos($zaddr,'[system]') === false) {       /* normal address lookup */
			$r = q("select channel.*, xchan.* from channel left join xchan on channel_hash = xchan_hash
				where ( channel_address = '%s' or xchan_addr = '%s' ) limit 1",
				dbesc($zaddr),
				dbesc($zaddr)
			);
		}

		else {

			/**
			 * The special address '[system]' will return a system channel if one has been defined,
			 * Or the first valid channel we find if there are no system channels.
			 *
			 * This is used by magic-auth if we have no prior communications with this site - and
			 * returns an identity on this site which we can use to create a valid hub record so that
			 * we can exchange signed messages. The precise identity is irrelevant. It's the hub
			 * information that we really need at the other end - and this will return it.
			 *
			 */

			$r = q("select channel.*, xchan.* from channel left join xchan on channel_hash = xchan_hash
				where channel_system = 1 order by channel_id limit 1");
			if(! $r) {
				$r = q("select channel.*, xchan.* from channel left join xchan on channel_hash = xchan_hash
					where channel_removed = 0 order by channel_id limit 1");
			}
		}
	}
	else {
		$ret['message'] = 'Invalid request';
		return($ret);
	}

	if(! $r) {
		$ret['message'] = 'Item not found.';
		return($ret);
	}

	$e = $r[0];

	$id = $e['channel_id'];

	$x = [
			'channel_id' => $id,
			'protocols' => ['zot']
	];
	/**
	 * @hooks channel_protocols
	 *   * \e int \b channel_id
	 *   * \e array \b protocols
	 */
	call_hooks('channel_protocols', $x);

	$protocols = $x['protocols'];

	$sys_channel     = (intval($e['channel_system'])   ? true : false);
	$special_channel = (($e['channel_pageflags'] & PAGE_PREMIUM)  ? true : false);
	$adult_channel   = (($e['channel_pageflags'] & PAGE_ADULT)    ? true : false);
	$censored        = (($e['channel_pageflags'] & PAGE_CENSORED) ? true : false);
	$searchable      = (($e['channel_pageflags'] & PAGE_HIDDEN)   ? false : true);
	$deleted         = (intval($e['xchan_deleted']) ? true : false);

	if($deleted || $censored || $sys_channel)
		$searchable = false;

	$public_forum = false;

	$role = get_pconfig($e['channel_id'],'system','permissions_role');
	if($role === 'forum' || $role === 'repository') {
		$public_forum = true;
	}
	else {
		// check if it has characteristics of a public forum based on custom permissions.
		$m = \Zotlabs\Access\Permissions::FilledAutoperms($e['channel_id']);
		if($m) {
			foreach($m as $k => $v) {
				if($k == 'tag_deliver' && intval($v) == 1)
					$ch ++;
				if($k == 'send_stream' && intval($v) == 0)
					$ch ++;
			}
			if($ch == 2)
				$public_forum = true;
		}
	}


	//  This is for birthdays and keywords, but must check access permissions
	$p = q("select * from profile where uid = %d and is_default = 1",
		intval($e['channel_id'])
	);

	$profile = array();

	if($p) {

		if(! intval($p[0]['publish']))
			$searchable = false;

		$profile['description']   = $p[0]['pdesc'];
		$profile['birthday']      = $p[0]['dob'];
		if(($profile['birthday'] != '0000-00-00') && (($bd = z_birthday($p[0]['dob'],$e['channel_timezone'])) !== ''))
			$profile['next_birthday'] = $bd;

		if($age = age($p[0]['dob'],$e['channel_timezone'],''))
			$profile['age'] = $age;

		$profile['gender']        = $p[0]['gender'];
		$profile['marital']       = $p[0]['marital'];
		$profile['sexual']        = $p[0]['sexual'];
		$profile['locale']        = $p[0]['locality'];
		$profile['region']        = $p[0]['region'];
		$profile['postcode']      = $p[0]['postal_code'];
		$profile['country']       = $p[0]['country_name'];
		$profile['about']         = $p[0]['about'];
		$profile['homepage']      = $p[0]['homepage'];
		$profile['hometown']      = $p[0]['hometown'];

		if($p[0]['keywords']) {
			$tags = array();
			$k = explode(' ',$p[0]['keywords']);
			if($k) {
				foreach($k as $kk) {
					if(trim($kk," \t\n\r\0\x0B,")) {
						$tags[] = trim($kk," \t\n\r\0\x0B,");
					}
				}
			}
			if($tags)
				$profile['keywords'] = $tags;
		}
	}

	$ret['success'] = true;

	// Communication details

	if($token)
		$ret['signed_token'] = base64url_encode(rsa_sign('token.' . $token,$e['channel_prvkey'],$sig_method));


	$ret['guid']           = $e['xchan_guid'];
	$ret['guid_sig']       = $e['xchan_guid_sig'];
	$ret['key']            = $e['xchan_pubkey'];
	$ret['name']           = $e['xchan_name'];
	$ret['name_updated']   = $e['xchan_name_date'];
	$ret['address']        = $e['xchan_addr'];
	$ret['photo_mimetype'] = $e['xchan_photo_mimetype'];
	$ret['photo']          = $e['xchan_photo_l'];
	$ret['photo_updated']  = $e['xchan_photo_date'];
	$ret['url']            = $e['xchan_url'];
	$ret['connections_url']= (($e['xchan_connurl']) ? $e['xchan_connurl'] : z_root() . '/poco/' . $e['channel_address']);
	$ret['follow_url']     = $e['xchan_follow'];
	$ret['target']         = $ztarget;
	$ret['target_sig']     = $zsig;
	$ret['searchable']     = $searchable;
	$ret['protocols']      = $protocols;
	$ret['adult_content']  = $adult_channel;
	$ret['public_forum']   = $public_forum;
	if($deleted)
		$ret['deleted']        = $deleted;

	if(intval($e['channel_removed']))
		$ret['deleted_locally'] = true;


	// premium or other channel desiring some contact with potential followers before connecting.
	// This is a template - %s will be replaced with the follow_url we discover for the return channel.

	if($special_channel) {
		$ret['connect_url'] = (($e['xchan_connpage']) ? $e['xchan_connpage'] : z_root() . '/connect/' . $e['channel_address']);
	}
	// This is a template for our follow url, %s will be replaced with a webbie

	if(! $ret['follow_url'])
		$ret['follow_url'] = z_root() . '/follow?f=&url=%s';

	$permissions = get_all_perms($e['channel_id'],$ztarget_hash,false,false);

	if($ztarget_hash) {
		$permissions['connected'] = false;
		$b = q("select * from abook where abook_xchan = '%s' and abook_channel = %d and abook_pending = 0 limit 1",
			dbesc($ztarget_hash),
			intval($e['channel_id'])
		);
		if($b)
			$permissions['connected'] = true;
	}

	// encrypt this with the default aes256cbc since we cannot be sure at this point which
	// algorithms are preferred for communications with the remote site; notably
	// because ztarget refers to an xchan and we don't necessarily know the origination
	// location.

	$ret['permissions'] = (($ztarget && $zkey) ? crypto_encapsulate(json_encode($permissions),$zkey) : $permissions);

	if($permissions['view_profile'])
		$ret['profile']  = $profile;

	// array of (verified) hubs this channel uses

	$x = zot_encode_locations($e);
	if($x)
		$ret['locations'] = $x;

	$ret['site'] = zot_site_info($e['channel_prvkey']);

	check_zotinfo($e,$x,$ret);

	/**
	 * @hooks zot_finger
	 *   Called when a zot-info packet has been requested (this is our webfinger discovery mechanism).
	 *   * \e array The final return array
	 */
	call_hooks('zot_finger', $ret);

	return($ret);
}


function zot_site_info($channel_key = '') {

	$signing_key = get_config('system','prvkey');
	$sig_method  = get_config('system','signature_algorithm','sha256');

	$ret = [];
	$ret['site'] = [];
	$ret['site']['url'] = z_root();
	if($channel_key) {
		$ret['site']['url_sig'] = base64url_encode(rsa_sign(z_root(),$channel_key,$sig_method));
	}
	$ret['site']['url_site_sig'] = base64url_encode(rsa_sign(z_root(),$signing_key,$sig_method));
	$ret['site']['post'] = z_root() . '/post';
	$ret['site']['openWebAuth']  = z_root() . '/owa';
	$ret['site']['authRedirect'] = z_root() . '/magic';
	$ret['site']['key'] = get_config('system','pubkey');

	$dirmode = get_config('system','directory_mode');
	if(($dirmode === false) || ($dirmode == DIRECTORY_MODE_NORMAL))
		$ret['site']['directory_mode'] = 'normal';

	if($dirmode == DIRECTORY_MODE_PRIMARY)
		$ret['site']['directory_mode'] = 'primary';
	elseif($dirmode == DIRECTORY_MODE_SECONDARY)
		$ret['site']['directory_mode'] = 'secondary';
	elseif($dirmode == DIRECTORY_MODE_STANDALONE)
		$ret['site']['directory_mode'] = 'standalone';
	if($dirmode != DIRECTORY_MODE_NORMAL)
		$ret['site']['directory_url'] = z_root() . '/dirsearch';


	$ret['site']['encryption'] = crypto_methods();
	$ret['site']['signing'] = signing_methods();
	$ret['site']['zot'] = Zotlabs\Lib\System::get_zot_revision();

	// hide detailed site information if you're off the grid

	if($dirmode != DIRECTORY_MODE_STANDALONE) {

		$register_policy = intval(get_config('system','register_policy'));

		if($register_policy == REGISTER_CLOSED)
			$ret['site']['register_policy'] = 'closed';
		if($register_policy == REGISTER_APPROVE)
			$ret['site']['register_policy'] = 'approve';
		if($register_policy == REGISTER_OPEN)
			$ret['site']['register_policy'] = 'open';


		$access_policy = intval(get_config('system','access_policy'));

		if($access_policy == ACCESS_PRIVATE)
			$ret['site']['access_policy'] = 'private';
		if($access_policy == ACCESS_PAID)
			$ret['site']['access_policy'] = 'paid';
		if($access_policy == ACCESS_FREE)
			$ret['site']['access_policy'] = 'free';
		if($access_policy == ACCESS_TIERED)
			$ret['site']['access_policy'] = 'tiered';

		$ret['site']['accounts'] = account_total();

		require_once('include/channel.php');
		$ret['site']['channels'] = channel_total();

		$ret['site']['admin'] = get_config('system','admin_email');

		$visible_plugins = array();
		if(is_array(App::$plugins) && count(App::$plugins)) {
			$r = q("select * from addon where hidden = 0");
			if($r)
				foreach($r as $rr)
					$visible_plugins[] = $rr['aname'];
		}

		$ret['site']['plugins']    = $visible_plugins;
		$ret['site']['sitehash']   = get_config('system','location_hash');
		$ret['site']['sitename']   = get_config('system','sitename');
		$ret['site']['sellpage']   = get_config('system','sellpage');
		$ret['site']['location']   = get_config('system','site_location');
		$ret['site']['realm']      = get_directory_realm();
		$ret['site']['project']    = Zotlabs\Lib\System::get_platform_name() . ' ' . Zotlabs\Lib\System::get_server_role();
		$ret['site']['version']    = Zotlabs\Lib\System::get_project_version();

	}

	return $ret['site'];
}

/**
 * @brief
 *
 * @param array $channel
 * @param array $locations
 * @param[out] array $ret
 *   \e array \b locations result of zot_encode_locations()
 */
function check_zotinfo($channel, $locations, &$ret) {

//	logger('locations: ' . print_r($locations,true),LOGGER_DATA, LOG_DEBUG);

	// This function will likely expand as we find more things to detect and fix.
	// 1. Because magic-auth is reliant on it, ensure that the system channel has a valid hubloc
	//    Force this to be the case if anything is found to be wrong with it.

	/// @FIXME ensure that the system channel exists in the first place and has an xchan

	if($channel['channel_system']) {
		// the sys channel must have a location (hubloc)
		$valid_location = false;
		if((count($locations) === 1) && ($locations[0]['primary']) && (! $locations[0]['deleted'])) {
			if((rsa_verify($locations[0]['url'],base64url_decode($locations[0]['url_sig']),$channel['channel_pubkey']))
				&& ($locations[0]['sitekey'] === get_config('system','pubkey'))
				&& ($locations[0]['url'] === z_root()))
				$valid_location = true;
			else
				logger('sys channel: invalid url signature');
		}

		if((! $locations) || (! $valid_location)) {

			logger('System channel locations are not valid. Attempting repair.');

			// Don't trust any existing records. Just get rid of them, but only do this
			// for the sys channel as normal channels will be trickier.

			q("delete from hubloc where hubloc_hash = '%s'",
				dbesc($channel['channel_hash'])
			);

			$r = hubloc_store_lowlevel(
				[
					'hubloc_guid'     => $channel['channel_guid'],
					'hubloc_guid_sig' => $channel['channel_guid_sig'],
					'hubloc_hash'     => $channel['channel_hash'],
					'hubloc_addr'     => channel_reddress($channel),
					'hubloc_network'  => 'zot',
					'hubloc_primary'  => 1,
					'hubloc_url'      => z_root(),
					'hubloc_url_sig'  => base64url_encode(rsa_sign(z_root(),$channel['channel_prvkey'])),
					'hubloc_host'     => App::get_hostname(),
					'hubloc_callback' => z_root() . '/post',
					'hubloc_sitekey'  => get_config('system','pubkey'),
					'hubloc_updated'  => datetime_convert(),
				]
			);

			if($r) {
				$x = zot_encode_locations($channel);
				if($x) {
					$ret['locations'] = $x;
				}
			}
			else {
				logger('Unable to store sys hub location');
			}
		}
	}
}

/**
 * @brief
 *
 * @param array $dr
 * @return boolean
 */
function delivery_report_is_storable($dr) {

	if(get_config('system', 'disable_dreport'))
		return false;

	/**
	 * @hooks dreport_is_storable
	 *   Called before storing a dreport record to determine whether to store it.
	 *   * \e array
	 */
	call_hooks('dreport_is_storable', $dr);

	// let plugins accept or reject - if neither, continue on
	if(array_key_exists('accept',$dr) && intval($dr['accept']))
		return true;
	if(array_key_exists('reject',$dr) && intval($dr['reject']))
		return false;

	if(! ($dr['sender']))
		return false;

	// Is the sender one of our channels?

	$c = q("select channel_id from channel where channel_hash = '%s' limit 1",
		dbesc($dr['sender'])
	);
	if(! $c)
		return false;


	// is the recipient one of our connections, or do we want to store every report?

	$r = explode(' ', $dr['recipient']);
	$rxchan = $r[0];
	$pcf = get_pconfig($c[0]['channel_id'],'system','dreport_store_all');
	if($pcf)
		return true;

	// We always add ourself as a recipient to private and relayed posts
	// So if a remote site says they can't find us, that's no big surprise
	// and just creates a lot of extra report noise

	if(($dr['location'] !== z_root()) && ($dr['sender'] === $rxchan) && ($dr['status'] === 'recipient_not_found'))
		return false;

	// If you have a private post with a recipient list, every single site is going to report
	// back a failed delivery for anybody on that list that isn't local to them. We're only
	// concerned about this if we have a local hubloc record which says we expected them to
	// have a channel on that site.

	$r = q("select hubloc_id from hubloc where hubloc_hash = '%s' and hubloc_url = '%s'",
		dbesc($rxchan),
		dbesc($dr['location'])
	);
	if((! $r) && ($dr['status'] === 'recipient_not_found'))
		return false;

	$r = q("select abook_id from abook where abook_xchan = '%s' and abook_channel = %d limit 1",
		dbesc($rxchan),
		intval($c[0]['channel_id'])
	);
	if($r)
		return true;

	return false;
}


/**
 * @brief
 *
 * @param array $hub
 * @param string $sitekey (optional, default empty)
 *
 * @return string hubloc_url
 */
function update_hub_connected($hub, $sitekey = '') {

	if($sitekey) {

		/*
		 * This hub has now been proven to be valid.
		 * Any hub with the same URL and a different sitekey cannot be valid.
		 * Get rid of them (mark them deleted). There's a good chance they were re-installs.
		 */

		q("update hubloc set hubloc_deleted = 1, hubloc_error = 1 where hubloc_url = '%s' and hubloc_sitekey != '%s' ",
			dbesc($hub['hubloc_url']),
			dbesc($sitekey)
		);

	}
	else {
		$sitekey = $hub['sitekey'];
	}

	// $sender['sitekey'] is a new addition to the protocol to distinguish
	// hublocs coming from re-installed sites. Older sites will not provide
	// this field and we have to still mark them valid, since we can't tell
	// if this hubloc has the same sitekey as the packet we received.


	// Update our DB to show when we last communicated successfully with this hub
	// This will allow us to prune dead hubs from using up resources

	$t = datetime_convert('UTC', 'UTC', 'now - 15 minutes');

	$r = q("update hubloc set hubloc_connected = '%s' where hubloc_id = %d and hubloc_sitekey = '%s' and hubloc_connected < '%s' ",
		dbesc(datetime_convert()),
		intval($hub['hubloc_id']),
		dbesc($sitekey),
		dbesc($t)
	);

	// a dead hub came back to life - reset any tombstones we might have

	if(intval($hub['hubloc_error'])) {
		q("update hubloc set hubloc_error = 0 where hubloc_id = %d and hubloc_sitekey = '%s' ",
			intval($hub['hubloc_id']),
			dbesc($sitekey)
		);
		if(intval($hub['hubloc_orphancheck'])) {
			q("update hubloc set hubloc_orphancheck = 0 where hubloc_id = %d and hubloc_sitekey = '%s' ",
				intval($hub['hubloc_id']),
				dbesc($sitekey)
			);
		}
		q("update xchan set xchan_orphan = 0 where xchan_orphan = 1 and xchan_hash = '%s'",
			dbesc($hub['hubloc_hash'])
		);
	}

	return $hub['hubloc_url'];
}

/**
 * @brief Useful to get a health check on a remote site.
 *
 * This will let us know if any important communication details
 * that we may have stored are no longer valid, regardless of xchan details.
 *
 * @return json_return_and_die()
 */
function zot_reply_ping() {

	$ret = array('success'=> false);

	logger('POST: got ping send pong now back: ' . z_root() , LOGGER_DEBUG );

	$ret['success'] = true;
	$ret['site'] = array();
	$ret['site']['url'] = z_root();
	$ret['site']['url_sig'] = base64url_encode(rsa_sign(z_root(),get_config('system','prvkey')));
	$ret['site']['sitekey'] = get_config('system','pubkey');

	json_return_and_die($ret);
}

function zot_reply_pickup($data) {

	$ret = array('success'=> false);

	/*
	 * The 'pickup' message arrives with a tracking ID which is associated with a particular outq_hash
	 * First verify that that the returned signatures verify, then check that we have an outbound queue item
	 * with the correct hash.
	 * If everything verifies, find any/all outbound messages in the queue for this hubloc and send them back
	 */

	if((! $data['secret']) || (! $data['secret_sig'])) {
		$ret['message'] = 'no verification signature';
		logger('mod_zot: pickup: ' . $ret['message'], LOGGER_DEBUG);

		json_return_and_die($ret);
	}

	$r = q("select distinct hubloc_sitekey from hubloc where hubloc_url = '%s' and hubloc_callback = '%s' and hubloc_sitekey != '' group by hubloc_sitekey ",
		dbesc($data['url']),
		dbesc($data['callback'])
	);
	if(! $r) {
		$ret['message'] = 'site not found';
		logger('mod_zot: pickup: ' . $ret['message']);

		json_return_and_die($ret);
	}

	foreach ($r as $hubsite) {

		// verify the url_sig
		// If the server was re-installed at some point, there could be multiple hubs with the same url and callback.
		// Only one will have a valid key.

		$forgery = true;
		$secret_fail = true;

		$sitekey = $hubsite['hubloc_sitekey'];

		logger('mod_zot: Checking sitekey: ' . $sitekey, LOGGER_DATA, LOG_DEBUG);

		if(rsa_verify($data['callback'],base64url_decode($data['callback_sig']),$sitekey)) {
			$forgery = false;
		}
		if(rsa_verify($data['secret'],base64url_decode($data['secret_sig']),$sitekey)) {
			$secret_fail = false;
		}
		if((! $forgery) && (! $secret_fail))
			break;
	}

	if($forgery) {
		$ret['message'] = 'possible site forgery';
		logger('mod_zot: pickup: ' . $ret['message']);

		json_return_and_die($ret);
	}

	if($secret_fail) {
		$ret['message'] = 'secret validation failed';
		logger('mod_zot: pickup: ' . $ret['message']);

		json_return_and_die($ret);
	}

	/*
	 * If we made it to here, the signatures verify, but we still don't know if the tracking ID is valid.
	 * It wouldn't be an error if the tracking ID isn't found, because we may have sent this particular
	 * queue item with another pickup (after the tracking ID for the other pickup  was verified).
	 */

	$r = q("select outq_posturl from outq where outq_hash = '%s' and outq_posturl = '%s' limit 1",
		dbesc($data['secret']),
		dbesc($data['callback'])
	);
	if(! $r) {
		$ret['message'] = 'nothing to pick up';
		logger('mod_zot: pickup: ' . $ret['message']);

		json_return_and_die($ret);
	}

	/*
	 * Everything is good if we made it here, so find all messages that are going to this location
	 * and send them all.
	 */

	$r = q("select * from outq where outq_posturl = '%s'",
		dbesc($data['callback'])
	);
	if($r) {
		logger('mod_zot: successful pickup message received from ' . $data['callback'] . ' ' . count($r) . ' message(s) picked up', LOGGER_DEBUG);

		$ret['success'] = true;
		$ret['pickup'] = array();
		foreach($r as $rr) {
			if($rr['outq_msg']) {
				$x = json_decode($rr['outq_msg'],true);

				if(! $x)
					continue;

				if(is_array($x) && array_key_exists('message_list',$x)) {
					foreach($x['message_list'] as $xx) {
						$ret['pickup'][] = array('notify' => json_decode($rr['outq_notify'],true),'message' => $xx);
					}
				}
				else
					$ret['pickup'][] = array('notify' => json_decode($rr['outq_notify'],true),'message' => $x);

				remove_queue_item($rr['outq_hash']);
			}
		}
	}

	// this is a bit of a hack because we don't have the hubloc_url here, only the callback url.
	// worst case is we'll end up using aes256cbc if they've got a different post endpoint

	$x = q("select site_crypto from site where site_url = '%s' limit 1",
		dbesc(str_replace('/post','',$data['callback']))
	);
	$algorithm = zot_best_algorithm(($x) ? $x[0]['site_crypto'] : '');

	$encrypted = crypto_encapsulate(json_encode($ret),$sitekey,$algorithm);

	json_return_and_die($encrypted);
	/* pickup: end */
}



function zot_reply_auth_check($data,$encrypted_packet) {

	$ret = array('success' => false);

	/*
	 * Requestor visits /magic/?dest=somewhere on their own site with a browser
	 * magic redirects them to $destsite/post [with auth args....]
	 * $destsite sends an auth_check packet to originator site
	 * The auth_check packet is handled here by the originator's site
	 * - the browser session is still waiting
	 * inside $destsite/post for everything to verify
	 * If everything checks out we'll return a token to $destsite
	 * and then $destsite will verify the token, authenticate the browser
	 * session and then redirect to the original destination.
	 * If authentication fails, the redirection to the original destination
	 * will still take place but without authentication.
	 */
	logger('mod_zot: auth_check', LOGGER_DEBUG);

	if (! $encrypted_packet) {
		logger('mod_zot: auth_check packet was not encrypted.');
		$ret['message'] .= 'no packet encryption' . EOL;

		json_return_and_die($ret);
	}

	$arr = $data['sender'];
	$sender_hash = make_xchan_hash($arr['guid'],$arr['guid_sig']);

	// garbage collect any old unused notifications

	/**
	 * @TODO This was and should be 10 minutes but my hosting provider has time lag between the DB and
	 * the web server. We should probably convert this to webserver time rather than DB time so
	 * that the different clocks won't affect it and allow us to keep the time short.
	 */
	Zotlabs\Lib\Verify::purge('auth', '30 MINUTE');

	$y = q("select xchan_pubkey from xchan where xchan_hash = '%s' limit 1",
		dbesc($sender_hash)
	);

	// We created a unique hash in mod/magic.php when we invoked remote auth, and stored it in
	// the verify table. It is now coming back to us as 'secret' and is signed by a channel at the other end.
	// First verify their signature. We will have obtained a zot-info packet from them as part of the sender
	// verification.

	if ((! $y) || (! rsa_verify($data['secret'], base64url_decode($data['secret_sig']),$y[0]['xchan_pubkey']))) {
		logger('mod_zot: auth_check: sender not found or secret_sig invalid.');
		$ret['message'] .= 'sender not found or sig invalid ' . print_r($y,true) . EOL;

		json_return_and_die($ret);
	}

	// There should be exactly one recipient, the original auth requestor

	$ret['message'] .= 'recipients ' . print_r($recipients,true) . EOL;

	if ($data['recipients']) {

		$arr = $data['recipients'][0];
		$recip_hash = make_xchan_hash($arr['guid'], $arr['guid_sig']);
		$c = q("select channel_id, channel_account_id, channel_prvkey from channel where channel_hash = '%s' limit 1",
			dbesc($recip_hash)
		);
		if (! $c) {
			logger('mod_zot: auth_check: recipient channel not found.');
			$ret['message'] .= 'recipient not found.' . EOL;

			json_return_and_die($ret);
		}

		$confirm = base64url_encode(rsa_sign($data['secret'] . $recip_hash,$c[0]['channel_prvkey']));

		// This additionally checks for forged sites since we already stored the expected result in meta
		// and we've already verified that this is them via zot_gethub() and that their key signed our token

		$z = Zotlabs\Lib\Verify::match('auth',$c[0]['channel_id'],$data['secret'],$data['sender']['url']);
		if (! $z) {
			logger('mod_zot: auth_check: verification key not found.');
			$ret['message'] .= 'verification key not found' . EOL;

			json_return_and_die($ret);
		}

		$u = q("select account_service_class from account where account_id = %d limit 1",
			intval($c[0]['channel_account_id'])
		);

		logger('mod_zot: auth_check: success', LOGGER_DEBUG);
		$ret['success'] = true;
		$ret['confirm'] = $confirm;
		if ($u && $u[0]['account_service_class'])
			$ret['service_class'] = $u[0]['account_service_class'];

		// Set "do not track" flag if this site or this channel's profile is restricted
		// in some way

		if (intval(get_config('system','block_public')))
			$ret['DNT'] = true;
		if (! perm_is_allowed($c[0]['channel_id'],'','view_profile'))
			$ret['DNT'] = true;
		if (get_pconfig($c[0]['channel_id'],'system','do_not_track'))
			$ret['DNT'] = true;
		if (get_pconfig($c[0]['channel_id'],'system','hide_online_status'))
			$ret['DNT'] = true;

		json_return_and_die($ret);
	}

	json_return_and_die($ret);
}

/**
 * @brief
 *
 * @param array $sender
 * @param array $recipients
 *
 * return json_return_and_die()
 */
function zot_reply_purge($sender, $recipients) {

	$ret = array('success' => false);

	if ($recipients) {
		// basically this means "unfriend"
		foreach ($recipients as $recip) {
			$r = q("select channel.*,xchan.* from channel
				left join xchan on channel_hash = xchan_hash
				where channel_guid = '%s' and channel_guid_sig = '%s' limit 1",
				dbesc($recip['guid']),
				dbesc($recip['guid_sig'])
			);
			if ($r) {
				$r = q("select abook_id from abook where uid = %d and abook_xchan = '%s' limit 1",
					intval($r[0]['channel_id']),
					dbesc(make_xchan_hash($sender['guid'],$sender['guid_sig']))
				);
				if ($r) {
					contact_remove($r[0]['channel_id'],$r[0]['abook_id']);
				}
			}
		}
		$ret['success'] = true;
	}
	else {
		// Unfriend everybody - basically this means the channel has committed suicide
		$arr = $sender;
		$sender_hash = make_xchan_hash($arr['guid'],$arr['guid_sig']);

		remove_all_xchan_resources($sender_hash);

		$ret['success'] = true;
	}

	json_return_and_die($ret);
}

/**
 * @brief Remote channel info (such as permissions or photo or something)
 * has been updated. Grab a fresh copy and sync it.
 *
 * The difference between refresh and force_refresh is that force_refresh
 * unconditionally creates a directory update record, even if no changes were
 * detected upon processing.
 *
 * @param array $sender
 * @param array $recipients
 *
 * @return json_return_and_die()
 */
function zot_reply_refresh($sender, $recipients) {

	$ret = array('success' => false);

	if($recipients) {

		// This would be a permissions update, typically for one connection

		foreach ($recipients as $recip) {
			$r = q("select channel.*,xchan.* from channel
				left join xchan on channel_hash = xchan_hash
				where channel_guid = '%s' and channel_guid_sig = '%s' limit 1",
				dbesc($recip['guid']),
				dbesc($recip['guid_sig'])
			);

			$x = zot_refresh(array(
					'xchan_guid'     => $sender['guid'],
					'xchan_guid_sig' => $sender['guid_sig'],
					'hubloc_url'     => $sender['url']
			), $r[0], (($msgtype === 'force_refresh') ? true : false));
		}
	}
	else {
		// system wide refresh

		$x = zot_refresh(array(
			'xchan_guid'     => $sender['guid'],
			'xchan_guid_sig' => $sender['guid_sig'],
			'hubloc_url'     => $sender['url']
		), null, (($msgtype === 'force_refresh') ? true : false));
	}

	$ret['success'] = true;
	json_return_and_die($ret);
}


function zot6_check_sig() {

	$ret = [ 'success' => false ];

	logger('server: ' . print_r($_SERVER,true), LOGGER_DATA);

	if(array_key_exists('HTTP_SIGNATURE',$_SERVER)) {
		$sigblock = \Zotlabs\Web\HTTPSig::parse_sigheader($_SERVER['HTTP_SIGNATURE']);
		if($sigblock) {
			$keyId = $sigblock['keyId'];

			if($keyId) {
				$r = q("select hubloc.*, site_crypto from hubloc left join site on hubloc_url = site_url
					where hubloc_addr = '%s' ",
					dbesc(str_replace('acct:','',$keyId))
				);
				if($r) {
					foreach($r as $hubloc) {
						$verified = \Zotlabs\Web\HTTPSig::verify('',$hubloc['xchan_pubkey']);
						if($verified && $verified['header_signed'] && $verified['header_valid'] && $verified['content_signed'] && $verified['content_valid']) {
							$ret['hubloc'] = $hubloc;
							$ret['success'] = true;
							return $ret;
						}
					}
				}
			}
		}
	}

	return $ret;
}

function zot_reply_notify($data) {

	$ret = array('success' => false);

	logger('notify received from ' . $data['sender']['url']);

	$async = get_config('system','queued_fetch');

	if($async) {
		// add to receive queue
		// qreceive_add($data);
	}
	else {
		$x = zot_fetch($data);
		$ret['delivery_report'] = $x;
	}

	$ret['success'] = true;
	json_return_and_die($ret);
}