aboutsummaryrefslogtreecommitdiffstats
path: root/include/crypto.php
blob: 105c1c54f29a1a18c599989b3c03f548739d7194 (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
<?php /** @file */

require_once('library/ASNValue.class.php');
require_once('library/asn1.php');

function rsa_sign($data,$key,$alg = 'sha256') {
	if(! $key)
		return 'no key';
	$sig = '';
	if(intval(OPENSSL_ALGO_SHA256) && $alg === 'sha256')
		$alg = OPENSSL_ALGO_SHA256;
	openssl_sign($data,$sig,$key,$alg);
	return $sig;
}

function rsa_verify($data,$sig,$key,$alg = 'sha256') {

	if(! $key)
		return false;

	if(intval(OPENSSL_ALGO_SHA256) && $alg === 'sha256')
		$alg = OPENSSL_ALGO_SHA256;
	$verify = @openssl_verify($data,$sig,$key,$alg);

	if($verify === (-1)) {
		while($msg = openssl_error_string())
			logger('openssl_verify: ' . $msg,LOGGER_NORMAL,LOG_ERR);
		btlogger('openssl_verify: key: ' . $key, LOGGER_DEBUG, LOG_ERR); 
	}

	return (($verify > 0) ? true : false);
}


function AES256CBC_encrypt($data,$key,$iv) {

	return openssl_encrypt($data,'aes-256-cbc',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}

function AES256CBC_decrypt($data,$key,$iv) {

	return openssl_decrypt($data,'aes-256-cbc',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}


function AES128CBC_encrypt($data,$key,$iv) {
	$key = substr($key,0,16);
	$iv = substr($iv,0,16);
	return openssl_encrypt($data,'aes-128-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}

function AES128CBC_decrypt($data,$key,$iv) {
	$key = substr($key,0,16);
	$iv = substr($iv,0,16);
	return openssl_decrypt($data,'aes-128-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}


function AES256CTR_encrypt($data,$key,$iv) {
	$key = substr($key,0,32);
	$iv = substr($iv,0,16);
	return openssl_encrypt($data,'aes-256-ctr',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}

function AES256CTR_decrypt($data,$key,$iv) {
	$key = substr($key,0,32);
	$iv = substr($iv,0,16);
	return openssl_decrypt($data,'aes-256-ctr',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}


function CAMELLIA256CFB_encrypt($data,$key,$iv) {
	$key = substr($key,0,32);
	$iv = substr($iv,0,16);
	return openssl_encrypt($data,'camellia-256-cfb',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}

function CAMELLIA256CFB_decrypt($data,$key,$iv) {
	$key = substr($key,0,32);
	$iv = substr($iv,0,16);
	return openssl_decrypt($data,'camellia-256-cfb',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0"));
}


function CAST5CBC_encrypt($data,$key,$iv) {
	$key = substr($key,0,16);
	$iv = substr($iv,0,8);
	return openssl_encrypt($data,'cast5-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,8,"\0"));
}

function CAST5CBC_decrypt($data,$key,$iv) {
	$key = substr($key,0,16);
	$iv = substr($iv,0,8);
	return openssl_decrypt($data,'cast5-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,8,"\0"));
}

function CAST5CFB_encrypt($data,$key,$iv) {
	$key = substr($key,0,16);
	$iv = substr($iv,0,8);
	return openssl_encrypt($data,'cast5-cfb',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,8,"\0"));
}

function CAST5CFB_decrypt($data,$key,$iv) {
	$key = substr($key,0,16);
	$iv = substr($iv,0,8);
	return openssl_decrypt($data,'cast5-cfb',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,8,"\0"));
}



function crypto_encapsulate($data,$pubkey,$alg='aes256cbc') {
	$fn = strtoupper($alg) . '_encrypt';
	
	if($alg === 'aes256cbc')
		return aes_encapsulate($data,$pubkey);

	return other_encapsulate($data,$pubkey,$alg);

}

function other_encapsulate($data,$pubkey,$alg) {
	if(! $pubkey)
		logger('no key. data: ' . $data);

	$fn = strtoupper($alg) . '_encrypt';
	if(function_exists($fn)) {

		// A bit hesitant to use openssl_random_pseudo_bytes() as we know
		// it has been historically targeted by US agencies for 'weakening'.
		// It is still arguably better than trying to come up with an
		// alternative cryptographically secure random generator.
		// There is little point in using the optional second arg to flag the
		// assurance of security since it is meaningless if the source algorithms
		// have been compromised. Also none of this matters if RSA has been
		// compromised by state actors and evidence is mounting that this has
		// already happened.   

		$result = [ 'encrypted' => true ];
		$key = openssl_random_pseudo_bytes(256);
		$iv  = openssl_random_pseudo_bytes(256);
		$result['data'] = base64url_encode($fn($data,$key,$iv),true);
		// log the offending call so we can track it down
		if(! openssl_public_encrypt($key,$k,$pubkey)) {
			$x = debug_backtrace();
			logger('RSA failed. ' . print_r($x[0],true));
		}

		$result['alg'] = $alg;
	 	$result['key'] = base64url_encode($k,true);
		openssl_public_encrypt($iv,$i,$pubkey);
		$result['iv'] = base64url_encode($i,true);
		return $result;
	}
	else {
		$x = [ 'data' => $data, 'pubkey' => $pubkey, 'alg' => $alg, 'result' => $data ];
		call_hooks('other_encapsulate', $x);
		return $x['result'];
	}
}

function crypto_methods() {

	// aes256cbc is provided for compatibility with earlier zot implementations which assume 32-byte key and 16-byte iv. 
	// other_encapsulate() now produces these longer keys/ivs by default so that it is difficult to guess a
	// particular implementation or choice of underlying implementations based on the key/iv length. 
	// The actual methods are responsible for deriving the actual key/iv from the provided parameters;
	// possibly by truncation or segmentation - though many other methods could be used.  

	$r = [ 'aes256ctr', 'camellia256cfb', 'cast5cfb', 'aes256cbc', 'aes128cbc', 'cast5cbc' ];
	call_hooks('crypto_methods',$r);
	return $r;

}


function signing_methods() {


	$r = [ 'sha256' ];
	call_hooks('signing_methods',$r);
	return $r;

}


function aes_encapsulate($data,$pubkey) {
	if(! $pubkey)
		logger('aes_encapsulate: no key. data: ' . $data);
	$key = openssl_random_pseudo_bytes(32);
	$iv  = openssl_random_pseudo_bytes(16);

	$result = [ 'encrypted' => true ];

	$result['data'] = base64url_encode(AES256CBC_encrypt($data,$key,$iv),true);
	// log the offending call so we can track it down
	if(! openssl_public_encrypt($key,$k,$pubkey)) {
		$x = debug_backtrace();
		logger('aes_encapsulate: RSA failed. ' . print_r($x[0],true));
	}
	$result['alg'] = 'aes256cbc';
 	$result['key'] = base64url_encode($k,true);
	openssl_public_encrypt($iv,$i,$pubkey);
	$result['iv'] = base64url_encode($i,true);
	return $result;
}

function crypto_unencapsulate($data,$prvkey) {
	if(! $data)
		return;
	$alg = ((array_key_exists('alg',$data)) ? $data['alg'] : 'aes256cbc');
	if($alg === 'aes256cbc')
		return aes_unencapsulate($data,$prvkey);

	return other_unencapsulate($data,$prvkey,$alg);

}

function other_unencapsulate($data,$prvkey,$alg) {
	$fn = strtoupper($alg) . '_decrypt';
	if(function_exists($fn)) {
		openssl_private_decrypt(base64url_decode($data['key']),$k,$prvkey);
		openssl_private_decrypt(base64url_decode($data['iv']),$i,$prvkey);
		return $fn(base64url_decode($data['data']),$k,$i);
	}
	else {
		$x = [ 'data' => $data, 'prvkey' => $prvkey, 'alg' => $alg, 'result' => $data ];
		call_hooks('other_unencapsulate',$x);
		return $x['result'];
	}
}


function aes_unencapsulate($data,$prvkey) {
	openssl_private_decrypt(base64url_decode($data['key']),$k,$prvkey);
	openssl_private_decrypt(base64url_decode($data['iv']),$i,$prvkey);
	return AES256CBC_decrypt(base64url_decode($data['data']),$k,$i);
}

function new_keypair($bits) {

	$openssl_options = array(
		'digest_alg'       => 'sha1',
		'private_key_bits' => $bits,
		'encrypt_key'      => false 
	);

	$conf = get_config('system','openssl_conf_file');
	if($conf)
		$openssl_options['config'] = $conf;
	
	$result = openssl_pkey_new($openssl_options);

	if(empty($result)) {
		logger('new_keypair: failed');
		return false;
	}

	// Get private key

	$response = array('prvkey' => '', 'pubkey' => '');

	openssl_pkey_export($result, $response['prvkey']);

	// Get public key
	$pkey = openssl_pkey_get_details($result);
	$response['pubkey'] = $pkey["key"];

	return $response;

}

function DerToPem($Der, $Private=false)
{
    //Encode:
    $Der = base64_encode($Der);
    //Split lines:
    $lines = str_split($Der, 65);
    $body = implode("\n", $lines);
    //Get title:
    $title = $Private? 'RSA PRIVATE KEY' : 'PUBLIC KEY';
    //Add wrapping:
    $result = "-----BEGIN {$title}-----\n";
    $result .= $body . "\n";
    $result .= "-----END {$title}-----\n";
 
    return $result;
}

function DerToRsa($Der)
{
    //Encode:
    $Der = base64_encode($Der);
    //Split lines:
    $lines = str_split($Der, 64);
    $body = implode("\n", $lines);
    //Get title:
    $title = 'RSA PUBLIC KEY';
    //Add wrapping:
    $result = "-----BEGIN {$title}-----\n";
    $result .= $body . "\n";
    $result .= "-----END {$title}-----\n";
 
    return $result;
}


function pkcs8_encode($Modulus,$PublicExponent) {
	//Encode key sequence
	$modulus = new ASNValue(ASNValue::TAG_INTEGER);
	$modulus->SetIntBuffer($Modulus);
	$publicExponent = new ASNValue(ASNValue::TAG_INTEGER);
	$publicExponent->SetIntBuffer($PublicExponent);
	$keySequenceItems = array($modulus, $publicExponent);
	$keySequence = new ASNValue(ASNValue::TAG_SEQUENCE);
	$keySequence->SetSequence($keySequenceItems);
	//Encode bit string
	$bitStringValue = $keySequence->Encode();
	$bitStringValue = chr(0x00) . $bitStringValue; //Add unused bits byte
	$bitString = new ASNValue(ASNValue::TAG_BITSTRING);
	$bitString->Value = $bitStringValue;
	//Encode body
	$bodyValue = "\x30\x0d\x06\x09\x2a\x86\x48\x86\xf7\x0d\x01\x01\x01\x05\x00" . $bitString->Encode();
	$body = new ASNValue(ASNValue::TAG_SEQUENCE);
	$body->Value = $bodyValue;
	//Get DER encoded public key:
	$PublicDER = $body->Encode();
	return $PublicDER;
}


function pkcs1_encode($Modulus,$PublicExponent) {
	//Encode key sequence
	$modulus = new ASNValue(ASNValue::TAG_INTEGER);
	$modulus->SetIntBuffer($Modulus);
	$publicExponent = new ASNValue(ASNValue::TAG_INTEGER);
	$publicExponent->SetIntBuffer($PublicExponent);
	$keySequenceItems = array($modulus, $publicExponent);
	$keySequence = new ASNValue(ASNValue::TAG_SEQUENCE);
	$keySequence->SetSequence($keySequenceItems);
	//Encode bit string
	$bitStringValue = $keySequence->Encode();
	return $bitStringValue;
}


// http://stackoverflow.com/questions/27568570/how-to-convert-raw-modulus-exponent-to-rsa-public-key-pem-format
function metopem($m,$e) {
	$der = pkcs8_encode($m,$e);
	$key = DerToPem($der,false);
	return $key;
}	


function pubrsatome($key,&$m,&$e) {
	require_once('library/asn1.php');

	$lines = explode("\n",$key);
	unset($lines[0]);
	unset($lines[count($lines)]);
	$x = base64_decode(implode('',$lines));

	$r = ASN_BASE::parseASNString($x);

	$m = base64url_decode($r[0]->asnData[0]->asnData);
	$e = base64url_decode($r[0]->asnData[1]->asnData);
}


function rsatopem($key) {
	pubrsatome($key,$m,$e);
	return(metopem($m,$e));
}

function pemtorsa($key) {
	pemtome($key,$m,$e);
	return(metorsa($m,$e));
}

function pemtome($key,&$m,&$e) {
	$lines = explode("\n",$key);
	unset($lines[0]);
	unset($lines[count($lines)]);
	$x = base64_decode(implode('',$lines));

	$r = ASN_BASE::parseASNString($x);

	$m = base64url_decode($r[0]->asnData[1]->asnData[0]->asnData[0]->asnData);
	$e = base64url_decode($r[0]->asnData[1]->asnData[0]->asnData[1]->asnData);
}

function metorsa($m,$e) {
	$der = pkcs1_encode($m,$e);
	$key = DerToRsa($der);
	return $key;
}	



function salmon_key($pubkey) {
	pemtome($pubkey,$m,$e);
	return 'RSA' . '.' . base64url_encode($m,true) . '.' . base64url_encode($e,true) ;
}


function convert_salmon_key($key) {

	if(strstr($key,','))
		$rawkey = substr($key,strpos($key,',')+1);
	else
		$rawkey = substr($key,5);

	$key_info = explode('.',$rawkey);

	$m = base64url_decode($key_info[1]);
	$e = base64url_decode($key_info[2]);

	logger('key details: ' . print_r($key_info,true), LOGGER_DATA);
	$salmon_key = metopem($m,$e);
	return $salmon_key;

}


function z_obscure($s) {
	return json_encode(crypto_encapsulate($s,get_config('system','pubkey')));
}

function z_unobscure($s) {
	if(strpos($s,"{\"") !== 0)
		return $s;
	return crypto_unencapsulate(json_decode($s,true),get_config('system','prvkey'));
}