A bit more telemetry of friend confirms and lots of extra doco

to understand what is happening and why.

1 files changed, 270 insertions, 211 deletions

diff --git a/mod/dfrn_confirm.php b/mod/dfrn_confirm.php
index 7daa7f944..7c24de87d 100644
--- a/mod/dfrn_confirm.php
+++ b/mod/dfrn_confirm.php
@@ -1,217 +1,17 @@
 <?php
 
-
+// There are two possible entry points. Both are called via POST.
 
 function dfrn_confirm_post(&$a) {
 
 	if($a->argc > 1)
 		$node = $a->argv[1];
 
-	if(x($_POST,'source_url')) {
-
-		// We are processing an external confirmation to an introduction created by our user.
-
-		$public_key = $_POST['public_key'];
-		$dfrn_id    = $_POST['dfrn_id'];
-		$source_url = $_POST['source_url'];
-		$aes_key    = $_POST['aes_key'];
-		$duplex     = $_POST['duplex'];
-		$version_id = $_POST['dfrn_version'];
-
-		// Find our user's account
-
-		$r = q("SELECT * FROM `user` WHERE `nickname` = '%s' LIMIT 1",
-			dbesc($node));
-
-		if(! count($r)) {
-			$message = t('No user record found for ') . '\'' . $node . '\'';
-			xml_status(3,$message); // failure
-			// NOTREACHED
-		}
-
-		$my_prvkey = $r[0]['prvkey'];
-		$local_uid = $r[0]['uid'];
-
-
-		if(! strstr($my_prvkey,'BEGIN RSA PRIVATE KEY')) {
-			$message = t('Our site encryption key is apparently messed up.');
-			xml_status(3,$message);
-		}
-
-		// verify everything
-
-		$decrypted_source_url = "";
-		openssl_private_decrypt($source_url,$decrypted_source_url,$my_prvkey);
-
-
-		if(! strlen($decrypted_source_url)) {
-			$message = t('Empty site URL was provided or URL could not be decrypted by us.');
-			xml_status(3,$message);
-			// NOTREACHED
-		}
-
-		$ret = q("SELECT * FROM `contact` WHERE `url` = '%s' AND `uid` = %d LIMIT 1",
-			dbesc($decrypted_source_url),
-			intval($local_uid)
-		);
-
-		if(! count($ret)) {
-			// this is either a bogus confirmation (?) or we deleted the original introduction.
-			$message = t('Contact record was not found for you on our site.');
-			xml_status(3,$message);
-			return; // NOTREACHED 
-		}
-
-		$relation = $ret[0]['rel'];
-
-		// Decrypt all this stuff we just received
-
-		$foreign_pubkey = $ret[0]['site-pubkey'];
-		$dfrn_record    = $ret[0]['id'];
-
-		$decrypted_dfrn_id = "";
-		openssl_public_decrypt($dfrn_id,$decrypted_dfrn_id,$foreign_pubkey);
-
-		if(strlen($aes_key)) {
-			$decrypted_aes_key = "";
-			openssl_private_decrypt($aes_key,$decrypted_aes_key,$my_prvkey);
-			$dfrn_pubkey = openssl_decrypt($public_key,'AES-256-CBC',$decrypted_aes_key);
-		}
-		else {
-			$dfrn_pubkey = $public_key;
-		}
-
-		$r = q("SELECT * FROM `contact` WHERE `dfrn-id` = '%s' LIMIT 1",
-			dbesc($decrypted_dfrn_id),
-			intval($local_uid)
-		);
-		if(count($r)) {
-			$message = t('The ID provided by your system is a duplicate on our system. It should work if you try again.');
-			xml_status(1,$message); // Birthday paradox - duplicate dfrn-id
-			// NOTREACHED
-		}
-
-		$r = q("UPDATE `contact` SET `dfrn-id` = '%s', `pubkey` = '%s' WHERE `id` = %d LIMIT 1",
-			dbesc($decrypted_dfrn_id),
-			dbesc($dfrn_pubkey),
-			intval($dfrn_record)
-		);
-		if(! count($r)) {
-			$message = t('Unable to set your contact credentials on our system.');
-			xml_status(3,$message);
-		}
-
-		// We're good but now we have to scrape the profile photo and send notifications.
-
-		require_once("Photo.php");
-
-		$photo_failure = false;
-
-		$r = q("SELECT `photo` FROM `contact` WHERE `id` = %d LIMIT 1",
-			intval($dfrn_record));
-		if(count($r)) {
-
-			$filename = basename($r[0]['photo']);
-			$img_str = fetch_url($r[0]['photo'],true);
-			$img = new Photo($img_str);
-			if($img->is_valid()) {
-
-				$img->scaleImageSquare(175);
-					
-				$hash = photo_new_resource();
-
-				$r = $img->store($local_uid, $dfrn_record, $hash, $filename, t('Contact Photos') , 4);
-
-				if($r === false)
-					$photo_failure = true;
-					
-				$img->scaleImage(80);
-				$r = $img->store($local_uid, $dfrn_record, $hash, $filename, t('Contact Photos') , 5);
-
-				if($r === false)
-					$photo_failure = true;
-
-				$photo = $a->get_baseurl() . '/photo/' . $hash . '-4.jpg';
-				$thumb = $a->get_baseurl() . '/photo/' . $hash . '-5.jpg';	
-			}
-			else
-				$photo_failure = true;
-		}
-		else
-			$photo_failure = true;
-
-		if($photo_failure) {
-			$photo = $a->get_baseurl() . '/images/default-profile.jpg';
-			$thumb = $a->get_baseurl() . '/images/default-profile-sm.jpg';
-		}
-
-		$new_relation = REL_FAN;
-		if(($relation == REL_VIP) || ($duplex))
-			$new_relation = REL_BUD;
-
-		$r = q("UPDATE `contact` SET 
-			`photo` = '%s', 
-			`thumb` = '%s', 
-			`rel` = %d, 
-			`name-date` = '%s', 
-			`uri-date` = '%s', 
-			`avatar-date` = '%s', 
-			`blocked` = 0, 
-			`pending` = 0,
-			`duplex` = %d, 
-			`network` = 'dfrn' WHERE `id` = %d LIMIT 1
-		",
-			dbesc($photo),
-			dbesc($thumb),
-			intval($new_relation),
-			dbesc(datetime_convert()),
-			dbesc(datetime_convert()),
-			dbesc(datetime_convert()),
-			intval($duplex),
-			intval($dfrn_record)
-		);
-		if($r === false) { // should not happen unless schema is messed up
-			$message = t('Unable to update your contact profile details on our system');
-			xml_status(3,$message);
-		}
-
-		// Otherwise everything seems to have worked and we are almost done. Yay!
-		// Send an email notification
+		// Main entry point. Our user received a friend request notification (perhaps 
+		// from another site) and clicked 'Accept'. $POST['source_url'] is not set.
+		// They will perform the following:
 
-		$r = q("SELECT * FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
-			WHERE `contact`.`id` = %d LIMIT 1",
-			intval($dfrn_record)
-		);
-		if((count($r)) && ($r[0]['notify-flags'] & NOTIFY_CONFIRM)) {
-
-			$tpl = (($new_relation == REL_BUD) 
-				? load_view_file('view/friend_complete_eml.tpl')
-				: load_view_file('view/intro_complete_eml.tpl'));
-		
-			$email_tpl = replace_macros($tpl, array(
-				'$sitename' => $a->config['sitename'],
-				'$siteurl' =>  $a->get_baseurl(),
-				'$username' => $r[0]['username'],
-				'$email' => $r[0]['email'],
-				'$fn' => $r[0]['name'],
-				'$dfrn_url' => $r[0]['url'],
-				'$uid' => $newuid )
-			);
-	
-			$res = mail($r[0]['email'], t("Connection accepted at ") . $a->config['sitename'],
-				$email_tpl, 'From: ' . t('Administrator') . '@' . $_SERVER[SERVER_NAME] );
-			if(!$res) {
-				notice( t("Email notification failed.") . EOL );
-			}
-		}
-		xml_status(0); // Success
-		return; // NOTREACHED
-
-	////////////////////// End of this scenario ///////////////////////////////////////////////
-	}
-	else {
-
-		// We are processing a local confirmation initiated on this system by our user to an external introduction.
+	if(! x($_POST,'source_url')) {
 
 		$uid = get_uid();
 
@@ -219,18 +19,24 @@ function dfrn_confirm_post(&$a) {
 			notice( t('Permission denied.') . EOL );
 			return;
 		}	
+
+		// These come from the friend request notification form.
 	
 		$dfrn_id  = ((x($_POST,'dfrn_id')) ? notags(trim($_POST['dfrn_id'])) : "");
 		$intro_id = intval($_POST['intro_id']);
 		$duplex   = intval($_POST['duplex']);
 
+
+		// The other person will have been issued an ID when they first requested friendship.
+		// Locate their record. At this time, their record will have both pending and blocked set to 1. 
+
 		$r = q("SELECT * FROM `contact` WHERE `issued-id` = '%s' AND `uid` = %d LIMIT 1",
 				dbesc($dfrn_id),
 				intval($uid)
 		);
 
 		if(! count($r)) {
-			notice( t('Node does not exist.') . EOL );
+			notice( t('Contact not found.') . EOL );
 			return;
 		}
 
@@ -240,6 +46,13 @@ function dfrn_confirm_post(&$a) {
 		$dfrn_confirm = $r[0]['confirm'];
 		$aes_allow    = $r[0]['aes_allow'];
 
+
+		// Generate a key pair for all further communications with this person.
+		// We have a keypair for every contact, and a site key for unknown people.
+		// This provides a means to carry on relationships with other people if 
+		// any single key is compromised. It is a robust key. We're much more 
+		// worried about key leakage than anybody cracking it.  
+
 		$res = openssl_pkey_new(array(
         		'digest_alg' => 'whirlpool',
         		'private_key_bits' => 4096,
@@ -254,6 +67,8 @@ function dfrn_confirm_post(&$a) {
 		$pubkey = openssl_pkey_get_details($res);
 		$public_key = $pubkey["key"];
 
+		// Save the private key. Send them the public key.
+
 		$r = q("UPDATE `contact` SET `prvkey` = '%s' WHERE `id` = %d AND `uid` = %d LIMIT 1",
 			dbesc($private_key),
 			intval($contact_id),
@@ -263,6 +78,21 @@ function dfrn_confirm_post(&$a) {
 
 		$params = array();
 
+		// Per the protocol document, we will verify both ends by encrypting the dfrn_id with our 
+		// site private key (person on the other end can decrypt it with our site public key).
+		// Then encrypt our profile URL with the other person's site public key. They can decrypt
+		// it with their site private key. If the decryption on the other end fails for either
+		// item, it indicates tampering or key failure on at least one site and we will not be 
+		// able to provide a secure communication pathway.
+
+		// If other site is willing to accept full encryption, (aes_allow is 1 AND we have php5.3 
+		// or later) then we encrypt the personal public key we send them using AES-256-CBC and a 
+		// random key which is encrypted with their site public key.  
+
+		// Note: We can send any of these things as binary blobs because they are being POST'ed.
+		// Any protocol conversations (notify, poll) which perform GET require bin2hex of all the 
+		// binary stuff. 
+
 		$src_aes_key = random_string();
 
 		$result = '';
@@ -285,10 +115,12 @@ function dfrn_confirm_post(&$a) {
 		if($duplex == 1)
 			$params['duplex'] = 1;
 
+		// POST all this stuff to the other site.
+
 		$res = post_url($dfrn_confirm,$params);
 
-		// Try to be robust if the remote site is having difficulty and throwing up
-		// errors of some kind. 
+		// Now figure out what they responded. Try to be robust if the remote site is 
+		// having difficulty and throwing up errors of some kind. 
 
 		$leading_junk = substr($res,0,strpos($res,'<?xml'));
 
@@ -314,7 +146,7 @@ function dfrn_confirm_post(&$a) {
 
 		$xml = simplexml_load_string($res);
 		$status = (int) $xml->status;
-		$message = unxmlify($xml->message);
+		$message = unxmlify($xml->message);   // human readable text of what may have gone wrong.
 		switch($status) {
 			case 0:
 				notice( t("Confirmation completed successfully.") . EOL);
@@ -346,7 +178,7 @@ function dfrn_confirm_post(&$a) {
 
 		if(($status == 0) && ($intro_id)) {
 
-			//delete the notification
+			// Success. Delete the notification.
 
 			$r = q("DELETE FROM `intro` WHERE `id` = %d AND `uid` = %d LIMIT 1",
 				intval($intro_id),
@@ -358,6 +190,10 @@ function dfrn_confirm_post(&$a) {
 		if($status != 0) 
 			return;
 		
+		// We have now established a relationship with the other site.
+		// Let's make our own personal copy of their profile photo so we don't have
+		// to always load it from their site.
+
 		require_once("Photo.php");
 
 		$photo_failure = false;
@@ -428,8 +264,231 @@ function dfrn_confirm_post(&$a) {
 		if($r === false)
 			notice( t('Unable to set contact photo.') . EOL);
 
+
+		// Let's send our user to the contact editor in case they want to
+		// do anything special with this new friend.
+ 
 		goaway($a->get_baseurl() . '/contacts/' . intval($contact_id));
 		return;  //NOTREACHED
 	}
-	return;
+
+
+
+	// End of first scenario. [Local confirmation of remote friend request].
+
+
+
+	// Begin scenario two. This is the remote response to the above scenario.
+	// This will take place on the site that originally initiated the friend request.
+	// In the section above where the confirming party makes a POST and 
+	// retrieves xml status information, they are communicating with the following code.
+
+	if(x($_POST,'source_url')) {
+
+		// We are processing an external confirmation to an introduction created by our user.
+
+		$public_key = $_POST['public_key'];
+		$dfrn_id    = $_POST['dfrn_id'];
+		$source_url = $_POST['source_url'];
+		$aes_key    = $_POST['aes_key'];
+		$duplex     = $_POST['duplex'];
+		$version_id = $_POST['dfrn_version'];
+
+		// Find our user's account
+
+		$r = q("SELECT * FROM `user` WHERE `nickname` = '%s' LIMIT 1",
+			dbesc($node));
+
+		if(! count($r)) {
+			$message = t('No user record found for ') . '\'' . $node . '\'';
+			xml_status(3,$message); // failure
+			// NOTREACHED
+		}
+
+		$my_prvkey = $r[0]['prvkey'];
+		$local_uid = $r[0]['uid'];
+
+
+		if(! strstr($my_prvkey,'BEGIN RSA PRIVATE KEY')) {
+			$message = t('Our site encryption key is apparently messed up.');
+			xml_status(3,$message);
+		}
+
+		// verify everything
+
+		$decrypted_source_url = "";
+		openssl_private_decrypt($source_url,$decrypted_source_url,$my_prvkey);
+
+
+		if(! strlen($decrypted_source_url)) {
+			$message = t('Empty site URL was provided or URL could not be decrypted by us.');
+			xml_status(3,$message);
+			// NOTREACHED
+		}
+
+		$ret = q("SELECT * FROM `contact` WHERE `url` = '%s' AND `uid` = %d LIMIT 1",
+			dbesc($decrypted_source_url),
+			intval($local_uid)
+		);
+
+		if(! count($ret)) {
+			// this is either a bogus confirmation (?) or we deleted the original introduction.
+			$message = t('Contact record was not found for you on our site.');
+			xml_status(3,$message);
+			return; // NOTREACHED 
+		}
+
+		$relation = $ret[0]['rel'];
+
+		// Decrypt all this stuff we just received
+
+		$foreign_pubkey = $ret[0]['site-pubkey'];
+		$dfrn_record    = $ret[0]['id'];
+
+		$decrypted_dfrn_id = "";
+		openssl_public_decrypt($dfrn_id,$decrypted_dfrn_id,$foreign_pubkey);
+
+		if(strlen($aes_key)) {
+			$decrypted_aes_key = "";
+			openssl_private_decrypt($aes_key,$decrypted_aes_key,$my_prvkey);
+			$dfrn_pubkey = openssl_decrypt($public_key,'AES-256-CBC',$decrypted_aes_key);
+		}
+		else {
+			$dfrn_pubkey = $public_key;
+		}
+
+		$r = q("SELECT * FROM `contact` WHERE `dfrn-id` = '%s' LIMIT 1",
+			dbesc($decrypted_dfrn_id),
+			intval($local_uid)
+		);
+		if(count($r)) {
+			$message = t('The ID provided by your system is a duplicate on our system. It should work if you try again.');
+			xml_status(1,$message); // Birthday paradox - duplicate dfrn-id
+			// NOTREACHED
+		}
+
+		$r = q("UPDATE `contact` SET `dfrn-id` = '%s', `pubkey` = '%s' WHERE `id` = %d LIMIT 1",
+			dbesc($decrypted_dfrn_id),
+			dbesc($dfrn_pubkey),
+			intval($dfrn_record)
+		);
+		if(! count($r)) {
+			$message = t('Unable to set your contact credentials on our system.');
+			xml_status(3,$message);
+		}
+
+		// We're good but now we have to scrape the profile photo and send notifications.
+
+		require_once("Photo.php");
+
+		$photo_failure = false;
+
+		$r = q("SELECT `photo` FROM `contact` WHERE `id` = %d LIMIT 1",
+			intval($dfrn_record));
+		if(count($r)) {
+
+			$filename = basename($r[0]['photo']);
+			$img_str = fetch_url($r[0]['photo'],true);
+			$img = new Photo($img_str);
+			if($img->is_valid()) {
+
+				$img->scaleImageSquare(175);
+					
+				$hash = photo_new_resource();
+
+				$r = $img->store($local_uid, $dfrn_record, $hash, $filename, t('Contact Photos') , 4);
+
+				if($r === false)
+					$photo_failure = true;
+					
+				$img->scaleImage(80);
+				$r = $img->store($local_uid, $dfrn_record, $hash, $filename, t('Contact Photos') , 5);
+
+				if($r === false)
+					$photo_failure = true;
+
+				$photo = $a->get_baseurl() . '/photo/' . $hash . '-4.jpg';
+				$thumb = $a->get_baseurl() . '/photo/' . $hash . '-5.jpg';	
+			}
+			else
+				$photo_failure = true;
+		}
+		else
+			$photo_failure = true;
+
+		if($photo_failure) {
+			$photo = $a->get_baseurl() . '/images/default-profile.jpg';
+			$thumb = $a->get_baseurl() . '/images/default-profile-sm.jpg';
+		}
+
+		$new_relation = REL_FAN;
+		if(($relation == REL_VIP) || ($duplex))
+			$new_relation = REL_BUD;
+
+		$r = q("UPDATE `contact` SET 
+			`photo` = '%s', 
+			`thumb` = '%s', 
+			`rel` = %d, 
+			`name-date` = '%s', 
+			`uri-date` = '%s', 
+			`avatar-date` = '%s', 
+			`blocked` = 0, 
+			`pending` = 0,
+			`duplex` = %d, 
+			`network` = 'dfrn' WHERE `id` = %d LIMIT 1
+		",
+			dbesc($photo),
+			dbesc($thumb),
+			intval($new_relation),
+			dbesc(datetime_convert()),
+			dbesc(datetime_convert()),
+			dbesc(datetime_convert()),
+			intval($duplex),
+			intval($dfrn_record)
+		);
+		if($r === false) { // indicates schema is messed up or total db failure
+			$message = t('Unable to update your contact profile details on our system');
+			xml_status(3,$message);
+		}
+
+		// Otherwise everything seems to have worked and we are almost done. Yay!
+		// Send an email notification
+
+		$r = q("SELECT * FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
+			WHERE `contact`.`id` = %d LIMIT 1",
+			intval($dfrn_record)
+		);
+		if((count($r)) && ($r[0]['notify-flags'] & NOTIFY_CONFIRM)) {
+
+			$tpl = (($new_relation == REL_BUD) 
+				? load_view_file('view/friend_complete_eml.tpl')
+				: load_view_file('view/intro_complete_eml.tpl'));
+		
+			$email_tpl = replace_macros($tpl, array(
+				'$sitename' => $a->config['sitename'],
+				'$siteurl' =>  $a->get_baseurl(),
+				'$username' => $r[0]['username'],
+				'$email' => $r[0]['email'],
+				'$fn' => $r[0]['name'],
+				'$dfrn_url' => $r[0]['url'],
+				'$uid' => $newuid )
+			);
+	
+			$res = mail($r[0]['email'], t("Connection accepted at ") . $a->config['sitename'],
+				$email_tpl, 'From: ' . t('Administrator') . '@' . $_SERVER[SERVER_NAME] );
+			if(!$res) {
+				notice( t("Email notification failed.") . EOL );
+			}
+		}
+		xml_status(0); // Success
+		return; // NOTREACHED
+
+			////////////////////// End of this scenario ///////////////////////////////////////////////
+	}
+
+	// somebody arrived here by mistake or they are fishing. Send them to the homepage.
+
+	goaway($a->get_baseurl());
+	// NOTREACHED
+
 }