clean up the salmon consumer bits

include/salmon.php

@@ -43,25 +43,24 @@ function get_salmon_key($uri,$keyhash) {
 		$a = get_app();
 		$h = $a->get_curl_headers();
 		if($debugging)
-			file_put_contents('salmon.out', "\n" . 'Fetch key via HTML header: ' . $h . "\n", FILE_APPEND);
+			file_put_contents('salmon.out', "\n" . 'Fetch key via HTTP header: ' . $h . "\n", FILE_APPEND);
 
 		$l = explode("\n",$h);
 		if(count($l)) {
 			foreach($l as $line) {				
-				
-				if($debugging)
-					file_put_contents('salmon.out', "\n" . $line . "\n", FILE_APPEND);
 				if((stristr($line,'link:')) && preg_match('/<([^>].*)>.*rel\=[\'\"]lrdd[\'\"]/',$line,$matches)) {
 					$link = $matches[1];
 					if($debugging)
-						file_put_contents('salmon.out', "\n" . 'Fetch key via Link from header: ' . $link . "\n", FILE_APPEND);
+						file_put_contents('salmon.out', "\n" . 'Fetch key via HTML Link: ' . $link . "\n", FILE_APPEND);
 					break;
 				}
 			}
 		}
-	}
 
 		if(! isset($link)) {
+
+			// parse the page of the supplied URL looking for rel links
+
 			require_once('library/HTML5/Parser.php');
 			$dom = HTML5_Parser::parse($html);
 
@@ -85,6 +84,7 @@ function get_salmon_key($uri,$keyhash) {
 			return '';
 
 		$arr = fetch_xrd_links($link);
+	}
 
 	if($arr) {
 		foreach($arr as $a) {
@@ -93,6 +93,13 @@ function get_salmon_key($uri,$keyhash) {
 			}
 		}
 	}
+	else {
+		return '';
+	}
+
+	// We have found at least one key URL
+	// If it's inline, parse it - otherwise get the key
+
 	if(count($ret)) {
 		for($x = 0; $x < count($ret); $x ++) {
 			if(substr($ret[$x],0,5) === 'data:') {
@@ -105,10 +112,18 @@ function get_salmon_key($uri,$keyhash) {
 				$ret[$x] = fetch_url($ret[$x]);
 		}
 	}
+
 	if($debugging)
 		file_put_contents('salmon.out', "\n" . 'Key located: ' . print_r($ret,true) . "\n", FILE_APPEND);
 
 	if(count($ret) == 1) {
+
+		// We only found one one key so we don't care if the hash matches.
+		// If it's the wrong key we'll find out soon enough because 
+		// message verification will fail. This also covers some older 
+		// software which don't supply a keyhash. As long as they only
+		// have one key we'll be right. 
+
 		return $ret[0];
 	}
 	else {

mod/salmon.php

@@ -1,7 +1,7 @@
 <?php
 
 
-// TODO: pass keyhash to key discovery
+// TODO: 
 // add relevant contacts so they can use this
 
 // There is a lot of debug stuff in here because this is quite a
@@ -68,24 +68,30 @@ function salmon_post(&$a) {
 
 
 	$signature = base64url_decode($base->sig);
+
 	if($debugging)
 		file_put_contents('salmon.out', "\n" . 'Encoded Signature: ' . $base->sig . "\n" , FILE_APPEND);
 
-	// unpack our data element.
+	// unpack the  data
 
-	// strip whitespace
+	// strip whitespace so our data element will return to one big base64 blob
 	$data = str_replace(array(" ","\t","\r","\n"),array("","","",""),$base->data);
+
+	// stash away some other stuff for later
+
 	$type = $base->data[0]->attributes()->type[0];
+	$keyhash = $base->sig[0]->attributes()->keyhash[0];
 	$encoding = $base->encoding;
 	$alg = $base->alg;
 
-	$signed_data = $data;
+	// If we're talking to status.net or one of their ilk, they aren't following the magic envelope spec
-	// . '.' . base64url_encode($type) . '.' . base64url_encode($encoding) . '.' . base64url_encode($alg);
+	// and only signed the data element. We'll be nice and let them validate anyway. 
-	// decode it
-	$data = base64url_decode($data);
 
-	if($debugging)
+	$stnet_signed_data = $data;
-		file_put_contents('salmon.out', "\n" . 'Signed data:>>>' . $signed_data . "<<<\n" , FILE_APPEND);
+	$signed_data = $data  . '.' . base64url_encode($type) . '.' . base64url_encode($encoding) . '.' . base64url_encode($alg);
+
+	// decode the data
+	$data = base64url_decode($data);
 
 	// Remove the xml declaration
 	$data = preg_replace('/\<\?xml[^\?].*\?\>/','',$data);
@@ -128,7 +134,7 @@ function salmon_post(&$a) {
 		salmon_return(500);
 	}
 
-	// Once we have the author URI, go to the web and find their public key
+	// Once we have the author URI, go to the web and try to find their public key
 
 	if($debugging) {
 		file_put_contents('salmon.out', "\n" . 'Fetching key for ' . $author_link . "\n", FILE_APPEND);
@@ -152,6 +158,7 @@ function salmon_post(&$a) {
 
 	$m = base64url_decode($key_info[1]);
 	$e = base64url_decode($key_info[2]);
+
 	if($debugging)
 		file_put_contents('salmon.out',"\n" . print_r($key_info,true) . "\n", FILE_APPEND);
 
@@ -164,9 +171,14 @@ function salmon_post(&$a) {
     $rsa->exponent = new Math_BigInteger($e, 256);
 
 	// We should have everything we need now. Let's see if it verifies.
+	// If it fails with the proper data format, try again using just the data
+	// (e.g. status.net)
 
     $verify = $rsa->verify($signed_data,$signature);
 
+	if(! $verify)
+	    $verify = $rsa->verify($stnet_signed_data,$signature);
+
 	if(! $verify) {
 		if($debugging)
 			file_put_contents('salmon.out',"\n" . 'Message did not verify. Discarding.' . "\n", FILE_APPEND);
@@ -193,9 +205,11 @@ function salmon_post(&$a) {
 		salmon_return(500);
 	}	
 
-
 	require_once('include/items.php');
 
+	// Placeholder for hub discovery. We shouldn't find any hubs
+	// since we supplied the fake feed header - and it doesn't have any.
+
 	$hub = '';
 
 	consume_feed($feedxml,$importer,$r[0],$hub);