Salmon signature checks on incoming slaps now check both old and new signature formats.

[quix0rs-gnu-social.git] / plugins / OStatus / lib / salmon.php

diff --git a/plugins/OStatus/lib/salmon.php b/plugins/OStatus/lib/salmon.php
index ef7719a40c3861513549b11dc6096e89d25d56b5..2f5772a84497eac45d0cf86cdb73faea50899301 100644 (file)
--- a/plugins/OStatus/lib/salmon.php
+++ b/plugins/OStatus/lib/salmon.php
@@ -31,17 +31,19 @@ class Salmon
     const REL_SALMON = 'salmon';
     const REL_MENTIONED = 'mentioned';
 
-    // XXX: these are deprecated 
+    // XXX: these are deprecated
     const NS_REPLIES = "http://salmon-protocol.org/ns/salmon-replies";
     const NS_MENTIONS = "http://salmon-protocol.org/ns/salmon-mention";
-    
+
     /**
      * Sign and post the given Atom entry as a Salmon message.
      *
-     * @fixme pass through the actor for signing?
+     * Side effects: may generate a keypair on-demand for the given user,
+     * which can be very slow on some systems.
      *
      * @param string $endpoint_uri
-     * @param string $xml
+     * @param string $xml string representation of payload
+     * @param Profile $actor local user profile whose keys to sign with
      * @return boolean success
      */
     public function post($endpoint_uri, $xml, $actor)
@@ -50,34 +52,65 @@ class Salmon
             return false;
         }
 
-        try {
-            $xml = $this->createMagicEnv($xml, $actor);
-        } catch (Exception $e) {
-            common_log(LOG_ERR, "Salmon unable to sign: " . $e->getMessage());
-            return false;
-        }
-
-        $headers = array('Content-Type: application/magic-envelope+xml');
+        foreach ($this->formatClasses() as $class) {
+            try {
+                $envelope = $this->createMagicEnv($xml, $actor, $class);
+            } catch (Exception $e) {
+                common_log(LOG_ERR, "Salmon unable to sign: " . $e->getMessage());
+                return false;
+            }
+    
+            $headers = array('Content-Type: application/magic-envelope+xml');
+    
+            try {
+                $client = new HTTPClient();
+                $client->setBody($envelope);
+                $response = $client->post($endpoint_uri, $headers);
+            } catch (HTTP_Request2_Exception $e) {
+                common_log(LOG_ERR, "Salmon ($class) post to $endpoint_uri failed: " . $e->getMessage());
+                continue;
+            }
+            if ($response->getStatus() != 200) {
+                common_log(LOG_ERR, "Salmon ($class) at $endpoint_uri returned status " .
+                    $response->getStatus() . ': ' . $response->getBody());
+                continue;
+            }
 
-        try {
-            $client = new HTTPClient();
-            $client->setBody($xml);
-            $response = $client->post($endpoint_uri, $headers);
-        } catch (HTTP_Request2_Exception $e) {
-            common_log(LOG_ERR, "Salmon post to $endpoint_uri failed: " . $e->getMessage());
-            return false;
-        }
-        if ($response->getStatus() != 200) {
-            common_log(LOG_ERR, "Salmon at $endpoint_uri returned status " .
-                $response->getStatus() . ': ' . $response->getBody());
-            return false;
+            // Success!
+            return true;
         }
-        return true;
+        return false;
+    }
+
+    /**
+     * List the magic envelope signature class variants in the order we try them.
+     * Multiples are needed for backwards-compat with StatusNet prior to 0.9.7,
+     * which used a draft version of the magic envelope spec.
+     */
+    protected function formatClasses() {
+        return array('MagicEnvelope', 'MagicEnvelopeCompat');
     }
 
-    public function createMagicEnv($text, $actor)
+    /**
+     * Encode the given string as a signed MagicEnvelope XML document,
+     * using the keypair for the given local user profile.
+     *
+     * Side effects: will create and store a keypair on-demand if one
+     * hasn't already been generated for this user. This can be very slow
+     * on some systems.
+     *
+     * @param string $text XML fragment to sign, assumed to be Atom
+     * @param Profile $actor Profile of a local user to use as signer
+     * @param string $class to override the magic envelope signature version, pass a MagicEnvelope subclass here
+     *
+     * @return string XML string representation of magic envelope
+     *
+     * @throws Exception on bad profile input or key generation problems
+     * @fixme if signing fails, this seems to return the original text without warning. Is there a reason for this?
+     */
+    public function createMagicEnv($text, $actor, $class='MagicEnvelope')
     {
-        $magic_env = new MagicEnvelope();
+        $magic_env = new $class();
 
         $user = User::staticGet('id', $actor->id);
         if ($user->id) {
@@ -87,9 +120,10 @@ class Salmon
                 // No keypair yet, let's generate one.
                 $magickey = new Magicsig();
                 $magickey->generate($user->id);
-            } 
+            }
         } else {
-            throw new Exception("Salmon invalid actor for signing");
+            // TRANS: Exception.
+            throw new Exception(_m('Salmon invalid actor for signing.'));
         }
 
         try {
@@ -100,13 +134,32 @@ class Salmon
         return $magic_env->toXML($env);
     }
 
-
+    /**
+     * Check if the given magic envelope is well-formed and correctly signed.
+     * Needs to have network access to fetch public keys over the web.
+     * Both current and back-compat signature formats will be checked.
+     *
+     * Side effects: exceptions and caching updates may occur during network
+     * fetches.
+     *
+     * @param string $text XML fragment of magic envelope
+     * @return boolean
+     *
+     * @throws Exception on bad profile input or key generation problems
+     * @fixme could hit fatal errors or spew output on invalid XML
+     */
     public function verifyMagicEnv($text)
     {
-        $magic_env = new MagicEnvelope();
-        
-        $env = $magic_env->parse($text);
+        foreach ($this->formatClasses() as $class) {
+            $magic_env = new $class();
+
+            $env = $magic_env->parse($text);
+
+            if ($magic_env->verify($env)) {
+                return true;
+            }
+        }
 
-        return $magic_env->verify($env);
+        return false;
     }
 }