return 'RSA' . '.' . $m . '.' . $e ;
}
+
+
+function base64url_encode($s, $strip_padding = false) {
+
+ $s = strtr(base64_encode($s),'+/','-_');
+
+ if($strip_padding)
+ $s = str_replace('=','',$s);
+
+ return $s;
+}
+
+function base64url_decode($s) {
+
+/*
+ * // Placeholder for new rev of salmon which strips base64 padding.
+ * // PHP base64_decode handles the un-padded input without requiring this step
+ * // Uncomment if you find you need it.
+ *
+ * $l = strlen($s);
+ * if(! strpos($s,'=')) {
+ * $m = $l % 4;
+ * if($m == 2)
+ * $s .= '==';
+ * if($m == 3)
+ * $s .= '=';
+ * }
+ *
+ */
+
+ return base64_decode(strtr($s,'-_','+/'));
+}
+
+function get_salmon_key($uri,$keyhash) {
+ $ret = array();
+
+ logger('Fetching salmon key');
+
+ $arr = lrdd($uri);
+
+ if(is_array($arr)) {
+ foreach($arr as $a) {
+ if($a['@attributes']['rel'] === 'magic-public-key') {
+ $ret[] = $a['@attributes']['href'];
+ }
+ }
+ }
+ else {
+ return '';
+ }
+
+ // We have found at least one key URL
+ // If it's inline, parse it - otherwise get the key
+
+ if(count($ret)) {
+ for($x = 0; $x < count($ret); $x ++) {
+ if(substr($ret[$x],0,5) === 'data:') {
+ if(strstr($ret[$x],','))
+ $ret[$x] = substr($ret[$x],strpos($ret[$x],',')+1);
+ else
+ $ret[$x] = substr($ret[$x],5);
+ }
+ else
+ $ret[$x] = fetch_url($ret[$x]);
+ }
+ }
+
+
+ logger('Key located: ' . print_r($ret,true));
+
+ if(count($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 $ret[0];
+ }
+ else {
+ foreach($ret as $a) {
+ $hash = base64url_encode(hash('sha256',$a));
+ if($hash == $keyhash)
+ return $a;
+ }
+ }
+
+ return '';
+}
+
+
+
+function slapper($owner,$url,$slap) {
+
+ logger('slapper called. Data: ' . $slap);
+
+ // does contact have a salmon endpoint?
+
+ if(! strlen($url))
+ return;
+
+ // add all namespaces to item
+
+$namespaces = <<< EOT
+<entry xmlns="http://www.w3.org/2005/Atom"
+ xmlns:thr="http://purl.org/syndication/thread/1.0"
+ xmlns:at="http://purl.org/atompub/tombstones/1.0"
+ xmlns:media="http://purl.org/syndication/atommedia"
+ xmlns:dfrn="http://purl.org/macgirvin/dfrn/1.0"
+ xmlns:as="http://activitystrea.ms/spec/1.0/"
+ xmlns:georss="http://www.georss.org/georss"
+ xmlns:poco="http://portablecontacts.net/spec/1.0"
+ xmlns:ostatus="http://ostatus.org/schema/1.0" >
+EOT;
+
+ $slap = str_replace('<entry>',$namespaces,$slap);
+
+ // create a magic envelope
+
+ $data = base64url_encode($slap);
+ $data_type = 'application/atom+xml';
+ $encoding = 'base64url';
+ $algorithm = 'RSA-SHA256';
+ $keyhash = base64url_encode(hash('sha256',salmon_key($owner['spubkey'])));
+
+ // Setup RSA stuff to PKCS#1 sign the data
+
+ set_include_path(get_include_path() . PATH_SEPARATOR . 'phpsec');
+
+ require_once('phpsec/Crypt/RSA.php');
+
+ $rsa = new CRYPT_RSA();
+ $rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1;
+ $rsa->setHash('sha256');
+ $rsa->loadKey($owner['sprvkey']);
+
+ // precomputed base64url encoding of data_type, encoding, algorithm concatenated with periods
+
+ $precomputed = '.YXBwbGljYXRpb24vYXRvbSt4bWw=.YmFzZTY0dXJs.UlNBLVNIQTI1Ng==';
+
+ $signature = base64url_encode($rsa->sign($data . $precomputed));
+
+ $signature2 = base64url_encode($rsa->sign($data));
+
+ $salmon_tpl = load_view_file('view/magicsig.tpl');
+ $salmon = replace_macros($salmon_tpl,array(
+ '$data' => $data,
+ '$encoding' => $encoding,
+ '$algorithm' => $algorithm,
+ '$keyhash' => $keyhash,
+ '$signature' => $signature
+ ));
+
+ // slap them
+ post_url($url,$salmon, array(
+ 'Content-type: application/magic-envelope+xml',
+ 'Content-length: ' . strlen($salmon)
+ ));
+
+ $a = get_app();
+ $return_code = $a->get_curl_code();
+
+ // check for success, e.g. 2xx
+
+ if($return_code > 299) {
+
+ logger('slapper: compliant salmon failed. Falling back to status.net hack');
+
+ // Entirely likely that their salmon implementation is
+ // non-compliant. Let's try once more, this time only signing
+ // the data, without the precomputed blob
+
+ $salmon = replace_macros($salmon_tpl,array(
+ '$data' => $data,
+ '$encoding' => $encoding,
+ '$algorithm' => $algorithm,
+ '$keyhash' => $keyhash,
+ '$signature' => $signature2
+ ));
+
+ // slap them
+ post_url($url,$salmon, array(
+ 'Content-type: application/magic-envelope+xml',
+ 'Content-length: ' . strlen($salmon)
+ ));
+ $return_code = $a->get_curl_code();
+
+ }
+ logger('slapper returned ' . $return_code);
+ if(! $return_code)
+ return(-1);
+ return ((($return_code >= 200) && ($return_code < 300)) ? 0 : 1);
+}
+
projects / friendica.git / blobdiff