* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
* @link http://status.net/
*/
-
class MagicEnvelope
{
const ENCODING = 'base64url';
const NS = 'http://salmon-protocol.org/ns/magic-env';
-
+
private function normalizeUser($user_id)
{
if (substr($user_id, 0, 5) == 'http:' ||
} catch (Exception $e) {
return false;
}
- if ($xrd->links) {
- if ($link = Discovery::getService($xrd->links, Magicsig::PUBLICKEYREL)) {
- $keypair = false;
- $parts = explode(',', $link['href']);
+ $link = $xrd->get(Magicsig::PUBLICKEYREL);
+ if (!is_null($link)) {
+ $keypair = false;
+ $parts = explode(',', $link->href);
+ if (count($parts) == 2) {
+ $keypair = $parts[1];
+ } else {
+ // Backwards compatibility check for separator bug in 0.9.0
+ $parts = explode(';', $link->href);
if (count($parts) == 2) {
$keypair = $parts[1];
- } else {
- // Backwards compatibility check for separator bug in 0.9.0
- $parts = explode(';', $link['href']);
- if (count($parts) == 2) {
- $keypair = $parts[1];
- }
- }
-
- if ($keypair) {
- return $keypair;
}
}
+
+ if ($keypair) {
+ return $keypair;
+ }
}
- throw new Exception('Unable to locate signer public key');
+ // TRANS: Exception.
+ throw new Exception(_m('Unable to locate signer public key.'));
}
+ /**
+ * The current MagicEnvelope spec as used in StatusNet 0.9.7 and later
+ * includes both the original data and some signing metadata fields as
+ * the input plaintext for the signature hash.
+ *
+ * @param array $env
+ * @return string
+ */
+ public function signingText($env) {
+ return implode('.', array($env['data'], // this field is pre-base64'd
+ Magicsig::base64_url_encode($env['data_type']),
+ Magicsig::base64_url_encode($env['encoding']),
+ Magicsig::base64_url_encode($env['alg'])));
+ }
+ /**
+ *
+ * @param <type> $text
+ * @param <type> $mimetype
+ * @param <type> $keypair
+ * @return array: associative array of envelope properties
+ * @fixme it might be easier to work with storing envelope data these in the object instead of passing arrays around
+ */
public function signMessage($text, $mimetype, $keypair)
{
$signature_alg = Magicsig::fromString($keypair);
- $armored_text = base64_url_encode($text);
-
- return array(
+ $armored_text = Magicsig::base64_url_encode($text);
+ $env = array(
'data' => $armored_text,
'encoding' => MagicEnvelope::ENCODING,
'data_type' => $mimetype,
- 'sig' => $signature_alg->sign($armored_text),
+ 'sig' => '',
'alg' => $signature_alg->getName()
);
-
-
+
+ $env['sig'] = $signature_alg->sign($this->signingText($env));
+
+ return $env;
}
+ /**
+ * Create an <me:env> XML representation of the envelope.
+ *
+ * @param array $env associative array with envelope data
+ * @return string representation of XML document
+ * @fixme it might be easier to work with storing envelope data these in the object instead of passing arrays around
+ */
public function toXML($env) {
- $dom = new DOMDocument();
-
- $envelope = $dom->createElementNS(MagicEnvelope::NS, 'me:env');
- $envelope->setAttribute('xmlns:me', MagicEnvelope::NS);
- $data = $dom->createElementNS(MagicEnvelope::NS, 'me:data', $env['data']);
- $data->setAttribute('type', $env['data_type']);
- $envelope->appendChild($data);
- $enc = $dom->createElementNS(MagicEnvelope::NS, 'me:encoding', $env['encoding']);
- $envelope->appendChild($enc);
- $alg = $dom->createElementNS(MagicEnvelope::NS, 'me:alg', $env['alg']);
- $envelope->appendChild($alg);
- $sig = $dom->createElementNS(MagicEnvelope::NS, 'me:sig', $env['sig']);
- $envelope->appendChild($sig);
+ $xs = new XMLStringer();
+ $xs->startXML();
+ $xs->elementStart('me:env', array('xmlns:me' => MagicEnvelope::NS));
+ $xs->element('me:data', array('type' => $env['data_type']), $env['data']);
+ $xs->element('me:encoding', null, $env['encoding']);
+ $xs->element('me:alg', null, $env['alg']);
+ $xs->element('me:sig', null, $env['sig']);
+ $xs->elementEnd('me:env');
- $dom->appendChild($envelope);
-
-
- return $dom->saveXML();
+ $string = $xs->getString();
+ common_debug($string);
+ return $string;
}
-
+ /**
+ * Extract the contained XML payload, and insert a copy of the envelope
+ * signature data as an <me:provenance> section.
+ *
+ * @param array $env associative array with envelope data
+ * @return string representation of modified XML document
+ *
+ * @fixme in case of XML parsing errors, this will spew to the error log or output
+ * @fixme it might be easier to work with storing envelope data these in the object instead of passing arrays around
+ */
public function unfold($env)
{
$dom = new DOMDocument();
- $dom->loadXML(base64_url_decode($env['data']));
+ $dom->loadXML(Magicsig::base64_url_decode($env['data']));
if ($dom->documentElement->tagName != 'entry') {
return false;
return $dom->saveXML();
}
-
+
+ /**
+ * Find the author URI referenced in the given Atom entry.
+ *
+ * @param string $text string containing Atom entry XML
+ * @return mixed URI string or false if XML parsing fails, or null if no author URI can be found
+ *
+ * @fixme XML parsing failures will spew to error logs/output
+ */
public function getAuthor($text) {
$doc = new DOMDocument();
if (!$doc->loadXML($text)) {
}
}
}
-
+
+ /**
+ * Check if the author in the Atom entry fragment claims to match
+ * the given identifier URI.
+ *
+ * @param string $text string containing Atom entry XML
+ * @param string $signer_uri
+ * @return boolean
+ */
public function checkAuthor($text, $signer_uri)
{
return ($this->getAuthor($text) == $signer_uri);
}
-
+
+ /**
+ * Attempt to verify cryptographic signing for parsed envelope data.
+ * Requires network access to retrieve public key referenced by the envelope signer.
+ *
+ * Details of failure conditions are dumped to output log and not exposed to caller.
+ *
+ * @param array $env array representation of magic envelope data, as returned from MagicEnvelope::parse()
+ * @return boolean
+ *
+ * @fixme it might be easier to work with storing envelope data these in the object instead of passing arrays around
+ */
public function verify($env)
{
if ($env['alg'] != 'RSA-SHA256') {
return false;
}
- $text = base64_url_decode($env['data']);
+ $text = Magicsig::base64_url_decode($env['data']);
$signer_uri = $this->getAuthor($text);
try {
common_log(LOG_DEBUG, "Salmon error: ".$e->getMessage());
return false;
}
-
+
$verifier = Magicsig::fromString($keypair);
if (!$verifier) {
common_log(LOG_DEBUG, "Salmon error: unable to parse keypair");
return false;
}
-
- return $verifier->verify($env['data'], $env['sig']);
+
+ return $verifier->verify($this->signingText($env), $env['sig']);
}
+ /**
+ * Extract envelope data from an XML document containing an <me:env> or <me:provenance> element.
+ *
+ * @param string XML source
+ * @return mixed associative array of envelope data, or false on unrecognized input
+ *
+ * @fixme it might be easier to work with storing envelope data these in the object instead of passing arrays around
+ * @fixme will spew errors to logs or output in case of XML parse errors
+ * @fixme may give fatal errors if some elements are missing or invalid XML
+ * @fixme calling DOMDocument::loadXML statically triggers warnings in strict mode
+ */
public function parse($text)
{
$dom = DOMDocument::loadXML($text);
return $this->fromDom($dom);
}
+ /**
+ * Extract envelope data from an XML document containing an <me:env> or <me:provenance> element.
+ *
+ * @param DOMDocument $dom
+ * @return mixed associative array of envelope data, or false on unrecognized input
+ *
+ * @fixme it might be easier to work with storing envelope data these in the object instead of passing arrays around
+ * @fixme may give fatal errors if some elements are missing
+ */
public function fromDom($dom)
{
$env_element = $dom->getElementsByTagNameNS(MagicEnvelope::NS, 'env')->item(0);
}
$data_element = $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'data')->item(0);
-
+ $sig_element = $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'sig')->item(0);
return array(
- 'data' => trim($data_element->nodeValue),
+ 'data' => preg_replace('/\s/', '', $data_element->nodeValue),
'data_type' => $data_element->getAttribute('type'),
'encoding' => $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'encoding')->item(0)->nodeValue,
'alg' => $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'alg')->item(0)->nodeValue,
- 'sig' => $env_element->getElementsByTagNameNS(MagicEnvelope::NS, 'sig')->item(0)->nodeValue,
+ 'sig' => preg_replace('/\s/', '', $sig_element->nodeValue),
);
}
+}
+/**
+ * Variant of MagicEnvelope using the earlier signature form listed in the MagicEnvelope
+ * spec in early 2010; this was used in StatusNet up through 0.9.6, so for backwards compatiblity
+ * we still need to accept and sometimes send this format.
+ */
+class MagicEnvelopeCompat extends MagicEnvelope {
+
+ /**
+ * StatusNet through 0.9.6 used an earlier version of the MagicEnvelope spec
+ * which used only the input data, without the additional fields, as the plaintext
+ * for signing.
+ *
+ * @param array $env
+ * @return string
+ */
+ public function signingText($env) {
+ return $env['data'];
+ }
}