$this->remove( 'wsTokenSecrets' );
}
+ /**
+ * Fetch the secret keys for self::setSecret() and self::getSecret().
+ * @return string[] Encryption key, HMAC key
+ */
+ private function getSecretKeys() {
+ global $wgSessionSecret, $wgSecretKey;
+
+ $wikiSecret = $wgSessionSecret ?: $wgSecretKey;
+ $userSecret = $this->get( 'wsSessionSecret', null );
+ if ( $userSecret === null ) {
+ $userSecret = \MWCryptRand::generateHex( 32 );
+ $this->set( 'wsSessionSecret', $userSecret );
+ }
+
+ $keymats = hash_pbkdf2( 'sha256', $wikiSecret, $userSecret, 10001, 64, true );
+ return [
+ substr( $keymats, 0, 32 ),
+ substr( $keymats, 32, 32 ),
+ ];
+ }
+
+ /**
+ * Set a value in the session, encrypted
+ *
+ * This relies on the secrecy of $wgSecretKey (by default), or $wgSessionSecret.
+ *
+ * @param string|int $key
+ * @param mixed $value
+ */
+ public function setSecret( $key, $value ) {
+ global $wgSessionInsecureSecrets;
+
+ list( $encKey, $hmacKey ) = $this->getSecretKeys();
+ $serialized = serialize( $value );
+
+ // The code for encryption (with OpenSSL) and sealing is taken from
+ // Chris Steipp's OATHAuthUtils class in Extension::OATHAuth.
+
+ // Encrypt
+ // @todo: import a pure-PHP library for AES instead of doing $wgSessionInsecureSecrets
+ $iv = \MWCryptRand::generate( 16, true );
+ if ( function_exists( 'openssl_encrypt' ) ) {
+ $ciphertext = openssl_encrypt( $serialized, 'aes-256-ctr', $encKey, OPENSSL_RAW_DATA, $iv );
+ if ( $ciphertext === false ) {
+ throw new UnexpectedValueException( 'Encryption failed: ' . openssl_error_string() );
+ }
+ } elseif ( function_exists( 'mcrypt_encrypt' ) ) {
+ $ciphertext = mcrypt_encrypt( 'rijndael-128', $encKey, $serialized, 'ctr', $iv );
+ if ( $ciphertext === false ) {
+ throw new UnexpectedValueException( 'Encryption failed' );
+ }
+ } elseif ( $wgSessionInsecureSecrets ) {
+ $ex = new \Exception( 'No encryption is available, storing data as plain text' );
+ $this->logger->warning( $ex->getMessage(), [ 'exception' => $ex ] );
+ $ciphertext = $serialized;
+ } else {
+ throw new \BadMethodCallException(
+ 'Encryption is not available. You really should install the PHP OpenSSL extension, ' .
+ 'or failing that the mcrypt extension. But if you really can\'t and you\'re willing ' .
+ 'to accept insecure storage of sensitive session data, set ' .
+ '$wgSessionInsecureSecrets = true in LocalSettings.php to make this exception go away.'
+ );
+ }
+
+ // Seal
+ $sealed = base64_encode( $iv ) . '.' . base64_encode( $ciphertext );
+ $hmac = hash_hmac( 'sha256', $sealed, $hmacKey, true );
+ $encrypted = base64_encode( $hmac ) . '.' . $sealed;
+
+ // Store
+ $this->set( $key, $encrypted );
+ }
+
+ /**
+ * Fetch a value from the session that was set with self::setSecret()
+ * @param string|int $key
+ * @param mixed $default Returned if $this->exists( $key ) would be false or decryption fails
+ * @return mixed
+ */
+ public function getSecret( $key, $default = null ) {
+ global $wgSessionInsecureSecrets;
+
+ // Fetch
+ $encrypted = $this->get( $key, null );
+ if ( $encrypted === null ) {
+ return $default;
+ }
+
+ // The code for unsealing, checking, and decrypting (with OpenSSL) is
+ // taken from Chris Steipp's OATHAuthUtils class in
+ // Extension::OATHAuth.
+
+ // Unseal and check
+ $pieces = explode( '.', $encrypted );
+ if ( count( $pieces ) !== 3 ) {
+ $ex = new \Exception( 'Invalid sealed-secret format' );
+ $this->logger->warning( $ex->getMessage(), [ 'exception' => $ex ] );
+ return $default;
+ }
+ list( $hmac, $iv, $ciphertext ) = $pieces;
+ list( $encKey, $hmacKey ) = $this->getSecretKeys();
+ $integCalc = hash_hmac( 'sha256', $iv . '.' . $ciphertext, $hmacKey, true );
+ if ( !hash_equals( $integCalc, base64_decode( $hmac ) ) ) {
+ $ex = new \Exception( 'Sealed secret has been tampered with, aborting.' );
+ $this->logger->warning( $ex->getMessage(), [ 'exception' => $ex ] );
+ return $default;
+ }
+
+ // Decrypt
+ // @todo: import a pure-PHP library for AES instead of doing $wgSessionInsecureSecrets
+ if ( function_exists( 'openssl_decrypt' ) ) {
+ $serialized = openssl_decrypt(
+ base64_decode( $ciphertext ), 'aes-256-ctr', $encKey, OPENSSL_RAW_DATA, base64_decode( $iv )
+ );
+ if ( $serialized === false ) {
+ $ex = new \Exception( 'Decyption failed: ' . openssl_error_string() );
+ $this->logger->debug( $ex->getMessage(), [ 'exception' => $ex ] );
+ return $default;
+ }
+ } elseif ( function_exists( 'mcrypt_decrypt' ) ) {
+ $serialized = mcrypt_decrypt(
+ 'rijndael-128', $encKey, base64_decode( $ciphertext ), 'ctr', base64_decode( $iv )
+ );
+ if ( $serialized === false ) {
+ $ex = new \Exception( 'Decyption failed' );
+ $this->logger->debug( $ex->getMessage(), [ 'exception' => $ex ] );
+ return $default;
+ }
+ } elseif ( $wgSessionInsecureSecrets ) {
+ $ex = new \Exception(
+ 'No encryption is available, retrieving data that was stored as plain text'
+ );
+ $this->logger->warning( $ex->getMessage(), [ 'exception' => $ex ] );
+ $serialized = base64_decode( $ciphertext );
+ } else {
+ throw new \BadMethodCallException(
+ 'Encryption is not available. You really should install the PHP OpenSSL extension, ' .
+ 'or failing that the mcrypt extension. But if you really can\'t and you\'re willing ' .
+ 'to accept insecure storage of sensitive session data, set ' .
+ '$wgSessionInsecureSecrets = true in LocalSettings.php to make this exception go away.'
+ );
+ }
+
+ $value = unserialize( $serialized );
+ if ( $value === false && $serialized !== serialize( false ) ) {
+ $value = $default;
+ }
+ return $value;
+ }
+
/**
* Delay automatic saving while multiple updates are being made
*
dépôts / lhc / web / wiklou.git / blobdiff