Merge "Convert article delete to use OOUI"
[lhc/web/wiklou.git] / includes / session / Session.php
index 29878d4..12f16b6 100644 (file)
@@ -46,6 +46,9 @@ use WebRequest;
  * @since 1.27
  */
 final class Session implements \Countable, \Iterator, \ArrayAccess {
+       /** @var null|string[] Encryption algorithm to use */
+       private static $encryptionAlgorithm = null;
+
        /** @var SessionBackend Session backend */
        private $backend;
 
@@ -126,6 +129,11 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
 
        /**
         * Make this session not be persisted across requests
+        *
+        * This will remove persistence information (e.g. delete cookies)
+        * from the associated WebRequest(s), and delete session data in the
+        * backend. The session data will still be available via get() until
+        * the end of the request.
         */
        public function unpersist() {
                $this->backend->unpersist();
@@ -384,7 +392,7 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
         * @return string[] Encryption key, HMAC key
         */
        private function getSecretKeys() {
-               global $wgSessionSecret, $wgSecretKey;
+               global $wgSessionSecret, $wgSecretKey, $wgSessionPbkdf2Iterations;
 
                $wikiSecret = $wgSessionSecret ?: $wgSecretKey;
                $userSecret = $this->get( 'wsSessionSecret', null );
@@ -392,14 +400,70 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
                        $userSecret = \MWCryptRand::generateHex( 32 );
                        $this->set( 'wsSessionSecret', $userSecret );
                }
+               $iterations = $this->get( 'wsSessionPbkdf2Iterations', null );
+               if ( $iterations === null ) {
+                       $iterations = $wgSessionPbkdf2Iterations;
+                       $this->set( 'wsSessionPbkdf2Iterations', $iterations );
+               }
 
-               $keymats = hash_pbkdf2( 'sha256', $wikiSecret, $userSecret, 10001, 64, true );
+               $keymats = hash_pbkdf2( 'sha256', $wikiSecret, $userSecret, $iterations, 64, true );
                return [
                        substr( $keymats, 0, 32 ),
                        substr( $keymats, 32, 32 ),
                ];
        }
 
+       /**
+        * Decide what type of encryption to use, based on system capabilities.
+        * @return array
+        */
+       private static function getEncryptionAlgorithm() {
+               global $wgSessionInsecureSecrets;
+
+               if ( self::$encryptionAlgorithm === null ) {
+                       if ( function_exists( 'openssl_encrypt' ) ) {
+                               $methods = openssl_get_cipher_methods();
+                               if ( in_array( 'aes-256-ctr', $methods, true ) ) {
+                                       self::$encryptionAlgorithm = [ 'openssl', 'aes-256-ctr' ];
+                                       return self::$encryptionAlgorithm;
+                               }
+                               if ( in_array( 'aes-256-cbc', $methods, true ) ) {
+                                       self::$encryptionAlgorithm = [ 'openssl', 'aes-256-cbc' ];
+                                       return self::$encryptionAlgorithm;
+                               }
+                       }
+
+                       if ( function_exists( 'mcrypt_encrypt' )
+                               && in_array( 'rijndael-128', mcrypt_list_algorithms(), true )
+                       ) {
+                               $modes = mcrypt_list_modes();
+                               if ( in_array( 'ctr', $modes, true ) ) {
+                                       self::$encryptionAlgorithm = [ 'mcrypt', 'rijndael-128', 'ctr' ];
+                                       return self::$encryptionAlgorithm;
+                               }
+                               if ( in_array( 'cbc', $modes, true ) ) {
+                                       self::$encryptionAlgorithm = [ 'mcrypt', 'rijndael-128', 'cbc' ];
+                                       return self::$encryptionAlgorithm;
+                               }
+                       }
+
+                       if ( $wgSessionInsecureSecrets ) {
+                               // @todo: import a pure-PHP library for AES instead of this
+                               self::$encryptionAlgorithm = [ 'insecure' ];
+                               return self::$encryptionAlgorithm;
+                       }
+
+                       throw new \BadMethodCallException(
+                               'Encryption is not available. You really should install the PHP OpenSSL extension, ' .
+                               'or failing that the mcrypt extension. But if you really can\'t and you\'re willing ' .
+                               'to accept insecure storage of sensitive session data, set ' .
+                               '$wgSessionInsecureSecrets = true in LocalSettings.php to make this exception go away.'
+                       );
+               }
+
+               return self::$encryptionAlgorithm;
+       }
+
        /**
         * Set a value in the session, encrypted
         *
@@ -409,8 +473,6 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
         * @param mixed $value
         */
        public function setSecret( $key, $value ) {
-               global $wgSessionInsecureSecrets;
-
                list( $encKey, $hmacKey ) = $this->getSecretKeys();
                $serialized = serialize( $value );
 
@@ -420,27 +482,32 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
                // 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.'
-                       );
+               $algorithm = self::getEncryptionAlgorithm();
+               switch ( $algorithm[0] ) {
+                       case 'openssl':
+                               $ciphertext = openssl_encrypt( $serialized, $algorithm[1], $encKey, OPENSSL_RAW_DATA, $iv );
+                               if ( $ciphertext === false ) {
+                                       throw new \UnexpectedValueException( 'Encryption failed: ' . openssl_error_string() );
+                               }
+                               break;
+                       case 'mcrypt':
+                               // PKCS7 padding
+                               $blocksize = mcrypt_get_block_size( $algorithm[1], $algorithm[2] );
+                               $pad = $blocksize - ( strlen( $serialized ) % $blocksize );
+                               $serialized .= str_repeat( chr( $pad ), $pad );
+
+                               $ciphertext = mcrypt_encrypt( $algorithm[1], $encKey, $serialized, $algorithm[2], $iv );
+                               if ( $ciphertext === false ) {
+                                       throw new \UnexpectedValueException( 'Encryption failed' );
+                               }
+                               break;
+                       case 'insecure':
+                               $ex = new \Exception( 'No encryption is available, storing data as plain text' );
+                               $this->logger->warning( $ex->getMessage(), [ 'exception' => $ex ] );
+                               $ciphertext = $serialized;
+                               break;
+                       default:
+                               throw new \LogicException( 'invalid algorithm' );
                }
 
                // Seal
@@ -459,8 +526,6 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
         * @return mixed
         */
        public function getSecret( $key, $default = null ) {
-               global $wgSessionInsecureSecrets;
-
                // Fetch
                $encrypted = $this->get( $key, null );
                if ( $encrypted === null ) {
@@ -488,38 +553,39 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
                }
 
                // 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.'
-                       );
+               $algorithm = self::getEncryptionAlgorithm();
+               switch ( $algorithm[0] ) {
+                       case 'openssl':
+                               $serialized = openssl_decrypt( base64_decode( $ciphertext ), $algorithm[1], $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;
+                               }
+                               break;
+                       case 'mcrypt':
+                               $serialized = mcrypt_decrypt( $algorithm[1], $encKey, base64_decode( $ciphertext ),
+                                       $algorithm[2], base64_decode( $iv ) );
+                               if ( $serialized === false ) {
+                                       $ex = new \Exception( 'Decyption failed' );
+                                       $this->logger->debug( $ex->getMessage(), [ 'exception' => $ex ] );
+                                       return $default;
+                               }
+
+                               // Remove PKCS7 padding
+                               $pad = ord( substr( $serialized, -1 ) );
+                               $serialized = substr( $serialized, 0, -$pad );
+                               break;
+                       case 'insecure':
+                               $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 );
+                               break;
+                       default:
+                               throw new \LogicException( 'invalid algorithm' );
                }
 
                $value = unserialize( $serialized );
@@ -534,7 +600,7 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
         *
         * Calls to save() or clear() will not be delayed.
         *
-        * @return \ScopedCallback When this goes out of scope, a save will be triggered
+        * @return \Wikimedia\ScopedCallback When this goes out of scope, a save will be triggered
         */
        public function delaySave() {
                return $this->backend->delaySave();
@@ -542,6 +608,9 @@ final class Session implements \Countable, \Iterator, \ArrayAccess {
 
        /**
         * Save the session
+        *
+        * This will update the backend data and might re-persist the session
+        * if needed.
         */
        public function save() {
                $this->backend->save();