diff --git a/lib/openpgp_crypt_aes_tripledes.php b/lib/openpgp_crypt_aes_tripledes.php index 9ba22a4..87145d3 100644 --- a/lib/openpgp_crypt_aes_tripledes.php +++ b/lib/openpgp_crypt_aes_tripledes.php @@ -8,62 +8,46 @@ class OpenPGP_Crypt_AES_TripleDES { public static function decryptSymmetric($pass, $m) { foreach($m as $p) { if($p instanceof OpenPGP_SymmetricSessionKeyPacket) { - switch($p->symmetric_algorithm) { - case 2: - $cipher = new Crypt_TripleDES(CRYPT_DES_MODE_CFB); - $key_bytes = 24; - $key_block_bytes = 8; - break; - case 7: - $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB); - $cipher->setKeyLength(128); - break; - case 8: - $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB); - $cipher->setKeyLength(192); - break; - case 9: - $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB); - $cipher->setKeyLength(256); - break; - } - if(!$cipher) continue; // Unsupported cipher - if(!isset($key_bytes)) $key_bytes = $cipher->key_size; - if(!isset($key_block_bytes)) $key_block_bytes = $cipher->block_size; - + list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($p->symmetric_algorithm); + if(!$cipher) continue; $cipher->setKey($p->s2k->make_key($pass, $key_bytes)); + + if(strlen($p->encrypted_data) > 0) { + $padAmount = $key_block_bytes - (strlen($p->encrypted_data) % $key_block_bytes); + $data = substr($cipher->decrypt($p->encrypted_data . str_repeat("\0", $padAmount)), 0, strlen($p->encrypted_data)); + list($cipher, $key_bytes, $key_block_bytes) = self::getCipher(ord($data{0})); + if(!$cipher) continue; + $cipher->setKey(substr($data, 1)); + } + $epacket = self::getEncryptedData($m); $padAmount = $key_block_bytes - (strlen($epacket->data) % $key_block_bytes); - if(strlen($p->encrypted_data) < 1) { - if($epacket instanceof OpenPGP_IntegrityProtectedDataPacket) { - $data = substr($cipher->decrypt($epacket->data . str_repeat("\0", $padAmount)), 0, strlen($epacket->data)); - $prefix = substr($data, 0, $key_block_bytes + 2); - $mdc = substr(substr($data, -22, 22), 2); - $data = substr($data, $key_block_bytes + 2, -22); + if($epacket instanceof OpenPGP_IntegrityProtectedDataPacket) { + $data = substr($cipher->decrypt($epacket->data . str_repeat("\0", $padAmount)), 0, strlen($epacket->data)); + $prefix = substr($data, 0, $key_block_bytes + 2); + $mdc = substr(substr($data, -22, 22), 2); + $data = substr($data, $key_block_bytes + 2, -22); - $mkMDC = hash("sha1", $prefix . $data . "\xD3\x14", true); - if($mkMDC !== $mdc) return false; + $mkMDC = hash("sha1", $prefix . $data . "\xD3\x14", true); + if($mkMDC !== $mdc) return false; - try { - $msg = OpenPGP_Message::parse($data); - } catch (Exception $ex) { $msg = NULL; } - if($msg) return $msg; /* Otherwise keep trying */ - } else { - // No MDC mean decrypt with resync - $iv = substr($epacket->data, 2, $key_block_bytes); - $edata = substr($epacket->data, $key_block_bytes + 2); - - $cipher->setIV($iv); - $data = substr($cipher->decrypt($edata . str_repeat("\0", $padAmount)), 0, strlen($edata)); - - try { - $msg = OpenPGP_Message::parse($data); - } catch (Exception $ex) { $msg = NULL; } - if($msg) return $msg; /* Otherwise keep trying */ - } + try { + $msg = OpenPGP_Message::parse($data); + } catch (Exception $ex) { $msg = NULL; } + if($msg) return $msg; /* Otherwise keep trying */ } else { - // TODO + // No MDC mean decrypt with resync + $iv = substr($epacket->data, 2, $key_block_bytes); + $edata = substr($epacket->data, $key_block_bytes + 2); + + $cipher->setIV($iv); + $data = substr($cipher->decrypt($edata . str_repeat("\0", $padAmount)), 0, strlen($edata)); + + try { + $msg = OpenPGP_Message::parse($data); + } catch (Exception $ex) { $msg = NULL; } + if($msg) return $msg; /* Otherwise keep trying */ } } } @@ -71,6 +55,34 @@ class OpenPGP_Crypt_AES_TripleDES { return NULL; /* If we get here, we failed */ } + public static function getCipher($algo) { + switch($algo) { + case 2: + $cipher = new Crypt_TripleDES(CRYPT_DES_MODE_CFB); + $key_bytes = 24; + $key_block_bytes = 8; + break; + case 7: + $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB); + $cipher->setKeyLength(128); + break; + case 8: + $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB); + $cipher->setKeyLength(192); + break; + case 9: + $cipher = new Crypt_AES(CRYPT_AES_MODE_CFB); + $cipher->setKeyLength(256); + break; + default: + $cipher = NULL; + } + if(!$cipher) return array(NULL, NULL, NULL); // Unsupported cipher + if(!isset($key_bytes)) $key_bytes = $cipher->key_size; + if(!isset($key_block_bytes)) $key_block_bytes = $cipher->block_size; + return array($cipher, $key_bytes, $key_block_bytes); + } + public static function getEncryptedData($m) { foreach($m as $p) { if($p instanceof OpenPGP_EncryptedDataPacket) return $p; diff --git a/tests/phpseclib_suite.php b/tests/phpseclib_suite.php index c5c0e8d..f9cf725 100644 --- a/tests/phpseclib_suite.php +++ b/tests/phpseclib_suite.php @@ -84,11 +84,9 @@ class Decryption extends PHPUnit_Framework_TestCase { $this->oneSymmetric("hello", "PGP\n", "symmetric-3des.gpg"); } -/* TODO public function testDecryptSessionKey() { $this->oneSymmetric("hello", "PGP\n", "symmetric-with-session-key.gpg"); } -*/ public function testDecryptNoMDC() { $this->oneSymmetric("hello", "PGP\n", "symmetric-no-mdc.gpg");