213 lines
8.0 KiB
PHP
213 lines
8.0 KiB
PHP
<?php
|
|
|
|
use phpseclib\Crypt\AES as Crypt_AES;
|
|
use phpseclib\Crypt\Blowfish as Crypt_Blowfish;
|
|
use phpseclib\Crypt\TripleDES as Crypt_TripleDES;
|
|
use phpseclib\Crypt\Twofish as Crypt_Twofish;
|
|
use phpseclib\Crypt\Random;
|
|
|
|
require_once dirname(__FILE__).'/openpgp.php';
|
|
@include_once dirname(__FILE__).'/openpgp_crypt_rsa.php';
|
|
@include_once dirname(__FILE__).'/openpgp_mcrypt_wrapper.php';
|
|
@include_once dirname(__FILE__).'/openpgp_openssl_wrapper.php';
|
|
|
|
class OpenPGP_Crypt_Symmetric {
|
|
public static function encrypt($passphrases_and_keys, $message, $symmetric_algorithm=9) {
|
|
list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($symmetric_algorithm);
|
|
if(!$cipher) throw new Exception("Unsupported cipher");
|
|
$prefix = Random::string($key_block_bytes);
|
|
$prefix .= substr($prefix, -2);
|
|
|
|
$key = Random::string($key_bytes);
|
|
$cipher->setKey($key);
|
|
|
|
$to_encrypt = $prefix . $message->to_bytes();
|
|
$mdc = new OpenPGP_ModificationDetectionCodePacket(hash('sha1', $to_encrypt . "\xD3\x14", true));
|
|
$to_encrypt .= $mdc->to_bytes();
|
|
$encrypted = array(new OpenPGP_IntegrityProtectedDataPacket($cipher->encrypt($to_encrypt)));
|
|
|
|
if(!is_array($passphrases_and_keys) && !($passphrases_and_keys instanceof IteratorAggregate)) {
|
|
$passphrases_and_keys = (array)$passphrases_and_keys;
|
|
}
|
|
|
|
foreach($passphrases_and_keys as $pass) {
|
|
if($pass instanceof OpenPGP_PublicKeyPacket) {
|
|
if(!in_array($pass->algorithm, array(1,2,3))) throw new Exception("Only RSA keys are supported.");
|
|
$crypt_rsa = new OpenPGP_Crypt_RSA($pass);
|
|
$rsa = $crypt_rsa->public_key();
|
|
$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
|
|
$esk = $rsa->encrypt(chr($symmetric_algorithm) . $key . pack('n', self::checksum($key)));
|
|
$esk = pack('n', OpenPGP::bitlength($esk)) . $esk;
|
|
array_unshift($encrypted, new OpenPGP_AsymmetricSessionKeyPacket($pass->algorithm, $pass->fingerprint(), $esk));
|
|
} else if(is_string($pass)) {
|
|
$s2k = new OpenPGP_S2K(Random::string(10));
|
|
$cipher->setKey($s2k->make_key($pass, $key_bytes));
|
|
$esk = $cipher->encrypt(chr($symmetric_algorithm) . $key);
|
|
array_unshift($encrypted, new OpenPGP_SymmetricSessionKeyPacket($s2k, $esk, $symmetric_algorithm));
|
|
}
|
|
}
|
|
|
|
return new OpenPGP_Message($encrypted);
|
|
}
|
|
|
|
public static function decryptSymmetric($pass, $m) {
|
|
$epacket = self::getEncryptedData($m);
|
|
|
|
foreach($m as $p) {
|
|
if($p instanceof OpenPGP_SymmetricSessionKeyPacket) {
|
|
if(strlen($p->encrypted_data) > 0) {
|
|
list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($p->symmetric_algorithm);
|
|
if(!$cipher) continue;
|
|
$cipher->setKey($p->s2k->make_key($pass, $key_bytes));
|
|
|
|
$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));
|
|
$decrypted = self::decryptPacket($epacket, ord($data{0}), substr($data, 1));
|
|
} else {
|
|
list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($p->symmetric_algorithm);
|
|
$decrypted = self::decryptPacket($epacket, $p->symmetric_algorithm, $p->s2k->make_key($pass, $key_bytes));
|
|
}
|
|
|
|
if($decrypted) return $decrypted;
|
|
}
|
|
}
|
|
|
|
return NULL; /* If we get here, we failed */
|
|
}
|
|
|
|
public static function decryptSecretKey($pass, $packet) {
|
|
$packet = clone $packet; // Do not mutate orinigal
|
|
|
|
list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($packet->symmetric_algorithm);
|
|
if(!$cipher) throw new Exception("Unsupported cipher");
|
|
$cipher->setKey($packet->s2k->make_key($pass, $key_bytes));
|
|
$cipher->setIV(substr($packet->encrypted_data, 0, $key_block_bytes));
|
|
$material = $cipher->decrypt(substr($packet->encrypted_data, $key_block_bytes));
|
|
|
|
if($packet->s2k_useage == 254) {
|
|
$chk = substr($material, -20);
|
|
$material = substr($material, 0, -20);
|
|
if($chk != hash('sha1', $material, true)) return NULL;
|
|
} else {
|
|
$chk = unpack('n', substr($material, -2));
|
|
$chk = reset($chk);
|
|
$material = substr($material, 0, -2);
|
|
|
|
$mkChk = self::checksum($material);
|
|
if($chk != $mkChk) return NULL;
|
|
}
|
|
|
|
$packet->s2k_useage = 0;
|
|
$packet->symmetric_algorithm = 0;
|
|
$packet->encrypted_data = NULL;
|
|
$packet->input = $material;
|
|
$packet->key_from_input();
|
|
unset($packet->input);
|
|
return $packet;
|
|
}
|
|
|
|
public static function decryptPacket($epacket, $symmetric_algorithm, $key) {
|
|
list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($symmetric_algorithm);
|
|
if(!$cipher) return NULL;
|
|
$cipher->setKey($key);
|
|
|
|
if($epacket instanceof OpenPGP_IntegrityProtectedDataPacket) {
|
|
$padAmount = $key_block_bytes - (strlen($epacket->data) % $key_block_bytes);
|
|
$data = substr($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;
|
|
|
|
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);
|
|
$padAmount = $key_block_bytes - (strlen($edata) % $key_block_bytes);
|
|
|
|
$cipher->setIV($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 $msg; /* Otherwise keep trying */
|
|
}
|
|
|
|
return NULL; /* Failed */
|
|
}
|
|
|
|
public static function getCipher($algo) {
|
|
$cipher = NULL;
|
|
switch($algo) {
|
|
case NULL:
|
|
case 0:
|
|
throw new Exception("Data is already unencrypted");
|
|
case 2:
|
|
$cipher = new Crypt_TripleDES(Crypt_TripleDES::MODE_CFB);
|
|
$key_bytes = 24;
|
|
$key_block_bytes = 8;
|
|
break;
|
|
case 3:
|
|
if(class_exists('OpenSSLWrapper')) {
|
|
$cipher = new OpenSSLWrapper("CAST5-CFB");
|
|
} else if(defined('MCRYPT_CAST_128')) {
|
|
$cipher = new MCryptWrapper(MCRYPT_CAST_128);
|
|
} else {
|
|
throw new Exception("Unsupported cipher: you must have mcrypt installed to use CAST5");
|
|
}
|
|
break;
|
|
case 4:
|
|
$cipher = new Crypt_Blowfish(Crypt_Blowfish::MODE_CFB);
|
|
$key_bytes = 16;
|
|
$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;
|
|
case 10:
|
|
$cipher = new Crypt_Twofish(Crypt_Twofish::MODE_CFB);
|
|
if(method_exists($cipher, 'setKeyLength')) {
|
|
$cipher->setKeyLength(256);
|
|
} else {
|
|
$cipher = NULL;
|
|
}
|
|
break;
|
|
}
|
|
if(!$cipher) return array(NULL, NULL, NULL); // Unsupported cipher
|
|
if(!isset($key_bytes)) $key_bytes = isset($cipher->key_size)?$cipher->key_size:$cipher->key_length;
|
|
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 $p;
|
|
}
|
|
throw new Exception("Can only decrypt EncryptedDataPacket");
|
|
}
|
|
|
|
public static function checksum($s) {
|
|
$mkChk = 0;
|
|
for($i = 0; $i < strlen($s); $i++) {
|
|
$mkChk = ($mkChk + ord($s{$i})) % 65536;
|
|
}
|
|
return $mkChk;
|
|
}
|
|
}
|