Wrapper to use OpenPGP with Crypt_RSA

This commit is contained in:
Stephen Paul Weber 2010-04-01 12:53:39 -05:00
parent 6dc7c1eb2a
commit 1e81ed0bb1

138
lib/openpgp_crypt_rsa.php Normal file
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<?php
// This is free and unencumbered software released into the public domain.
/**
* OpenPGP_Crypt_RSA.php is a wrapper for using the classes from OpenPGP.php with Crypt_RSA
*
* @package OpenPGP
* @version 0.0.1
* @author Stephen Paul Weber <singpolyma@singpolyma.net>
* @link http://github.com/singpolyma/openpgp-php
*/
// From http://phpseclib.sourceforge.net/
require 'Crypt/RSA.php';
class OpenPGP_Crypt_RSA {
protected $key, $message;
// Construct a wrapper object from a key or a message packet
function __construct($packet) {
if(!is_object($packet)) $packet = OpenPGP_Message::parse($packet);
if($packet[0] instanceof OpenPGP_PublicKeyPacket) $packet = $packet[0];
if($packet instanceof OpenPGP_PublicKeyPacket) { // If it's a key (other keys are subclasses of this one)
$this->key = $packet;
} else {
$this->message = $packet;
}
}
// Get Crypt_RSA for the public key
function public_key() {
if(!$this->key) return NULL; // No key
return self::convert_public_key($this->key);
}
// Get Crypt_RSA for the private key
function private_key() {
if(!$this->key) return NULL; // No key
return self::convert_private_key($this->key);
}
// Pass a message to verify with this key, or a key (OpenPGP or Crypt_RSA) to check this message with
// Second optional parameter to specify which signature to verify (if there is more than one)
function verify($packet, $index=0) {
if(!is_object($packet)) $packet = OpenPGP_Message::parse($packet);
if($packet[0] instanceof OpenPGP_PublicKeyPacket) $packet = $packet[0];
if($packet instanceof OpenPGP_Message) {
$key = $this->public_key();
list($signature_packet, $data_packet) = $packet->signature_and_data($index);
if(!$key || $signature_packet->key_algorithm_name() != 'RSA') return NULL;
$key->setHash(strtolower($signature_packet->hash_algorithm_name()));
return $packet->verify(array('RSA' => array($signature_packet->hash_algorithm_name() => array($key, 'verify'))));
} else {
list($signature_packet, $data_packet) = $this->message->signature_and_data($index);
if(!$this->message || $signature_packet->key_algorithm_name() != 'RSA') return NULL;
if(!($packet instanceof Crypt_RSA)) $packet = self::convert_public_key($packet);
$packet->setHash(strtolower($signature_packet->hash_algorithm_name()));
return $this->message->verify(array('RSA' => array($signature_packet->hash_algorithm_name() => array($packet, 'verify'))));
}
}
// Pass a message to sign with this key, or a secret key to sign this message with
// Second parameter is hash algorithm to use (default SHA256)
// Third parameter is the 16-digit key ID to use... defaults to the key id in the key packet
function sign($packet, $hash='SHA256', $key_id=NULL) {
if(!is_object($packet)) {
if($this->key) {
$packet = new OpenPGP_LiteralDataPacket($packet);
} else {
$packet = OpenPGP_Message::parse($packet);
$packet = $packet[0];
}
}
if($packet instanceof OpenPGP_SecretKeyPacket || $packet instanceof Crypt_RSA) {
$key = $packet;
$message = $this->message;
} else {
$key = $this->private_key();
$message = $packet;
}
if(!$key || !$message) return NULL; // Missing some data
if($message instanceof OpenPGP_Message) {
list($dummy, $message) = $message->signature_and_data();
}
if(!$key_id) $key_id = substr($key->fingerprint, -16, 16);
if($key instanceof OpenPGP_SecretKeyPacket) $key = self::convert_private_key($key);
$key->setHash(strtolower($hash));
$sig = new OpenPGP_SignaturePacket($message, 'RSA', strtoupper($hash));
$sig->hashed_subpackets[] = new OpenPGP_SignaturePacket_IssuerPacket($key_id);
$sig->sign_data(array('RSA' => array($hash => array($key, 'sign'))));
return new OpenPGP_Message(array($sig, $message));
}
static function crypt_rsa_key($mod, $exp, $hash='SHA256') {
$rsa = new Crypt_RSA();
$rsa->signatureMode = CRYPT_RSA_SIGNATURE_PKCS1;
$rsa->setHash(strtolower($hash));
$rsa->modulus = new Math_BigInteger($mod, 256);
$rsa->k = strlen($rsa->modulus->toBytes());
$rsa->exponent = new Math_BigInteger($exp, 256);
return $rsa;
}
static function convert_key($packet, $private=false) {
if(!is_object($packet)) $packet = OpenPGP_Message::parse($packet);
if($packet instanceof OpenPGP_Message) $packet = $packet[0];
$mod = $packet->key['n'];
$exp = $packet->key['e'];
if($private) $exp = $packet->key['d'];
if(!$exp) return NULL; // Packet doesn't have needed data
$rsa = self::crypt_rsa_key($mod, $exp);
if($private) {
if($packet->key['p'] && $packet->key['q']) $rsa->primes = array($packet->key['p'], $packet->key['q']);
if($packet->key['u']) $rsa->coefficients = array($packet->key['u']);
}
return $rsa;
}
static function convert_public_key($packet) {
return self::convert_key($packet, false);
}
static function convert_private_key($packet) {
return self::convert_key($packet, true);
}
}
?>