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tgseclib/phpseclib/Crypt/RSA.php
terrafrost 2f8d1055ea Use OpenSSL for Math_BigInteger::modPow speedups 
Also, make Crypt_RSA's public keys compatible with OpenSSL and make it so __toString will return the key even when it's the public key that's loaded and it hasn't been set as the public key.
2012-08-26 01:36:34 -05:00

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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Pure-PHP PKCS#1 (v2.1) compliant implementation of RSA.
*
* PHP versions 4 and 5
*
* Here's an example of how to encrypt and decrypt text with this library:
* <code>
* <?php
* include('Crypt/RSA.php');
*
* $rsa = new Crypt_RSA();
* extract($rsa->createKey());
*
* $plaintext = 'terrafrost';
*
* $rsa->loadKey($privatekey);
* $ciphertext = $rsa->encrypt($plaintext);
*
* $rsa->loadKey($publickey);
* echo $rsa->decrypt($ciphertext);
* ?>
* </code>
*
* Here's an example of how to create signatures and verify signatures with this library:
* <code>
* <?php
* include('Crypt/RSA.php');
*
* $rsa = new Crypt_RSA();
* extract($rsa->createKey());
*
* $plaintext = 'terrafrost';
*
* $rsa->loadKey($privatekey);
* $signature = $rsa->sign($plaintext);
*
* $rsa->loadKey($publickey);
* echo $rsa->verify($plaintext, $signature) ? 'verified' : 'unverified';
* ?>
* </code>
*
* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @category Crypt
* @package Crypt_RSA
* @author Jim Wigginton <terrafrost@php.net>
* @copyright MMIX Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @version $Id: RSA.php,v 1.19 2010/09/12 21:58:54 terrafrost Exp $
* @link http://phpseclib.sourceforge.net
*/
/**
* Include Math_BigInteger
*/
if (!class_exists('Math_BigInteger')) {
require_once('Math/BigInteger.php');
}
/**
* Include Crypt_Random
*/
// the class_exists() will only be called if the crypt_random function hasn't been defined and
// will trigger a call to __autoload() if you're wanting to auto-load classes
// call function_exists() a second time to stop the require_once from being called outside
// of the auto loader
if (!function_exists('crypt_random') && !class_exists('Crypt_Random') && !function_exists('crypt_random')) {
require_once('Crypt/Random.php');
}
/**
* Include Crypt_Hash
*/
if (!class_exists('Crypt_Hash')) {
require_once('Crypt/Hash.php');
}
/**#@+
* @access public
* @see Crypt_RSA::encrypt()
* @see Crypt_RSA::decrypt()
*/
/**
* Use {@link http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding Optimal Asymmetric Encryption Padding}
* (OAEP) for encryption / decryption.
*
* Uses sha1 by default.
*
* @see Crypt_RSA::setHash()
* @see Crypt_RSA::setMGFHash()
*/
define('CRYPT_RSA_ENCRYPTION_OAEP', 1);
/**
* Use PKCS#1 padding.
*
* Although CRYPT_RSA_ENCRYPTION_OAEP offers more security, including PKCS#1 padding is necessary for purposes of backwards
* compatability with protocols (like SSH-1) written before OAEP's introduction.
*/
define('CRYPT_RSA_ENCRYPTION_PKCS1', 2);
/**#@-*/
/**#@+
* @access public
* @see Crypt_RSA::sign()
* @see Crypt_RSA::verify()
* @see Crypt_RSA::setHash()
*/
/**
* Use the Probabilistic Signature Scheme for signing
*
* Uses sha1 by default.
*
* @see Crypt_RSA::setSaltLength()
* @see Crypt_RSA::setMGFHash()
*/
define('CRYPT_RSA_SIGNATURE_PSS', 1);
/**
* Use the PKCS#1 scheme by default.
*
* Although CRYPT_RSA_SIGNATURE_PSS offers more security, including PKCS#1 signing is necessary for purposes of backwards
* compatability with protocols (like SSH-2) written before PSS's introduction.
*/
define('CRYPT_RSA_SIGNATURE_PKCS1', 2);
/**#@-*/
/**#@+
* @access private
* @see Crypt_RSA::createKey()
*/
/**
* ASN1 Integer
*/
define('CRYPT_RSA_ASN1_INTEGER', 2);
/**
* ASN1 Bit String
*/
define('CRYPT_RSA_ASN1_BITSTRING', 3);
/**
* ASN1 Sequence (with the constucted bit set)
*/
define('CRYPT_RSA_ASN1_SEQUENCE', 48);
/**#@-*/
/**#@+
* @access private
* @see Crypt_RSA::Crypt_RSA()
*/
/**
* To use the pure-PHP implementation
*/
define('CRYPT_RSA_MODE_INTERNAL', 1);
/**
* To use the OpenSSL library
*
* (if enabled; otherwise, the internal implementation will be used)
*/
define('CRYPT_RSA_MODE_OPENSSL', 2);
/**#@-*/
/**#@+
* @access public
* @see Crypt_RSA::createKey()
* @see Crypt_RSA::setPrivateKeyFormat()
*/
/**
* PKCS#1 formatted private key
*
* Used by OpenSSH
*/
define('CRYPT_RSA_PRIVATE_FORMAT_PKCS1', 0);
/**
* PuTTY formatted private key
*/
define('CRYPT_RSA_PRIVATE_FORMAT_PUTTY', 1);
/**
* XML formatted private key
*/
define('CRYPT_RSA_PRIVATE_FORMAT_XML', 2);
/**#@-*/
/**#@+
* @access public
* @see Crypt_RSA::createKey()
* @see Crypt_RSA::setPublicKeyFormat()
*/
/**
* Raw public key
*
* An array containing two Math_BigInteger objects.
*
* The exponent can be indexed with any of the following:
*
* 0, e, exponent, publicExponent
*
* The modulus can be indexed with any of the following:
*
* 1, n, modulo, modulus
*/
define('CRYPT_RSA_PUBLIC_FORMAT_RAW', 3);
/**
* PKCS#1 formatted public key
*/
define('CRYPT_RSA_PUBLIC_FORMAT_PKCS1', 4);
/**
* XML formatted public key
*/
define('CRYPT_RSA_PUBLIC_FORMAT_XML', 5);
/**
* OpenSSH formatted public key
*
* Place in $HOME/.ssh/authorized_keys
*/
define('CRYPT_RSA_PUBLIC_FORMAT_OPENSSH', 6);
/**#@-*/
/**
* Pure-PHP PKCS#1 compliant implementation of RSA.
*
* @author Jim Wigginton <terrafrost@php.net>
* @version 0.1.0
* @access public
* @package Crypt_RSA
*/
class Crypt_RSA {
/**
* Precomputed Zero
*
* @var Array
* @access private
*/
var $zero;
/**
* Precomputed One
*
* @var Array
* @access private
*/
var $one;
/**
* Private Key Format
*
* @var Integer
* @access private
*/
var $privateKeyFormat = CRYPT_RSA_PRIVATE_FORMAT_PKCS1;
/**
* Public Key Format
*
* @var Integer
* @access public
*/
var $publicKeyFormat = CRYPT_RSA_PUBLIC_FORMAT_PKCS1;
/**
* Modulus (ie. n)
*
* @var Math_BigInteger
* @access private
*/
var $modulus;
/**
* Modulus length
*
* @var Math_BigInteger
* @access private
*/
var $k;
/**
* Exponent (ie. e or d)
*
* @var Math_BigInteger
* @access private
*/
var $exponent;
/**
* Primes for Chinese Remainder Theorem (ie. p and q)
*
* @var Array
* @access private
*/
var $primes;
/**
* Exponents for Chinese Remainder Theorem (ie. dP and dQ)
*
* @var Array
* @access private
*/
var $exponents;
/**
* Coefficients for Chinese Remainder Theorem (ie. qInv)
*
* @var Array
* @access private
*/
var $coefficients;
/**
* Hash name
*
* @var String
* @access private
*/
var $hashName;
/**
* Hash function
*
* @var Crypt_Hash
* @access private
*/
var $hash;
/**
* Length of hash function output
*
* @var Integer
* @access private
*/
var $hLen;
/**
* Length of salt
*
* @var Integer
* @access private
*/
var $sLen;
/**
* Hash function for the Mask Generation Function
*
* @var Crypt_Hash
* @access private
*/
var $mgfHash;
/**
* Length of MGF hash function output
*
* @var Integer
* @access private
*/
var $mgfHLen;
/**
* Encryption mode
*
* @var Integer
* @access private
*/
var $encryptionMode = CRYPT_RSA_ENCRYPTION_OAEP;
/**
* Signature mode
*
* @var Integer
* @access private
*/
var $signatureMode = CRYPT_RSA_SIGNATURE_PSS;
/**
* Public Exponent
*
* @var Mixed
* @access private
*/
var $publicExponent = false;
/**
* Password
*
* @var String
* @access private
*/
var $password = false;
/**
* Components
*
* For use with parsing XML formatted keys. PHP's XML Parser functions use utilized - instead of PHP's DOM functions -
* because PHP's XML Parser functions work on PHP4 whereas PHP's DOM functions - although surperior - don't.
*
* @see Crypt_RSA::_start_element_handler()
* @var Array
* @access private
*/
var $components = array();
/**
* Current String
*
* For use with parsing XML formatted keys.
*
* @see Crypt_RSA::_character_handler()
* @see Crypt_RSA::_stop_element_handler()
* @var Mixed
* @access private
*/
var $current;
/**
* The constructor
*
* If you want to make use of the openssl extension, you'll need to set the mode manually, yourself. The reason
* Crypt_RSA doesn't do it is because OpenSSL doesn't fail gracefully. openssl_pkey_new(), in particular, requires
* openssl.cnf be present somewhere and, unfortunately, the only real way to find out is too late.
*
* @return Crypt_RSA
* @access public
*/
function Crypt_RSA()
{
if ( !defined('CRYPT_RSA_MODE') ) {
switch (true) {
case extension_loaded('openssl') && version_compare(PHP_VERSION, '4.2.0', '>='):
define('CRYPT_RSA_MODE', CRYPT_RSA_MODE_OPENSSL);
break;
default:
define('CRYPT_RSA_MODE', CRYPT_RSA_MODE_INTERNAL);
}
}
if (!defined('CRYPT_RSA_COMMENT')) {
define('CRYPT_RSA_COMMENT', 'phpseclib-generated-key');
}
$this->zero = new Math_BigInteger();
$this->one = new Math_BigInteger(1);
$this->hash = new Crypt_Hash('sha1');
$this->hLen = $this->hash->getLength();
$this->hashName = 'sha1';
$this->mgfHash = new Crypt_Hash('sha1');
$this->mgfHLen = $this->mgfHash->getLength();
}
/**
* Create public / private key pair
*
* Returns an array with the following three elements:
* - 'privatekey': The private key.
* - 'publickey': The public key.
* - 'partialkey': A partially computed key (if the execution time exceeded $timeout).
* Will need to be passed back to Crypt_RSA::createKey() as the third parameter for further processing.
*
* @access public
* @param optional Integer $bits
* @param optional Integer $timeout
* @param optional Math_BigInteger $p
*/
function createKey($bits = 1024, $timeout = false, $partial = array())
{
if (!defined('CRYPT_RSA_EXPONENT')) {
// http://en.wikipedia.org/wiki/65537_%28number%29
define('CRYPT_RSA_EXPONENT', '65537');
}
// per <http://cseweb.ucsd.edu/~hovav/dist/survey.pdf#page=5>, this number ought not result in primes smaller
// than 256 bits. as a consequence if the key you're trying to create is 1024 bits and you've set CRYPT_RSA_SMALLEST_PRIME
// to 384 bits then you're going to get a 384 bit prime and a 640 bit prime (384 + 1024 % 384). at least if
// CRYPT_RSA_MODE is set to CRYPT_RSA_MODE_INTERNAL. if CRYPT_RSA_MODE is set to CRYPT_RSA_MODE_OPENSSL then
// CRYPT_RSA_SMALLEST_PRIME is ignored (ie. multi-prime RSA support is more intended as a way to speed up RSA key
// generation when there's a chance neither gmp nor OpenSSL are installed)
if (!defined('CRYPT_RSA_SMALLEST_PRIME')) {
define('CRYPT_RSA_SMALLEST_PRIME', 4096);
}
// OpenSSL uses 65537 as the exponent and requires RSA keys be 384 bits minimum
if ( CRYPT_RSA_MODE == CRYPT_RSA_MODE_OPENSSL && $bits >= 384 && CRYPT_RSA_EXPONENT == 65537) {
$rsa = openssl_pkey_new(array(
'private_key_bits' => $bits,
'config' => dirname(__FILE__) . '/../openssl.cnf'
));
openssl_pkey_export($rsa, $privatekey, NULL, array('config' => dirname(__FILE__) . '/../openssl.cnf'));
$publickey = openssl_pkey_get_details($rsa);
$publickey = $publickey['key'];
if ($this->privateKeyFormat != CRYPT_RSA_PRIVATE_FORMAT_PKCS1) {
$privatekey = call_user_func_array(array($this, '_convertPrivateKey'), array_values($this->_parseKey($privatekey, CRYPT_RSA_PRIVATE_FORMAT_PKCS1)));
$publickey = call_user_func_array(array($this, '_convertPublicKey'), array_values($this->_parseKey($publickey, CRYPT_RSA_PUBLIC_FORMAT_PKCS1)));
}
// clear the buffer of error strings stemming from a minimalistic openssl.cnf
while (openssl_error_string() !== false);
return array(
'privatekey' => $privatekey,
'publickey' => $publickey,
'partialkey' => false
);
}
static $e;
if (!isset($e)) {
$e = new Math_BigInteger(CRYPT_RSA_EXPONENT);
}
extract($this->_generateMinMax($bits));
$absoluteMin = $min;
$temp = $bits >> 1; // divide by two to see how many bits P and Q would be
if ($temp > CRYPT_RSA_SMALLEST_PRIME) {
$num_primes = floor($bits / CRYPT_RSA_SMALLEST_PRIME);
$temp = CRYPT_RSA_SMALLEST_PRIME;
} else {
$num_primes = 2;
}
extract($this->_generateMinMax($temp + $bits % $temp));
$finalMax = $max;
extract($this->_generateMinMax($temp));
$generator = new Math_BigInteger();
$generator->setRandomGenerator('crypt_random');
$n = $this->one->copy();
if (!empty($partial)) {
extract(unserialize($partial));
} else {
$exponents = $coefficients = $primes = array();
$lcm = array(
'top' => $this->one->copy(),
'bottom' => false
);
}
$start = time();
$i0 = count($primes) + 1;
do {
for ($i = $i0; $i <= $num_primes; $i++) {
if ($timeout !== false) {
$timeout-= time() - $start;
$start = time();
if ($timeout <= 0) {
return array(
'privatekey' => '',
'publickey' => '',
'partialkey' => serialize(array(
'primes' => $primes,
'coefficients' => $coefficients,
'lcm' => $lcm,
'exponents' => $exponents
))
);
}
}
if ($i == $num_primes) {
list($min, $temp) = $absoluteMin->divide($n);
if (!$temp->equals($this->zero)) {
$min = $min->add($this->one); // ie. ceil()
}
$primes[$i] = $generator->randomPrime($min, $finalMax, $timeout);
} else {
$primes[$i] = $generator->randomPrime($min, $max, $timeout);
}
if ($primes[$i] === false) { // if we've reached the timeout
if (count($primes) > 1) {
$partialkey = '';
} else {
array_pop($primes);
$partialkey = serialize(array(
'primes' => $primes,
'coefficients' => $coefficients,
'lcm' => $lcm,
'exponents' => $exponents
));
}
return array(
'privatekey' => '',
'publickey' => '',
'partialkey' => $partialkey
);
}
// the first coefficient is calculated differently from the rest
// ie. instead of being $primes[1]->modInverse($primes[2]), it's $primes[2]->modInverse($primes[1])
if ($i > 2) {
$coefficients[$i] = $n->modInverse($primes[$i]);
}
$n = $n->multiply($primes[$i]);
$temp = $primes[$i]->subtract($this->one);
// textbook RSA implementations use Euler's totient function instead of the least common multiple.
// see http://en.wikipedia.org/wiki/Euler%27s_totient_function
$lcm['top'] = $lcm['top']->multiply($temp);
$lcm['bottom'] = $lcm['bottom'] === false ? $temp : $lcm['bottom']->gcd($temp);
$exponents[$i] = $e->modInverse($temp);
}
list($lcm) = $lcm['top']->divide($lcm['bottom']);
$gcd = $lcm->gcd($e);
$i0 = 1;
} while (!$gcd->equals($this->one));
$d = $e->modInverse($lcm);
$coefficients[2] = $primes[2]->modInverse($primes[1]);
// from <http://tools.ietf.org/html/rfc3447#appendix-A.1.2>:
// RSAPrivateKey ::= SEQUENCE {
// version Version,
// modulus INTEGER, -- n
// publicExponent INTEGER, -- e
// privateExponent INTEGER, -- d
// prime1 INTEGER, -- p
// prime2 INTEGER, -- q
// exponent1 INTEGER, -- d mod (p-1)
// exponent2 INTEGER, -- d mod (q-1)
// coefficient INTEGER, -- (inverse of q) mod p
// otherPrimeInfos OtherPrimeInfos OPTIONAL
// }
return array(
'privatekey' => $this->_convertPrivateKey($n, $e, $d, $primes, $exponents, $coefficients),
'publickey' => $this->_convertPublicKey($n, $e),
'partialkey' => false
);
}
/**
* Convert a private key to the appropriate format.
*
* @access private
* @see setPrivateKeyFormat()
* @param String $RSAPrivateKey
* @return String
*/
function _convertPrivateKey($n, $e, $d, $primes, $exponents, $coefficients)
{
$num_primes = count($primes);
$raw = array(
'version' => $num_primes == 2 ? chr(0) : chr(1), // two-prime vs. multi
'modulus' => $n->toBytes(true),
'publicExponent' => $e->toBytes(true),
'privateExponent' => $d->toBytes(true),
'prime1' => $primes[1]->toBytes(true),
'prime2' => $primes[2]->toBytes(true),
'exponent1' => $exponents[1]->toBytes(true),
'exponent2' => $exponents[2]->toBytes(true),
'coefficient' => $coefficients[2]->toBytes(true)
);
// if the format in question does not support multi-prime rsa and multi-prime rsa was used,
// call _convertPublicKey() instead.
switch ($this->privateKeyFormat) {
case CRYPT_RSA_PRIVATE_FORMAT_XML:
if ($num_primes != 2) {
return false;
}
return "<RSAKeyValue>\r\n" .
' <Modulus>' . base64_encode($raw['modulus']) . "</Modulus>\r\n" .
' <Exponent>' . base64_encode($raw['publicExponent']) . "</Exponent>\r\n" .
' <P>' . base64_encode($raw['prime1']) . "</P>\r\n" .
' <Q>' . base64_encode($raw['prime2']) . "</Q>\r\n" .
' <DP>' . base64_encode($raw['exponent1']) . "</DP>\r\n" .
' <DQ>' . base64_encode($raw['exponent2']) . "</DQ>\r\n" .
' <InverseQ>' . base64_encode($raw['coefficient']) . "</InverseQ>\r\n" .
' <D>' . base64_encode($raw['privateExponent']) . "</D>\r\n" .
'</RSAKeyValue>';
break;
case CRYPT_RSA_PRIVATE_FORMAT_PUTTY:
if ($num_primes != 2) {
return false;
}
$key = "PuTTY-User-Key-File-2: ssh-rsa\r\nEncryption: ";
$encryption = (!empty($this->password) || is_string($this->password)) ? 'aes256-cbc' : 'none';
$key.= $encryption;
$key.= "\r\nComment: " . CRYPT_RSA_COMMENT . "\r\n";
$public = pack('Na*Na*Na*',
strlen('ssh-rsa'), 'ssh-rsa', strlen($raw['publicExponent']), $raw['publicExponent'], strlen($raw['modulus']), $raw['modulus']
);
$source = pack('Na*Na*Na*Na*',
strlen('ssh-rsa'), 'ssh-rsa', strlen($encryption), $encryption,
strlen(CRYPT_RSA_COMMENT), CRYPT_RSA_COMMENT, strlen($public), $public
);
$public = base64_encode($public);
$key.= "Public-Lines: " . ((strlen($public) + 32) >> 6) . "\r\n";
$key.= chunk_split($public, 64);
$private = pack('Na*Na*Na*Na*',
strlen($raw['privateExponent']), $raw['privateExponent'], strlen($raw['prime1']), $raw['prime1'],
strlen($raw['prime2']), $raw['prime2'], strlen($raw['coefficient']), $raw['coefficient']
);
if (empty($this->password) && !is_string($this->password)) {
$source.= pack('Na*', strlen($private), $private);
$hashkey = 'putty-private-key-file-mac-key';
} else {
$private.= $this->_random(16 - (strlen($private) & 15));
$source.= pack('Na*', strlen($private), $private);
if (!class_exists('Crypt_AES')) {
require_once('Crypt/AES.php');
}
$sequence = 0;
$symkey = '';
while (strlen($symkey) < 32) {
$temp = pack('Na*', $sequence++, $this->password);
$symkey.= pack('H*', sha1($temp));
}
$symkey = substr($symkey, 0, 32);
$crypto = new Crypt_AES();
$crypto->setKey($symkey);
$crypto->disablePadding();
$private = $crypto->encrypt($private);
$hashkey = 'putty-private-key-file-mac-key' . $this->password;
}
$private = base64_encode($private);
$key.= 'Private-Lines: ' . ((strlen($private) + 32) >> 6) . "\r\n";
$key.= chunk_split($private, 64);
if (!class_exists('Crypt_Hash')) {
require_once('Crypt/Hash.php');
}
$hash = new Crypt_Hash('sha1');
$hash->setKey(pack('H*', sha1($hashkey)));
$key.= 'Private-MAC: ' . bin2hex($hash->hash($source)) . "\r\n";
return $key;
default: // eg. CRYPT_RSA_PRIVATE_FORMAT_PKCS1
$components = array();
foreach ($raw as $name => $value) {
$components[$name] = pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($value)), $value);
}
$RSAPrivateKey = implode('', $components);
if ($num_primes > 2) {
$OtherPrimeInfos = '';
for ($i = 3; $i <= $num_primes; $i++) {
// OtherPrimeInfos ::= SEQUENCE SIZE(1..MAX) OF OtherPrimeInfo
//
// OtherPrimeInfo ::= SEQUENCE {
// prime INTEGER, -- ri
// exponent INTEGER, -- di
// coefficient INTEGER -- ti
// }
$OtherPrimeInfo = pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($primes[$i]->toBytes(true))), $primes[$i]->toBytes(true));
$OtherPrimeInfo.= pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($exponents[$i]->toBytes(true))), $exponents[$i]->toBytes(true));
$OtherPrimeInfo.= pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($coefficients[$i]->toBytes(true))), $coefficients[$i]->toBytes(true));
$OtherPrimeInfos.= pack('Ca*a*', CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($OtherPrimeInfo)), $OtherPrimeInfo);
}
$RSAPrivateKey.= pack('Ca*a*', CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($OtherPrimeInfos)), $OtherPrimeInfos);
}
$RSAPrivateKey = pack('Ca*a*', CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($RSAPrivateKey)), $RSAPrivateKey);
if (!empty($this->password) || is_string($this->password)) {
$iv = $this->_random(8);
$symkey = pack('H*', md5($this->password . $iv)); // symkey is short for symmetric key
$symkey.= substr(pack('H*', md5($symkey . $this->password . $iv)), 0, 8);
if (!class_exists('Crypt_TripleDES')) {
require_once('Crypt/TripleDES.php');
}
$des = new Crypt_TripleDES();
$des->setKey($symkey);
$des->setIV($iv);
$iv = strtoupper(bin2hex($iv));
$RSAPrivateKey = "-----BEGIN RSA PRIVATE KEY-----\r\n" .
"Proc-Type: 4,ENCRYPTED\r\n" .
"DEK-Info: DES-EDE3-CBC,$iv\r\n" .
"\r\n" .
chunk_split(base64_encode($des->encrypt($RSAPrivateKey))) .
'-----END RSA PRIVATE KEY-----';
} else {
$RSAPrivateKey = "-----BEGIN RSA PRIVATE KEY-----\r\n" .
chunk_split(base64_encode($RSAPrivateKey)) .
'-----END RSA PRIVATE KEY-----';
}
return $RSAPrivateKey;
}
}
/**
* Convert a public key to the appropriate format
*
* @access private
* @see setPublicKeyFormat()
* @param String $RSAPrivateKey
* @return String
*/
function _convertPublicKey($n, $e)
{
$modulus = $n->toBytes(true);
$publicExponent = $e->toBytes(true);
switch ($this->publicKeyFormat) {
case CRYPT_RSA_PUBLIC_FORMAT_RAW:
return array('e' => $e->copy(), 'n' => $n->copy());
case CRYPT_RSA_PUBLIC_FORMAT_XML:
return "<RSAKeyValue>\r\n" .
' <Modulus>' . base64_encode($modulus) . "</Modulus>\r\n" .
' <Exponent>' . base64_encode($publicExponent) . "</Exponent>\r\n" .
'</RSAKeyValue>';
break;
case CRYPT_RSA_PUBLIC_FORMAT_OPENSSH:
// from <http://tools.ietf.org/html/rfc4253#page-15>:
// string "ssh-rsa"
// mpint e
// mpint n
$RSAPublicKey = pack('Na*Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($publicExponent), $publicExponent, strlen($modulus), $modulus);
$RSAPublicKey = 'ssh-rsa ' . base64_encode($RSAPublicKey) . ' ' . CRYPT_RSA_COMMENT;
return $RSAPublicKey;
default: // eg. CRYPT_RSA_PUBLIC_FORMAT_PKCS1
// from <http://tools.ietf.org/html/rfc3447#appendix-A.1.1>:
// RSAPublicKey ::= SEQUENCE {
// modulus INTEGER, -- n
// publicExponent INTEGER -- e
// }
$components = array(
'modulus' => pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($modulus)), $modulus),
'publicExponent' => pack('Ca*a*', CRYPT_RSA_ASN1_INTEGER, $this->_encodeLength(strlen($publicExponent)), $publicExponent)
);
$RSAPublicKey = pack('Ca*a*a*',
CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($components['modulus']) + strlen($components['publicExponent'])),
$components['modulus'], $components['publicExponent']
);
$rsaOID = pack('H*', '300d06092a864886f70d0101010500'); // hex version of MA0GCSqGSIb3DQEBAQUA
$RSAPublicKey = chr(0) . $RSAPublicKey;
$RSAPublicKey = chr(3) . $this->_encodeLength(strlen($RSAPublicKey)) . $RSAPublicKey;
$encapsulated = pack('Ca*a*',
CRYPT_RSA_ASN1_SEQUENCE, $this->_encodeLength(strlen($rsaOID . $RSAPublicKey)), $rsaOID . $RSAPublicKey
);
$RSAPublicKey = "-----BEGIN PUBLIC KEY-----\r\n" .
chunk_split(base64_encode($encapsulated)) .
'-----END PUBLIC KEY-----';
return $RSAPublicKey;
}
}
/**
* Break a public or private key down into its constituant components
*
* @access private
* @see _convertPublicKey()
* @see _convertPrivateKey()
* @param String $key
* @param Integer $type
* @return Array
*/
function _parseKey($key, $type)
{
if ($type != CRYPT_RSA_PUBLIC_FORMAT_RAW && !is_string($key)) {
return false;
}
switch ($type) {
case CRYPT_RSA_PUBLIC_FORMAT_RAW:
if (!is_array($key)) {
return false;
}
$components = array();
switch (true) {
case isset($key['e']):
$components['publicExponent'] = $key['e']->copy();
break;
case isset($key['exponent']):
$components['publicExponent'] = $key['exponent']->copy();
break;
case isset($key['publicExponent']):
$components['publicExponent'] = $key['publicExponent']->copy();
break;
case isset($key[0]):
$components['publicExponent'] = $key[0]->copy();
}
switch (true) {
case isset($key['n']):
$components['modulus'] = $key['n']->copy();
break;
case isset($key['modulo']):
$components['modulus'] = $key['modulo']->copy();
break;
case isset($key['modulus']):
$components['modulus'] = $key['modulus']->copy();
break;
case isset($key[1]):
$components['modulus'] = $key[1]->copy();
}
return isset($components['modulus']) && isset($components['publicExponent']) ? $components : false;
case CRYPT_RSA_PRIVATE_FORMAT_PKCS1:
case CRYPT_RSA_PUBLIC_FORMAT_PKCS1:
/* Although PKCS#1 proposes a format that public and private keys can use, encrypting them is
"outside the scope" of PKCS#1. PKCS#1 then refers you to PKCS#12 and PKCS#15 if you're wanting to
protect private keys, however, that's not what OpenSSL* does. OpenSSL protects private keys by adding
two new "fields" to the key - DEK-Info and Proc-Type. These fields are discussed here:
http://tools.ietf.org/html/rfc1421#section-4.6.1.1
http://tools.ietf.org/html/rfc1421#section-4.6.1.3
DES-EDE3-CBC as an algorithm, however, is not discussed anywhere, near as I can tell.
DES-CBC and DES-EDE are discussed in RFC1423, however, DES-EDE3-CBC isn't, nor is its key derivation
function. As is, the definitive authority on this encoding scheme isn't the IETF but rather OpenSSL's
own implementation. ie. the implementation *is* the standard and any bugs that may exist in that
implementation are part of the standard, as well.
* OpenSSL is the de facto standard. It's utilized by OpenSSH and other projects */
if (preg_match('#DEK-Info: (.+),(.+)#', $key, $matches)) {
$iv = pack('H*', trim($matches[2]));
$symkey = pack('H*', md5($this->password . substr($iv, 0, 8))); // symkey is short for symmetric key
$symkey.= substr(pack('H*', md5($symkey . $this->password . $iv)), 0, 8);
$ciphertext = preg_replace('#.+(\r|\n|\r\n)\1|[\r\n]|-.+-#s', '', $key);
$ciphertext = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $ciphertext) ? base64_decode($ciphertext) : false;
if ($ciphertext === false) {
$ciphertext = $key;
}
switch ($matches[1]) {
case 'AES-128-CBC':
if (!class_exists('Crypt_AES')) {
require_once('Crypt/AES.php');
}
$symkey = substr($symkey, 0, 16);
$crypto = new Crypt_AES();
break;
case 'DES-EDE3-CFB':
if (!class_exists('Crypt_TripleDES')) {
require_once('Crypt/TripleDES.php');
}
$crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CFB);
break;
case 'DES-EDE3-CBC':
if (!class_exists('Crypt_TripleDES')) {
require_once('Crypt/TripleDES.php');
}
$crypto = new Crypt_TripleDES();
break;
case 'DES-CBC':
if (!class_exists('Crypt_DES')) {
require_once('Crypt/DES.php');
}
$crypto = new Crypt_DES();
break;
default:
return false;
}
$crypto->setKey($symkey);
$crypto->setIV($iv);
$decoded = $crypto->decrypt($ciphertext);
} else {
$decoded = preg_replace('#-.+-|[\r\n]#', '', $key);
$decoded = preg_match('#^[a-zA-Z\d/+]*={0,2}$#', $decoded) ? base64_decode($decoded) : false;
}
if ($decoded !== false) {
$key = $decoded;
}
$components = array();
if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
return false;
}
if ($this->_decodeLength($key) != strlen($key)) {
return false;
}
$tag = ord($this->_string_shift($key));
/* intended for keys for which OpenSSL's asn1parse returns the following:
0:d=0 hl=4 l= 631 cons: SEQUENCE
4:d=1 hl=2 l= 1 prim: INTEGER :00
7:d=1 hl=2 l= 13 cons: SEQUENCE
9:d=2 hl=2 l= 9 prim: OBJECT :rsaEncryption
20:d=2 hl=2 l= 0 prim: NULL
22:d=1 hl=4 l= 609 prim: OCTET STRING */
if ($tag == CRYPT_RSA_ASN1_INTEGER && substr($key, 0, 3) == "\x01\x00\x30") {
$this->_string_shift($key, 3);
$tag = CRYPT_RSA_ASN1_SEQUENCE;
}
if ($tag == CRYPT_RSA_ASN1_SEQUENCE) {
/* intended for keys for which OpenSSL's asn1parse returns the following:
0:d=0 hl=4 l= 290 cons: SEQUENCE
4:d=1 hl=2 l= 13 cons: SEQUENCE
6:d=2 hl=2 l= 9 prim: OBJECT :rsaEncryption
17:d=2 hl=2 l= 0 prim: NULL
19:d=1 hl=4 l= 271 prim: BIT STRING */
$this->_string_shift($key, $this->_decodeLength($key));
$tag = ord($this->_string_shift($key)); // skip over the BIT STRING / OCTET STRING tag
$this->_decodeLength($key); // skip over the BIT STRING / OCTET STRING length
// "The initial octet shall encode, as an unsigned binary integer wtih bit 1 as the least significant bit, the number of
// unused bits in the final subsequent octet. The number shall be in the range zero to seven."
// -- http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf (section 8.6.2.2)
if ($tag == CRYPT_RSA_ASN1_BITSTRING) {
$this->_string_shift($key);
}
if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
return false;
}
if ($this->_decodeLength($key) != strlen($key)) {
return false;
}
$tag = ord($this->_string_shift($key));
}
if ($tag != CRYPT_RSA_ASN1_INTEGER) {
return false;
}
$length = $this->_decodeLength($key);
$temp = $this->_string_shift($key, $length);
if (strlen($temp) != 1 || ord($temp) > 2) {
$components['modulus'] = new Math_BigInteger($temp, -256);
$this->_string_shift($key); // skip over CRYPT_RSA_ASN1_INTEGER
$length = $this->_decodeLength($key);
$components[$type == CRYPT_RSA_PUBLIC_FORMAT_PKCS1 ? 'publicExponent' : 'privateExponent'] = new Math_BigInteger($this->_string_shift($key, $length), -256);
return $components;
}
if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_INTEGER) {
return false;
}
$length = $this->_decodeLength($key);
$components['modulus'] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['publicExponent'] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['privateExponent'] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['primes'] = array(1 => new Math_BigInteger($this->_string_shift($key, $length), -256));
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['primes'][] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['exponents'] = array(1 => new Math_BigInteger($this->_string_shift($key, $length), -256));
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['exponents'][] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['coefficients'] = array(2 => new Math_BigInteger($this->_string_shift($key, $length), -256));
if (!empty($key)) {
if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
return false;
}
$this->_decodeLength($key);
while (!empty($key)) {
if (ord($this->_string_shift($key)) != CRYPT_RSA_ASN1_SEQUENCE) {
return false;
}
$this->_decodeLength($key);
$key = substr($key, 1);
$length = $this->_decodeLength($key);
$components['primes'][] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['exponents'][] = new Math_BigInteger($this->_string_shift($key, $length), -256);
$this->_string_shift($key);
$length = $this->_decodeLength($key);
$components['coefficients'][] = new Math_BigInteger($this->_string_shift($key, $length), -256);
}
}
return $components;
case CRYPT_RSA_PUBLIC_FORMAT_OPENSSH:
$key = base64_decode(preg_replace('#^ssh-rsa | .+$#', '', $key));
if ($key === false) {
return false;
}
$cleanup = substr($key, 0, 11) == "\0\0\0\7ssh-rsa";
if (strlen($key) <= 4) {
return false;
}
extract(unpack('Nlength', $this->_string_shift($key, 4)));
$publicExponent = new Math_BigInteger($this->_string_shift($key, $length), -256);
if (strlen($key) <= 4) {
return false;
}
extract(unpack('Nlength', $this->_string_shift($key, 4)));
$modulus = new Math_BigInteger($this->_string_shift($key, $length), -256);
if ($cleanup && strlen($key)) {
if (strlen($key) <= 4) {
return false;
}
extract(unpack('Nlength', $this->_string_shift($key, 4)));
$realModulus = new Math_BigInteger($this->_string_shift($key, $length), -256);
return strlen($key) ? false : array(
'modulus' => $realModulus,
'publicExponent' => $modulus
);
} else {
return strlen($key) ? false : array(
'modulus' => $modulus,
'publicExponent' => $publicExponent
);
}
// http://www.w3.org/TR/xmldsig-core/#sec-RSAKeyValue
// http://en.wikipedia.org/wiki/XML_Signature
case CRYPT_RSA_PRIVATE_FORMAT_XML:
case CRYPT_RSA_PUBLIC_FORMAT_XML:
$this->components = array();
$xml = xml_parser_create('UTF-8');
xml_set_object($xml, $this);
xml_set_element_handler($xml, '_start_element_handler', '_stop_element_handler');
xml_set_character_data_handler($xml, '_data_handler');
if (!xml_parse($xml, $key)) {
return false;
}
return isset($this->components['modulus']) && isset($this->components['publicExponent']) ? $this->components : false;
// from PuTTY's SSHPUBK.C
case CRYPT_RSA_PRIVATE_FORMAT_PUTTY:
$components = array();
$key = preg_split('#\r\n|\r|\n#', $key);
$type = trim(preg_replace('#PuTTY-User-Key-File-2: (.+)#', '$1', $key[0]));
if ($type != 'ssh-rsa') {
return false;
}
$encryption = trim(preg_replace('#Encryption: (.+)#', '$1', $key[1]));
$publicLength = trim(preg_replace('#Public-Lines: (\d+)#', '$1', $key[3]));
$public = base64_decode(implode('', array_map('trim', array_slice($key, 4, $publicLength))));
$public = substr($public, 11);
extract(unpack('Nlength', $this->_string_shift($public, 4)));
$components['publicExponent'] = new Math_BigInteger($this->_string_shift($public, $length), -256);
extract(unpack('Nlength', $this->_string_shift($public, 4)));
$components['modulus'] = new Math_BigInteger($this->_string_shift($public, $length), -256);
$privateLength = trim(preg_replace('#Private-Lines: (\d+)#', '$1', $key[$publicLength + 4]));
$private = base64_decode(implode('', array_map('trim', array_slice($key, $publicLength + 5, $privateLength))));
switch ($encryption) {
case 'aes256-cbc':
if (!class_exists('Crypt_AES')) {
require_once('Crypt/AES.php');
}
$symkey = '';
$sequence = 0;
while (strlen($symkey) < 32) {
$temp = pack('Na*', $sequence++, $this->password);
$symkey.= pack('H*', sha1($temp));
}
$symkey = substr($symkey, 0, 32);
$crypto = new Crypt_AES();
}
if ($encryption != 'none') {
$crypto->setKey($symkey);
$crypto->disablePadding();
$private = $crypto->decrypt($private);
if ($private === false) {
return false;
}
}
extract(unpack('Nlength', $this->_string_shift($private, 4)));
if (strlen($private) < $length) {
return false;
}
$components['privateExponent'] = new Math_BigInteger($this->_string_shift($private, $length), -256);
extract(unpack('Nlength', $this->_string_shift($private, 4)));
if (strlen($private) < $length) {
return false;
}
$components['primes'] = array(1 => new Math_BigInteger($this->_string_shift($private, $length), -256));
extract(unpack('Nlength', $this->_string_shift($private, 4)));
if (strlen($private) < $length) {
return false;
}
$components['primes'][] = new Math_BigInteger($this->_string_shift($private, $length), -256);
$temp = $components['primes'][1]->subtract($this->one);
$components['exponents'] = array(1 => $components['publicExponent']->modInverse($temp));
$temp = $components['primes'][2]->subtract($this->one);
$components['exponents'][] = $components['publicExponent']->modInverse($temp);
extract(unpack('Nlength', $this->_string_shift($private, 4)));
if (strlen($private) < $length) {
return false;
}
$components['coefficients'] = array(2 => new Math_BigInteger($this->_string_shift($private, $length), -256));
return $components;
}
}
/**
* Start Element Handler
*
* Called by xml_set_element_handler()
*
* @access private
* @param Resource $parser
* @param String $name
* @param Array $attribs
*/
function _start_element_handler($parser, $name, $attribs)
{
//$name = strtoupper($name);
switch ($name) {
case 'MODULUS':
$this->current = &$this->components['modulus'];
break;
case 'EXPONENT':
$this->current = &$this->components['publicExponent'];
break;
case 'P':
$this->current = &$this->components['primes'][1];
break;
case 'Q':
$this->current = &$this->components['primes'][2];
break;
case 'DP':
$this->current = &$this->components['exponents'][1];
break;
case 'DQ':
$this->current = &$this->components['exponents'][2];
break;
case 'INVERSEQ':
$this->current = &$this->components['coefficients'][2];
break;
case 'D':
$this->current = &$this->components['privateExponent'];
break;
default:
unset($this->current);
}
$this->current = '';
}
/**
* Stop Element Handler
*
* Called by xml_set_element_handler()
*
* @access private
* @param Resource $parser
* @param String $name
*/
function _stop_element_handler($parser, $name)
{
//$name = strtoupper($name);
if ($name == 'RSAKEYVALUE') {
return;
}
$this->current = new Math_BigInteger(base64_decode($this->current), 256);
}
/**
* Data Handler
*
* Called by xml_set_character_data_handler()
*
* @access private
* @param Resource $parser
* @param String $data
*/
function _data_handler($parser, $data)
{
if (!isset($this->current) || is_object($this->current)) {
return;
}
$this->current.= trim($data);
}
/**
* Loads a public or private key
*
* Returns true on success and false on failure (ie. an incorrect password was provided or the key was malformed)
*
* @access public
* @param String $key
* @param Integer $type optional
*/
function loadKey($key, $type = false)
{
if ($type === false) {
$types = array(
CRYPT_RSA_PUBLIC_FORMAT_RAW,
CRYPT_RSA_PRIVATE_FORMAT_PKCS1,
CRYPT_RSA_PRIVATE_FORMAT_XML,
CRYPT_RSA_PRIVATE_FORMAT_PUTTY,
CRYPT_RSA_PUBLIC_FORMAT_OPENSSH
);
foreach ($types as $type) {
$components = $this->_parseKey($key, $type);
if ($components !== false) {
break;
}
}
} else {
$components = $this->_parseKey($key, $type);
}
if ($components === false) {
return false;
}
$this->modulus = $components['modulus'];
$this->k = strlen($this->modulus->toBytes());
$this->exponent = isset($components['privateExponent']) ? $components['privateExponent'] : $components['publicExponent'];
if (isset($components['primes'])) {
$this->primes = $components['primes'];
$this->exponents = $components['exponents'];
$this->coefficients = $components['coefficients'];
$this->publicExponent = $components['publicExponent'];
} else {
$this->primes = array();
$this->exponents = array();
$this->coefficients = array();
$this->publicExponent = false;
}
return true;
}
/**
* Sets the password
*
* Private keys can be encrypted with a password. To unset the password, pass in the empty string or false.
* Or rather, pass in $password such that empty($password) && !is_string($password) is true.
*
* @see createKey()
* @see loadKey()
* @access public
* @param String $password
*/
function setPassword($password = false)
{
$this->password = $password;
}
/**
* Defines the public key
*
* Some private key formats define the public exponent and some don't. Those that don't define it are problematic when
* used in certain contexts. For example, in SSH-2, RSA authentication works by sending the public key along with a
* message signed by the private key to the server. The SSH-2 server looks the public key up in an index of public keys
* and if it's present then proceeds to verify the signature. Problem is, if your private key doesn't include the public
* exponent this won't work unless you manually add the public exponent.
*
* Do note that when a new key is loaded the index will be cleared.
*
* Returns true on success, false on failure
*
* @see getPublicKey()
* @access public
* @param String $key optional
* @param Integer $type optional
* @return Boolean
*/
function setPublicKey($key = false, $type = false)
{
if ($key === false && !empty($this->modulus)) {
$this->publicExponent = $this->exponent;
return true;
}
if ($type === false) {
$types = array(
CRYPT_RSA_PUBLIC_FORMAT_RAW,
CRYPT_RSA_PUBLIC_FORMAT_PKCS1,
CRYPT_RSA_PUBLIC_FORMAT_XML,
CRYPT_RSA_PUBLIC_FORMAT_OPENSSH
);
foreach ($types as $type) {
$components = $this->_parseKey($key, $type);
if ($components !== false) {
break;
}
}
} else {
$components = $this->_parseKey($key, $type);
}
if ($components === false) {
return false;
}
if (empty($this->modulus) || !$this->modulus->equals($components['modulus'])) {
$this->modulus = $components['modulus'];
$this->exponent = $this->publicExponent = $components['publicExponent'];
return true;
}
$this->publicExponent = $components['publicExponent'];
return true;
}
/**
* Returns the public key
*
* The public key is only returned under two circumstances - if the private key had the public key embedded within it
* or if the public key was set via setPublicKey(). If the currently loaded key is supposed to be the public key this
* function won't return it since this library, for the most part, doesn't distinguish between public and private keys.
*
* @see getPublicKey()
* @access public
* @param String $key
* @param Integer $type optional
*/
function getPublicKey($type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
{
if (empty($this->modulus) || empty($this->publicExponent)) {
return false;
}
$oldFormat = $this->publicKeyFormat;
$this->publicKeyFormat = $type;
$temp = $this->_convertPublicKey($this->modulus, $this->publicExponent);
$this->publicKeyFormat = $oldFormat;
return $temp;
}
/**
* Returns the private key
*
* The private key is only returned if the currently loaded key contains the constituent prime numbers.
*
* @see getPublicKey()
* @access public
* @param String $key
* @param Integer $type optional
*/
function getPrivateKey($type = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
{
if (empty($this->primes)) {
return false;
}
$oldFormat = $this->privateKeyFormat;
$this->privateKeyFormat = $type;
$temp = $this->_convertPrivateKey($this->modulus, $this->publicExponent, $this->exponent, $this->primes, $this->exponents, $this->coefficients);
$this->privateKeyFormat = $oldFormat;
return $temp;
}
/**
* Returns a minimalistic private key
*
* Returns the private key without the prime number constituants. Structurally identical to a public key that
* hasn't been set as the public key
*
* @see getPrivateKey()
* @access private
* @param String $key
* @param Integer $type optional
*/
function _getPrivatePublicKey($mode = CRYPT_RSA_PUBLIC_FORMAT_PKCS1)
{
if (empty($this->modulus) || empty($this->exponent)) {
return false;
}
$oldFormat = $this->publicKeyFormat;
$this->publicKeyFormat = $mode;
$temp = $this->_convertPublicKey($this->modulus, $this->exponent);
$this->publicKeyFormat = $oldFormat;
return $temp;
}
/**
* __toString() magic method
*
* @access public
*/
function __toString()
{
$key = $this->getPrivateKey($this->privateKeyFormat);
if ($key !== false) {
return $key;
}
$key = $this->_getPrivatePublicKey($this->publicKeyFormat);
return $key !== false ? $key : '';
}
/**
* Generates the smallest and largest numbers requiring $bits bits
*
* @access private
* @param Integer $bits
* @return Array
*/
function _generateMinMax($bits)
{
$bytes = $bits >> 3;
$min = str_repeat(chr(0), $bytes);
$max = str_repeat(chr(0xFF), $bytes);
$msb = $bits & 7;
if ($msb) {
$min = chr(1 << ($msb - 1)) . $min;
$max = chr((1 << $msb) - 1) . $max;
} else {
$min[0] = chr(0x80);
}
return array(
'min' => new Math_BigInteger($min, 256),
'max' => new Math_BigInteger($max, 256)
);
}
/**
* DER-decode the length
*
* DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4. See
* {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13 X.690 <20> 8.1.3} for more information.
*
* @access private
* @param String $string
* @return Integer
*/
function _decodeLength(&$string)
{
$length = ord($this->_string_shift($string));
if ( $length & 0x80 ) { // definite length, long form
$length&= 0x7F;
$temp = $this->_string_shift($string, $length);
list(, $length) = unpack('N', substr(str_pad($temp, 4, chr(0), STR_PAD_LEFT), -4));
}
return $length;
}
/**
* DER-encode the length
*
* DER supports lengths up to (2**8)**127, however, we'll only support lengths up to (2**8)**4. See
* {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13 X.690 <20> 8.1.3} for more information.
*
* @access private
* @param Integer $length
* @return String
*/
function _encodeLength($length)
{
if ($length <= 0x7F) {
return chr($length);
}
$temp = ltrim(pack('N', $length), chr(0));
return pack('Ca*', 0x80 | strlen($temp), $temp);
}
/**
* String Shift
*
* Inspired by array_shift
*
* @param String $string
* @param optional Integer $index
* @return String
* @access private
*/
function _string_shift(&$string, $index = 1)
{
$substr = substr($string, 0, $index);
$string = substr($string, $index);
return $substr;
}
/**
* Determines the private key format
*
* @see createKey()
* @access public
* @param Integer $format
*/
function setPrivateKeyFormat($format)
{
$this->privateKeyFormat = $format;
}
/**
* Determines the public key format
*
* @see createKey()
* @access public
* @param Integer $format
*/
function setPublicKeyFormat($format)
{
$this->publicKeyFormat = $format;
}
/**
* Determines which hashing function should be used
*
* Used with signature production / verification and (if the encryption mode is CRYPT_RSA_ENCRYPTION_OAEP) encryption and
* decryption. If $hash isn't supported, sha1 is used.
*
* @access public
* @param String $hash
*/
function setHash($hash)
{
// Crypt_Hash supports algorithms that PKCS#1 doesn't support. md5-96 and sha1-96, for example.
switch ($hash) {
case 'md2':
case 'md5':
case 'sha1':
case 'sha256':
case 'sha384':
case 'sha512':
$this->hash = new Crypt_Hash($hash);
$this->hashName = $hash;
break;
default:
$this->hash = new Crypt_Hash('sha1');
$this->hashName = 'sha1';
}
$this->hLen = $this->hash->getLength();
}
/**
* Determines which hashing function should be used for the mask generation function
*
* The mask generation function is used by CRYPT_RSA_ENCRYPTION_OAEP and CRYPT_RSA_SIGNATURE_PSS and although it's
* best if Hash and MGFHash are set to the same thing this is not a requirement.
*
* @access public
* @param String $hash
*/
function setMGFHash($hash)
{
// Crypt_Hash supports algorithms that PKCS#1 doesn't support. md5-96 and sha1-96, for example.
switch ($hash) {
case 'md2':
case 'md5':
case 'sha1':
case 'sha256':
case 'sha384':
case 'sha512':
$this->mgfHash = new Crypt_Hash($hash);
break;
default:
$this->mgfHash = new Crypt_Hash('sha1');
}
$this->mgfHLen = $this->mgfHash->getLength();
}
/**
* Determines the salt length
*
* To quote from {@link http://tools.ietf.org/html/rfc3447#page-38 RFC3447#page-38}:
*
* Typical salt lengths in octets are hLen (the length of the output
* of the hash function Hash) and 0.
*
* @access public
* @param Integer $format
*/
function setSaltLength($sLen)
{
$this->sLen = $sLen;
}
/**
* Generates a random string x bytes long
*
* @access public
* @param Integer $bytes
* @param optional Integer $nonzero
* @return String
*/
function _random($bytes, $nonzero = false)
{
$temp = '';
for ($i = 0; $i < $bytes; $i++) {
$temp.= chr(crypt_random($nonzero, 255));
}
return $temp;
}
/**
* Integer-to-Octet-String primitive
*
* See {@link http://tools.ietf.org/html/rfc3447#section-4.1 RFC3447#section-4.1}.
*
* @access private
* @param Math_BigInteger $x
* @param Integer $xLen
* @return String
*/
function _i2osp($x, $xLen)
{
$x = $x->toBytes();
if (strlen($x) > $xLen) {
user_error('Integer too large', E_USER_NOTICE);
return false;
}
return str_pad($x, $xLen, chr(0), STR_PAD_LEFT);
}
/**
* Octet-String-to-Integer primitive
*
* See {@link http://tools.ietf.org/html/rfc3447#section-4.2 RFC3447#section-4.2}.
*
* @access private
* @param String $x
* @return Math_BigInteger
*/
function _os2ip($x)
{
return new Math_BigInteger($x, 256);
}
/**
* Exponentiate with or without Chinese Remainder Theorem
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.1.1 RFC3447#section-5.1.2}.
*
* @access private
* @param Math_BigInteger $x
* @return Math_BigInteger
*/
function _exponentiate($x)
{
if (empty($this->primes) || empty($this->coefficients) || empty($this->exponents)) {
return $x->modPow($this->exponent, $this->modulus);
}
$num_primes = count($this->primes);
if (defined('CRYPT_RSA_DISABLE_BLINDING')) {
$m_i = array(
1 => $x->modPow($this->exponents[1], $this->primes[1]),
2 => $x->modPow($this->exponents[2], $this->primes[2])
);
$h = $m_i[1]->subtract($m_i[2]);
$h = $h->multiply($this->coefficients[2]);
list(, $h) = $h->divide($this->primes[1]);
$m = $m_i[2]->add($h->multiply($this->primes[2]));
$r = $this->primes[1];
for ($i = 3; $i <= $num_primes; $i++) {
$m_i = $x->modPow($this->exponents[$i], $this->primes[$i]);
$r = $r->multiply($this->primes[$i - 1]);
$h = $m_i->subtract($m);
$h = $h->multiply($this->coefficients[$i]);
list(, $h) = $h->divide($this->primes[$i]);
$m = $m->add($r->multiply($h));
}
} else {
$smallest = $this->primes[1];
for ($i = 2; $i <= $num_primes; $i++) {
if ($smallest->compare($this->primes[$i]) > 0) {
$smallest = $this->primes[$i];
}
}
$one = new Math_BigInteger(1);
$one->setRandomGenerator('crypt_random');
$r = $one->random($one, $smallest->subtract($one));
$m_i = array(
1 => $this->_blind($x, $r, 1),
2 => $this->_blind($x, $r, 2)
);
$h = $m_i[1]->subtract($m_i[2]);
$h = $h->multiply($this->coefficients[2]);
list(, $h) = $h->divide($this->primes[1]);
$m = $m_i[2]->add($h->multiply($this->primes[2]));
$r = $this->primes[1];
for ($i = 3; $i <= $num_primes; $i++) {
$m_i = $this->_blind($x, $r, $i);
$r = $r->multiply($this->primes[$i - 1]);
$h = $m_i->subtract($m);
$h = $h->multiply($this->coefficients[$i]);
list(, $h) = $h->divide($this->primes[$i]);
$m = $m->add($r->multiply($h));
}
}
return $m;
}
/**
* Performs RSA Blinding
*
* Protects against timing attacks by employing RSA Blinding.
* Returns $x->modPow($this->exponents[$i], $this->primes[$i])
*
* @access private
* @param Math_BigInteger $x
* @param Math_BigInteger $r
* @param Integer $i
* @return Math_BigInteger
*/
function _blind($x, $r, $i)
{
$x = $x->multiply($r->modPow($this->publicExponent, $this->primes[$i]));
$x = $x->modPow($this->exponents[$i], $this->primes[$i]);
$r = $r->modInverse($this->primes[$i]);
$x = $x->multiply($r);
list(, $x) = $x->divide($this->primes[$i]);
return $x;
}
/**
* Performs blinded RSA equality testing
*
* Protects against a particular type of timing attack described.
*
* See {@link http://codahale.com/a-lesson-in-timing-attacks/ A Lesson In Timing Attacks (or, Don<6F>t use MessageDigest.isEquals)}
*
* Thanks for the heads up singpolyma!
*
* @access private
* @param String $x
* @param String $y
* @return Boolean
*/
function _equals($x, $y)
{
if (strlen($x) != strlen($y)) {
return false;
}
$result = 0;
for ($i = 0; $i < strlen($x); $i++) {
$result |= $x[$i] ^ $y[$i];
}
return $result == 0;
}
/**
* RSAEP
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.1.1 RFC3447#section-5.1.1}.
*
* @access private
* @param Math_BigInteger $m
* @return Math_BigInteger
*/
function _rsaep($m)
{
if ($m->compare($this->zero) < 0 || $m->compare($this->modulus) > 0) {
user_error('Message representative out of range', E_USER_NOTICE);
return false;
}
return $this->_exponentiate($m);
}
/**
* RSADP
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.1.2 RFC3447#section-5.1.2}.
*
* @access private
* @param Math_BigInteger $c
* @return Math_BigInteger
*/
function _rsadp($c)
{
if ($c->compare($this->zero) < 0 || $c->compare($this->modulus) > 0) {
user_error('Ciphertext representative out of range', E_USER_NOTICE);
return false;
}
return $this->_exponentiate($c);
}
/**
* RSASP1
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.2.1 RFC3447#section-5.2.1}.
*
* @access private
* @param Math_BigInteger $m
* @return Math_BigInteger
*/
function _rsasp1($m)
{
if ($m->compare($this->zero) < 0 || $m->compare($this->modulus) > 0) {
user_error('Message representative out of range', E_USER_NOTICE);
return false;
}
return $this->_exponentiate($m);
}
/**
* RSAVP1
*
* See {@link http://tools.ietf.org/html/rfc3447#section-5.2.2 RFC3447#section-5.2.2}.
*
* @access private
* @param Math_BigInteger $s
* @return Math_BigInteger
*/
function _rsavp1($s)
{
if ($s->compare($this->zero) < 0 || $s->compare($this->modulus) > 0) {
user_error('Signature representative out of range', E_USER_NOTICE);
return false;
}
return $this->_exponentiate($s);
}
/**
* MGF1
*
* See {@link http://tools.ietf.org/html/rfc3447#appendix-B.2.1 RFC3447#appendix-B.2.1}.
*
* @access private
* @param String $mgfSeed
* @param Integer $mgfLen
* @return String
*/
function _mgf1($mgfSeed, $maskLen)
{
// if $maskLen would yield strings larger than 4GB, PKCS#1 suggests a "Mask too long" error be output.
$t = '';
$count = ceil($maskLen / $this->mgfHLen);
for ($i = 0; $i < $count; $i++) {
$c = pack('N', $i);
$t.= $this->mgfHash->hash($mgfSeed . $c);
}
return substr($t, 0, $maskLen);
}
/**
* RSAES-OAEP-ENCRYPT
*
* See {@link http://tools.ietf.org/html/rfc3447#section-7.1.1 RFC3447#section-7.1.1} and
* {http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding OAES}.
*
* @access private
* @param String $m
* @param String $l
* @return String
*/
function _rsaes_oaep_encrypt($m, $l = '')
{
$mLen = strlen($m);
// Length checking
// if $l is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
// be output.
if ($mLen > $this->k - 2 * $this->hLen - 2) {
user_error('Message too long', E_USER_NOTICE);
return false;
}
// EME-OAEP encoding
$lHash = $this->hash->hash($l);
$ps = str_repeat(chr(0), $this->k - $mLen - 2 * $this->hLen - 2);
$db = $lHash . $ps . chr(1) . $m;
$seed = $this->_random($this->hLen);
$dbMask = $this->_mgf1($seed, $this->k - $this->hLen - 1);
$maskedDB = $db ^ $dbMask;
$seedMask = $this->_mgf1($maskedDB, $this->hLen);
$maskedSeed = $seed ^ $seedMask;
$em = chr(0) . $maskedSeed . $maskedDB;
// RSA encryption
$m = $this->_os2ip($em);
$c = $this->_rsaep($m);
$c = $this->_i2osp($c, $this->k);
// Output the ciphertext C
return $c;
}
/**
* RSAES-OAEP-DECRYPT
*
* See {@link http://tools.ietf.org/html/rfc3447#section-7.1.2 RFC3447#section-7.1.2}. The fact that the error
* messages aren't distinguishable from one another hinders debugging, but, to quote from RFC3447#section-7.1.2:
*
* Note. Care must be taken to ensure that an opponent cannot
* distinguish the different error conditions in Step 3.g, whether by
* error message or timing, or, more generally, learn partial
* information about the encoded message EM. Otherwise an opponent may
* be able to obtain useful information about the decryption of the
* ciphertext C, leading to a chosen-ciphertext attack such as the one
* observed by Manger [36].
*
* As for $l... to quote from {@link http://tools.ietf.org/html/rfc3447#page-17 RFC3447#page-17}:
*
* Both the encryption and the decryption operations of RSAES-OAEP take
* the value of a label L as input. In this version of PKCS #1, L is
* the empty string; other uses of the label are outside the scope of
* this document.
*
* @access private
* @param String $c
* @param String $l
* @return String
*/
function _rsaes_oaep_decrypt($c, $l = '')
{
// Length checking
// if $l is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
// be output.
if (strlen($c) != $this->k || $this->k < 2 * $this->hLen + 2) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
// RSA decryption
$c = $this->_os2ip($c);
$m = $this->_rsadp($c);
if ($m === false) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
$em = $this->_i2osp($m, $this->k);
// EME-OAEP decoding
$lHash = $this->hash->hash($l);
$y = ord($em[0]);
$maskedSeed = substr($em, 1, $this->hLen);
$maskedDB = substr($em, $this->hLen + 1);
$seedMask = $this->_mgf1($maskedDB, $this->hLen);
$seed = $maskedSeed ^ $seedMask;
$dbMask = $this->_mgf1($seed, $this->k - $this->hLen - 1);
$db = $maskedDB ^ $dbMask;
$lHash2 = substr($db, 0, $this->hLen);
$m = substr($db, $this->hLen);
if ($lHash != $lHash2) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
$m = ltrim($m, chr(0));
if (ord($m[0]) != 1) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
// Output the message M
return substr($m, 1);
}
/**
* RSAES-PKCS1-V1_5-ENCRYPT
*
* See {@link http://tools.ietf.org/html/rfc3447#section-7.2.1 RFC3447#section-7.2.1}.
*
* @access private
* @param String $m
* @return String
*/
function _rsaes_pkcs1_v1_5_encrypt($m)
{
$mLen = strlen($m);
// Length checking
if ($mLen > $this->k - 11) {
user_error('Message too long', E_USER_NOTICE);
return false;
}
// EME-PKCS1-v1_5 encoding
$ps = $this->_random($this->k - $mLen - 3, true);
$em = chr(0) . chr(2) . $ps . chr(0) . $m;
// RSA encryption
$m = $this->_os2ip($em);
$c = $this->_rsaep($m);
$c = $this->_i2osp($c, $this->k);
// Output the ciphertext C
return $c;
}
/**
* RSAES-PKCS1-V1_5-DECRYPT
*
* See {@link http://tools.ietf.org/html/rfc3447#section-7.2.2 RFC3447#section-7.2.2}.
*
* For compatability purposes, this function departs slightly from the description given in RFC3447.
* The reason being that RFC2313#section-8.1 (PKCS#1 v1.5) states that ciphertext's encrypted by the
* private key should have the second byte set to either 0 or 1 and that ciphertext's encrypted by the
* public key should have the second byte set to 2. In RFC3447 (PKCS#1 v2.1), the second byte is supposed
* to be 2 regardless of which key is used. For compatability purposes, we'll just check to make sure the
* second byte is 2 or less. If it is, we'll accept the decrypted string as valid.
*
* As a consequence of this, a private key encrypted ciphertext produced with Crypt_RSA may not decrypt
* with a strictly PKCS#1 v1.5 compliant RSA implementation. Public key encrypted ciphertext's should but
* not private key encrypted ciphertext's.
*
* @access private
* @param String $c
* @return String
*/
function _rsaes_pkcs1_v1_5_decrypt($c)
{
// Length checking
if (strlen($c) != $this->k) { // or if k < 11
user_error('Decryption error', E_USER_NOTICE);
return false;
}
// RSA decryption
$c = $this->_os2ip($c);
$m = $this->_rsadp($c);
if ($m === false) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
$em = $this->_i2osp($m, $this->k);
// EME-PKCS1-v1_5 decoding
if (ord($em[0]) != 0 || ord($em[1]) > 2) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
$ps = substr($em, 2, strpos($em, chr(0), 2) - 2);
$m = substr($em, strlen($ps) + 3);
if (strlen($ps) < 8) {
user_error('Decryption error', E_USER_NOTICE);
return false;
}
// Output M
return $m;
}
/**
* EMSA-PSS-ENCODE
*
* See {@link http://tools.ietf.org/html/rfc3447#section-9.1.1 RFC3447#section-9.1.1}.
*
* @access private
* @param String $m
* @param Integer $emBits
*/
function _emsa_pss_encode($m, $emBits)
{
// if $m is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
// be output.
$emLen = ($emBits + 1) >> 3; // ie. ceil($emBits / 8)
$sLen = $this->sLen == false ? $this->hLen : $this->sLen;
$mHash = $this->hash->hash($m);
if ($emLen < $this->hLen + $sLen + 2) {
user_error('Encoding error', E_USER_NOTICE);
return false;
}
$salt = $this->_random($sLen);
$m2 = "\0\0\0\0\0\0\0\0" . $mHash . $salt;
$h = $this->hash->hash($m2);
$ps = str_repeat(chr(0), $emLen - $sLen - $this->hLen - 2);
$db = $ps . chr(1) . $salt;
$dbMask = $this->_mgf1($h, $emLen - $this->hLen - 1);
$maskedDB = $db ^ $dbMask;
$maskedDB[0] = ~chr(0xFF << ($emBits & 7)) & $maskedDB[0];
$em = $maskedDB . $h . chr(0xBC);
return $em;
}
/**
* EMSA-PSS-VERIFY
*
* See {@link http://tools.ietf.org/html/rfc3447#section-9.1.2 RFC3447#section-9.1.2}.
*
* @access private
* @param String $m
* @param String $em
* @param Integer $emBits
* @return String
*/
function _emsa_pss_verify($m, $em, $emBits)
{
// if $m is larger than two million terrabytes and you're using sha1, PKCS#1 suggests a "Label too long" error
// be output.
$emLen = ($emBits + 1) >> 3; // ie. ceil($emBits / 8);
$sLen = $this->sLen == false ? $this->hLen : $this->sLen;
$mHash = $this->hash->hash($m);
if ($emLen < $this->hLen + $sLen + 2) {
return false;
}
if ($em[strlen($em) - 1] != chr(0xBC)) {
return false;
}
$maskedDB = substr($em, 0, -$this->hLen - 1);
$h = substr($em, -$this->hLen - 1, $this->hLen);
$temp = chr(0xFF << ($emBits & 7));
if ((~$maskedDB[0] & $temp) != $temp) {
return false;
}
$dbMask = $this->_mgf1($h, $emLen - $this->hLen - 1);
$db = $maskedDB ^ $dbMask;
$db[0] = ~chr(0xFF << ($emBits & 7)) & $db[0];
$temp = $emLen - $this->hLen - $sLen - 2;
if (substr($db, 0, $temp) != str_repeat(chr(0), $temp) || ord($db[$temp]) != 1) {
return false;
}
$salt = substr($db, $temp + 1); // should be $sLen long
$m2 = "\0\0\0\0\0\0\0\0" . $mHash . $salt;
$h2 = $this->hash->hash($m2);
return $this->_equals($h, $h2);
}
/**
* RSASSA-PSS-SIGN
*
* See {@link http://tools.ietf.org/html/rfc3447#section-8.1.1 RFC3447#section-8.1.1}.
*
* @access private
* @param String $m
* @return String
*/
function _rsassa_pss_sign($m)
{
// EMSA-PSS encoding
$em = $this->_emsa_pss_encode($m, 8 * $this->k - 1);
// RSA signature
$m = $this->_os2ip($em);
$s = $this->_rsasp1($m);
$s = $this->_i2osp($s, $this->k);
// Output the signature S
return $s;
}
/**
* RSASSA-PSS-VERIFY
*
* See {@link http://tools.ietf.org/html/rfc3447#section-8.1.2 RFC3447#section-8.1.2}.
*
* @access private
* @param String $m
* @param String $s
* @return String
*/
function _rsassa_pss_verify($m, $s)
{
// Length checking
if (strlen($s) != $this->k) {
user_error('Invalid signature', E_USER_NOTICE);
return false;
}
// RSA verification
$modBits = 8 * $this->k;
$s2 = $this->_os2ip($s);
$m2 = $this->_rsavp1($s2);
if ($m2 === false) {
user_error('Invalid signature', E_USER_NOTICE);
return false;
}
$em = $this->_i2osp($m2, $modBits >> 3);
if ($em === false) {
user_error('Invalid signature', E_USER_NOTICE);
return false;
}
// EMSA-PSS verification
return $this->_emsa_pss_verify($m, $em, $modBits - 1);
}
/**
* EMSA-PKCS1-V1_5-ENCODE
*
* See {@link http://tools.ietf.org/html/rfc3447#section-9.2 RFC3447#section-9.2}.
*
* @access private
* @param String $m
* @param Integer $emLen
* @return String
*/
function _emsa_pkcs1_v1_5_encode($m, $emLen)
{
$h = $this->hash->hash($m);
if ($h === false) {
return false;
}
// see http://tools.ietf.org/html/rfc3447#page-43
switch ($this->hashName) {
case 'md2':
$t = pack('H*', '3020300c06082a864886f70d020205000410');
break;
case 'md5':
$t = pack('H*', '3020300c06082a864886f70d020505000410');
break;
case 'sha1':
$t = pack('H*', '3021300906052b0e03021a05000414');
break;
case 'sha256':
$t = pack('H*', '3031300d060960864801650304020105000420');
break;
case 'sha384':
$t = pack('H*', '3041300d060960864801650304020205000430');
break;
case 'sha512':
$t = pack('H*', '3051300d060960864801650304020305000440');
}
$t.= $h;
$tLen = strlen($t);
if ($emLen < $tLen + 11) {
user_error('Intended encoded message length too short', E_USER_NOTICE);
return false;
}
$ps = str_repeat(chr(0xFF), $emLen - $tLen - 3);
$em = "\0\1$ps\0$t";
return $em;
}
/**
* RSASSA-PKCS1-V1_5-SIGN
*
* See {@link http://tools.ietf.org/html/rfc3447#section-8.2.1 RFC3447#section-8.2.1}.
*
* @access private
* @param String $m
* @return String
*/
function _rsassa_pkcs1_v1_5_sign($m)
{
// EMSA-PKCS1-v1_5 encoding
$em = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
if ($em === false) {
user_error('RSA modulus too short', E_USER_NOTICE);
return false;
}
// RSA signature
$m = $this->_os2ip($em);
$s = $this->_rsasp1($m);
$s = $this->_i2osp($s, $this->k);
// Output the signature S
return $s;
}
/**
* RSASSA-PKCS1-V1_5-VERIFY
*
* See {@link http://tools.ietf.org/html/rfc3447#section-8.2.2 RFC3447#section-8.2.2}.
*
* @access private
* @param String $m
* @return String
*/
function _rsassa_pkcs1_v1_5_verify($m, $s)
{
// Length checking
if (strlen($s) != $this->k) {
user_error('Invalid signature', E_USER_NOTICE);
return false;
}
// RSA verification
$s = $this->_os2ip($s);
$m2 = $this->_rsavp1($s);
if ($m2 === false) {
user_error('Invalid signature', E_USER_NOTICE);
return false;
}
$em = $this->_i2osp($m2, $this->k);
if ($em === false) {
user_error('Invalid signature', E_USER_NOTICE);
return false;
}
// EMSA-PKCS1-v1_5 encoding
$em2 = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
if ($em2 === false) {
user_error('RSA modulus too short', E_USER_NOTICE);
return false;
}
// Compare
return $this->_equals($em, $em2);
}
/**
* Set Encryption Mode
*
* Valid values include CRYPT_RSA_ENCRYPTION_OAEP and CRYPT_RSA_ENCRYPTION_PKCS1.
*
* @access public
* @param Integer $mode
*/
function setEncryptionMode($mode)
{
$this->encryptionMode = $mode;
}
/**
* Set Signature Mode
*
* Valid values include CRYPT_RSA_SIGNATURE_PSS and CRYPT_RSA_SIGNATURE_PKCS1
*
* @access public
* @param Integer $mode
*/
function setSignatureMode($mode)
{
$this->signatureMode = $mode;
}
/**
* Encryption
*
* Both CRYPT_RSA_ENCRYPTION_OAEP and CRYPT_RSA_ENCRYPTION_PKCS1 both place limits on how long $plaintext can be.
* If $plaintext exceeds those limits it will be broken up so that it does and the resultant ciphertext's will
* be concatenated together.
*
* @see decrypt()
* @access public
* @param String $plaintext
* @return String
*/
function encrypt($plaintext)
{
switch ($this->encryptionMode) {
case CRYPT_RSA_ENCRYPTION_PKCS1:
$length = $this->k - 11;
if ($length <= 0) {
return false;
}
$plaintext = str_split($plaintext, $length);
$ciphertext = '';
foreach ($plaintext as $m) {
$ciphertext.= $this->_rsaes_pkcs1_v1_5_encrypt($m);
}
return $ciphertext;
//case CRYPT_RSA_ENCRYPTION_OAEP:
default:
$length = $this->k - 2 * $this->hLen - 2;
if ($length <= 0) {
return false;
}
$plaintext = str_split($plaintext, $length);
$ciphertext = '';
foreach ($plaintext as $m) {
$ciphertext.= $this->_rsaes_oaep_encrypt($m);
}
return $ciphertext;
}
}
/**
* Decryption
*
* @see encrypt()
* @access public
* @param String $plaintext
* @return String
*/
function decrypt($ciphertext)
{
if ($this->k <= 0) {
return false;
}
$ciphertext = str_split($ciphertext, $this->k);
$plaintext = '';
switch ($this->encryptionMode) {
case CRYPT_RSA_ENCRYPTION_PKCS1:
$decrypt = '_rsaes_pkcs1_v1_5_decrypt';
break;
//case CRYPT_RSA_ENCRYPTION_OAEP:
default:
$decrypt = '_rsaes_oaep_decrypt';
}
foreach ($ciphertext as $c) {
$temp = $this->$decrypt($c);
if ($temp === false) {
return false;
}
$plaintext.= $temp;
}
return $plaintext;
}
/**
* Create a signature
*
* @see verify()
* @access public
* @param String $message
* @return String
*/
function sign($message)
{
if (empty($this->modulus) || empty($this->exponent)) {
return false;
}
switch ($this->signatureMode) {
case CRYPT_RSA_SIGNATURE_PKCS1:
return $this->_rsassa_pkcs1_v1_5_sign($message);
//case CRYPT_RSA_SIGNATURE_PSS:
default:
return $this->_rsassa_pss_sign($message);
}
}
/**
* Verifies a signature
*
* @see sign()
* @access public
* @param String $message
* @param String $signature
* @return Boolean
*/
function verify($message, $signature)
{
if (empty($this->modulus) || empty($this->exponent)) {
return false;
}
switch ($this->signatureMode) {
case CRYPT_RSA_SIGNATURE_PKCS1:
return $this->_rsassa_pkcs1_v1_5_verify($message, $signature);
//case CRYPT_RSA_SIGNATURE_PSS:
default:
return $this->_rsassa_pss_verify($message, $signature);
}
}
}
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