<?php
/**
* Pure-PHP PKCS#1 (v2.1) compliant implementation of RSA.
*
* PHP version 5
*
* Here's an example of how to encrypt and decrypt text with this library:
* <code>
* <?php
* include 'vendor/autoload.php';
*
* extract(\phpseclib\Crypt\RSA::createKey());
*
* $plaintext = 'terrafrost';
*
* $ciphertext = $publickey->encrypt($plaintext);
*
* echo $privatekey->decrypt($ciphertext);
* ?>
* </code>
*
* Here's an example of how to create signatures and verify signatures with this library:
* <code>
* <?php
* include 'vendor/autoload.php';
*
* extract(\phpseclib\Crypt\RSA::createKey());
*
* $plaintext = 'terrafrost';
*
* $signature = $privatekey->sign($plaintext);
*
* echo $publickey->verify($plaintext, $signature) ? 'verified' : 'unverified';
* ?>
* </code>
*
* @category Crypt
* @package RSA
* @author Jim Wigginton <terrafrost@php.net>
* @copyright 2009 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib\Crypt;
use ParagonIE\ConstantTime\Base64;
use phpseclib\File\ASN1;
use phpseclib\Math\BigInteger;
/**
* Pure-PHP PKCS#1 compliant implementation of RSA.
*
* @package RSA
* @author Jim Wigginton <terrafrost@php.net>
* @access public
*/
class RSA
{
/**#@+
* @access public
* @see self::encrypt()
* @see self::decrypt()
*/
/**
* Use {@link http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding Optimal Asymmetric Encryption Padding}
* (OAEP) for encryption / decryption.
*
* Uses sha256 by default
*
* @see self::setHash()
* @see self::setMGFHash()
*/
const PADDING_OAEP = 1;
/**
* Use PKCS#1 padding.
*
* Although self::PADDING_OAEP / self::PADDING_PSS offers more security, including PKCS#1 padding is necessary for purposes of backwards
* compatibility with protocols (like SSH-1) written before OAEP's introduction.
*/
const PADDING_PKCS1 = 2;
/**
* Do not use any padding
*
* Although this method is not recommended it can none-the-less sometimes be useful if you're trying to decrypt some legacy
* stuff, if you're trying to diagnose why an encrypted message isn't decrypting, etc.
*/
const PADDING_NONE = 3;
/**
* Use PKCS#1 padding with PKCS1 v1.5 compatability
*
* A PKCS1 v2.1 encrypted message may not successfully decrypt with a PKCS1 v1.5 implementation (such as OpenSSL).
*/
const PADDING_PKCS15_COMPAT = 6;
/**#@-*/
/**#@+
* @access public
* @see self::sign()
* @see self::verify()
* @see self::setHash()
*/
/**
* Use the Probabilistic Signature Scheme for signing
*
* Uses sha256 and 0 as the salt length
*
* @see self::setSaltLength()
* @see self::setMGFHash()
* @see self::setHash()
*/
const PADDING_PSS = 4;
/**
* Use a relaxed version of PKCS#1 padding for signature verification
*/
const PADDING_RELAXED_PKCS1 = 5;
/**#@-*/
/**#@+
* @access private
* @see self::createKey()
*/
/**
* ASN1 Integer
*/
const ASN1_INTEGER = 2;
/**
* ASN1 Bit String
*/
const ASN1_BITSTRING = 3;
/**
* ASN1 Octet String
*/
const ASN1_OCTETSTRING = 4;
/**
* ASN1 Object Identifier
*/
const ASN1_OBJECT = 6;
/**
* ASN1 Sequence (with the constucted bit set)
*/
const ASN1_SEQUENCE = 48;
/**#@-*/
/**#@+
* @access private
* @see self::__construct()
*/
/**
* To use the pure-PHP implementation
*/
const MODE_INTERNAL = 1;
/**
* To use the OpenSSL library
*
* (if enabled; otherwise, the internal implementation will be used)
*/
const MODE_OPENSSL = 2;
/**#@-*/
/**
* Precomputed Zero
*
* @var array
* @access private
*/
static $zero;
/**
* Precomputed One
*
* @var array
* @access private
*/
static $one;
/**
* Private Key Format
*
* @var string
* @access private
*/
var $privateKeyFormat = 'PKCS1';
/**
* Public Key Format
*
* @var string
* @access private
*/
var $publicKeyFormat = 'PKCS8';
/**
* Modulus (ie. n)
*
* @var \phpseclib\Math\BigInteger
* @access private
*/
var $modulus;
/**
* Modulus length
*
* @var \phpseclib\Math\BigInteger
* @access private
*/
var $k;
/**
* Exponent (ie. e or d)
*
* @var \phpseclib\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 \phpseclib\Crypt\Hash
* @access private
*/
var $hash;
/**
* Length of hash function output
*
* @var int
* @access private
*/
var $hLen;
/**
* Length of salt
*
* @var int
* @access private
*/
var $sLen;
/**
* Hash function for the Mask Generation Function
*
* @var \phpseclib\Crypt\Hash
* @access private
*/
var $mgfHash;
/**
* Length of MGF hash function output
*
* @var int
* @access private
*/
var $mgfHLen;
/**
* Public Exponent
*
* @var mixed
* @access private
*/
var $publicExponent = false;
/**
* Password
*
* @var string
* @access private
*/
var $password = false;
/**
* Loaded File Format
*
* @var string
* @access private
*/
var $format = false;
/**
* OpenSSL configuration file name.
*
* Set to null to use system configuration file.
*
* @see self::createKey()
* @var mixed
* @access public
*/
static $configFile;
/**
* Supported file formats (lower case)
*
* @see self::_initialize_static_variables()
* @var array
* @access private
*/
static $fileFormats = false;
/**
* Supported file formats (original case)
*
* @see self::_initialize_static_variables()
* @var array
* @access private
*/
static $origFileFormats = false;
/**
* Initialize static variables
*
* @access private
*/
static function _initialize_static_variables()
{
if (!isset(self::$zero)) {
self::$zero= new BigInteger(0);
self::$one = new BigInteger(1);
self::$configFile = __DIR__ . '/../openssl.cnf';
if (self::$fileFormats === false) {
self::$fileFormats = array();
foreach (glob(__DIR__ . '/RSA/*.php') as $file) {
$name = pathinfo($file, PATHINFO_FILENAME);
$type = 'phpseclib\Crypt\RSA\\' . $name;
$meta = new \ReflectionClass($type);
if (!$meta->isAbstract()) {
self::$fileFormats[strtolower($name)] = $type;
self::$origFileFormats[] = $name;
}
}
}
}
}
/**
* The constructor
*
* If you want to make use of the openssl extension, you'll need to set the mode manually, yourself. The reason
* \phpseclib\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 \phpseclib\Crypt\RSA
* @access public
*/
function __construct()
{
self::_initialize_static_variables();
$this->hash = new Hash('sha256');
$this->hLen = $this->hash->getLength();
$this->hashName = 'sha256';
$this->mgfHash = new Hash('sha256');
$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 \phpseclib\Crypt\RSA::createKey() as the third parameter for further processing.
*
* @access public
* @param int $bits
* @param int $timeout
* @param array $p
*/
static function createKey($bits = 2048, $timeout = false, $partial = array())
{
self::_initialize_static_variables();
if (!defined('CRYPT_RSA_MODE')) {
switch (true) {
// Math/BigInteger's openssl requirements are a little less stringent than Crypt/RSA's. in particular,
// Math/BigInteger doesn't require an openssl.cfg file whereas Crypt/RSA does. so if Math/BigInteger
// can't use OpenSSL it can be pretty trivially assumed, then, that Crypt/RSA can't either.
case defined('MATH_BIGINTEGER_OPENSSL_DISABLE'):
define('CRYPT_RSA_MODE', self::MODE_INTERNAL);
break;
case extension_loaded('openssl') && file_exists(self::$configFile):
define('CRYPT_RSA_MODE', self::MODE_OPENSSL);
break;
default:
define('CRYPT_RSA_MODE', self::MODE_INTERNAL);
}
}
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 self::MODE_INTERNAL. if CRYPT_RSA_MODE is set to self::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 == self::MODE_OPENSSL && $bits >= 384 && CRYPT_RSA_EXPONENT == 65537) {
$config = array();
if (isset(self::$configFile)) {
$config['config'] = self::$configFile;
}
$rsa = openssl_pkey_new(array('private_key_bits' => $bits) + $config);
openssl_pkey_export($rsa, $privatekeystr, null, $config);
$privatekey = new RSA();
$privatekey->load($privatekeystr);
$publickeyarr = openssl_pkey_get_details($rsa);
$publickey = new RSA();
$publickey->load($publickeyarr['key']);
// 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)) {
$e = new BigInteger(CRYPT_RSA_EXPONENT);
}
extract(self::_generateMinMax($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 {
$num_primes = 2;
}
extract(self::_generateMinMax($temp + $bits % $temp));
$finalMax = $max;
extract(self::_generateMinMax($temp));
$n = clone self::$one;
if (!empty($partial)) {
extract(unserialize($partial));
} else {
$exponents = $coefficients = $primes = array();
$lcm = array(
'top' => clone self::$one,
'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 (!$temp->equals(self::$zero)) {
$min = $min->add(self::$one); // ie. ceil()
}
$primes[$i] = BigInteger::randomPrime($min, $finalMax, $timeout);
} else {
$primes[$i] = BigInteger::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' => false,
'publickey' => false,
'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(self::$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($temp) = $lcm['top']->divide($lcm['bottom']);
$gcd = $temp->gcd($e);
$i0 = 1;
} while (!$gcd->equals(self::$one));
$d = $e->modInverse($temp);
$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
// }
$privatekey = new RSA();
$privatekey->modulus = $n;
$privatekey->k = $bits >> 3;
$privatekey->publicExponent = $e;
$privatekey->exponent = $d;
$privatekey->privateExponent = $e;
$privatekey->primes = $primes;
$privatekey->exponents = $exponents;
$privatekey->coefficients = $coefficients;
$publickey = new RSA();
$publickey->modulus = $n;
$publickey->k = $bits >> 3;
$publickey->exponent = $e;
return array(
'privatekey' => $privatekey,
'publickey' => $publickey,
'partialkey' => false
);
}
/**
* Add a fileformat plugin
*
* The plugin needs to either already be loaded or be auto-loadable.
* Loading a plugin whose shortname overwrite an existing shortname will overwrite the old plugin.
*
* @see self::load()
* @param string $fullname
* @access public
* @return bool
*/
static function addFileFormat($fullname)
{
self::_initialize_static_variables();
if (class_exists($fullname)) {
$meta = new \ReflectionClass($path);
$shortname = $meta->getShortName();
self::$fileFormats[strtolower($shortname)] = $fullname;
self::$origFileFormats[] = $shortname;
}
}
/**
* Returns a list of supported formats.
*
* @access public
* @return array
*/
static function getSupportedFormats()
{
self::_initialize_static_variables();
return self::$origFileFormats;
}
/**
* 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 int $type optional
*/
function load($key, $type = false)
{
if ($key instanceof RSA) {
$this->privateKeyFormat = $key->privateKeyFormat;
$this->publicKeyFormat = $key->publicKeyFormat;
$this->k = $key->k;
$this->hLen = $key->hLen;
$this->sLen = $key->sLen;
$this->mgfHLen = $key->mgfHLen;
$this->password = $key->password;
if (is_object($key->hash)) {
$this->hash = new Hash($key->hash->getHash());
}
if (is_object($key->mgfHash)) {
$this->mgfHash = new Hash($key->mgfHash->getHash());
}
if (is_object($key->modulus)) {
$this->modulus = clone $key->modulus;
}
if (is_object($key->exponent)) {
$this->exponent = clone $key->exponent;
}
if (is_object($key->publicExponent)) {
$this->publicExponent = clone $key->publicExponent;
}
$this->primes = array();
$this->exponents = array();
$this->coefficients = array();
foreach ($this->primes as $prime) {
$this->primes[] = clone $prime;
}
foreach ($this->exponents as $exponent) {
$this->exponents[] = clone $exponent;
}
foreach ($this->coefficients as $coefficient) {
$this->coefficients[] = clone $coefficient;
}
return true;
}
$components = false;
if ($type === false) {
foreach (self::$fileFormats as $format) {
try {
$components = $format::load($key, $this->password);
} catch (\Exception $e) {
$components = false;
}
if ($components !== false) {
break;
}
}
} else {
$format = strtolower($type);
if (isset(self::$fileFormats[$format])) {
$format = self::$fileFormats[$format];
try {
$components = $format::load($key, $this->password);
} catch (\Exception $e) {
$components = false;
}
}
}
if ($components === false) {
$this->format = false;
return false;
}
$this->format = $format;
$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();
$this->publicExponent = false;
}
if ($components['isPublicKey']) {
$this->setPublicKey();
}
return true;
}
/**
* Returns the format of the loaded key.
*
* If the key that was loaded wasn't in a valid or if the key was auto-generated
* with RSA::createKey() then this will return false.
*
* @see self::load()
* @access public
* @return mixed
*/
function getLoadedFormat()
{
if ($this->format === false) {
return false;
}
$meta = new \ReflectionClass($this->format);
return $meta->getShortName();
}
/**
* Returns the private key
*
* The private key is only returned if the currently loaded key contains the constituent prime numbers.
*
* @see self::getPublicKey()
* @access public
* @param string $type optional
* @return mixed
*/
function getPrivateKey($type = 'PKCS1')
{
$type = strtolower($type);
if (!isset(self::$fileFormats[$type])) {
return false;
}
$type = self::$fileFormats[$type];
if (!method_exists($type, 'savePrivateKey')) {
return false;
}
if (empty($this->primes)) {
return false;
}
$oldFormat = $this->privateKeyFormat;
$this->privateKeyFormat = $type;
$temp = $type::savePrivateKey($this->modulus, $this->publicExponent, $this->exponent, $this->primes, $this->exponents, $this->coefficients, $this->password);
$this->privateKeyFormat = $oldFormat;
return $temp;
}
/**
* Returns the key size
*
* More specifically, this returns the size of the modulo in bits.
*
* @access public
* @return int
*/
function getSize()
{
return !isset($this->modulus) ? 0 : strlen($this->modulus->toBits());
}
/**
* 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 self::createKey()
* @see self::load()
* @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. phpseclib tries to guess if the key being used
* is the public key but in the event that it guesses incorrectly you might still want to explicitly set the key as being
* public.
*
* Do note that when a new key is loaded the index will be cleared.
*
* Returns true on success, false on failure
*
* @see self::getPublicKey()
* @access public
* @param string $key optional
* @param int $type optional
* @return bool
*/
function setPublicKey($key = false, $type = false)
{
// if a public key has already been loaded return false
if (!empty($this->publicExponent)) {
return false;
}
if ($key === false && !empty($this->modulus)) {
$this->publicExponent = $this->exponent;
return true;
}
$components = false;
if ($type === false) {
foreach (self::$fileFormats as $format) {
if (!method_exists($format, 'savePublicKey')) {
continue;
}
try {
$components = $format::load($key, $this->password);
} catch (\Exception $e) {
$components = false;
}
if ($components !== false) {
break;
}
}
} else {
$format = strtolower($type);
if (isset(self::$fileFormats[$format])) {
$format = self::$fileFormats[$format];
try {
$components = $format::load($key, $this->password);
} catch (\Exception $e) {
$components = false;
}
}
}
if ($components === false) {
$this->format = false;
return false;
}
$this->format = $format;
if (empty($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;
}
/**
* Defines the private key
*
* If phpseclib guessed a private key was a public key and loaded it as such it might be desirable to force
* phpseclib to treat the key as a private key. This function will do that.
*
* Do note that when a new key is loaded the index will be cleared.
*
* Returns true on success, false on failure
*
* @see self::getPublicKey()
* @access public
* @param string $key optional
* @param int $type optional
* @return bool
*/
function setPrivateKey($key = false, $type = false)
{
if ($key === false && !empty($this->publicExponent)) {
$this->publicExponent = false;
return true;
}
$rsa = new RSA();
if (!$rsa->load($key, $type)) {
return false;
}
$rsa->publicExponent = false;
// don't overwrite the old key if the new key is invalid
$this->load($rsa);
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 self::getPrivateKey()
* @access public
* @param string $type optional
* @return mixed
*/
function getPublicKey($type = 'PKCS8')
{
$type = strtolower($type);
if (!isset(self::$fileFormats[$type])) {
return false;
}
$type = self::$fileFormats[$type];
if (!method_exists($type, 'savePublicKey')) {
return false;
}
if (empty($this->modulus) || empty($this->publicExponent)) {
return false;
}
$oldFormat = $this->publicKeyFormat;
$this->publicKeyFormat = $type;
$temp = $type::savePublicKey($this->modulus, $this->publicExponent);
$this->publicKeyFormat = $oldFormat;
return $temp;
}
/**
* Returns the public key's fingerprint
*
* The public key's fingerprint is returned, which is equivalent to running `ssh-keygen -lf rsa.pub`. If there is
* no public key currently loaded, false is returned.
* Example output (md5): "c1:b1:30:29:d7:b8:de:6c:97:77:10:d7:46:41:63:87" (as specified by RFC 4716)
*
* @access public
* @param string $algorithm The hashing algorithm to be used. Valid options are 'md5' and 'sha256'. False is returned
* for invalid values.
* @return mixed
*/
function getPublicKeyFingerprint($algorithm = 'md5')
{
if (empty($this->modulus) || empty($this->publicExponent)) {
return false;
}
$modulus = $this->modulus->toBytes(true);
$publicExponent = $this->publicExponent->toBytes(true);
$RSAPublicKey = pack('Na*Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($publicExponent), $publicExponent, strlen($modulus), $modulus);
switch ($algorithm) {
case 'sha256':
$hash = new Hash('sha256');
$base = Base64::encode($hash->hash($RSAPublicKey));
return substr($base, 0, strlen($base) - 1);
case 'md5':
return substr(chunk_split(md5($RSAPublicKey), 2, ':'), 0, -1);
default:
return false;
}
}
/**
* 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 self::getPrivateKey()
* @access private
* @param string $type optional
* @return mixed
*/
function _getPrivatePublicKey($type = 'PKCS8')
{
$type = strtolower($type);
if (!isset(self::$fileFormats[$type])) {
return false;
}
$type = self::$fileFormats[$type];
if (!method_exists($type, 'savePublicKey')) {
return false;
}
if (empty($this->modulus) || empty($this->exponent)) {
return false;
}
$oldFormat = $this->publicKeyFormat;
$this->publicKeyFormat = $type;
$temp = $type::savePublicKey($this->modulus, $this->exponent);
$this->publicKeyFormat = $oldFormat;
return $temp;
}
/**
* __toString() magic method
*
* @access public
* @return string
*/
function __toString()
{
$key = $this->getPrivateKey($this->privateKeyFormat);
if (is_string($key)) {
return $key;
}
$key = $this->_getPrivatePublicKey($this->publicKeyFormat);
return is_string($key) ? $key : '';
}
/**
* __clone() magic method
*
* @access public
* @return \phpseclib\Crypt\RSA
*/
function __clone()
{
$key = new RSA();
$key->load($this);
return $key;
}
/**
* Generates the smallest and largest numbers requiring $bits bits
*
* @access private
* @param int $bits
* @return array
*/
static function _generateMinMax($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 {
$min[0] = chr(0x80);
}
return array(
'min' => new BigInteger($min, 256),
'max' => new 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 paragraph 8.1.3} for more information.
*
* @access private
* @param string $string
* @return int
*/
function _decodeLength(&$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 paragraph 8.1.3} for more information.
*
* @access private
* @param int $length
* @return string
*/
function _encodeLength($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 int $index
* @return string
* @access private
*/
function _string_shift(&$string, $index = 1)
{
$substr = substr($string, 0, $index);
$string = substr($string, $index);
return $substr;
}
/**
* Determines the private key format
*
* @see self::createKey()
* @access public
* @param int $format
*/
function setPrivateKeyFormat($format)
{
$this->privateKeyFormat = $format;
}
/**
* Determines the public key format
*
* @see self::createKey()
* @access public
* @param int $format
*/
function setPublicKeyFormat($format)
{
$this->publicKeyFormat = $format;
}
/**
* Determines which hashing function should be used
*
* Used with signature production / verification and (if the encryption mode is self::PADDING_OAEP) encryption and
* decryption. If $hash isn't supported, sha256 is used.
*
* @access public
* @param string $hash
*/
function setHash($hash)
{
// \phpseclib\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':
case 'sha224':
case 'sha512/224':
case 'sha512/256':
$this->hash = new Hash($hash);
$this->hashName = $hash;
break;
default:
$this->hash = new Hash('sha256');
$this->hashName = 'sha256';
}
$this->hLen = $this->hash->getLength();
}
/**
* Determines which hashing function should be used for the mask generation function
*
* The mask generation function is used by self::PADDING_OAEP and self::PADDING_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)
{
// \phpseclib\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':
case 'sha224':
case 'sha512/224':
case 'sha512/256':
$this->mgfHash = new Hash($hash);
break;
default:
$this->mgfHash = new Hash('sha256');
}
$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 int $format
*/
function setSaltLength($sLen)
{
$this->sLen = $sLen;
}
/**
* Integer-to-Octet-String primitive
*
* See {@link http://tools.ietf.org/html/rfc3447#section-4.1 RFC3447#section-4.1}.
*
* @access private
* @param bool|\phpseclib\Math\BigInteger $x
* @param int $xLen
* @return bool|string
*/
function _i2osp($x, $xLen)
{
if ($x === false) {
return false;
}
$x = $x->toBytes();
if (strlen($x) > $xLen) {
return false;
}
return str_pad($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 $x
* @return \phpseclib\Math\BigInteger
*/
function _os2ip($x)
{
return new 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 \phpseclib\Math\BigInteger $x
* @return \phpseclib\Math\BigInteger
*/
function _exponentiate($x)
{
switch (true) {
case empty($this->primes):
case $this->primes[1]->equals(self::$zero):
case empty($this->coefficients):
case $this->coefficients[2]->equals(self::$zero):
case empty($this->exponents):
case $this->exponents[1]->equals(self::$zero):
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];
}
}
$r = BigInteger::random(self::$one, $smallest->subtract(self::$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 \phpseclib\Math\BigInteger $x
* @param \phpseclib\Math\BigInteger $r
* @param int $i
* @return \phpseclib\Math\BigInteger
*/
function _blind($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't use MessageDigest.isEquals)}
*
* Thanks for the heads up singpolyma!
*
* @access private
* @param string $x
* @param string $y
* @return bool
*/
function _equals($x, $y)
{
if (strlen($x) != strlen($y)) {
return false;
}
$result = 0;
for ($i = 0; $i < strlen($x); $i++) {
$result |= ord($x[$i]) ^ ord($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 \phpseclib\Math\BigInteger $m
* @return bool|\phpseclib\Math\BigInteger
*/
function _rsaep($m)
{
if ($m->compare(self::$zero) < 0 || $m->compare($this->modulus) > 0) {
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 \phpseclib\Math\BigInteger $c
* @return bool|\phpseclib\Math\BigInteger
*/
function _rsadp($c)
{
if ($c->compare(self::$zero) < 0 || $c->compare($this->modulus) > 0) {
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 \phpseclib\Math\BigInteger $m
* @return bool|\phpseclib\Math\BigInteger
*/
function _rsasp1($m)
{
if ($m->compare(self::$zero) < 0 || $m->compare($this->modulus) > 0) {
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 \phpseclib\Math\BigInteger $s
* @return bool|\phpseclib\Math\BigInteger
*/
function _rsavp1($s)
{
if ($s->compare(self::$zero) < 0 || $s->compare($this->modulus) > 0) {
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 int $mgfLen
* @return string
*/
function _mgf1($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 $l
* @throws \OutOfBoundsException if strlen($m) > $this->k - 2 * $this->hLen - 2
* @return string
*/
function _rsaes_oaep_encrypt($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) {
throw new \OutOfBoundsException('Message too long');
}
// 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;
$seed = Random::string($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 $l
* @return bool|string
*/
function _rsaes_oaep_decrypt($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) {
return false;
}
// RSA decryption
$c = $this->_os2ip($c);
$m = $this->_rsadp($c);
$em = $this->_i2osp($m, $this->k);
if ($em === false) {
return false;
}
// 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) {
return false;
}
$m = ltrim($m, chr(0));
if (ord($m[0]) != 1) {
return false;
}
// Output the message M
return substr($m, 1);
}
/**
* Raw Encryption / Decryption
*
* Doesn't use padding and is not recommended.
*
* @access private
* @param string $m
* @return bool|string
* @throws \OutOfBoundsException if strlen($m) > $this->k
*/
function _raw_encrypt($m)
{
if (strlen($m) > $this->k) {
throw new \OutOfBoundsException('Message too long');
}
$temp = $this->_os2ip($m);
$temp = $this->_rsaep($temp);
return $this->_i2osp($temp, $this->k);
}
/**
* 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
* @param bool $pkcs15_compat optional
* @throws \OutOfBoundsException if strlen($m) > $this->k - 11
* @return bool|string
*/
function _rsaes_pkcs1_v1_5_encrypt($m, $pkcs15_compat = false)
{
$mLen = strlen($m);
// Length checking
if ($mLen > $this->k - 11) {
throw new \OutOfBoundsException('Message too long');
}
// EME-PKCS1-v1_5 encoding
$psLen = $this->k - $mLen - 3;
$ps = '';
while (strlen($ps) != $psLen) {
$temp = Random::string($psLen - strlen($ps));
$temp = str_replace("\x00", '', $temp);
$ps.= $temp;
}
$type = 2;
// see the comments of _rsaes_pkcs1_v1_5_decrypt() to understand why this is being done
if ($pkcs15_compat && (!isset($this->publicExponent) || $this->exponent !== $this->publicExponent)) {
$type = 1;
// "The padding string PS shall consist of k-3-||D|| octets. ... for block type 01, they shall have value FF"
$ps = str_repeat("\xFF", $psLen);
}
$em = chr(0) . chr($type) . $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 compatibility 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 compatibility 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 \phpseclib\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 $c
* @return bool|string
*/
function _rsaes_pkcs1_v1_5_decrypt($c)
{
// Length checking
if (strlen($c) != $this->k) { // or if k < 11
return false;
}
// RSA decryption
$c = $this->_os2ip($c);
$m = $this->_rsadp($c);
$em = $this->_i2osp($m, $this->k);
if ($em === false) {
return false;
}
// EME-PKCS1-v1_5 decoding
if (ord($em[0]) != 0 || ord($em[1]) > 2) {
return false;
}
$ps = substr($em, 2, strpos($em, chr(0), 2) - 2);
$m = substr($em, strlen($ps) + 3);
if (strlen($ps) < 8) {
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
* @throws \RuntimeException on encoding error
* @param int $emBits
*/
function _emsa_pss_encode($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 ? $this->sLen : $this->hLen;
$mHash = $this->hash->hash($m);
if ($emLen < $this->hLen + $sLen + 2) {
return false;
}
$salt = Random::string($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 int $emBits
* @return string
*/
function _emsa_pss_verify($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 ? $this->sLen : $this->hLen;
$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 $m
* @return bool|string
*/
function _rsassa_pss_sign($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 $s
* @return bool|string
*/
function _rsassa_pss_verify($m, $s)
{
// Length checking
if (strlen($s) != $this->k) {
return false;
}
// RSA verification
$modBits = 8 * $this->k;
$s2 = $this->_os2ip($s);
$m2 = $this->_rsavp1($s2);
$em = $this->_i2osp($m2, $modBits >> 3);
if ($em === false) {
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 int $emLen
* @throws \LengthException if the intended encoded message length is too short
* @return string
*/
function _emsa_pkcs1_v1_5_encode($m, $emLen)
{
$h = $this->hash->hash($m);
// see http://tools.ietf.org/html/rfc3447#page-43
switch ($this->hashName) {
case 'md2':
$t = "\x30\x20\x30\x0c\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x02\x05\x00\x04\x10";
break;
case 'md5':
$t = "\x30\x20\x30\x0c\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05\x05\x00\x04\x10";
break;
case 'sha1':
$t = "\x30\x21\x30\x09\x06\x05\x2b\x0e\x03\x02\x1a\x05\x00\x04\x14";
break;
case 'sha256':
$t = "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01\x05\x00\x04\x20";
break;
case 'sha384':
$t = "\x30\x41\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02\x05\x00\x04\x30";
break;
case 'sha512':
$t = "\x30\x51\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03\x05\x00\x04\x40";
break;
// from https://www.emc.com/collateral/white-papers/h11300-pkcs-1v2-2-rsa-cryptography-standard-wp.pdf#page=40
case 'sha224':
$t = "\x30\x2d\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x04\x05\x00\x04\x1c";
break;
case 'sha512/224':
$t = "\x30\x2d\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x05\x05\x00\x04\x1c";
break;
case 'sha512/256':
$t = "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x06\x05\x00\x04\x20";
}
$t.= $h;
$tLen = strlen($t);
if ($emLen < $tLen + 11) {
throw new \LengthException('Intended encoded message length too short');
}
$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 $m
* @throws \LengthException if the RSA modulus is too short
* @return bool|string
*/
function _rsassa_pkcs1_v1_5_sign($m)
{
// EMSA-PKCS1-v1_5 encoding
// If the encoding operation outputs "intended encoded message length too short," output "RSA modulus
// too short" and stop.
try {
$em = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
} catch (\LengthException $e) {
throw new \LengthException('RSA modulus too short');
}
// 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
* @param string $s
* @throws \LengthException if the RSA modulus is too short
* @return bool
*/
function _rsassa_pkcs1_v1_5_verify($m, $s)
{
// Length checking
if (strlen($s) != $this->k) {
return false;
}
// RSA verification
$s = $this->_os2ip($s);
$m2 = $this->_rsavp1($s);
$em = $this->_i2osp($m2, $this->k);
if ($em === false) {
return false;
}
// EMSA-PKCS1-v1_5 encoding
// If the encoding operation outputs "intended encoded message length too short," output "RSA modulus
// too short" and stop.
try {
$em2 = $this->_emsa_pkcs1_v1_5_encode($m, $this->k);
} catch (\LengthException $e) {
throw new \LengthException('RSA modulus too short');
}
// Compare
return $this->_equals($em, $em2);
}
/**
* RSASSA-PKCS1-V1_5-VERIFY (relaxed matching)
*
* Per {@link http://tools.ietf.org/html/rfc3447#page-43 RFC3447#page-43} PKCS1 v1.5
* specified the use BER encoding rather than DER encoding that PKCS1 v2.0 specified.
* This means that under rare conditions you can have a perfectly valid v1.5 signature
* that fails to validate with _rsassa_pkcs1_v1_5_verify(). PKCS1 v2.1 also recommends
* that if you're going to validate these types of signatures you "should indicate
* whether the underlying BER encoding is a DER encoding and hence whether the signature
* is valid with respect to the specification given in [PKCS1 v2.0+]". so if you do
* $rsa->getLastPadding() and get RSA::PADDING_RELAXED_PKCS1 back instead of
* RSA::PADDING_PKCS1... that means BER encoding was used.
*
* @access private
* @param string $m
* @param string $s
* @return bool
*/
function _rsassa_pkcs1_v1_5_relaxed_verify($m, $s)
{
// Length checking
if (strlen($s) != $this->k) {
return false;
}
// RSA verification
$s = $this->_os2ip($s);
$m2 = $this->_rsavp1($s);
if ($m2 === false) {
return false;
}
$em = $this->_i2osp($m2, $this->k);
if ($em === false) {
return false;
}
if ($this->_string_shift($em, 2) != "\0\1") {
return false;
}
$em = ltrim($em, "\xFF");
if ($this->_string_shift($em) != "\0") {
return false;
}
$asn1 = new ASN1();
$decoded = $asn1->decodeBER($em);
if (!is_array($decoded) || empty($decoded[0]) || strlen($em) > $decoded[0]['length']) {
return false;
}
$AlgorithmIdentifier = array(
'type' => ASN1::TYPE_SEQUENCE,
'children' => array(
'algorithm' => array('type' => ASN1::TYPE_OBJECT_IDENTIFIER),
'parameters' => array(
'type' => ASN1::TYPE_ANY,
'optional' => true
)
)
);
$DigestInfo = array(
'type' => ASN1::TYPE_SEQUENCE,
'children' => array(
'digestAlgorithm' => $AlgorithmIdentifier,
'digest' => array('type' => ASN1::TYPE_OCTET_STRING)
)
);
$oids = array(
'1.2.840.113549.2.2' => 'md2',
'1.2.840.113549.2.4' => 'md4', // from PKCS1 v1.5
'1.2.840.113549.2.5' => 'md5',
'1.3.14.3.2.26' => 'sha1',
'2.16.840.1.101.3.4.2.1' => 'sha256',
'2.16.840.1.101.3.4.2.2' => 'sha384',
'2.16.840.1.101.3.4.2.3' => 'sha512',
// from PKCS1 v2.2
'2.16.840.1.101.3.4.2.4' => 'sha224',
'2.16.840.1.101.3.4.2.5' => 'sha512/224',
'2.16.840.1.101.3.4.2.6' => 'sha512/256',
);
$asn1->loadOIDs($oids);
$decoded = $asn1->asn1map($decoded[0], $DigestInfo);
if (!isset($decoded) || $decoded === false) {
return false;
}
if (!in_array($decoded['digestAlgorithm']['algorithm'], $oids)) {
return false;
}
$hash = new Hash($decoded['digestAlgorithm']['algorithm']);
$em = $hash->hash($m);
$em2 = Base64::decode($decoded['digest']);
return $this->_equals($em, $em2);
}
/**
* Encryption
*
* Both self::PADDING_OAEP and self::PADDING_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 self::decrypt()
* @access public
* @param string $plaintext
* @param int $padding optional
* @return bool|string
* @throws \LengthException if the RSA modulus is too short
*/
function encrypt($plaintext, $padding = self::PADDING_OAEP)
{
switch ($padding) {
case self::PADDING_NONE:
return $this->_raw_encrypt($plaintext);
case self::PADDING_PKCS15_COMPAT:
case self::PADDING_PKCS1:
return $this->_rsaes_pkcs1_v1_5_encrypt($plaintext, $padding == self::PADDING_PKCS15_COMPAT);
//case self::PADDING_OAEP:
default:
return $this->_rsaes_oaep_encrypt($plaintext);
}
}
/**
* Decryption
*
* @see self::encrypt()
* @access public
* @param string $plaintext
* @param int $padding optional
* @return bool|string
*/
function decrypt($ciphertext, $padding = self::PADDING_OAEP)
{
switch ($padding) {
case self::PADDING_NONE:
return $this->_raw_encrypt($ciphertext);
case self::PADDING_PKCS1:
return $this->_rsaes_pkcs1_v1_5_decrypt($ciphertext);
//case self::PADDING_OAEP:
default:
return $this->_rsaes_oaep_decrypt($ciphertext);
}
}
/**
* Create a signature
*
* @see self::verify()
* @access public
* @param string $message
* @param int $padding optional
* @return string
*/
function sign($message, $padding = self::PADDING_PSS)
{
if (empty($this->modulus) || empty($this->exponent)) {
return false;
}
switch ($padding) {
case self::PADDING_PKCS1:
case self::PADDING_RELAXED_PKCS1:
return $this->_rsassa_pkcs1_v1_5_sign($message);
//case self::PADDING_PSS:
default:
return $this->_rsassa_pss_sign($message);
}
}
/**
* Verifies a signature
*
* @see self::sign()
* @access public
* @param string $message
* @param string $signature
* @param int $padding optional
* @return bool
*/
function verify($message, $signature, $padding = self::PADDING_PSS)
{
if (empty($this->modulus) || empty($this->exponent)) {
return false;
}
switch ($padding) {
case self::PADDING_RELAXED_PKCS1:
return $this->_rsassa_pkcs1_v1_5_relaxed_verify($message, $signature);
case self::PADDING_PKCS1:
return $this->_rsassa_pkcs1_v1_5_verify($message, $signature);
//case self::PADDING_PSS:
default:
return $this->_rsassa_pss_verify($message, $signature);
}
}
}