diff options
Diffstat (limited to 'Crypt/RSA/Math')
-rw-r--r-- | Crypt/RSA/Math/BCMath.php | 482 | ||||
-rw-r--r-- | Crypt/RSA/Math/BigInt.php | 313 | ||||
-rw-r--r-- | Crypt/RSA/Math/GMP.php | 361 |
3 files changed, 1156 insertions, 0 deletions
diff --git a/Crypt/RSA/Math/BCMath.php b/Crypt/RSA/Math/BCMath.php new file mode 100644 index 000000000..646ff6710 --- /dev/null +++ b/Crypt/RSA/Math/BCMath.php @@ -0,0 +1,482 @@ +<?php +/** + * Crypt_RSA allows to do following operations: + * - key pair generation + * - encryption and decryption + * - signing and sign validation + * + * PHP versions 4 and 5 + * + * LICENSE: This source file is subject to version 3.0 of the PHP license + * that is available through the world-wide-web at the following URI: + * http://www.php.net/license/3_0.txt. If you did not receive a copy of + * the PHP License and are unable to obtain it through the web, please + * send a note to license@php.net so we can mail you a copy immediately. + * + * @category Encryption + * @package Crypt_RSA + * @author Alexander Valyalkin <valyala@gmail.com> + * @copyright 2006 Alexander Valyalkin + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @version 1.2.0b + * @link http://pear.php.net/package/Crypt_RSA + */ + +/** + * Crypt_RSA_Math_BCMath class. + * + * Provides set of math functions, which are used by Crypt_RSA package + * This class is a wrapper for PHP BCMath extension. + * See http://php.net/manual/en/ref.bc.php for details. + * + * @category Encryption + * @package Crypt_RSA + * @author Alexander Valyalkin <valyala@gmail.com> + * @copyright 2005, 2006 Alexander Valyalkin + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @link http://pear.php.net/package/Crypt_RSA + * @version @package_version@ + * @access public + */ +class Crypt_RSA_Math_BCMath +{ + /** + * error description + * + * @var string + * @access public + */ + var $errstr = ''; + + /** + * Performs Miller-Rabin primality test for number $num + * with base $base. Returns true, if $num is strong pseudoprime + * by base $base. Else returns false. + * + * @param string $num + * @param string $base + * @return bool + * @access private + */ + function _millerTest($num, $base) + { + if (!bccomp($num, '1')) { + // 1 is not prime ;) + return false; + } + $tmp = bcsub($num, '1'); + + $zero_bits = 0; + while (!bccomp(bcmod($tmp, '2'), '0')) { + $zero_bits++; + $tmp = bcdiv($tmp, '2'); + } + + $tmp = $this->powmod($base, $tmp, $num); + if (!bccomp($tmp, '1')) { + // $num is probably prime + return true; + } + + while ($zero_bits--) { + if (!bccomp(bcadd($tmp, '1'), $num)) { + // $num is probably prime + return true; + } + $tmp = $this->powmod($tmp, '2', $num); + } + // $num is composite + return false; + } + + /** + * Crypt_RSA_Math_BCMath constructor. + * Checks an existance of PHP BCMath extension. + * On failure saves error description in $this->errstr + * + * @access public + */ + function Crypt_RSA_Math_BCMath() + { + if (!extension_loaded('bcmath')) { + if (!@dl('bcmath.' . PHP_SHLIB_SUFFIX) && !@dl('php_bcmath.' . PHP_SHLIB_SUFFIX)) { + // cannot load BCMath extension. Set error string + $this->errstr = 'Crypt_RSA package requires the BCMath extension. See http://php.net/manual/en/ref.bc.php for details'; + return; + } + } + } + + /** + * Transforms binary representation of large integer into its native form. + * + * Example of transformation: + * $str = "\x12\x34\x56\x78\x90"; + * $num = 0x9078563412; + * + * @param string $str + * @return string + * @access public + */ + function bin2int($str) + { + $result = '0'; + $n = strlen($str); + do { + $result = bcadd(bcmul($result, '256'), ord($str{--$n})); + } while ($n > 0); + return $result; + } + + /** + * Transforms large integer into binary representation. + * + * Example of transformation: + * $num = 0x9078563412; + * $str = "\x12\x34\x56\x78\x90"; + * + * @param string $num + * @return string + * @access public + */ + function int2bin($num) + { + $result = ''; + do { + $result .= chr(bcmod($num, '256')); + $num = bcdiv($num, '256'); + } while (bccomp($num, '0')); + return $result; + } + + /** + * Calculates pow($num, $pow) (mod $mod) + * + * @param string $num + * @param string $pow + * @param string $mod + * @return string + * @access public + */ + function powmod($num, $pow, $mod) + { + if (function_exists('bcpowmod')) { + // bcpowmod is only available under PHP5 + return bcpowmod($num, $pow, $mod); + } + + // emulate bcpowmod + $result = '1'; + do { + if (!bccomp(bcmod($pow, '2'), '1')) { + $result = bcmod(bcmul($result, $num), $mod); + } + $num = bcmod(bcpow($num, '2'), $mod); + $pow = bcdiv($pow, '2'); + } while (bccomp($pow, '0')); + return $result; + } + + /** + * Calculates $num1 * $num2 + * + * @param string $num1 + * @param string $num2 + * @return string + * @access public + */ + function mul($num1, $num2) + { + return bcmul($num1, $num2); + } + + /** + * Calculates $num1 % $num2 + * + * @param string $num1 + * @param string $num2 + * @return string + * @access public + */ + function mod($num1, $num2) + { + return bcmod($num1, $num2); + } + + /** + * Compares abs($num1) to abs($num2). + * Returns: + * -1, if abs($num1) < abs($num2) + * 0, if abs($num1) == abs($num2) + * 1, if abs($num1) > abs($num2) + * + * @param string $num1 + * @param string $num2 + * @return int + * @access public + */ + function cmpAbs($num1, $num2) + { + return bccomp($num1, $num2); + } + + /** + * Tests $num on primality. Returns true, if $num is strong pseudoprime. + * Else returns false. + * + * @param string $num + * @return bool + * @access private + */ + function isPrime($num) + { + static $primes = null; + static $primes_cnt = 0; + if (is_null($primes)) { + // generate all primes up to 10000 + $primes = array(); + for ($i = 0; $i < 10000; $i++) { + $primes[] = $i; + } + $primes[0] = $primes[1] = 0; + for ($i = 2; $i < 100; $i++) { + while (!$primes[$i]) { + $i++; + } + $j = $i; + for ($j += $i; $j < 10000; $j += $i) { + $primes[$j] = 0; + } + } + $j = 0; + for ($i = 0; $i < 10000; $i++) { + if ($primes[$i]) { + $primes[$j++] = $primes[$i]; + } + } + $primes_cnt = $j; + } + + // try to divide number by small primes + for ($i = 0; $i < $primes_cnt; $i++) { + if (bccomp($num, $primes[$i]) <= 0) { + // number is prime + return true; + } + if (!bccomp(bcmod($num, $primes[$i]), '0')) { + // number divides by $primes[$i] + return false; + } + } + + /* + try Miller-Rabin's probable-primality test for first + 7 primes as bases + */ + for ($i = 0; $i < 7; $i++) { + if (!$this->_millerTest($num, $primes[$i])) { + // $num is composite + return false; + } + } + // $num is strong pseudoprime + return true; + } + + /** + * Generates prime number with length $bits_cnt + * using $random_generator as random generator function. + * + * @param int $bits_cnt + * @param string $rnd_generator + * @access public + */ + function getPrime($bits_cnt, $random_generator) + { + $bytes_n = intval($bits_cnt / 8); + $bits_n = $bits_cnt % 8; + do { + $str = ''; + for ($i = 0; $i < $bytes_n; $i++) { + $str .= chr(call_user_func($random_generator) & 0xff); + } + $n = call_user_func($random_generator) & 0xff; + $n |= 0x80; + $n >>= 8 - $bits_n; + $str .= chr($n); + $num = $this->bin2int($str); + + // search for the next closest prime number after [$num] + if (!bccomp(bcmod($num, '2'), '0')) { + $num = bcadd($num, '1'); + } + while (!$this->isPrime($num)) { + $num = bcadd($num, '2'); + } + } while ($this->bitLen($num) != $bits_cnt); + return $num; + } + + /** + * Calculates $num - 1 + * + * @param string $num + * @return string + * @access public + */ + function dec($num) + { + return bcsub($num, '1'); + } + + /** + * Returns true, if $num is equal to one. Else returns false + * + * @param string $num + * @return bool + * @access public + */ + function isOne($num) + { + return !bccomp($num, '1'); + } + + /** + * Finds greatest common divider (GCD) of $num1 and $num2 + * + * @param string $num1 + * @param string $num2 + * @return string + * @access public + */ + function GCD($num1, $num2) + { + do { + $tmp = bcmod($num1, $num2); + $num1 = $num2; + $num2 = $tmp; + } while (bccomp($num2, '0')); + return $num1; + } + + /** + * Finds inverse number $inv for $num by modulus $mod, such as: + * $inv * $num = 1 (mod $mod) + * + * @param string $num + * @param string $mod + * @return string + * @access public + */ + function invmod($num, $mod) + { + $x = '1'; + $y = '0'; + $num1 = $mod; + do { + $tmp = bcmod($num, $num1); + $q = bcdiv($num, $num1); + $num = $num1; + $num1 = $tmp; + + $tmp = bcsub($x, bcmul($y, $q)); + $x = $y; + $y = $tmp; + } while (bccomp($num1, '0')); + if (bccomp($x, '0') < 0) { + $x = bcadd($x, $mod); + } + return $x; + } + + /** + * Returns bit length of number $num + * + * @param string $num + * @return int + * @access public + */ + function bitLen($num) + { + $tmp = $this->int2bin($num); + $bit_len = strlen($tmp) * 8; + $tmp = ord($tmp{strlen($tmp) - 1}); + if (!$tmp) { + $bit_len -= 8; + } + else { + while (!($tmp & 0x80)) { + $bit_len--; + $tmp <<= 1; + } + } + return $bit_len; + } + + /** + * Calculates bitwise or of $num1 and $num2, + * starting from bit $start_pos for number $num1 + * + * @param string $num1 + * @param string $num2 + * @param int $start_pos + * @return string + * @access public + */ + function bitOr($num1, $num2, $start_pos) + { + $start_byte = intval($start_pos / 8); + $start_bit = $start_pos % 8; + $tmp1 = $this->int2bin($num1); + + $num2 = bcmul($num2, 1 << $start_bit); + $tmp2 = $this->int2bin($num2); + if ($start_byte < strlen($tmp1)) { + $tmp2 |= substr($tmp1, $start_byte); + $tmp1 = substr($tmp1, 0, $start_byte) . $tmp2; + } + else { + $tmp1 = str_pad($tmp1, $start_byte, "\0") . $tmp2; + } + return $this->bin2int($tmp1); + } + + /** + * Returns part of number $num, starting at bit + * position $start with length $length + * + * @param string $num + * @param int start + * @param int length + * @return string + * @access public + */ + function subint($num, $start, $length) + { + $start_byte = intval($start / 8); + $start_bit = $start % 8; + $byte_length = intval($length / 8); + $bit_length = $length % 8; + if ($bit_length) { + $byte_length++; + } + $num = bcdiv($num, 1 << $start_bit); + $tmp = substr($this->int2bin($num), $start_byte, $byte_length); + $tmp = str_pad($tmp, $byte_length, "\0"); + $tmp = substr_replace($tmp, $tmp{$byte_length - 1} & chr(0xff >> (8 - $bit_length)), $byte_length - 1, 1); + return $this->bin2int($tmp); + } + + /** + * Returns name of current wrapper + * + * @return string name of current wrapper + * @access public + */ + function getWrapperName() + { + return 'BCMath'; + } +} + +?>
\ No newline at end of file diff --git a/Crypt/RSA/Math/BigInt.php b/Crypt/RSA/Math/BigInt.php new file mode 100644 index 000000000..b7ac24cb6 --- /dev/null +++ b/Crypt/RSA/Math/BigInt.php @@ -0,0 +1,313 @@ +<?php +/** + * Crypt_RSA allows to do following operations: + * - key pair generation + * - encryption and decryption + * - signing and sign validation + * + * PHP versions 4 and 5 + * + * LICENSE: This source file is subject to version 3.0 of the PHP license + * that is available through the world-wide-web at the following URI: + * http://www.php.net/license/3_0.txt. If you did not receive a copy of + * the PHP License and are unable to obtain it through the web, please + * send a note to license@php.net so we can mail you a copy immediately. + * + * @category Encryption + * @package Crypt_RSA + * @author Alexander Valyalkin <valyala@gmail.com> + * @copyright 2005, 2006 Alexander Valyalkin + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @version 1.2.0b + * @link http://pear.php.net/package/Crypt_RSA + */ + +/** + * Crypt_RSA_Math_BigInt class. + * + * Provides set of math functions, which are used by Crypt_RSA package + * This class is a wrapper for big_int PECL extension, + * which could be loaded from http://pecl.php.net/packages/big_int + * + * @category Encryption + * @package Crypt_RSA + * @author Alexander Valyalkin <valyala@gmail.com> + * @copyright 2005, 2006 Alexander Valyalkin + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @link http://pear.php.net/package/Crypt_RSA + * @version @package_version@ + * @access public + */ +class Crypt_RSA_Math_BigInt +{ + /** + * error description + * + * @var string + * @access public + */ + var $errstr = ''; + + /** + * Crypt_RSA_Math_BigInt constructor. + * Checks an existance of big_int PECL math package. + * This package is available at http://pecl.php.net/packages/big_int + * On failure saves error description in $this->errstr + * + * @access public + */ + function Crypt_RSA_Math_BigInt() + { + if (!extension_loaded('big_int')) { + if (!@dl('big_int.' . PHP_SHLIB_SUFFIX) && !@dl('php_big_int.' . PHP_SHLIB_SUFFIX)) { + // cannot load big_int extension + $this->errstr = 'Crypt_RSA package requires big_int PECL package. ' . + 'It is available at http://pecl.php.net/packages/big_int'; + return; + } + } + + // check version of big_int extension ( Crypt_RSA requires version 1.0.2 and higher ) + if (!in_array('bi_info', get_extension_funcs('big_int'))) { + // there is no bi_info() function in versions, older than 1.0.2 + $this->errstr = 'Crypt_RSA package requires big_int package version 1.0.2 and higher'; + } + } + + /** + * Transforms binary representation of large integer into its native form. + * + * Example of transformation: + * $str = "\x12\x34\x56\x78\x90"; + * $num = 0x9078563412; + * + * @param string $str + * @return big_int resource + * @access public + */ + function bin2int($str) + { + return bi_unserialize($str); + } + + /** + * Transforms large integer into binary representation. + * + * Example of transformation: + * $num = 0x9078563412; + * $str = "\x12\x34\x56\x78\x90"; + * + * @param big_int resource $num + * @return string + * @access public + */ + function int2bin($num) + { + return bi_serialize($num); + } + + /** + * Calculates pow($num, $pow) (mod $mod) + * + * @param big_int resource $num + * @param big_int resource $pow + * @param big_int resource $mod + * @return big_int resource + * @access public + */ + function powmod($num, $pow, $mod) + { + return bi_powmod($num, $pow, $mod); + } + + /** + * Calculates $num1 * $num2 + * + * @param big_int resource $num1 + * @param big_int resource $num2 + * @return big_int resource + * @access public + */ + function mul($num1, $num2) + { + return bi_mul($num1, $num2); + } + + /** + * Calculates $num1 % $num2 + * + * @param string $num1 + * @param string $num2 + * @return string + * @access public + */ + function mod($num1, $num2) + { + return bi_mod($num1, $num2); + } + + /** + * Compares abs($num1) to abs($num2). + * Returns: + * -1, if abs($num1) < abs($num2) + * 0, if abs($num1) == abs($num2) + * 1, if abs($num1) > abs($num2) + * + * @param big_int resource $num1 + * @param big_int resource $num2 + * @return int + * @access public + */ + function cmpAbs($num1, $num2) + { + return bi_cmp_abs($num1, $num2); + } + + /** + * Tests $num on primality. Returns true, if $num is strong pseudoprime. + * Else returns false. + * + * @param string $num + * @return bool + * @access private + */ + function isPrime($num) + { + return bi_is_prime($num) ? true : false; + } + + /** + * Generates prime number with length $bits_cnt + * using $random_generator as random generator function. + * + * @param int $bits_cnt + * @param string $rnd_generator + * @access public + */ + function getPrime($bits_cnt, $random_generator) + { + $bytes_n = intval($bits_cnt / 8); + $bits_n = $bits_cnt % 8; + do { + $str = ''; + for ($i = 0; $i < $bytes_n; $i++) { + $str .= chr(call_user_func($random_generator) & 0xff); + } + $n = call_user_func($random_generator) & 0xff; + $n |= 0x80; + $n >>= 8 - $bits_n; + $str .= chr($n); + $num = $this->bin2int($str); + + // search for the next closest prime number after [$num] + $num = bi_next_prime($num); + } while ($this->bitLen($num) != $bits_cnt); + return $num; + } + + /** + * Calculates $num - 1 + * + * @param big_int resource $num + * @return big_int resource + * @access public + */ + function dec($num) + { + return bi_dec($num); + } + + /** + * Returns true, if $num is equal to 1. Else returns false + * + * @param big_int resource $num + * @return bool + * @access public + */ + function isOne($num) + { + return bi_is_one($num); + } + + /** + * Finds greatest common divider (GCD) of $num1 and $num2 + * + * @param big_int resource $num1 + * @param big_int resource $num2 + * @return big_int resource + * @access public + */ + function GCD($num1, $num2) + { + return bi_gcd($num1, $num2); + } + + /** + * Finds inverse number $inv for $num by modulus $mod, such as: + * $inv * $num = 1 (mod $mod) + * + * @param big_int resource $num + * @param big_int resource $mod + * @return big_int resource + * @access public + */ + function invmod($num, $mod) + { + return bi_invmod($num, $mod); + } + + /** + * Returns bit length of number $num + * + * @param big_int resource $num + * @return int + * @access public + */ + function bitLen($num) + { + return bi_bit_len($num); + } + + /** + * Calculates bitwise or of $num1 and $num2, + * starting from bit $start_pos for number $num1 + * + * @param big_int resource $num1 + * @param big_int resource $num2 + * @param int $start_pos + * @return big_int resource + * @access public + */ + function bitOr($num1, $num2, $start_pos) + { + return bi_or($num1, $num2, $start_pos); + } + + /** + * Returns part of number $num, starting at bit + * position $start with length $length + * + * @param big_int resource $num + * @param int start + * @param int length + * @return big_int resource + * @access public + */ + function subint($num, $start, $length) + { + return bi_subint($num, $start, $length); + } + + /** + * Returns name of current wrapper + * + * @return string name of current wrapper + * @access public + */ + function getWrapperName() + { + return 'BigInt'; + } +} + +?>
\ No newline at end of file diff --git a/Crypt/RSA/Math/GMP.php b/Crypt/RSA/Math/GMP.php new file mode 100644 index 000000000..54e4c34fc --- /dev/null +++ b/Crypt/RSA/Math/GMP.php @@ -0,0 +1,361 @@ +<?php +/** + * Crypt_RSA allows to do following operations: + * - key pair generation + * - encryption and decryption + * - signing and sign validation + * + * PHP versions 4 and 5 + * + * LICENSE: This source file is subject to version 3.0 of the PHP license + * that is available through the world-wide-web at the following URI: + * http://www.php.net/license/3_0.txt. If you did not receive a copy of + * the PHP License and are unable to obtain it through the web, please + * send a note to license@php.net so we can mail you a copy immediately. + * + * @category Encryption + * @package Crypt_RSA + * @author Alexander Valyalkin <valyala@gmail.com> + * @copyright 2005, 2006 Alexander Valyalkin + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @version 1.2.0b + * @link http://pear.php.net/package/Crypt_RSA + */ + +/** + * Crypt_RSA_Math_GMP class. + * + * Provides set of math functions, which are used by Crypt_RSA package + * This class is a wrapper for PHP GMP extension. + * See http://php.net/gmp for details. + * + * @category Encryption + * @package Crypt_RSA + * @author Alexander Valyalkin <valyala@gmail.com> + * @copyright 2005, 2006 Alexander Valyalkin + * @license http://www.php.net/license/3_0.txt PHP License 3.0 + * @link http://pear.php.net/package/Crypt_RSA + * @version @package_version@ + * @access public + */ +class Crypt_RSA_Math_GMP +{ + /** + * error description + * + * @var string + * @access public + */ + var $errstr = ''; + + /** + * Crypt_RSA_Math_GMP constructor. + * Checks an existance of PHP GMP package. + * See http://php.net/gmp for details. + * + * On failure saves error description in $this->errstr + * + * @access public + */ + function Crypt_RSA_Math_GMP() + { + if (!extension_loaded('gmp')) { + if (!@dl('gmp.' . PHP_SHLIB_SUFFIX) && !@dl('php_gmp.' . PHP_SHLIB_SUFFIX)) { + // cannot load GMP extension + $this->errstr = 'Crypt_RSA package requires PHP GMP package. ' . + 'See http://php.net/gmp for details'; + return; + } + } + } + + /** + * Transforms binary representation of large integer into its native form. + * + * Example of transformation: + * $str = "\x12\x34\x56\x78\x90"; + * $num = 0x9078563412; + * + * @param string $str + * @return gmp resource + * @access public + */ + function bin2int($str) + { + $result = 0; + $n = strlen($str); + do { + // dirty hack: GMP returns FALSE, when second argument equals to int(0). + // so, it must be converted to string '0' + $result = gmp_add(gmp_mul($result, 256), strval(ord($str{--$n}))); + } while ($n > 0); + return $result; + } + + /** + * Transforms large integer into binary representation. + * + * Example of transformation: + * $num = 0x9078563412; + * $str = "\x12\x34\x56\x78\x90"; + * + * @param gmp resource $num + * @return string + * @access public + */ + function int2bin($num) + { + $result = ''; + do { + $result .= chr(gmp_intval(gmp_mod($num, 256))); + $num = gmp_div($num, 256); + } while (gmp_cmp($num, 0)); + return $result; + } + + /** + * Calculates pow($num, $pow) (mod $mod) + * + * @param gmp resource $num + * @param gmp resource $pow + * @param gmp resource $mod + * @return gmp resource + * @access public + */ + function powmod($num, $pow, $mod) + { + return gmp_powm($num, $pow, $mod); + } + + /** + * Calculates $num1 * $num2 + * + * @param gmp resource $num1 + * @param gmp resource $num2 + * @return gmp resource + * @access public + */ + function mul($num1, $num2) + { + return gmp_mul($num1, $num2); + } + + /** + * Calculates $num1 % $num2 + * + * @param string $num1 + * @param string $num2 + * @return string + * @access public + */ + function mod($num1, $num2) + { + return gmp_mod($num1, $num2); + } + + /** + * Compares abs($num1) to abs($num2). + * Returns: + * -1, if abs($num1) < abs($num2) + * 0, if abs($num1) == abs($num2) + * 1, if abs($num1) > abs($num2) + * + * @param gmp resource $num1 + * @param gmp resource $num2 + * @return int + * @access public + */ + function cmpAbs($num1, $num2) + { + return gmp_cmp($num1, $num2); + } + + /** + * Tests $num on primality. Returns true, if $num is strong pseudoprime. + * Else returns false. + * + * @param string $num + * @return bool + * @access private + */ + function isPrime($num) + { + return gmp_prob_prime($num) ? true : false; + } + + /** + * Generates prime number with length $bits_cnt + * using $random_generator as random generator function. + * + * @param int $bits_cnt + * @param string $rnd_generator + * @access public + */ + function getPrime($bits_cnt, $random_generator) + { + $bytes_n = intval($bits_cnt / 8); + $bits_n = $bits_cnt % 8; + do { + $str = ''; + for ($i = 0; $i < $bytes_n; $i++) { + $str .= chr(call_user_func($random_generator) & 0xff); + } + $n = call_user_func($random_generator) & 0xff; + $n |= 0x80; + $n >>= 8 - $bits_n; + $str .= chr($n); + $num = $this->bin2int($str); + + // search for the next closest prime number after [$num] + if (!gmp_cmp(gmp_mod($num, '2'), '0')) { + $num = gmp_add($num, '1'); + } + while (!gmp_prob_prime($num)) { + $num = gmp_add($num, '2'); + } + } while ($this->bitLen($num) != $bits_cnt); + return $num; + } + + /** + * Calculates $num - 1 + * + * @param gmp resource $num + * @return gmp resource + * @access public + */ + function dec($num) + { + return gmp_sub($num, 1); + } + + /** + * Returns true, if $num is equal to one. Else returns false + * + * @param gmp resource $num + * @return bool + * @access public + */ + function isOne($num) + { + return !gmp_cmp($num, 1); + } + + /** + * Finds greatest common divider (GCD) of $num1 and $num2 + * + * @param gmp resource $num1 + * @param gmp resource $num2 + * @return gmp resource + * @access public + */ + function GCD($num1, $num2) + { + return gmp_gcd($num1, $num2); + } + + /** + * Finds inverse number $inv for $num by modulus $mod, such as: + * $inv * $num = 1 (mod $mod) + * + * @param gmp resource $num + * @param gmp resource $mod + * @return gmp resource + * @access public + */ + function invmod($num, $mod) + { + return gmp_invert($num, $mod); + } + + /** + * Returns bit length of number $num + * + * @param gmp resource $num + * @return int + * @access public + */ + function bitLen($num) + { + $tmp = $this->int2bin($num); + $bit_len = strlen($tmp) * 8; + $tmp = ord($tmp{strlen($tmp) - 1}); + if (!$tmp) { + $bit_len -= 8; + } + else { + while (!($tmp & 0x80)) { + $bit_len--; + $tmp <<= 1; + } + } + return $bit_len; + } + + /** + * Calculates bitwise or of $num1 and $num2, + * starting from bit $start_pos for number $num1 + * + * @param gmp resource $num1 + * @param gmp resource $num2 + * @param int $start_pos + * @return gmp resource + * @access public + */ + function bitOr($num1, $num2, $start_pos) + { + $start_byte = intval($start_pos / 8); + $start_bit = $start_pos % 8; + $tmp1 = $this->int2bin($num1); + + $num2 = gmp_mul($num2, 1 << $start_bit); + $tmp2 = $this->int2bin($num2); + if ($start_byte < strlen($tmp1)) { + $tmp2 |= substr($tmp1, $start_byte); + $tmp1 = substr($tmp1, 0, $start_byte) . $tmp2; + } + else { + $tmp1 = str_pad($tmp1, $start_byte, "\0") . $tmp2; + } + return $this->bin2int($tmp1); + } + + /** + * Returns part of number $num, starting at bit + * position $start with length $length + * + * @param gmp resource $num + * @param int start + * @param int length + * @return gmp resource + * @access public + */ + function subint($num, $start, $length) + { + $start_byte = intval($start / 8); + $start_bit = $start % 8; + $byte_length = intval($length / 8); + $bit_length = $length % 8; + if ($bit_length) { + $byte_length++; + } + $num = gmp_div($num, 1 << $start_bit); + $tmp = substr($this->int2bin($num), $start_byte, $byte_length); + $tmp = str_pad($tmp, $byte_length, "\0"); + $tmp = substr_replace($tmp, $tmp{$byte_length - 1} & chr(0xff >> (8 - $bit_length)), $byte_length - 1, 1); + return $this->bin2int($tmp); + } + + /** + * Returns name of current wrapper + * + * @return string name of current wrapper + * @access public + */ + function getWrapperName() + { + return 'GMP'; + } +} + +?>
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