标题: PHP网页设计php下的RSA算法完成 [打印本页] 作者: 只想知道 时间: 2015-2-3 23:57 标题: PHP网页设计php下的RSA算法完成 多个成员之间重复做相同的工作，很容易因为交流沟通的时候没有进行一致性的文档要求而出现不明错误，严重影响开发进度，导致在预定时间内无法完成该项目或者完成的项目跟原先计划所要实现的项目功能不符合。 /*
* Implementation of the RSA algorithm
* (C) Copyright 2004 Edsko de Vries, Ireland
*
* Licensed under the GNU Public License (GPL)
*
* This implementation has been verified against [3]
* (tested Java/PHP interoperability).
*
* References:
* [1] "Applied Cryptography", Bruce Schneier, John Wiley & Sons, 1996
* [2] "Prime Number Hide-and-Seek", Brian Raiter, Muppetlabs (online)
* [3] "The Bouncy Castle Crypto Package", Legion of the Bouncy Castle,
* (open source cryptography library for Java, online)
* [4] "PKCS #1: RSA Encryption Standard", RSA Laboratories Technical Note,
* version 1.5, revised November 1, 1993
*/
/*
* Functions that are meant to be used by the user of this PHP module.
*
* Notes:
* - $key and $modulus should be numbers in (decimal) string format
* - $message is expected to be binary data
* - $keylength should be a multiple of 8, and should be in bits
* - For rsa_encrypt/rsa_sign, the length of $message should not exceed
* ($keylength / 8) - 11 (as mandated by [4]).
* - rsa_encrypt and rsa_sign will automatically add padding to the message.
* For rsa_encrypt, this padding will consist of random values; for rsa_sign,
* padding will consist of the appropriate number of 0xFF values (see [4])
* - rsa_decrypt and rsa_verify will automatically remove message padding.
* - Blocks for decoding (rsa_decrypt, rsa_verify) should be exactly
* ($keylength / 8) bytes long.
* - rsa_encrypt and rsa_verify expect a public key; rsa_decrypt and rsa_sign
* expect a private key.
*/
/*
* The actual implementation.
* Requires BCMath support in PHP (compile with --enable-bcmath)
*/
//--
// Calculate (p ^ q) mod r
//
// We need some trickery to [2]:
// (a) Avoid calculating (p ^ q) before (p ^ q) mod r, because for typical RSA
// applications, (p ^ q) is going to be _WAY_ too large.
// (I mean, __WAY__ too large - won't fit in your computer's memory.)
// (b) Still be reasonably efficient.
//
// We assume p, q and r are all positive, and that r is non-zero.
//
// Note that the more simple algorithm of multiplying $p by itself $q times, and
// applying "mod $r" at every step is also valid, but is O($q), whereas this
// algorithm is O(log $q). Big difference.
//
// As far as I can see, the algorithm I use is optimal; there is no redundancy
// in the calculation of the partial results.
//--
function pow_mod($p, $q, $r)
{
// Extract powers of 2 from $q
$factors = array();
$div = $q;
$power_of_two = 0;
while(bccomp($div, "0") == BCCOMP_LARGER)
{
$rem = bcmod($div, 2);
$div = bcdiv($div, 2);
// Calculate partial results for each factor, using each partial result as a
// starting point for the next. This depends of the factors of two being
// generated in increasing order.
$partial_results = array();
$part_res = $p;
$idx = 0;
foreach($factors as $factor)
{
while($idx < $factor)
{
$part_res = bcpow($part_res, "2");
$part_res = bcmod($part_res, $r);
$idx++;
}
array_pus($partial_results, $part_res);
}
// Calculate final result
$result = "1";
foreach($partial_results as $part_res)
{
$result = bcmul($result, $part_res);
$result = bcmod($result, $r);
}
return $result;
}
//--
// Function to add padding to a decrypted string
// We need to know if this is a private or a public key operation [4]
//--
function add_PKCS1_padding($data, $isPublicKey, $blocksize)
{
$pad_length = $blocksize - 3 - strlen($data);
//--
// Remove padding from a decrypted string
// See [4] for more details.
//--
function remove_PKCS1_padding($data, $blocksize)
{
assert(strlen($data) == $blocksize);
$data = substr($data, 1);
// We cannot deal with block type 0
if($data{0} == '\0')
die("Block type 0 not implemented.");
// Then the block type must be 1 or 2
assert(($data{0} == "\x01") || ($data{0} == "\x02"));