标签:style blog http color os io 使用 strong ar
MD5即Message-Digest Algorithm 5(信息-摘要算法5),用于确保信息传输完整一致。是计算机广泛使用的杂凑算法之一(又译摘要算法、哈希算法),主流编程语言普遍已有MD5实现。
将数据(如汉字)运算为另一固定长度值,是杂凑算法的基础原理,MD5的前身有MD2、MD3和MD4。MD5的作用是让大容量信息在用数字签名软件签署私人密钥前被"压缩"成一种保密的格式(就是把一个任意长度的字节串变换成一定长的十六进制数字串)。
对MD5算法简要的叙述可以为:MD5以512位分组来处理输入的信息,且每一分组又被划分为16个32位子分组,经过了一系列的处理后,算法的输出由四个32位分组组成,将这四个32位分组级联后将生成一个128位散列值。
在MD5算法中,首先需要对信息进行填充,使其位长对512求余的结果等于448。因此,信息的位长(Bits Length)将被扩展至N*512+448,N为一个非负整数,N可以是零。填充的方法如下,在信息的后面填充一个1和无数个0,直到满足上面的条件时才停止用0对信息的填充。然后,在这个结果后面附加一个以64位二进制表示的填充前信息长度。经过这两步的处理,信息的位长=N*512+448+64=(N+1)*512,即长度恰好是512的整数倍。这样做的原因是为满足后面处理中对信息长度的要求。总体流程如下图所示,表示第i个分组,每次的运算都由前一轮的128位结果值和第i块512bit值进行运算。初始的128位值为初试链接变量,这些参数用于第一轮的运算,以大端字节序来表示,他们分别为:A=0x01234567,B=0x89ABCDEF,C=0xFEDCBA98,D=0x76543210。
#pragma once /* POINTER defines a generic pointer type */ typedef unsigned char *POINTER; /* UINT2 defines a two byte word */ typedef unsigned short int UINT2; /* UINT4 defines a four byte word */ typedef unsigned long int UINT4; class cMd5 { private: unsigned int m_Content[16]; unsigned int m_ContentLen; unsigned int m_TotalLen; static unsigned int m_T[64]; unsigned int m_A, m_B, m_C, m_D; private: inline void FF(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s); inline void GG(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s); inline void HH(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s); inline void II(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s); inline unsigned int roateLeft(unsigned int a, unsigned int c); void transform(); /* MD5 context. */ typedef struct _MD5_CTX{ UINT4 state[4]; /* state (ABCD) */ UINT4 count[2]; /* bit ,2^64(Low before) */ unsigned char buffer[64]; /* input buffer */ } MD5_CTX; void MD5Init (MD5_CTX *); void MD5Update (MD5_CTX *, unsigned char *, unsigned int); void MD5Final (unsigned char [16], MD5_CTX *); void MD5String(char *string, long buflen, char digest[]); static void MD5Transform (UINT4 [4], unsigned char [64]); static void Encode (unsigned char *, UINT4 *, unsigned int); static void Decode (UINT4 *, unsigned char *, unsigned int); static void MD5_memcpy (POINTER, POINTER, unsigned int); static void MD5_memset (POINTER, int, unsigned int); public: cMd5(); virtual ~cMd5(); //initialize void beginCal(); //Show that no longer input data, will add a filling void endCal(); //Is initialized, input data, in endCal call before, can continue to add data void addData(unsigned char* data, unsigned int size); //End after operation, get the code unsigned char* getCode(); void clearMemoryHelper(char* p); };
#include "stdafx.h" #include "Md5.h" #include <string.h> #include <stdio.h> unsigned int cMd5::m_T[64] = { 0xD76aa478, 0xE8C7B756, 0x242070DB, 0xC1BDCEEE, 0xF57C0FAF, 0x4787C62A, 0xA8304613, 0xFD469501, 0x698098D8, 0x8B44F7AF, 0xFFFF5BB1, 0x895CD7BE, 0x6B901122, 0xFD987193, 0xA679438E, 0x49B40821, 0xF61E2562, 0xC040B340, 0x265E5A51, 0xE9B6C7AA, 0xD62F105D, 0x02441453, 0xD8A1E681, 0xE7D3FBC8, 0x21E1CDE6, 0xC33707D6, 0xF4D50D87, 0x455A14ED, 0xA9E3E905, 0xFCEFA3F8, 0x676F02D9, 0x8D2A4C8A, 0xFFFA3942, 0x8771F681, 0x6D9D6122, 0xFDE5380C, 0xA4BEEA44, 0x4BDECFA9, 0xF6BB4B60, 0xBEBFBC70, 0x289B7EC6, 0xEAA127FA, 0xD4EF3085, 0x04881D05, 0xD9D4D039, 0xE6DB99E5, 0x1FA27CF8, 0xC4AC5665, 0xF4292244, 0x432AFF97, 0xAB9423A7, 0xFC93A039, 0x655B59C3, 0x8F0CCC92, 0xFFEFF47D, 0x85845DD1, 0x6FA87E4F, 0xFE2CE6E0, 0xA3014314, 0x4E0811A1, 0xF7537E82, 0xBD3AF235, 0x2AD7D2BB, 0xEB86D391 }; cMd5::cMd5() { } cMd5::~cMd5() { } void cMd5::FF(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s) { a = b + roateLeft(a + ((b & c) | ((~b) & d)) + m_Content[k] + m_T[i], s); } void cMd5::GG(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s) { a = b + roateLeft(a + ((b & d) | (c & (~d))) + m_Content[k] + m_T[i], s); } void cMd5::HH(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s) { a = b + roateLeft(a + (b ^ c ^ d) + m_Content[k] + m_T[i], s); } void cMd5::II(unsigned int& a, unsigned int b, unsigned int c, unsigned int d, int k, int i, int s) { a = b + roateLeft(a + (c ^ (b | (~d))) + m_Content[k] + m_T[i], s); } unsigned int cMd5::roateLeft(unsigned int a, unsigned int c) { return ( (a << c) | (a >> (32-c)) ); } void cMd5::transform() { unsigned int AA, BB, CC, DD; AA = m_A; BB = m_B; CC = m_C; DD = m_D; //1 round FF(AA, BB, CC, DD, 0, 0, 7); FF(DD, AA, BB, CC, 1, 1, 12); FF(CC, DD, AA, BB, 2, 2, 17); FF(BB, CC, DD, AA, 3, 3, 22); FF(AA, BB, CC, DD, 4, 4, 7); FF(DD, AA, BB, CC, 5, 5, 12); FF(CC, DD, AA, BB, 6, 6, 17); FF(BB, CC, DD, AA, 7, 7, 22); FF(AA, BB, CC, DD, 8, 8, 7); FF(DD, AA, BB, CC, 9, 9, 12); FF(CC, DD, AA, BB, 10, 10, 17); FF(BB, CC, DD, AA, 11, 11, 22); FF(AA, BB, CC, DD, 12, 12, 7); FF(DD, AA, BB, CC, 13, 13, 12); FF(CC, DD, AA, BB, 14, 14, 17); FF(BB, CC, DD, AA, 15, 15, 22); //2 round GG(AA, BB, CC, DD, 1, 16, 5); GG(DD, AA, BB, CC, 6, 17, 9); GG(CC, DD, AA, BB, 11, 18, 14); GG(BB, CC, DD, AA, 0, 19, 20); GG(AA, BB, CC, DD, 5, 20, 5); GG(DD, AA, BB, CC, 10, 21, 9); GG(CC, DD, AA, BB, 15, 22, 14); GG(BB, CC, DD, AA, 4, 23, 20); GG(AA, BB, CC, DD, 9, 24, 5); GG(DD, AA, BB, CC, 14, 25, 9); GG(CC, DD, AA, BB, 3, 26, 14); GG(BB, CC, DD, AA, 8, 27, 20); GG(AA, BB, CC, DD, 13, 28, 5); GG(DD, AA, BB, CC, 2, 29, 9); GG(CC, DD, AA, BB, 7, 30, 14); GG(BB, CC, DD, AA, 12, 31, 20); //3 round HH(AA, BB, CC, DD, 5, 32, 4); HH(DD, AA, BB, CC, 8, 33, 11); HH(CC, DD, AA, BB, 11, 34, 16); HH(BB, CC, DD, AA, 14, 35, 23); HH(AA, BB, CC, DD, 1, 36, 4); HH(DD, AA, BB, CC, 4, 37, 11); HH(CC, DD, AA, BB, 7, 38, 16); HH(BB, CC, DD, AA, 10, 39, 23); HH(AA, BB, CC, DD, 13, 40, 4); HH(DD, AA, BB, CC, 0, 41, 11); HH(CC, DD, AA, BB, 3, 42, 16); HH(BB, CC, DD, AA, 6, 43, 23); HH(AA, BB, CC, DD, 9, 44, 4); HH(DD, AA, BB, CC, 12, 45, 11); HH(CC, DD, AA, BB, 15, 46, 16); HH(BB, CC, DD, AA, 2, 47, 23); //4 round II(AA, BB, CC, DD, 0, 48, 6); II(DD, AA, BB, CC, 7, 49, 10); II(CC, DD, AA, BB, 14, 50, 15); II(BB, CC, DD, AA, 5, 51, 21); II(AA, BB, CC, DD, 12, 52, 6); II(DD, AA, BB, CC, 3, 53, 10); II(CC, DD, AA, BB, 10, 54, 15); II(BB, CC, DD, AA, 1, 55, 21); II(AA, BB, CC, DD, 8, 56, 6); II(DD, AA, BB, CC, 15, 57, 10); II(CC, DD, AA, BB, 6, 58, 15); II(BB, CC, DD, AA, 13, 59, 21); II(AA, BB, CC, DD, 4, 60, 6); II(DD, AA, BB, CC, 11, 61, 10); II(CC, DD, AA, BB, 2, 62, 15); II(BB, CC, DD, AA, 9, 63, 21); m_A = m_A + AA; m_B = m_B + BB; m_C = m_C + CC; m_D = m_D + DD; } //initialize void cMd5::beginCal() { memset(m_Content, 0, 64); m_ContentLen = 0; m_TotalLen = 0; m_A = 0x67452301; m_B = 0xEFCDAB89; m_C = 0x98BADCFE; m_D = 0x10325476; } void cMd5::endCal() { memset((char*)m_Content + m_ContentLen, 0x80, 1); if (m_ContentLen < 56){ memset((char*)m_Content + m_ContentLen + 1, 0, 55 - m_ContentLen); } else{ memset((char*)m_Content + m_ContentLen + 1, 0, 63 - m_ContentLen); transform(); memset((char*)m_Content, 0, 56); } unsigned int h, l; h = 0; l = m_TotalLen; h |= ((l & 0x80000000) >> 31); h <<= 1; l <<= 1; h |= ((l & 0x80000000) >> 31); h <<= 1; l <<= 1; h |= ((l & 0x80000000) >> 31); h <<= 1; l <<= 1; memcpy(m_Content + 14, &l, 4); memcpy(m_Content + 15, &h, 4); transform(); } void cMd5::addData(unsigned char* data, unsigned int size) { unsigned int i = 0; unsigned int remain = 64 - m_ContentLen; if (remain > size) remain = size; memcpy(((char*)m_Content) + m_ContentLen, data, remain); i += remain; m_ContentLen += remain; m_TotalLen += remain; if (m_ContentLen < 64) return; transform(); while (i + 64 <= size) { memcpy(m_Content, data + i, 64); transform(); i += 64; m_TotalLen += 64; } m_ContentLen = size - i; m_TotalLen += m_ContentLen; memcpy(m_Content, data + i, m_ContentLen); } unsigned char* cMd5::getCode() { unsigned char * code = new unsigned char[16]; memcpy(code, &m_A, 4); memcpy(code + 4, &m_B, 4); memcpy(code + 8, &m_C, 4); memcpy(code + 12, &m_D, 4); return code; } void cMd5::clearMemoryHelper(char* p) { delete []p; }
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标签:style blog http color os io 使用 strong ar
原文地址:http://blog.csdn.net/yxstars/article/details/39031467