首页 > 代码库 > C++ md5 函数
C++ md5 函数
转 http://www.zedwood.com/article/cpp-md5-function
MD5 is no longer considered cryptographically safe for digital signatures, however, because the md5 hash function is still useful for other purposes, code is provided below.
SHA2 (usually sha256) is recommended for new applications for digital signatures and collision resistance instead of md5 or sha1. For password hashing, even sha2 and sha3 functions are insufficient on their own. A good password hashing algorithm needs to cryptographically safe, use a unique random salt for each hash (which can be safely stored with the hash), and have an adjustable work factor. Blowfish is therefore considered the best choice for password hashing.
main.cpp
#include <iostream>#include "md5.h" using std::cout; using std::endl; int main(int argc, char *argv[]){ cout << "md5 of ‘grape‘: " << md5("grape") << endl; return 0;}
compile and run in linux:
g++ main.cpp md5.cpp -o md5_sample && ./md5_sample
output:
md5 of ‘grape‘: b781cbb29054db12f88f08c6e161c199
md5.h
/* MD5 converted to C++ class by Frank Thilo (thilo@unix-ag.org) for bzflag (http://www.bzflag.org) based on: md5.h and md5.c reference implementation of RFC 1321 Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. Allrights reserved. License to copy and use this software is granted provided that itis identified as the "RSA Data Security, Inc. MD5 Message-DigestAlgorithm" in all material mentioning or referencing this softwareor this function. License is also granted to make and use derivative works providedthat such works are identified as "derived from the RSA DataSecurity, Inc. MD5 Message-Digest Algorithm" in all materialmentioning or referencing the derived work. RSA Data Security, Inc. makes no representations concerning eitherthe merchantability of this software or the suitability of thissoftware for any particular purpose. It is provided "as is"without express or implied warranty of any kind. These notices must be retained in any copies of any part of thisdocumentation and/or software. */ #ifndef BZF_MD5_H#define BZF_MD5_H #include <cstring>#include <iostream> // a small class for calculating MD5 hashes of strings or byte arrays// it is not meant to be fast or secure//// usage: 1) feed it blocks of uchars with update()// 2) finalize()// 3) get hexdigest() string// or// MD5(std::string).hexdigest()//// assumes that char is 8 bit and int is 32 bitclass MD5{public: typedef unsigned int size_type; // must be 32bit MD5(); MD5(const std::string& text); void update(const unsigned char *buf, size_type length); void update(const char *buf, size_type length); MD5& finalize(); std::string hexdigest() const; friend std::ostream& operator<<(std::ostream&, MD5 md5); private: void init(); typedef unsigned char uint1; // 8bit typedef unsigned int uint4; // 32bit enum {blocksize = 64}; // VC6 won‘t eat a const static int here void transform(const uint1 block[blocksize]); static void decode(uint4 output[], const uint1 input[], size_type len); static void encode(uint1 output[], const uint4 input[], size_type len); bool finalized; uint1 buffer[blocksize]; // bytes that didn‘t fit in last 64 byte chunk uint4 count[2]; // 64bit counter for number of bits (lo, hi) uint4 state[4]; // digest so far uint1 digest[16]; // the result // low level logic operations static inline uint4 F(uint4 x, uint4 y, uint4 z); static inline uint4 G(uint4 x, uint4 y, uint4 z); static inline uint4 H(uint4 x, uint4 y, uint4 z); static inline uint4 I(uint4 x, uint4 y, uint4 z); static inline uint4 rotate_left(uint4 x, int n); static inline void FF(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac); static inline void GG(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac); static inline void HH(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac); static inline void II(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);}; std::string md5(const std::string str); #endifmd5.cpp
/* MD5 converted to C++ class by Frank Thilo (thilo@unix-ag.org) for bzflag (http://www.bzflag.org) based on: md5.h and md5.c reference implemantion of RFC 1321 Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. Allrights reserved. License to copy and use this software is granted provided that itis identified as the "RSA Data Security, Inc. MD5 Message-DigestAlgorithm" in all material mentioning or referencing this softwareor this function. License is also granted to make and use derivative works providedthat such works are identified as "derived from the RSA DataSecurity, Inc. MD5 Message-Digest Algorithm" in all materialmentioning or referencing the derived work. RSA Data Security, Inc. makes no representations concerning eitherthe merchantability of this software or the suitability of thissoftware for any particular purpose. It is provided "as is"without express or implied warranty of any kind. These notices must be retained in any copies of any part of thisdocumentation and/or software. */ /* interface header */#include "md5.h" /* system implementation headers */#include <cstdio> // Constants for MD5Transform routine.#define S11 7#define S12 12#define S13 17#define S14 22#define S21 5#define S22 9#define S23 14#define S24 20#define S31 4#define S32 11#define S33 16#define S34 23#define S41 6#define S42 10#define S43 15#define S44 21 /////////////////////////////////////////////// // F, G, H and I are basic MD5 functions.inline MD5::uint4 MD5::F(uint4 x, uint4 y, uint4 z) { return x&y | ~x&z;} inline MD5::uint4 MD5::G(uint4 x, uint4 y, uint4 z) { return x&z | y&~z;} inline MD5::uint4 MD5::H(uint4 x, uint4 y, uint4 z) { return x^y^z;} inline MD5::uint4 MD5::I(uint4 x, uint4 y, uint4 z) { return y ^ (x | ~z);} // rotate_left rotates x left n bits.inline MD5::uint4 MD5::rotate_left(uint4 x, int n) { return (x << n) | (x >> (32-n));} // FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.// Rotation is separate from addition to prevent recomputation.inline void MD5::FF(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac) { a = rotate_left(a+ F(b,c,d) + x + ac, s) + b;} inline void MD5::GG(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac) { a = rotate_left(a + G(b,c,d) + x + ac, s) + b;} inline void MD5::HH(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac) { a = rotate_left(a + H(b,c,d) + x + ac, s) + b;} inline void MD5::II(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac) { a = rotate_left(a + I(b,c,d) + x + ac, s) + b;} ////////////////////////////////////////////// // default ctor, just initailizeMD5::MD5(){ init();} ////////////////////////////////////////////// // nifty shortcut ctor, compute MD5 for string and finalize it right awayMD5::MD5(const std::string &text){ init(); update(text.c_str(), text.length()); finalize();} ////////////////////////////// void MD5::init(){ finalized=false; count[0] = 0; count[1] = 0; // load magic initialization constants. state[0] = 0x67452301; state[1] = 0xefcdab89; state[2] = 0x98badcfe; state[3] = 0x10325476;} ////////////////////////////// // decodes input (unsigned char) into output (uint4). Assumes len is a multiple of 4.void MD5::decode(uint4 output[], const uint1 input[], size_type len){ for (unsigned int i = 0, j = 0; j < len; i++, j += 4) output[i] = ((uint4)input[j]) | (((uint4)input[j+1]) << 8) | (((uint4)input[j+2]) << 16) | (((uint4)input[j+3]) << 24);} ////////////////////////////// // encodes input (uint4) into output (unsigned char). Assumes len is// a multiple of 4.void MD5::encode(uint1 output[], const uint4 input[], size_type len){ for (size_type i = 0, j = 0; j < len; i++, j += 4) { output[j] = input[i] & 0xff; output[j+1] = (input[i] >> 8) & 0xff; output[j+2] = (input[i] >> 16) & 0xff; output[j+3] = (input[i] >> 24) & 0xff; }} ////////////////////////////// // apply MD5 algo on a blockvoid MD5::transform(const uint1 block[blocksize]){ uint4 a = state[0], b = state[1], c = state[2], d = state[3], x[16]; decode (x, block, blocksize); /* Round 1 */ FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */ FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */ FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */ FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */ FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */ FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */ FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */ FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */ FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */ FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */ FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */ FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */ FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */ FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */ FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */ FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */ /* Round 2 */ GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */ GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */ GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */ GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */ GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */ GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */ GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */ GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */ GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */ GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */ GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */ GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */ GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */ GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */ GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */ GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */ /* Round 3 */ HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */ HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */ HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */ HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */ HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */ HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */ HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */ HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */ HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */ HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */ HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */ HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */ HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */ HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */ HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */ HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */ /* Round 4 */ II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */ II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */ II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */ II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */ II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */ II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */ II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */ II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */ II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */ II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */ II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */ II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */ II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */ II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */ II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */ II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */ state[0] += a; state[1] += b; state[2] += c; state[3] += d; // Zeroize sensitive information. memset(x, 0, sizeof x);} ////////////////////////////// // MD5 block update operation. Continues an MD5 message-digest// operation, processing another message blockvoid MD5::update(const unsigned char input[], size_type length){ // compute number of bytes mod 64 size_type index = count[0] / 8 % blocksize; // Update number of bits if ((count[0] += (length << 3)) < (length << 3)) count[1]++; count[1] += (length >> 29); // number of bytes we need to fill in buffer size_type firstpart = 64 - index; size_type i; // transform as many times as possible. if (length >= firstpart) { // fill buffer first, transform memcpy(&buffer[index], input, firstpart); transform(buffer); // transform chunks of blocksize (64 bytes) for (i = firstpart; i + blocksize <= length; i += blocksize) transform(&input[i]); index = 0; } else i = 0; // buffer remaining input memcpy(&buffer[index], &input[i], length-i);} ////////////////////////////// // for convenience provide a verson with signed charvoid MD5::update(const char input[], size_type length){ update((const unsigned char*)input, length);} ////////////////////////////// // MD5 finalization. Ends an MD5 message-digest operation, writing the// the message digest and zeroizing the context.MD5& MD5::finalize(){ static unsigned char padding[64] = { 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; if (!finalized) { // Save number of bits unsigned char bits[8]; encode(bits, count, 8); // pad out to 56 mod 64. size_type index = count[0] / 8 % 64; size_type padLen = (index < 56) ? (56 - index) : (120 - index); update(padding, padLen); // Append length (before padding) update(bits, 8); // Store state in digest encode(digest, state, 16); // Zeroize sensitive information. memset(buffer, 0, sizeof buffer); memset(count, 0, sizeof count); finalized=true; } return *this;} ////////////////////////////// // return hex representation of digest as stringstd::string MD5::hexdigest() const{ if (!finalized) return ""; char buf[33]; for (int i=0; i<16; i++) sprintf(buf+i*2, "%02x", digest[i]); buf[32]=0; return std::string(buf);} ////////////////////////////// std::ostream& operator<<(std::ostream& out, MD5 md5){ return out << md5.hexdigest();} ////////////////////////////// std::string md5(const std::string str){ MD5 md5 = MD5(str); return md5.hexdigest();}C++ md5 函数
声明：以上内容来自用户投稿及互联网公开渠道收集整理发布，本网站不拥有所有权，未作人工编辑处理，也不承担相关法律责任，若内容有误或涉及侵权可进行投诉： 投诉/举报 工作人员会在5个工作日内联系你，一经查实，本站将立刻删除涉嫌侵权内容。