MD5

头文件：

#ifndef MD5_H  #define MD5_H  #include <string>  #include <fstream>  /* Type define */typedef unsigned char byte;typedef unsigned long ulong;using std::string;using std::ifstream;/* MD5 declaration. */class MD5 {public:MD5();MD5(const void *input, size_t length);MD5(const string &str);MD5(ifstream &in);void update(const void *input, size_t length);void update(const string &str);void update(ifstream &in);const byte* digest();string toString();void reset();private:void update(const byte *input, size_t length);void final();void transform(const byte block[64]);void encode(const ulong *input, byte *output, size_t length);void decode(const byte *input, ulong *output, size_t length);string bytesToHexString(const byte *input, size_t length);/* class uncopyable */MD5(const MD5&);MD5& operator=(const MD5&);private:ulong _state[4];    /* state (ABCD) */ulong _count[2];    /* number of bits, modulo 2^64 (low-order word first) */byte _buffer[64];   /* input buffer */byte _digest[16];   /* message digest */bool _finished;     /* calculate finished ? */static const byte PADDING[64];  /* padding for calculate */static const char HEX[16];static const size_t BUFFER_SIZE = 1024;};#endif/*MD5_H*/  

cpp文件：

#include "md5.h"  /* 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.*/#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))  #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))  #define H(x, y, z) ((x) ^ (y) ^ (z))  #define I(x, y, z) ((y) ^ ((x) | (~z)))  /* ROTATE_LEFT rotates x left n bits.*/#define ROTATE_LEFT(x, n) (((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.*/#define FF(a, b, c, d, x, s, ac) { \(a) += F((b), (c), (d)) + (x)+ac; \(a) = ROTATE_LEFT((a), (s)); \(a) += (b); \}#define GG(a, b, c, d, x, s, ac) { \(a) += G((b), (c), (d)) + (x)+ac; \(a) = ROTATE_LEFT((a), (s)); \(a) += (b); \}#define HH(a, b, c, d, x, s, ac) { \(a) += H((b), (c), (d)) + (x)+ac; \(a) = ROTATE_LEFT((a), (s)); \(a) += (b); \}#define II(a, b, c, d, x, s, ac) { \(a) += I((b), (c), (d)) + (x)+ac; \(a) = ROTATE_LEFT((a), (s)); \(a) += (b); \}const byte MD5::PADDING[64] = { 0x80 };const char MD5::HEX[16] = {'0', '1', '2', '3','4', '5', '6', '7','8', '9', 'a', 'b','c', 'd', 'e', 'f'};/* Default construct. */MD5::MD5() {reset();}/* Construct a MD5 object with a input buffer. */MD5::MD5(const void *input, size_t length) {reset();update(input, length);}/* Construct a MD5 object with a string. */MD5::MD5(const string &str) {reset();update(str);}/* Construct a MD5 object with a file. */MD5::MD5(ifstream &in) {reset();update(in);}/* Return the message-digest */const byte* MD5::digest() {if (!_finished) {_finished = true;final();}return _digest;}/* Reset the calculate state */void MD5::reset() {_finished = false;/* reset number of bits. */_count[0] = _count[1] = 0;/* Load magic initialization constants. */_state[0] = 0x67452301;_state[1] = 0xefcdab89;_state[2] = 0x98badcfe;_state[3] = 0x10325476;}/* Updating the context with a input buffer. */void MD5::update(const void *input, size_t length) {update((const byte*)input, length);}/* Updating the context with a string. */void MD5::update(const string &str) {update((const byte*)str.c_str(), str.length());}/* Updating the context with a file. */void MD5::update(ifstream &in) {if (!in)return;std::streamsize length;char buffer[BUFFER_SIZE];while (!in.eof()) {in.read(buffer, BUFFER_SIZE);length = in.gcount();if (length > 0)update(buffer, length);}in.close();}/* MD5 block update operation. Continues an MD5 message-digestoperation, processing another message block, and updating thecontext.*/void MD5::update(const byte *input, size_t length) {ulong i, index, partLen;_finished = false;/* Compute number of bytes mod 64 */index = (ulong)((_count[0] >> 3) & 0x3f);/* update number of bits */if ((_count[0] += ((ulong)length << 3)) < ((ulong)length << 3))_count[1]++;_count[1] += ((ulong)length >> 29);partLen = 64 - index;/* transform as many times as possible. */if (length >= partLen) {memcpy(&_buffer[index], input, partLen);transform(_buffer);for (i = partLen; i + 63 < length; i += 64)transform(&input[i]);index = 0;}else {i = 0;}/* Buffer remaining input */memcpy(&_buffer[index], &input[i], length - i);}/* MD5 finalization. Ends an MD5 message-_digest operation, writing thethe message _digest and zeroizing the context.*/void MD5::final() {byte bits[8];ulong oldState[4];ulong oldCount[2];ulong index, padLen;/* Save current state and count. */memcpy(oldState, _state, 16);memcpy(oldCount, _count, 8);/* Save number of bits */encode(_count, bits, 8);/* Pad out to 56 mod 64. */index = (ulong)((_count[0] >> 3) & 0x3f);padLen = (index < 56) ? (56 - index) : (120 - index);update(PADDING, padLen);/* Append length (before padding) */update(bits, 8);/* Store state in digest */encode(_state, _digest, 16);/* Restore current state and count. */memcpy(_state, oldState, 16);memcpy(_count, oldCount, 8);}/* MD5 basic transformation. Transforms _state based on block. */void MD5::transform(const byte block[64]) {ulong a = _state[0], b = _state[1], c = _state[2], d = _state[3], x[16];decode(block, x, 64);/* 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;}/* Encodes input (ulong) into output (byte). Assumes length isa multiple of 4.*/void MD5::encode(const ulong *input, byte *output, size_t length) {for (size_t i = 0, j = 0; j<length; i++, j += 4) {output[j] = (byte)(input[i] & 0xff);output[j + 1] = (byte)((input[i] >> 8) & 0xff);output[j + 2] = (byte)((input[i] >> 16) & 0xff);output[j + 3] = (byte)((input[i] >> 24) & 0xff);}}/* Decodes input (byte) into output (ulong). Assumes length isa multiple of 4.*/void MD5::decode(const byte *input, ulong *output, size_t length) {for (size_t i = 0, j = 0; j<length; i++, j += 4) {output[i] = ((ulong)input[j]) | (((ulong)input[j + 1]) << 8) |(((ulong)input[j + 2]) << 16) | (((ulong)input[j + 3]) << 24);}}/* Convert byte array to hex string. */string MD5::bytesToHexString(const byte *input, size_t length) {string str;str.reserve(length << 1);for (size_t i = 0; i < length; i++) {int t = input[i];int a = t / 16;int b = t % 16;str.append(1, HEX[a]);str.append(1, HEX[b]);}return str;}/* Convert digest to string value */string MD5::toString() {return bytesToHexString(digest(), 16);}

main文件：

#include "md5.h"  #include <iostream>  using namespace std;/*void PrintMD5(const string &str, MD5 &md5) {cout << "MD5(\"" << str << "\") = " << md5.toString() << endl;}*//*string FileDigest(const string &file) {ifstream in(file.c_str(), ios::binary);if (!in){std::cout << "no file" << std::endl;}MD5 md5;std::streamsize length;char buffer[1024];while (!in.eof()) {in.read(buffer, 1024);length = in.gcount();if (length > 0)md5.update(buffer, length);}in.close();return md5.toString();}*/int main() {cout << MD5("abc").toString() << endl;//cout << FileDigest("D:\\staticDll.dll") << endl;return 0;}