C++获取MD5算法实现代码

#ifndef MD5_H #define MD5_H #include <string> #include <fstream> /* Type define */typedef unsigned char byte;typedef unsigned int uint32;typedef unsigned int uint4;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();  inline uint4 rotate_left(uint4 x, int n);  inline void FF(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);  inline void GG(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);  inline void HH(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);  inline void II(uint4 &a, uint4 b, uint4 c, uint4 d, uint4 x, uint4 s, uint4 ac);private:  void update(const byte *input, size_t length);  void final();  void transform(const byte block[64]);  void encode(const uint32 *input, byte *output, size_t length);  void decode(const byte *input, uint32 *output, size_t length);  string bytesToHexString(const byte *input, size_t length);  /* class uncopyable */  MD5(const MD5&);  MD5& operator=(const MD5&);private:  uint32 _state[4]; /* state (ABCD) */  uint32 _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;};string FileDigest(const string &file);#endif/*MD5_H*/

#include "md5.h" using namespace std;/* 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); ///}inline uint4 MD5::rotate_left(uint4 x, int n) {  return (x << n) | (x >> (32 - n));}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;}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) {  uint32 i, index, partLen;  _finished = false;  /* Compute number of bytes mod 64 */  index = (uint32)((_count[0] >> 3) & 0x3f);  /* update number of bits */  if ((_count[0] += ((uint32)length << 3)) < ((uint32)length << 3))    _count[1]++;  _count[1] += ((uint32)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];  uint32 oldState[4];  uint32 oldCount[2];  uint32 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 = (uint32)((_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]) {  uint32 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 uint32 *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, uint32 *output, size_t length) {  for (size_t i = 0, j = 0; j<length; i++, j += 4) {    output[i] = ((uint32)input[j]) | (((uint32)input[j + 1]) << 8) |      (((uint32)input[j + 2]) << 16) | (((uint32)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);}//得到二进制文件的MD5码string FileDigest(const string &file) {  ifstream in(file.c_str(), ios::binary);  if (!in)    return "";  MD5 md5;  md5.reset();  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();}

// Md5Test.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include "MD5.h"#include <fstream>#include <process.h>int main(){  std::ifstream of("ReadMe.txt", std::ios::in | std::ios::binary);  if (!of.is_open())return 0;  MD5 fileMd5(of);  printf("%s/r/n", fileMd5.toString().c_str());  MD5 strMd5("123456789");  printf("%s/r/n", strMd5.toString().c_str());  system("pause");  return 0;}