MD5 C++实现版本

#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*/  

  

#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); \  
}  
  
  
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-digest 
operation, processing another message block, and updating the 
context. 
*/  
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 the 
the 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 is 
a 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 is 
a 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);  
}  


#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)  
        return "";  
  
    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;  
}  

  

posted @ 2017-09-23 20:54  never_comparison  阅读(210)  评论(0编辑  收藏  举报