介绍MD5的论文：http://tools.ietf.org/html/rfc1321
MD5_Global.h
// MD5_Global.h - RSAREF types and constants
// 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;
MD5.h
/////////////////////////////////////////////////////////////////
//
// MD5加密类
//
// Bode
// 2007-01-29
//
// 参考资料：
// Ronald L. Rivest (1992) "The MD5 Message-Digest Algorithm"
//
/////////////////////////////////////////////////////////////////
#include "MD5_Global.h"// MD5 context.
typedef struct {
UINT4 state[4]; // state (ABCD)
UINT4 count[2]; // number of bits, modulo 2^64 (lsb first)
unsigned char buffer[64]; // input buffer
} MD5_CTX;// MD5 Class
class MD5
{
private:
static unsigned char PADDING[64];
public:
static void MD5Init (MD5_CTX *);
static void MD5Update (MD5_CTX *, unsigned char *, unsigned int);
static void MD5Final (unsigned char [16], MD5_CTX *);
private:
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:
static void ToMD5(unsigned char [16], void *, unsigned int);
};
/////////////////////////////////////////////////////////////////
//
// MD5加密类
//
// Bode
// 2007-01-29
//
// 参考资料：
// Ronald L. Rivest (1992) "The MD5 Message-Digest Algorithm"
//
/////////////////////////////////////////////////////////////////
#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) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
unsigned
char MD5::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
};// MD5 initialization. Begins an MD5 operation, writing a new context.
void MD5::MD5Init (MD5_CTX *context)
{
context->count[0] = context->count[1] = 0;
// Load magic initialization constants.
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}// MD5 block update operation. Continues an MD5 message-digest
//operation, processing another message block, and updating the
//context.
void MD5::MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
{
unsigned int i, index, partLen;// Compute number of bytes mod 64
index = (unsigned int)((context->count[0] >> 3) & 0x3F);// Update number of bits
if ((context->count[0] += ((UINT4)inputLen << 3))
< ((UINT4)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29); partLen
= 64 - index;// Transform as many times as possible.
if (inputLen >= partLen) {
MD5_memcpy
((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD5Transform (context->state, context->buffer);for (i = partLen; i + 63 < inputLen; i += 64)
MD5Transform (context->state, &input[i]); index
= 0;
}
else
i = 0;// Buffer remaining input
MD5_memcpy
((POINTER)&context->buffer[index], (POINTER)&input[i],
inputLen-i);
}// MD5 finalization. Ends an MD5 message-digest operation, writing the
//the message digest and zeroizing the context.
void MD5::MD5Final (unsigned char digest[16], MD5_CTX *context)
{
unsigned char bits[8];
unsigned int index, padLen;// Save number of bits
Encode (bits, context->count, 8);// Pad out to 56 mod 64.
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update (context, PADDING, padLen);// Append length (before padding)
MD5Update (context, bits, 8);
// Store state in digest
Encode (digest, context->state, 16);// Zeroize sensitive information.
MD5_memset ((POINTER)context, 0, sizeof (*context));
}/////////////////////////////////////////////
// MD5 basic transformation. Transforms state based on block.
void MD5::MD5Transform (UINT4 state[4], unsigned char block[64])
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16]; Decode (x, block,
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;// Zeroize sensitive information.
MD5_memset ((POINTER)x, 0, sizeof (x));
}// Encodes input (UINT4) into output (unsigned char). Assumes len is
//a multiple of 4.
void MD5::Encode (unsigned char *output, UINT4 *input, unsigned int len)
{
unsigned int i, j;for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}// Decodes input (unsigned char) into output (UINT4). Assumes len is
//a multiple of 4.
void MD5::Decode (UINT4 *output, unsigned char *input, unsigned int len)
{
unsigned int i, j;for (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);
}// Note: Replace "for loop" with standard memcpy if possible.
void MD5::MD5_memcpy (POINTER output, POINTER input, unsigned int len)
{
unsigned int i;for (i = 0; i < len; i++)
output[i] = input[i];
}// Note: Replace "for loop" with standard memset if possible.
void MD5::MD5_memset (POINTER output, int value, unsigned int len)
{
unsigned int i;for (i = 0; i < len; i++)
((char *)output)[i] = (char)value;
}//
void MD5::ToMD5(unsigned char digest[16], void *input, unsigned int inputLen)
{
MD5_CTX context; MD5Init (
&context);
MD5Update (&context, (unsigned char *)input, inputLen);
MD5Final (digest, &context);
}
测试代码：
#include <stdio.h>
#include <string.h>
#include "MD5.h"
int main()
{
unsigned char digest[16];
char string[102400];
while(true)
{
scanf("%s",string);
MD5::ToMD5(digest,string,j+80000);
printf ("MD5 (\"%s\") = ", string);
for (int i = 0; i < 16; i++)
printf ("%02x", digest[i]);
printf ("\n");
}
return 0;
}
