#include <string.h>
#include "md5.h"
#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))
#define ROTATE_LEFT(x, n) ((x << n) | (x >> (32 - n)))
#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; \
}
typedef struct
{
unsigned int count[2];
unsigned int state[4];
unsigned char buffer[64];
} md5_ctx_t;
static md5_ctx_t md5;
static unsigned char g_md5_padding[] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
static unsigned int x[64] = {0};
static void md5_encode(unsigned char *output, unsigned int *input, unsigned int len)
{
unsigned int i = 0, j = 0;
while (j < len)
{
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;
i ++;
j += 4;
}
}
static void md5_decode(unsigned int *output, unsigned char *input, unsigned int len)
{
unsigned int i = 0, j = 0;
while (j < len)
{
output[i] = (input[j]) |
(input[j + 1] << 8) |
(input[j + 2] << 16) |
(input[j + 3] << 24);
i++;
j += 4;
}
}
static void md5_transform(unsigned int state[4], unsigned char block[64])
{
unsigned int a = state[0];
unsigned int b = state[1];
unsigned int c = state[2];
unsigned int d = state[3];
md5_decode(x, block, 64);
FF(a, b, c, d, x[0], 7, 0xd76aa478); /* 1 */
FF(d, a, b, c, x[1], 12, 0xe8c7b756); /* 2 */
FF(c, d, a, b, x[2], 17, 0x242070db); /* 3 */
FF(b, c, d, a, x[3], 22, 0xc1bdceee); /* 4 */
FF(a, b, c, d, x[4], 7, 0xf57c0faf); /* 5 */
FF(d, a, b, c, x[5], 12, 0x4787c62a); /* 6 */
FF(c, d, a, b, x[6], 17, 0xa8304613); /* 7 */
FF(b, c, d, a, x[7], 22, 0xfd469501); /* 8 */
FF(a, b, c, d, x[8], 7, 0x698098d8); /* 9 */
FF(d, a, b, c, x[9], 12, 0x8b44f7af); /* 10 */
FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */
/* Round 2 */
GG(a, b, c, d, x[1], 5, 0xf61e2562); /* 17 */
GG(d, a, b, c, x[6], 9, 0xc040b340); /* 18 */
GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
GG(b, c, d, a, x[0], 20, 0xe9b6c7aa); /* 20 */
GG(a, b, c, d, x[5], 5, 0xd62f105d); /* 21 */
GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
GG(b, c, d, a, x[4], 20, 0xe7d3fbc8); /* 24 */
GG(a, b, c, d, x[9], 5, 0x21e1cde6); /* 25 */
GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
GG(c, d, a, b, x[3], 14, 0xf4d50d87); /* 27 */
GG(b, c, d, a, x[8], 20, 0x455a14ed); /* 28 */
GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
GG(d, a, b, c, x[2], 9, 0xfcefa3f8); /* 30 */
GG(c, d, a, b, x[7], 14, 0x676f02d9); /* 31 */
GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */
/* Round 3 */
HH(a, b, c, d, x[5], 4, 0xfffa3942); /* 33 */
HH(d, a, b, c, x[8], 11, 0x8771f681); /* 34 */
HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
HH(a, b, c, d, x[1], 4, 0xa4beea44); /* 37 */
HH(d, a, b, c, x[4], 11, 0x4bdecfa9); /* 38 */
HH(c, d, a, b, x[7], 16, 0xf6bb4b60); /* 39 */
HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
HH(d, a, b, c, x[0], 11, 0xeaa127fa); /* 42 */
HH(c, d, a, b, x[3], 16, 0xd4ef3085); /* 43 */
HH(b, c, d, a, x[6], 23, 0x4881d05); /* 44 */
HH(a, b, c, d, x[9], 4, 0xd9d4d039); /* 45 */
HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
HH(b, c, d, a, x[2], 23, 0xc4ac5665); /* 48 */
/* Round 4 */
II(a, b, c, d, x[0], 6, 0xf4292244); /* 49 */
II(d, a, b, c, x[7], 10, 0x432aff97); /* 50 */
II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
II(b, c, d, a, x[5], 21, 0xfc93a039); /* 52 */
II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
II(d, a, b, c, x[3], 10, 0x8f0ccc92); /* 54 */
II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
II(b, c, d, a, x[1], 21, 0x85845dd1); /* 56 */
II(a, b, c, d, x[8], 6, 0x6fa87e4f); /* 57 */
II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
II(c, d, a, b, x[6], 15, 0xa3014314); /* 59 */
II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
II(a, b, c, d, x[4], 6, 0xf7537e82); /* 61 */
II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
II(c, d, a, b, x[2], 15, 0x2ad7d2bb); /* 63 */
II(b, c, d, a, x[9], 21, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
static void md5_init(md5_ctx_t *context)
{
context->count[0] = 0;
context->count[1] = 0;
context->state[0] = 0x67452301;
context->state[1] = 0xEFCDAB89;
context->state[2] = 0x98BADCFE;
context->state[3] = 0x10325476;
}
static void md5_update(md5_ctx_t *context, unsigned char *input, unsigned int inputlen)
{
unsigned int i = 0, index = 0, partlen = 0;
index = (context->count[0] >> 3) & 0x3F;
partlen = 64 - index;
context->count[0] += inputlen << 3;
if (context->count[0] < (inputlen << 3))
context->count[1]++;
context->count[1] += inputlen >> 29;
if (inputlen >= partlen)
{
memcpy(&context->buffer[index], input, partlen);
md5_transform(context->state, context->buffer);
for (i = partlen; i + 64 <= inputlen; i += 64)
md5_transform(context->state, &input[i]);
index = 0;
}
else
{
i = 0;
}
memcpy(&context->buffer[index], &input[i], inputlen - i);
}
static void md5_start(md5_ctx_t *context, unsigned char *input, unsigned int len)
{
md5_update(context, input, len);
}
static void md5_process(md5_ctx_t *context)
{
unsigned int index = 0, padlen = 0;
unsigned char bits[8];
index = (context->count[0] >> 3) & 0x3F;
padlen = (index < 56) ? (56 - index) : (120 - index);
md5_encode(bits, context->count, 8);
md5_update(context, g_md5_padding, padlen);
md5_update(context, bits, 8);
}
static void md5_final(md5_ctx_t *context, unsigned char *digest)
{
md5_encode(digest, context->state, 16);
}
void md5_sign(unsigned char *input, unsigned int input_len, unsigned char *output)
{
md5_init(&md5);
md5_start(&md5, input, input_len);
md5_process(&md5);
md5_final(&md5, output);
}
#ifndef _MD5_H
#define _MD5_H
void md5_sign(unsigned char *input, unsigned int input_len, unsigned char *output);
#endif
使用例子伪代码
char buff[16];
md5_sign("xjq",3,buff);
