yemd5.c

#include <stdio.h>
#include "stdinc.h"
#include <memory.h>
#include "yemd5.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; \
          }

LOCAL uchar PADDING[] = {
    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,
};

LOCAL void _yemd5_encode(uchar *output, uint *input, uint len)
{
    uint 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;
    }
}

LOCAL void _yemd5_decode(uint *output, uchar *input, uint len)
{
    uint 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;
    }
}

LOCAL void _yemd5_transform(uint state[4], uchar block[64])
{
    uint a = state[0];
    uint b = state[1];
    uint c = state[2];
    uint d = state[3];
    uint x[16];
    
    _yemd5_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;
}
                         
void yemd5_init(md5_ctx_s *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;
}

void yemd5_update(md5_ctx_s *context, uchar *data, uint size)
{
    uint i = 0, index = 0, partlen = 0;
    
    index = (context->count[0] >> 3) & 0x3F;
    partlen = 64 - index;
    context->count[0] += size << 3;
    if(context->count[0] < (size << 3))
       context->count[1] ++;
    context->count[1] += size >> 29;
    if(size >= partlen) {
       memcpy(&context->buffer[index], data, partlen);
       _yemd5_transform(context->state, context->buffer);
       for(i = partlen; i + 64 <= size; i += 64)
           _yemd5_transform(context->state, data + i);
       index = 0;
    } else {
        i = 0;
    }
    memcpy(&context->buffer[index], data + i, size - i);
}

void yemd5_final(md5_ctx_s *context, uchar digest[16])
{
    uint index = 0, padlen = 0;
    uchar bits[8];
    
    index = (context->count[0] >> 3) & 0x3F;
    padlen = (index < 56)?(56-index):(120-index);
    _yemd5_encode(bits,context->count,8);
    yemd5_update(context, PADDING, padlen);
    yemd5_update(context, bits,8);
    _yemd5_encode(digest,context->state,16);
}