/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, [email protected], http://libtomcrypt.com
 */
#include "tomcrypt.h"


/**
  @file md5.c
  MD5 hash function by Tom St Denis 
*/

#ifdef MD5

const struct ltc_hash_descriptor md5_desc =
{
    "md5",
    3,
    16,
    64,

    /* OID */
   { 1, 2, 840, 113549, 2, 5,  },
   6,

    &md5_init,
    &md5_process,
    &md5_done,
    &md5_test,
    NULL
};

#define F(x,y,z)  (z ^ (x & (y ^ z)))
#define G(x,y,z)  (y ^ (z & (y ^ x)))
#define H(x,y,z)  (x^y^z)
#define I(x,y,z)  (y^(x|(~z)))

#ifdef LTC_SMALL_CODE

#define FF(a,b,c,d,M,s,t) \
    a = (a + F(b,c,d) + M + t); a = ROL(a, s) + b;

#define GG(a,b,c,d,M,s,t) \
    a = (a + G(b,c,d) + M + t); a = ROL(a, s) + b;

#define HH(a,b,c,d,M,s,t) \
    a = (a + H(b,c,d) + M + t); a = ROL(a, s) + b;

#define II(a,b,c,d,M,s,t) \
    a = (a + I(b,c,d) + M + t); a = ROL(a, s) + b;

static const unsigned char Worder[64] = {
   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,
   1,6,11,0,5,10,15,4,9,14,3,8,13,2,7,12,
   5,8,11,14,1,4,7,10,13,0,3,6,9,12,15,2,
   0,7,14,5,12,3,10,1,8,15,6,13,4,11,2,9
};

static const unsigned char Rorder[64] = {
   7,12,17,22,7,12,17,22,7,12,17,22,7,12,17,22,
   5,9,14,20,5,9,14,20,5,9,14,20,5,9,14,20,
   4,11,16,23,4,11,16,23,4,11,16,23,4,11,16,23,
   6,10,15,21,6,10,15,21,6,10,15,21,6,10,15,21
};

static const ulong32 Korder[64] = {
0xd76aa478UL, 0xe8c7b756UL, 0x242070dbUL, 0xc1bdceeeUL, 0xf57c0fafUL, 0x4787c62aUL, 0xa8304613UL, 0xfd469501UL,
0x698098d8UL, 0x8b44f7afUL, 0xffff5bb1UL, 0x895cd7beUL, 0x6b901122UL, 0xfd987193UL, 0xa679438eUL, 0x49b40821UL,
0xf61e2562UL, 0xc040b340UL, 0x265e5a51UL, 0xe9b6c7aaUL, 0xd62f105dUL, 0x02441453UL, 0xd8a1e681UL, 0xe7d3fbc8UL,
0x21e1cde6UL, 0xc33707d6UL, 0xf4d50d87UL, 0x455a14edUL, 0xa9e3e905UL, 0xfcefa3f8UL, 0x676f02d9UL, 0x8d2a4c8aUL,
0xfffa3942UL, 0x8771f681UL, 0x6d9d6122UL, 0xfde5380cUL, 0xa4beea44UL, 0x4bdecfa9UL, 0xf6bb4b60UL, 0xbebfbc70UL,
0x289b7ec6UL, 0xeaa127faUL, 0xd4ef3085UL, 0x04881d05UL, 0xd9d4d039UL, 0xe6db99e5UL, 0x1fa27cf8UL, 0xc4ac5665UL,
0xf4292244UL, 0x432aff97UL, 0xab9423a7UL, 0xfc93a039UL, 0x655b59c3UL, 0x8f0ccc92UL, 0xffeff47dUL, 0x85845dd1UL,
0x6fa87e4fUL, 0xfe2ce6e0UL, 0xa3014314UL, 0x4e0811a1UL, 0xf7537e82UL, 0xbd3af235UL, 0x2ad7d2bbUL, 0xeb86d391UL
};

#else

#define FF(a,b,c,d,M,s,t) \
    a = (a + F(b,c,d) + M + t); a = ROLc(a, s) + b;

#define GG(a,b,c,d,M,s,t) \
    a = (a + G(b,c,d) + M + t); a = ROLc(a, s) + b;

#define HH(a,b,c,d,M,s,t) \
    a = (a + H(b,c,d) + M + t); a = ROLc(a, s) + b;

#define II(a,b,c,d,M,s,t) \
    a = (a + I(b,c,d) + M + t); a = ROLc(a, s) + b;


#endif   

#ifdef LTC_CLEAN_STACK
static int _md5_compress(hash_state *md, unsigned char *buf)
#else
static int  md5_compress(hash_state *md, unsigned char *buf)
#endif
{
    ulong32 i, W[16], a, b, c, d;
#ifdef LTC_SMALL_CODE
    ulong32 t;
#endif

    /* copy the state into 512-bits into W[0..15] */
    for (i = 0; i < 16; i++) {
        LOAD32L(W[i], buf + (4*i));
    }
 
    /* copy state */
    a = md->md5.state[0];
    b = md->md5.state[1];
    c = md->md5.state[2];
    d = md->md5.state[3];

#ifdef LTC_SMALL_CODE
    for (i = 0; i < 16; ++i) {
        FF(a,b,c,d,W[Worder[i]],Rorder[i],Korder[i]);
        t = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 32; ++i) {
        GG(a,b,c,d,W[Worder[i]],Rorder[i],Korder[i]);
        t = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 48; ++i) {
        HH(a,b,c,d,W[Worder[i]],Rorder[i],Korder[i]);
        t = d; d = c; c = b; b = a; a = t;
    }

    for (; i < 64; ++i) {
        II(a,b,c,d,W[Worder[i]],Rorder[i],Korder[i]);
        t = d; d = c; c = b; b = a; a = t;
    }

#else
    FF(a,b,c,d,W[0],7,0xd76aa478UL)
    FF(d,a,b,c,W[1],12,0xe8c7b756UL)
    FF(c,d,a,b,W[2],17,0x242070dbUL)
    FF(b,c,d,a,W[3],22,0xc1bdceeeUL)
    FF(a,b,c,d,W[4],7,0xf57c0fafUL)
    FF(d,a,b,c,W[5],12,0x4787c62aUL)
    FF(c,d,a,b,W[6],17,0xa8304613UL)
    FF(b,c,d,a,W[7],22,0xfd469501UL)
    FF(a,b,c,d,W[8],7,0x698098d8UL)
    FF(d,a,b,c,W[9],12,0x8b44f7afUL)
    FF(c,d,a,b,W[10],17,0xffff5bb1UL)
    FF(b,c,d,a,W[11],22,0x895cd7beUL)
    FF(a,b,c,d,W[12],7,0x6b901122UL)
    FF(d,a,b,c,W[13],12,0xfd987193UL)
    FF(c,d,a,b,W[14],17,0xa679438eUL)
    FF(b,c,d,a,W[15],22,0x49b40821UL)
    GG(a,b,c,d,W[1],5,0xf61e2562UL)
    GG(d,a,b,c,W[6],9,0xc040b340UL)
    GG(c,d,a,b,W[11],14,0x265e5a51UL)
    GG(b,c,d,a,W[0],20,0xe9b6c7aaUL)
    GG(a,b,c,d,W[5],5,0xd62f105dUL)
    GG(d,a,b,c,W[10],9,0x02441453UL)
    GG(c,d,a,b,W[15],14,0xd8a1e681UL)
    GG(b,c,d,a,W[4],20,0xe7d3fbc8UL)
    GG(a,b,c,d,W[9],5,0x21e1cde6UL)
    GG(d,a,b,c,W[14],9,0xc33707d6UL)
    GG(c,d,a,b,W[3],14,0xf4d50d87UL)
    GG(b,c,d,a,W[8],20,0x455a14edUL)
    GG(a,b,c,d,W[13],5,0xa9e3e905UL)
    GG(d,a,b,c,W[2],9,0xfcefa3f8UL)
    GG(c,d,a,b,W[7],14,0x676f02d9UL)
    GG(b,c,d,a,W[12],20,0x8d2a4c8aUL)
    HH(a,b,c,d,W[5],4,0xfffa3942UL)
    HH(d,a,b,c,W[8],11,0x8771f681UL)
    HH(c,d,a,b,W[11],16,0x6d9d6122UL)
    HH(b,c,d,a,W[14],23,0xfde5380cUL)
    HH(a,b,c,d,W[1],4,0xa4beea44UL)
    HH(d,a,b,c,W[4],11,0x4bdecfa9UL)
    HH(c,d,a,b,W[7],16,0xf6bb4b60UL)
    HH(b,c,d,a,W[10],23,0xbebfbc70UL)
    HH(a,b,c,d,W[13],4,0x289b7ec6UL)
    HH(d,a,b,c,W[0],11,0xeaa127faUL)
    HH(c,d,a,b,W[3],16,0xd4ef3085UL)
    HH(b,c,d,a,W[6],23,0x04881d05UL)
    HH(a,b,c,d,W[9],4,0xd9d4d039UL)
    HH(d,a,b,c,W[12],11,0xe6db99e5UL)
    HH(c,d,a,b,W[15],16,0x1fa27cf8UL)
    HH(b,c,d,a,W[2],23,0xc4ac5665UL)
    II(a,b,c,d,W[0],6,0xf4292244UL)
    II(d,a,b,c,W[7],10,0x432aff97UL)
    II(c,d,a,b,W[14],15,0xab9423a7UL)
    II(b,c,d,a,W[5],21,0xfc93a039UL)
    II(a,b,c,d,W[12],6,0x655b59c3UL)
    II(d,a,b,c,W[3],10,0x8f0ccc92UL)
    II(c,d,a,b,W[10],15,0xffeff47dUL)
    II(b,c,d,a,W[1],21,0x85845dd1UL)
    II(a,b,c,d,W[8],6,0x6fa87e4fUL)
    II(d,a,b,c,W[15],10,0xfe2ce6e0UL)
    II(c,d,a,b,W[6],15,0xa3014314UL)
    II(b,c,d,a,W[13],21,0x4e0811a1UL)
    II(a,b,c,d,W[4],6,0xf7537e82UL)
    II(d,a,b,c,W[11],10,0xbd3af235UL)
    II(c,d,a,b,W[2],15,0x2ad7d2bbUL)
    II(b,c,d,a,W[9],21,0xeb86d391UL)
#endif

    md->md5.state[0] = md->md5.state[0] + a;
    md->md5.state[1] = md->md5.state[1] + b;