/* 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.
 */
#include "tomcrypt.h"

/**
   @param md4.c
   Submitted by Dobes Vandermeer  ([email protected])
*/

#ifdef LTC_MD4

const struct ltc_hash_descriptor md4_desc =
{
    "md4",
    6,
    16,
    64,

    /* OID */
   { 1, 2, 840, 113549, 2, 4,  },
   6,

    &md4_init,
    &md4_process,
    &md4_done,
    &md4_test,
    NULL
};

#define S11 3
#define S12 7
#define S13 11
#define S14 19
#define S21 3
#define S22 5
#define S23 9
#define S24 13
#define S31 3
#define S32 9
#define S33 11
#define S34 15

/* F, G and H are basic LTC_MD4 functions. */
#define F(x, y, z) (z ^ (x & (y ^ z)))
#define G(x, y, z) ((x & y) | (z & (x | y)))
#define H(x, y, z) ((x) ^ (y) ^ (z))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) ROLc(x, n)

/* FF, GG and HH are transformations for rounds 1, 2 and 3 */
/* Rotation is separate from addition to prevent recomputation */

#define FF(a, b, c, d, x, s) { \
    (a) += F ((b), (c), (d)) + (x); \
    (a) = ROTATE_LEFT ((a), (s)); \
  }
#define GG(a, b, c, d, x, s) { \
    (a) += G ((b), (c), (d)) + (x) + 0x5a827999UL; \
    (a) = ROTATE_LEFT ((a), (s)); \
  }
#define HH(a, b, c, d, x, s) { \
    (a) += H ((b), (c), (d)) + (x) + 0x6ed9eba1UL; \
    (a) = ROTATE_LEFT ((a), (s)); \
  }

#ifdef LTC_CLEAN_STACK
static int _md4_compress(hash_state *md, unsigned char *buf)
#else
static int  md4_compress(hash_state *md, unsigned char *buf)
#endif
{
    ulong32 x[16], a, b, c, d;
    int i;

    /* copy state */
    a = md->md4.state[0];
    b = md->md4.state[1];
    c = md->md4.state[2];
    d = md->md4.state[3];

    /* copy the state into 512-bits into W[0..15] */
    for (i = 0; i < 16; i++) {
        LOAD32L(x[i], buf + (4*i));
    }

    /* Round 1 */
    FF (a, b, c, d, x[ 0], S11); /* 1 */
    FF (d, a, b, c, x[ 1], S12); /* 2 */
    FF (c, d, a, b, x[ 2], S13); /* 3 */
    FF (b, c, d, a, x[ 3], S14); /* 4 */
    FF (a, b, c, d, x[ 4], S11); /* 5 */
    FF (d, a, b, c, x[ 5], S12); /* 6 */
    FF (c, d, a, b, x[ 6], S13); /* 7 */
    FF (b, c, d, a, x[ 7], S14); /* 8 */
    FF (a, b, c, d, x[ 8], S11); /* 9 */
    FF (d, a, b, c, x[ 9], S12); /* 10 */
    FF (c, d, a, b, x[10], S13); /* 11 */
    FF (b, c, d, a, x[11], S14); /* 12 */
    FF (a, b, c, d, x[12], S11); /* 13 */
    FF (d, a, b, c, x[13], S12); /* 14 */
    FF (c, d, a, b, x[14], S13); /* 15 */
    FF (b, c, d, a, x[15], S14); /* 16 */

    /* Round 2 */
    GG (a, b, c, d, x[ 0], S21); /* 17 */
    GG (d, a, b, c, x[ 4], S22); /* 18 */
    GG (c, d, a, b, x[ 8], S23); /* 19 */
    GG (b, c, d, a, x[12], S24); /* 20 */
    GG (a, b, c, d, x[ 1], S21); /* 21 */
    GG (d, a, b, c, x[ 5], S22); /* 22 */
    GG (c, d, a, b, x[ 9], S23); /* 23 */
    GG (b, c, d, a, x[13], S24); /* 24 */
    GG (a, b, c, d, x[ 2], S21); /* 25 */
    GG (d, a, b, c, x[ 6], S22); /* 26 */
    GG (c, d, a, b, x[10], S23); /* 27 */
    GG (b, c, d, a, x[14], S24); /* 28 */
    GG (a, b, c, d, x[ 3], S21); /* 29 */
    GG (d, a, b, c, x[ 7], S22); /* 30 */
    GG (c, d, a, b, x[11], S23); /* 31 */
    GG (b, c, d, a, x[15], S24); /* 32 */

    /* Round 3 */
    HH (a, b, c, d, x[ 0], S31); /* 33 */
    HH (d, a, b, c, x[ 8], S32); /* 34 */
    HH (c, d, a, b, x[ 4], S33); /* 35 */
    HH (b, c, d, a, x[12], S34); /* 36 */
    HH (a, b, c, d, x[ 2], S31); /* 37 */