/*

 * MD4 (RFC-1320) message digest.

 * Modified from MD5 code by Andrey Panin <pazke@donpac.ru>

 *

 * Written by Solar Designer <solar@openwall.com> in 2001, and placed in

 * the public domain.  There's absolutely no warranty.

 *

 * This differs from Colin Plumb's older public domain implementation in

 * that no 32-bit integer data type is required, there's no compile-time

 * endianness configuration, and the function prototypes match OpenSSL's.

 * The primary goals are portability and ease of use.

 *

 * This implementation is meant to be fast, but not as fast as possible.

 * Some known optimizations are not included to reduce source code size

 * and avoid compile-time configuration.

 */

#include "lib.h"

#include "safe-memset.h"

#include "md4.h"

/*

 * The basic MD4 functions.

 */

#define F(x, y, z)  ((z) ^ ((x) & ((y) ^ (z))))

#define G(x, y, z)  (((x) & (y)) | ((x) & (z)) | ((y) & (z)))

#define H(x, y, z)  ((x) ^ (y) ^ (z))

/*

 * The MD4 transformation for all four rounds.

 */

#define STEP(f, a, b, c, d, x, s) \

  (a) += f((b), (c), (d)) + (x);   \

  (a) = ((a) << (s)) | ((a) >> (32 - (s)))

#define SET(n) \

  (ctx->block[(n)] = \

  (uint_fast32_t)ptr[(n) * 4] | \

  ((uint_fast32_t)ptr[(n) * 4 + 1] << 8) | \

  ((uint_fast32_t)ptr[(n) * 4 + 2] << 16) | \

  ((uint_fast32_t)ptr[(n) * 4 + 3] << 24))

#define GET(n) \

  (ctx->block[(n)])

/*

 * This processes one or more 64-byte data blocks, but does NOT update

 * the bit counters.  There're no alignment requirements.

 */

static const void * ATTR_NOWARN_UNUSED_RESULT ATTR_UNSIGNED_WRAPS

  ATTR_NO_SANITIZE_UNDEFINED ATTR_NO_SANITIZE_INTEGER

  ATTR_NO_SANITIZE_IMPLICIT_CONVERSION

body(struct md4_context *ctx, const void *data, size_t size)

{

  const unsigned char *ptr;

  uint32_t a, b, c, d;

  uint32_t saved_a, saved_b, saved_c, saved_d;

  ptr = data;

  a = ctx->a;

  b = ctx->b;

  c = ctx->c;

  d = ctx->d;

  do {

    saved_a = a;

    saved_b = b;

    saved_c = c;

    saved_d = d;

/* Round 1 */

    STEP(F, a, b, c, d, SET( 0),  3);

    STEP(F, d, a, b, c, SET( 1),  7);

    STEP(F, c, d, a, b, SET( 2), 11);

    STEP(F, b, c, d, a, SET( 3), 19);

    STEP(F, a, b, c, d, SET( 4),  3);

    STEP(F, d, a, b, c, SET( 5),  7);

    STEP(F, c, d, a, b, SET( 6), 11);

    STEP(F, b, c, d, a, SET( 7), 19);

    STEP(F, a, b, c, d, SET( 8),  3);

    STEP(F, d, a, b, c, SET( 9),  7);

    STEP(F, c, d, a, b, SET(10), 11);

    STEP(F, b, c, d, a, SET(11), 19);

    STEP(F, a, b, c, d, SET(12),  3);

    STEP(F, d, a, b, c, SET(13),  7);

    STEP(F, c, d, a, b, SET(14), 11);

    STEP(F, b, c, d, a, SET(15), 19);

/* Round 2 */

    STEP(G, a, b, c, d, GET( 0) + 0x5A827999,  3);

    STEP(G, d, a, b, c, GET( 4) + 0x5A827999,  5);

    STEP(G, c, d, a, b, GET( 8) + 0x5A827999,  9);

    STEP(G, b, c, d, a, GET(12) + 0x5A827999, 13);

    STEP(G, a, b, c, d, GET( 1) + 0x5A827999,  3);

    STEP(G, d, a, b, c, GET( 5) + 0x5A827999,  5);

    STEP(G, c, d, a, b, GET( 9) + 0x5A827999,  9);

    STEP(G, b, c, d, a, GET(13) + 0x5A827999, 13);

    STEP(G, a, b, c, d, GET( 2) + 0x5A827999,  3);

    STEP(G, d, a, b, c, GET( 6) + 0x5A827999,  5);

    STEP(G, c, d, a, b, GET(10) + 0x5A827999,  9);

    STEP(G, b, c, d, a, GET(14) + 0x5A827999, 13);

    STEP(G, a, b, c, d, GET( 3) + 0x5A827999,  3);

    STEP(G, d, a, b, c, GET( 7) + 0x5A827999,  5);

    STEP(G, c, d, a, b, GET(11) + 0x5A827999,  9);

    STEP(G, b, c, d, a, GET(15) + 0x5A827999, 13);

/* Round 3 */

    STEP(H, a, b, c, d, GET( 0) + 0x6ED9EBA1,  3);

    STEP(H, d, a, b, c, GET( 8) + 0x6ED9EBA1,  9);

    STEP(H, c, d, a, b, GET( 4) + 0x6ED9EBA1, 11);

    STEP(H, b, c, d, a, GET(12) + 0x6ED9EBA1, 15);

    STEP(H, a, b, c, d, GET( 2) + 0x6ED9EBA1,  3);

    STEP(H, d, a, b, c, GET(10) + 0x6ED9EBA1,  9);

    STEP(H, c, d, a, b, GET( 6) + 0x6ED9EBA1, 11);

    STEP(H, b, c, d, a, GET(14) + 0x6ED9EBA1, 15);

    STEP(H, a, b, c, d, GET( 1) + 0x6ED9EBA1,  3);

    STEP(H, d, a, b, c, GET( 9) + 0x6ED9EBA1,  9);

    STEP(H, c, d, a, b, GET( 5) + 0x6ED9EBA1, 11);

    STEP(H, b, c, d, a, GET(13) + 0x6ED9EBA1, 15);

    STEP(H, a, b, c, d, GET( 3) + 0x6ED9EBA1,  3);

    STEP(H, d, a, b, c, GET(11) + 0x6ED9EBA1,  9);

    STEP(H, c, d, a, b, GET( 7) + 0x6ED9EBA1, 11);

    STEP(H, b, c, d, a, GET(15) + 0x6ED9EBA1, 15);

    a += saved_a;

    b += saved_b;

    c += saved_c;

    d += saved_d;

    ptr += 64;

  } while ((size -= 64) != 0);

  ctx->a = a;

  ctx->b = b;

  ctx->c = c;

  ctx->d = d;

  return ptr;

}

void md4_init(struct md4_context *ctx)

{

  ctx->a = 0x67452301;

  ctx->b = 0xefcdab89;

  ctx->c = 0x98badcfe;

  ctx->d = 0x10325476;

  ctx->lo = 0;

  ctx->hi = 0;

}

void md4_update(struct md4_context *ctx, const void *data, size_t size)

{

  /* @UNSAFE */

  uint_fast32_t saved_lo;

  unsigned long used, free;

  if (size == 0)

    return;

  saved_lo = ctx->lo;

  if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)

    ctx->hi++;

  ctx->hi += size >> 29;

  used = saved_lo & 0x3f;

  if (used != 0) {

    free = 64 - used;

    if (size < free) {

      memcpy(&ctx->buffer[used], data, size);

      return;

    }

    memcpy(&ctx->buffer[used], data, free);

    data = (const unsigned char *) data + free;

    size -= free;

    body(ctx, ctx->buffer, 64);

  }

  if (size >= 64) {

    data = body(ctx, data, size & ~0x3fUL);

    size &= 0x3f;

  }

  memcpy(ctx->buffer, data, size);

}

void ATTR_NO_SANITIZE_UNDEFINED ATTR_NO_SANITIZE_INTEGER

  ATTR_NO_SANITIZE_IMPLICIT_CONVERSION

md4_final(struct md4_context *ctx, unsigned char result[STATIC_ARRAY MD4_RESULTLEN])

{

  /* @UNSAFE */

  unsigned long used, free;

  used = ctx->lo & 0x3f;

  ctx->buffer[used++] = 0x80;

  free = 64 - used;

  if (free < 8) {

    memset(&ctx->buffer[used], 0, free);

    body(ctx, ctx->buffer, 64);

    used = 0;

    free = 64;

  }

  memset(&ctx->buffer[used], 0, free - 8);

  ctx->lo <<= 3;

  ctx->buffer[56] = ctx->lo;

  ctx->buffer[57] = ctx->lo >> 8;

  ctx->buffer[58] = ctx->lo >> 16;

  ctx->buffer[59] = ctx->lo >> 24;

  ctx->buffer[60] = ctx->hi;

  ctx->buffer[61] = ctx->hi >> 8;

  ctx->buffer[62] = ctx->hi >> 16;

  ctx->buffer[63] = ctx->hi >> 24;

  body(ctx, ctx->buffer, 64);

  result[0] = ctx->a;

  result[1] = ctx->a >> 8;

  result[2] = ctx->a >> 16;

  result[3] = ctx->a >> 24;

  result[4] = ctx->b;

  result[5] = ctx->b >> 8;

  result[6] = ctx->b >> 16;

  result[7] = ctx->b >> 24;

  result[8] = ctx->c;

  result[9] = ctx->c >> 8;

  result[10] = ctx->c >> 16;

  result[11] = ctx->c >> 24;

  result[12] = ctx->d;

  result[13] = ctx->d >> 8;

  result[14] = ctx->d >> 16;

  result[15] = ctx->d >> 24;

  i_zero_safe(ctx);

}

void md4_get_digest(const void *data, size_t size,

        unsigned char result[STATIC_ARRAY MD4_RESULTLEN])

{

  struct md4_context ctx;

  md4_init(&ctx);

  md4_update(&ctx, data, size);

  md4_final(&ctx, result);

}

static void hash_method_init_md4(void *context)

{

  md4_init(context);

}

static void hash_method_loop_md4(void *context, const void *data, size_t size)

{

  md4_update(context, data, size);

}

static void hash_method_result_md4(void *context, unsigned char *result_r)

{

  md4_final(context, result_r);

}

const struct hash_method hash_method_md4 = {

  .name = "md4",

  .block_size = 64, /* block size is 512 bits */

  .context_size = sizeof(struct md4_context),

  .digest_size = MD4_RESULTLEN,

  .init = hash_method_init_md4,

  .loop = hash_method_loop_md4,

  .result = hash_method_result_md4,

};