// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <openssl/md4.h>

#include <stdlib.h>

#include <string.h>

#include <openssl/span.h>

#include "../fipsmodule/digest/md32_common.h"

#include "../internal.h"

uint8_t *MD4(const uint8_t *data, size_t len, uint8_t out[MD4_DIGEST_LENGTH]) {

  MD4_CTX ctx;

  MD4_Init(&ctx);

  MD4_Update(&ctx, data, len);

  MD4_Final(out, &ctx);

  return out;

}

// Implemented from RFC 1186 The MD4 Message-Digest Algorithm.

int MD4_Init(MD4_CTX *md4) {

  OPENSSL_memset(md4, 0, sizeof(MD4_CTX));

  md4->h[0] = 0x67452301UL;

  md4->h[1] = 0xefcdab89UL;

  md4->h[2] = 0x98badcfeUL;

  md4->h[3] = 0x10325476UL;

  return 1;

}

static void md4_block_data_order(uint32_t *state, const uint8_t *data,

                                 size_t num);

void MD4_Transform(MD4_CTX *c, const uint8_t data[MD4_CBLOCK]) {

  md4_block_data_order(c->h, data, 1);

}

namespace {

struct MD4Traits {

  using HashContext = MD4_CTX;

  static constexpr size_t kBlockSize = MD4_CBLOCK;

  static constexpr bool kLengthIsBigEndian = false;

  static void HashBlocks(uint32_t *state, const uint8_t *data,

                         size_t num_blocks) {

    md4_block_data_order(state, data, num_blocks);

  }

};

}  // namespace

int MD4_Update(MD4_CTX *c, const void *data, size_t len) {

  bssl::crypto_md32_update<MD4Traits>(

      c, bssl::Span(static_cast<const uint8_t *>(data), len));

  return 1;

}

int MD4_Final(uint8_t out[MD4_DIGEST_LENGTH], MD4_CTX *c) {

  bssl::crypto_md32_final<MD4Traits>(c);

  CRYPTO_store_u32_le(out, c->h[0]);

  CRYPTO_store_u32_le(out + 4, c->h[1]);

  CRYPTO_store_u32_le(out + 8, c->h[2]);

  CRYPTO_store_u32_le(out + 12, c->h[3]);

  return 1;

}

// As pointed out by Wei Dai <weidai@eskimo.com>, the above can be

// simplified to the code below.  Wei attributes these optimizations

// to Peter Gutmann's SHS code, and he attributes it to Rich Schroeppel.

#define F(b, c, d) ((((c) ^ (d)) & (b)) ^ (d))

#define G(b, c, d) (((b) & (c)) | ((b) & (d)) | ((c) & (d)))

#define H(b, c, d) ((b) ^ (c) ^ (d))

#define R0(a, b, c, d, k, s, t)            \

  do {                                     \

    (a) += ((k) + (t) + F((b), (c), (d))); \

    (a) = CRYPTO_rotl_u32(a, s);           \

  } while (0)

#define R1(a, b, c, d, k, s, t)            \

  do {                                     \

    (a) += ((k) + (t) + G((b), (c), (d))); \

    (a) = CRYPTO_rotl_u32(a, s);           \

  } while (0)

#define R2(a, b, c, d, k, s, t)            \

  do {                                     \

    (a) += ((k) + (t) + H((b), (c), (d))); \

    (a) = CRYPTO_rotl_u32(a, s);           \

  } while (0)

static void md4_block_data_order(uint32_t *state, const uint8_t *data,

                                 size_t num) {

  uint32_t A, B, C, D;

  uint32_t X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15;

  A = state[0];

  B = state[1];

  C = state[2];

  D = state[3];

  for (; num--;) {

    X0 = CRYPTO_load_u32_le(data);

    data += 4;

    X1 = CRYPTO_load_u32_le(data);

    data += 4;

    // Round 0

    R0(A, B, C, D, X0, 3, 0);

    X2 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X1, 7, 0);

    X3 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X2, 11, 0);

    X4 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(B, C, D, A, X3, 19, 0);

    X5 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(A, B, C, D, X4, 3, 0);

    X6 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X5, 7, 0);

    X7 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X6, 11, 0);

    X8 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(B, C, D, A, X7, 19, 0);

    X9 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(A, B, C, D, X8, 3, 0);

    X10 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X9, 7, 0);

    X11 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X10, 11, 0);

    X12 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(B, C, D, A, X11, 19, 0);

    X13 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(A, B, C, D, X12, 3, 0);

    X14 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X13, 7, 0);

    X15 = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X14, 11, 0);

    R0(B, C, D, A, X15, 19, 0);

    // Round 1

    R1(A, B, C, D, X0, 3, 0x5A827999L);

    R1(D, A, B, C, X4, 5, 0x5A827999L);

    R1(C, D, A, B, X8, 9, 0x5A827999L);

    R1(B, C, D, A, X12, 13, 0x5A827999L);

    R1(A, B, C, D, X1, 3, 0x5A827999L);

    R1(D, A, B, C, X5, 5, 0x5A827999L);

    R1(C, D, A, B, X9, 9, 0x5A827999L);

    R1(B, C, D, A, X13, 13, 0x5A827999L);

    R1(A, B, C, D, X2, 3, 0x5A827999L);

    R1(D, A, B, C, X6, 5, 0x5A827999L);

    R1(C, D, A, B, X10, 9, 0x5A827999L);

    R1(B, C, D, A, X14, 13, 0x5A827999L);

    R1(A, B, C, D, X3, 3, 0x5A827999L);

    R1(D, A, B, C, X7, 5, 0x5A827999L);

    R1(C, D, A, B, X11, 9, 0x5A827999L);

    R1(B, C, D, A, X15, 13, 0x5A827999L);

    // Round 2

    R2(A, B, C, D, X0, 3, 0x6ED9EBA1L);

    R2(D, A, B, C, X8, 9, 0x6ED9EBA1L);

    R2(C, D, A, B, X4, 11, 0x6ED9EBA1L);

    R2(B, C, D, A, X12, 15, 0x6ED9EBA1L);

    R2(A, B, C, D, X2, 3, 0x6ED9EBA1L);

    R2(D, A, B, C, X10, 9, 0x6ED9EBA1L);

    R2(C, D, A, B, X6, 11, 0x6ED9EBA1L);

    R2(B, C, D, A, X14, 15, 0x6ED9EBA1L);

    R2(A, B, C, D, X1, 3, 0x6ED9EBA1L);

    R2(D, A, B, C, X9, 9, 0x6ED9EBA1L);

    R2(C, D, A, B, X5, 11, 0x6ED9EBA1L);

    R2(B, C, D, A, X13, 15, 0x6ED9EBA1L);

    R2(A, B, C, D, X3, 3, 0x6ED9EBA1L);

    R2(D, A, B, C, X11, 9, 0x6ED9EBA1L);

    R2(C, D, A, B, X7, 11, 0x6ED9EBA1L);

    R2(B, C, D, A, X15, 15, 0x6ED9EBA1L);

    A = state[0] += A;

    B = state[1] += B;

    C = state[2] += C;

    D = state[3] += D;

  }

}