// 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/md5.h>

#include <string.h>

#include <openssl/mem.h>

#include <openssl/span.h>

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

#include "../internal.h"

#include "internal.h"

using namespace bssl;

uint8_t *MD5(const uint8_t *data, size_t len, uint8_t out[MD5_DIGEST_LENGTH]) {

  MD5_CTX ctx;

  MD5_Init(&ctx);

  MD5_Update(&ctx, data, len);

  MD5_Final(out, &ctx);

  return out;

}

int MD5_Init(MD5_CTX *md5) {

  OPENSSL_memset(md5, 0, sizeof(MD5_CTX));

  md5->h[0] = 0x67452301UL;

  md5->h[1] = 0xefcdab89UL;

  md5->h[2] = 0x98badcfeUL;

  md5->h[3] = 0x10325476UL;

  return 1;

}

#if defined(MD5_ASM)

#define md5_block_data_order md5_block_asm_data_order

#else

static void md5_block_data_order(uint32_t *state, const uint8_t *data,

                                 size_t num);

#endif

void MD5_Transform(MD5_CTX *c, const uint8_t data[MD5_CBLOCK]) {

  md5_block_data_order(c->h, data, 1);

}

namespace {

struct MD5Traits {

  using HashContext = MD5_CTX;

  static constexpr size_t kBlockSize = MD5_CBLOCK;

  static constexpr bool kLengthIsBigEndian = false;

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

                         size_t num_blocks) {

    md5_block_data_order(state, data, num_blocks);

  }

};

}  // namespace

int MD5_Update(MD5_CTX *c, const void *data, size_t len) {

  crypto_md32_update<MD5Traits>(c,

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

  return 1;

}

int MD5_Final(uint8_t out[MD5_DIGEST_LENGTH], MD5_CTX *c) {

  crypto_md32_final<MD5Traits>(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)) & (d)) ^ (c))

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

#define I(b, c, d) (((~(d)) | (b)) ^ (c))

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

  do {                                     \

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

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

    (a) += (b);                            \

  } 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);           \

    (a) += (b);                            \

  } 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);           \

    (a) += (b);                            \

  } while (0)

#define R3(a, b, c, d, k, s, t)            \

  do {                                     \

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

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

    (a) += (b);                            \

  } while (0)

#ifndef MD5_ASM

#ifdef X

#undef X

#endif

static void md5_block_data_order(uint32_t *state, const uint8_t *data,

                                 size_t num) {

  uint32_t A, B, C, D;

  uint32_t XX0, XX1, XX2, XX3, XX4, XX5, XX6, XX7, XX8, XX9, XX10, XX11, XX12,

      XX13, XX14, XX15;

#define X(i) XX##i

  A = state[0];

  B = state[1];

  C = state[2];

  D = state[3];

  for (; num--;) {

    X(0) = CRYPTO_load_u32_le(data);

    data += 4;

    X(1) = CRYPTO_load_u32_le(data);

    data += 4;

    // Round 0

    R0(A, B, C, D, X(0), 7, 0xd76aa478L);

    X(2) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X(1), 12, 0xe8c7b756L);

    X(3) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X(2), 17, 0x242070dbL);

    X(4) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(B, C, D, A, X(3), 22, 0xc1bdceeeL);

    X(5) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(A, B, C, D, X(4), 7, 0xf57c0fafL);

    X(6) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X(5), 12, 0x4787c62aL);

    X(7) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X(6), 17, 0xa8304613L);

    X(8) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(B, C, D, A, X(7), 22, 0xfd469501L);

    X(9) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(A, B, C, D, X(8), 7, 0x698098d8L);

    X(10) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X(9), 12, 0x8b44f7afL);

    X(11) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X(10), 17, 0xffff5bb1L);

    X(12) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(B, C, D, A, X(11), 22, 0x895cd7beL);

    X(13) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(A, B, C, D, X(12), 7, 0x6b901122L);

    X(14) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(D, A, B, C, X(13), 12, 0xfd987193L);

    X(15) = CRYPTO_load_u32_le(data);

    data += 4;

    R0(C, D, A, B, X(14), 17, 0xa679438eL);

    R0(B, C, D, A, X(15), 22, 0x49b40821L);

    // Round 1

    R1(A, B, C, D, X(1), 5, 0xf61e2562L);

    R1(D, A, B, C, X(6), 9, 0xc040b340L);

    R1(C, D, A, B, X(11), 14, 0x265e5a51L);

    R1(B, C, D, A, X(0), 20, 0xe9b6c7aaL);

    R1(A, B, C, D, X(5), 5, 0xd62f105dL);

    R1(D, A, B, C, X(10), 9, 0x02441453L);

    R1(C, D, A, B, X(15), 14, 0xd8a1e681L);

    R1(B, C, D, A, X(4), 20, 0xe7d3fbc8L);

    R1(A, B, C, D, X(9), 5, 0x21e1cde6L);

    R1(D, A, B, C, X(14), 9, 0xc33707d6L);

    R1(C, D, A, B, X(3), 14, 0xf4d50d87L);

    R1(B, C, D, A, X(8), 20, 0x455a14edL);

    R1(A, B, C, D, X(13), 5, 0xa9e3e905L);

    R1(D, A, B, C, X(2), 9, 0xfcefa3f8L);

    R1(C, D, A, B, X(7), 14, 0x676f02d9L);

    R1(B, C, D, A, X(12), 20, 0x8d2a4c8aL);

    // Round 2

    R2(A, B, C, D, X(5), 4, 0xfffa3942L);

    R2(D, A, B, C, X(8), 11, 0x8771f681L);

    R2(C, D, A, B, X(11), 16, 0x6d9d6122L);

    R2(B, C, D, A, X(14), 23, 0xfde5380cL);

    R2(A, B, C, D, X(1), 4, 0xa4beea44L);

    R2(D, A, B, C, X(4), 11, 0x4bdecfa9L);

    R2(C, D, A, B, X(7), 16, 0xf6bb4b60L);

    R2(B, C, D, A, X(10), 23, 0xbebfbc70L);

    R2(A, B, C, D, X(13), 4, 0x289b7ec6L);

    R2(D, A, B, C, X(0), 11, 0xeaa127faL);

    R2(C, D, A, B, X(3), 16, 0xd4ef3085L);

    R2(B, C, D, A, X(6), 23, 0x04881d05L);

    R2(A, B, C, D, X(9), 4, 0xd9d4d039L);

    R2(D, A, B, C, X(12), 11, 0xe6db99e5L);

    R2(C, D, A, B, X(15), 16, 0x1fa27cf8L);

    R2(B, C, D, A, X(2), 23, 0xc4ac5665L);

    // Round 3

    R3(A, B, C, D, X(0), 6, 0xf4292244L);

    R3(D, A, B, C, X(7), 10, 0x432aff97L);

    R3(C, D, A, B, X(14), 15, 0xab9423a7L);

    R3(B, C, D, A, X(5), 21, 0xfc93a039L);

    R3(A, B, C, D, X(12), 6, 0x655b59c3L);

    R3(D, A, B, C, X(3), 10, 0x8f0ccc92L);

    R3(C, D, A, B, X(10), 15, 0xffeff47dL);

    R3(B, C, D, A, X(1), 21, 0x85845dd1L);

    R3(A, B, C, D, X(8), 6, 0x6fa87e4fL);

    R3(D, A, B, C, X(15), 10, 0xfe2ce6e0L);

    R3(C, D, A, B, X(6), 15, 0xa3014314L);

    R3(B, C, D, A, X(13), 21, 0x4e0811a1L);

    R3(A, B, C, D, X(4), 6, 0xf7537e82L);

    R3(D, A, B, C, X(11), 10, 0xbd3af235L);

    R3(C, D, A, B, X(2), 15, 0x2ad7d2bbL);

    R3(B, C, D, A, X(9), 21, 0xeb86d391L);

    A = state[0] += A;

    B = state[1] += B;

    C = state[2] += C;

    D = state[3] += D;

  }

}

#undef X

#endif

#undef F

#undef G

#undef H

#undef I

#undef R0

#undef R1

#undef R2

#undef R3