/* Copyright (c) 2014, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include <memory>
#include <vector>

#include <gtest/gtest.h>

#include <openssl/asn1.h>
#include <openssl/bytestring.h>
#include <openssl/crypto.h>
#include <openssl/digest.h>
#include <openssl/err.h>
#include <openssl/md4.h>
#include <openssl/md5.h>
#include <openssl/nid.h>
#include <openssl/obj.h>
#include <openssl/sha.h>

#include "../internal.h"
#include "../test/test_util.h"


struct MD {
  // name is the name of the digest.
  const char* name;
  // md_func is the digest to test.
  const EVP_MD *(*func)(void);
  // one_shot_func is the convenience one-shot version of the
  // digest.
  uint8_t *(*one_shot_func)(const uint8_t *, size_t, uint8_t *);
};

static const MD md4 = { "MD4", &EVP_md4, nullptr };
static const MD md5 = { "MD5", &EVP_md5, &MD5 };
static const MD sha1 = { "SHA1", &EVP_sha1, &SHA1 };
static const MD sha224 = { "SHA224", &EVP_sha224, &SHA224 };
static const MD sha256 = { "SHA256", &EVP_sha256, &SHA256 };
static const MD sha384 = { "SHA384", &EVP_sha384, &SHA384 };
static const MD sha512 = { "SHA512", &EVP_sha512, &SHA512 };
static const MD sha512_256 = { "SHA512-256", &EVP_sha512_256, &SHA512_256 };
static const MD md5_sha1 = { "MD5-SHA1", &EVP_md5_sha1, nullptr };
static const MD blake2b256 = { "BLAKE2b-256", &EVP_blake2b256, nullptr };

struct DigestTestVector {
  // md is the digest to test.
  const MD &md;
  // input is a NUL-terminated string to hash.
  const char *input;
  // repeat is the number of times to repeat input.
  size_t repeat;
  // expected_hex is the expected digest in hexadecimal.
  const char *expected_hex;
};

static const DigestTestVector kTestVectors[] = {
    // MD4 tests, from RFC 1320. (crypto/md4 does not provide a
    // one-shot MD4 function.)
    {md4, "", 1, "31d6cfe0d16ae931b73c59d7e0c089c0"},
    {md4, "a", 1, "bde52cb31de33e46245e05fbdbd6fb24"},
    {md4, "abc", 1, "a448017aaf21d8525fc10ae87aa6729d"},
    {md4, "message digest", 1, "d9130a8164549fe818874806e1c7014b"},
    {md4, "abcdefghijklmnopqrstuvwxyz", 1, "d79e1c308aa5bbcdeea8ed63df412da9"},
    {md4, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 1,
     "043f8582f241db351ce627e153e7f0e4"},
    {md4, "1234567890", 8, "e33b4ddc9c38f2199c3e7b164fcc0536"},

    // MD5 tests, from RFC 1321.
    {md5, "", 1, "d41d8cd98f00b204e9800998ecf8427e"},
    {md5, "a", 1, "0cc175b9c0f1b6a831c399e269772661"},
    {md5, "abc", 1, "900150983cd24fb0d6963f7d28e17f72"},
    {md5, "message digest", 1, "f96b697d7cb7938d525a2f31aaf161d0"},
    {md5, "abcdefghijklmnopqrstuvwxyz", 1, "c3fcd3d76192e4007dfb496cca67e13b"},
    {md5, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 1,
     "d174ab98d277d9f5a5611c2c9f419d9f"},
    {md5, "1234567890", 8, "57edf4a22be3c955ac49da2e2107b67a"},

    // SHA-1 tests, from RFC 3174.
    {sha1, "abc", 1, "a9993e364706816aba3e25717850c26c9cd0d89d"},
    {sha1, "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 1,
     "84983e441c3bd26ebaae4aa1f95129e5e54670f1"},
    {sha1, "a", 1000000, "34aa973cd4c4daa4f61eeb2bdbad27316534016f"},
    {sha1, "0123456701234567012345670123456701234567012345670123456701234567",
     10, "dea356a2cddd90c7a7ecedc5ebb563934f460452"},

    // SHA-224 tests, from RFC 3874.
    {sha224, "abc", 1,
     "23097d223405d8228642a477bda255b32aadbce4bda0b3f7e36c9da7"},
    {sha224, "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 1,
     "75388b16512776cc5dba5da1fd890150b0c6455cb4f58b1952522525"},
    {sha224, "a", 1000000,
     "20794655980c91d8bbb4c1ea97618a4bf03f42581948b2ee4ee7ad67"},

    // SHA-256 tests, from NIST.
    {sha256, "abc", 1,
     "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"},
    {sha256, "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 1,
     "248d6a61d20638b8e5c026930c3e6039a33ce45964ff2167f6ecedd419db06c1"},

    // SHA-384 tests, from NIST.
    {sha384, "abc", 1,
     "cb00753f45a35e8bb5a03d699ac65007272c32ab0eded1631a8b605a43ff5bed"
     "8086072ba1e7cc2358baeca134c825a7"},
    {sha384,
     "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
     "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
     1,
     "09330c33f71147e83d192fc782cd1b4753111b173b3b05d22fa08086e3b0f712"
     "fcc7c71a557e2db966c3e9fa91746039"},

    // SHA-512 tests, from NIST.
    {sha512, "abc", 1,
     "ddaf35a193617abacc417349ae20413112e6fa4e89a97ea20a9eeee64b55d39a"
     "2192992a274fc1a836ba3c23a3feebbd454d4423643ce80e2a9ac94fa54ca49f"},
    {sha512,
     "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
     "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
     1,
     "8e959b75dae313da8cf4f72814fc143f8f7779c6eb9f7fa17299aeadb6889018"
     "501d289e4900f7e4331b99dec4b5433ac7d329eeb6dd26545e96e55b874be909"},

    // SHA-512-256 tests, from
    // https://csrc.nist.gov/csrc/media/projects/cryptographic-standards-and-guidelines/documents/examples/sha512_256.pdf
    {sha512_256, "abc", 1,
     "53048e2681941ef99b2e29b76b4c7dabe4c2d0c634fc6d46e0e2f13107e7af23"},
    {sha512_256,
     "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopj"
     "klmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
     1, "3928e184fb8690f840da3988121d31be65cb9d3ef83ee6146feac861e19b563a"},

    // MD5-SHA1 tests.
    {md5_sha1, "abc", 1,
     "900150983cd24fb0d6963f7d28e17f72a9993e364706816aba3e25717850c26c9cd0d89d"},

    // BLAKE2b-256 tests.
    {blake2b256, "abc", 1,
     "bddd813c634239723171ef3fee98579b94964e3bb1cb3e427262c8c068d52319"},
};

static void CompareDigest(const DigestTestVector *test,
                          const uint8_t *digest,
                          size_t digest_len) {
  EXPECT_EQ(test->expected_hex,
            EncodeHex(bssl::MakeConstSpan(digest, digest_len)));
}

static void TestDigest(const DigestTestVector *test) {
  bssl::ScopedEVP_MD_CTX ctx;

  // Test the input provided.
  ASSERT_TRUE(EVP_DigestInit_ex(ctx.get(), test->md.func(), NULL));
  for (size_t i = 0; i < test->repeat; i++) {
    ASSERT_TRUE(EVP_DigestUpdate(ctx.get(), test->input, strlen(test->input)));
  }
  std::unique_ptr<uint8_t[]> digest(new uint8_t[EVP_MD_size(test->md.func())]);
  unsigned digest_len;
  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), digest.get(), &digest_len));
  CompareDigest(test, digest.get(), digest_len);

  // Test the input one character at a time.
  ASSERT_TRUE(EVP_DigestInit_ex(ctx.get(), test->md.func(), NULL));
  ASSERT_TRUE(EVP_DigestUpdate(ctx.get(), NULL, 0));
  for (size_t i = 0; i < test->repeat; i++) {
    for (const char *p = test->input; *p; p++) {
      ASSERT_TRUE(EVP_DigestUpdate(ctx.get(), p, 1));
    }
  }
  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), digest.get(), &digest_len));
  EXPECT_EQ(EVP_MD_size(test->md.func()), digest_len);
  CompareDigest(test, digest.get(), digest_len);

  // Test with unaligned input.
  ASSERT_TRUE(EVP_DigestInit_ex(ctx.get(), test->md.func(), NULL));
  std::vector<char> unaligned(strlen(test->input) + 1);
  char *ptr = unaligned.data();
  if ((reinterpret_cast<uintptr_t>(ptr) & 1) == 0) {
    ptr++;
  }
  OPENSSL_memcpy(ptr, test->input, strlen(test->input));
  for (size_t i = 0; i < test->repeat; i++) {
    ASSERT_TRUE(EVP_DigestUpdate(ctx.get(), ptr, strlen(test->input)));
  }
  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), digest.get(), &digest_len));
  CompareDigest(test, digest.get(), digest_len);

  // Make a copy of the digest in the initial state.
  ASSERT_TRUE(EVP_DigestInit_ex(ctx.get(), test->md.func(), NULL));
  bssl::ScopedEVP_MD_CTX copy;
  ASSERT_TRUE(EVP_MD_CTX_copy_ex(copy.get(), ctx.get()));
  for (size_t i = 0; i < test->repeat; i++) {
    ASSERT_TRUE(EVP_DigestUpdate(copy.get(), test->input, strlen(test->input)));
  }
  ASSERT_TRUE(EVP_DigestFinal_ex(copy.get(), digest.get(), &digest_len));
  CompareDigest(test, digest.get(), digest_len);

  // Make a copy of the digest with half the input provided.
  size_t half = strlen(test->input) / 2;
  ASSERT_TRUE(EVP_DigestUpdate(ctx.get(), test->input, half));
  ASSERT_TRUE(EVP_MD_CTX_copy_ex(copy.get(), ctx.get()));
  ASSERT_TRUE(EVP_DigestUpdate(copy.get(), test->input + half,
                               strlen(test->input) - half));
  for (size_t i = 1; i < test->repeat; i++) {
    ASSERT_TRUE(EVP_DigestUpdate(copy.get(), test->input, strlen(test->input)));
  }
  ASSERT_TRUE(EVP_DigestFinal_ex(copy.get(), digest.get(), &digest_len));
  CompareDigest(test, digest.get(), digest_len);

  // Test the one-shot function.
  if (test->md.one_shot_func && test->repeat == 1) {
    uint8_t *out = test->md.one_shot_func((const uint8_t *)test->input,
                                          strlen(test->input), digest.get());
    // One-shot functions return their supplied buffers.
    EXPECT_EQ(digest.get(), out);
    CompareDigest(test, digest.get(), EVP_MD_size(test->md.func()));
  }
}

TEST(DigestTest, TestVectors) {
  for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(kTestVectors); i++) {
    SCOPED_TRACE(i);
    TestDigest(&kTestVectors[i]);
  }
}

TEST(DigestTest, Getters) {
  EXPECT_EQ(EVP_sha512(), EVP_get_digestbyname("RSA-SHA512"));
  EXPECT_EQ(EVP_sha512(), EVP_get_digestbyname("sha512WithRSAEncryption"));
  EXPECT_EQ(nullptr, EVP_get_digestbyname("nonsense"));
  EXPECT_EQ(EVP_sha512(), EVP_get_digestbyname("SHA512"));
  EXPECT_EQ(EVP_sha512(), EVP_get_digestbyname("sha512"));

  EXPECT_EQ(EVP_sha512(), EVP_get_digestbynid(NID_sha512));
  EXPECT_EQ(nullptr, EVP_get_digestbynid(NID_sha512WithRSAEncryption));
  EXPECT_EQ(nullptr, EVP_get_digestbynid(NID_undef));

  bssl::UniquePtr<ASN1_OBJECT> obj(OBJ_txt2obj("1.3.14.3.2.26", 0));
  ASSERT_TRUE(obj);
  EXPECT_EQ(EVP_sha1(), EVP_get_digestbyobj(obj.get()));
  EXPECT_EQ(EVP_md5_sha1(), EVP_get_digestbyobj(OBJ_nid2obj(NID_md5_sha1)));
  EXPECT_EQ(EVP_sha1(), EVP_get_digestbyobj(OBJ_nid2obj(NID_sha1)));
}

TEST(DigestTest, ASN1) {
  bssl::ScopedCBB cbb;
  ASSERT_TRUE(CBB_init(cbb.get(), 0));
  EXPECT_FALSE(EVP_marshal_digest_algorithm(cbb.get(), EVP_md5_sha1()));

  static const uint8_t kSHA256[] = {0x30, 0x0d, 0x06, 0x09, 0x60,
                                    0x86, 0x48, 0x01, 0x65, 0x03,
                                    0x04, 0x02, 0x01, 0x05, 0x00};
  static const uint8_t kSHA256NoParam[] = {0x30, 0x0b, 0x06, 0x09, 0x60,
                                           0x86, 0x48, 0x01, 0x65, 0x03,
                                           0x04, 0x02, 0x01};
  static const uint8_t kSHA256GarbageParam[] = {
      0x30, 0x0e, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01,
      0x65, 0x03, 0x04, 0x02, 0x01, 0x02, 0x01, 0x2a};

  // Serialize SHA-256.
  cbb.Reset();
  ASSERT_TRUE(CBB_init(cbb.get(), 0));
  ASSERT_TRUE(EVP_marshal_digest_algorithm(cbb.get(), EVP_sha256()));
  uint8_t *der;
  size_t der_len;
  ASSERT_TRUE(CBB_finish(cbb.get(), &der, &der_len));
  bssl::UniquePtr<uint8_t> free_der(der);
  EXPECT_EQ(Bytes(kSHA256), Bytes(der, der_len));

  // Parse SHA-256.
  CBS cbs;
  CBS_init(&cbs, kSHA256, sizeof(kSHA256));
  EXPECT_EQ(EVP_sha256(), EVP_parse_digest_algorithm(&cbs));
  EXPECT_EQ(0u, CBS_len(&cbs));

  // Missing parameters are tolerated for compatibility.
  CBS_init(&cbs, kSHA256NoParam, sizeof(kSHA256NoParam));
  EXPECT_EQ(EVP_sha256(), EVP_parse_digest_algorithm(&cbs));
  EXPECT_EQ(0u, CBS_len(&cbs));

  // Garbage parameters are not.
  CBS_init(&cbs, kSHA256GarbageParam, sizeof(kSHA256GarbageParam));
  EXPECT_FALSE(EVP_parse_digest_algorithm(&cbs));
}

TEST(DigestTest, TransformBlocks) {
  uint8_t blocks[SHA256_CBLOCK * 10];
  for (size_t i = 0; i < sizeof(blocks); i++) {
    blocks[i] = i*3;
  }

  SHA256_CTX ctx1;
  SHA256_Init(&ctx1);
  SHA256_Update(&ctx1, blocks, sizeof(blocks));

  SHA256_CTX ctx2;
  SHA256_Init(&ctx2);
  SHA256_TransformBlocks(ctx2.h, blocks, sizeof(blocks) / SHA256_CBLOCK);

  EXPECT_TRUE(0 == OPENSSL_memcmp(ctx1.h, ctx2.h, sizeof(ctx1.h)));
}