/* 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 <openssl/asn1.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"


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 md5_sha1 = { "MD5-SHA1", &EVP_md5_sha1, nullptr };

struct TestVector {
  // 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 TestVector 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" },

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

static bool CompareDigest(const TestVector *test,
                          const uint8_t *digest,
                          size_t digest_len) {
  static const char kHexTable[] = "0123456789abcdef";
  char digest_hex[2*EVP_MAX_MD_SIZE + 1];

  for (size_t i = 0; i < digest_len; i++) {
    digest_hex[2*i] = kHexTable[digest[i] >> 4];
    digest_hex[2*i + 1] = kHexTable[digest[i] & 0xf];
  }
  digest_hex[2*digest_len] = '\0';

  if (strcmp(digest_hex, test->expected_hex) != 0) {
    fprintf(stderr, "%s(\"%s\" * %d) = %s; want %s\n",
            test->md.name, test->input, (int)test->repeat,
            digest_hex, test->expected_hex);
    return false;
  }

  return true;
}

static int TestDigest(const TestVector *test) {
  bssl::ScopedEVP_MD_CTX ctx;

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

  // Test the input one character at a time.
  if (!EVP_DigestInit_ex(ctx.get(), test->md.func(), NULL)) {
    fprintf(stderr, "EVP_DigestInit_ex failed\n");
    return false;
  }
  if (!EVP_DigestUpdate(ctx.get(), NULL, 0)) {
    fprintf(stderr, "EVP_DigestUpdate failed\n");
    return false;
  }
  for (size_t i = 0; i < test->repeat; i++) {
    for (const char *p = test->input; *p; p++) {
      if (!EVP_DigestUpdate(ctx.get(), p, 1)) {
        fprintf(stderr, "EVP_DigestUpdate failed\n");
        return false;
      }
    }
  }
  if (!EVP_DigestFinal_ex(ctx.get(), digest.get(), &digest_len)) {
    fprintf(stderr, "EVP_DigestFinal_ex failed\n");
    return false;
  }
  if (digest_len != EVP_MD_size(test->md.func())) {
    fprintf(stderr, "EVP_MD_size output incorrect\n");
    return false;
  }
  if (!CompareDigest(test, digest.get(), digest_len)) {
    return false;
  }

  // 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());
    if (out != digest.get()) {
      fprintf(stderr, "one_shot_func gave incorrect return\n");
      return false;
    }
    if (!CompareDigest(test, digest.get(), EVP_MD_size(test->md.func()))) {
      return false;
    }

    // Test the deprecated static buffer variant, until it's removed.
    out = test->md.one_shot_func((const uint8_t *)test->input,
                                 strlen(test->input), NULL);
    if (!CompareDigest(test, out, EVP_MD_size(test->md.func()))) {
      return false;
    }
  }

  return true;
}

static int TestGetters() {
  if (EVP_get_digestbyname("RSA-SHA512") != EVP_sha512() ||
      EVP_get_digestbyname("sha512WithRSAEncryption") != EVP_sha512() ||
      EVP_get_digestbyname("nonsense") != NULL ||
      EVP_get_digestbyname("SHA512") != EVP_sha512() ||
      EVP_get_digestbyname("sha512") != EVP_sha512()) {
    return false;
  }

  if (EVP_get_digestbynid(NID_sha512) != EVP_sha512() ||
      EVP_get_digestbynid(NID_sha512WithRSAEncryption) != NULL ||
      EVP_get_digestbynid(NID_undef) != NULL) {
    return false;
  }

  bssl::UniquePtr<ASN1_OBJECT> obj(OBJ_txt2obj("1.3.14.3.2.26", 0));
  if (!obj ||
      EVP_get_digestbyobj(obj.get()) != EVP_sha1() ||
      EVP_get_digestbyobj(OBJ_nid2obj(NID_md5_sha1)) != EVP_md5_sha1() ||
      EVP_get_digestbyobj(OBJ_nid2obj(NID_sha1)) != EVP_sha1()) {
    return false;
  }

  return true;
}

int main() {
  CRYPTO_library_init();

  for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(kTestVectors); i++) {
    if (!TestDigest(&kTestVectors[i])) {
      fprintf(stderr, "Test %d failed\n", (int)i);
      return 1;
    }
  }

  if (!TestGetters()) {
    return 1;
  }

  printf("PASS\n");
  return 0;
}