/** @file

  Generic wrapper for cryptographic hashes.

  @section license License

  Licensed to the Apache Software Foundation (ASF) under one

  or more contributor license agreements.  See the NOTICE file

  distributed with this work for additional information

  regarding copyright ownership.  The ASF licenses this file

  to you 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

      http://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 <cstdlib>

#include <cstring>

#include <new>

#include "tscore/ink_assert.h"

#include "tscore/ink_platform.h"

#include "tscore/CryptoHash.h"

#include "tscore/SHA256.h"

#if TS_ENABLE_FIPS == 1

CryptoContext::HashType CryptoContext::Setting = CryptoContext::SHA256;

#else

#include "tscore/MD5.h"

#include "tscore/MMH.h"

CryptoContext::HashType CryptoContext::Setting = CryptoContext::MD5;

#endif

CryptoContext::CryptoContext()

{

  switch (Setting) {

  case UNSPECIFIED:

#if TS_ENABLE_FIPS == 0

  case MD5:

    static_assert(OBJ_SIZE >= sizeof(MD5Context));

    new (_base) MD5Context;

    break;

#else

  case SHA256:

    static_assert(OBJ_SIZE >= sizeof(SHA256Context));

    new (_base) SHA256Context;

    break;

#endif

  default:

    ink_release_assert(!"Invalid global URL hash context");

  };

}

/**

  @brief Converts a hash to a null-terminated string

  Externalizes an hash as a null-terminated string into the first argument.

  Does so without internal procedure calls.

  Side Effects: none.

  Reentrancy:     n/a.

  Thread Safety:  safe.

  Mem Management: stomps the passed dest char*.

  @return returns the passed destination string ptr.

*/

/* reentrant version */

static char *

ink_code_to_hex_str(char *dest, uint8_t const *hash)

{

  int   i;

  char *d;

  static char hex_digits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

  d = dest;

  for (i = 0; i < CRYPTO_HASH_SIZE; i += 4) {

    *(d + 0)  = hex_digits[hash[i + 0] >> 4];

    *(d + 1)  = hex_digits[hash[i + 0] & 15];

    *(d + 2)  = hex_digits[hash[i + 1] >> 4];

    *(d + 3)  = hex_digits[hash[i + 1] & 15];

    *(d + 4)  = hex_digits[hash[i + 2] >> 4];

    *(d + 5)  = hex_digits[hash[i + 2] & 15];

    *(d + 6)  = hex_digits[hash[i + 3] >> 4];

    *(d + 7)  = hex_digits[hash[i + 3] & 15];

    d        += 8;

  }

  *d = '\0';

  return (dest);

}

char *

CryptoHash::toHexStr(char buffer[(CRYPTO_HASH_SIZE * 2) + 1]) const

{

  return ink_code_to_hex_str(buffer, u8);

}

namespace ts

{

swoc::BufferWriter &

bwformat(swoc::BufferWriter &w, swoc::bwf::Spec const &spec, ts::CryptoHash const &hash)

{

  swoc::bwf::Spec local_spec{spec};

  if ('X' != local_spec._type) {

    local_spec._type = 'x';

  }

  return bwformat(w, local_spec, std::string_view(reinterpret_cast<const char *>(hash.u8), CRYPTO_HASH_SIZE));

}

} // namespace ts