/*

  +----------------------------------------------------------------------+

  | Copyright © The PHP Group and Contributors.                          |

  +----------------------------------------------------------------------+

  | This source file is subject to the Modified BSD License that is      |

  | bundled with this package in the file LICENSE, and is available      |

  | through the World Wide Web at <https://www.php.net/license/>.        |

  |                                                                      |

  | SPDX-License-Identifier: BSD-3-Clause                                |

  +----------------------------------------------------------------------+

  | Authors: Michael Wallner <mike@php.net>                              |

  |          Sara Golemon <pollita@php.net>                              |

  +----------------------------------------------------------------------+

*/

#include "php_hash.h"

#include "php_hash_adler32.h"

PHP_HASH_API void PHP_ADLER32Init(PHP_ADLER32_CTX *context, ZEND_ATTRIBUTE_UNUSED HashTable *args)

{

  context->state = 1;

}

PHP_HASH_API void PHP_ADLER32Update(PHP_ADLER32_CTX *context, const unsigned char *input, size_t len)

{

  uint32_t s[2];

  s[0] = context->state & 0xffff;

  s[1] = (context->state >> 16) & 0xffff;

  for (size_t i = 0; i < len; ++i) {

    s[0] += input[i];

    s[1] += s[0];

    if (s[1]>=0x7fffffff)

    {

      s[0] = s[0] % 65521;

      s[1] = s[1] % 65521;

    }

  }

  s[0] = s[0] % 65521;

  s[1] = s[1] % 65521;

  context->state = s[0] + (s[1] << 16);

}

PHP_HASH_API void PHP_ADLER32Final(unsigned char digest[4], PHP_ADLER32_CTX *context)

{

  digest[0] = (unsigned char) ((context->state >> 24) & 0xff);

  digest[1] = (unsigned char) ((context->state >> 16) & 0xff);

  digest[2] = (unsigned char) ((context->state >> 8) & 0xff);

  digest[3] = (unsigned char) (context->state & 0xff);

  context->state = 0;

}

PHP_HASH_API zend_result PHP_ADLER32Copy(const php_hash_ops *ops, const PHP_ADLER32_CTX *orig_context, PHP_ADLER32_CTX *copy_context)

{

  copy_context->state = orig_context->state;

  return SUCCESS;

}

const php_hash_ops php_hash_adler32_ops = {

  "adler32",

  (php_hash_init_func_t) PHP_ADLER32Init,

  (php_hash_update_func_t) PHP_ADLER32Update,

  (php_hash_final_func_t) PHP_ADLER32Final,

  (php_hash_copy_func_t) PHP_ADLER32Copy,

  php_hash_serialize,

  php_hash_unserialize,

  PHP_ADLER32_SPEC,

  4, /* what to say here? */

  4,

  sizeof(PHP_ADLER32_CTX),

  0

};