/*

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

  | 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                                |

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

  | Author: Martin Jansen <mj@php.net>                                   |

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

*/

/* Implements Jenkins's one-at-a-time hashing algorithm as presented on

 * http://www.burtleburtle.net/bob/hash/doobs.html.

 */

#include "php_hash.h"

#include "php_hash_joaat.h"

const php_hash_ops php_hash_joaat_ops = {

  "joaat",

  (php_hash_init_func_t) PHP_JOAATInit,

  (php_hash_update_func_t) PHP_JOAATUpdate,

  (php_hash_final_func_t) PHP_JOAATFinal,

  php_hash_copy,

  php_hash_serialize,

  php_hash_unserialize,

  PHP_JOAAT_SPEC,

  4,

  4,

  sizeof(PHP_JOAAT_CTX),

  0,

  0

};

PHP_HASH_API void PHP_JOAATInit(PHP_JOAAT_CTX *context, ZEND_ATTRIBUTE_UNUSED HashTable *args)

{

  context->state = 0;

}

PHP_HASH_API void PHP_JOAATUpdate(PHP_JOAAT_CTX *context, const unsigned char *input, size_t inputLen)

{

  context->state = joaat_buf((void *)input, inputLen, context->state);

}

PHP_HASH_API void PHP_JOAATFinal(unsigned char digest[4], PHP_JOAAT_CTX * context)

{

  uint32_t hval = context->state;

  hval += (hval << 3);

  hval ^= (hval >> 11);

  hval += (hval << 15);

#ifdef WORDS_BIGENDIAN

  memcpy(digest, &hval, 4);

#else

  int i = 0;

  unsigned char *c = (unsigned char *) &hval;

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

    digest[i] = c[3 - i];

  }

#endif

  context->state = 0;

}

/*

 * joaat_buf - perform a Jenkins's one-at-a-time hash on a buffer

 *

 * input:

 *  buf - start of buffer to hash

 *  len - length of buffer in octets

 *

 * returns:

 *  32 bit hash as a static hash type

 */

static uint32_t

joaat_buf(void *buf, size_t len, uint32_t hval)

{

  size_t i;

  unsigned char *input = (unsigned char *)buf;

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

    hval += input[i];

    hval += (hval << 10);

    hval ^= (hval >> 6);

  }

  return hval;

}