hash_adler32.c 2.7 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182
  1. /*
  2. +----------------------------------------------------------------------+
  3. | PHP Version 5 |
  4. +----------------------------------------------------------------------+
  5. | Copyright (c) 1997-2016 The PHP Group |
  6. +----------------------------------------------------------------------+
  7. | This source file is subject to version 3.01 of the PHP license, |
  8. | that is bundled with this package in the file LICENSE, and is |
  9. | available through the world-wide-web at the following url: |
  10. | http://www.php.net/license/3_01.txt |
  11. | If you did not receive a copy of the PHP license and are unable to |
  12. | obtain it through the world-wide-web, please send a note to |
  13. | license@php.net so we can mail you a copy immediately. |
  14. +----------------------------------------------------------------------+
  15. | Authors: Michael Wallner <mike@php.net> |
  16. | Sara Golemon <pollita@php.net> |
  17. +----------------------------------------------------------------------+
  18. */
  19. /* $Id$ */
  20. #include "php_hash.h"
  21. #include "php_hash_adler32.h"
  22. PHP_HASH_API void PHP_ADLER32Init(PHP_ADLER32_CTX *context)
  23. {
  24. context->state = 1;
  25. }
  26. PHP_HASH_API void PHP_ADLER32Update(PHP_ADLER32_CTX *context, const unsigned char *input, size_t len)
  27. {
  28. php_hash_uint32 i, s[2];
  29. s[0] = context->state & 0xffff;
  30. s[1] = (context->state >> 16) & 0xffff;
  31. for (i = 0; i < len; ++i) {
  32. s[0] += input[i];
  33. s[1] += s[0];
  34. if (s[1]>=0x7fffffff)
  35. {
  36. s[0] = s[0] % 65521;
  37. s[1] = s[1] % 65521;
  38. }
  39. }
  40. s[0] = s[0] % 65521;
  41. s[1] = s[1] % 65521;
  42. context->state = s[0] + (s[1] << 16);
  43. }
  44. PHP_HASH_API void PHP_ADLER32Final(unsigned char digest[4], PHP_ADLER32_CTX *context)
  45. {
  46. digest[0] = (unsigned char) ((context->state >> 24) & 0xff);
  47. digest[1] = (unsigned char) ((context->state >> 16) & 0xff);
  48. digest[2] = (unsigned char) ((context->state >> 8) & 0xff);
  49. digest[3] = (unsigned char) (context->state & 0xff);
  50. context->state = 0;
  51. }
  52. PHP_HASH_API int PHP_ADLER32Copy(const php_hash_ops *ops, PHP_ADLER32_CTX *orig_context, PHP_ADLER32_CTX *copy_context)
  53. {
  54. copy_context->state = orig_context->state;
  55. return SUCCESS;
  56. }
  57. const php_hash_ops php_hash_adler32_ops = {
  58. (php_hash_init_func_t) PHP_ADLER32Init,
  59. (php_hash_update_func_t) PHP_ADLER32Update,
  60. (php_hash_final_func_t) PHP_ADLER32Final,
  61. (php_hash_copy_func_t) PHP_ADLER32Copy,
  62. 4, /* what to say here? */
  63. 4,
  64. sizeof(PHP_ADLER32_CTX)
  65. };
  66. /*
  67. * Local variables:
  68. * tab-width: 4
  69. * c-basic-offset: 4
  70. * End:
  71. * vim600: sw=4 ts=4 fdm=marker
  72. * vim<600: sw=4 ts=4
  73. */