xref: /PHP-5.4/ext/hash/hash_adler32.c (revision c0d060f5)
1 /*
2   +----------------------------------------------------------------------+
3   | PHP Version 5                                                        |
4   +----------------------------------------------------------------------+
5   | Copyright (c) 1997-2014 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 
20 /* $Id$ */
21 
22 #include "php_hash.h"
23 #include "php_hash_adler32.h"
24 
PHP_ADLER32Init(PHP_ADLER32_CTX * context)25 PHP_HASH_API void PHP_ADLER32Init(PHP_ADLER32_CTX *context)
26 {
27 	context->state = 1;
28 }
29 
PHP_ADLER32Update(PHP_ADLER32_CTX * context,const unsigned char * input,size_t len)30 PHP_HASH_API void PHP_ADLER32Update(PHP_ADLER32_CTX *context, const unsigned char *input, size_t len)
31 {
32 	php_hash_uint32 i, s[2];
33 
34 	s[0] = context->state & 0xffff;
35 	s[1] = (context->state >> 16) & 0xffff;
36 	for (i = 0; i < len; ++i) {
37 		s[0] += input[i];
38 		s[1] += s[0];
39 		if (s[1]>=0x7fffffff)
40 		{
41 			s[0] = s[0] % 65521;
42 			s[1] = s[1] % 65521;
43 		}
44 	}
45 	s[0] = s[0] % 65521;
46 	s[1] = s[1] % 65521;
47 	context->state = s[0] + (s[1] << 16);
48 }
49 
PHP_ADLER32Final(unsigned char digest[4],PHP_ADLER32_CTX * context)50 PHP_HASH_API void PHP_ADLER32Final(unsigned char digest[4], PHP_ADLER32_CTX *context)
51 {
52 	digest[0] = (unsigned char) ((context->state >> 24) & 0xff);
53 	digest[1] = (unsigned char) ((context->state >> 16) & 0xff);
54 	digest[2] = (unsigned char) ((context->state >> 8) & 0xff);
55 	digest[3] = (unsigned char) (context->state & 0xff);
56 	context->state = 0;
57 }
58 
PHP_ADLER32Copy(const php_hash_ops * ops,PHP_ADLER32_CTX * orig_context,PHP_ADLER32_CTX * copy_context)59 PHP_HASH_API int PHP_ADLER32Copy(const php_hash_ops *ops, PHP_ADLER32_CTX *orig_context, PHP_ADLER32_CTX *copy_context)
60 {
61 	copy_context->state = orig_context->state;
62 	return SUCCESS;
63 }
64 
65 const php_hash_ops php_hash_adler32_ops = {
66 	(php_hash_init_func_t) PHP_ADLER32Init,
67 	(php_hash_update_func_t) PHP_ADLER32Update,
68 	(php_hash_final_func_t) PHP_ADLER32Final,
69 	(php_hash_copy_func_t) PHP_ADLER32Copy,
70 	4, /* what to say here? */
71 	4,
72 	sizeof(PHP_ADLER32_CTX)
73 };
74 
75 /*
76  * Local variables:
77  * tab-width: 4
78  * c-basic-offset: 4
79  * End:
80  * vim600: sw=4 ts=4 fdm=marker
81  * vim<600: sw=4 ts=4
82  */
83