xref: /PHP-7.3/ext/hash/hash_adler32.c (revision 8d3f8ca1)
1 /*
2   +----------------------------------------------------------------------+
3   | PHP Version 7                                                        |
4   +----------------------------------------------------------------------+
5   | Copyright (c) 1997-2018 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 #include "php_hash.h"
21 #include "php_hash_adler32.h"
22 
PHP_ADLER32Init(PHP_ADLER32_CTX * context)23 PHP_HASH_API void PHP_ADLER32Init(PHP_ADLER32_CTX *context)
24 {
25 	context->state = 1;
26 }
27 
PHP_ADLER32Update(PHP_ADLER32_CTX * context,const unsigned char * input,size_t len)28 PHP_HASH_API void PHP_ADLER32Update(PHP_ADLER32_CTX *context, const unsigned char *input, size_t len)
29 {
30 	uint32_t i, s[2];
31 
32 	s[0] = context->state & 0xffff;
33 	s[1] = (context->state >> 16) & 0xffff;
34 	for (i = 0; i < len; ++i) {
35 		s[0] += input[i];
36 		s[1] += s[0];
37 		if (s[1]>=0x7fffffff)
38 		{
39 			s[0] = s[0] % 65521;
40 			s[1] = s[1] % 65521;
41 		}
42 	}
43 	s[0] = s[0] % 65521;
44 	s[1] = s[1] % 65521;
45 	context->state = s[0] + (s[1] << 16);
46 }
47 
PHP_ADLER32Final(unsigned char digest[4],PHP_ADLER32_CTX * context)48 PHP_HASH_API void PHP_ADLER32Final(unsigned char digest[4], PHP_ADLER32_CTX *context)
49 {
50 	digest[0] = (unsigned char) ((context->state >> 24) & 0xff);
51 	digest[1] = (unsigned char) ((context->state >> 16) & 0xff);
52 	digest[2] = (unsigned char) ((context->state >> 8) & 0xff);
53 	digest[3] = (unsigned char) (context->state & 0xff);
54 	context->state = 0;
55 }
56 
PHP_ADLER32Copy(const php_hash_ops * ops,PHP_ADLER32_CTX * orig_context,PHP_ADLER32_CTX * copy_context)57 PHP_HASH_API int PHP_ADLER32Copy(const php_hash_ops *ops, PHP_ADLER32_CTX *orig_context, PHP_ADLER32_CTX *copy_context)
58 {
59 	copy_context->state = orig_context->state;
60 	return SUCCESS;
61 }
62 
63 const php_hash_ops php_hash_adler32_ops = {
64 	(php_hash_init_func_t) PHP_ADLER32Init,
65 	(php_hash_update_func_t) PHP_ADLER32Update,
66 	(php_hash_final_func_t) PHP_ADLER32Final,
67 	(php_hash_copy_func_t) PHP_ADLER32Copy,
68 	4, /* what to say here? */
69 	4,
70 	sizeof(PHP_ADLER32_CTX),
71 	0
72 };
73 
74 /*
75  * Local variables:
76  * tab-width: 4
77  * c-basic-offset: 4
78  * End:
79  * vim600: sw=4 ts=4 fdm=marker
80  * vim<600: sw=4 ts=4
81  */
82