xref: /PHP-8.3/ext/hash/hash_adler32.c (revision 2b8c0085)
1 /*
2   +----------------------------------------------------------------------+
3   | Copyright (c) The PHP Group                                          |
4   +----------------------------------------------------------------------+
5   | This source file is subject to version 3.01 of the PHP license,      |
6   | that is bundled with this package in the file LICENSE, and is        |
7   | available through the world-wide-web at the following url:           |
8   | https://www.php.net/license/3_01.txt                                 |
9   | If you did not receive a copy of the PHP license and are unable to   |
10   | obtain it through the world-wide-web, please send a note to          |
11   | license@php.net so we can mail you a copy immediately.               |
12   +----------------------------------------------------------------------+
13   | Authors: Michael Wallner <mike@php.net>                              |
14   |          Sara Golemon <pollita@php.net>                              |
15   +----------------------------------------------------------------------+
16 */
17 
18 #include "php_hash.h"
19 #include "php_hash_adler32.h"
20 
PHP_ADLER32Init(PHP_ADLER32_CTX * context,ZEND_ATTRIBUTE_UNUSED HashTable * args)21 PHP_HASH_API void PHP_ADLER32Init(PHP_ADLER32_CTX *context, ZEND_ATTRIBUTE_UNUSED HashTable *args)
22 {
23 	context->state = 1;
24 }
25 
PHP_ADLER32Update(PHP_ADLER32_CTX * context,const unsigned char * input,size_t len)26 PHP_HASH_API void PHP_ADLER32Update(PHP_ADLER32_CTX *context, const unsigned char *input, size_t len)
27 {
28 	uint32_t s[2];
29 
30 	s[0] = context->state & 0xffff;
31 	s[1] = (context->state >> 16) & 0xffff;
32 	for (size_t i = 0; i < len; ++i) {
33 		s[0] += input[i];
34 		s[1] += s[0];
35 		if (s[1]>=0x7fffffff)
36 		{
37 			s[0] = s[0] % 65521;
38 			s[1] = s[1] % 65521;
39 		}
40 	}
41 	s[0] = s[0] % 65521;
42 	s[1] = s[1] % 65521;
43 	context->state = s[0] + (s[1] << 16);
44 }
45 
PHP_ADLER32Final(unsigned char digest[4],PHP_ADLER32_CTX * context)46 PHP_HASH_API void PHP_ADLER32Final(unsigned char digest[4], PHP_ADLER32_CTX *context)
47 {
48 	digest[0] = (unsigned char) ((context->state >> 24) & 0xff);
49 	digest[1] = (unsigned char) ((context->state >> 16) & 0xff);
50 	digest[2] = (unsigned char) ((context->state >> 8) & 0xff);
51 	digest[3] = (unsigned char) (context->state & 0xff);
52 	context->state = 0;
53 }
54 
PHP_ADLER32Copy(const php_hash_ops * ops,PHP_ADLER32_CTX * orig_context,PHP_ADLER32_CTX * copy_context)55 PHP_HASH_API int PHP_ADLER32Copy(const php_hash_ops *ops, PHP_ADLER32_CTX *orig_context, PHP_ADLER32_CTX *copy_context)
56 {
57 	copy_context->state = orig_context->state;
58 	return SUCCESS;
59 }
60 
61 const php_hash_ops php_hash_adler32_ops = {
62 	"adler32",
63 	(php_hash_init_func_t) PHP_ADLER32Init,
64 	(php_hash_update_func_t) PHP_ADLER32Update,
65 	(php_hash_final_func_t) PHP_ADLER32Final,
66 	(php_hash_copy_func_t) PHP_ADLER32Copy,
67 	php_hash_serialize,
68 	php_hash_unserialize,
69 	PHP_ADLER32_SPEC,
70 	4, /* what to say here? */
71 	4,
72 	sizeof(PHP_ADLER32_CTX),
73 	0
74 };
75