xref: /PHP-5.3/ext/hash/hash_crc32.c (revision a2045ff3)
1 /*
2   +----------------------------------------------------------------------+
3   | PHP Version 5                                                        |
4   +----------------------------------------------------------------------+
5   | Copyright (c) 1997-2013 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_crc32.h"
24 #include "php_hash_crc32_tables.h"
25 
PHP_CRC32Init(PHP_CRC32_CTX * context)26 PHP_HASH_API void PHP_CRC32Init(PHP_CRC32_CTX *context)
27 {
28 	context->state = ~0;
29 }
30 
PHP_CRC32Update(PHP_CRC32_CTX * context,const unsigned char * input,size_t len)31 PHP_HASH_API void PHP_CRC32Update(PHP_CRC32_CTX *context, const unsigned char *input, size_t len)
32 {
33 	size_t i;
34 
35 	for (i = 0; i < len; ++i) {
36 		context->state = (context->state << 8) ^ crc32_table[(context->state >> 24) ^ (input[i] & 0xff)];
37 	}
38 }
39 
PHP_CRC32BUpdate(PHP_CRC32_CTX * context,const unsigned char * input,size_t len)40 PHP_HASH_API void PHP_CRC32BUpdate(PHP_CRC32_CTX *context, const unsigned char *input, size_t len)
41 {
42 	size_t i;
43 
44 	for (i = 0; i < len; ++i) {
45 		context->state = (context->state >> 8) ^ crc32b_table[(context->state ^ input[i]) & 0xff];
46 	}
47 }
48 
PHP_CRC32Final(unsigned char digest[4],PHP_CRC32_CTX * context)49 PHP_HASH_API void PHP_CRC32Final(unsigned char digest[4], PHP_CRC32_CTX *context)
50 {
51 	context->state=~context->state;
52 	digest[3] = (unsigned char) ((context->state >> 24) & 0xff);
53 	digest[2] = (unsigned char) ((context->state >> 16) & 0xff);
54 	digest[1] = (unsigned char) ((context->state >> 8) & 0xff);
55 	digest[0] = (unsigned char) (context->state & 0xff);
56 	context->state = 0;
57 }
58 
PHP_CRC32BFinal(unsigned char digest[4],PHP_CRC32_CTX * context)59 PHP_HASH_API void PHP_CRC32BFinal(unsigned char digest[4], PHP_CRC32_CTX *context)
60 {
61 	context->state=~context->state;
62 	digest[0] = (unsigned char) ((context->state >> 24) & 0xff);
63 	digest[1] = (unsigned char) ((context->state >> 16) & 0xff);
64 	digest[2] = (unsigned char) ((context->state >> 8) & 0xff);
65 	digest[3] = (unsigned char) (context->state & 0xff);
66 	context->state = 0;
67 }
68 
PHP_CRC32Copy(const php_hash_ops * ops,PHP_CRC32_CTX * orig_context,PHP_CRC32_CTX * copy_context)69 PHP_HASH_API int PHP_CRC32Copy(const php_hash_ops *ops, PHP_CRC32_CTX *orig_context, PHP_CRC32_CTX *copy_context)
70 {
71 	copy_context->state = orig_context->state;
72 	return SUCCESS;
73 }
74 
75 const php_hash_ops php_hash_crc32_ops = {
76 	(php_hash_init_func_t) PHP_CRC32Init,
77 	(php_hash_update_func_t) PHP_CRC32Update,
78 	(php_hash_final_func_t) PHP_CRC32Final,
79 	(php_hash_copy_func_t) PHP_CRC32Copy,
80 	4, /* what to say here? */
81 	4,
82 	sizeof(PHP_CRC32_CTX)
83 };
84 
85 const php_hash_ops php_hash_crc32b_ops = {
86 	(php_hash_init_func_t) PHP_CRC32Init,
87 	(php_hash_update_func_t) PHP_CRC32BUpdate,
88 	(php_hash_final_func_t) PHP_CRC32BFinal,
89 	(php_hash_copy_func_t) PHP_CRC32Copy,
90 	4, /* what to say here? */
91 	4,
92 	sizeof(PHP_CRC32_CTX)
93 };
94 
95 /*
96  * Local variables:
97  * tab-width: 4
98  * c-basic-offset: 4
99  * End:
100  * vim600: sw=4 ts=4 fdm=marker
101  * vim<600: sw=4 ts=4
102  */
103