xref: /PHP-5.5/ext/hash/hash_joaat.c (revision 73c1be26)
1 /*
2   +----------------------------------------------------------------------+
3   | PHP Version 5                                                        |
4   +----------------------------------------------------------------------+
5   | Copyright (c) 1997-2015 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   | Author: Martin Jansen <mj@php.net>                                   |
16   +----------------------------------------------------------------------+
17 */
18 
19 /* $Id$ */
20 
21 /* Implements Jenkins's one-at-a-time hashing algorithm as presented on
22  * http://www.burtleburtle.net/bob/hash/doobs.html.
23  */
24 
25 #include "php_hash.h"
26 #include "php_hash_joaat.h"
27 
28 const php_hash_ops php_hash_joaat_ops = {
29 	(php_hash_init_func_t) PHP_JOAATInit,
30 	(php_hash_update_func_t) PHP_JOAATUpdate,
31 	(php_hash_final_func_t) PHP_JOAATFinal,
32 	(php_hash_copy_func_t) php_hash_copy,
33 	4,
34 	4,
35 	sizeof(PHP_JOAAT_CTX)
36 };
37 
PHP_JOAATInit(PHP_JOAAT_CTX * context)38 PHP_HASH_API void PHP_JOAATInit(PHP_JOAAT_CTX *context)
39 {
40 	context->state = 0;
41 }
42 
PHP_JOAATUpdate(PHP_JOAAT_CTX * context,const unsigned char * input,unsigned int inputLen)43 PHP_HASH_API void PHP_JOAATUpdate(PHP_JOAAT_CTX *context, const unsigned char *input, unsigned int inputLen)
44 {
45 	context->state = joaat_buf((void *)input, inputLen, context->state);
46 }
47 
PHP_JOAATFinal(unsigned char digest[4],PHP_JOAAT_CTX * context)48 PHP_HASH_API void PHP_JOAATFinal(unsigned char digest[4], PHP_JOAAT_CTX * context)
49 {
50 #ifdef WORDS_BIGENDIAN
51 	memcpy(digest, &context->state, 4);
52 #else
53 	int i = 0;
54 	unsigned char *c = (unsigned char *) &context->state;
55 
56 	for (i = 0; i < 4; i++) {
57 		digest[i] = c[3 - i];
58 	}
59 #endif
60     context->state = 0;
61 }
62 
63 /*
64  * joaat_buf - perform a Jenkins's one-at-a-time hash on a buffer
65  *
66  * input:
67  *  buf - start of buffer to hash
68  *  len - length of buffer in octets
69  *
70  * returns:
71  *  32 bit hash as a static hash type
72  */
73 static php_hash_uint32
joaat_buf(void * buf,size_t len,php_hash_uint32 hval)74 joaat_buf(void *buf, size_t len, php_hash_uint32 hval)
75 {
76     size_t i;
77     unsigned char *input = (unsigned char *)buf;
78 
79     for (i = 0; i < len; i++) {
80         hval += input[i];
81         hval += (hval << 10);
82         hval ^= (hval >> 6);
83     }
84 
85     hval += (hval << 3);
86     hval ^= (hval >> 11);
87     hval += (hval << 15);
88 
89     return hval;
90 }
91 
92 /*
93  * Local variables:
94  * tab-width: 4
95  * c-basic-offset: 4
96  * End:
97  * vim600: noet sw=4 ts=4 fdm=marker
98  * vim<600: noet sw=4 ts=4
99  */
100