1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* RFC2104 Keyed-Hashing for Message Authentication
*
***************************************************************************/
#include "curl_setup.h"
#ifndef CURL_DISABLE_CRYPTO_AUTH
#include "curl_hmac.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"
/*
* Generic HMAC algorithm.
*
* This module computes HMAC digests based on any hash function. Parameters
* and computing procedures are set-up dynamically at HMAC computation
* context initialisation.
*/
static const unsigned char hmac_ipad = 0x36;
static const unsigned char hmac_opad = 0x5C;
HMAC_context *
Curl_HMAC_init(const HMAC_params * hashparams,
const unsigned char * key,
unsigned int keylen)
{
size_t i;
HMAC_context * ctxt;
unsigned char * hkey;
unsigned char b;
/* Create HMAC context. */
i = sizeof *ctxt + 2 * hashparams->hmac_ctxtsize +
hashparams->hmac_resultlen;
ctxt = malloc(i);
if(!ctxt)
return ctxt;
ctxt->hmac_hash = hashparams;
ctxt->hmac_hashctxt1 = (void *) (ctxt + 1);
ctxt->hmac_hashctxt2 = (void *) ((char *) ctxt->hmac_hashctxt1 +
hashparams->hmac_ctxtsize);
/* If the key is too long, replace it by its hash digest. */
if(keylen > hashparams->hmac_maxkeylen) {
(*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, key, keylen);
hkey = (unsigned char *) ctxt->hmac_hashctxt2 + hashparams->hmac_ctxtsize;
(*hashparams->hmac_hfinal)(hkey, ctxt->hmac_hashctxt1);
key = hkey;
keylen = hashparams->hmac_resultlen;
}
/* Prime the two hash contexts with the modified key. */
(*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
(*hashparams->hmac_hinit)(ctxt->hmac_hashctxt2);
for(i = 0; i < keylen; i++) {
b = (unsigned char)(*key ^ hmac_ipad);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &b, 1);
b = (unsigned char)(*key++ ^ hmac_opad);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &b, 1);
}
for(; i < hashparams->hmac_maxkeylen; i++) {
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &hmac_ipad, 1);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &hmac_opad, 1);
}
/* Done, return pointer to HMAC context. */
return ctxt;
}
int Curl_HMAC_update(HMAC_context * ctxt,
const unsigned char * data,
unsigned int len)
{
/* Update first hash calculation. */
(*ctxt->hmac_hash->hmac_hupdate)(ctxt->hmac_hashctxt1, data, len);
return 0;
}
int Curl_HMAC_final(HMAC_context * ctxt, unsigned char * result)
{
const HMAC_params * hashparams = ctxt->hmac_hash;
/* Do not get result if called with a null parameter: only release
storage. */
if(!result)
result = (unsigned char *) ctxt->hmac_hashctxt2 +
ctxt->hmac_hash->hmac_ctxtsize;
(*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt1);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2,
result, hashparams->hmac_resultlen);
(*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt2);
free((char *) ctxt);
return 0;
}
#endif /* CURL_DISABLE_CRYPTO_AUTH */
|
