1 /* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5 #ifdef FREEBL_NO_DEPEND
6 #include "stubs.h"
7 #endif
8
9 #include "secport.h"
10 #include "hasht.h"
11 #include "blapit.h"
12 #include "alghmac.h"
13 #include "secerr.h"
14
15 #define HMAC_PAD_SIZE HASH_BLOCK_LENGTH_MAX
16
17 struct HMACContextStr {
18 void *hash;
19 const SECHashObject *hashobj;
20 PRBool wasAllocated;
21 unsigned char ipad[HMAC_PAD_SIZE];
22 unsigned char opad[HMAC_PAD_SIZE];
23 };
24
25 void
HMAC_Destroy(HMACContext * cx,PRBool freeit)26 HMAC_Destroy(HMACContext *cx, PRBool freeit)
27 {
28 if (cx == NULL)
29 return;
30
31 PORT_Assert(!freeit == !cx->wasAllocated);
32 if (cx->hash != NULL) {
33 cx->hashobj->destroy(cx->hash, PR_TRUE);
34 PORT_Memset(cx, 0, sizeof *cx);
35 }
36 if (freeit)
37 PORT_Free(cx);
38 }
39
40 SECStatus
HMAC_Init(HMACContext * cx,const SECHashObject * hash_obj,const unsigned char * secret,unsigned int secret_len,PRBool isFIPS)41 HMAC_Init(HMACContext *cx, const SECHashObject *hash_obj,
42 const unsigned char *secret, unsigned int secret_len, PRBool isFIPS)
43 {
44 unsigned int i;
45 unsigned char hashed_secret[HASH_LENGTH_MAX];
46
47 /* required by FIPS 198 Section 3 */
48 if (isFIPS && secret_len < hash_obj->length / 2) {
49 PORT_SetError(SEC_ERROR_INVALID_ARGS);
50 return SECFailure;
51 }
52 if (cx == NULL) {
53 PORT_SetError(SEC_ERROR_INVALID_ARGS);
54 return SECFailure;
55 }
56 cx->wasAllocated = PR_FALSE;
57 cx->hashobj = hash_obj;
58 cx->hash = cx->hashobj->create();
59 if (cx->hash == NULL)
60 goto loser;
61
62 if (secret_len > cx->hashobj->blocklength) {
63 cx->hashobj->begin(cx->hash);
64 cx->hashobj->update(cx->hash, secret, secret_len);
65 PORT_Assert(cx->hashobj->length <= sizeof hashed_secret);
66 cx->hashobj->end(cx->hash, hashed_secret, &secret_len,
67 sizeof hashed_secret);
68 if (secret_len != cx->hashobj->length) {
69 PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
70 goto loser;
71 }
72 secret = (const unsigned char *)&hashed_secret[0];
73 }
74
75 PORT_Memset(cx->ipad, 0x36, cx->hashobj->blocklength);
76 PORT_Memset(cx->opad, 0x5c, cx->hashobj->blocklength);
77
78 /* fold secret into padding */
79 for (i = 0; i < secret_len; i++) {
80 cx->ipad[i] ^= secret[i];
81 cx->opad[i] ^= secret[i];
82 }
83 PORT_Memset(hashed_secret, 0, sizeof hashed_secret);
84 return SECSuccess;
85
86 loser:
87 PORT_Memset(hashed_secret, 0, sizeof hashed_secret);
88 if (cx->hash != NULL)
89 cx->hashobj->destroy(cx->hash, PR_TRUE);
90 return SECFailure;
91 }
92
93 HMACContext *
HMAC_Create(const SECHashObject * hash_obj,const unsigned char * secret,unsigned int secret_len,PRBool isFIPS)94 HMAC_Create(const SECHashObject *hash_obj, const unsigned char *secret,
95 unsigned int secret_len, PRBool isFIPS)
96 {
97 SECStatus rv;
98 HMACContext *cx = PORT_ZNew(HMACContext);
99 if (cx == NULL)
100 return NULL;
101 rv = HMAC_Init(cx, hash_obj, secret, secret_len, isFIPS);
102 cx->wasAllocated = PR_TRUE;
103 if (rv != SECSuccess) {
104 PORT_Free(cx); /* contains no secret info */
105 cx = NULL;
106 }
107 return cx;
108 }
109
110 void
HMAC_Begin(HMACContext * cx)111 HMAC_Begin(HMACContext *cx)
112 {
113 /* start inner hash */
114 cx->hashobj->begin(cx->hash);
115 cx->hashobj->update(cx->hash, cx->ipad, cx->hashobj->blocklength);
116 }
117
118 void
HMAC_Update(HMACContext * cx,const unsigned char * data,unsigned int data_len)119 HMAC_Update(HMACContext *cx, const unsigned char *data, unsigned int data_len)
120 {
121 cx->hashobj->update(cx->hash, data, data_len);
122 }
123
124 SECStatus
HMAC_Finish(HMACContext * cx,unsigned char * result,unsigned int * result_len,unsigned int max_result_len)125 HMAC_Finish(HMACContext *cx, unsigned char *result, unsigned int *result_len,
126 unsigned int max_result_len)
127 {
128 if (max_result_len < cx->hashobj->length) {
129 PORT_SetError(SEC_ERROR_INVALID_ARGS);
130 return SECFailure;
131 }
132
133 cx->hashobj->end(cx->hash, result, result_len, max_result_len);
134 if (*result_len != cx->hashobj->length)
135 return SECFailure;
136
137 cx->hashobj->begin(cx->hash);
138 cx->hashobj->update(cx->hash, cx->opad, cx->hashobj->blocklength);
139 cx->hashobj->update(cx->hash, result, *result_len);
140 cx->hashobj->end(cx->hash, result, result_len, max_result_len);
141 return SECSuccess;
142 }
143
144 HMACContext *
HMAC_Clone(HMACContext * cx)145 HMAC_Clone(HMACContext *cx)
146 {
147 HMACContext *newcx;
148
149 newcx = (HMACContext *)PORT_ZAlloc(sizeof(HMACContext));
150 if (newcx == NULL)
151 goto loser;
152
153 newcx->wasAllocated = PR_TRUE;
154 newcx->hashobj = cx->hashobj;
155 newcx->hash = cx->hashobj->clone(cx->hash);
156 if (newcx->hash == NULL)
157 goto loser;
158 PORT_Memcpy(newcx->ipad, cx->ipad, cx->hashobj->blocklength);
159 PORT_Memcpy(newcx->opad, cx->opad, cx->hashobj->blocklength);
160 return newcx;
161
162 loser:
163 HMAC_Destroy(newcx, PR_TRUE);
164 return NULL;
165 }
166