Line data Source code
1 : /*
2 : * px-hmac.c
3 : * HMAC implementation.
4 : *
5 : * Copyright (c) 2001 Marko Kreen
6 : * All rights reserved.
7 : *
8 : * Redistribution and use in source and binary forms, with or without
9 : * modification, are permitted provided that the following conditions
10 : * are met:
11 : * 1. Redistributions of source code must retain the above copyright
12 : * notice, this list of conditions and the following disclaimer.
13 : * 2. Redistributions in binary form must reproduce the above copyright
14 : * notice, this list of conditions and the following disclaimer in the
15 : * documentation and/or other materials provided with the distribution.
16 : *
17 : * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 : * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 : * SUCH DAMAGE.
28 : *
29 : * contrib/pgcrypto/px-hmac.c
30 : */
31 :
32 : #include "postgres.h"
33 :
34 : #include "px.h"
35 :
36 : #define HMAC_IPAD 0x36
37 : #define HMAC_OPAD 0x5C
38 :
39 : static unsigned
40 0 : hmac_result_size(PX_HMAC *h)
41 : {
42 0 : return px_md_result_size(h->md);
43 : }
44 :
45 : static unsigned
46 0 : hmac_block_size(PX_HMAC *h)
47 : {
48 0 : return px_md_block_size(h->md);
49 : }
50 :
51 : static void
52 0 : hmac_init(PX_HMAC *h, const uint8 *key, unsigned klen)
53 : {
54 0 : unsigned bs,
55 : i;
56 0 : uint8 *keybuf;
57 0 : PX_MD *md = h->md;
58 :
59 0 : bs = px_md_block_size(md);
60 0 : keybuf = palloc0(bs);
61 :
62 0 : if (klen > bs)
63 : {
64 0 : px_md_update(md, key, klen);
65 0 : px_md_finish(md, keybuf);
66 0 : px_md_reset(md);
67 0 : }
68 : else
69 0 : memcpy(keybuf, key, klen);
70 :
71 0 : for (i = 0; i < bs; i++)
72 : {
73 0 : h->p.ipad[i] = keybuf[i] ^ HMAC_IPAD;
74 0 : h->p.opad[i] = keybuf[i] ^ HMAC_OPAD;
75 0 : }
76 :
77 0 : px_memset(keybuf, 0, bs);
78 0 : pfree(keybuf);
79 :
80 0 : px_md_update(md, h->p.ipad, bs);
81 0 : }
82 :
83 : static void
84 0 : hmac_reset(PX_HMAC *h)
85 : {
86 0 : PX_MD *md = h->md;
87 0 : unsigned bs = px_md_block_size(md);
88 :
89 0 : px_md_reset(md);
90 0 : px_md_update(md, h->p.ipad, bs);
91 0 : }
92 :
93 : static void
94 0 : hmac_update(PX_HMAC *h, const uint8 *data, unsigned dlen)
95 : {
96 0 : px_md_update(h->md, data, dlen);
97 0 : }
98 :
99 : static void
100 0 : hmac_finish(PX_HMAC *h, uint8 *dst)
101 : {
102 0 : PX_MD *md = h->md;
103 0 : unsigned bs,
104 : hlen;
105 0 : uint8 *buf;
106 :
107 0 : bs = px_md_block_size(md);
108 0 : hlen = px_md_result_size(md);
109 :
110 0 : buf = palloc(hlen);
111 :
112 0 : px_md_finish(md, buf);
113 :
114 0 : px_md_reset(md);
115 0 : px_md_update(md, h->p.opad, bs);
116 0 : px_md_update(md, buf, hlen);
117 0 : px_md_finish(md, dst);
118 :
119 0 : px_memset(buf, 0, hlen);
120 0 : pfree(buf);
121 0 : }
122 :
123 : static void
124 0 : hmac_free(PX_HMAC *h)
125 : {
126 0 : unsigned bs;
127 :
128 0 : bs = px_md_block_size(h->md);
129 0 : px_md_free(h->md);
130 :
131 0 : px_memset(h->p.ipad, 0, bs);
132 0 : px_memset(h->p.opad, 0, bs);
133 0 : pfree(h->p.ipad);
134 0 : pfree(h->p.opad);
135 0 : pfree(h);
136 0 : }
137 :
138 :
139 : /* PUBLIC FUNCTIONS */
140 :
141 : int
142 0 : px_find_hmac(const char *name, PX_HMAC **res)
143 : {
144 0 : int err;
145 0 : PX_MD *md;
146 0 : PX_HMAC *h;
147 0 : unsigned bs;
148 :
149 0 : err = px_find_digest(name, &md);
150 0 : if (err)
151 0 : return err;
152 :
153 0 : bs = px_md_block_size(md);
154 0 : if (bs < 2)
155 : {
156 0 : px_md_free(md);
157 0 : return PXE_HASH_UNUSABLE_FOR_HMAC;
158 : }
159 :
160 0 : h = palloc_object(PX_HMAC);
161 0 : h->p.ipad = palloc(bs);
162 0 : h->p.opad = palloc(bs);
163 0 : h->md = md;
164 :
165 0 : h->result_size = hmac_result_size;
166 0 : h->block_size = hmac_block_size;
167 0 : h->reset = hmac_reset;
168 0 : h->update = hmac_update;
169 0 : h->finish = hmac_finish;
170 0 : h->free = hmac_free;
171 0 : h->init = hmac_init;
172 :
173 0 : *res = h;
174 :
175 0 : return 0;
176 0 : }
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