d03ab969 |
1 | /* -*-c-*- |
2 | * |
c850c0da |
3 | * $Id: hmac.h,v 1.4 2000/10/15 19:09:20 mdw Exp $ |
d03ab969 |
4 | * |
5 | * Generic code for HMAC and NMAC |
6 | * |
7 | * (c) 1998 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: hmac.h,v $ |
c850c0da |
33 | * Revision 1.4 2000/10/15 19:09:20 mdw |
34 | * Support HMAC mode for hash functions which need to store more state than |
35 | * the hash output size. |
36 | * |
6ced98bd |
37 | * Revision 1.3 2000/06/17 11:23:57 mdw |
38 | * New key size interface. |
39 | * |
79ba130c |
40 | * Revision 1.2 1999/12/10 23:17:39 mdw |
41 | * Split mode macros into interface and implementation. |
42 | * |
d03ab969 |
43 | * Revision 1.1 1999/09/03 08:41:12 mdw |
44 | * Initial import. |
45 | * |
46 | */ |
47 | |
48 | /*----- Notes on the HMAC and NMAC constructions --------------------------* |
49 | * |
79ba130c |
50 | * Designed by Mihir Bellare, Ran Canetti and Hugo Krawczyk, NMAC is a method |
51 | * for constructing keyed message authentication algorithms from unkeyed hash |
52 | * functions. It has been proven to provide useful security given reasonable |
53 | * assumptions about the underlying hash function. HMAC is an alternative |
54 | * formulation which doesn't require low-level access to the hash function's |
55 | * implementation. NMAC was designed to allow MD5 has a suitable underlying |
56 | * hash function, even though doubts were already being raised about its |
57 | * collision resistance. |
d03ab969 |
58 | */ |
59 | |
79ba130c |
60 | #ifndef CATACOMB_HMAC_H |
61 | #define CATACOMB_HMAC_H |
d03ab969 |
62 | |
63 | #ifdef __cplusplus |
64 | extern "C" { |
65 | #endif |
66 | |
67 | /*----- Header files ------------------------------------------------------*/ |
68 | |
79ba130c |
69 | #include <stddef.h> |
d03ab969 |
70 | |
71 | #include <mLib/bits.h> |
72 | |
79ba130c |
73 | #ifndef CATACOMB_GMAC_H |
74 | # include "gmac.h" |
d03ab969 |
75 | #endif |
76 | |
77 | /*----- Macros ------------------------------------------------------------*/ |
78 | |
79 | /* --- @HMAC_DECL@ --- * |
80 | * |
81 | * Arguments: @PRE@, @pre@ = prefixes for the underlying hash function |
82 | * |
83 | * Use: Creates declarations for the HMAC and NMAC functions. |
84 | */ |
85 | |
86 | #define HMAC_DECL(PRE, pre) \ |
87 | \ |
79ba130c |
88 | /* --- An HMAC or NMAC key --- */ \ |
89 | \ |
d03ab969 |
90 | typedef struct pre##_mackey { \ |
c850c0da |
91 | octet ochain[PRE##_STATESZ]; /* Chaining for outer hash */ \ |
79ba130c |
92 | unsigned ocount; /* Byte count for outer hash */ \ |
c850c0da |
93 | octet ichain[PRE##_STATESZ]; /* Chaining for inner hash */ \ |
79ba130c |
94 | unsigned icount; /* Byte count for inner hash */ \ |
d03ab969 |
95 | } pre##_mackey; \ |
96 | \ |
79ba130c |
97 | /* --- An HMAC or NMAC hashing context --- */ \ |
98 | \ |
d03ab969 |
99 | typedef struct pre##_macctx { \ |
100 | pre##_ctx ctx; /* Context for main hashing */ \ |
c850c0da |
101 | octet chain[PRE##_STATESZ]; /* Chaining for outer hash */ \ |
79ba130c |
102 | unsigned count; /* Byte count for outer hash */ \ |
d03ab969 |
103 | } pre##_macctx; \ |
104 | \ |
6ced98bd |
105 | /* --- Other useful constants --- */ \ |
106 | \ |
107 | extern const octet pre##_mackeysz[]; \ |
108 | \ |
79ba130c |
109 | /* --- @pre_nmacinit@ --- * \ |
d03ab969 |
110 | * \ |
111 | * Arguments: @pre_macctx *key@ = pointer to a MAC key object \ |
112 | * @const void *ok@ = pointer to outer hash init vector \ |
113 | * @const void *ik@ = pointer to inner hash init vector \ |
114 | * \ |
115 | * Returns: --- \ |
116 | * \ |
117 | * Use: Initializes a MAC key for doing NMAC hashing. \ |
118 | */ \ |
119 | \ |
79ba130c |
120 | extern void pre##_nmacinit(pre##_mackey */*key*/, \ |
121 | const void */*ok*/, const void */*ik*/); \ |
d03ab969 |
122 | \ |
79ba130c |
123 | /* --- @pre_hmacinit@ --- * \ |
d03ab969 |
124 | * \ |
125 | * Arguments: @pre_mackey *key@ = pointer to MAC key object \ |
126 | * @const void *k@ = pointer to key to use \ |
127 | * @size_t sz@ = size of key data \ |
128 | * \ |
129 | * Returns: --- \ |
130 | * \ |
131 | * Use: Initializes a MAC key for doing HMAC hashing. Keys \ |
132 | * longer than the hash function's output size aren't very \ |
133 | * useful, but are accepted. Keys longer than the hash's \ |
134 | * block size are also accepted; they are hashed before \ |
135 | * use, as specified in RFC2104. \ |
136 | */ \ |
137 | \ |
79ba130c |
138 | extern void pre##_hmacinit(pre##_mackey */*key*/, \ |
139 | const void */*k*/, size_t /*sz*/); \ |
d03ab969 |
140 | \ |
141 | /* --- @pre_macinit@ --- * \ |
142 | * \ |
143 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
144 | * @const pre_mackey *key@ = pointer to MAC key block \ |
145 | * \ |
146 | * Returns: --- \ |
147 | * \ |
148 | * Use: Instantiates a MAC context from a key block. \ |
149 | */ \ |
150 | \ |
79ba130c |
151 | extern void pre##_macinit(pre##_macctx */*ctx*/, \ |
152 | const pre##_mackey */*key*/); \ |
d03ab969 |
153 | \ |
79ba130c |
154 | /* --- @pre_machash@ --- * \ |
d03ab969 |
155 | * \ |
156 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
157 | * @const void *buf@ = pointer to buffer \ |
158 | * @size_t sz@ = size of the buffer \ |
159 | * \ |
160 | * Returns: --- \ |
161 | * \ |
162 | * Use: Hashes a buffer. \ |
163 | */ \ |
164 | \ |
79ba130c |
165 | extern void pre##_machash(pre##_macctx */*ctx*/, \ |
166 | const void */*buf*/, size_t /*sz*/); \ |
d03ab969 |
167 | \ |
168 | /* --- @pre_macdone@ --- * \ |
169 | * \ |
170 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
171 | * @void *mac@ = pointer to buffer to receive MAC \ |
172 | * \ |
173 | * Returns: --- \ |
174 | * \ |
175 | * Use: Returns the result of a MAC computation. \ |
176 | */ \ |
177 | \ |
79ba130c |
178 | extern void pre##_macdone(pre##_macctx */*ctx*/, void */*mac*/); \ |
d03ab969 |
179 | \ |
79ba130c |
180 | /* --- Generic MAC interface --- */ \ |
d03ab969 |
181 | \ |
79ba130c |
182 | extern const gcmac pre##_hmac; |
d03ab969 |
183 | |
184 | /*----- That's all, folks -------------------------------------------------*/ |
185 | |
186 | #ifdef __cplusplus |
187 | } |
188 | #endif |
189 | |
190 | #endif |