cc-hash.c (fhash): The FILE name may be null.
[u/mdw/catacomb] / sha.h
1 /* -*-c-*-
2 *
3 * $Id: sha.h,v 1.6 2004/04/08 01:36:15 mdw Exp $
4 *
5 * Implementation of the SHA-1 hash function
6 *
7 * (c) 1999 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 /*----- Notes on the SHA-1 hash function ----------------------------------*
31 *
32 * SHA (Secure Hash Algorithm) was designed by the NSA, for use with the
33 * Digital Signature Algorithm. It is defined by FIPS 180-1. It has gained
34 * wide acceptance since its initial publication, and is probably now most
35 * people's collision-resistant function of choice. The author prefers
36 * RIPEMD-160, for no particularly good reasons.
37 */
38
39 #ifndef CATACOMB_SHA_H
40 #define CATACOMB_SHA_H
41
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45
46 /*----- Header files ------------------------------------------------------*/
47
48 #include <mLib/bits.h>
49
50 #ifndef CATACOMB_GHASH_H
51 # include "ghash.h"
52 #endif
53
54 /*----- Magic numbers -----------------------------------------------------*/
55
56 #define SHA_BUFSZ 64
57 #define SHA_HASHSZ 20
58 #define SHA_STATESZ 20
59
60 /*----- Data structures ---------------------------------------------------*/
61
62 typedef struct sha_ctx {
63 uint32 a, b, c, d, e; /* Chaining variables */
64 uint32 nl, nh; /* Byte count so far */
65 unsigned off; /* Offset into buffer */
66 octet buf[SHA_BUFSZ]; /* Accumulation buffer */
67 } sha_ctx;
68
69 /*----- Functions provided ------------------------------------------------*/
70
71 /* --- @sha_compress@ --- *
72 *
73 * Arguments: @sha_ctx *ctx@ = pointer to context block
74 * @const void *sbuf@ = pointer to buffer of appropriate size
75 *
76 * Returns: ---
77 *
78 * Use: SHA compression function.
79 */
80
81 extern void sha_compress(sha_ctx */*ctx*/, const void */*sbuf*/);
82
83 /* --- @sha_init@ --- *
84 *
85 * Arguments: @sha_ctx *ctx@ = pointer to context block to initialize
86 *
87 * Returns: ---
88 *
89 * Use: Initializes a context block ready for hashing.
90 */
91
92 extern void sha_init(sha_ctx */*ctx*/);
93
94 /* --- @sha_set@ --- *
95 *
96 * Arguments: @sha_ctx *ctx@ = pointer to context block
97 * @const void *buf@ = pointer to state buffer
98 * @unsigned long count@ = current count of bytes processed
99 *
100 * Returns: ---
101 *
102 * Use: Initializes a context block from a given state. This is
103 * useful in cases where the initial hash state is meant to be
104 * secret, e.g., for NMAC and HMAC support.
105 */
106
107 extern void sha_set(sha_ctx */*ctx*/, const void */*buf*/,
108 unsigned long /*count*/);
109
110 /* --- @sha_hash@ --- *
111 *
112 * Arguments: @sha_ctx *ctx@ = pointer to context block
113 * @const void *buf@ = buffer of data to hash
114 * @size_t sz@ = size of buffer to hash
115 *
116 * Returns: ---
117 *
118 * Use: Hashes a buffer of data. The buffer may be of any size and
119 * alignment.
120 */
121
122 extern void sha_hash(sha_ctx */*ctx*/, const void */*buf*/, size_t /*sz*/);
123
124 /* --- @sha_done@ --- *
125 *
126 * Arguments: @sha_ctx *ctx@ = pointer to context block
127 * @void *hash@ = pointer to output buffer
128 *
129 * Returns: ---
130 *
131 * Use: Returns the hash of the data read so far.
132 */
133
134 extern void sha_done(sha_ctx */*ctx*/, void */*hash*/);
135
136 /* --- @sha_state@ --- *
137 *
138 * Arguments: @sha_ctx *ctx@ = pointer to context
139 * @void *state@ = pointer to buffer for current state
140 *
141 * Returns: Number of bytes written to the hash function so far.
142 *
143 * Use: Returns the current state of the hash function such that
144 * it can be passed to @sha_set@.
145 */
146
147 extern unsigned long sha_state(sha_ctx */*ctx*/, void */*state*/);
148
149 /*----- Generic hash interface --------------------------------------------*/
150
151 extern const gchash sha;
152
153 /*----- That's all, folks -------------------------------------------------*/
154
155 #ifdef __cplusplus
156 }
157 #endif
158
159 #endif