3 * $Id: sha256.h,v 1.3 2004/03/21 22:43:34 mdw Exp $
5 * Implementation of the SHA-256 hash function
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.3 2004/03/21 22:43:34 mdw
34 * New hash variant SHA224.
36 * Revision 1.2 2000/10/15 19:09:20 mdw
37 * Support HMAC mode for hash functions which need to store more state than
38 * the hash output size.
40 * Revision 1.1 2000/10/15 17:48:15 mdw
41 * New SHA variants with longer outputs.
45 /*----- Notes on the SHA-256 hash function ----------------------------------*
47 * SHA-1 (Secure Hash Algorithm) was designed by the NSA, for use with the
48 * Digital Signature Algorithm. This is an evolution with a larger output
49 * size, intended to provide security commensurate with 128-bit AES. At the
50 * time of writing, SHA-256 is very new, and can't be trusted too far.
53 #ifndef CATACOMB_SHA256_H
54 #define CATACOMB_SHA256_H
60 /*----- Header files ------------------------------------------------------*/
62 #include <mLib/bits.h>
64 #ifndef CATACOMB_GHASH_H
68 /*----- Magic numbers -----------------------------------------------------*/
70 #define SHA256_BUFSZ 64
71 #define SHA256_HASHSZ 32
72 #define SHA256_STATESZ 32
74 #define SHA224_BUFSZ 64
75 #define SHA224_HASHSZ 28
76 #define SHA224_STATESZ 32
78 /*----- Data structures ---------------------------------------------------*/
80 typedef struct sha256_ctx
{
81 uint32 a
, b
, c
, d
, e
, f
, g
, h
; /* Chaining variables */
82 uint32 nl
, nh
; /* Byte count so far */
83 unsigned off
; /* Offset into buffer */
84 octet buf
[SHA256_BUFSZ
]; /* Accumulation buffer */
85 } sha256_ctx
, sha224_ctx
;
87 /*----- Functions provided ------------------------------------------------*/
89 /* --- @sha256_compress@, @sha224_compress@ --- *
91 * Arguments: @sha256_ctx *ctx@ = pointer to context block
92 * @const void *sbuf@ = pointer to buffer of appropriate size
96 * Use: SHA-256 compression function.
99 extern void sha256_compress(sha256_ctx */
*ctx*/
, const void */
*sbuf*/
);
100 #define sha224_compress sha256_compress
102 /* --- @sha256_init@, @sha224_init@ --- *
104 * Arguments: @sha256_ctx *ctx@ = pointer to context block to initialize
108 * Use: Initializes a context block ready for hashing.
111 extern void sha256_init(sha256_ctx */
*ctx*/
);
112 extern void sha224_init(sha256_ctx */
*ctx*/
);
114 /* --- @sha256_set@, @sha224_set@ --- *
116 * Arguments: @sha256_ctx *ctx@ = pointer to context block
117 * @const void *buf@ = pointer to state buffer
118 * @unsigned long count@ = current count of bytes processed
122 * Use: Initializes a context block from a given state. This is
123 * useful in cases where the initial hash state is meant to be
124 * secret, e.g., for NMAC and HMAC support.
127 extern void sha256_set(sha256_ctx */
*ctx*/
, const void */
*buf*/
,
128 unsigned long /*count*/);
129 #define sha224_set sha256_set
131 /* --- @sha256_hash@, @sha224_hash@ --- *
133 * Arguments: @sha256_ctx *ctx@ = pointer to context block
134 * @const void *buf@ = buffer of data to hash
135 * @size_t sz@ = size of buffer to hash
139 * Use: Hashes a buffer of data. The buffer may be of any size and
143 extern void sha256_hash(sha256_ctx */
*ctx*/
,
144 const void */
*buf*/
, size_t /*sz*/);
145 #define sha224_hash sha256_hash
147 /* --- @sha256_done@, @sha224_done@ --- *
149 * Arguments: @sha256_ctx *ctx@ = pointer to context block
150 * @void *hash@ = pointer to output buffer
154 * Use: Returns the hash of the data read so far.
157 extern void sha256_done(sha256_ctx */
*ctx*/
, void */
*hash*/
);
158 extern void sha224_done(sha256_ctx */
*ctx*/
, void */
*hash*/
);
160 /* --- @sha256_state@, @sha224_state@ --- *
162 * Arguments: @sha256_ctx *ctx@ = pointer to context
163 * @void *state@ = pointer to buffer for current state
165 * Returns: Number of bytes written to the hash function so far.
167 * Use: Returns the current state of the hash function such that
168 * it can be passed to @sha256_set@.
171 extern unsigned long sha256_state(sha256_ctx */
*ctx*/
, void */
*state*/
);
172 #define sha224_state sha256_state
174 /*----- Generic hash interface --------------------------------------------*/
176 extern const gchash sha256
;
177 extern const gchash sha224
;
179 /*----- That's all, folks -------------------------------------------------*/