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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: sha256.h,v 1.2 2000/10/15 19:09:20 mdw Exp $ |
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4 | * |
5 | * Implementation of the SHA-256 hash function |
6 | * |
7 | * (c) 2000 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: sha256.h,v $ |
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33 | * Revision 1.2 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 | * |
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37 | * Revision 1.1 2000/10/15 17:48:15 mdw |
38 | * New SHA variants with longer outputs. |
39 | * |
40 | */ |
41 | |
42 | /*----- Notes on the SHA-256 hash function ----------------------------------* |
43 | * |
44 | * SHA-1 (Secure Hash Algorithm) was designed by the NSA, for use with the |
45 | * Digital Signature Algorithm. This is an evolution with a larger output |
46 | * size, intended to provide security commensurate with 128-bit AES. At the |
47 | * time of writing, SHA-256 is very new, and can't be trusted too far. |
48 | */ |
49 | |
50 | #ifndef CATACOMB_SHA256_H |
51 | #define CATACOMB_SHA256_H |
52 | |
53 | #ifdef __cplusplus |
54 | extern "C" { |
55 | #endif |
56 | |
57 | /*----- Header files ------------------------------------------------------*/ |
58 | |
59 | #include <mLib/bits.h> |
60 | |
61 | #ifndef CATACOMB_GHASH_H |
62 | # include "ghash.h" |
63 | #endif |
64 | |
65 | /*----- Magic numbers -----------------------------------------------------*/ |
66 | |
67 | #define SHA256_BUFSZ 64 |
68 | #define SHA256_HASHSZ 32 |
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69 | #define SHA256_STATESZ 32 |
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70 | |
71 | /*----- Data structures ---------------------------------------------------*/ |
72 | |
73 | typedef struct sha256_ctx { |
74 | uint32 a, b, c, d, e, f, g, h; /* Chaining variables */ |
75 | uint32 nl, nh; /* Byte count so far */ |
76 | unsigned off; /* Offset into buffer */ |
77 | octet buf[SHA256_BUFSZ]; /* Accumulation buffer */ |
78 | } sha256_ctx; |
79 | |
80 | /*----- Functions provided ------------------------------------------------*/ |
81 | |
82 | /* --- @sha256_compress@ --- * |
83 | * |
84 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
85 | * @const void *sbuf@ = pointer to buffer of appropriate size |
86 | * |
87 | * Returns: --- |
88 | * |
89 | * Use: SHA-256 compression function. |
90 | */ |
91 | |
92 | extern void sha256_compress(sha256_ctx */*ctx*/, const void */*sbuf*/); |
93 | |
94 | /* --- @sha256_init@ --- * |
95 | * |
96 | * Arguments: @sha256_ctx *ctx@ = pointer to context block to initialize |
97 | * |
98 | * Returns: --- |
99 | * |
100 | * Use: Initializes a context block ready for hashing. |
101 | */ |
102 | |
103 | extern void sha256_init(sha256_ctx */*ctx*/); |
104 | |
105 | /* --- @sha256_set@ --- * |
106 | * |
107 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
108 | * @const void *buf@ = pointer to state buffer |
109 | * @unsigned long count@ = current count of bytes processed |
110 | * |
111 | * Returns: --- |
112 | * |
113 | * Use: Initializes a context block from a given state. This is |
114 | * useful in cases where the initial hash state is meant to be |
115 | * secret, e.g., for NMAC and HMAC support. |
116 | */ |
117 | |
118 | extern void sha256_set(sha256_ctx */*ctx*/, const void */*buf*/, |
119 | unsigned long /*count*/); |
120 | |
121 | /* --- @sha256_hash@ --- * |
122 | * |
123 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
124 | * @const void *buf@ = buffer of data to hash |
125 | * @size_t sz@ = size of buffer to hash |
126 | * |
127 | * Returns: --- |
128 | * |
129 | * Use: Hashes a buffer of data. The buffer may be of any size and |
130 | * alignment. |
131 | */ |
132 | |
133 | extern void sha256_hash(sha256_ctx */*ctx*/, |
134 | const void */*buf*/, size_t /*sz*/); |
135 | |
136 | /* --- @sha256_done@ --- * |
137 | * |
138 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
139 | * @void *hash@ = pointer to output buffer |
140 | * |
141 | * Returns: --- |
142 | * |
143 | * Use: Returns the hash of the data read so far. |
144 | */ |
145 | |
146 | extern void sha256_done(sha256_ctx */*ctx*/, void */*hash*/); |
147 | |
148 | /* --- @sha256_state@ --- * |
149 | * |
150 | * Arguments: @sha256_ctx *ctx@ = pointer to context |
151 | * @void *state@ = pointer to buffer for current state |
152 | * |
153 | * Returns: Number of bytes written to the hash function so far. |
154 | * |
155 | * Use: Returns the current state of the hash function such that |
156 | * it can be passed to @sha256_set@. |
157 | */ |
158 | |
159 | extern unsigned long sha256_state(sha256_ctx */*ctx*/, void */*state*/); |
160 | |
161 | /*----- Generic hash interface --------------------------------------------*/ |
162 | |
163 | extern const gchash sha256; |
164 | |
165 | /*----- That's all, folks -------------------------------------------------*/ |
166 | |
167 | #ifdef __cplusplus |
168 | } |
169 | #endif |
170 | |
171 | #endif |