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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: sha256.h,v 1.4 2004/04/08 01:36:15 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 | |
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30 | /*----- Notes on the SHA-256 hash function ----------------------------------* |
31 | * |
32 | * SHA-1 (Secure Hash Algorithm) was designed by the NSA, for use with the |
33 | * Digital Signature Algorithm. This is an evolution with a larger output |
34 | * size, intended to provide security commensurate with 128-bit AES. At the |
35 | * time of writing, SHA-256 is very new, and can't be trusted too far. |
36 | */ |
37 | |
38 | #ifndef CATACOMB_SHA256_H |
39 | #define CATACOMB_SHA256_H |
40 | |
41 | #ifdef __cplusplus |
42 | extern "C" { |
43 | #endif |
44 | |
45 | /*----- Header files ------------------------------------------------------*/ |
46 | |
47 | #include <mLib/bits.h> |
48 | |
49 | #ifndef CATACOMB_GHASH_H |
50 | # include "ghash.h" |
51 | #endif |
52 | |
53 | /*----- Magic numbers -----------------------------------------------------*/ |
54 | |
55 | #define SHA256_BUFSZ 64 |
56 | #define SHA256_HASHSZ 32 |
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57 | #define SHA256_STATESZ 32 |
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58 | |
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59 | #define SHA224_BUFSZ 64 |
60 | #define SHA224_HASHSZ 28 |
61 | #define SHA224_STATESZ 32 |
62 | |
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63 | /*----- Data structures ---------------------------------------------------*/ |
64 | |
65 | typedef struct sha256_ctx { |
66 | uint32 a, b, c, d, e, f, g, h; /* Chaining variables */ |
67 | uint32 nl, nh; /* Byte count so far */ |
68 | unsigned off; /* Offset into buffer */ |
69 | octet buf[SHA256_BUFSZ]; /* Accumulation buffer */ |
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70 | } sha256_ctx, sha224_ctx; |
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71 | |
72 | /*----- Functions provided ------------------------------------------------*/ |
73 | |
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74 | /* --- @sha256_compress@, @sha224_compress@ --- * |
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75 | * |
76 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
77 | * @const void *sbuf@ = pointer to buffer of appropriate size |
78 | * |
79 | * Returns: --- |
80 | * |
81 | * Use: SHA-256 compression function. |
82 | */ |
83 | |
84 | extern void sha256_compress(sha256_ctx */*ctx*/, const void */*sbuf*/); |
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85 | #define sha224_compress sha256_compress |
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86 | |
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87 | /* --- @sha256_init@, @sha224_init@ --- * |
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88 | * |
89 | * Arguments: @sha256_ctx *ctx@ = pointer to context block to initialize |
90 | * |
91 | * Returns: --- |
92 | * |
93 | * Use: Initializes a context block ready for hashing. |
94 | */ |
95 | |
96 | extern void sha256_init(sha256_ctx */*ctx*/); |
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97 | extern void sha224_init(sha256_ctx */*ctx*/); |
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98 | |
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99 | /* --- @sha256_set@, @sha224_set@ --- * |
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100 | * |
101 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
102 | * @const void *buf@ = pointer to state buffer |
103 | * @unsigned long count@ = current count of bytes processed |
104 | * |
105 | * Returns: --- |
106 | * |
107 | * Use: Initializes a context block from a given state. This is |
108 | * useful in cases where the initial hash state is meant to be |
109 | * secret, e.g., for NMAC and HMAC support. |
110 | */ |
111 | |
112 | extern void sha256_set(sha256_ctx */*ctx*/, const void */*buf*/, |
113 | unsigned long /*count*/); |
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114 | #define sha224_set sha256_set |
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115 | |
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116 | /* --- @sha256_hash@, @sha224_hash@ --- * |
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117 | * |
118 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
119 | * @const void *buf@ = buffer of data to hash |
120 | * @size_t sz@ = size of buffer to hash |
121 | * |
122 | * Returns: --- |
123 | * |
124 | * Use: Hashes a buffer of data. The buffer may be of any size and |
125 | * alignment. |
126 | */ |
127 | |
128 | extern void sha256_hash(sha256_ctx */*ctx*/, |
129 | const void */*buf*/, size_t /*sz*/); |
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130 | #define sha224_hash sha256_hash |
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131 | |
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132 | /* --- @sha256_done@, @sha224_done@ --- * |
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133 | * |
134 | * Arguments: @sha256_ctx *ctx@ = pointer to context block |
135 | * @void *hash@ = pointer to output buffer |
136 | * |
137 | * Returns: --- |
138 | * |
139 | * Use: Returns the hash of the data read so far. |
140 | */ |
141 | |
142 | extern void sha256_done(sha256_ctx */*ctx*/, void */*hash*/); |
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143 | extern void sha224_done(sha256_ctx */*ctx*/, void */*hash*/); |
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144 | |
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145 | /* --- @sha256_state@, @sha224_state@ --- * |
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146 | * |
147 | * Arguments: @sha256_ctx *ctx@ = pointer to context |
148 | * @void *state@ = pointer to buffer for current state |
149 | * |
150 | * Returns: Number of bytes written to the hash function so far. |
151 | * |
152 | * Use: Returns the current state of the hash function such that |
153 | * it can be passed to @sha256_set@. |
154 | */ |
155 | |
156 | extern unsigned long sha256_state(sha256_ctx */*ctx*/, void */*state*/); |
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157 | #define sha224_state sha256_state |
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158 | |
159 | /*----- Generic hash interface --------------------------------------------*/ |
160 | |
161 | extern const gchash sha256; |
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162 | extern const gchash sha224; |
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163 | |
164 | /*----- That's all, folks -------------------------------------------------*/ |
165 | |
166 | #ifdef __cplusplus |
167 | } |
168 | #endif |
169 | |
170 | #endif |