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35d66180 | 1 | /* -*-c-*- |
35d66180 | 2 | * |
3 | * Block cipher counter mode (or long cycle mode) | |
4 | * | |
5 | * (c) 2000 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
35d66180 | 9 | * |
10 | * This file is part of Catacomb. | |
11 | * | |
12 | * Catacomb is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU Library General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
45c0fd36 | 16 | * |
35d66180 | 17 | * Catacomb is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU Library General Public License for more details. | |
45c0fd36 | 21 | * |
35d66180 | 22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free | |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
25 | * MA 02111-1307, USA. | |
26 | */ | |
27 | ||
35d66180 | 28 | #ifndef CATACOMB_COUNTER_H |
29 | #define CATACOMB_COUNTER_H | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | /*----- Header files ------------------------------------------------------*/ | |
36 | ||
37 | #include <stddef.h> | |
38 | ||
39 | #include <mLib/bits.h> | |
40 | ||
41 | #ifndef CATACOMB_GCIPHER_H | |
42 | # include "gcipher.h" | |
43 | #endif | |
44 | ||
45 | #ifndef CATACOMB_GRAND_H | |
46 | # include "grand.h" | |
47 | #endif | |
48 | ||
49 | /*----- Macros ------------------------------------------------------------*/ | |
50 | ||
51 | /* --- @COUNTER_DECL@ --- * | |
52 | * | |
53 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions | |
54 | * | |
55 | * Use: Makes declarations for counter mode. | |
56 | */ | |
57 | ||
58 | #define COUNTER_DECL(PRE, pre) \ | |
59 | \ | |
60 | /* --- Counter mode context --- */ \ | |
61 | \ | |
62 | typedef struct pre##_counterctx { \ | |
63 | pre##_ctx ctx; /* Underlying cipher context */ \ | |
64 | unsigned off; /* Current offset in buffer */ \ | |
0fee61eb MW |
65 | octet b[PRE##_BLKSZ]; /* Output buffer */ \ |
66 | uint32 c[PRE##_BLKSZ / 4]; /* Counter */ \ | |
35d66180 | 67 | } pre##_counterctx; \ |
68 | \ | |
69 | /* --- @pre_countergetiv@ --- * \ | |
70 | * \ | |
71 | * Arguments: @const pre_counterctx *ctx@ = pointer to counter \ | |
72 | * context \ | |
4efe32ba | 73 | * @void *iv@ = pointer to output data block \ |
35d66180 | 74 | * \ |
75 | * Returns: --- \ | |
76 | * \ | |
77 | * Use: Reads the currently set IV. Reading and setting an IV \ | |
78 | * is not transparent to the cipher. It will add a `step' \ | |
79 | * which must be matched by a similar operation during \ | |
80 | * decryption. \ | |
81 | */ \ | |
82 | \ | |
83 | extern void pre##_countergetiv(const pre##_counterctx */*ctx*/, \ | |
84 | void */*iv*/); \ | |
85 | \ | |
86 | /* --- @pre_countersetiv@ --- * \ | |
87 | * \ | |
88 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
89 | * @cnost void *iv@ = pointer to IV to set \ | |
90 | * \ | |
91 | * Returns: --- \ | |
92 | * \ | |
93 | * Use: Sets the IV to use for subsequent encryption. \ | |
94 | */ \ | |
95 | \ | |
96 | extern void pre##_countersetiv(pre##_counterctx */*ctx*/, \ | |
97 | const void */*iv*/); \ | |
98 | \ | |
99 | /* --- @pre_counterbdry@ --- * \ | |
100 | * \ | |
101 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
102 | * \ | |
103 | * Returns: --- \ | |
104 | * \ | |
105 | * Use: Inserts a boundary during encryption. Successful \ | |
106 | * decryption must place a similar boundary. \ | |
107 | */ \ | |
108 | \ | |
109 | extern void pre##_counterbdry(pre##_counterctx */*ctx*/); \ | |
110 | \ | |
111 | /* --- @pre_countersetkey@ --- * \ | |
112 | * \ | |
113 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
114 | * @const pre_ctx *k@ = pointer to cipher context \ | |
115 | * \ | |
116 | * Returns: --- \ | |
117 | * \ | |
118 | * Use: Sets the counter context to use a different cipher key. \ | |
119 | */ \ | |
120 | \ | |
121 | extern void pre##_countersetkey(pre##_counterctx */*ctx*/, \ | |
122 | const pre##_ctx */*k*/); \ | |
123 | \ | |
124 | /* --- @pre_counterinit@ --- * \ | |
125 | * \ | |
126 | * Arguments: @pre_counterctx *ctx@ = pointer to cipher context \ | |
127 | * @const void *key@ = pointer to the key buffer \ | |
128 | * @size_t sz@ = size of the key \ | |
129 | * @const void *iv@ = pointer to initialization vector \ | |
130 | * \ | |
131 | * Returns: --- \ | |
132 | * \ | |
133 | * Use: Initializes a counter context ready for use. You \ | |
134 | * should ensure that the IV chosen is unique: reusing an \ | |
135 | * IV will compromise the security of the entire \ | |
136 | * plaintext. This is equivalent to calls to @pre_init@, \ | |
137 | * @pre_countersetkey@ and @pre_countersetiv@. \ | |
138 | */ \ | |
139 | \ | |
140 | extern void pre##_counterinit(pre##_counterctx */*ctx*/, \ | |
141 | const void */*key*/, size_t /*sz*/, \ | |
b9a27a11 | 142 | const void */*iv*/); \ |
35d66180 | 143 | \ |
144 | /* --- @pre_counterencrypt@ --- * \ | |
145 | * \ | |
146 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
147 | * @const void *src@ = pointer to source data \ | |
148 | * @void *dest@ = pointer to destination data \ | |
149 | * @size_t sz@ = size of block to be encrypted \ | |
150 | * \ | |
151 | * Returns: --- \ | |
152 | * \ | |
153 | * Use: Encrypts or decrypts a block with a block cipher in \ | |
154 | * counter mode: encryption and decryption are the same in \ | |
155 | * counter. The destination may be null to just churn the \ | |
156 | * feedback round for a bit. The source may be null to \ | |
157 | * use the cipher as a random data generator. \ | |
158 | */ \ | |
159 | \ | |
160 | extern void pre##_counterencrypt(pre##_counterctx */*ctx*/, \ | |
161 | const void */*src*/, void */*dest*/, \ | |
162 | size_t /*sz*/); \ | |
163 | \ | |
164 | /* --- @pre_counterrand@ --- * \ | |
165 | * \ | |
166 | * Arguments: @const void *k@ = pointer to key material \ | |
167 | * @size_t sz@ = size of key material \ | |
168 | * \ | |
169 | * Returns: Pointer to generic random number generator interface. \ | |
170 | * \ | |
171 | * Use: Creates a random number interface wrapper around an \ | |
172 | * counter-mode block cipher. \ | |
173 | */ \ | |
174 | \ | |
175 | extern grand *pre##_counterrand(const void */*k*/, size_t /*sz*/); \ | |
176 | \ | |
177 | /* --- Generic cipher interface --- */ \ | |
178 | \ | |
179 | extern const gccipher pre##_counter; | |
180 | ||
181 | /*----- That's all, folks -------------------------------------------------*/ | |
182 | ||
183 | #ifdef __cplusplus | |
184 | } | |
185 | #endif | |
186 | ||
187 | #endif |