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Generate precomputed tables as sources in `precomps/'.
[u/mdw/catacomb] / symm / blowfish.c
1 /* -*-c-*-
2 *
3 * The Blowfish block cipher
4 *
5 * (c) 1998 Straylight/Edgeware
6 */
7
8 /*----- Licensing notice --------------------------------------------------*
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.
16 *
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.
21 *
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
28 /*----- Header files ------------------------------------------------------*/
29
30 #include <mLib/bits.h>
31
32 #include "blowfish.h"
33 #include "blkc.h"
34 #include "gcipher.h"
35 #include "paranoia.h"
36
37 /*----- Global variables --------------------------------------------------*/
38
39 extern const blowfish_ctx blowfish_ikey;
40
41 const octet blowfish_keysz[] = { KSZ_RANGE, BLOWFISH_KEYSZ, 1, 56, 1 };
42
43 /*----- Macros ------------------------------------------------------------*/
44
45 #define ROUND(k, x, y, r) do { \
46 x ^= *r; \
47 y ^= ((k->s0[U8(x >> 24)] + \
48 k->s1[U8(x >> 16)]) ^ \
49 k->s2[U8(x >> 8)]) + \
50 k->s3[U8(x >> 0)]; \
51 } while (0)
52
53 #define EBLK(k, a, b, c, d) do { \
54 const uint32 *_r = k->p; \
55 uint32 _x = a; \
56 uint32 _y = b; \
57 ROUND(k, _x, _y, _r++); \
58 ROUND(k, _y, _x, _r++); \
59 ROUND(k, _x, _y, _r++); \
60 ROUND(k, _y, _x, _r++); \
61 ROUND(k, _x, _y, _r++); \
62 ROUND(k, _y, _x, _r++); \
63 ROUND(k, _x, _y, _r++); \
64 ROUND(k, _y, _x, _r++); \
65 ROUND(k, _x, _y, _r++); \
66 ROUND(k, _y, _x, _r++); \
67 ROUND(k, _x, _y, _r++); \
68 ROUND(k, _y, _x, _r++); \
69 ROUND(k, _x, _y, _r++); \
70 ROUND(k, _y, _x, _r++); \
71 ROUND(k, _x, _y, _r++); \
72 ROUND(k, _y, _x, _r++); \
73 c = _y ^ k->p[17]; \
74 d = _x ^ k->p[16]; \
75 } while (0)
76
77 #define DBLK(k, a, b, c, d) do { \
78 const uint32 *_r = k->p + 18; \
79 uint32 _x = a; \
80 uint32 _y = b; \
81 ROUND(k, _x, _y, --_r); \
82 ROUND(k, _y, _x, --_r); \
83 ROUND(k, _x, _y, --_r); \
84 ROUND(k, _y, _x, --_r); \
85 ROUND(k, _x, _y, --_r); \
86 ROUND(k, _y, _x, --_r); \
87 ROUND(k, _x, _y, --_r); \
88 ROUND(k, _y, _x, --_r); \
89 ROUND(k, _x, _y, --_r); \
90 ROUND(k, _y, _x, --_r); \
91 ROUND(k, _x, _y, --_r); \
92 ROUND(k, _y, _x, --_r); \
93 ROUND(k, _x, _y, --_r); \
94 ROUND(k, _y, _x, --_r); \
95 ROUND(k, _x, _y, --_r); \
96 ROUND(k, _y, _x, --_r); \
97 c = _y ^ k->p[0]; \
98 d = _x ^ k->p[1]; \
99 } while (0)
100
101 /*----- Low-level encryption interface ------------------------------------*/
102
103 /* --- @blowfish_init@ --- *
104 *
105 * Arguments: @blowfish_ctx *k@ = pointer to key block to fill in
106 * @const void *buf@ = pointer to buffer of key material
107 * @size_t sz@ = size of key material
108 *
109 * Returns: ---
110 *
111 * Use: Initializes a Blowfish key buffer. Blowfish accepts
112 * a more-or-less arbitrary size key.
113 */
114
115 void blowfish_init(blowfish_ctx *k, const void *buf, size_t sz)
116 {
117 KSZ_ASSERT(blowfish, sz);
118
119 /* --- Copy the initial value over --- */
120
121 *k = blowfish_ikey;
122
123 /* --- Initialize the %$P$% array --- */
124
125 {
126 const octet *p = buf;
127 const octet *q = p + sz;
128 int i = 0, j = 0;
129 uint32 x = 0;
130
131 while (i < 18) {
132 x = (x << 8) | U8(*p++);
133 if (p >= q)
134 p = buf;
135 if (++j >= 4) {
136 k->p[i++] ^= x;
137 x = 0;
138 j = 0;
139 }
140 }
141
142 x = 0;
143 }
144
145 /* --- Now mangle the complete array of keys --- */
146
147 {
148 uint32 b[2];
149 int i;
150
151 b[0] = b[1] = 0;
152
153 for (i = 0; i < 18; i += 2) {
154 blowfish_eblk(k, b, b);
155 k->p[i] = b[0]; k->p[i + 1] = b[1];
156 }
157
158 for (i = 0; i < 256; i += 2) {
159 blowfish_eblk(k, b, b);
160 k->s0[i] = b[0]; k->s0[i + 1] = b[1];
161 }
162
163 for (i = 0; i < 256; i += 2) {
164 blowfish_eblk(k, b, b);
165 k->s1[i] = b[0]; k->s1[i + 1] = b[1];
166 }
167
168 for (i = 0; i < 256; i += 2) {
169 blowfish_eblk(k, b, b);
170 k->s2[i] = b[0]; k->s2[i + 1] = b[1];
171 }
172
173 for (i = 0; i < 256; i += 2) {
174 blowfish_eblk(k, b, b);
175 k->s3[i] = b[0]; k->s3[i + 1] = b[1];
176 }
177
178 BURN(b);
179 }
180 }
181
182 /* --- @blowfish_eblk@, @blowfish_dblk@ --- *
183 *
184 * Arguments: @const blowfish_ctx *k@ = pointer to key block
185 * @const uint32 s[2]@ = pointer to source block
186 * @uint32 d[2]@ = pointer to destination block
187 *
188 * Returns: ---
189 *
190 * Use: Low-level block encryption and decryption.
191 */
192
193 void blowfish_eblk(const blowfish_ctx *k, const uint32 *s, uint32 *d)
194 {
195 EBLK(k, s[0], s[1], d[0], d[1]);
196 }
197
198 void blowfish_dblk(const blowfish_ctx *k, const uint32 *s, uint32 *d)
199 {
200 DBLK(k, s[0], s[1], d[0], d[1]);
201 }
202
203 BLKC_TEST(BLOWFISH, blowfish)
204
205 /*----- That's all, folks -------------------------------------------------*/
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)