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Merge branch 'master' of git+ssh://metalzone.distorted.org.uk/~mdw/public-git/catacomb/
[u/mdw/catacomb] / blowfish.c
1 /* -*-c-*-
2 *
3 * $Id: blowfish.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
4 *
5 * The Blowfish block cipher
6 *
7 * (c) 1998 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 /*----- Header files ------------------------------------------------------*/
31
32 #include <mLib/bits.h>
33
34 #include "blowfish.h"
35 #include "blowfish-tab.h"
36 #include "blkc.h"
37 #include "gcipher.h"
38 #include "paranoia.h"
39
40 /*----- Global variables --------------------------------------------------*/
41
42 static const blowfish_ctx ikey = BLOWFISH_IKEY;
43
44 const octet blowfish_keysz[] = { KSZ_RANGE, BLOWFISH_KEYSZ, 1, 56, 1 };
45
46 /*----- Macros ------------------------------------------------------------*/
47
48 #define ROUND(k, x, y, r) do { \
49 x ^= *r; \
50 y ^= ((k->s0[U8(x >> 24)] + \
51 k->s1[U8(x >> 16)]) ^ \
52 k->s2[U8(x >> 8)]) + \
53 k->s3[U8(x >> 0)]; \
54 } while (0)
55
56 #define EBLK(k, a, b, c, d) do { \
57 const uint32 *_r = k->p; \
58 uint32 _x = a; \
59 uint32 _y = b; \
60 ROUND(k, _x, _y, _r++); \
61 ROUND(k, _y, _x, _r++); \
62 ROUND(k, _x, _y, _r++); \
63 ROUND(k, _y, _x, _r++); \
64 ROUND(k, _x, _y, _r++); \
65 ROUND(k, _y, _x, _r++); \
66 ROUND(k, _x, _y, _r++); \
67 ROUND(k, _y, _x, _r++); \
68 ROUND(k, _x, _y, _r++); \
69 ROUND(k, _y, _x, _r++); \
70 ROUND(k, _x, _y, _r++); \
71 ROUND(k, _y, _x, _r++); \
72 ROUND(k, _x, _y, _r++); \
73 ROUND(k, _y, _x, _r++); \
74 ROUND(k, _x, _y, _r++); \
75 ROUND(k, _y, _x, _r++); \
76 c = _y ^ k->p[17]; \
77 d = _x ^ k->p[16]; \
78 } while (0)
79
80 #define DBLK(k, a, b, c, d) do { \
81 const uint32 *_r = k->p + 18; \
82 uint32 _x = a; \
83 uint32 _y = b; \
84 ROUND(k, _x, _y, --_r); \
85 ROUND(k, _y, _x, --_r); \
86 ROUND(k, _x, _y, --_r); \
87 ROUND(k, _y, _x, --_r); \
88 ROUND(k, _x, _y, --_r); \
89 ROUND(k, _y, _x, --_r); \
90 ROUND(k, _x, _y, --_r); \
91 ROUND(k, _y, _x, --_r); \
92 ROUND(k, _x, _y, --_r); \
93 ROUND(k, _y, _x, --_r); \
94 ROUND(k, _x, _y, --_r); \
95 ROUND(k, _y, _x, --_r); \
96 ROUND(k, _x, _y, --_r); \
97 ROUND(k, _y, _x, --_r); \
98 ROUND(k, _x, _y, --_r); \
99 ROUND(k, _y, _x, --_r); \
100 c = _y ^ k->p[0]; \
101 d = _x ^ k->p[1]; \
102 } while (0)
103
104 /*----- Low-level encryption interface ------------------------------------*/
105
106 /* --- @blowfish_init@ --- *
107 *
108 * Arguments: @blowfish_ctx *k@ = pointer to key block to fill in
109 * @const void *buf@ = pointer to buffer of key material
110 * @size_t sz@ = size of key material
111 *
112 * Returns: ---
113 *
114 * Use: Initializes a Blowfish key buffer. Blowfish accepts
115 * a more-or-less arbitrary size key.
116 */
117
118 void blowfish_init(blowfish_ctx *k, const void *buf, size_t sz)
119 {
120 KSZ_ASSERT(blowfish, sz);
121
122 /* --- Copy the initial value over --- */
123
124 memcpy(k, &ikey, sizeof(ikey));
125
126 /* --- Initialize the %$P$% array --- */
127
128 {
129 const octet *p = buf;
130 const octet *q = p + sz;
131 int i = 0, j = 0;
132 uint32 x = 0;
133
134 while (i < 18) {
135 x = (x << 8) | U8(*p++);
136 if (p >= q)
137 p = buf;
138 if (++j >= 4) {
139 k->p[i++] ^= x;
140 x = 0;
141 j = 0;
142 }
143 }
144
145 x = 0;
146 }
147
148 /* --- Now mangle the complete array of keys --- */
149
150 {
151 uint32 b[2];
152 int i;
153
154 b[0] = b[1] = 0;
155
156 for (i = 0; i < 18; i += 2) {
157 blowfish_eblk(k, b, b);
158 k->p[i] = b[0]; k->p[i + 1] = b[1];
159 }
160
161 for (i = 0; i < 256; i += 2) {
162 blowfish_eblk(k, b, b);
163 k->s0[i] = b[0]; k->s0[i + 1] = b[1];
164 }
165
166 for (i = 0; i < 256; i += 2) {
167 blowfish_eblk(k, b, b);
168 k->s1[i] = b[0]; k->s1[i + 1] = b[1];
169 }
170
171 for (i = 0; i < 256; i += 2) {
172 blowfish_eblk(k, b, b);
173 k->s2[i] = b[0]; k->s2[i + 1] = b[1];
174 }
175
176 for (i = 0; i < 256; i += 2) {
177 blowfish_eblk(k, b, b);
178 k->s3[i] = b[0]; k->s3[i + 1] = b[1];
179 }
180
181 BURN(b);
182 }
183 }
184
185 /* --- @blowfish_eblk@, @blowfish_dblk@ --- *
186 *
187 * Arguments: @const blowfish_ctx *k@ = pointer to key block
188 * @const uint32 s[2]@ = pointer to source block
189 * @uint32 d[2]@ = pointer to destination block
190 *
191 * Returns: ---
192 *
193 * Use: Low-level block encryption and decryption.
194 */
195
196 void blowfish_eblk(const blowfish_ctx *k, const uint32 *s, uint32 *d)
197 {
198 EBLK(k, s[0], s[1], d[0], d[1]);
199 }
200
201 void blowfish_dblk(const blowfish_ctx *k, const uint32 *s, uint32 *d)
202 {
203 DBLK(k, s[0], s[1], d[0], d[1]);
204 }
205
206 BLKC_TEST(BLOWFISH, blowfish)
207
208 /*----- That's all, folks -------------------------------------------------*/
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)