d03ab969 |
1 | /* -*-c-*- |
2 | * |
4e66da02 |
3 | * $Id: blowfish.c,v 1.3 2004/04/02 01:03:49 mdw Exp $ |
d03ab969 |
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 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: blowfish.c,v $ |
4e66da02 |
33 | * Revision 1.3 2004/04/02 01:03:49 mdw |
34 | * Miscellaneous constification. |
35 | * |
2e6a5ab5 |
36 | * Revision 1.2 2000/06/17 10:47:56 mdw |
37 | * Tidy round function a little. Support new key size interface. |
38 | * |
d03ab969 |
39 | * Revision 1.1 1999/09/03 08:41:11 mdw |
40 | * Initial import. |
41 | * |
42 | */ |
43 | |
44 | /*----- Header files ------------------------------------------------------*/ |
45 | |
46 | #include <mLib/bits.h> |
47 | |
48 | #include "blowfish.h" |
2e6a5ab5 |
49 | #include "blowfish-tab.h" |
d03ab969 |
50 | #include "blkc.h" |
2e6a5ab5 |
51 | #include "gcipher.h" |
d03ab969 |
52 | #include "paranoia.h" |
53 | |
54 | /*----- Global variables --------------------------------------------------*/ |
55 | |
4e66da02 |
56 | static const blowfish_ctx ikey = BLOWFISH_IKEY; |
d03ab969 |
57 | |
2e6a5ab5 |
58 | const octet blowfish_keysz[] = { KSZ_RANGE, BLOWFISH_KEYSZ, 1, 56, 1 }; |
59 | |
d03ab969 |
60 | /*----- Macros ------------------------------------------------------------*/ |
61 | |
2e6a5ab5 |
62 | #define ROUND(k, x, y, r) do { \ |
63 | x ^= *r; \ |
64 | y ^= ((k->s0[U8(x >> 24)] + \ |
65 | k->s1[U8(x >> 16)]) ^ \ |
66 | k->s2[U8(x >> 8)]) + \ |
67 | k->s3[U8(x >> 0)]; \ |
68 | } while (0) |
d03ab969 |
69 | |
70 | #define EBLK(k, a, b, c, d) do { \ |
2e6a5ab5 |
71 | const uint32 *_r = k->p; \ |
72 | uint32 _x = a; \ |
73 | uint32 _y = b; \ |
74 | ROUND(k, _x, _y, _r++); \ |
75 | ROUND(k, _y, _x, _r++); \ |
76 | ROUND(k, _x, _y, _r++); \ |
77 | ROUND(k, _y, _x, _r++); \ |
78 | ROUND(k, _x, _y, _r++); \ |
79 | ROUND(k, _y, _x, _r++); \ |
80 | ROUND(k, _x, _y, _r++); \ |
81 | ROUND(k, _y, _x, _r++); \ |
82 | ROUND(k, _x, _y, _r++); \ |
83 | ROUND(k, _y, _x, _r++); \ |
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 | c = _y ^ k->p[17]; \ |
91 | d = _x ^ k->p[16]; \ |
d03ab969 |
92 | } while (0) |
93 | |
94 | #define DBLK(k, a, b, c, d) do { \ |
2e6a5ab5 |
95 | const uint32 *_r = k->p + 18; \ |
96 | uint32 _x = a; \ |
97 | uint32 _y = b; \ |
98 | ROUND(k, _x, _y, --_r); \ |
99 | ROUND(k, _y, _x, --_r); \ |
100 | ROUND(k, _x, _y, --_r); \ |
101 | ROUND(k, _y, _x, --_r); \ |
102 | ROUND(k, _x, _y, --_r); \ |
103 | ROUND(k, _y, _x, --_r); \ |
104 | ROUND(k, _x, _y, --_r); \ |
105 | ROUND(k, _y, _x, --_r); \ |
106 | ROUND(k, _x, _y, --_r); \ |
107 | ROUND(k, _y, _x, --_r); \ |
108 | ROUND(k, _x, _y, --_r); \ |
109 | ROUND(k, _y, _x, --_r); \ |
110 | ROUND(k, _x, _y, --_r); \ |
111 | ROUND(k, _y, _x, --_r); \ |
112 | ROUND(k, _x, _y, --_r); \ |
113 | ROUND(k, _y, _x, --_r); \ |
114 | c = _y ^ k->p[0]; \ |
115 | d = _x ^ k->p[1]; \ |
d03ab969 |
116 | } while (0) |
117 | |
118 | /*----- Low-level encryption interface ------------------------------------*/ |
119 | |
120 | /* --- @blowfish_init@ --- * |
121 | * |
122 | * Arguments: @blowfish_ctx *k@ = pointer to key block to fill in |
123 | * @const void *buf@ = pointer to buffer of key material |
124 | * @size_t sz@ = size of key material |
125 | * |
126 | * Returns: --- |
127 | * |
128 | * Use: Initializes a Blowfish key buffer. Blowfish accepts |
129 | * a more-or-less arbitrary size key. |
130 | */ |
131 | |
132 | void blowfish_init(blowfish_ctx *k, const void *buf, size_t sz) |
133 | { |
2e6a5ab5 |
134 | KSZ_ASSERT(blowfish, sz); |
135 | |
d03ab969 |
136 | /* --- Copy the initial value over --- */ |
137 | |
138 | memcpy(k, &ikey, sizeof(ikey)); |
139 | |
140 | /* --- Initialize the %$P$% array --- */ |
141 | |
142 | { |
143 | const octet *p = buf; |
144 | const octet *q = p + sz; |
145 | int i = 0, j = 0; |
146 | uint32 x = 0; |
147 | |
148 | while (i < 18) { |
149 | x = (x << 8) | U8(*p++); |
150 | if (p >= q) |
151 | p = buf; |
152 | if (++j >= 4) { |
153 | k->p[i++] ^= x; |
154 | x = 0; |
155 | j = 0; |
156 | } |
157 | } |
158 | |
159 | x = 0; |
160 | } |
161 | |
162 | /* --- Now mangle the complete array of keys --- */ |
163 | |
164 | { |
165 | uint32 b[2]; |
166 | int i; |
167 | |
168 | b[0] = b[1] = 0; |
169 | |
170 | for (i = 0; i < 18; i += 2) { |
171 | blowfish_eblk(k, b, b); |
172 | k->p[i] = b[0]; k->p[i + 1] = b[1]; |
173 | } |
174 | |
175 | for (i = 0; i < 256; i += 2) { |
176 | blowfish_eblk(k, b, b); |
177 | k->s0[i] = b[0]; k->s0[i + 1] = b[1]; |
178 | } |
179 | |
180 | for (i = 0; i < 256; i += 2) { |
181 | blowfish_eblk(k, b, b); |
182 | k->s1[i] = b[0]; k->s1[i + 1] = b[1]; |
183 | } |
184 | |
185 | for (i = 0; i < 256; i += 2) { |
186 | blowfish_eblk(k, b, b); |
187 | k->s2[i] = b[0]; k->s2[i + 1] = b[1]; |
188 | } |
189 | |
190 | for (i = 0; i < 256; i += 2) { |
191 | blowfish_eblk(k, b, b); |
192 | k->s3[i] = b[0]; k->s3[i + 1] = b[1]; |
193 | } |
194 | |
195 | BURN(b); |
196 | } |
197 | } |
198 | |
199 | /* --- @blowfish_eblk@, @blowfish_dblk@ --- * |
200 | * |
201 | * Arguments: @const blowfish_ctx *k@ = pointer to key block |
202 | * @const uint32 s[2]@ = pointer to source block |
203 | * @uint32 d[2]@ = pointer to destination block |
204 | * |
205 | * Returns: --- |
206 | * |
207 | * Use: Low-level block encryption and decryption. |
208 | */ |
209 | |
210 | void blowfish_eblk(const blowfish_ctx *k, const uint32 *s, uint32 *d) |
211 | { |
212 | EBLK(k, s[0], s[1], d[0], d[1]); |
213 | } |
214 | |
215 | void blowfish_dblk(const blowfish_ctx *k, const uint32 *s, uint32 *d) |
216 | { |
217 | DBLK(k, s[0], s[1], d[0], d[1]); |
218 | } |
219 | |
220 | BLKC_TEST(BLOWFISH, blowfish) |
221 | |
222 | /*----- That's all, folks -------------------------------------------------*/ |