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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: blowfish.c,v 1.2 2000/06/17 10:47:56 mdw Exp $ |
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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 $ |
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33 | * Revision 1.2 2000/06/17 10:47:56 mdw |
34 | * Tidy round function a little. Support new key size interface. |
35 | * |
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36 | * Revision 1.1 1999/09/03 08:41:11 mdw |
37 | * Initial import. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <mLib/bits.h> |
44 | |
45 | #include "blowfish.h" |
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46 | #include "blowfish-tab.h" |
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47 | #include "blkc.h" |
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48 | #include "gcipher.h" |
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49 | #include "paranoia.h" |
50 | |
51 | /*----- Global variables --------------------------------------------------*/ |
52 | |
53 | static blowfish_ctx ikey = BLOWFISH_IKEY; |
54 | |
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55 | const octet blowfish_keysz[] = { KSZ_RANGE, BLOWFISH_KEYSZ, 1, 56, 1 }; |
56 | |
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57 | /*----- Macros ------------------------------------------------------------*/ |
58 | |
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59 | #define ROUND(k, x, y, r) do { \ |
60 | x ^= *r; \ |
61 | y ^= ((k->s0[U8(x >> 24)] + \ |
62 | k->s1[U8(x >> 16)]) ^ \ |
63 | k->s2[U8(x >> 8)]) + \ |
64 | k->s3[U8(x >> 0)]; \ |
65 | } while (0) |
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66 | |
67 | #define EBLK(k, a, b, c, d) do { \ |
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68 | const uint32 *_r = k->p; \ |
69 | uint32 _x = a; \ |
70 | uint32 _y = b; \ |
71 | ROUND(k, _x, _y, _r++); \ |
72 | ROUND(k, _y, _x, _r++); \ |
73 | ROUND(k, _x, _y, _r++); \ |
74 | ROUND(k, _y, _x, _r++); \ |
75 | ROUND(k, _x, _y, _r++); \ |
76 | ROUND(k, _y, _x, _r++); \ |
77 | ROUND(k, _x, _y, _r++); \ |
78 | ROUND(k, _y, _x, _r++); \ |
79 | ROUND(k, _x, _y, _r++); \ |
80 | ROUND(k, _y, _x, _r++); \ |
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 | c = _y ^ k->p[17]; \ |
88 | d = _x ^ k->p[16]; \ |
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89 | } while (0) |
90 | |
91 | #define DBLK(k, a, b, c, d) do { \ |
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92 | const uint32 *_r = k->p + 18; \ |
93 | uint32 _x = a; \ |
94 | uint32 _y = b; \ |
95 | ROUND(k, _x, _y, --_r); \ |
96 | ROUND(k, _y, _x, --_r); \ |
97 | ROUND(k, _x, _y, --_r); \ |
98 | ROUND(k, _y, _x, --_r); \ |
99 | ROUND(k, _x, _y, --_r); \ |
100 | ROUND(k, _y, _x, --_r); \ |
101 | ROUND(k, _x, _y, --_r); \ |
102 | ROUND(k, _y, _x, --_r); \ |
103 | ROUND(k, _x, _y, --_r); \ |
104 | ROUND(k, _y, _x, --_r); \ |
105 | ROUND(k, _x, _y, --_r); \ |
106 | ROUND(k, _y, _x, --_r); \ |
107 | ROUND(k, _x, _y, --_r); \ |
108 | ROUND(k, _y, _x, --_r); \ |
109 | ROUND(k, _x, _y, --_r); \ |
110 | ROUND(k, _y, _x, --_r); \ |
111 | c = _y ^ k->p[0]; \ |
112 | d = _x ^ k->p[1]; \ |
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113 | } while (0) |
114 | |
115 | /*----- Low-level encryption interface ------------------------------------*/ |
116 | |
117 | /* --- @blowfish_init@ --- * |
118 | * |
119 | * Arguments: @blowfish_ctx *k@ = pointer to key block to fill in |
120 | * @const void *buf@ = pointer to buffer of key material |
121 | * @size_t sz@ = size of key material |
122 | * |
123 | * Returns: --- |
124 | * |
125 | * Use: Initializes a Blowfish key buffer. Blowfish accepts |
126 | * a more-or-less arbitrary size key. |
127 | */ |
128 | |
129 | void blowfish_init(blowfish_ctx *k, const void *buf, size_t sz) |
130 | { |
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131 | KSZ_ASSERT(blowfish, sz); |
132 | |
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133 | /* --- Copy the initial value over --- */ |
134 | |
135 | memcpy(k, &ikey, sizeof(ikey)); |
136 | |
137 | /* --- Initialize the %$P$% array --- */ |
138 | |
139 | { |
140 | const octet *p = buf; |
141 | const octet *q = p + sz; |
142 | int i = 0, j = 0; |
143 | uint32 x = 0; |
144 | |
145 | while (i < 18) { |
146 | x = (x << 8) | U8(*p++); |
147 | if (p >= q) |
148 | p = buf; |
149 | if (++j >= 4) { |
150 | k->p[i++] ^= x; |
151 | x = 0; |
152 | j = 0; |
153 | } |
154 | } |
155 | |
156 | x = 0; |
157 | } |
158 | |
159 | /* --- Now mangle the complete array of keys --- */ |
160 | |
161 | { |
162 | uint32 b[2]; |
163 | int i; |
164 | |
165 | b[0] = b[1] = 0; |
166 | |
167 | for (i = 0; i < 18; i += 2) { |
168 | blowfish_eblk(k, b, b); |
169 | k->p[i] = b[0]; k->p[i + 1] = b[1]; |
170 | } |
171 | |
172 | for (i = 0; i < 256; i += 2) { |
173 | blowfish_eblk(k, b, b); |
174 | k->s0[i] = b[0]; k->s0[i + 1] = b[1]; |
175 | } |
176 | |
177 | for (i = 0; i < 256; i += 2) { |
178 | blowfish_eblk(k, b, b); |
179 | k->s1[i] = b[0]; k->s1[i + 1] = b[1]; |
180 | } |
181 | |
182 | for (i = 0; i < 256; i += 2) { |
183 | blowfish_eblk(k, b, b); |
184 | k->s2[i] = b[0]; k->s2[i + 1] = b[1]; |
185 | } |
186 | |
187 | for (i = 0; i < 256; i += 2) { |
188 | blowfish_eblk(k, b, b); |
189 | k->s3[i] = b[0]; k->s3[i + 1] = b[1]; |
190 | } |
191 | |
192 | BURN(b); |
193 | } |
194 | } |
195 | |
196 | /* --- @blowfish_eblk@, @blowfish_dblk@ --- * |
197 | * |
198 | * Arguments: @const blowfish_ctx *k@ = pointer to key block |
199 | * @const uint32 s[2]@ = pointer to source block |
200 | * @uint32 d[2]@ = pointer to destination block |
201 | * |
202 | * Returns: --- |
203 | * |
204 | * Use: Low-level block encryption and decryption. |
205 | */ |
206 | |
207 | void blowfish_eblk(const blowfish_ctx *k, const uint32 *s, uint32 *d) |
208 | { |
209 | EBLK(k, s[0], s[1], d[0], d[1]); |
210 | } |
211 | |
212 | void blowfish_dblk(const blowfish_ctx *k, const uint32 *s, uint32 *d) |
213 | { |
214 | DBLK(k, s[0], s[1], d[0], d[1]); |
215 | } |
216 | |
217 | BLKC_TEST(BLOWFISH, blowfish) |
218 | |
219 | /*----- That's all, folks -------------------------------------------------*/ |