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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: icrypt.c,v 1.3 1997/09/26 09:14:58 mdw Exp $ |
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4 | * |
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5 | * Higher level encryption functions |
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6 | * |
7 | * (c) 1997 Mark Wooding |
8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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11 | * |
12 | * This file is part of `become' |
13 | * |
14 | * `Become' is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * `Become' 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 General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
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25 | * along with `become'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: icrypt.c,v $ |
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32 | * Revision 1.3 1997/09/26 09:14:58 mdw |
33 | * Merged blowfish branch into trunk. |
34 | * |
35 | * Revision 1.2.2.1 1997/09/26 09:08:07 mdw |
36 | * Use the Blowfish encryption algorithm instead of IDEA. This is partly |
37 | * because I prefer Blowfish (without any particularly strong evidence) but |
38 | * mainly because IDEA is patented and Blowfish isn't. |
39 | * |
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40 | * Revision 1.2 1997/08/04 10:24:22 mdw |
41 | * Sources placed under CVS control. |
42 | * |
43 | * Revision 1.1 1997/07/21 13:47:49 mdw |
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44 | * Initial revision |
45 | * |
46 | */ |
47 | |
48 | /*----- Header files ------------------------------------------------------*/ |
49 | |
50 | /* --- ANSI headers --- */ |
51 | |
52 | #include <stdio.h> |
53 | #include <string.h> |
54 | #include <stdlib.h> |
55 | |
56 | /* --- Local headers --- */ |
57 | |
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58 | #include "blowfish.h" |
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59 | #include "config.h" |
60 | #include "icrypt.h" |
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61 | |
62 | /*----- Main code ---------------------------------------------------------*/ |
63 | |
64 | /* --- @icrypt_init@ --- * |
65 | * |
66 | * Arguments: @icrypt_job *j@ = pointer to job context block |
67 | * @unsigned char *k@ = pointer to key data |
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68 | * @size_t sz@ = size of the key data |
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69 | * @const unsigned char *iv@ = pointer to IV |
70 | * |
71 | * Returns: --- |
72 | * |
73 | * Use: Primes the context block ready for encryption. |
74 | */ |
75 | |
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76 | void icrypt_init(icrypt_job *j, unsigned char *k, |
77 | size_t sz, const unsigned char *iv) |
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78 | { |
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79 | blowfish_setKey(&j->k, k, sz); |
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80 | if (iv) |
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81 | memcpy(j->iv, iv, BLOWFISH_BLKSIZE); |
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82 | else |
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83 | memset(j->iv, 0, BLOWFISH_BLKSIZE); |
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84 | j->i = 8; |
85 | } |
86 | |
87 | /* --- @icrypt_encrypt@ --- * |
88 | * |
89 | * Arguments: @icrypt_job *j@ = job handle |
90 | * @const void *src@ = pointer to source buffer |
91 | * @void *dest@ = pointer to destination buffer |
92 | * @size_t sz@ = size of buffers to handle |
93 | * |
94 | * Returns: --- |
95 | * |
96 | * Use: Encrypts data from the source to the destination, using the |
97 | * key attached to the job handle. |
98 | */ |
99 | |
100 | void icrypt_encrypt(icrypt_job *j, const void *src, void *dest, size_t sz) |
101 | { |
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102 | const unsigned char *s = src; |
103 | unsigned char *d = dest; |
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104 | int i; |
105 | |
106 | /* --- First, use up bytes in the buffer --- */ |
107 | |
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108 | while (j->i < BLOWFISH_BLKSIZE && sz > 0) { |
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109 | *d++ = j->iv[j->i++] ^= *s++; |
110 | sz--; |
111 | } |
112 | if (!sz) return; |
113 | |
114 | /* --- Now encrypt larger chunks at a time --- */ |
115 | |
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116 | while (sz >= BLOWFISH_BLKSIZE) { |
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117 | |
118 | /* --- Freshen the IV --- */ |
119 | |
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120 | blowfish_encrypt(&j->k, j->iv, j->iv); |
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121 | |
122 | /* --- Now encrypt some more bytes --- */ |
123 | |
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124 | for (i = 0; i < BLOWFISH_BLKSIZE; i++) { |
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125 | *d++ = j->iv[i] ^= *s++; |
126 | } |
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127 | sz -= BLOWFISH_BLKSIZE; |
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128 | } |
129 | if (!sz) return; |
130 | |
131 | /* --- Do the tail-end bits --- */ |
132 | |
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133 | blowfish_encrypt(&j->k, j->iv, j->iv); |
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134 | j->i = 0; |
135 | while (sz) { |
136 | *d++ = j->iv[j->i++] ^= *s++; |
137 | sz--; |
138 | } |
139 | } |
140 | |
141 | /* --- @icrypt_decrypt@ --- * |
142 | * |
143 | * Arguments: @icrypt_job *j@ = job handle |
144 | * @const void *src@ = pointer to source buffer |
145 | * @void *dest@ = pointer to destination buffer |
146 | * @size_t sz@ = size of buffers to handle |
147 | * |
148 | * Returns: --- |
149 | * |
150 | * Use: Decrypts data from the source to the destination, using |
151 | * the key attached to the job handle. |
152 | */ |
153 | |
154 | void icrypt_decrypt(icrypt_job *j, const void *src, void *dest, size_t sz) |
155 | { |
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156 | unsigned const char *s = src; |
157 | unsigned char *d = dest; |
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158 | int i; |
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159 | unsigned char c; |
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160 | |
161 | /* --- First, use up bytes in the buffer --- */ |
162 | |
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163 | while (j->i < BLOWFISH_BLKSIZE && sz > 0) { |
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164 | c = *s++; |
165 | *d++ = j->iv[j->i] ^ c; |
166 | j->iv[j->i++] = c; |
167 | sz--; |
168 | } |
169 | if (!sz) return; |
170 | |
171 | /* --- Now encrypt larger chunks at a time --- */ |
172 | |
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173 | while (sz >= BLOWFISH_BLKSIZE) { |
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174 | |
175 | /* --- Freshen the IV --- */ |
176 | |
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177 | blowfish_encrypt(&j->k, j->iv, j->iv); |
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178 | |
179 | /* --- Now encrypt some more bytes --- */ |
180 | |
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181 | for (i = 0; i < BLOWFISH_BLKSIZE; i++) { |
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182 | c = *s++; |
183 | *d++ = j->iv[i] ^ c; |
184 | j->iv[i] = c; |
185 | } |
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186 | sz -= BLOWFISH_BLKSIZE; |
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187 | } |
188 | if (!sz) return; |
189 | |
190 | /* --- Do the tail-end bits --- */ |
191 | |
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192 | blowfish_encrypt(&j->k, j->iv, j->iv); |
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193 | j->i = 0; |
194 | while (sz) { |
195 | c = *s++; |
196 | *d++ = j->iv[j->i] ^ c; |
197 | j->iv[j->i++] = c; |
198 | sz--; |
199 | } |
200 | } |
201 | |
202 | /* --- @icrypt_reset@ --- * |
203 | * |
204 | * Arguments: @icrypt_job *j@ = pointer to job context block |
205 | * @unsigned char *k@ = pointer to key data, or zero for |
206 | * no change |
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207 | * @size_t sz@ = size of the key in bytes |
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208 | * @const unsigned char *iv@ = pointer to IV, or zero |
209 | * |
210 | * Returns: --- |
211 | * |
212 | * Use: Alters the context block. This can be used after recovery |
213 | * of a session key, for example. |
214 | */ |
215 | |
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216 | void icrypt_reset(icrypt_job *j, unsigned char *k, |
217 | size_t sz, const unsigned char *iv) |
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218 | { |
219 | if (k) |
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220 | blowfish_setKey(&j->k, k, sz); |
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221 | if (iv) |
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222 | memcpy(j->iv, iv, BLOWFISH_BLKSIZE); |
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223 | else { |
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224 | unsigned char b[BLOWFISH_BLKSIZE]; |
225 | int n = j->i, o = BLOWFISH_BLKSIZE - j->i; |
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226 | |
227 | memcpy(b, j->iv, sizeof(b)); |
228 | memcpy(j->iv, b + n, o); |
229 | memcpy(j->iv + o, b, n); |
230 | } |
231 | j->i = 8; |
232 | } |
233 | |
234 | /* --- @icrypt_saveIV@ --- * |
235 | * |
236 | * Arguments: @icrypt_job *j@ = pointer to job context block |
237 | * @unsigned char *iv@ = where to store the IV |
238 | * |
239 | * Returns: --- |
240 | * |
241 | * Use: Writes out the job's IV after munging it a little. |
242 | */ |
243 | |
244 | void icrypt_saveIV(icrypt_job *j, unsigned char *iv) |
245 | { |
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246 | int n = j->i, o = BLOWFISH_BLKSIZE - j->i; |
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247 | |
248 | memcpy(j->iv, iv + n, o); |
249 | memcpy(j->iv + o, iv, n); |
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250 | blowfish_encrypt(&j->k, iv, iv); |
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251 | } |
252 | |
253 | /*----- Test rig ----------------------------------------------------------*/ |
254 | |
255 | #ifdef TEST_RIG |
256 | |
257 | #include <errno.h> |
258 | #include <pwd.h> |
259 | #include <unistd.h> |
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260 | #include "crypt.h" |
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261 | #include "mdwopt.h" |
262 | #include "md5.h" |
263 | #include "utils.h" |
264 | |
265 | void icrypt(icrypt_job *j, |
266 | void (*proc)(icrypt_job *j, |
267 | const void *src, |
268 | void *dest, |
269 | size_t sz), |
270 | FILE *fp) |
271 | { |
272 | char buff[71]; |
273 | size_t r; |
274 | |
275 | for (;;) { |
276 | r = fread(buff, 1, sizeof(buff), fp); |
277 | if (!r) break; |
278 | proc(j, buff, buff, r); |
279 | fwrite(buff, 1, r, stdout); |
280 | } |
281 | } |
282 | |
283 | int main(int argc, char *argv[]) |
284 | { |
285 | icrypt_job j; |
286 | md5 md; |
287 | void (*proc)(icrypt_job *j, |
288 | const void *src, |
289 | void *dest, |
290 | size_t sz) = icrypt_encrypt; |
291 | |
292 | ego(argv[0]); |
293 | |
294 | for (;;) { |
295 | int i = getopt(argc, argv, "d"); |
296 | if (i < 0) |
297 | break; |
298 | if (i == 'd') |
299 | proc = icrypt_decrypt; |
300 | } |
301 | |
302 | { |
303 | char *pass = getpass("Password: "); |
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304 | unsigned char k[BLOWFISH_KEYSIZE]; |
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305 | md5_init(&md); |
306 | md5_buffer(&md, pass, strlen(pass)); |
307 | memset(pass, 0, strlen(pass)); |
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308 | md5_final(&md, k); |
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309 | |
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310 | icrypt_init(&j, k, BLOWFISH_KEYSIZE, 0); |
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311 | } |
312 | |
313 | if (optind >= argc) |
314 | icrypt(&j, proc, stdin); |
315 | |
316 | while (optind < argc) { |
317 | char *p = argv[optind++]; |
318 | if (strcmp(p, "-") == 0) |
319 | icrypt(&j, proc, stdin); |
320 | else { |
321 | FILE *fp = fopen(p, "rb"); |
322 | if (!fp) |
323 | die("couldn't open `%s': %s", p, strerror(errno)); |
324 | icrypt(&j, proc, fp); |
325 | fclose(fp); |
326 | } |
327 | } |
328 | |
329 | return (0); |
330 | } |
331 | |
332 | #endif |
333 | |
334 | /*----- That's all, folks -------------------------------------------------*/ |