| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: icrypt.c,v 1.2 1997/08/04 10:24:22 mdw Exp $ |
| 4 | * |
| 5 | * Higher level IDEA encryption |
| 6 | * |
| 7 | * (c) 1997 Mark Wooding |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 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 |
| 25 | * along with `become'; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: icrypt.c,v $ |
| 32 | * Revision 1.2 1997/08/04 10:24:22 mdw |
| 33 | * Sources placed under CVS control. |
| 34 | * |
| 35 | * Revision 1.1 1997/07/21 13:47:49 mdw |
| 36 | * Initial revision |
| 37 | * |
| 38 | */ |
| 39 | |
| 40 | /*----- Header files ------------------------------------------------------*/ |
| 41 | |
| 42 | /* --- ANSI headers --- */ |
| 43 | |
| 44 | #include <stdio.h> |
| 45 | #include <string.h> |
| 46 | #include <stdlib.h> |
| 47 | |
| 48 | /* --- Local headers --- */ |
| 49 | |
| 50 | #include "config.h" |
| 51 | #include "icrypt.h" |
| 52 | #include "idea.h" |
| 53 | |
| 54 | /*----- Main code ---------------------------------------------------------*/ |
| 55 | |
| 56 | /* --- @icrypt_init@ --- * |
| 57 | * |
| 58 | * Arguments: @icrypt_job *j@ = pointer to job context block |
| 59 | * @unsigned char *k@ = pointer to key data |
| 60 | * @const unsigned char *iv@ = pointer to IV |
| 61 | * |
| 62 | * Returns: --- |
| 63 | * |
| 64 | * Use: Primes the context block ready for encryption. |
| 65 | */ |
| 66 | |
| 67 | void icrypt_init(icrypt_job *j, unsigned char *k, const unsigned char *iv) |
| 68 | { |
| 69 | idea_ekeys(&j->k, k); |
| 70 | if (iv) |
| 71 | memcpy(j->iv, iv, IDEA_BLKSIZE); |
| 72 | else |
| 73 | memset(j->iv, 0, IDEA_BLKSIZE); |
| 74 | j->i = 8; |
| 75 | } |
| 76 | |
| 77 | /* --- @icrypt_encrypt@ --- * |
| 78 | * |
| 79 | * Arguments: @icrypt_job *j@ = job handle |
| 80 | * @const void *src@ = pointer to source buffer |
| 81 | * @void *dest@ = pointer to destination buffer |
| 82 | * @size_t sz@ = size of buffers to handle |
| 83 | * |
| 84 | * Returns: --- |
| 85 | * |
| 86 | * Use: Encrypts data from the source to the destination, using the |
| 87 | * key attached to the job handle. |
| 88 | */ |
| 89 | |
| 90 | void icrypt_encrypt(icrypt_job *j, const void *src, void *dest, size_t sz) |
| 91 | { |
| 92 | const char *s = src; |
| 93 | char *d = dest; |
| 94 | int i; |
| 95 | |
| 96 | /* --- First, use up bytes in the buffer --- */ |
| 97 | |
| 98 | while (j->i < IDEA_BLKSIZE && sz > 0) { |
| 99 | *d++ = j->iv[j->i++] ^= *s++; |
| 100 | sz--; |
| 101 | } |
| 102 | if (!sz) return; |
| 103 | |
| 104 | /* --- Now encrypt larger chunks at a time --- */ |
| 105 | |
| 106 | while (sz >= IDEA_BLKSIZE) { |
| 107 | |
| 108 | /* --- Freshen the IV --- */ |
| 109 | |
| 110 | idea_encrypt(&j->k, j->iv, j->iv); |
| 111 | |
| 112 | /* --- Now encrypt some more bytes --- */ |
| 113 | |
| 114 | for (i = 0; i < IDEA_BLKSIZE; i++) { |
| 115 | *d++ = j->iv[i] ^= *s++; |
| 116 | } |
| 117 | sz -= IDEA_BLKSIZE; |
| 118 | } |
| 119 | if (!sz) return; |
| 120 | |
| 121 | /* --- Do the tail-end bits --- */ |
| 122 | |
| 123 | idea_encrypt(&j->k, j->iv, j->iv); |
| 124 | j->i = 0; |
| 125 | while (sz) { |
| 126 | *d++ = j->iv[j->i++] ^= *s++; |
| 127 | sz--; |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | /* --- @icrypt_decrypt@ --- * |
| 132 | * |
| 133 | * Arguments: @icrypt_job *j@ = job handle |
| 134 | * @const void *src@ = pointer to source buffer |
| 135 | * @void *dest@ = pointer to destination buffer |
| 136 | * @size_t sz@ = size of buffers to handle |
| 137 | * |
| 138 | * Returns: --- |
| 139 | * |
| 140 | * Use: Decrypts data from the source to the destination, using |
| 141 | * the key attached to the job handle. |
| 142 | */ |
| 143 | |
| 144 | void icrypt_decrypt(icrypt_job *j, const void *src, void *dest, size_t sz) |
| 145 | { |
| 146 | const char *s = src; |
| 147 | char *d = dest; |
| 148 | int i; |
| 149 | char c; |
| 150 | |
| 151 | /* --- First, use up bytes in the buffer --- */ |
| 152 | |
| 153 | while (j->i < IDEA_BLKSIZE && sz > 0) { |
| 154 | c = *s++; |
| 155 | *d++ = j->iv[j->i] ^ c; |
| 156 | j->iv[j->i++] = c; |
| 157 | sz--; |
| 158 | } |
| 159 | if (!sz) return; |
| 160 | |
| 161 | /* --- Now encrypt larger chunks at a time --- */ |
| 162 | |
| 163 | while (sz >= IDEA_BLKSIZE) { |
| 164 | |
| 165 | /* --- Freshen the IV --- */ |
| 166 | |
| 167 | idea_encrypt(&j->k, j->iv, j->iv); |
| 168 | |
| 169 | /* --- Now encrypt some more bytes --- */ |
| 170 | |
| 171 | for (i = 0; i < IDEA_BLKSIZE; i++) { |
| 172 | c = *s++; |
| 173 | *d++ = j->iv[i] ^ c; |
| 174 | j->iv[i] = c; |
| 175 | } |
| 176 | sz -= IDEA_BLKSIZE; |
| 177 | } |
| 178 | if (!sz) return; |
| 179 | |
| 180 | /* --- Do the tail-end bits --- */ |
| 181 | |
| 182 | idea_encrypt(&j->k, j->iv, j->iv); |
| 183 | j->i = 0; |
| 184 | while (sz) { |
| 185 | c = *s++; |
| 186 | *d++ = j->iv[j->i] ^ c; |
| 187 | j->iv[j->i++] = c; |
| 188 | sz--; |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /* --- @icrypt_reset@ --- * |
| 193 | * |
| 194 | * Arguments: @icrypt_job *j@ = pointer to job context block |
| 195 | * @unsigned char *k@ = pointer to key data, or zero for |
| 196 | * no change |
| 197 | * @const unsigned char *iv@ = pointer to IV, or zero |
| 198 | * |
| 199 | * Returns: --- |
| 200 | * |
| 201 | * Use: Alters the context block. This can be used after recovery |
| 202 | * of a session key, for example. |
| 203 | */ |
| 204 | |
| 205 | void icrypt_reset(icrypt_job *j, unsigned char *k, const unsigned char *iv) |
| 206 | { |
| 207 | if (k) |
| 208 | idea_ekeys(&j->k, k); |
| 209 | if (iv) |
| 210 | memcpy(j->iv, iv, IDEA_BLKSIZE); |
| 211 | else { |
| 212 | unsigned char b[IDEA_BLKSIZE]; |
| 213 | int n = j->i, o = IDEA_BLKSIZE - j->i; |
| 214 | |
| 215 | memcpy(b, j->iv, sizeof(b)); |
| 216 | memcpy(j->iv, b + n, o); |
| 217 | memcpy(j->iv + o, b, n); |
| 218 | } |
| 219 | j->i = 8; |
| 220 | } |
| 221 | |
| 222 | /* --- @icrypt_saveIV@ --- * |
| 223 | * |
| 224 | * Arguments: @icrypt_job *j@ = pointer to job context block |
| 225 | * @unsigned char *iv@ = where to store the IV |
| 226 | * |
| 227 | * Returns: --- |
| 228 | * |
| 229 | * Use: Writes out the job's IV after munging it a little. |
| 230 | */ |
| 231 | |
| 232 | void icrypt_saveIV(icrypt_job *j, unsigned char *iv) |
| 233 | { |
| 234 | int n = j->i, o = IDEA_BLKSIZE - j->i; |
| 235 | |
| 236 | memcpy(j->iv, iv + n, o); |
| 237 | memcpy(j->iv + o, iv, n); |
| 238 | idea_encrypt(&j->k, iv, iv); |
| 239 | } |
| 240 | |
| 241 | /*----- Test rig ----------------------------------------------------------*/ |
| 242 | |
| 243 | #ifdef TEST_RIG |
| 244 | |
| 245 | #include <errno.h> |
| 246 | #include <pwd.h> |
| 247 | #include <unistd.h> |
| 248 | #include "mdwopt.h" |
| 249 | #include "md5.h" |
| 250 | #include "utils.h" |
| 251 | |
| 252 | void icrypt(icrypt_job *j, |
| 253 | void (*proc)(icrypt_job *j, |
| 254 | const void *src, |
| 255 | void *dest, |
| 256 | size_t sz), |
| 257 | FILE *fp) |
| 258 | { |
| 259 | char buff[71]; |
| 260 | size_t r; |
| 261 | |
| 262 | for (;;) { |
| 263 | r = fread(buff, 1, sizeof(buff), fp); |
| 264 | if (!r) break; |
| 265 | proc(j, buff, buff, r); |
| 266 | fwrite(buff, 1, r, stdout); |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | int main(int argc, char *argv[]) |
| 271 | { |
| 272 | icrypt_job j; |
| 273 | md5 md; |
| 274 | void (*proc)(icrypt_job *j, |
| 275 | const void *src, |
| 276 | void *dest, |
| 277 | size_t sz) = icrypt_encrypt; |
| 278 | |
| 279 | ego(argv[0]); |
| 280 | |
| 281 | for (;;) { |
| 282 | int i = getopt(argc, argv, "d"); |
| 283 | if (i < 0) |
| 284 | break; |
| 285 | if (i == 'd') |
| 286 | proc = icrypt_decrypt; |
| 287 | } |
| 288 | |
| 289 | { |
| 290 | char *pass = getpass("Password: "); |
| 291 | unsigned char k[IDEA_KEYSIZE]; |
| 292 | md5_init(&md); |
| 293 | md5_buffer(&md, pass, strlen(pass)); |
| 294 | memset(pass, 0, strlen(pass)); |
| 295 | md5_final(&md, k); |
| 296 | |
| 297 | icrypt_init(&j, k, 0); |
| 298 | } |
| 299 | |
| 300 | if (optind >= argc) |
| 301 | icrypt(&j, proc, stdin); |
| 302 | |
| 303 | while (optind < argc) { |
| 304 | char *p = argv[optind++]; |
| 305 | if (strcmp(p, "-") == 0) |
| 306 | icrypt(&j, proc, stdin); |
| 307 | else { |
| 308 | FILE *fp = fopen(p, "rb"); |
| 309 | if (!fp) |
| 310 | die("couldn't open `%s': %s", p, strerror(errno)); |
| 311 | icrypt(&j, proc, fp); |
| 312 | fclose(fp); |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | return (0); |
| 317 | } |
| 318 | |
| 319 | #endif |
| 320 | |
| 321 | /*----- That's all, folks -------------------------------------------------*/ |