| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: keygen.c,v 1.5 1998/01/12 16:46:05 mdw Exp $ |
| 4 | * |
| 5 | * Key generation |
| 6 | * |
| 7 | * (c) 1998 EBI |
| 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: keygen.c,v $ |
| 32 | * Revision 1.5 1998/01/12 16:46:05 mdw |
| 33 | * Fix copyright date. |
| 34 | * |
| 35 | * Revision 1.4 1997/12/08 15:29:27 mdw |
| 36 | * Major update: make random number sources configurable. Generate |
| 37 | * warnings if there isn't enough randomness available. |
| 38 | * |
| 39 | * Revision 1.3 1997/09/17 15:29:28 mdw |
| 40 | * Mix the noise from the key timings with some other environmental noise |
| 41 | * (obtained from `noise_acquire') for a little bit more randomness. |
| 42 | * |
| 43 | * Revision 1.2 1997/08/04 10:24:23 mdw |
| 44 | * Sources placed under CVS control. |
| 45 | * |
| 46 | * Revision 1.1 1997/07/21 13:47:48 mdw |
| 47 | * Initial revision |
| 48 | * |
| 49 | */ |
| 50 | |
| 51 | /*----- Header files ------------------------------------------------------*/ |
| 52 | |
| 53 | /* --- ANSI headers --- */ |
| 54 | |
| 55 | #include <ctype.h> |
| 56 | #include <errno.h> |
| 57 | #include <signal.h> |
| 58 | #include <stdio.h> |
| 59 | #include <stdlib.h> |
| 60 | #include <string.h> |
| 61 | |
| 62 | /* --- Unix headers --- */ |
| 63 | |
| 64 | #include <sys/types.h> |
| 65 | #include <sys/time.h> |
| 66 | #include <fcntl.h> |
| 67 | |
| 68 | #include <termios.h> |
| 69 | #include <unistd.h> |
| 70 | |
| 71 | /* --- Local headers --- */ |
| 72 | |
| 73 | #include "config.h" |
| 74 | #include "mdwopt.h" |
| 75 | #include "noise.h" |
| 76 | #include "rand.h" |
| 77 | #include "tx.h" |
| 78 | #include "utils.h" |
| 79 | |
| 80 | /*----- Static variables --------------------------------------------------*/ |
| 81 | |
| 82 | static struct termios kg__raw, kg__old; /* Terminal settings */ |
| 83 | static int kg__tty; /* File handle for the terminal */ |
| 84 | static FILE *kg__ttyfp; /* Stream pointer for terminal */ |
| 85 | static unsigned int kg__flags; /* Various interesting flags */ |
| 86 | |
| 87 | enum { |
| 88 | kgFlag__cbreak = 1 /* Terminal is in cbreak mode */ |
| 89 | }; |
| 90 | |
| 91 | /*----- Main code ---------------------------------------------------------*/ |
| 92 | |
| 93 | /* --- @kg__cbreak@ --- * |
| 94 | * |
| 95 | * Arguments: --- |
| 96 | * |
| 97 | * Returns: --- |
| 98 | * |
| 99 | * Use: Makes the terminal return characters as soon as they're |
| 100 | * asked for. |
| 101 | */ |
| 102 | |
| 103 | void kg__cbreak(void) |
| 104 | { |
| 105 | /* --- Don't do this if I don't have to --- */ |
| 106 | |
| 107 | if (kg__flags & kgFlag__cbreak) |
| 108 | return; |
| 109 | |
| 110 | /* --- Fetch the old attributes, and remember them --- */ |
| 111 | |
| 112 | if (tcgetattr(kg__tty, &kg__old)) |
| 113 | die("couldn't read terminal attributes: %s", strerror(errno)); |
| 114 | memcpy(&kg__raw, &kg__old, sizeof(kg__raw)); |
| 115 | |
| 116 | /* --- Now modify them for raw mode --- */ |
| 117 | |
| 118 | kg__raw.c_lflag &= ~(ICANON | ECHO); |
| 119 | kg__raw.c_cc[VTIME] = 0; |
| 120 | kg__raw.c_cc[VMIN] = 1; |
| 121 | |
| 122 | /* --- Remember the new state, and away we go --- */ |
| 123 | |
| 124 | kg__flags |= kgFlag__cbreak; |
| 125 | if (tcsetattr(kg__tty, TCSAFLUSH, &kg__raw)) |
| 126 | die("couldn't set terminal attributes: %s", strerror(errno)); |
| 127 | } |
| 128 | |
| 129 | /* --- @kg__crepair@ --- * |
| 130 | * |
| 131 | * Arguments: --- |
| 132 | * |
| 133 | * Returns: --- |
| 134 | * |
| 135 | * Use: Unbreaks a cbroken tty. Obvious, innit? |
| 136 | */ |
| 137 | |
| 138 | static void kg__crepair(void) |
| 139 | { |
| 140 | /* --- Don't do this if I don't have to --- */ |
| 141 | |
| 142 | if (~kg__flags & kgFlag__cbreak) |
| 143 | return; |
| 144 | |
| 145 | /* --- Reset the old attributes --- */ |
| 146 | |
| 147 | tcsetattr(kg__tty, TCSAFLUSH, &kg__old); |
| 148 | kg__flags &= ~kgFlag__cbreak; |
| 149 | } |
| 150 | |
| 151 | /* --- @kg__signal@ --- * |
| 152 | * |
| 153 | * Arguments: @int sig@ = signal number |
| 154 | * |
| 155 | * Returns: --- |
| 156 | * |
| 157 | * Use: Tidies up if I get a signal. |
| 158 | */ |
| 159 | |
| 160 | static void kg__signal(int sig) |
| 161 | { |
| 162 | kg__crepair(); |
| 163 | signal(sig, SIG_DFL); |
| 164 | raise(sig); |
| 165 | } |
| 166 | |
| 167 | /* --- @kgFmt__binary@ --- * |
| 168 | * |
| 169 | * Arguments: @unsigned char *k@ = pointer to key buffer |
| 170 | * @size_t bits@ = number of bits to write |
| 171 | * @FILE *fp@ = stream to write on |
| 172 | * |
| 173 | * Returns: --- |
| 174 | * |
| 175 | * Use: Writes bits on a stream. |
| 176 | */ |
| 177 | |
| 178 | static void kgFmt__binary(unsigned char *k, size_t bits, FILE *fp) |
| 179 | { |
| 180 | fwrite(k, 1, bits / 8, fp); |
| 181 | } |
| 182 | |
| 183 | /* --- @kgFmt__base64@ --- * |
| 184 | * |
| 185 | * Arguments: @unsigned char *k@ = pointer to key buffer |
| 186 | * @size_t bits@ = number of bits to write |
| 187 | * @FILE *fp@ = stream to write on |
| 188 | * |
| 189 | * Returns: --- |
| 190 | * |
| 191 | * Use: Writes bits on a stream in an encoded way. |
| 192 | */ |
| 193 | |
| 194 | static void kgFmt__base64(unsigned char *k, size_t bits, FILE *fp) |
| 195 | { |
| 196 | static const char xlt[64] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ" |
| 197 | "abcdefghijklmnopqrstuvwxyz" |
| 198 | "0123456789+/" }; |
| 199 | unsigned long b; |
| 200 | int ll = 0; |
| 201 | |
| 202 | while (bits > 24) { |
| 203 | b = ((k[0] & 0xffu) << 16) | ((k[1] & 0xffu) << 8) | (k[2] & 0xffu); |
| 204 | k += 3; |
| 205 | bits -= 24; |
| 206 | putc(xlt[(b >> 18) & 0x3fu], fp); |
| 207 | putc(xlt[(b >> 12) & 0x3fu], fp); |
| 208 | putc(xlt[(b >> 6) & 0x3fu], fp); |
| 209 | putc(xlt[(b >> 0) & 0x3fu], fp); |
| 210 | if ((ll += 4) > 70) { |
| 211 | putc('\n', fp); |
| 212 | ll = 0; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | b = 0; |
| 217 | switch (bits) { |
| 218 | case 24: |
| 219 | b = *k++ & 0xffu; |
| 220 | case 16: |
| 221 | b = (b << 8) | (*k++ & 0xffu); |
| 222 | case 8: |
| 223 | b = (b << 8) | (*k++ & 0xffu); |
| 224 | } |
| 225 | b <<= (24 - bits); |
| 226 | putc(xlt[(b >> 18) & 0x3fu], fp); |
| 227 | putc(xlt[(b >> 12) & 0x3fu], fp); |
| 228 | switch (bits) { |
| 229 | case 24: |
| 230 | putc(xlt[(b >> 6) & 0x3fu], fp); |
| 231 | putc(xlt[(b >> 0) & 0x3fu], fp); |
| 232 | break; |
| 233 | case 16: |
| 234 | putc(xlt[(b >> 6) & 0x3fu], fp); |
| 235 | putc('=', fp); |
| 236 | break; |
| 237 | case 8: |
| 238 | fputs("==", fp); |
| 239 | break; |
| 240 | } |
| 241 | |
| 242 | putc('\n', fp); |
| 243 | } |
| 244 | |
| 245 | /* --- @kg__gen@ --- * |
| 246 | * |
| 247 | * Arguments: @unsigned char *ui@ = pointer to array to fill in |
| 248 | * @size_t sz@ = number of bits to generate |
| 249 | * |
| 250 | * Returns: --- |
| 251 | * |
| 252 | * Use: Uses key timings to generate random numbers. Maybe. |
| 253 | */ |
| 254 | |
| 255 | static void kg__gen(unsigned char *ui, size_t sz) |
| 256 | { |
| 257 | int bits = 32 < sz ? 32 : sz; |
| 258 | size_t wsz = (sz + 31u) & ~31u; |
| 259 | unsigned long last, ldiff = 0; |
| 260 | unsigned long a = 0; |
| 261 | unsigned long fact = 1000000 / CLOCKS_PER_SEC; |
| 262 | |
| 263 | fprintf(kg__ttyfp, |
| 264 | "I need to get %lu random bits; I'll do this by timing your keypresses.\n" |
| 265 | "Please type some arbitrary text until I say `done'.\n", |
| 266 | (unsigned long)sz); |
| 267 | |
| 268 | { |
| 269 | struct timeval tv; |
| 270 | gettimeofday(&tv, 0); |
| 271 | last = tv.tv_usec / fact + tv.tv_sec * fact; |
| 272 | } |
| 273 | |
| 274 | while (sz) { |
| 275 | int useful; |
| 276 | uint_32 orr, xor; |
| 277 | |
| 278 | /* --- Print current status --- */ |
| 279 | |
| 280 | fprintf(kg__ttyfp, "\r%5lu...", (unsigned long)sz); |
| 281 | fflush(kg__ttyfp); |
| 282 | |
| 283 | /* --- Read the next character --- */ |
| 284 | |
| 285 | { |
| 286 | char buff[16]; |
| 287 | if (read(kg__tty, buff, sizeof(buff)) < 0) |
| 288 | die("couldn't read from terminal: %s", strerror(errno)); |
| 289 | } |
| 290 | |
| 291 | /* --- Fiddle with times --- * |
| 292 | * |
| 293 | * Read the time now. Turn it into 32 bits of useful information, and |
| 294 | * find the difference between that and the previous time. Compare this |
| 295 | * with the difference between the previous pair of keypresses. |
| 296 | */ |
| 297 | |
| 298 | { |
| 299 | struct timeval tv; |
| 300 | uint_32 n, nd; |
| 301 | |
| 302 | gettimeofday(&tv, 0); |
| 303 | n = tv.tv_usec / fact + tv.tv_sec * fact; |
| 304 | if (!ldiff) { |
| 305 | ldiff = n - last; |
| 306 | last = n; |
| 307 | continue; |
| 308 | } |
| 309 | nd = n - last; |
| 310 | orr = nd | ldiff; |
| 311 | xor = nd ^ ldiff; |
| 312 | D( printf("\nlast = %08lx, next = %08lx, ldiff = %08lx, nd = %08lx\n", |
| 313 | (unsigned long)last, (unsigned long)n, |
| 314 | (unsigned long)ldiff, (unsigned long)nd); |
| 315 | printf("xor = %08lx\n", (unsigned long)xor); ) |
| 316 | ldiff = nd; |
| 317 | last = n; |
| 318 | } |
| 319 | |
| 320 | /* --- Find the useful bits in this value --- * |
| 321 | * |
| 322 | * Find the least significant set bit in @bowl@ and chop it off. Then |
| 323 | * find the most significant set bit and chop that off two. The rest is |
| 324 | * probably interesting. |
| 325 | */ |
| 326 | |
| 327 | { |
| 328 | unsigned long i; |
| 329 | |
| 330 | if (!orr || !xor) |
| 331 | continue; /* erk! */ |
| 332 | |
| 333 | useful = 30; |
| 334 | |
| 335 | i = 0x80000000ul; |
| 336 | if (xor & i) { |
| 337 | while (i && (xor & i) != 0) { |
| 338 | i >>= 1; |
| 339 | useful--; |
| 340 | } |
| 341 | } else { |
| 342 | while (i && (xor & i) == 0) { |
| 343 | i >>= 1; |
| 344 | useful--; |
| 345 | } |
| 346 | } |
| 347 | xor &= ~-i; |
| 348 | |
| 349 | while ((orr & 1) == 0) { |
| 350 | useful--; |
| 351 | orr >>= 1; |
| 352 | xor >>= 1; |
| 353 | } |
| 354 | xor >>= 1; |
| 355 | |
| 356 | if (useful < 1) |
| 357 | continue; |
| 358 | } |
| 359 | |
| 360 | /* --- Now add the bits in the mixing bowl to my stash --- * |
| 361 | * |
| 362 | * There are two cases: |
| 363 | * |
| 364 | * 1. I have more bits than will fit into the accumulator. Then I must |
| 365 | * put as many bits into the accumulator as will fit, store the |
| 366 | * accumulator, and remove the spent bits. |
| 367 | * |
| 368 | * 2. I have too few bits to fit in the accumulator. Then shift them |
| 369 | * in and return. |
| 370 | */ |
| 371 | |
| 372 | while (sz && useful) { |
| 373 | |
| 374 | D( printf("got %i bits, need %i/%i: %8lx\n", |
| 375 | useful, bits, sz, (unsigned long)xor); ) |
| 376 | |
| 377 | if (useful >= bits) { |
| 378 | |
| 379 | D( printf("shifted acc = %08lx\n" |
| 380 | " new bits = %08lx\n" |
| 381 | " result = %08lx\n", |
| 382 | (unsigned long)(a << bits), |
| 383 | (unsigned long)(xor >> (useful - bits)), |
| 384 | (unsigned long)((a << bits) | (xor >> (useful - bits)))); ) |
| 385 | |
| 386 | a = (a << bits) | (xor >> (useful - bits)); |
| 387 | |
| 388 | sz -= bits; |
| 389 | wsz -= bits; |
| 390 | useful -= bits; |
| 391 | |
| 392 | if (sz == 0) { |
| 393 | a <<= wsz; |
| 394 | bits = 32 - wsz; |
| 395 | } else |
| 396 | bits = 32; |
| 397 | |
| 398 | while (bits > 0) { |
| 399 | D( printf("writing %02x\n", (a >> 24) & 0xffu); ) |
| 400 | *ui++ = (a >> 24) & 0xffu; |
| 401 | a <<= 8; |
| 402 | bits -= 8; |
| 403 | } |
| 404 | a = 0; |
| 405 | |
| 406 | bits = 32 < sz ? 32 : sz; |
| 407 | |
| 408 | } else { |
| 409 | |
| 410 | D( printf("shifted acc = %08lx\n" |
| 411 | " new bits = %08lx\n" |
| 412 | " result = %08lx\n", |
| 413 | (unsigned long)(a << useful), |
| 414 | (unsigned long)(xor), |
| 415 | (unsigned long)((a << useful) | (xor))); ) |
| 416 | a = (a << useful) | xor; |
| 417 | bits -= useful; |
| 418 | sz -= useful; |
| 419 | wsz -= useful; |
| 420 | useful = 0; |
| 421 | } |
| 422 | } |
| 423 | } |
| 424 | |
| 425 | fputs("\rDone! \n", kg__ttyfp); |
| 426 | putc('\a', kg__ttyfp); fflush(kg__ttyfp); |
| 427 | sleep(1); |
| 428 | } |
| 429 | |
| 430 | /* --- @main@ --- * |
| 431 | * |
| 432 | * Arguments: @int argc@ = number of arguments |
| 433 | * @char *argv[]@ = array of arguments |
| 434 | * |
| 435 | * Returns: Zero if it worked, nonzero if it didn't. |
| 436 | * |
| 437 | * Use: Generates random numbers from the keyboard. |
| 438 | */ |
| 439 | |
| 440 | int main(int argc, char *argv[]) |
| 441 | { |
| 442 | unsigned char *uip; |
| 443 | size_t sz = 128; |
| 444 | size_t keybits = 0; |
| 445 | unsigned f = 0; |
| 446 | const char *file = 0; |
| 447 | FILE *fp; |
| 448 | |
| 449 | enum { |
| 450 | f_envNoise = 1, |
| 451 | f_keyTimer = 2 |
| 452 | }; |
| 453 | |
| 454 | /* --- Formats table --- */ |
| 455 | |
| 456 | static struct { |
| 457 | const char *name; |
| 458 | void (*proc)(unsigned char *k, size_t bits, FILE *fp); |
| 459 | } format[] = { |
| 460 | { "tx", tx_putBits }, |
| 461 | { "hex", tx_putBits }, |
| 462 | { "binary", kgFmt__binary }, |
| 463 | { "base64", kgFmt__base64 }, |
| 464 | { 0, 0 } |
| 465 | }; |
| 466 | |
| 467 | void (*fmt)(unsigned char *, size_t, FILE *) = tx_putBits; |
| 468 | |
| 469 | /* --- Explain who I am --- */ |
| 470 | |
| 471 | ego(argv[0]); |
| 472 | |
| 473 | f |= f_envNoise | f_keyTimer; |
| 474 | |
| 475 | /* --- Read arguments --- */ |
| 476 | |
| 477 | for (;;) { |
| 478 | static struct option opts[] = { |
| 479 | { "help", 0, 0, 'h' }, |
| 480 | { "bits", gFlag_argReq, 0, 'b' }, |
| 481 | { "output", gFlag_argReq, 0, 'o' }, |
| 482 | { "format", gFlag_argReq, 0, 'f' }, |
| 483 | { "key-times", gFlag_negate|gFlag_argOpt, 0, 'k' }, |
| 484 | { "env-noise", gFlag_negate, 0, 'e' }, |
| 485 | { 0, 0, 0, 0 } |
| 486 | }; |
| 487 | |
| 488 | int i = mdwopt(argc, argv, "hb:o:f:k+::e+", opts, 0, 0, gFlag_negation); |
| 489 | |
| 490 | if (i < 0) |
| 491 | break; |
| 492 | switch (i) { |
| 493 | case 'h': |
| 494 | printf("" |
| 495 | "Usage: %s [-h] [-|+ek] [-b BITS] [-o FILE] [-f FORMAT]\n" |
| 496 | "\n" |
| 497 | "Generates BITS (by default, 128) random bits. The resulting number is\n" |
| 498 | "written to FILE, or standard output.\n\n" |
| 499 | "Randomness is taken from key-timings and environmental noise, although\n" |
| 500 | "you can disable either (or both) of these sources.\n\n" |
| 501 | "Options provided are:\n\n" |
| 502 | "-h, --help Display this help text\n" |
| 503 | "-b, --bits=BITS\t Generate BITS random bits instead of 128\n" |
| 504 | "-o, --output=FILE Write bits to FILE, not standard output\n" |
| 505 | "-f, --format=FORMAT Write bits in FORMAT:\n" |
| 506 | " tx, hex Hexadecimal\n" |
| 507 | " binary Raw binary\n" |
| 508 | " base64 Base64-encoded binary\n" |
| 509 | "-e, --[no-]env-noise Do [not] read environmental noise\n" |
| 510 | "-k, --[no-]key-times[=BITS] Do [not] read key timing information\n" |
| 511 | " (only read BITS bits from key timings)\n", |
| 512 | quis()); |
| 513 | exit(0); |
| 514 | break; |
| 515 | case 'b': |
| 516 | sz = atoi(optarg); |
| 517 | if (sz == 0) |
| 518 | die("bad number of bits (illegible or zero)"); |
| 519 | if (sz % 8) |
| 520 | die("can only generate a whole number of 8-bit bytes"); |
| 521 | break; |
| 522 | case 'o': |
| 523 | file = optarg; |
| 524 | break; |
| 525 | case 'f': |
| 526 | fmt = 0; |
| 527 | for (i = 0; format[i].name; i++) { |
| 528 | const char *p = format[i].name, *q = optarg; |
| 529 | for (;;) { |
| 530 | if (*q == 0) |
| 531 | break; |
| 532 | if (*p != *q) |
| 533 | break; |
| 534 | p++, q++; |
| 535 | } |
| 536 | if (!*q) { |
| 537 | if (fmt) |
| 538 | die("ambiguous format name: `%s'", optarg); |
| 539 | fmt = format[i].proc; |
| 540 | } |
| 541 | } |
| 542 | if (!fmt) |
| 543 | die("unknown format name: `%s'", optarg); |
| 544 | break; |
| 545 | case 'e': |
| 546 | f |= f_envNoise; |
| 547 | break; |
| 548 | case 'e' | gFlag_negated: |
| 549 | f &= ~f_envNoise; |
| 550 | break; |
| 551 | case 'k': |
| 552 | f |= f_keyTimer; |
| 553 | if (optarg) { |
| 554 | keybits = atoi(optarg); |
| 555 | if (keybits == 0) |
| 556 | die("bad number of bits (illegible or zero)"); |
| 557 | if (keybits % 8) |
| 558 | die("bad number of bits (must be multiple of 8)"); |
| 559 | } |
| 560 | else |
| 561 | keybits = 0; |
| 562 | break; |
| 563 | case 'k' | gFlag_negated: |
| 564 | f &= ~f_keyTimer; |
| 565 | break; |
| 566 | case '?': |
| 567 | exit(1); |
| 568 | break; |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | /* --- Check the sanity of this request --- */ |
| 573 | |
| 574 | { |
| 575 | size_t bits = 0; |
| 576 | |
| 577 | if (f & f_keyTimer) { |
| 578 | if (!keybits) |
| 579 | keybits = sz; |
| 580 | bits += keybits; |
| 581 | } |
| 582 | if (f & f_envNoise) |
| 583 | bits += 384; /* Estimate */ |
| 584 | |
| 585 | if (bits == 0) |
| 586 | die("no randomness sources given"); |
| 587 | if (bits < sz) |
| 588 | moan("warning: randomness may not be sufficiently high"); |
| 589 | } |
| 590 | |
| 591 | if (optind < argc) { |
| 592 | fprintf(stderr, "Usage: %s [-opts]\n", quis()); |
| 593 | exit(1); |
| 594 | } |
| 595 | |
| 596 | /* --- Allocate memory --- */ |
| 597 | |
| 598 | { |
| 599 | size_t buff = sz / 8; |
| 600 | if (f & f_keyTimer && keybits > sz) |
| 601 | buff = keybits / 8; |
| 602 | uip = xmalloc(buff); |
| 603 | } |
| 604 | |
| 605 | rand_clear(); |
| 606 | |
| 607 | /* --- Fetch randomness from key timings --- */ |
| 608 | |
| 609 | if (f & f_keyTimer) { |
| 610 | |
| 611 | /* --- Open the terminal --- * |
| 612 | * |
| 613 | * I'd like to be able to @fprintf@ to the terminal, so use @fopen@. |
| 614 | */ |
| 615 | |
| 616 | if ((kg__ttyfp = fopen("/dev/tty", "r+")) == 0) |
| 617 | die("couldn't open terminal: %s", strerror(errno)); |
| 618 | kg__tty = fileno(kg__ttyfp); |
| 619 | |
| 620 | /* --- Tidy up nicely if I die --- */ |
| 621 | |
| 622 | signal(SIGINT, kg__signal); |
| 623 | signal(SIGTERM, kg__signal); |
| 624 | atexit(kg__crepair); |
| 625 | |
| 626 | /* --- Put the terminal into cbreak, read the key, and restore --- */ |
| 627 | |
| 628 | kg__cbreak(); |
| 629 | kg__gen(uip, keybits); |
| 630 | kg__crepair(); |
| 631 | rand_add(uip, keybits / 8); |
| 632 | rand_churn(); |
| 633 | } |
| 634 | |
| 635 | /* --- Find some noise from the environment too --- */ |
| 636 | |
| 637 | if (f & f_envNoise) { |
| 638 | noise_acquire(); |
| 639 | rand_churn(); |
| 640 | } |
| 641 | |
| 642 | /* --- Now write the number and exit --- */ |
| 643 | |
| 644 | rand_extract(uip, sz / 8); |
| 645 | D( fputs("*** ", fp); tx_putBits(uip, sz, stdout); ) |
| 646 | |
| 647 | /* --- Open the output file, if one is specified --- */ |
| 648 | |
| 649 | if (file) { |
| 650 | int fd; |
| 651 | |
| 652 | /* --- Open the file oddly --- * |
| 653 | * |
| 654 | * There's a good reason for this. I want to be able to @fprintf@ (for |
| 655 | * the benefit of @tx_putWords@ mainly) but I also want to ensure that |
| 656 | * only the user has read permissions for the file. So I'll use @open@ |
| 657 | * with an appropriate mode and then @fdopen@ the file descriptor to |
| 658 | * get a stream. Yuk. |
| 659 | */ |
| 660 | |
| 661 | if ((fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, 0600)) < 0) |
| 662 | die("couldn't open output file: %s", strerror(errno)); |
| 663 | if ((fp = fdopen(fd, "w")) == 0) |
| 664 | die("couldn't attach stream to output file: %s", strerror(errno)); |
| 665 | } else |
| 666 | fp = stdout; |
| 667 | |
| 668 | fmt(uip, sz, fp); |
| 669 | if (file) |
| 670 | fclose(fp); |
| 671 | memset(uip, 0, sz / 8); /* Burn temporary buffer */ |
| 672 | rand_clear(); |
| 673 | return (0); |
| 674 | } |
| 675 | |
| 676 | /*----- That's all, folks -------------------------------------------------*/ |