Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
| 2 | |
| 3 | ssh-keygen.c |
| 4 | |
| 5 | Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 6 | |
| 7 | Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 8 | All rights reserved |
| 9 | |
| 10 | Created: Mon Mar 27 02:26:40 1995 ylo |
| 11 | |
| 12 | Identity and host key generation and maintenance. |
| 13 | |
| 14 | */ |
| 15 | |
| 16 | #include "includes.h" |
Damien Miller | 356a0b0 | 1999-11-08 15:30:59 +1100 | [diff] [blame] | 17 | RCSID("$Id: ssh-keygen.c,v 1.2 1999/11/08 04:30:59 damien Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 18 | |
| 19 | #include "rsa.h" |
| 20 | #include "ssh.h" |
| 21 | #include "xmalloc.h" |
| 22 | |
| 23 | /* Generated private key. */ |
| 24 | RSA *private_key; |
| 25 | |
| 26 | /* Generated public key. */ |
| 27 | RSA *public_key; |
| 28 | |
| 29 | /* Number of bits in the RSA key. This value can be changed on the command |
| 30 | line. */ |
| 31 | int bits = 1024; |
| 32 | |
| 33 | /* Flag indicating that we just want to change the passphrase. This can be |
| 34 | set on the command line. */ |
| 35 | int change_passphrase = 0; |
| 36 | |
| 37 | /* Flag indicating that we just want to change the comment. This can be set |
| 38 | on the command line. */ |
| 39 | int change_comment = 0; |
| 40 | |
| 41 | int quiet = 0; |
| 42 | |
| 43 | /* This is set to the identity file name if given on the command line. */ |
| 44 | char *identity_file = NULL; |
| 45 | |
| 46 | /* This is set to the passphrase if given on the command line. */ |
| 47 | char *identity_passphrase = NULL; |
| 48 | |
| 49 | /* This is set to the new passphrase if given on the command line. */ |
| 50 | char *identity_new_passphrase = NULL; |
| 51 | |
| 52 | /* This is set to the new comment if given on the command line. */ |
| 53 | char *identity_comment = NULL; |
| 54 | |
| 55 | /* Perform changing a passphrase. The argument is the passwd structure |
| 56 | for the current user. */ |
| 57 | |
| 58 | void |
| 59 | do_change_passphrase(struct passwd *pw) |
| 60 | { |
| 61 | char buf[1024], *comment; |
| 62 | char *old_passphrase, *passphrase1, *passphrase2; |
| 63 | struct stat st; |
| 64 | RSA *private_key; |
| 65 | |
| 66 | /* Read key file name. */ |
| 67 | if (identity_file != NULL) { |
| 68 | strncpy(buf, identity_file, sizeof(buf)); |
| 69 | buf[sizeof(buf) - 1] = '\0'; |
| 70 | } else { |
| 71 | printf("Enter file in which the key is ($HOME/%s): ", SSH_CLIENT_IDENTITY); |
| 72 | fflush(stdout); |
| 73 | if (fgets(buf, sizeof(buf), stdin) == NULL) |
| 74 | exit(1); |
| 75 | if (strchr(buf, '\n')) |
| 76 | *strchr(buf, '\n') = 0; |
| 77 | if (strcmp(buf, "") == 0) |
| 78 | snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, SSH_CLIENT_IDENTITY); |
| 79 | } |
| 80 | |
| 81 | /* Check if the file exists. */ |
| 82 | if (stat(buf, &st) < 0) |
| 83 | { |
| 84 | perror(buf); |
| 85 | exit(1); |
| 86 | } |
| 87 | |
| 88 | /* Try to load the public key from the file the verify that it is |
| 89 | readable and of the proper format. */ |
| 90 | public_key = RSA_new(); |
| 91 | if (!load_public_key(buf, public_key, NULL)) |
| 92 | { |
| 93 | printf("%s is not a valid key file.\n", buf); |
| 94 | exit(1); |
| 95 | } |
| 96 | /* Clear the public key since we are just about to load the whole file. */ |
| 97 | RSA_free(public_key); |
| 98 | |
| 99 | /* Try to load the file with empty passphrase. */ |
| 100 | private_key = RSA_new(); |
| 101 | if (!load_private_key(buf, "", private_key, &comment)) { |
| 102 | /* Read passphrase from the user. */ |
| 103 | if (identity_passphrase) |
| 104 | old_passphrase = xstrdup(identity_passphrase); |
| 105 | else |
| 106 | old_passphrase = read_passphrase("Enter old passphrase: ", 1); |
| 107 | /* Try to load using the passphrase. */ |
| 108 | if (!load_private_key(buf, old_passphrase, private_key, &comment)) |
| 109 | { |
| 110 | memset(old_passphrase, 0, strlen(old_passphrase)); |
| 111 | xfree(old_passphrase); |
| 112 | printf("Bad passphrase.\n"); |
| 113 | exit(1); |
| 114 | } |
| 115 | /* Destroy the passphrase. */ |
| 116 | memset(old_passphrase, 0, strlen(old_passphrase)); |
| 117 | xfree(old_passphrase); |
| 118 | } |
| 119 | printf("Key has comment '%s'\n", comment); |
Damien Miller | 356a0b0 | 1999-11-08 15:30:59 +1100 | [diff] [blame] | 120 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 121 | /* Ask the new passphrase (twice). */ |
| 122 | if (identity_new_passphrase) |
| 123 | { |
| 124 | passphrase1 = xstrdup(identity_new_passphrase); |
| 125 | passphrase2 = NULL; |
| 126 | } |
| 127 | else |
| 128 | { |
| 129 | passphrase1 = |
| 130 | read_passphrase("Enter new passphrase (empty for no passphrase): ", 1); |
| 131 | passphrase2 = read_passphrase("Enter same passphrase again: ", 1); |
| 132 | |
| 133 | /* Verify that they are the same. */ |
| 134 | if (strcmp(passphrase1, passphrase2) != 0) |
| 135 | { |
| 136 | memset(passphrase1, 0, strlen(passphrase1)); |
| 137 | memset(passphrase2, 0, strlen(passphrase2)); |
| 138 | xfree(passphrase1); |
| 139 | xfree(passphrase2); |
| 140 | printf("Pass phrases do not match. Try again.\n"); |
| 141 | exit(1); |
| 142 | } |
| 143 | /* Destroy the other copy. */ |
| 144 | memset(passphrase2, 0, strlen(passphrase2)); |
| 145 | xfree(passphrase2); |
| 146 | } |
| 147 | |
| 148 | /* Save the file using the new passphrase. */ |
| 149 | if (!save_private_key(buf, passphrase1, private_key, comment)) |
| 150 | { |
| 151 | printf("Saving the key failed: %s: %s.\n", |
| 152 | buf, strerror(errno)); |
| 153 | memset(passphrase1, 0, strlen(passphrase1)); |
| 154 | xfree(passphrase1); |
| 155 | RSA_free(private_key); |
| 156 | xfree(comment); |
| 157 | exit(1); |
| 158 | } |
| 159 | /* Destroy the passphrase and the copy of the key in memory. */ |
| 160 | memset(passphrase1, 0, strlen(passphrase1)); |
| 161 | xfree(passphrase1); |
| 162 | RSA_free(private_key); /* Destroys contents */ |
| 163 | xfree(comment); |
| 164 | |
| 165 | printf("Your identification has been saved with the new passphrase.\n"); |
| 166 | exit(0); |
| 167 | } |
| 168 | |
| 169 | /* Change the comment of a private key file. */ |
| 170 | |
| 171 | void |
| 172 | do_change_comment(struct passwd *pw) |
| 173 | { |
| 174 | char buf[1024], new_comment[1024], *comment; |
| 175 | RSA *private_key; |
| 176 | char *passphrase; |
| 177 | struct stat st; |
| 178 | FILE *f; |
| 179 | char *tmpbuf; |
| 180 | |
| 181 | /* Read key file name. */ |
| 182 | if (identity_file) |
| 183 | { |
| 184 | strncpy(buf, identity_file, sizeof(buf)); |
| 185 | buf[sizeof(buf) - 1] = '\0'; |
| 186 | } |
| 187 | else |
| 188 | { |
| 189 | printf("Enter file in which the key is ($HOME/%s): ", |
| 190 | SSH_CLIENT_IDENTITY); |
| 191 | fflush(stdout); |
| 192 | if (fgets(buf, sizeof(buf), stdin) == NULL) |
| 193 | exit(1); |
| 194 | if (strchr(buf, '\n')) |
| 195 | *strchr(buf, '\n') = 0; |
| 196 | if (strcmp(buf, "") == 0) |
| 197 | snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, SSH_CLIENT_IDENTITY); |
| 198 | } |
| 199 | |
| 200 | /* Check if the file exists. */ |
| 201 | if (stat(buf, &st) < 0) |
| 202 | { |
| 203 | perror(buf); |
| 204 | exit(1); |
| 205 | } |
| 206 | |
| 207 | /* Try to load the public key from the file the verify that it is |
| 208 | readable and of the proper format. */ |
| 209 | public_key = RSA_new(); |
| 210 | if (!load_public_key(buf, public_key, NULL)) |
| 211 | { |
| 212 | printf("%s is not a valid key file.\n", buf); |
| 213 | exit(1); |
| 214 | } |
| 215 | |
| 216 | private_key = RSA_new(); |
| 217 | /* Try to load the file with empty passphrase. */ |
| 218 | if (load_private_key(buf, "", private_key, &comment)) |
| 219 | passphrase = xstrdup(""); |
| 220 | else |
| 221 | { |
| 222 | /* Read passphrase from the user. */ |
| 223 | if (identity_passphrase) |
| 224 | passphrase = xstrdup(identity_passphrase); |
| 225 | else |
| 226 | if (identity_new_passphrase) |
| 227 | passphrase = xstrdup(identity_new_passphrase); |
| 228 | else |
| 229 | passphrase = read_passphrase("Enter passphrase: ", 1); |
| 230 | /* Try to load using the passphrase. */ |
| 231 | if (!load_private_key(buf, passphrase, private_key, &comment)) |
| 232 | { |
| 233 | memset(passphrase, 0, strlen(passphrase)); |
| 234 | xfree(passphrase); |
| 235 | printf("Bad passphrase.\n"); |
| 236 | exit(1); |
| 237 | } |
| 238 | } |
| 239 | printf("Key now has comment '%s'\n", comment); |
| 240 | |
| 241 | if (identity_comment) |
| 242 | { |
| 243 | strncpy(new_comment, identity_comment, sizeof(new_comment)); |
| 244 | new_comment[sizeof(new_comment) - 1] = '\0'; |
| 245 | } |
| 246 | else |
| 247 | { |
| 248 | printf("Enter new comment: "); |
| 249 | fflush(stdout); |
| 250 | if (!fgets(new_comment, sizeof(new_comment), stdin)) |
| 251 | { |
| 252 | memset(passphrase, 0, strlen(passphrase)); |
| 253 | RSA_free(private_key); |
| 254 | exit(1); |
| 255 | } |
| 256 | |
| 257 | /* Remove terminating newline from comment. */ |
| 258 | if (strchr(new_comment, '\n')) |
| 259 | *strchr(new_comment, '\n') = 0; |
| 260 | } |
| 261 | |
| 262 | /* Save the file using the new passphrase. */ |
| 263 | if (!save_private_key(buf, passphrase, private_key, new_comment)) |
| 264 | { |
| 265 | printf("Saving the key failed: %s: %s.\n", |
| 266 | buf, strerror(errno)); |
| 267 | memset(passphrase, 0, strlen(passphrase)); |
| 268 | xfree(passphrase); |
| 269 | RSA_free(private_key); |
| 270 | xfree(comment); |
| 271 | exit(1); |
| 272 | } |
| 273 | |
| 274 | /* Destroy the passphrase and the private key in memory. */ |
| 275 | memset(passphrase, 0, strlen(passphrase)); |
| 276 | xfree(passphrase); |
| 277 | RSA_free(private_key); |
| 278 | |
| 279 | /* Save the public key in text format in a file with the same name but |
| 280 | .pub appended. */ |
| 281 | strcat(buf, ".pub"); |
| 282 | f = fopen(buf, "w"); |
| 283 | if (!f) |
| 284 | { |
| 285 | printf("Could not save your public key in %s\n", buf); |
| 286 | exit(1); |
| 287 | } |
| 288 | fprintf(f, "%d ", BN_num_bits(public_key->n)); |
| 289 | tmpbuf = BN_bn2dec(public_key->e); |
| 290 | fprintf(f, "%s ", tmpbuf); |
| 291 | free (tmpbuf); |
| 292 | tmpbuf = BN_bn2dec(public_key->n); |
| 293 | fprintf(f, "%s %s\n", tmpbuf, new_comment); |
| 294 | free (tmpbuf); |
| 295 | fclose(f); |
| 296 | |
| 297 | xfree(comment); |
| 298 | |
| 299 | printf("The comment in your key file has been changed.\n"); |
| 300 | exit(0); |
| 301 | } |
| 302 | |
| 303 | /* Main program for key management. */ |
| 304 | |
| 305 | int |
| 306 | main(int ac, char **av) |
| 307 | { |
| 308 | char buf[16384], buf2[1024], *passphrase1, *passphrase2; |
| 309 | struct passwd *pw; |
| 310 | char *tmpbuf; |
| 311 | int opt; |
| 312 | struct stat st; |
| 313 | FILE *f; |
| 314 | char hostname[MAXHOSTNAMELEN]; |
| 315 | extern int optind; |
| 316 | extern char *optarg; |
| 317 | |
| 318 | /* check if RSA support exists */ |
| 319 | if (rsa_alive() == 0) { |
| 320 | extern char *__progname; |
| 321 | |
| 322 | fprintf(stderr, |
| 323 | "%s: no RSA support in libssl and libcrypto. See ssl(8).\n", |
| 324 | __progname); |
| 325 | exit(1); |
| 326 | } |
| 327 | |
| 328 | /* Get user\'s passwd structure. We need this for the home directory. */ |
| 329 | pw = getpwuid(getuid()); |
| 330 | if (!pw) |
| 331 | { |
| 332 | printf("You don't exist, go away!\n"); |
| 333 | exit(1); |
| 334 | } |
| 335 | |
| 336 | /* Create ~/.ssh directory if it doesn\'t already exist. */ |
| 337 | snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, SSH_USER_DIR); |
| 338 | if (stat(buf, &st) < 0) |
| 339 | if (mkdir(buf, 0755) < 0) |
| 340 | error("Could not create directory '%s'.", buf); |
| 341 | |
| 342 | /* Parse command line arguments. */ |
| 343 | while ((opt = getopt(ac, av, "qpcb:f:P:N:C:")) != EOF) |
| 344 | { |
| 345 | switch (opt) |
| 346 | { |
| 347 | case 'b': |
| 348 | bits = atoi(optarg); |
| 349 | if (bits < 512 || bits > 32768) |
| 350 | { |
| 351 | printf("Bits has bad value.\n"); |
| 352 | exit(1); |
| 353 | } |
| 354 | break; |
| 355 | |
| 356 | case 'p': |
| 357 | change_passphrase = 1; |
| 358 | break; |
| 359 | |
| 360 | case 'c': |
| 361 | change_comment = 1; |
| 362 | break; |
| 363 | |
| 364 | case 'f': |
| 365 | identity_file = optarg; |
| 366 | break; |
| 367 | |
| 368 | case 'P': |
| 369 | identity_passphrase = optarg; |
| 370 | break; |
| 371 | |
| 372 | case 'N': |
| 373 | identity_new_passphrase = optarg; |
| 374 | break; |
| 375 | |
| 376 | case 'C': |
| 377 | identity_comment = optarg; |
| 378 | break; |
| 379 | |
| 380 | case 'q': |
| 381 | quiet = 1; |
| 382 | break; |
| 383 | |
| 384 | case '?': |
| 385 | default: |
| 386 | printf("ssh-keygen version %s\n", SSH_VERSION); |
| 387 | printf("Usage: %s [-b bits] [-p] [-c] [-f file] [-P pass] [-N new-pass] [-C comment]\n", av[0]); |
| 388 | exit(1); |
| 389 | } |
| 390 | } |
| 391 | if (optind < ac) |
| 392 | { |
| 393 | printf("Too many arguments.\n"); |
| 394 | exit(1); |
| 395 | } |
| 396 | if (change_passphrase && change_comment) |
| 397 | { |
| 398 | printf("Can only have one of -p and -c.\n"); |
| 399 | exit(1); |
| 400 | } |
| 401 | |
| 402 | /* If the user requested to change the passphrase, do it now. This |
| 403 | function never returns. */ |
| 404 | if (change_passphrase) |
| 405 | do_change_passphrase(pw); |
| 406 | |
| 407 | /* If the user requested to change the comment, do it now. This function |
| 408 | never returns. */ |
| 409 | if (change_comment) |
| 410 | do_change_comment(pw); |
| 411 | |
| 412 | arc4random_stir(); |
| 413 | |
| 414 | if (quiet) |
| 415 | rsa_set_verbose(0); |
| 416 | |
| 417 | /* Generate the rsa key pair. */ |
| 418 | private_key = RSA_new(); |
| 419 | public_key = RSA_new(); |
| 420 | rsa_generate_key(private_key, public_key, bits); |
| 421 | |
| 422 | ask_file_again: |
| 423 | |
| 424 | /* Ask for a file to save the key in. */ |
| 425 | if (identity_file) |
| 426 | { |
| 427 | strncpy(buf, identity_file, sizeof(buf)); |
| 428 | buf[sizeof(buf) - 1] = '\0'; |
| 429 | } |
| 430 | else |
| 431 | { |
| 432 | printf("Enter file in which to save the key ($HOME/%s): ", |
| 433 | SSH_CLIENT_IDENTITY); |
| 434 | fflush(stdout); |
| 435 | if (fgets(buf, sizeof(buf), stdin) == NULL) |
| 436 | exit(1); |
| 437 | if (strchr(buf, '\n')) |
| 438 | *strchr(buf, '\n') = 0; |
| 439 | if (strcmp(buf, "") == 0) |
| 440 | snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, SSH_CLIENT_IDENTITY); |
| 441 | } |
| 442 | |
| 443 | /* If the file aready exists, ask the user to confirm. */ |
| 444 | if (stat(buf, &st) >= 0) |
| 445 | { |
| 446 | printf("%s already exists.\n", buf); |
| 447 | printf("Overwrite (y/n)? "); |
| 448 | fflush(stdout); |
| 449 | if (fgets(buf2, sizeof(buf2), stdin) == NULL) |
| 450 | exit(1); |
| 451 | if (buf2[0] != 'y' && buf2[0] != 'Y') |
| 452 | exit(1); |
| 453 | } |
| 454 | |
| 455 | /* Ask for a passphrase (twice). */ |
| 456 | if (identity_passphrase) |
| 457 | passphrase1 = xstrdup(identity_passphrase); |
| 458 | else |
| 459 | if (identity_new_passphrase) |
| 460 | passphrase1 = xstrdup(identity_new_passphrase); |
| 461 | else |
| 462 | { |
| 463 | passphrase_again: |
| 464 | passphrase1 = |
| 465 | read_passphrase("Enter passphrase (empty for no passphrase): ", 1); |
| 466 | passphrase2 = read_passphrase("Enter same passphrase again: ", 1); |
| 467 | if (strcmp(passphrase1, passphrase2) != 0) |
| 468 | { |
| 469 | /* The passphrases do not match. Clear them and retry. */ |
| 470 | memset(passphrase1, 0, strlen(passphrase1)); |
| 471 | memset(passphrase2, 0, strlen(passphrase2)); |
| 472 | xfree(passphrase1); |
| 473 | xfree(passphrase2); |
| 474 | printf("Passphrases do not match. Try again.\n"); |
| 475 | goto passphrase_again; |
| 476 | } |
| 477 | /* Clear the other copy of the passphrase. */ |
| 478 | memset(passphrase2, 0, strlen(passphrase2)); |
| 479 | xfree(passphrase2); |
| 480 | } |
| 481 | |
| 482 | /* Create default commend field for the passphrase. The user can later |
| 483 | edit this field. */ |
| 484 | if (identity_comment) |
| 485 | { |
| 486 | strlcpy(buf2, identity_comment, sizeof(buf2)); |
| 487 | } |
| 488 | else |
| 489 | { |
| 490 | if (gethostname(hostname, sizeof(hostname)) < 0) |
| 491 | { |
| 492 | perror("gethostname"); |
| 493 | exit(1); |
| 494 | } |
| 495 | snprintf(buf2, sizeof buf2, "%s@%s", pw->pw_name, hostname); |
| 496 | } |
| 497 | |
| 498 | /* Save the key with the given passphrase and comment. */ |
| 499 | if (!save_private_key(buf, passphrase1, private_key, buf2)) |
| 500 | { |
| 501 | printf("Saving the key failed: %s: %s.\n", |
| 502 | buf, strerror(errno)); |
| 503 | memset(passphrase1, 0, strlen(passphrase1)); |
| 504 | xfree(passphrase1); |
| 505 | goto ask_file_again; |
| 506 | } |
| 507 | /* Clear the passphrase. */ |
| 508 | memset(passphrase1, 0, strlen(passphrase1)); |
| 509 | xfree(passphrase1); |
| 510 | |
| 511 | /* Clear the private key and the random number generator. */ |
| 512 | RSA_free(private_key); |
| 513 | arc4random_stir(); |
| 514 | |
| 515 | if (!quiet) |
| 516 | printf("Your identification has been saved in %s.\n", buf); |
| 517 | |
| 518 | /* Display the public key on the screen. */ |
| 519 | if (!quiet) { |
| 520 | printf("Your public key is:\n"); |
| 521 | printf("%d ", BN_num_bits(public_key->n)); |
| 522 | tmpbuf = BN_bn2dec(public_key->e); |
| 523 | printf("%s ", tmpbuf); |
| 524 | free(tmpbuf); |
| 525 | tmpbuf = BN_bn2dec(public_key->n); |
| 526 | printf("%s %s\n", tmpbuf, buf2); |
| 527 | free(tmpbuf); |
| 528 | } |
| 529 | |
| 530 | /* Save the public key in text format in a file with the same name but |
| 531 | .pub appended. */ |
| 532 | strcat(buf, ".pub"); |
| 533 | f = fopen(buf, "w"); |
| 534 | if (!f) |
| 535 | { |
| 536 | printf("Could not save your public key in %s\n", buf); |
| 537 | exit(1); |
| 538 | } |
| 539 | fprintf(f, "%d ", BN_num_bits(public_key->n)); |
| 540 | tmpbuf = BN_bn2dec(public_key->e); |
| 541 | fprintf(f, "%s ", tmpbuf); |
| 542 | free(tmpbuf); |
| 543 | tmpbuf = BN_bn2dec(public_key->n); |
| 544 | fprintf(f, "%s %s\n", tmpbuf, buf2); |
| 545 | free(tmpbuf); |
| 546 | fclose(f); |
| 547 | |
| 548 | if (!quiet) |
| 549 | printf("Your public key has been saved in %s\n", buf); |
| 550 | |
| 551 | exit(0); |
| 552 | } |