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Commit | Line | Data |
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8efc0c15 | 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" | |
17 | RCSID("$Id$"); | |
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); | |
120 | ||
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 | } |