ssh-keygen.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Identity and host key generation and maintenance.
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  */
  13
  14 #include "includes.h"
  15 RCSID("$OpenBSD: ssh-keygen.c,v 1.47 2001/03/11 15:04:16 jakob Exp $");
  16
  17 #include <openssl/evp.h>
  18 #include <openssl/pem.h>
  19
  20 #include "xmalloc.h"
  21 #include "key.h"
  22 #include "authfile.h"
  23 #include "uuencode.h"
  24 #include "buffer.h"
  25 #include "bufaux.h"
  26 #include "pathnames.h"
  27 #include "log.h"
  28 #include "readpass.h"
  29
  30 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  31 int bits = 1024;
  32
  33 /*
  34  * Flag indicating that we just want to change the passphrase.  This can be
  35  * set on the command line.
  36  */
  37 int change_passphrase = 0;
  38
  39 /*
  40  * Flag indicating that we just want to change the comment.  This can be set
  41  * on the command line.
  42  */
  43 int change_comment = 0;
  44
  45 int quiet = 0;
  46
  47 /* Flag indicating that we just want to see the key fingerprint */
  48 int print_fingerprint = 0;
  49
  50 /* The identity file name, given on the command line or entered by the user. */
  51 char identity_file[1024];
  52 int have_identity = 0;
  53
  54 /* This is set to the passphrase if given on the command line. */
  55 char *identity_passphrase = NULL;
  56
  57 /* This is set to the new passphrase if given on the command line. */
  58 char *identity_new_passphrase = NULL;
  59
  60 /* This is set to the new comment if given on the command line. */
  61 char *identity_comment = NULL;
  62
  63 /* Dump public key file in format used by real and the original SSH 2 */
  64 int convert_to_ssh2 = 0;
  65 int convert_from_ssh2 = 0;
  66 int print_public = 0;
  67 int print_verbose = 0;
  68
  69 /* default to RSA for SSH-1 */
  70 char *key_type_name = "rsa1";
  71
  72 /* argv0 */
  73 #ifdef HAVE___PROGNAME
  74 extern char *__progname;
  75 #else
  76 char *__progname;
  77 #endif
  78
  79 char hostname[MAXHOSTNAMELEN];
  80
  81 void
  82 ask_filename(struct passwd *pw, const char *prompt)
  83 {
  84         char buf[1024];
  85         char *name = NULL;
  86
  87         switch (key_type_from_name(key_type_name)) {
  88         case KEY_RSA1:
  89                 name = _PATH_SSH_CLIENT_IDENTITY;
  90                 break;
  91         case KEY_DSA:
  92                 name = _PATH_SSH_CLIENT_ID_DSA;
  93                 break;
  94         case KEY_RSA:
  95                 name = _PATH_SSH_CLIENT_ID_RSA;
  96                 break;
  97         default:
  98                 fprintf(stderr, "bad key type");
  99                 exit(1);
 100                 break;
 101         }
 102         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 103         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 104         fflush(stderr);
 105         if (fgets(buf, sizeof(buf), stdin) == NULL)
 106                 exit(1);
 107         if (strchr(buf, '\n'))
 108                 *strchr(buf, '\n') = 0;
 109         if (strcmp(buf, "") != 0)
 110                 strlcpy(identity_file, buf, sizeof(identity_file));
 111         have_identity = 1;
 112 }
 113
 114 int
 115 try_load_key(char *filename, Key *k)
 116 {
 117         int success = 1;
 118         if (!load_private_key(filename, "", k, NULL)) {
 119                 char *pass = read_passphrase("Enter passphrase: ", 1);
 120                 if (!load_private_key(filename, pass, k, NULL)) {
 121                         success = 0;
 122                 }
 123                 memset(pass, 0, strlen(pass));
 124                 xfree(pass);
 125         }
 126         return success;
 127 }
 128
 129 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 130 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 131 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 132 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 133
 134 void
 135 do_convert_to_ssh2(struct passwd *pw)
 136 {
 137         Key *k;
 138         int len;
 139         u_char *blob;
 140         struct stat st;
 141
 142         if (!have_identity)
 143                 ask_filename(pw, "Enter file in which the key is");
 144         if (stat(identity_file, &st) < 0) {
 145                 perror(identity_file);
 146                 exit(1);
 147         }
 148         k = key_new(KEY_UNSPEC);
 149         if (!try_load_key(identity_file, k)) {
 150                 fprintf(stderr, "load failed\n");
 151                 exit(1);
 152         }
 153         key_to_blob(k, &blob, &len);
 154         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 155         fprintf(stdout,
 156             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 157             key_size(k), key_type(k),
 158             pw->pw_name, hostname);
 159         dump_base64(stdout, blob, len);
 160         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 161         key_free(k);
 162         xfree(blob);
 163         exit(0);
 164 }
 165
 166 void
 167 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 168 {
 169         int bits = buffer_get_int(b);
 170         int bytes = (bits + 7) / 8;
 171         if (buffer_len(b) < bytes)
 172                 fatal("buffer_get_bignum_bits: input buffer too small");
 173         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 174         buffer_consume(b, bytes);
 175 }
 176
 177 Key *
 178 do_convert_private_ssh2_from_blob(char *blob, int blen)
 179 {
 180         Buffer b;
 181         DSA *dsa;
 182         Key *key = NULL;
 183         int ignore, magic, rlen;
 184         char *type, *cipher;
 185
 186         buffer_init(&b);
 187         buffer_append(&b, blob, blen);
 188
 189         magic  = buffer_get_int(&b);
 190         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 191                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 192                 buffer_free(&b);
 193                 return NULL;
 194         }
 195         ignore = buffer_get_int(&b);
 196         type   = buffer_get_string(&b, NULL);
 197         cipher = buffer_get_string(&b, NULL);
 198         ignore = buffer_get_int(&b);
 199         ignore = buffer_get_int(&b);
 200         ignore = buffer_get_int(&b);
 201         xfree(type);
 202
 203         if (strcmp(cipher, "none") != 0) {
 204                 error("unsupported cipher %s", cipher);
 205                 xfree(cipher);
 206                 buffer_free(&b);
 207                 return NULL;
 208         }
 209         xfree(cipher);
 210
 211         key = key_new(KEY_DSA);
 212         dsa = key->dsa;
 213         dsa->priv_key = BN_new();
 214         if (dsa->priv_key == NULL) {
 215                 error("alloc priv_key failed");
 216                 key_free(key);
 217                 return NULL;
 218         }
 219         buffer_get_bignum_bits(&b, dsa->p);
 220         buffer_get_bignum_bits(&b, dsa->g);
 221         buffer_get_bignum_bits(&b, dsa->q);
 222         buffer_get_bignum_bits(&b, dsa->pub_key);
 223         buffer_get_bignum_bits(&b, dsa->priv_key);
 224         rlen = buffer_len(&b);
 225         if(rlen != 0)
 226                 error("do_convert_private_ssh2_from_blob: remaining bytes in key blob %d", rlen);
 227         buffer_free(&b);
 228         return key;
 229 }
 230
 231 void
 232 do_convert_from_ssh2(struct passwd *pw)
 233 {
 234         Key *k;
 235         int blen;
 236         char line[1024], *p;
 237         char blob[8096];
 238         char encoded[8096];
 239         struct stat st;
 240         int escaped = 0, private = 0, ok;
 241         FILE *fp;
 242
 243         if (!have_identity)
 244                 ask_filename(pw, "Enter file in which the key is");
 245         if (stat(identity_file, &st) < 0) {
 246                 perror(identity_file);
 247                 exit(1);
 248         }
 249         fp = fopen(identity_file, "r");
 250         if (fp == NULL) {
 251                 perror(identity_file);
 252                 exit(1);
 253         }
 254         encoded[0] = '\0';
 255         while (fgets(line, sizeof(line), fp)) {
 256                 if (!(p = strchr(line, '\n'))) {
 257                         fprintf(stderr, "input line too long.\n");
 258                         exit(1);
 259                 }
 260                 if (p > line && p[-1] == '\\')
 261                         escaped++;
 262                 if (strncmp(line, "----", 4) == 0 ||
 263                     strstr(line, ": ") != NULL) {
 264                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 265                                 private = 1;
 266                         fprintf(stderr, "ignore: %s", line);
 267                         continue;
 268                 }
 269                 if (escaped) {
 270                         escaped--;
 271                         fprintf(stderr, "escaped: %s", line);
 272                         continue;
 273                 }
 274                 *p = '\0';
 275                 strlcat(encoded, line, sizeof(encoded));
 276         }
 277         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 278         if (blen < 0) {
 279                 fprintf(stderr, "uudecode failed.\n");
 280                 exit(1);
 281         }
 282         k = private ?
 283             do_convert_private_ssh2_from_blob(blob, blen) :
 284             key_from_blob(blob, blen);
 285         if (k == NULL) {
 286                 fprintf(stderr, "decode blob failed.\n");
 287                 exit(1);
 288         }
 289         ok = private ?
 290             PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 291             key_write(k, stdout);
 292         if (!ok) {
 293                 fprintf(stderr, "key write failed");
 294                 exit(1);
 295         }
 296         key_free(k);
 297         fprintf(stdout, "\n");
 298         fclose(fp);
 299         exit(0);
 300 }
 301
 302 void
 303 do_print_public(struct passwd *pw)
 304 {
 305         Key *k;
 306         struct stat st;
 307
 308         if (!have_identity)
 309                 ask_filename(pw, "Enter file in which the key is");
 310         if (stat(identity_file, &st) < 0) {
 311                 perror(identity_file);
 312                 exit(1);
 313         }
 314         k = key_new(KEY_UNSPEC);
 315         if (!try_load_key(identity_file, k)) {
 316                 fprintf(stderr, "load failed\n");
 317                 exit(1);
 318         }
 319         if (!key_write(k, stdout))
 320                 fprintf(stderr, "key_write failed");
 321         key_free(k);
 322         fprintf(stdout, "\n");
 323         exit(0);
 324 }
 325
 326 void
 327 do_fingerprint(struct passwd *pw)
 328 {
 329
 330         FILE *f;
 331         Key *public;
 332         char *comment = NULL, *cp, *ep, line[16*1024];
 333         int i, skip = 0, num = 1, invalid = 1, success = 0;
 334         struct stat st;
 335
 336         if (!have_identity)
 337                 ask_filename(pw, "Enter file in which the key is");
 338         if (stat(identity_file, &st) < 0) {
 339                 perror(identity_file);
 340                 exit(1);
 341         }
 342         public = key_new(KEY_RSA1);
 343         if (load_public_key(identity_file, public, &comment)) {
 344                 success = 1;
 345         } else {
 346                 key_free(public);
 347                 public = key_new(KEY_UNSPEC);
 348                 if (try_load_public_key(identity_file, public, &comment))
 349                         success = 1;
 350                 else
 351                         debug("try_load_public_key KEY_UNSPEC failed");
 352         }
 353         if (success) {
 354                 char *digest_md5, *digest_sha1, *digest_bubblebabble;
 355
 356                 digest_md5 = key_fingerprint_ex(public, SSH_FP_MD5, SSH_FP_HEX);
 357                 digest_sha1 = key_fingerprint_ex(public, SSH_FP_SHA1, SSH_FP_HEX);
 358                 digest_bubblebabble = key_fingerprint_ex(public, SSH_FP_SHA1, SSH_FP_BUBBLEBABBLE);
 359
 360                 if(print_verbose) {
 361                         printf("comment:      %s\n", comment);
 362                         printf("size:         %d\n", key_size(public));
 363                         printf("md5:          %s\n", digest_md5);
 364                         printf("sha1:         %s\n", digest_sha1);
 365                         printf("bubblebabble: %s\n", digest_bubblebabble);
 366                 } else {
 367                         printf("%d %s %s\n", key_size(public), digest_md5, comment);
 368                 }
 369
 370                 key_free(public);
 371                 xfree(comment);
 372                 xfree(digest_md5);
 373                 xfree(digest_sha1);
 374                 xfree(digest_bubblebabble);
 375
 376                 exit(0);
 377         }
 378
 379         f = fopen(identity_file, "r");
 380         if (f != NULL) {
 381                 while (fgets(line, sizeof(line), f)) {
 382                         i = strlen(line) - 1;
 383                         if (line[i] != '\n') {
 384                                 error("line %d too long: %.40s...", num, line);
 385                                 skip = 1;
 386                                 continue;
 387                         }
 388                         num++;
 389                         if (skip) {
 390                                 skip = 0;
 391                                 continue;
 392                         }
 393                         line[i] = '\0';
 394
 395                         /* Skip leading whitespace, empty and comment lines. */
 396                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 397                                 ;
 398                         if (!*cp || *cp == '\n' || *cp == '#')
 399                                 continue ;
 400                         i = strtol(cp, &ep, 10);
 401                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 402                                 int quoted = 0;
 403                                 comment = cp;
 404                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 405                                         if (*cp == '\\' && cp[1] == '"')
 406                                                 cp++;   /* Skip both */
 407                                         else if (*cp == '"')
 408                                                 quoted = !quoted;
 409                                 }
 410                                 if (!*cp)
 411                                         continue;
 412                                 *cp++ = '\0';
 413                         }
 414                         ep = cp;
 415                         public = key_new(KEY_RSA1);
 416                         if (key_read(public, &cp) != 1) {
 417                                 cp = ep;
 418                                 key_free(public);
 419                                 public = key_new(KEY_UNSPEC);
 420                                 if (key_read(public, &cp) != 1) {
 421                                         key_free(public);
 422                                         continue;
 423                                 }
 424                         }
 425                         comment = *cp ? cp : comment;
 426                         printf("%d %s %s\n", key_size(public),
 427                             key_fingerprint(public),
 428                             comment ? comment : "no comment");
 429                         invalid = 0;
 430                 }
 431                 fclose(f);
 432         }
 433         key_free(public);
 434         if (invalid) {
 435                 printf("%s is not a valid key file.\n", identity_file);
 436                 exit(1);
 437         }
 438         exit(0);
 439 }
 440
 441 /*
 442  * Perform changing a passphrase.  The argument is the passwd structure
 443  * for the current user.
 444  */
 445 void
 446 do_change_passphrase(struct passwd *pw)
 447 {
 448         char *comment;
 449         char *old_passphrase, *passphrase1, *passphrase2;
 450         struct stat st;
 451         Key *private;
 452         Key *public;
 453         int type = KEY_RSA1;
 454
 455         if (!have_identity)
 456                 ask_filename(pw, "Enter file in which the key is");
 457         if (stat(identity_file, &st) < 0) {
 458                 perror(identity_file);
 459                 exit(1);
 460         }
 461         public = key_new(type);
 462         if (!load_public_key(identity_file, public, NULL)) {
 463                 type = KEY_UNSPEC;
 464         } else {
 465                 /* Clear the public key since we are just about to load the whole file. */
 466                 key_free(public);
 467         }
 468         /* Try to load the file with empty passphrase. */
 469         private = key_new(type);
 470         if (!load_private_key(identity_file, "", private, &comment)) {
 471                 if (identity_passphrase)
 472                         old_passphrase = xstrdup(identity_passphrase);
 473                 else
 474                         old_passphrase = read_passphrase("Enter old passphrase: ", 1);
 475                 if (!load_private_key(identity_file, old_passphrase, private, &comment)) {
 476                         memset(old_passphrase, 0, strlen(old_passphrase));
 477                         xfree(old_passphrase);
 478                         printf("Bad passphrase.\n");
 479                         exit(1);
 480                 }
 481                 memset(old_passphrase, 0, strlen(old_passphrase));
 482                 xfree(old_passphrase);
 483         }
 484         printf("Key has comment '%s'\n", comment);
 485
 486         /* Ask the new passphrase (twice). */
 487         if (identity_new_passphrase) {
 488                 passphrase1 = xstrdup(identity_new_passphrase);
 489                 passphrase2 = NULL;
 490         } else {
 491                 passphrase1 =
 492                         read_passphrase("Enter new passphrase (empty for no passphrase): ", 1);
 493                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 494
 495                 /* Verify that they are the same. */
 496                 if (strcmp(passphrase1, passphrase2) != 0) {
 497                         memset(passphrase1, 0, strlen(passphrase1));
 498                         memset(passphrase2, 0, strlen(passphrase2));
 499                         xfree(passphrase1);
 500                         xfree(passphrase2);
 501                         printf("Pass phrases do not match.  Try again.\n");
 502                         exit(1);
 503                 }
 504                 /* Destroy the other copy. */
 505                 memset(passphrase2, 0, strlen(passphrase2));
 506                 xfree(passphrase2);
 507         }
 508
 509         /* Save the file using the new passphrase. */
 510         if (!save_private_key(identity_file, passphrase1, private, comment)) {
 511                 printf("Saving the key failed: %s: %s.\n",
 512                        identity_file, strerror(errno));
 513                 memset(passphrase1, 0, strlen(passphrase1));
 514                 xfree(passphrase1);
 515                 key_free(private);
 516                 xfree(comment);
 517                 exit(1);
 518         }
 519         /* Destroy the passphrase and the copy of the key in memory. */
 520         memset(passphrase1, 0, strlen(passphrase1));
 521         xfree(passphrase1);
 522         key_free(private);               /* Destroys contents */
 523         xfree(comment);
 524
 525         printf("Your identification has been saved with the new passphrase.\n");
 526         exit(0);
 527 }
 528
 529 /*
 530  * Change the comment of a private key file.
 531  */
 532 void
 533 do_change_comment(struct passwd *pw)
 534 {
 535         char new_comment[1024], *comment, *passphrase;
 536         Key *private, *public;
 537         struct stat st;
 538         FILE *f;
 539         int fd;
 540
 541         if (!have_identity)
 542                 ask_filename(pw, "Enter file in which the key is");
 543         if (stat(identity_file, &st) < 0) {
 544                 perror(identity_file);
 545                 exit(1);
 546         }
 547         /*
 548          * Try to load the public key from the file the verify that it is
 549          * readable and of the proper format.
 550          */
 551         public = key_new(KEY_RSA1);
 552         if (!load_public_key(identity_file, public, NULL)) {
 553                 printf("%s is not a valid key file.\n", identity_file);
 554                 printf("Comments are only supported in RSA1 keys\n");
 555                 exit(1);
 556         }
 557
 558         private = key_new(KEY_RSA1);
 559         if (load_private_key(identity_file, "", private, &comment))
 560                 passphrase = xstrdup("");
 561         else {
 562                 if (identity_passphrase)
 563                         passphrase = xstrdup(identity_passphrase);
 564                 else if (identity_new_passphrase)
 565                         passphrase = xstrdup(identity_new_passphrase);
 566                 else
 567                         passphrase = read_passphrase("Enter passphrase: ", 1);
 568                 /* Try to load using the passphrase. */
 569                 if (!load_private_key(identity_file, passphrase, private, &comment)) {
 570                         memset(passphrase, 0, strlen(passphrase));
 571                         xfree(passphrase);
 572                         printf("Bad passphrase.\n");
 573                         exit(1);
 574                 }
 575         }
 576         printf("Key now has comment '%s'\n", comment);
 577
 578         if (identity_comment) {
 579                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 580         } else {
 581                 printf("Enter new comment: ");
 582                 fflush(stdout);
 583                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 584                         memset(passphrase, 0, strlen(passphrase));
 585                         key_free(private);
 586                         exit(1);
 587                 }
 588                 if (strchr(new_comment, '\n'))
 589                         *strchr(new_comment, '\n') = 0;
 590         }
 591
 592         /* Save the file using the new passphrase. */
 593         if (!save_private_key(identity_file, passphrase, private, new_comment)) {
 594                 printf("Saving the key failed: %s: %s.\n",
 595                        identity_file, strerror(errno));
 596                 memset(passphrase, 0, strlen(passphrase));
 597                 xfree(passphrase);
 598                 key_free(private);
 599                 xfree(comment);
 600                 exit(1);
 601         }
 602         memset(passphrase, 0, strlen(passphrase));
 603         xfree(passphrase);
 604         key_free(private);
 605
 606         strlcat(identity_file, ".pub", sizeof(identity_file));
 607         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 608         if (fd == -1) {
 609                 printf("Could not save your public key in %s\n", identity_file);
 610                 exit(1);
 611         }
 612         f = fdopen(fd, "w");
 613         if (f == NULL) {
 614                 printf("fdopen %s failed", identity_file);
 615                 exit(1);
 616         }
 617         if (!key_write(public, f))
 618                 fprintf(stderr, "write key failed");
 619         key_free(public);
 620         fprintf(f, " %s\n", new_comment);
 621         fclose(f);
 622
 623         xfree(comment);
 624
 625         printf("The comment in your key file has been changed.\n");
 626         exit(0);
 627 }
 628
 629 void
 630 usage(void)
 631 {
 632         printf("Usage: %s [-lpqxXyc] [-t type] [-b bits] [-f file] [-C comment] "
 633             "[-N new-pass] [-P pass]\n", __progname);
 634         exit(1);
 635 }
 636
 637 /*
 638  * Main program for key management.
 639  */
 640 int
 641 main(int ac, char **av)
 642 {
 643         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 644         Key *private, *public;
 645         struct passwd *pw;
 646         int opt, type, fd;
 647         struct stat st;
 648         FILE *f;
 649
 650         extern int optind;
 651         extern char *optarg;
 652
 653         __progname = get_progname(av[0]);
 654         init_rng();
 655
 656         SSLeay_add_all_algorithms();
 657
 658         /* we need this for the home * directory.  */
 659         pw = getpwuid(getuid());
 660         if (!pw) {
 661                 printf("You don't exist, go away!\n");
 662                 exit(1);
 663         }
 664         if (gethostname(hostname, sizeof(hostname)) < 0) {
 665                 perror("gethostname");
 666                 exit(1);
 667         }
 668
 669         while ((opt = getopt(ac, av, "dqpclRxXyvb:f:t:P:N:C:")) != -1) {
 670                 switch (opt) {
 671                 case 'b':
 672                         bits = atoi(optarg);
 673                         if (bits < 512 || bits > 32768) {
 674                                 printf("Bits has bad value.\n");
 675                                 exit(1);
 676                         }
 677                         break;
 678
 679                 case 'l':
 680                         print_fingerprint = 1;
 681                         break;
 682
 683                 case 'p':
 684                         change_passphrase = 1;
 685                         break;
 686
 687                 case 'c':
 688                         change_comment = 1;
 689                         break;
 690
 691                 case 'f':
 692                         strlcpy(identity_file, optarg, sizeof(identity_file));
 693                         have_identity = 1;
 694                         break;
 695
 696                 case 'P':
 697                         identity_passphrase = optarg;
 698                         break;
 699
 700                 case 'N':
 701                         identity_new_passphrase = optarg;
 702                         break;
 703
 704                 case 'C':
 705                         identity_comment = optarg;
 706                         break;
 707
 708                 case 'q':
 709                         quiet = 1;
 710                         break;
 711
 712                 case 'R':
 713                         /* unused */
 714                         exit(0);
 715                         break;
 716
 717                 case 'x':
 718                         convert_to_ssh2 = 1;
 719                         break;
 720
 721                 case 'X':
 722                         convert_from_ssh2 = 1;
 723                         break;
 724
 725                 case 'y':
 726                         print_public = 1;
 727                         break;
 728
 729                 case 'v':
 730                         print_verbose = 1;
 731                         break;
 732
 733                 case 'd':
 734                         key_type_name = "dsa";
 735                         break;
 736
 737                 case 't':
 738                         key_type_name = optarg;
 739                         break;
 740
 741                 case '?':
 742                 default:
 743                         usage();
 744                 }
 745         }
 746         if (optind < ac) {
 747                 printf("Too many arguments.\n");
 748                 usage();
 749         }
 750         if (change_passphrase && change_comment) {
 751                 printf("Can only have one of -p and -c.\n");
 752                 usage();
 753         }
 754         if (print_fingerprint)
 755                 do_fingerprint(pw);
 756         if (change_passphrase)
 757                 do_change_passphrase(pw);
 758         if (change_comment)
 759                 do_change_comment(pw);
 760         if (convert_to_ssh2)
 761                 do_convert_to_ssh2(pw);
 762         if (convert_from_ssh2)
 763                 do_convert_from_ssh2(pw);
 764         if (print_public)
 765                 do_print_public(pw);
 766
 767         arc4random_stir();
 768
 769         type = key_type_from_name(key_type_name);
 770         if (type == KEY_UNSPEC) {
 771                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 772                 exit(1);
 773         }
 774         if (!quiet)
 775                 printf("Generating public/private %s key pair.\n", key_type_name);
 776         private = key_generate(type, bits);
 777         if (private == NULL) {
 778                 fprintf(stderr, "key_generate failed");
 779                 exit(1);
 780         }
 781         public  = key_from_private(private);
 782
 783         if (!have_identity)
 784                 ask_filename(pw, "Enter file in which to save the key");
 785
 786         /* Create ~/.ssh directory if it doesn\'t already exist. */
 787         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 788         if (strstr(identity_file, dotsshdir) != NULL &&
 789             stat(dotsshdir, &st) < 0) {
 790                 if (mkdir(dotsshdir, 0700) < 0)
 791                         error("Could not create directory '%s'.", dotsshdir);
 792                 else if (!quiet)
 793                         printf("Created directory '%s'.\n", dotsshdir);
 794         }
 795         /* If the file already exists, ask the user to confirm. */
 796         if (stat(identity_file, &st) >= 0) {
 797                 char yesno[3];
 798                 printf("%s already exists.\n", identity_file);
 799                 printf("Overwrite (y/n)? ");
 800                 fflush(stdout);
 801                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 802                         exit(1);
 803                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 804                         exit(1);
 805         }
 806         /* Ask for a passphrase (twice). */
 807         if (identity_passphrase)
 808                 passphrase1 = xstrdup(identity_passphrase);
 809         else if (identity_new_passphrase)
 810                 passphrase1 = xstrdup(identity_new_passphrase);
 811         else {
 812 passphrase_again:
 813                 passphrase1 =
 814                         read_passphrase("Enter passphrase (empty for no passphrase): ", 1);
 815                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 816                 if (strcmp(passphrase1, passphrase2) != 0) {
 817                         /* The passphrases do not match.  Clear them and retry. */
 818                         memset(passphrase1, 0, strlen(passphrase1));
 819                         memset(passphrase2, 0, strlen(passphrase2));
 820                         xfree(passphrase1);
 821                         xfree(passphrase2);
 822                         printf("Passphrases do not match.  Try again.\n");
 823                         goto passphrase_again;
 824                 }
 825                 /* Clear the other copy of the passphrase. */
 826                 memset(passphrase2, 0, strlen(passphrase2));
 827                 xfree(passphrase2);
 828         }
 829
 830         if (identity_comment) {
 831                 strlcpy(comment, identity_comment, sizeof(comment));
 832         } else {
 833                 /* Create default commend field for the passphrase. */
 834                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 835         }
 836
 837         /* Save the key with the given passphrase and comment. */
 838         if (!save_private_key(identity_file, passphrase1, private, comment)) {
 839                 printf("Saving the key failed: %s: %s.\n",
 840                     identity_file, strerror(errno));
 841                 memset(passphrase1, 0, strlen(passphrase1));
 842                 xfree(passphrase1);
 843                 exit(1);
 844         }
 845         /* Clear the passphrase. */
 846         memset(passphrase1, 0, strlen(passphrase1));
 847         xfree(passphrase1);
 848
 849         /* Clear the private key and the random number generator. */
 850         key_free(private);
 851         arc4random_stir();
 852
 853         if (!quiet)
 854                 printf("Your identification has been saved in %s.\n", identity_file);
 855
 856         strlcat(identity_file, ".pub", sizeof(identity_file));
 857         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 858         if (fd == -1) {
 859                 printf("Could not save your public key in %s\n", identity_file);
 860                 exit(1);
 861         }
 862         f = fdopen(fd, "w");
 863         if (f == NULL) {
 864                 printf("fdopen %s failed", identity_file);
 865                 exit(1);
 866         }
 867         if (!key_write(public, f))
 868                 fprintf(stderr, "write key failed");
 869         fprintf(f, " %s\n", comment);
 870         fclose(f);
 871
 872         if (!quiet) {
 873                 printf("Your public key has been saved in %s.\n",
 874                     identity_file);
 875                 printf("The key fingerprint is:\n");
 876                 printf("%s %s\n", key_fingerprint(public), comment);
 877         }
 878
 879         key_free(public);
 880         exit(0);
 881 }