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 1.59 2001/04/23 21:57:07 markus Exp $");
  16
  17 #include <openssl/evp.h>
  18 #include <openssl/pem.h>
  19
  20 #include "xmalloc.h"
  21 #include "key.h"
  22 #include "rsa.h"
  23 #include "authfile.h"
  24 #include "uuencode.h"
  25 #include "buffer.h"
  26 #include "bufaux.h"
  27 #include "pathnames.h"
  28 #include "log.h"
  29 #include "readpass.h"
  30
  31 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  32 int bits = 1024;
  33
  34 /*
  35  * Flag indicating that we just want to change the passphrase.  This can be
  36  * set on the command line.
  37  */
  38 int change_passphrase = 0;
  39
  40 /*
  41  * Flag indicating that we just want to change the comment.  This can be set
  42  * on the command line.
  43  */
  44 int change_comment = 0;
  45
  46 int quiet = 0;
  47
  48 /* Flag indicating that we just want to see the key fingerprint */
  49 int print_fingerprint = 0;
  50 int print_bubblebabble = 0;
  51
  52 /* The identity file name, given on the command line or entered by the user. */
  53 char identity_file[1024];
  54 int have_identity = 0;
  55
  56 /* This is set to the passphrase if given on the command line. */
  57 char *identity_passphrase = NULL;
  58
  59 /* This is set to the new passphrase if given on the command line. */
  60 char *identity_new_passphrase = NULL;
  61
  62 /* This is set to the new comment if given on the command line. */
  63 char *identity_comment = NULL;
  64
  65 /* Dump public key file in format used by real and the original SSH 2 */
  66 int convert_to_ssh2 = 0;
  67 int convert_from_ssh2 = 0;
  68 int print_public = 0;
  69
  70 /* default to RSA for SSH-1 */
  71 char *key_type_name = "rsa1";
  72
  73 /* argv0 */
  74 #ifdef HAVE___PROGNAME
  75 extern char *__progname;
  76 #else
  77 char *__progname;
  78 #endif
  79
  80 char hostname[MAXHOSTNAMELEN];
  81
  82 void
  83 ask_filename(struct passwd *pw, const char *prompt)
  84 {
  85         char buf[1024];
  86         char *name = NULL;
  87
  88         switch (key_type_from_name(key_type_name)) {
  89         case KEY_RSA1:
  90                 name = _PATH_SSH_CLIENT_IDENTITY;
  91                 break;
  92         case KEY_DSA:
  93                 name = _PATH_SSH_CLIENT_ID_DSA;
  94                 break;
  95         case KEY_RSA:
  96                 name = _PATH_SSH_CLIENT_ID_RSA;
  97                 break;
  98         default:
  99                 fprintf(stderr, "bad key type");
 100                 exit(1);
 101                 break;
 102         }
 103         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 104         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 105         fflush(stderr);
 106         if (fgets(buf, sizeof(buf), stdin) == NULL)
 107                 exit(1);
 108         if (strchr(buf, '\n'))
 109                 *strchr(buf, '\n') = 0;
 110         if (strcmp(buf, "") != 0)
 111                 strlcpy(identity_file, buf, sizeof(identity_file));
 112         have_identity = 1;
 113 }
 114
 115 Key *
 116 try_load_pem_key(char *filename)
 117 {
 118         char *pass;
 119         Key *prv;
 120
 121         prv = key_load_private(filename, "", NULL);
 122         if (prv == NULL) {
 123                 pass = read_passphrase("Enter passphrase: ", 1);
 124                 prv = key_load_private(filename, pass, NULL);
 125                 memset(pass, 0, strlen(pass));
 126                 xfree(pass);
 127         }
 128         return prv;
 129 }
 130
 131 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 132 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 133 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 134 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 135
 136 void
 137 do_convert_to_ssh2(struct passwd *pw)
 138 {
 139         Key *k;
 140         int len;
 141         u_char *blob;
 142         struct stat st;
 143
 144         if (!have_identity)
 145                 ask_filename(pw, "Enter file in which the key is");
 146         if (stat(identity_file, &st) < 0) {
 147                 perror(identity_file);
 148                 exit(1);
 149         }
 150         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 151                 if ((k = try_load_pem_key(identity_file)) == NULL) {
 152                         fprintf(stderr, "load failed\n");
 153                         exit(1);
 154                 }
 155         }
 156         key_to_blob(k, &blob, &len);
 157         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 158         fprintf(stdout,
 159             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 160             key_size(k), key_type(k),
 161             pw->pw_name, hostname);
 162         dump_base64(stdout, blob, len);
 163         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 164         key_free(k);
 165         xfree(blob);
 166         exit(0);
 167 }
 168
 169 void
 170 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 171 {
 172         int bits = buffer_get_int(b);
 173         int bytes = (bits + 7) / 8;
 174
 175         if (buffer_len(b) < bytes)
 176                 fatal("buffer_get_bignum_bits: input buffer too small: "
 177                     "need %d have %d", bytes, buffer_len(b));
 178         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 179         buffer_consume(b, bytes);
 180 }
 181
 182 Key *
 183 do_convert_private_ssh2_from_blob(char *blob, int blen)
 184 {
 185         Buffer b;
 186         Key *key = NULL;
 187         int ignore, magic, rlen, ktype;
 188         char *type, *cipher;
 189
 190         buffer_init(&b);
 191         buffer_append(&b, blob, blen);
 192
 193         magic  = buffer_get_int(&b);
 194         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 195                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 196                 buffer_free(&b);
 197                 return NULL;
 198         }
 199         ignore = buffer_get_int(&b);
 200         type   = buffer_get_string(&b, NULL);
 201         cipher = buffer_get_string(&b, NULL);
 202         ignore = buffer_get_int(&b);
 203         ignore = buffer_get_int(&b);
 204         ignore = buffer_get_int(&b);
 205
 206         if (strcmp(cipher, "none") != 0) {
 207                 error("unsupported cipher %s", cipher);
 208                 xfree(cipher);
 209                 buffer_free(&b);
 210                 xfree(type);
 211                 return NULL;
 212         }
 213         xfree(cipher);
 214
 215         if (strstr(type, "dsa")) {
 216                 ktype = KEY_DSA;
 217         } else if (strstr(type, "rsa")) {
 218                 ktype = KEY_RSA;
 219         } else {
 220                 xfree(type);
 221                 return NULL;
 222         }
 223         key = key_new_private(ktype);
 224         xfree(type);
 225
 226         switch (key->type) {
 227         case KEY_DSA:
 228                 buffer_get_bignum_bits(&b, key->dsa->p);
 229                 buffer_get_bignum_bits(&b, key->dsa->g);
 230                 buffer_get_bignum_bits(&b, key->dsa->q);
 231                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 232                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 233                 break;
 234         case KEY_RSA:
 235                 if (!BN_set_word(key->rsa->e, (u_long) buffer_get_char(&b))) {
 236                         buffer_free(&b);
 237                         key_free(key);
 238                         return NULL;
 239                 }
 240                 buffer_get_bignum_bits(&b, key->rsa->d);
 241                 buffer_get_bignum_bits(&b, key->rsa->n);
 242                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 243                 buffer_get_bignum_bits(&b, key->rsa->q);
 244                 buffer_get_bignum_bits(&b, key->rsa->p);
 245                 generate_additional_parameters(key->rsa);
 246                 break;
 247         }
 248         rlen = buffer_len(&b);
 249         if(rlen != 0)
 250                 error("do_convert_private_ssh2_from_blob: "
 251                     "remaining bytes in key blob %d", rlen);
 252         buffer_free(&b);
 253 #ifdef DEBUG_PK
 254         {
 255                 u_int slen;
 256                 u_char *sig, data[10] = "abcde12345";
 257
 258                 key_sign(key, &sig, &slen, data, sizeof data);
 259                 key_verify(key, sig, slen, data, sizeof data);
 260                 xfree(sig);
 261         }
 262 #endif
 263         return key;
 264 }
 265
 266 void
 267 do_convert_from_ssh2(struct passwd *pw)
 268 {
 269         Key *k;
 270         int blen;
 271         char line[1024], *p;
 272         char blob[8096];
 273         char encoded[8096];
 274         struct stat st;
 275         int escaped = 0, private = 0, ok;
 276         FILE *fp;
 277
 278         if (!have_identity)
 279                 ask_filename(pw, "Enter file in which the key is");
 280         if (stat(identity_file, &st) < 0) {
 281                 perror(identity_file);
 282                 exit(1);
 283         }
 284         fp = fopen(identity_file, "r");
 285         if (fp == NULL) {
 286                 perror(identity_file);
 287                 exit(1);
 288         }
 289         encoded[0] = '\0';
 290         while (fgets(line, sizeof(line), fp)) {
 291                 if (!(p = strchr(line, '\n'))) {
 292                         fprintf(stderr, "input line too long.\n");
 293                         exit(1);
 294                 }
 295                 if (p > line && p[-1] == '\\')
 296                         escaped++;
 297                 if (strncmp(line, "----", 4) == 0 ||
 298                     strstr(line, ": ") != NULL) {
 299                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 300                                 private = 1;
 301                         fprintf(stderr, "ignore: %s", line);
 302                         continue;
 303                 }
 304                 if (escaped) {
 305                         escaped--;
 306                         fprintf(stderr, "escaped: %s", line);
 307                         continue;
 308                 }
 309                 *p = '\0';
 310                 strlcat(encoded, line, sizeof(encoded));
 311         }
 312         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 313         if (blen < 0) {
 314                 fprintf(stderr, "uudecode failed.\n");
 315                 exit(1);
 316         }
 317         k = private ?
 318             do_convert_private_ssh2_from_blob(blob, blen) :
 319             key_from_blob(blob, blen);
 320         if (k == NULL) {
 321                 fprintf(stderr, "decode blob failed.\n");
 322                 exit(1);
 323         }
 324         ok = private ?
 325             (k->type == KEY_DSA ?
 326                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 327                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 328             key_write(k, stdout);
 329         if (!ok) {
 330                 fprintf(stderr, "key write failed");
 331                 exit(1);
 332         }
 333         key_free(k);
 334         fprintf(stdout, "\n");
 335         fclose(fp);
 336         exit(0);
 337 }
 338
 339 void
 340 do_print_public(struct passwd *pw)
 341 {
 342         Key *prv;
 343         struct stat st;
 344
 345         if (!have_identity)
 346                 ask_filename(pw, "Enter file in which the key is");
 347         if (stat(identity_file, &st) < 0) {
 348                 perror(identity_file);
 349                 exit(1);
 350         }
 351         prv = try_load_pem_key(identity_file);
 352         if (prv == NULL) {
 353                 fprintf(stderr, "load failed\n");
 354                 exit(1);
 355         }
 356         if (!key_write(prv, stdout))
 357                 fprintf(stderr, "key_write failed");
 358         key_free(prv);
 359         fprintf(stdout, "\n");
 360         exit(0);
 361 }
 362
 363 void
 364 do_fingerprint(struct passwd *pw)
 365 {
 366         FILE *f;
 367         Key *public;
 368         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 369         int i, skip = 0, num = 1, invalid = 1, rep, fptype;
 370         struct stat st;
 371
 372         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 373         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 374
 375         if (!have_identity)
 376                 ask_filename(pw, "Enter file in which the key is");
 377         if (stat(identity_file, &st) < 0) {
 378                 perror(identity_file);
 379                 exit(1);
 380         }
 381         public = key_load_public(identity_file, &comment);
 382         if (public != NULL) {
 383                 fp = key_fingerprint(public, fptype, rep);
 384                 printf("%d %s %s\n", key_size(public), fp, comment);
 385                 key_free(public);
 386                 xfree(comment);
 387                 xfree(fp);
 388                 exit(0);
 389         }
 390         if (comment)
 391                 xfree(comment);
 392
 393         f = fopen(identity_file, "r");
 394         if (f != NULL) {
 395                 while (fgets(line, sizeof(line), f)) {
 396                         i = strlen(line) - 1;
 397                         if (line[i] != '\n') {
 398                                 error("line %d too long: %.40s...", num, line);
 399                                 skip = 1;
 400                                 continue;
 401                         }
 402                         num++;
 403                         if (skip) {
 404                                 skip = 0;
 405                                 continue;
 406                         }
 407                         line[i] = '\0';
 408
 409                         /* Skip leading whitespace, empty and comment lines. */
 410                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 411                                 ;
 412                         if (!*cp || *cp == '\n' || *cp == '#')
 413                                 continue ;
 414                         i = strtol(cp, &ep, 10);
 415                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 416                                 int quoted = 0;
 417                                 comment = cp;
 418                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 419                                         if (*cp == '\\' && cp[1] == '"')
 420                                                 cp++;   /* Skip both */
 421                                         else if (*cp == '"')
 422                                                 quoted = !quoted;
 423                                 }
 424                                 if (!*cp)
 425                                         continue;
 426                                 *cp++ = '\0';
 427                         }
 428                         ep = cp;
 429                         public = key_new(KEY_RSA1);
 430                         if (key_read(public, &cp) != 1) {
 431                                 cp = ep;
 432                                 key_free(public);
 433                                 public = key_new(KEY_UNSPEC);
 434                                 if (key_read(public, &cp) != 1) {
 435                                         key_free(public);
 436                                         continue;
 437                                 }
 438                         }
 439                         comment = *cp ? cp : comment;
 440                         fp = key_fingerprint(public, fptype, rep);
 441                         printf("%d %s %s\n", key_size(public), fp,
 442                             comment ? comment : "no comment");
 443                         xfree(fp);
 444                         key_free(public);
 445                         invalid = 0;
 446                 }
 447                 fclose(f);
 448         }
 449         if (invalid) {
 450                 printf("%s is not a valid key file.\n", identity_file);
 451                 exit(1);
 452         }
 453         exit(0);
 454 }
 455
 456 /*
 457  * Perform changing a passphrase.  The argument is the passwd structure
 458  * for the current user.
 459  */
 460 void
 461 do_change_passphrase(struct passwd *pw)
 462 {
 463         char *comment;
 464         char *old_passphrase, *passphrase1, *passphrase2;
 465         struct stat st;
 466         Key *private;
 467
 468         if (!have_identity)
 469                 ask_filename(pw, "Enter file in which the key is");
 470         if (stat(identity_file, &st) < 0) {
 471                 perror(identity_file);
 472                 exit(1);
 473         }
 474         /* Try to load the file with empty passphrase. */
 475         private = key_load_private(identity_file, "", &comment);
 476         if (private == NULL) {
 477                 if (identity_passphrase)
 478                         old_passphrase = xstrdup(identity_passphrase);
 479                 else
 480                         old_passphrase = read_passphrase("Enter old passphrase: ", 1);
 481                 private = key_load_private(identity_file, old_passphrase , &comment);
 482                 memset(old_passphrase, 0, strlen(old_passphrase));
 483                 xfree(old_passphrase);
 484                 if (private == NULL) {
 485                         printf("Bad passphrase.\n");
 486                         exit(1);
 487                 }
 488         }
 489         printf("Key has comment '%s'\n", comment);
 490
 491         /* Ask the new passphrase (twice). */
 492         if (identity_new_passphrase) {
 493                 passphrase1 = xstrdup(identity_new_passphrase);
 494                 passphrase2 = NULL;
 495         } else {
 496                 passphrase1 =
 497                         read_passphrase("Enter new passphrase (empty for no passphrase): ", 1);
 498                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 499
 500                 /* Verify that they are the same. */
 501                 if (strcmp(passphrase1, passphrase2) != 0) {
 502                         memset(passphrase1, 0, strlen(passphrase1));
 503                         memset(passphrase2, 0, strlen(passphrase2));
 504                         xfree(passphrase1);
 505                         xfree(passphrase2);
 506                         printf("Pass phrases do not match.  Try again.\n");
 507                         exit(1);
 508                 }
 509                 /* Destroy the other copy. */
 510                 memset(passphrase2, 0, strlen(passphrase2));
 511                 xfree(passphrase2);
 512         }
 513
 514         /* Save the file using the new passphrase. */
 515         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 516                 printf("Saving the key failed: %s.\n", identity_file);
 517                 memset(passphrase1, 0, strlen(passphrase1));
 518                 xfree(passphrase1);
 519                 key_free(private);
 520                 xfree(comment);
 521                 exit(1);
 522         }
 523         /* Destroy the passphrase and the copy of the key in memory. */
 524         memset(passphrase1, 0, strlen(passphrase1));
 525         xfree(passphrase1);
 526         key_free(private);               /* Destroys contents */
 527         xfree(comment);
 528
 529         printf("Your identification has been saved with the new passphrase.\n");
 530         exit(0);
 531 }
 532
 533 /*
 534  * Change the comment of a private key file.
 535  */
 536 void
 537 do_change_comment(struct passwd *pw)
 538 {
 539         char new_comment[1024], *comment, *passphrase;
 540         Key *private;
 541         Key *public;
 542         struct stat st;
 543         FILE *f;
 544         int fd;
 545
 546         if (!have_identity)
 547                 ask_filename(pw, "Enter file in which the key is");
 548         if (stat(identity_file, &st) < 0) {
 549                 perror(identity_file);
 550                 exit(1);
 551         }
 552         private = key_load_private(identity_file, "", &comment);
 553         if (private == NULL) {
 554                 if (identity_passphrase)
 555                         passphrase = xstrdup(identity_passphrase);
 556                 else if (identity_new_passphrase)
 557                         passphrase = xstrdup(identity_new_passphrase);
 558                 else
 559                         passphrase = read_passphrase("Enter passphrase: ", 1);
 560                 /* Try to load using the passphrase. */
 561                 private = key_load_private(identity_file, passphrase, &comment);
 562                 if (private == NULL) {
 563                         memset(passphrase, 0, strlen(passphrase));
 564                         xfree(passphrase);
 565                         printf("Bad passphrase.\n");
 566                         exit(1);
 567                 }
 568         } else {
 569                 passphrase = xstrdup("");
 570         }
 571         if (private->type != KEY_RSA1) {
 572                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 573                 key_free(private);
 574                 exit(1);
 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 (!key_save_private(private, identity_file, passphrase, new_comment)) {
 594                 printf("Saving the key failed: %s.\n", identity_file);
 595                 memset(passphrase, 0, strlen(passphrase));
 596                 xfree(passphrase);
 597                 key_free(private);
 598                 xfree(comment);
 599                 exit(1);
 600         }
 601         memset(passphrase, 0, strlen(passphrase));
 602         xfree(passphrase);
 603         public = key_from_private(private);
 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 [-ceilpqyB] [-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         seed_rng();
 656
 657         SSLeay_add_all_algorithms();
 658
 659         /* we need this for the home * directory.  */
 660         pw = getpwuid(getuid());
 661         if (!pw) {
 662                 printf("You don't exist, go away!\n");
 663                 exit(1);
 664         }
 665         if (gethostname(hostname, sizeof(hostname)) < 0) {
 666                 perror("gethostname");
 667                 exit(1);
 668         }
 669
 670         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:P:N:C:")) != -1) {
 671                 switch (opt) {
 672                 case 'b':
 673                         bits = atoi(optarg);
 674                         if (bits < 512 || bits > 32768) {
 675                                 printf("Bits has bad value.\n");
 676                                 exit(1);
 677                         }
 678                         break;
 679
 680                 case 'l':
 681                         print_fingerprint = 1;
 682                         break;
 683
 684                 case 'B':
 685                         print_bubblebabble = 1;
 686                         break;
 687
 688                 case 'p':
 689                         change_passphrase = 1;
 690                         break;
 691
 692                 case 'c':
 693                         change_comment = 1;
 694                         break;
 695
 696                 case 'f':
 697                         strlcpy(identity_file, optarg, sizeof(identity_file));
 698                         have_identity = 1;
 699                         break;
 700
 701                 case 'P':
 702                         identity_passphrase = optarg;
 703                         break;
 704
 705                 case 'N':
 706                         identity_new_passphrase = optarg;
 707                         break;
 708
 709                 case 'C':
 710                         identity_comment = optarg;
 711                         break;
 712
 713                 case 'q':
 714                         quiet = 1;
 715                         break;
 716
 717                 case 'R':
 718                         /* unused */
 719                         exit(0);
 720                         break;
 721
 722                 case 'e':
 723                 case 'x':
 724                         /* export key */
 725                         convert_to_ssh2 = 1;
 726                         break;
 727
 728                 case 'i':
 729                 case 'X':
 730                         /* import key */
 731                         convert_from_ssh2 = 1;
 732                         break;
 733
 734                 case 'y':
 735                         print_public = 1;
 736                         break;
 737
 738                 case 'd':
 739                         key_type_name = "dsa";
 740                         break;
 741
 742                 case 't':
 743                         key_type_name = optarg;
 744                         break;
 745
 746                 case '?':
 747                 default:
 748                         usage();
 749                 }
 750         }
 751         if (optind < ac) {
 752                 printf("Too many arguments.\n");
 753                 usage();
 754         }
 755         if (change_passphrase && change_comment) {
 756                 printf("Can only have one of -p and -c.\n");
 757                 usage();
 758         }
 759         if (print_fingerprint || print_bubblebabble)
 760                 do_fingerprint(pw);
 761         if (change_passphrase)
 762                 do_change_passphrase(pw);
 763         if (change_comment)
 764                 do_change_comment(pw);
 765         if (convert_to_ssh2)
 766                 do_convert_to_ssh2(pw);
 767         if (convert_from_ssh2)
 768                 do_convert_from_ssh2(pw);
 769         if (print_public)
 770                 do_print_public(pw);
 771
 772         arc4random_stir();
 773
 774         type = key_type_from_name(key_type_name);
 775         if (type == KEY_UNSPEC) {
 776                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 777                 exit(1);
 778         }
 779         if (!quiet)
 780                 printf("Generating public/private %s key pair.\n", key_type_name);
 781         private = key_generate(type, bits);
 782         if (private == NULL) {
 783                 fprintf(stderr, "key_generate failed");
 784                 exit(1);
 785         }
 786         public  = key_from_private(private);
 787
 788         if (!have_identity)
 789                 ask_filename(pw, "Enter file in which to save the key");
 790
 791         /* Create ~/.ssh directory if it doesn\'t already exist. */
 792         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 793         if (strstr(identity_file, dotsshdir) != NULL &&
 794             stat(dotsshdir, &st) < 0) {
 795                 if (mkdir(dotsshdir, 0700) < 0)
 796                         error("Could not create directory '%s'.", dotsshdir);
 797                 else if (!quiet)
 798                         printf("Created directory '%s'.\n", dotsshdir);
 799         }
 800         /* If the file already exists, ask the user to confirm. */
 801         if (stat(identity_file, &st) >= 0) {
 802                 char yesno[3];
 803                 printf("%s already exists.\n", identity_file);
 804                 printf("Overwrite (y/n)? ");
 805                 fflush(stdout);
 806                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 807                         exit(1);
 808                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 809                         exit(1);
 810         }
 811         /* Ask for a passphrase (twice). */
 812         if (identity_passphrase)
 813                 passphrase1 = xstrdup(identity_passphrase);
 814         else if (identity_new_passphrase)
 815                 passphrase1 = xstrdup(identity_new_passphrase);
 816         else {
 817 passphrase_again:
 818                 passphrase1 =
 819                         read_passphrase("Enter passphrase (empty for no passphrase): ", 1);
 820                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 821                 if (strcmp(passphrase1, passphrase2) != 0) {
 822                         /* The passphrases do not match.  Clear them and retry. */
 823                         memset(passphrase1, 0, strlen(passphrase1));
 824                         memset(passphrase2, 0, strlen(passphrase2));
 825                         xfree(passphrase1);
 826                         xfree(passphrase2);
 827                         printf("Passphrases do not match.  Try again.\n");
 828                         goto passphrase_again;
 829                 }
 830                 /* Clear the other copy of the passphrase. */
 831                 memset(passphrase2, 0, strlen(passphrase2));
 832                 xfree(passphrase2);
 833         }
 834
 835         if (identity_comment) {
 836                 strlcpy(comment, identity_comment, sizeof(comment));
 837         } else {
 838                 /* Create default commend field for the passphrase. */
 839                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 840         }
 841
 842         /* Save the key with the given passphrase and comment. */
 843         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 844                 printf("Saving the key failed: %s.\n", identity_file);
 845                 memset(passphrase1, 0, strlen(passphrase1));
 846                 xfree(passphrase1);
 847                 exit(1);
 848         }
 849         /* Clear the passphrase. */
 850         memset(passphrase1, 0, strlen(passphrase1));
 851         xfree(passphrase1);
 852
 853         /* Clear the private key and the random number generator. */
 854         key_free(private);
 855         arc4random_stir();
 856
 857         if (!quiet)
 858                 printf("Your identification has been saved in %s.\n", identity_file);
 859
 860         strlcat(identity_file, ".pub", sizeof(identity_file));
 861         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 862         if (fd == -1) {
 863                 printf("Could not save your public key in %s\n", identity_file);
 864                 exit(1);
 865         }
 866         f = fdopen(fd, "w");
 867         if (f == NULL) {
 868                 printf("fdopen %s failed", identity_file);
 869                 exit(1);
 870         }
 871         if (!key_write(public, f))
 872                 fprintf(stderr, "write key failed");
 873         fprintf(f, " %s\n", comment);
 874         fclose(f);
 875
 876         if (!quiet) {
 877                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 878                 printf("Your public key has been saved in %s.\n",
 879                     identity_file);
 880                 printf("The key fingerprint is:\n");
 881                 printf("%s %s\n", fp, comment);
 882                 xfree(fp);
 883         }
 884
 885         key_free(public);
 886         exit(0);
 887 }