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 1.43 2001/02/12 16:16:23 markus 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
  68 /* default to RSA for SSH-1 */
  69 char *key_type_name = "rsa1";
  70
  71 /* argv0 */
  72 #ifdef HAVE___PROGNAME
  73 extern char *__progname;
  74 #else
  75 char *__progname;
  76 #endif
  77
  78 char hostname[MAXHOSTNAMELEN];
  79
  80 void
  81 ask_filename(struct passwd *pw, const char *prompt)
  82 {
  83         char buf[1024];
  84         char *name = NULL;
  85
  86         switch (key_type_from_name(key_type_name)) {
  87         case KEY_RSA1:
  88                 name = _PATH_SSH_CLIENT_IDENTITY;
  89                 break;
  90         case KEY_DSA:
  91                 name = _PATH_SSH_CLIENT_ID_DSA;
  92                 break;
  93         case KEY_RSA:
  94                 name = _PATH_SSH_CLIENT_ID_RSA;
  95                 break;
  96         default:
  97                 fprintf(stderr, "bad key type");
  98                 exit(1);
  99                 break;
 100         }
 101         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 102         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 103         fflush(stderr);
 104         if (fgets(buf, sizeof(buf), stdin) == NULL)
 105                 exit(1);
 106         if (strchr(buf, '\n'))
 107                 *strchr(buf, '\n') = 0;
 108         if (strcmp(buf, "") != 0)
 109                 strlcpy(identity_file, buf, sizeof(identity_file));
 110         have_identity = 1;
 111 }
 112
 113 int
 114 try_load_key(char *filename, Key *k)
 115 {
 116         int success = 1;
 117         if (!load_private_key(filename, "", k, NULL)) {
 118                 char *pass = read_passphrase("Enter passphrase: ", 1);
 119                 if (!load_private_key(filename, pass, k, NULL)) {
 120                         success = 0;
 121                 }
 122                 memset(pass, 0, strlen(pass));
 123                 xfree(pass);
 124         }
 125         return success;
 126 }
 127
 128 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 129 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 130 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 131 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 132
 133 void
 134 do_convert_to_ssh2(struct passwd *pw)
 135 {
 136         Key *k;
 137         int len;
 138         u_char *blob;
 139         struct stat st;
 140
 141         if (!have_identity)
 142                 ask_filename(pw, "Enter file in which the key is");
 143         if (stat(identity_file, &st) < 0) {
 144                 perror(identity_file);
 145                 exit(1);
 146         }
 147         k = key_new(KEY_UNSPEC);
 148         if (!try_load_key(identity_file, k)) {
 149                 fprintf(stderr, "load failed\n");
 150                 exit(1);
 151         }
 152         key_to_blob(k, &blob, &len);
 153         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 154         fprintf(stdout,
 155             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 156             key_size(k), key_type(k),
 157             pw->pw_name, hostname);
 158         dump_base64(stdout, blob, len);
 159         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 160         key_free(k);
 161         xfree(blob);
 162         exit(0);
 163 }
 164
 165 void
 166 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 167 {
 168         int bits = buffer_get_int(b);
 169         int bytes = (bits + 7) / 8;
 170         if (buffer_len(b) < bytes)
 171                 fatal("buffer_get_bignum_bits: input buffer too small");
 172         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 173         buffer_consume(b, bytes);
 174 }
 175
 176 Key *
 177 do_convert_private_ssh2_from_blob(char *blob, int blen)
 178 {
 179         Buffer b;
 180         DSA *dsa;
 181         Key *key = NULL;
 182         int ignore, magic, rlen;
 183         char *type, *cipher;
 184
 185         buffer_init(&b);
 186         buffer_append(&b, blob, blen);
 187
 188         magic  = buffer_get_int(&b);
 189         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 190                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 191                 buffer_free(&b);
 192                 return NULL;
 193         }
 194         ignore = buffer_get_int(&b);
 195         type   = buffer_get_string(&b, NULL);
 196         cipher = buffer_get_string(&b, NULL);
 197         ignore = buffer_get_int(&b);
 198         ignore = buffer_get_int(&b);
 199         ignore = buffer_get_int(&b);
 200         xfree(type);
 201
 202         if (strcmp(cipher, "none") != 0) {
 203                 error("unsupported cipher %s", cipher);
 204                 xfree(cipher);
 205                 buffer_free(&b);
 206                 return NULL;
 207         }
 208         xfree(cipher);
 209
 210         key = key_new(KEY_DSA);
 211         dsa = key->dsa;
 212         dsa->priv_key = BN_new();
 213         if (dsa->priv_key == NULL) {
 214                 error("alloc priv_key failed");
 215                 key_free(key);
 216                 return NULL;
 217         }
 218         buffer_get_bignum_bits(&b, dsa->p);
 219         buffer_get_bignum_bits(&b, dsa->g);
 220         buffer_get_bignum_bits(&b, dsa->q);
 221         buffer_get_bignum_bits(&b, dsa->pub_key);
 222         buffer_get_bignum_bits(&b, dsa->priv_key);
 223         rlen = buffer_len(&b);
 224         if(rlen != 0)
 225                 error("do_convert_private_ssh2_from_blob: remaining bytes in key blob %d", rlen);
 226         buffer_free(&b);
 227         return key;
 228 }
 229
 230 void
 231 do_convert_from_ssh2(struct passwd *pw)
 232 {
 233         Key *k;
 234         int blen;
 235         char line[1024], *p;
 236         char blob[8096];
 237         char encoded[8096];
 238         struct stat st;
 239         int escaped = 0, private = 0, ok;
 240         FILE *fp;
 241
 242         if (!have_identity)
 243                 ask_filename(pw, "Enter file in which the key is");
 244         if (stat(identity_file, &st) < 0) {
 245                 perror(identity_file);
 246                 exit(1);
 247         }
 248         fp = fopen(identity_file, "r");
 249         if (fp == NULL) {
 250                 perror(identity_file);
 251                 exit(1);
 252         }
 253         encoded[0] = '\0';
 254         while (fgets(line, sizeof(line), fp)) {
 255                 if (!(p = strchr(line, '\n'))) {
 256                         fprintf(stderr, "input line too long.\n");
 257                         exit(1);
 258                 }
 259                 if (p > line && p[-1] == '\\')
 260                         escaped++;
 261                 if (strncmp(line, "----", 4) == 0 ||
 262                     strstr(line, ": ") != NULL) {
 263                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 264                                 private = 1;
 265                         fprintf(stderr, "ignore: %s", line);
 266                         continue;
 267                 }
 268                 if (escaped) {
 269                         escaped--;
 270                         fprintf(stderr, "escaped: %s", line);
 271                         continue;
 272                 }
 273                 *p = '\0';
 274                 strlcat(encoded, line, sizeof(encoded));
 275         }
 276         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 277         if (blen < 0) {
 278                 fprintf(stderr, "uudecode failed.\n");
 279                 exit(1);
 280         }
 281         k = private ?
 282             do_convert_private_ssh2_from_blob(blob, blen) :
 283             key_from_blob(blob, blen);
 284         if (k == NULL) {
 285                 fprintf(stderr, "decode blob failed.\n");
 286                 exit(1);
 287         }
 288         ok = private ?
 289             PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 290             key_write(k, stdout);
 291         if (!ok) {
 292                 fprintf(stderr, "key write failed");
 293                 exit(1);
 294         }
 295         key_free(k);
 296         fprintf(stdout, "\n");
 297         fclose(fp);
 298         exit(0);
 299 }
 300
 301 void
 302 do_print_public(struct passwd *pw)
 303 {
 304         Key *k;
 305         struct stat st;
 306
 307         if (!have_identity)
 308                 ask_filename(pw, "Enter file in which the key is");
 309         if (stat(identity_file, &st) < 0) {
 310                 perror(identity_file);
 311                 exit(1);
 312         }
 313         k = key_new(KEY_UNSPEC);
 314         if (!try_load_key(identity_file, k)) {
 315                 fprintf(stderr, "load failed\n");
 316                 exit(1);
 317         }
 318         if (!key_write(k, stdout))
 319                 fprintf(stderr, "key_write failed");
 320         key_free(k);
 321         fprintf(stdout, "\n");
 322         exit(0);
 323 }
 324
 325 void
 326 do_fingerprint(struct passwd *pw)
 327 {
 328
 329         FILE *f;
 330         Key *public;
 331         char *comment = NULL, *cp, *ep, line[16*1024];
 332         int i, skip = 0, num = 1, invalid = 1, success = 0;
 333         struct stat st;
 334
 335         if (!have_identity)
 336                 ask_filename(pw, "Enter file in which the key is");
 337         if (stat(identity_file, &st) < 0) {
 338                 perror(identity_file);
 339                 exit(1);
 340         }
 341         public = key_new(KEY_RSA1);
 342         if (load_public_key(identity_file, public, &comment)) {
 343                 success = 1;
 344         } else {
 345                 key_free(public);
 346                 public = key_new(KEY_UNSPEC);
 347                 if (try_load_public_key(identity_file, public, &comment))
 348                         success = 1;
 349                 else
 350                         debug("try_load_public_key KEY_UNSPEC failed");
 351         }
 352         if (success) {
 353                 printf("%d %s %s\n", key_size(public), key_fingerprint(public), comment);
 354                 key_free(public);
 355                 xfree(comment);
 356                 exit(0);
 357         }
 358
 359         f = fopen(identity_file, "r");
 360         if (f != NULL) {
 361                 while (fgets(line, sizeof(line), f)) {
 362                         i = strlen(line) - 1;
 363                         if (line[i] != '\n') {
 364                                 error("line %d too long: %.40s...", num, line);
 365                                 skip = 1;
 366                                 continue;
 367                         }
 368                         num++;
 369                         if (skip) {
 370                                 skip = 0;
 371                                 continue;
 372                         }
 373                         line[i] = '\0';
 374
 375                         /* Skip leading whitespace, empty and comment lines. */
 376                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 377                                 ;
 378                         if (!*cp || *cp == '\n' || *cp == '#')
 379                                 continue ;
 380                         i = strtol(cp, &ep, 10);
 381                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 382                                 int quoted = 0;
 383                                 comment = cp;
 384                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 385                                         if (*cp == '\\' && cp[1] == '"')
 386                                                 cp++;   /* Skip both */
 387                                         else if (*cp == '"')
 388                                                 quoted = !quoted;
 389                                 }
 390                                 if (!*cp)
 391                                         continue;
 392                                 *cp++ = '\0';
 393                         }
 394                         ep = cp;
 395                         public = key_new(KEY_RSA1);
 396                         if (key_read(public, &cp) != 1) {
 397                                 cp = ep;
 398                                 key_free(public);
 399                                 public = key_new(KEY_UNSPEC);
 400                                 if (key_read(public, &cp) != 1) {
 401                                         key_free(public);
 402                                         continue;
 403                                 }
 404                         }
 405                         comment = *cp ? cp : comment;
 406                         printf("%d %s %s\n", key_size(public),
 407                             key_fingerprint(public),
 408                             comment ? comment : "no comment");
 409                         invalid = 0;
 410                 }
 411                 fclose(f);
 412         }
 413         key_free(public);
 414         if (invalid) {
 415                 printf("%s is not a valid key file.\n", identity_file);
 416                 exit(1);
 417         }
 418         exit(0);
 419 }
 420
 421 /*
 422  * Perform changing a passphrase.  The argument is the passwd structure
 423  * for the current user.
 424  */
 425 void
 426 do_change_passphrase(struct passwd *pw)
 427 {
 428         char *comment;
 429         char *old_passphrase, *passphrase1, *passphrase2;
 430         struct stat st;
 431         Key *private;
 432         Key *public;
 433         int type = KEY_RSA1;
 434
 435         if (!have_identity)
 436                 ask_filename(pw, "Enter file in which the key is");
 437         if (stat(identity_file, &st) < 0) {
 438                 perror(identity_file);
 439                 exit(1);
 440         }
 441         public = key_new(type);
 442         if (!load_public_key(identity_file, public, NULL)) {
 443                 type = KEY_UNSPEC;
 444         } else {
 445                 /* Clear the public key since we are just about to load the whole file. */
 446                 key_free(public);
 447         }
 448         /* Try to load the file with empty passphrase. */
 449         private = key_new(type);
 450         if (!load_private_key(identity_file, "", private, &comment)) {
 451                 if (identity_passphrase)
 452                         old_passphrase = xstrdup(identity_passphrase);
 453                 else
 454                         old_passphrase = read_passphrase("Enter old passphrase: ", 1);
 455                 if (!load_private_key(identity_file, old_passphrase, private, &comment)) {
 456                         memset(old_passphrase, 0, strlen(old_passphrase));
 457                         xfree(old_passphrase);
 458                         printf("Bad passphrase.\n");
 459                         exit(1);
 460                 }
 461                 memset(old_passphrase, 0, strlen(old_passphrase));
 462                 xfree(old_passphrase);
 463         }
 464         printf("Key has comment '%s'\n", comment);
 465
 466         /* Ask the new passphrase (twice). */
 467         if (identity_new_passphrase) {
 468                 passphrase1 = xstrdup(identity_new_passphrase);
 469                 passphrase2 = NULL;
 470         } else {
 471                 passphrase1 =
 472                         read_passphrase("Enter new passphrase (empty for no passphrase): ", 1);
 473                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 474
 475                 /* Verify that they are the same. */
 476                 if (strcmp(passphrase1, passphrase2) != 0) {
 477                         memset(passphrase1, 0, strlen(passphrase1));
 478                         memset(passphrase2, 0, strlen(passphrase2));
 479                         xfree(passphrase1);
 480                         xfree(passphrase2);
 481                         printf("Pass phrases do not match.  Try again.\n");
 482                         exit(1);
 483                 }
 484                 /* Destroy the other copy. */
 485                 memset(passphrase2, 0, strlen(passphrase2));
 486                 xfree(passphrase2);
 487         }
 488
 489         /* Save the file using the new passphrase. */
 490         if (!save_private_key(identity_file, passphrase1, private, comment)) {
 491                 printf("Saving the key failed: %s: %s.\n",
 492                        identity_file, strerror(errno));
 493                 memset(passphrase1, 0, strlen(passphrase1));
 494                 xfree(passphrase1);
 495                 key_free(private);
 496                 xfree(comment);
 497                 exit(1);
 498         }
 499         /* Destroy the passphrase and the copy of the key in memory. */
 500         memset(passphrase1, 0, strlen(passphrase1));
 501         xfree(passphrase1);
 502         key_free(private);               /* Destroys contents */
 503         xfree(comment);
 504
 505         printf("Your identification has been saved with the new passphrase.\n");
 506         exit(0);
 507 }
 508
 509 /*
 510  * Change the comment of a private key file.
 511  */
 512 void
 513 do_change_comment(struct passwd *pw)
 514 {
 515         char new_comment[1024], *comment;
 516         Key *private;
 517         Key *public;
 518         char *passphrase;
 519         struct stat st;
 520         FILE *f;
 521
 522         if (!have_identity)
 523                 ask_filename(pw, "Enter file in which the key is");
 524         if (stat(identity_file, &st) < 0) {
 525                 perror(identity_file);
 526                 exit(1);
 527         }
 528         /*
 529          * Try to load the public key from the file the verify that it is
 530          * readable and of the proper format.
 531          */
 532         public = key_new(KEY_RSA1);
 533         if (!load_public_key(identity_file, public, NULL)) {
 534                 printf("%s is not a valid key file.\n", identity_file);
 535                 printf("Comments are only supported in RSA1 keys\n");
 536                 exit(1);
 537         }
 538
 539         private = key_new(KEY_RSA1);
 540         if (load_private_key(identity_file, "", private, &comment))
 541                 passphrase = xstrdup("");
 542         else {
 543                 if (identity_passphrase)
 544                         passphrase = xstrdup(identity_passphrase);
 545                 else if (identity_new_passphrase)
 546                         passphrase = xstrdup(identity_new_passphrase);
 547                 else
 548                         passphrase = read_passphrase("Enter passphrase: ", 1);
 549                 /* Try to load using the passphrase. */
 550                 if (!load_private_key(identity_file, passphrase, private, &comment)) {
 551                         memset(passphrase, 0, strlen(passphrase));
 552                         xfree(passphrase);
 553                         printf("Bad passphrase.\n");
 554                         exit(1);
 555                 }
 556         }
 557         printf("Key now has comment '%s'\n", comment);
 558
 559         if (identity_comment) {
 560                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 561         } else {
 562                 printf("Enter new comment: ");
 563                 fflush(stdout);
 564                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 565                         memset(passphrase, 0, strlen(passphrase));
 566                         key_free(private);
 567                         exit(1);
 568                 }
 569                 if (strchr(new_comment, '\n'))
 570                         *strchr(new_comment, '\n') = 0;
 571         }
 572
 573         /* Save the file using the new passphrase. */
 574         if (!save_private_key(identity_file, passphrase, private, new_comment)) {
 575                 printf("Saving the key failed: %s: %s.\n",
 576                        identity_file, strerror(errno));
 577                 memset(passphrase, 0, strlen(passphrase));
 578                 xfree(passphrase);
 579                 key_free(private);
 580                 xfree(comment);
 581                 exit(1);
 582         }
 583         memset(passphrase, 0, strlen(passphrase));
 584         xfree(passphrase);
 585         key_free(private);
 586
 587         strlcat(identity_file, ".pub", sizeof(identity_file));
 588         f = fopen(identity_file, "w");
 589         if (!f) {
 590                 printf("Could not save your public key in %s\n", identity_file);
 591                 exit(1);
 592         }
 593         if (!key_write(public, f))
 594                 fprintf(stderr, "write key failed");
 595         key_free(public);
 596         fprintf(f, " %s\n", new_comment);
 597         fclose(f);
 598
 599         xfree(comment);
 600
 601         printf("The comment in your key file has been changed.\n");
 602         exit(0);
 603 }
 604
 605 void
 606 usage(void)
 607 {
 608         printf("Usage: %s [-lpqxXyc] [-t type] [-b bits] [-f file] [-C comment] [-N new-pass] [-P pass]\n", __progname);
 609         exit(1);
 610 }
 611
 612 /*
 613  * Main program for key management.
 614  */
 615 int
 616 main(int ac, char **av)
 617 {
 618         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 619         struct passwd *pw;
 620         int opt, type;
 621         struct stat st;
 622         FILE *f;
 623         Key *private;
 624         Key *public;
 625
 626         extern int optind;
 627         extern char *optarg;
 628
 629         __progname = get_progname(av[0]);
 630         init_rng();
 631
 632         SSLeay_add_all_algorithms();
 633
 634         /* we need this for the home * directory.  */
 635         pw = getpwuid(getuid());
 636         if (!pw) {
 637                 printf("You don't exist, go away!\n");
 638                 exit(1);
 639         }
 640         if (gethostname(hostname, sizeof(hostname)) < 0) {
 641                 perror("gethostname");
 642                 exit(1);
 643         }
 644
 645         while ((opt = getopt(ac, av, "dqpclRxXyb:f:t:P:N:C:")) != -1) {
 646                 switch (opt) {
 647                 case 'b':
 648                         bits = atoi(optarg);
 649                         if (bits < 512 || bits > 32768) {
 650                                 printf("Bits has bad value.\n");
 651                                 exit(1);
 652                         }
 653                         break;
 654
 655                 case 'l':
 656                         print_fingerprint = 1;
 657                         break;
 658
 659                 case 'p':
 660                         change_passphrase = 1;
 661                         break;
 662
 663                 case 'c':
 664                         change_comment = 1;
 665                         break;
 666
 667                 case 'f':
 668                         strlcpy(identity_file, optarg, sizeof(identity_file));
 669                         have_identity = 1;
 670                         break;
 671
 672                 case 'P':
 673                         identity_passphrase = optarg;
 674                         break;
 675
 676                 case 'N':
 677                         identity_new_passphrase = optarg;
 678                         break;
 679
 680                 case 'C':
 681                         identity_comment = optarg;
 682                         break;
 683
 684                 case 'q':
 685                         quiet = 1;
 686                         break;
 687
 688                 case 'R':
 689                         /* unused */
 690                         exit(0);
 691                         break;
 692
 693                 case 'x':
 694                         convert_to_ssh2 = 1;
 695                         break;
 696
 697                 case 'X':
 698                         convert_from_ssh2 = 1;
 699                         break;
 700
 701                 case 'y':
 702                         print_public = 1;
 703                         break;
 704
 705                 case 'd':
 706                         key_type_name = "dsa";
 707                         break;
 708
 709                 case 't':
 710                         key_type_name = optarg;
 711                         break;
 712
 713                 case '?':
 714                 default:
 715                         usage();
 716                 }
 717         }
 718         if (optind < ac) {
 719                 printf("Too many arguments.\n");
 720                 usage();
 721         }
 722         if (change_passphrase && change_comment) {
 723                 printf("Can only have one of -p and -c.\n");
 724                 usage();
 725         }
 726         if (print_fingerprint)
 727                 do_fingerprint(pw);
 728         if (change_passphrase)
 729                 do_change_passphrase(pw);
 730         if (change_comment)
 731                 do_change_comment(pw);
 732         if (convert_to_ssh2)
 733                 do_convert_to_ssh2(pw);
 734         if (convert_from_ssh2)
 735                 do_convert_from_ssh2(pw);
 736         if (print_public)
 737                 do_print_public(pw);
 738
 739         arc4random_stir();
 740
 741         type = key_type_from_name(key_type_name);
 742         if (type == KEY_UNSPEC) {
 743                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 744                 exit(1);
 745         }
 746         if (!quiet)
 747                 printf("Generating public/private %s key pair.\n", key_type_name);
 748         private = key_generate(type, bits);
 749         if (private == NULL) {
 750                 fprintf(stderr, "key_generate failed");
 751                 exit(1);
 752         }
 753         public  = key_from_private(private);
 754
 755         if (!have_identity)
 756                 ask_filename(pw, "Enter file in which to save the key");
 757
 758         /* Create ~/.ssh directory if it doesn\'t already exist. */
 759         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 760         if (strstr(identity_file, dotsshdir) != NULL &&
 761             stat(dotsshdir, &st) < 0) {
 762                 if (mkdir(dotsshdir, 0700) < 0)
 763                         error("Could not create directory '%s'.", dotsshdir);
 764                 else if (!quiet)
 765                         printf("Created directory '%s'.\n", dotsshdir);
 766         }
 767         /* If the file already exists, ask the user to confirm. */
 768         if (stat(identity_file, &st) >= 0) {
 769                 char yesno[3];
 770                 printf("%s already exists.\n", identity_file);
 771                 printf("Overwrite (y/n)? ");
 772                 fflush(stdout);
 773                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 774                         exit(1);
 775                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 776                         exit(1);
 777         }
 778         /* Ask for a passphrase (twice). */
 779         if (identity_passphrase)
 780                 passphrase1 = xstrdup(identity_passphrase);
 781         else if (identity_new_passphrase)
 782                 passphrase1 = xstrdup(identity_new_passphrase);
 783         else {
 784 passphrase_again:
 785                 passphrase1 =
 786                         read_passphrase("Enter passphrase (empty for no passphrase): ", 1);
 787                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 788                 if (strcmp(passphrase1, passphrase2) != 0) {
 789                         /* The passphrases do not match.  Clear them and retry. */
 790                         memset(passphrase1, 0, strlen(passphrase1));
 791                         memset(passphrase2, 0, strlen(passphrase2));
 792                         xfree(passphrase1);
 793                         xfree(passphrase2);
 794                         printf("Passphrases do not match.  Try again.\n");
 795                         goto passphrase_again;
 796                 }
 797                 /* Clear the other copy of the passphrase. */
 798                 memset(passphrase2, 0, strlen(passphrase2));
 799                 xfree(passphrase2);
 800         }
 801
 802         if (identity_comment) {
 803                 strlcpy(comment, identity_comment, sizeof(comment));
 804         } else {
 805                 /* Create default commend field for the passphrase. */
 806                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 807         }
 808
 809         /* Save the key with the given passphrase and comment. */
 810         if (!save_private_key(identity_file, passphrase1, private, comment)) {
 811                 printf("Saving the key failed: %s: %s.\n",
 812                     identity_file, strerror(errno));
 813                 memset(passphrase1, 0, strlen(passphrase1));
 814                 xfree(passphrase1);
 815                 exit(1);
 816         }
 817         /* Clear the passphrase. */
 818         memset(passphrase1, 0, strlen(passphrase1));
 819         xfree(passphrase1);
 820
 821         /* Clear the private key and the random number generator. */
 822         key_free(private);
 823         arc4random_stir();
 824
 825         if (!quiet)
 826                 printf("Your identification has been saved in %s.\n", identity_file);
 827
 828         strlcat(identity_file, ".pub", sizeof(identity_file));
 829         f = fopen(identity_file, "w");
 830         if (!f) {
 831                 printf("Could not save your public key in %s\n", identity_file);
 832                 exit(1);
 833         }
 834         if (!key_write(public, f))
 835                 fprintf(stderr, "write key failed");
 836         fprintf(f, " %s\n", comment);
 837         fclose(f);
 838
 839         if (!quiet) {
 840                 printf("Your public key has been saved in %s.\n",
 841                     identity_file);
 842                 printf("The key fingerprint is:\n");
 843                 printf("%s %s\n", key_fingerprint(public), comment);
 844         }
 845
 846         key_free(public);
 847         exit(0);
 848 }