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 1.56 2001/04/15 16:58:03 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 *prv;
 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         prv = try_load_pem_key(identity_file);
 151         if (prv == NULL) {
 152                 fprintf(stderr, "load failed\n");
 153                 exit(1);
 154         }
 155         key_to_blob(prv, &blob, &len);
 156         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 157         fprintf(stdout,
 158             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 159             key_size(prv), key_type(prv),
 160             pw->pw_name, hostname);
 161         dump_base64(stdout, blob, len);
 162         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 163         key_free(prv);
 164         xfree(blob);
 165         exit(0);
 166 }
 167
 168 void
 169 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 170 {
 171         int bits = buffer_get_int(b);
 172         int bytes = (bits + 7) / 8;
 173
 174         if (buffer_len(b) < bytes)
 175                 fatal("buffer_get_bignum_bits: input buffer too small: "
 176                     "need %d have %d", bytes, buffer_len(b));
 177         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 178         buffer_consume(b, bytes);
 179 }
 180
 181 Key *
 182 do_convert_private_ssh2_from_blob(char *blob, int blen)
 183 {
 184         Buffer b;
 185         Key *key = NULL;
 186         int ignore, magic, rlen, ktype;
 187         char *type, *cipher;
 188
 189         buffer_init(&b);
 190         buffer_append(&b, blob, blen);
 191
 192         magic  = buffer_get_int(&b);
 193         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 194                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 195                 buffer_free(&b);
 196                 return NULL;
 197         }
 198         ignore = buffer_get_int(&b);
 199         type   = buffer_get_string(&b, NULL);
 200         cipher = buffer_get_string(&b, NULL);
 201         ignore = buffer_get_int(&b);
 202         ignore = buffer_get_int(&b);
 203         ignore = buffer_get_int(&b);
 204
 205         if (strcmp(cipher, "none") != 0) {
 206                 error("unsupported cipher %s", cipher);
 207                 xfree(cipher);
 208                 buffer_free(&b);
 209                 xfree(type);
 210                 return NULL;
 211         }
 212         xfree(cipher);
 213
 214         if (strstr(type, "dsa")) {
 215                 ktype = KEY_DSA;
 216         } else if (strstr(type, "rsa")) {
 217                 ktype = KEY_RSA;
 218         } else {
 219                 xfree(type);
 220                 return NULL;
 221         }
 222         key = key_new_private(ktype);
 223         xfree(type);
 224
 225         switch (key->type) {
 226         case KEY_DSA:
 227                 buffer_get_bignum_bits(&b, key->dsa->p);
 228                 buffer_get_bignum_bits(&b, key->dsa->g);
 229                 buffer_get_bignum_bits(&b, key->dsa->q);
 230                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 231                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 232                 break;
 233         case KEY_RSA:
 234                 if (!BN_set_word(key->rsa->e, (u_long) buffer_get_char(&b))) {
 235                         buffer_free(&b);
 236                         key_free(key);
 237                         return NULL;
 238                 }
 239                 buffer_get_bignum_bits(&b, key->rsa->d);
 240                 buffer_get_bignum_bits(&b, key->rsa->n);
 241                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 242                 buffer_get_bignum_bits(&b, key->rsa->q);
 243                 buffer_get_bignum_bits(&b, key->rsa->p);
 244                 generate_additional_parameters(key->rsa);
 245                 break;
 246         }
 247         rlen = buffer_len(&b);
 248         if(rlen != 0)
 249                 error("do_convert_private_ssh2_from_blob: "
 250                     "remaining bytes in key blob %d", rlen);
 251         buffer_free(&b);
 252 #ifdef DEBUG_PK
 253         {
 254                 u_int slen;
 255                 u_char *sig, data[10] = "abcde12345";
 256
 257                 key_sign(key, &sig, &slen, data, sizeof data);
 258                 key_verify(key, sig, slen, data, sizeof data);
 259                 xfree(sig);
 260         }
 261 #endif
 262         return key;
 263 }
 264
 265 void
 266 do_convert_from_ssh2(struct passwd *pw)
 267 {
 268         Key *k;
 269         int blen;
 270         char line[1024], *p;
 271         char blob[8096];
 272         char encoded[8096];
 273         struct stat st;
 274         int escaped = 0, private = 0, ok;
 275         FILE *fp;
 276
 277         if (!have_identity)
 278                 ask_filename(pw, "Enter file in which the key is");
 279         if (stat(identity_file, &st) < 0) {
 280                 perror(identity_file);
 281                 exit(1);
 282         }
 283         fp = fopen(identity_file, "r");
 284         if (fp == NULL) {
 285                 perror(identity_file);
 286                 exit(1);
 287         }
 288         encoded[0] = '\0';
 289         while (fgets(line, sizeof(line), fp)) {
 290                 if (!(p = strchr(line, '\n'))) {
 291                         fprintf(stderr, "input line too long.\n");
 292                         exit(1);
 293                 }
 294                 if (p > line && p[-1] == '\\')
 295                         escaped++;
 296                 if (strncmp(line, "----", 4) == 0 ||
 297                     strstr(line, ": ") != NULL) {
 298                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 299                                 private = 1;
 300                         fprintf(stderr, "ignore: %s", line);
 301                         continue;
 302                 }
 303                 if (escaped) {
 304                         escaped--;
 305                         fprintf(stderr, "escaped: %s", line);
 306                         continue;
 307                 }
 308                 *p = '\0';
 309                 strlcat(encoded, line, sizeof(encoded));
 310         }
 311         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 312         if (blen < 0) {
 313                 fprintf(stderr, "uudecode failed.\n");
 314                 exit(1);
 315         }
 316         k = private ?
 317             do_convert_private_ssh2_from_blob(blob, blen) :
 318             key_from_blob(blob, blen);
 319         if (k == NULL) {
 320                 fprintf(stderr, "decode blob failed.\n");
 321                 exit(1);
 322         }
 323         ok = private ?
 324             (k->type == KEY_DSA ?
 325                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 326                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 327             key_write(k, stdout);
 328         if (!ok) {
 329                 fprintf(stderr, "key write failed");
 330                 exit(1);
 331         }
 332         key_free(k);
 333         fprintf(stdout, "\n");
 334         fclose(fp);
 335         exit(0);
 336 }
 337
 338 void
 339 do_print_public(struct passwd *pw)
 340 {
 341         Key *prv;
 342         struct stat st;
 343
 344         if (!have_identity)
 345                 ask_filename(pw, "Enter file in which the key is");
 346         if (stat(identity_file, &st) < 0) {
 347                 perror(identity_file);
 348                 exit(1);
 349         }
 350         prv = try_load_pem_key(identity_file);
 351         if (prv == NULL) {
 352                 fprintf(stderr, "load failed\n");
 353                 exit(1);
 354         }
 355         if (!key_write(prv, stdout))
 356                 fprintf(stderr, "key_write failed");
 357         key_free(prv);
 358         fprintf(stdout, "\n");
 359         exit(0);
 360 }
 361
 362 void
 363 do_fingerprint(struct passwd *pw)
 364 {
 365         FILE *f;
 366         Key *public;
 367         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 368         int i, skip = 0, num = 1, invalid = 1, rep, fptype;
 369         struct stat st;
 370
 371         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 372         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 373
 374         if (!have_identity)
 375                 ask_filename(pw, "Enter file in which the key is");
 376         if (stat(identity_file, &st) < 0) {
 377                 perror(identity_file);
 378                 exit(1);
 379         }
 380         public = key_load_public(identity_file, &comment);
 381         if (public != NULL) {
 382                 fp = key_fingerprint(public, fptype, rep);
 383                 printf("%d %s %s\n", key_size(public), fp, comment);
 384                 key_free(public);
 385                 xfree(comment);
 386                 xfree(fp);
 387                 exit(0);
 388         }
 389         if (comment)
 390                 xfree(comment);
 391
 392         f = fopen(identity_file, "r");
 393         if (f != NULL) {
 394                 while (fgets(line, sizeof(line), f)) {
 395                         i = strlen(line) - 1;
 396                         if (line[i] != '\n') {
 397                                 error("line %d too long: %.40s...", num, line);
 398                                 skip = 1;
 399                                 continue;
 400                         }
 401                         num++;
 402                         if (skip) {
 403                                 skip = 0;
 404                                 continue;
 405                         }
 406                         line[i] = '\0';
 407
 408                         /* Skip leading whitespace, empty and comment lines. */
 409                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 410                                 ;
 411                         if (!*cp || *cp == '\n' || *cp == '#')
 412                                 continue ;
 413                         i = strtol(cp, &ep, 10);
 414                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 415                                 int quoted = 0;
 416                                 comment = cp;
 417                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 418                                         if (*cp == '\\' && cp[1] == '"')
 419                                                 cp++;   /* Skip both */
 420                                         else if (*cp == '"')
 421                                                 quoted = !quoted;
 422                                 }
 423                                 if (!*cp)
 424                                         continue;
 425                                 *cp++ = '\0';
 426                         }
 427                         ep = cp;
 428                         public = key_new(KEY_RSA1);
 429                         if (key_read(public, &cp) != 1) {
 430                                 cp = ep;
 431                                 key_free(public);
 432                                 public = key_new(KEY_UNSPEC);
 433                                 if (key_read(public, &cp) != 1) {
 434                                         key_free(public);
 435                                         continue;
 436                                 }
 437                         }
 438                         comment = *cp ? cp : comment;
 439                         fp = key_fingerprint(public, fptype, rep);
 440                         printf("%d %s %s\n", key_size(public), fp,
 441                             comment ? comment : "no comment");
 442                         xfree(fp);
 443                         key_free(public);
 444                         invalid = 0;
 445                 }
 446                 fclose(f);
 447         }
 448         if (invalid) {
 449                 printf("%s is not a valid key file.\n", identity_file);
 450                 exit(1);
 451         }
 452         exit(0);
 453 }
 454
 455 /*
 456  * Perform changing a passphrase.  The argument is the passwd structure
 457  * for the current user.
 458  */
 459 void
 460 do_change_passphrase(struct passwd *pw)
 461 {
 462         char *comment;
 463         char *old_passphrase, *passphrase1, *passphrase2;
 464         struct stat st;
 465         Key *private;
 466
 467         if (!have_identity)
 468                 ask_filename(pw, "Enter file in which the key is");
 469         if (stat(identity_file, &st) < 0) {
 470                 perror(identity_file);
 471                 exit(1);
 472         }
 473         /* Try to load the file with empty passphrase. */
 474         private = key_load_private(identity_file, "", &comment);
 475         if (private == NULL) {
 476                 if (identity_passphrase)
 477                         old_passphrase = xstrdup(identity_passphrase);
 478                 else
 479                         old_passphrase = read_passphrase("Enter old passphrase: ", 1);
 480                 private = key_load_private(identity_file, old_passphrase , &comment);
 481                 memset(old_passphrase, 0, strlen(old_passphrase));
 482                 xfree(old_passphrase);
 483                 if (private == NULL) {
 484                         printf("Bad passphrase.\n");
 485                         exit(1);
 486                 }
 487         }
 488         printf("Key has comment '%s'\n", comment);
 489
 490         /* Ask the new passphrase (twice). */
 491         if (identity_new_passphrase) {
 492                 passphrase1 = xstrdup(identity_new_passphrase);
 493                 passphrase2 = NULL;
 494         } else {
 495                 passphrase1 =
 496                         read_passphrase("Enter new passphrase (empty for no passphrase): ", 1);
 497                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 498
 499                 /* Verify that they are the same. */
 500                 if (strcmp(passphrase1, passphrase2) != 0) {
 501                         memset(passphrase1, 0, strlen(passphrase1));
 502                         memset(passphrase2, 0, strlen(passphrase2));
 503                         xfree(passphrase1);
 504                         xfree(passphrase2);
 505                         printf("Pass phrases do not match.  Try again.\n");
 506                         exit(1);
 507                 }
 508                 /* Destroy the other copy. */
 509                 memset(passphrase2, 0, strlen(passphrase2));
 510                 xfree(passphrase2);
 511         }
 512
 513         /* Save the file using the new passphrase. */
 514         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 515                 printf("Saving the key failed: %s.\n", identity_file);
 516                 memset(passphrase1, 0, strlen(passphrase1));
 517                 xfree(passphrase1);
 518                 key_free(private);
 519                 xfree(comment);
 520                 exit(1);
 521         }
 522         /* Destroy the passphrase and the copy of the key in memory. */
 523         memset(passphrase1, 0, strlen(passphrase1));
 524         xfree(passphrase1);
 525         key_free(private);               /* Destroys contents */
 526         xfree(comment);
 527
 528         printf("Your identification has been saved with the new passphrase.\n");
 529         exit(0);
 530 }
 531
 532 /*
 533  * Change the comment of a private key file.
 534  */
 535 void
 536 do_change_comment(struct passwd *pw)
 537 {
 538         char new_comment[1024], *comment, *passphrase;
 539         Key *private;
 540         Key *public;
 541         struct stat st;
 542         FILE *f;
 543         int fd;
 544
 545         if (!have_identity)
 546                 ask_filename(pw, "Enter file in which the key is");
 547         if (stat(identity_file, &st) < 0) {
 548                 perror(identity_file);
 549                 exit(1);
 550         }
 551         private = key_load_private(identity_file, "", &comment);
 552         if (private == NULL) {
 553                 if (identity_passphrase)
 554                         passphrase = xstrdup(identity_passphrase);
 555                 else if (identity_new_passphrase)
 556                         passphrase = xstrdup(identity_new_passphrase);
 557                 else
 558                         passphrase = read_passphrase("Enter passphrase: ", 1);
 559                 /* Try to load using the passphrase. */
 560                 private = key_load_private(identity_file, passphrase, &comment);
 561                 if (private == NULL) {
 562                         memset(passphrase, 0, strlen(passphrase));
 563                         xfree(passphrase);
 564                         printf("Bad passphrase.\n");
 565                         exit(1);
 566                 }
 567         } else {
 568                 passphrase = xstrdup("");
 569         }
 570         if (private->type != KEY_RSA1) {
 571                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 572                 key_free(private);
 573                 exit(1);
 574         }
 575         printf("Key now has comment '%s'\n", comment);
 576
 577         if (identity_comment) {
 578                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 579         } else {
 580                 printf("Enter new comment: ");
 581                 fflush(stdout);
 582                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 583                         memset(passphrase, 0, strlen(passphrase));
 584                         key_free(private);
 585                         exit(1);
 586                 }
 587                 if (strchr(new_comment, '\n'))
 588                         *strchr(new_comment, '\n') = 0;
 589         }
 590
 591         /* Save the file using the new passphrase. */
 592         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 593                 printf("Saving the key failed: %s.\n", identity_file);
 594                 memset(passphrase, 0, strlen(passphrase));
 595                 xfree(passphrase);
 596                 key_free(private);
 597                 xfree(comment);
 598                 exit(1);
 599         }
 600         memset(passphrase, 0, strlen(passphrase));
 601         xfree(passphrase);
 602         public = key_from_private(private);
 603         key_free(private);
 604
 605         strlcat(identity_file, ".pub", sizeof(identity_file));
 606         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 607         if (fd == -1) {
 608                 printf("Could not save your public key in %s\n", identity_file);
 609                 exit(1);
 610         }
 611         f = fdopen(fd, "w");
 612         if (f == NULL) {
 613                 printf("fdopen %s failed", identity_file);
 614                 exit(1);
 615         }
 616         if (!key_write(public, f))
 617                 fprintf(stderr, "write key failed");
 618         key_free(public);
 619         fprintf(f, " %s\n", new_comment);
 620         fclose(f);
 621
 622         xfree(comment);
 623
 624         printf("The comment in your key file has been changed.\n");
 625         exit(0);
 626 }
 627
 628 void
 629 usage(void)
 630 {
 631         printf("Usage: %s [-lBpqxXyc] [-t type] [-b bits] [-f file] [-C comment] "
 632             "[-N new-pass] [-P pass]\n", __progname);
 633         exit(1);
 634 }
 635
 636 /*
 637  * Main program for key management.
 638  */
 639 int
 640 main(int ac, char **av)
 641 {
 642         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 643         Key *private, *public;
 644         struct passwd *pw;
 645         int opt, type, fd;
 646         struct stat st;
 647         FILE *f;
 648
 649         extern int optind;
 650         extern char *optarg;
 651
 652         __progname = get_progname(av[0]);
 653         init_rng();
 654         seed_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, "dqpclBRxXyb: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 'B':
 684                         print_bubblebabble = 1;
 685                         break;
 686
 687                 case 'p':
 688                         change_passphrase = 1;
 689                         break;
 690
 691                 case 'c':
 692                         change_comment = 1;
 693                         break;
 694
 695                 case 'f':
 696                         strlcpy(identity_file, optarg, sizeof(identity_file));
 697                         have_identity = 1;
 698                         break;
 699
 700                 case 'P':
 701                         identity_passphrase = optarg;
 702                         break;
 703
 704                 case 'N':
 705                         identity_new_passphrase = optarg;
 706                         break;
 707
 708                 case 'C':
 709                         identity_comment = optarg;
 710                         break;
 711
 712                 case 'q':
 713                         quiet = 1;
 714                         break;
 715
 716                 case 'R':
 717                         /* unused */
 718                         exit(0);
 719                         break;
 720
 721                 case 'x':
 722                         convert_to_ssh2 = 1;
 723                         break;
 724
 725                 case 'X':
 726                         convert_from_ssh2 = 1;
 727                         break;
 728
 729                 case 'y':
 730                         print_public = 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 || print_bubblebabble)
 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 (!key_save_private(private, identity_file, passphrase1, comment)) {
 839                 printf("Saving the key failed: %s.\n", identity_file);
 840                 memset(passphrase1, 0, strlen(passphrase1));
 841                 xfree(passphrase1);
 842                 exit(1);
 843         }
 844         /* Clear the passphrase. */
 845         memset(passphrase1, 0, strlen(passphrase1));
 846         xfree(passphrase1);
 847
 848         /* Clear the private key and the random number generator. */
 849         key_free(private);
 850         arc4random_stir();
 851
 852         if (!quiet)
 853                 printf("Your identification has been saved in %s.\n", identity_file);
 854
 855         strlcat(identity_file, ".pub", sizeof(identity_file));
 856         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 857         if (fd == -1) {
 858                 printf("Could not save your public key in %s\n", identity_file);
 859                 exit(1);
 860         }
 861         f = fdopen(fd, "w");
 862         if (f == NULL) {
 863                 printf("fdopen %s failed", identity_file);
 864                 exit(1);
 865         }
 866         if (!key_write(public, f))
 867                 fprintf(stderr, "write key failed");
 868         fprintf(f, " %s\n", comment);
 869         fclose(f);
 870
 871         if (!quiet) {
 872                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 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", fp, comment);
 877                 xfree(fp);
 878         }
 879
 880         key_free(public);
 881         exit(0);
 882 }