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 1.62 2001/06/23 06:41:10 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 load_identity(char *filename)
 117 {
 118         char *pass;
 119         Key *prv;
 120
 121         prv = key_load_private(filename, "", NULL);
 122         if (prv == NULL) {
 123                 if (identity_passphrase)
 124                         pass = xstrdup(identity_passphrase);
 125                 else
 126                         pass = read_passphrase("Enter passphrase: ", 1);
 127                 prv = key_load_private(filename, pass, NULL);
 128                 memset(pass, 0, strlen(pass));
 129                 xfree(pass);
 130         }
 131         return prv;
 132 }
 133
 134 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 135 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 136 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 137 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 138
 139 void
 140 do_convert_to_ssh2(struct passwd *pw)
 141 {
 142         Key *k;
 143         int len;
 144         u_char *blob;
 145         struct stat st;
 146
 147         if (!have_identity)
 148                 ask_filename(pw, "Enter file in which the key is");
 149         if (stat(identity_file, &st) < 0) {
 150                 perror(identity_file);
 151                 exit(1);
 152         }
 153         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 154                 if ((k = load_identity(identity_file)) == NULL) {
 155                         fprintf(stderr, "load failed\n");
 156                         exit(1);
 157                 }
 158         }
 159         key_to_blob(k, &blob, &len);
 160         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 161         fprintf(stdout,
 162             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 163             key_size(k), key_type(k),
 164             pw->pw_name, hostname);
 165         dump_base64(stdout, blob, len);
 166         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 167         key_free(k);
 168         xfree(blob);
 169         exit(0);
 170 }
 171
 172 void
 173 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 174 {
 175         int bits = buffer_get_int(b);
 176         int bytes = (bits + 7) / 8;
 177
 178         if (buffer_len(b) < bytes)
 179                 fatal("buffer_get_bignum_bits: input buffer too small: "
 180                     "need %d have %d", bytes, buffer_len(b));
 181         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 182         buffer_consume(b, bytes);
 183 }
 184
 185 Key *
 186 do_convert_private_ssh2_from_blob(char *blob, int blen)
 187 {
 188         Buffer b;
 189         Key *key = NULL;
 190         int magic, rlen, ktype, i1, i2, i3, i4;
 191         u_long e;
 192         char *type, *cipher;
 193
 194         buffer_init(&b);
 195         buffer_append(&b, blob, blen);
 196
 197         magic  = buffer_get_int(&b);
 198         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 199                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 200                 buffer_free(&b);
 201                 return NULL;
 202         }
 203         i1 = buffer_get_int(&b);
 204         type   = buffer_get_string(&b, NULL);
 205         cipher = buffer_get_string(&b, NULL);
 206         i2 = buffer_get_int(&b);
 207         i3 = buffer_get_int(&b);
 208         i4 = buffer_get_int(&b);
 209         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 210         if (strcmp(cipher, "none") != 0) {
 211                 error("unsupported cipher %s", cipher);
 212                 xfree(cipher);
 213                 buffer_free(&b);
 214                 xfree(type);
 215                 return NULL;
 216         }
 217         xfree(cipher);
 218
 219         if (strstr(type, "dsa")) {
 220                 ktype = KEY_DSA;
 221         } else if (strstr(type, "rsa")) {
 222                 ktype = KEY_RSA;
 223         } else {
 224                 xfree(type);
 225                 return NULL;
 226         }
 227         key = key_new_private(ktype);
 228         xfree(type);
 229
 230         switch (key->type) {
 231         case KEY_DSA:
 232                 buffer_get_bignum_bits(&b, key->dsa->p);
 233                 buffer_get_bignum_bits(&b, key->dsa->g);
 234                 buffer_get_bignum_bits(&b, key->dsa->q);
 235                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 236                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 237                 break;
 238         case KEY_RSA:
 239                 e  = buffer_get_char(&b);
 240                 debug("e %lx", e);
 241                 if (e < 30) {
 242                         e <<= 8;
 243                         e += buffer_get_char(&b);
 244                         debug("e %lx", e);
 245                         e <<= 8;
 246                         e += buffer_get_char(&b);
 247                         debug("e %lx", e);
 248                 }
 249                 if (!BN_set_word(key->rsa->e, e)) {
 250                         buffer_free(&b);
 251                         key_free(key);
 252                         return NULL;
 253                 }
 254                 buffer_get_bignum_bits(&b, key->rsa->d);
 255                 buffer_get_bignum_bits(&b, key->rsa->n);
 256                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 257                 buffer_get_bignum_bits(&b, key->rsa->q);
 258                 buffer_get_bignum_bits(&b, key->rsa->p);
 259                 generate_additional_parameters(key->rsa);
 260                 break;
 261         }
 262         rlen = buffer_len(&b);
 263         if(rlen != 0)
 264                 error("do_convert_private_ssh2_from_blob: "
 265                     "remaining bytes in key blob %d", rlen);
 266         buffer_free(&b);
 267 #ifdef DEBUG_PK
 268         {
 269                 u_int slen;
 270                 u_char *sig, data[10] = "abcde12345";
 271
 272                 key_sign(key, &sig, &slen, data, sizeof(data));
 273                 key_verify(key, sig, slen, data, sizeof(data));
 274                 xfree(sig);
 275         }
 276 #endif
 277         return key;
 278 }
 279
 280 void
 281 do_convert_from_ssh2(struct passwd *pw)
 282 {
 283         Key *k;
 284         int blen;
 285         char line[1024], *p;
 286         char blob[8096];
 287         char encoded[8096];
 288         struct stat st;
 289         int escaped = 0, private = 0, ok;
 290         FILE *fp;
 291
 292         if (!have_identity)
 293                 ask_filename(pw, "Enter file in which the key is");
 294         if (stat(identity_file, &st) < 0) {
 295                 perror(identity_file);
 296                 exit(1);
 297         }
 298         fp = fopen(identity_file, "r");
 299         if (fp == NULL) {
 300                 perror(identity_file);
 301                 exit(1);
 302         }
 303         encoded[0] = '\0';
 304         while (fgets(line, sizeof(line), fp)) {
 305                 if (!(p = strchr(line, '\n'))) {
 306                         fprintf(stderr, "input line too long.\n");
 307                         exit(1);
 308                 }
 309                 if (p > line && p[-1] == '\\')
 310                         escaped++;
 311                 if (strncmp(line, "----", 4) == 0 ||
 312                     strstr(line, ": ") != NULL) {
 313                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 314                                 private = 1;
 315                         /* fprintf(stderr, "ignore: %s", line); */
 316                         continue;
 317                 }
 318                 if (escaped) {
 319                         escaped--;
 320                         /* fprintf(stderr, "escaped: %s", line); */
 321                         continue;
 322                 }
 323                 *p = '\0';
 324                 strlcat(encoded, line, sizeof(encoded));
 325         }
 326         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 327         if (blen < 0) {
 328                 fprintf(stderr, "uudecode failed.\n");
 329                 exit(1);
 330         }
 331         k = private ?
 332             do_convert_private_ssh2_from_blob(blob, blen) :
 333             key_from_blob(blob, blen);
 334         if (k == NULL) {
 335                 fprintf(stderr, "decode blob failed.\n");
 336                 exit(1);
 337         }
 338         ok = private ?
 339             (k->type == KEY_DSA ?
 340                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 341                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 342             key_write(k, stdout);
 343         if (!ok) {
 344                 fprintf(stderr, "key write failed");
 345                 exit(1);
 346         }
 347         key_free(k);
 348         fprintf(stdout, "\n");
 349         fclose(fp);
 350         exit(0);
 351 }
 352
 353 void
 354 do_print_public(struct passwd *pw)
 355 {
 356         Key *prv;
 357         struct stat st;
 358
 359         if (!have_identity)
 360                 ask_filename(pw, "Enter file in which the key is");
 361         if (stat(identity_file, &st) < 0) {
 362                 perror(identity_file);
 363                 exit(1);
 364         }
 365         prv = load_identity(identity_file);
 366         if (prv == NULL) {
 367                 fprintf(stderr, "load failed\n");
 368                 exit(1);
 369         }
 370         if (!key_write(prv, stdout))
 371                 fprintf(stderr, "key_write failed");
 372         key_free(prv);
 373         fprintf(stdout, "\n");
 374         exit(0);
 375 }
 376
 377 void
 378 do_fingerprint(struct passwd *pw)
 379 {
 380         FILE *f;
 381         Key *public;
 382         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 383         int i, skip = 0, num = 1, invalid = 1, rep, fptype;
 384         struct stat st;
 385
 386         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 387         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 388
 389         if (!have_identity)
 390                 ask_filename(pw, "Enter file in which the key is");
 391         if (stat(identity_file, &st) < 0) {
 392                 perror(identity_file);
 393                 exit(1);
 394         }
 395         public = key_load_public(identity_file, &comment);
 396         if (public != NULL) {
 397                 fp = key_fingerprint(public, fptype, rep);
 398                 printf("%d %s %s\n", key_size(public), fp, comment);
 399                 key_free(public);
 400                 xfree(comment);
 401                 xfree(fp);
 402                 exit(0);
 403         }
 404         if (comment)
 405                 xfree(comment);
 406
 407         f = fopen(identity_file, "r");
 408         if (f != NULL) {
 409                 while (fgets(line, sizeof(line), f)) {
 410                         i = strlen(line) - 1;
 411                         if (line[i] != '\n') {
 412                                 error("line %d too long: %.40s...", num, line);
 413                                 skip = 1;
 414                                 continue;
 415                         }
 416                         num++;
 417                         if (skip) {
 418                                 skip = 0;
 419                                 continue;
 420                         }
 421                         line[i] = '\0';
 422
 423                         /* Skip leading whitespace, empty and comment lines. */
 424                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 425                                 ;
 426                         if (!*cp || *cp == '\n' || *cp == '#')
 427                                 continue ;
 428                         i = strtol(cp, &ep, 10);
 429                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 430                                 int quoted = 0;
 431                                 comment = cp;
 432                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 433                                         if (*cp == '\\' && cp[1] == '"')
 434                                                 cp++;   /* Skip both */
 435                                         else if (*cp == '"')
 436                                                 quoted = !quoted;
 437                                 }
 438                                 if (!*cp)
 439                                         continue;
 440                                 *cp++ = '\0';
 441                         }
 442                         ep = cp;
 443                         public = key_new(KEY_RSA1);
 444                         if (key_read(public, &cp) != 1) {
 445                                 cp = ep;
 446                                 key_free(public);
 447                                 public = key_new(KEY_UNSPEC);
 448                                 if (key_read(public, &cp) != 1) {
 449                                         key_free(public);
 450                                         continue;
 451                                 }
 452                         }
 453                         comment = *cp ? cp : comment;
 454                         fp = key_fingerprint(public, fptype, rep);
 455                         printf("%d %s %s\n", key_size(public), fp,
 456                             comment ? comment : "no comment");
 457                         xfree(fp);
 458                         key_free(public);
 459                         invalid = 0;
 460                 }
 461                 fclose(f);
 462         }
 463         if (invalid) {
 464                 printf("%s is not a valid key file.\n", identity_file);
 465                 exit(1);
 466         }
 467         exit(0);
 468 }
 469
 470 /*
 471  * Perform changing a passphrase.  The argument is the passwd structure
 472  * for the current user.
 473  */
 474 void
 475 do_change_passphrase(struct passwd *pw)
 476 {
 477         char *comment;
 478         char *old_passphrase, *passphrase1, *passphrase2;
 479         struct stat st;
 480         Key *private;
 481
 482         if (!have_identity)
 483                 ask_filename(pw, "Enter file in which the key is");
 484         if (stat(identity_file, &st) < 0) {
 485                 perror(identity_file);
 486                 exit(1);
 487         }
 488         /* Try to load the file with empty passphrase. */
 489         private = key_load_private(identity_file, "", &comment);
 490         if (private == NULL) {
 491                 if (identity_passphrase)
 492                         old_passphrase = xstrdup(identity_passphrase);
 493                 else
 494                         old_passphrase = read_passphrase("Enter old passphrase: ", 1);
 495                 private = key_load_private(identity_file, old_passphrase , &comment);
 496                 memset(old_passphrase, 0, strlen(old_passphrase));
 497                 xfree(old_passphrase);
 498                 if (private == NULL) {
 499                         printf("Bad passphrase.\n");
 500                         exit(1);
 501                 }
 502         }
 503         printf("Key has comment '%s'\n", comment);
 504
 505         /* Ask the new passphrase (twice). */
 506         if (identity_new_passphrase) {
 507                 passphrase1 = xstrdup(identity_new_passphrase);
 508                 passphrase2 = NULL;
 509         } else {
 510                 passphrase1 =
 511                         read_passphrase("Enter new passphrase (empty for no passphrase): ", 1);
 512                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 513
 514                 /* Verify that they are the same. */
 515                 if (strcmp(passphrase1, passphrase2) != 0) {
 516                         memset(passphrase1, 0, strlen(passphrase1));
 517                         memset(passphrase2, 0, strlen(passphrase2));
 518                         xfree(passphrase1);
 519                         xfree(passphrase2);
 520                         printf("Pass phrases do not match.  Try again.\n");
 521                         exit(1);
 522                 }
 523                 /* Destroy the other copy. */
 524                 memset(passphrase2, 0, strlen(passphrase2));
 525                 xfree(passphrase2);
 526         }
 527
 528         /* Save the file using the new passphrase. */
 529         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 530                 printf("Saving the key failed: %s.\n", identity_file);
 531                 memset(passphrase1, 0, strlen(passphrase1));
 532                 xfree(passphrase1);
 533                 key_free(private);
 534                 xfree(comment);
 535                 exit(1);
 536         }
 537         /* Destroy the passphrase and the copy of the key in memory. */
 538         memset(passphrase1, 0, strlen(passphrase1));
 539         xfree(passphrase1);
 540         key_free(private);               /* Destroys contents */
 541         xfree(comment);
 542
 543         printf("Your identification has been saved with the new passphrase.\n");
 544         exit(0);
 545 }
 546
 547 /*
 548  * Change the comment of a private key file.
 549  */
 550 void
 551 do_change_comment(struct passwd *pw)
 552 {
 553         char new_comment[1024], *comment, *passphrase;
 554         Key *private;
 555         Key *public;
 556         struct stat st;
 557         FILE *f;
 558         int fd;
 559
 560         if (!have_identity)
 561                 ask_filename(pw, "Enter file in which the key is");
 562         if (stat(identity_file, &st) < 0) {
 563                 perror(identity_file);
 564                 exit(1);
 565         }
 566         private = key_load_private(identity_file, "", &comment);
 567         if (private == NULL) {
 568                 if (identity_passphrase)
 569                         passphrase = xstrdup(identity_passphrase);
 570                 else if (identity_new_passphrase)
 571                         passphrase = xstrdup(identity_new_passphrase);
 572                 else
 573                         passphrase = read_passphrase("Enter passphrase: ", 1);
 574                 /* Try to load using the passphrase. */
 575                 private = key_load_private(identity_file, passphrase, &comment);
 576                 if (private == NULL) {
 577                         memset(passphrase, 0, strlen(passphrase));
 578                         xfree(passphrase);
 579                         printf("Bad passphrase.\n");
 580                         exit(1);
 581                 }
 582         } else {
 583                 passphrase = xstrdup("");
 584         }
 585         if (private->type != KEY_RSA1) {
 586                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 587                 key_free(private);
 588                 exit(1);
 589         }
 590         printf("Key now has comment '%s'\n", comment);
 591
 592         if (identity_comment) {
 593                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 594         } else {
 595                 printf("Enter new comment: ");
 596                 fflush(stdout);
 597                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 598                         memset(passphrase, 0, strlen(passphrase));
 599                         key_free(private);
 600                         exit(1);
 601                 }
 602                 if (strchr(new_comment, '\n'))
 603                         *strchr(new_comment, '\n') = 0;
 604         }
 605
 606         /* Save the file using the new passphrase. */
 607         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 608                 printf("Saving the key failed: %s.\n", identity_file);
 609                 memset(passphrase, 0, strlen(passphrase));
 610                 xfree(passphrase);
 611                 key_free(private);
 612                 xfree(comment);
 613                 exit(1);
 614         }
 615         memset(passphrase, 0, strlen(passphrase));
 616         xfree(passphrase);
 617         public = key_from_private(private);
 618         key_free(private);
 619
 620         strlcat(identity_file, ".pub", sizeof(identity_file));
 621         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 622         if (fd == -1) {
 623                 printf("Could not save your public key in %s\n", identity_file);
 624                 exit(1);
 625         }
 626         f = fdopen(fd, "w");
 627         if (f == NULL) {
 628                 printf("fdopen %s failed", identity_file);
 629                 exit(1);
 630         }
 631         if (!key_write(public, f))
 632                 fprintf(stderr, "write key failed");
 633         key_free(public);
 634         fprintf(f, " %s\n", new_comment);
 635         fclose(f);
 636
 637         xfree(comment);
 638
 639         printf("The comment in your key file has been changed.\n");
 640         exit(0);
 641 }
 642
 643 void
 644 usage(void)
 645 {
 646         printf("Usage: %s [-ceilpqyB] [-t type] [-b bits] [-f file] [-C comment] "
 647             "[-N new-pass] [-P pass]\n", __progname);
 648         exit(1);
 649 }
 650
 651 /*
 652  * Main program for key management.
 653  */
 654 int
 655 main(int ac, char **av)
 656 {
 657         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 658         Key *private, *public;
 659         struct passwd *pw;
 660         int opt, type, fd;
 661         struct stat st;
 662         FILE *f;
 663
 664         extern int optind;
 665         extern char *optarg;
 666
 667         __progname = get_progname(av[0]);
 668         init_rng();
 669         seed_rng();
 670
 671         SSLeay_add_all_algorithms();
 672
 673         /* we need this for the home * directory.  */
 674         pw = getpwuid(getuid());
 675         if (!pw) {
 676                 printf("You don't exist, go away!\n");
 677                 exit(1);
 678         }
 679         if (gethostname(hostname, sizeof(hostname)) < 0) {
 680                 perror("gethostname");
 681                 exit(1);
 682         }
 683
 684         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:P:N:C:")) != -1) {
 685                 switch (opt) {
 686                 case 'b':
 687                         bits = atoi(optarg);
 688                         if (bits < 512 || bits > 32768) {
 689                                 printf("Bits has bad value.\n");
 690                                 exit(1);
 691                         }
 692                         break;
 693
 694                 case 'l':
 695                         print_fingerprint = 1;
 696                         break;
 697
 698                 case 'B':
 699                         print_bubblebabble = 1;
 700                         break;
 701
 702                 case 'p':
 703                         change_passphrase = 1;
 704                         break;
 705
 706                 case 'c':
 707                         change_comment = 1;
 708                         break;
 709
 710                 case 'f':
 711                         strlcpy(identity_file, optarg, sizeof(identity_file));
 712                         have_identity = 1;
 713                         break;
 714
 715                 case 'P':
 716                         identity_passphrase = optarg;
 717                         break;
 718
 719                 case 'N':
 720                         identity_new_passphrase = optarg;
 721                         break;
 722
 723                 case 'C':
 724                         identity_comment = optarg;
 725                         break;
 726
 727                 case 'q':
 728                         quiet = 1;
 729                         break;
 730
 731                 case 'R':
 732                         /* unused */
 733                         exit(0);
 734                         break;
 735
 736                 case 'e':
 737                 case 'x':
 738                         /* export key */
 739                         convert_to_ssh2 = 1;
 740                         break;
 741
 742                 case 'i':
 743                 case 'X':
 744                         /* import key */
 745                         convert_from_ssh2 = 1;
 746                         break;
 747
 748                 case 'y':
 749                         print_public = 1;
 750                         break;
 751
 752                 case 'd':
 753                         key_type_name = "dsa";
 754                         break;
 755
 756                 case 't':
 757                         key_type_name = optarg;
 758                         break;
 759
 760                 case '?':
 761                 default:
 762                         usage();
 763                 }
 764         }
 765         if (optind < ac) {
 766                 printf("Too many arguments.\n");
 767                 usage();
 768         }
 769         if (change_passphrase && change_comment) {
 770                 printf("Can only have one of -p and -c.\n");
 771                 usage();
 772         }
 773         if (print_fingerprint || print_bubblebabble)
 774                 do_fingerprint(pw);
 775         if (change_passphrase)
 776                 do_change_passphrase(pw);
 777         if (change_comment)
 778                 do_change_comment(pw);
 779         if (convert_to_ssh2)
 780                 do_convert_to_ssh2(pw);
 781         if (convert_from_ssh2)
 782                 do_convert_from_ssh2(pw);
 783         if (print_public)
 784                 do_print_public(pw);
 785
 786         arc4random_stir();
 787
 788         type = key_type_from_name(key_type_name);
 789         if (type == KEY_UNSPEC) {
 790                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 791                 exit(1);
 792         }
 793         if (!quiet)
 794                 printf("Generating public/private %s key pair.\n", key_type_name);
 795         private = key_generate(type, bits);
 796         if (private == NULL) {
 797                 fprintf(stderr, "key_generate failed");
 798                 exit(1);
 799         }
 800         public  = key_from_private(private);
 801
 802         if (!have_identity)
 803                 ask_filename(pw, "Enter file in which to save the key");
 804
 805         /* Create ~/.ssh directory if it doesn\'t already exist. */
 806         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 807         if (strstr(identity_file, dotsshdir) != NULL &&
 808             stat(dotsshdir, &st) < 0) {
 809                 if (mkdir(dotsshdir, 0700) < 0)
 810                         error("Could not create directory '%s'.", dotsshdir);
 811                 else if (!quiet)
 812                         printf("Created directory '%s'.\n", dotsshdir);
 813         }
 814         /* If the file already exists, ask the user to confirm. */
 815         if (stat(identity_file, &st) >= 0) {
 816                 char yesno[3];
 817                 printf("%s already exists.\n", identity_file);
 818                 printf("Overwrite (y/n)? ");
 819                 fflush(stdout);
 820                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 821                         exit(1);
 822                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 823                         exit(1);
 824         }
 825         /* Ask for a passphrase (twice). */
 826         if (identity_passphrase)
 827                 passphrase1 = xstrdup(identity_passphrase);
 828         else if (identity_new_passphrase)
 829                 passphrase1 = xstrdup(identity_new_passphrase);
 830         else {
 831 passphrase_again:
 832                 passphrase1 =
 833                         read_passphrase("Enter passphrase (empty for no passphrase): ", 1);
 834                 passphrase2 = read_passphrase("Enter same passphrase again: ", 1);
 835                 if (strcmp(passphrase1, passphrase2) != 0) {
 836                         /* The passphrases do not match.  Clear them and retry. */
 837                         memset(passphrase1, 0, strlen(passphrase1));
 838                         memset(passphrase2, 0, strlen(passphrase2));
 839                         xfree(passphrase1);
 840                         xfree(passphrase2);
 841                         printf("Passphrases do not match.  Try again.\n");
 842                         goto passphrase_again;
 843                 }
 844                 /* Clear the other copy of the passphrase. */
 845                 memset(passphrase2, 0, strlen(passphrase2));
 846                 xfree(passphrase2);
 847         }
 848
 849         if (identity_comment) {
 850                 strlcpy(comment, identity_comment, sizeof(comment));
 851         } else {
 852                 /* Create default commend field for the passphrase. */
 853                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 854         }
 855
 856         /* Save the key with the given passphrase and comment. */
 857         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 858                 printf("Saving the key failed: %s.\n", identity_file);
 859                 memset(passphrase1, 0, strlen(passphrase1));
 860                 xfree(passphrase1);
 861                 exit(1);
 862         }
 863         /* Clear the passphrase. */
 864         memset(passphrase1, 0, strlen(passphrase1));
 865         xfree(passphrase1);
 866
 867         /* Clear the private key and the random number generator. */
 868         key_free(private);
 869         arc4random_stir();
 870
 871         if (!quiet)
 872                 printf("Your identification has been saved in %s.\n", identity_file);
 873
 874         strlcat(identity_file, ".pub", sizeof(identity_file));
 875         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 876         if (fd == -1) {
 877                 printf("Could not save your public key in %s\n", identity_file);
 878                 exit(1);
 879         }
 880         f = fdopen(fd, "w");
 881         if (f == NULL) {
 882                 printf("fdopen %s failed", identity_file);
 883                 exit(1);
 884         }
 885         if (!key_write(public, f))
 886                 fprintf(stderr, "write key failed");
 887         fprintf(f, " %s\n", comment);
 888         fclose(f);
 889
 890         if (!quiet) {
 891                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 892                 printf("Your public key has been saved in %s.\n",
 893                     identity_file);
 894                 printf("The key fingerprint is:\n");
 895                 printf("%s %s\n", fp, comment);
 896                 xfree(fp);
 897         }
 898
 899         key_free(public);
 900         exit(0);
 901 }