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 1.106 2003/05/15 03:10:52 djm 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 #ifdef SMARTCARD
  32 #include "scard.h"
  33 #endif
  34 #ifdef DNS
  35 #include "dns.h"
  36 #endif
  37
  38 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  39 int bits = 1024;
  40
  41 /*
  42  * Flag indicating that we just want to change the passphrase.  This can be
  43  * set on the command line.
  44  */
  45 int change_passphrase = 0;
  46
  47 /*
  48  * Flag indicating that we just want to change the comment.  This can be set
  49  * on the command line.
  50  */
  51 int change_comment = 0;
  52
  53 int quiet = 0;
  54
  55 /* Flag indicating that we just want to see the key fingerprint */
  56 int print_fingerprint = 0;
  57 int print_bubblebabble = 0;
  58
  59 /* The identity file name, given on the command line or entered by the user. */
  60 char identity_file[1024];
  61 int have_identity = 0;
  62
  63 /* This is set to the passphrase if given on the command line. */
  64 char *identity_passphrase = NULL;
  65
  66 /* This is set to the new passphrase if given on the command line. */
  67 char *identity_new_passphrase = NULL;
  68
  69 /* This is set to the new comment if given on the command line. */
  70 char *identity_comment = NULL;
  71
  72 /* Dump public key file in format used by real and the original SSH 2 */
  73 int convert_to_ssh2 = 0;
  74 int convert_from_ssh2 = 0;
  75 int print_public = 0;
  76 int print_generic = 0;
  77
  78 char *key_type_name = NULL;
  79
  80 /* argv0 */
  81 #ifdef HAVE___PROGNAME
  82 extern char *__progname;
  83 #else
  84 char *__progname;
  85 #endif
  86
  87 char hostname[MAXHOSTNAMELEN];
  88
  89 static void
  90 ask_filename(struct passwd *pw, const char *prompt)
  91 {
  92         char buf[1024];
  93         char *name = NULL;
  94
  95         if (key_type_name == NULL)
  96                 name = _PATH_SSH_CLIENT_ID_RSA;
  97         else
  98                 switch (key_type_from_name(key_type_name)) {
  99                 case KEY_RSA1:
 100                         name = _PATH_SSH_CLIENT_IDENTITY;
 101                         break;
 102                 case KEY_DSA:
 103                         name = _PATH_SSH_CLIENT_ID_DSA;
 104                         break;
 105                 case KEY_RSA:
 106                         name = _PATH_SSH_CLIENT_ID_RSA;
 107                         break;
 108                 default:
 109                         fprintf(stderr, "bad key type");
 110                         exit(1);
 111                         break;
 112                 }
 113
 114         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 115         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 116         if (fgets(buf, sizeof(buf), stdin) == NULL)
 117                 exit(1);
 118         if (strchr(buf, '\n'))
 119                 *strchr(buf, '\n') = 0;
 120         if (strcmp(buf, "") != 0)
 121                 strlcpy(identity_file, buf, sizeof(identity_file));
 122         have_identity = 1;
 123 }
 124
 125 static Key *
 126 load_identity(char *filename)
 127 {
 128         char *pass;
 129         Key *prv;
 130
 131         prv = key_load_private(filename, "", NULL);
 132         if (prv == NULL) {
 133                 if (identity_passphrase)
 134                         pass = xstrdup(identity_passphrase);
 135                 else
 136                         pass = read_passphrase("Enter passphrase: ",
 137                             RP_ALLOW_STDIN);
 138                 prv = key_load_private(filename, pass, NULL);
 139                 memset(pass, 0, strlen(pass));
 140                 xfree(pass);
 141         }
 142         return prv;
 143 }
 144
 145 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 146 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 147 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 148 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 149
 150 static void
 151 do_convert_to_ssh2(struct passwd *pw)
 152 {
 153         Key *k;
 154         u_int len;
 155         u_char *blob;
 156         struct stat st;
 157
 158         if (!have_identity)
 159                 ask_filename(pw, "Enter file in which the key is");
 160         if (stat(identity_file, &st) < 0) {
 161                 perror(identity_file);
 162                 exit(1);
 163         }
 164         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 165                 if ((k = load_identity(identity_file)) == NULL) {
 166                         fprintf(stderr, "load failed\n");
 167                         exit(1);
 168                 }
 169         }
 170         if (k->type == KEY_RSA1) {
 171                 fprintf(stderr, "version 1 keys are not supported\n");
 172                 exit(1);
 173         }
 174         if (key_to_blob(k, &blob, &len) <= 0) {
 175                 fprintf(stderr, "key_to_blob failed\n");
 176                 exit(1);
 177         }
 178         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 179         fprintf(stdout,
 180             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 181             key_size(k), key_type(k),
 182             pw->pw_name, hostname);
 183         dump_base64(stdout, blob, len);
 184         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 185         key_free(k);
 186         xfree(blob);
 187         exit(0);
 188 }
 189
 190 static void
 191 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 192 {
 193         int bits = buffer_get_int(b);
 194         int bytes = (bits + 7) / 8;
 195
 196         if (buffer_len(b) < bytes)
 197                 fatal("buffer_get_bignum_bits: input buffer too small: "
 198                     "need %d have %d", bytes, buffer_len(b));
 199         BN_bin2bn(buffer_ptr(b), bytes, value);
 200         buffer_consume(b, bytes);
 201 }
 202
 203 static Key *
 204 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 205 {
 206         Buffer b;
 207         Key *key = NULL;
 208         char *type, *cipher;
 209         u_char *sig, data[] = "abcde12345";
 210         int magic, rlen, ktype, i1, i2, i3, i4;
 211         u_int slen;
 212         u_long e;
 213
 214         buffer_init(&b);
 215         buffer_append(&b, blob, blen);
 216
 217         magic  = buffer_get_int(&b);
 218         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 219                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 220                 buffer_free(&b);
 221                 return NULL;
 222         }
 223         i1 = buffer_get_int(&b);
 224         type   = buffer_get_string(&b, NULL);
 225         cipher = buffer_get_string(&b, NULL);
 226         i2 = buffer_get_int(&b);
 227         i3 = buffer_get_int(&b);
 228         i4 = buffer_get_int(&b);
 229         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 230         if (strcmp(cipher, "none") != 0) {
 231                 error("unsupported cipher %s", cipher);
 232                 xfree(cipher);
 233                 buffer_free(&b);
 234                 xfree(type);
 235                 return NULL;
 236         }
 237         xfree(cipher);
 238
 239         if (strstr(type, "dsa")) {
 240                 ktype = KEY_DSA;
 241         } else if (strstr(type, "rsa")) {
 242                 ktype = KEY_RSA;
 243         } else {
 244                 xfree(type);
 245                 return NULL;
 246         }
 247         key = key_new_private(ktype);
 248         xfree(type);
 249
 250         switch (key->type) {
 251         case KEY_DSA:
 252                 buffer_get_bignum_bits(&b, key->dsa->p);
 253                 buffer_get_bignum_bits(&b, key->dsa->g);
 254                 buffer_get_bignum_bits(&b, key->dsa->q);
 255                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 256                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 257                 break;
 258         case KEY_RSA:
 259                 e  = buffer_get_char(&b);
 260                 debug("e %lx", e);
 261                 if (e < 30) {
 262                         e <<= 8;
 263                         e += buffer_get_char(&b);
 264                         debug("e %lx", e);
 265                         e <<= 8;
 266                         e += buffer_get_char(&b);
 267                         debug("e %lx", e);
 268                 }
 269                 if (!BN_set_word(key->rsa->e, e)) {
 270                         buffer_free(&b);
 271                         key_free(key);
 272                         return NULL;
 273                 }
 274                 buffer_get_bignum_bits(&b, key->rsa->d);
 275                 buffer_get_bignum_bits(&b, key->rsa->n);
 276                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 277                 buffer_get_bignum_bits(&b, key->rsa->q);
 278                 buffer_get_bignum_bits(&b, key->rsa->p);
 279                 rsa_generate_additional_parameters(key->rsa);
 280                 break;
 281         }
 282         rlen = buffer_len(&b);
 283         if (rlen != 0)
 284                 error("do_convert_private_ssh2_from_blob: "
 285                     "remaining bytes in key blob %d", rlen);
 286         buffer_free(&b);
 287
 288         /* try the key */
 289         key_sign(key, &sig, &slen, data, sizeof(data));
 290         key_verify(key, sig, slen, data, sizeof(data));
 291         xfree(sig);
 292         return key;
 293 }
 294
 295 static void
 296 do_convert_from_ssh2(struct passwd *pw)
 297 {
 298         Key *k;
 299         int blen;
 300         u_int len;
 301         char line[1024], *p;
 302         u_char blob[8096];
 303         char encoded[8096];
 304         struct stat st;
 305         int escaped = 0, private = 0, ok;
 306         FILE *fp;
 307
 308         if (!have_identity)
 309                 ask_filename(pw, "Enter file in which the key is");
 310         if (stat(identity_file, &st) < 0) {
 311                 perror(identity_file);
 312                 exit(1);
 313         }
 314         fp = fopen(identity_file, "r");
 315         if (fp == NULL) {
 316                 perror(identity_file);
 317                 exit(1);
 318         }
 319         encoded[0] = '\0';
 320         while (fgets(line, sizeof(line), fp)) {
 321                 if (!(p = strchr(line, '\n'))) {
 322                         fprintf(stderr, "input line too long.\n");
 323                         exit(1);
 324                 }
 325                 if (p > line && p[-1] == '\\')
 326                         escaped++;
 327                 if (strncmp(line, "----", 4) == 0 ||
 328                     strstr(line, ": ") != NULL) {
 329                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 330                                 private = 1;
 331                         if (strstr(line, " END ") != NULL) {
 332                                 break;
 333                         }
 334                         /* fprintf(stderr, "ignore: %s", line); */
 335                         continue;
 336                 }
 337                 if (escaped) {
 338                         escaped--;
 339                         /* fprintf(stderr, "escaped: %s", line); */
 340                         continue;
 341                 }
 342                 *p = '\0';
 343                 strlcat(encoded, line, sizeof(encoded));
 344         }
 345         len = strlen(encoded);
 346         if (((len % 4) == 3) &&
 347             (encoded[len-1] == '=') &&
 348             (encoded[len-2] == '=') &&
 349             (encoded[len-3] == '='))
 350                 encoded[len-3] = '\0';
 351         blen = uudecode(encoded, blob, sizeof(blob));
 352         if (blen < 0) {
 353                 fprintf(stderr, "uudecode failed.\n");
 354                 exit(1);
 355         }
 356         k = private ?
 357             do_convert_private_ssh2_from_blob(blob, blen) :
 358             key_from_blob(blob, blen);
 359         if (k == NULL) {
 360                 fprintf(stderr, "decode blob failed.\n");
 361                 exit(1);
 362         }
 363         ok = private ?
 364             (k->type == KEY_DSA ?
 365                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 366                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 367             key_write(k, stdout);
 368         if (!ok) {
 369                 fprintf(stderr, "key write failed");
 370                 exit(1);
 371         }
 372         key_free(k);
 373         if (!private)
 374                 fprintf(stdout, "\n");
 375         fclose(fp);
 376         exit(0);
 377 }
 378
 379 static void
 380 do_print_public(struct passwd *pw)
 381 {
 382         Key *prv;
 383         struct stat st;
 384
 385         if (!have_identity)
 386                 ask_filename(pw, "Enter file in which the key is");
 387         if (stat(identity_file, &st) < 0) {
 388                 perror(identity_file);
 389                 exit(1);
 390         }
 391         prv = load_identity(identity_file);
 392         if (prv == NULL) {
 393                 fprintf(stderr, "load failed\n");
 394                 exit(1);
 395         }
 396         if (!key_write(prv, stdout))
 397                 fprintf(stderr, "key_write failed");
 398         key_free(prv);
 399         fprintf(stdout, "\n");
 400         exit(0);
 401 }
 402
 403 #ifdef SMARTCARD
 404 static void
 405 do_upload(struct passwd *pw, const char *sc_reader_id)
 406 {
 407         Key *prv = NULL;
 408         struct stat st;
 409         int ret;
 410
 411         if (!have_identity)
 412                 ask_filename(pw, "Enter file in which the key is");
 413         if (stat(identity_file, &st) < 0) {
 414                 perror(identity_file);
 415                 exit(1);
 416         }
 417         prv = load_identity(identity_file);
 418         if (prv == NULL) {
 419                 error("load failed");
 420                 exit(1);
 421         }
 422         ret = sc_put_key(prv, sc_reader_id);
 423         key_free(prv);
 424         if (ret < 0)
 425                 exit(1);
 426         logit("loading key done");
 427         exit(0);
 428 }
 429
 430 static void
 431 do_download(struct passwd *pw, const char *sc_reader_id)
 432 {
 433         Key **keys = NULL;
 434         int i;
 435
 436         keys = sc_get_keys(sc_reader_id, NULL);
 437         if (keys == NULL)
 438                 fatal("cannot read public key from smartcard");
 439         for (i = 0; keys[i]; i++) {
 440                 key_write(keys[i], stdout);
 441                 key_free(keys[i]);
 442                 fprintf(stdout, "\n");
 443         }
 444         xfree(keys);
 445         exit(0);
 446 }
 447 #endif /* SMARTCARD */
 448
 449 static void
 450 do_fingerprint(struct passwd *pw)
 451 {
 452         FILE *f;
 453         Key *public;
 454         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 455         int i, skip = 0, num = 1, invalid = 1;
 456         enum fp_rep rep;
 457         enum fp_type fptype;
 458         struct stat st;
 459
 460         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 461         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 462
 463         if (!have_identity)
 464                 ask_filename(pw, "Enter file in which the key is");
 465         if (stat(identity_file, &st) < 0) {
 466                 perror(identity_file);
 467                 exit(1);
 468         }
 469         public = key_load_public(identity_file, &comment);
 470         if (public != NULL) {
 471                 fp = key_fingerprint(public, fptype, rep);
 472                 printf("%u %s %s\n", key_size(public), fp, comment);
 473                 key_free(public);
 474                 xfree(comment);
 475                 xfree(fp);
 476                 exit(0);
 477         }
 478         if (comment)
 479                 xfree(comment);
 480
 481         f = fopen(identity_file, "r");
 482         if (f != NULL) {
 483                 while (fgets(line, sizeof(line), f)) {
 484                         i = strlen(line) - 1;
 485                         if (line[i] != '\n') {
 486                                 error("line %d too long: %.40s...", num, line);
 487                                 skip = 1;
 488                                 continue;
 489                         }
 490                         num++;
 491                         if (skip) {
 492                                 skip = 0;
 493                                 continue;
 494                         }
 495                         line[i] = '\0';
 496
 497                         /* Skip leading whitespace, empty and comment lines. */
 498                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 499                                 ;
 500                         if (!*cp || *cp == '\n' || *cp == '#')
 501                                 continue ;
 502                         i = strtol(cp, &ep, 10);
 503                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 504                                 int quoted = 0;
 505                                 comment = cp;
 506                                 for (; *cp && (quoted || (*cp != ' ' &&
 507                                     *cp != '\t')); cp++) {
 508                                         if (*cp == '\\' && cp[1] == '"')
 509                                                 cp++;   /* Skip both */
 510                                         else if (*cp == '"')
 511                                                 quoted = !quoted;
 512                                 }
 513                                 if (!*cp)
 514                                         continue;
 515                                 *cp++ = '\0';
 516                         }
 517                         ep = cp;
 518                         public = key_new(KEY_RSA1);
 519                         if (key_read(public, &cp) != 1) {
 520                                 cp = ep;
 521                                 key_free(public);
 522                                 public = key_new(KEY_UNSPEC);
 523                                 if (key_read(public, &cp) != 1) {
 524                                         key_free(public);
 525                                         continue;
 526                                 }
 527                         }
 528                         comment = *cp ? cp : comment;
 529                         fp = key_fingerprint(public, fptype, rep);
 530                         printf("%u %s %s\n", key_size(public), fp,
 531                             comment ? comment : "no comment");
 532                         xfree(fp);
 533                         key_free(public);
 534                         invalid = 0;
 535                 }
 536                 fclose(f);
 537         }
 538         if (invalid) {
 539                 printf("%s is not a public key file.\n", identity_file);
 540                 exit(1);
 541         }
 542         exit(0);
 543 }
 544
 545 /*
 546  * Perform changing a passphrase.  The argument is the passwd structure
 547  * for the current user.
 548  */
 549 static void
 550 do_change_passphrase(struct passwd *pw)
 551 {
 552         char *comment;
 553         char *old_passphrase, *passphrase1, *passphrase2;
 554         struct stat st;
 555         Key *private;
 556
 557         if (!have_identity)
 558                 ask_filename(pw, "Enter file in which the key is");
 559         if (stat(identity_file, &st) < 0) {
 560                 perror(identity_file);
 561                 exit(1);
 562         }
 563         /* Try to load the file with empty passphrase. */
 564         private = key_load_private(identity_file, "", &comment);
 565         if (private == NULL) {
 566                 if (identity_passphrase)
 567                         old_passphrase = xstrdup(identity_passphrase);
 568                 else
 569                         old_passphrase =
 570                             read_passphrase("Enter old passphrase: ",
 571                             RP_ALLOW_STDIN);
 572                 private = key_load_private(identity_file, old_passphrase,
 573                     &comment);
 574                 memset(old_passphrase, 0, strlen(old_passphrase));
 575                 xfree(old_passphrase);
 576                 if (private == NULL) {
 577                         printf("Bad passphrase.\n");
 578                         exit(1);
 579                 }
 580         }
 581         printf("Key has comment '%s'\n", comment);
 582
 583         /* Ask the new passphrase (twice). */
 584         if (identity_new_passphrase) {
 585                 passphrase1 = xstrdup(identity_new_passphrase);
 586                 passphrase2 = NULL;
 587         } else {
 588                 passphrase1 =
 589                         read_passphrase("Enter new passphrase (empty for no "
 590                             "passphrase): ", RP_ALLOW_STDIN);
 591                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 592                     RP_ALLOW_STDIN);
 593
 594                 /* Verify that they are the same. */
 595                 if (strcmp(passphrase1, passphrase2) != 0) {
 596                         memset(passphrase1, 0, strlen(passphrase1));
 597                         memset(passphrase2, 0, strlen(passphrase2));
 598                         xfree(passphrase1);
 599                         xfree(passphrase2);
 600                         printf("Pass phrases do not match.  Try again.\n");
 601                         exit(1);
 602                 }
 603                 /* Destroy the other copy. */
 604                 memset(passphrase2, 0, strlen(passphrase2));
 605                 xfree(passphrase2);
 606         }
 607
 608         /* Save the file using the new passphrase. */
 609         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 610                 printf("Saving the key failed: %s.\n", identity_file);
 611                 memset(passphrase1, 0, strlen(passphrase1));
 612                 xfree(passphrase1);
 613                 key_free(private);
 614                 xfree(comment);
 615                 exit(1);
 616         }
 617         /* Destroy the passphrase and the copy of the key in memory. */
 618         memset(passphrase1, 0, strlen(passphrase1));
 619         xfree(passphrase1);
 620         key_free(private);               /* Destroys contents */
 621         xfree(comment);
 622
 623         printf("Your identification has been saved with the new passphrase.\n");
 624         exit(0);
 625 }
 626
 627 #ifdef DNS
 628 /*
 629  * Print the SSHFP RR.
 630  */
 631 static void
 632 do_print_resource_record(struct passwd *pw, char *hostname)
 633 {
 634         Key *public;
 635         char *comment = NULL;
 636         struct stat st;
 637
 638         if (!have_identity)
 639                 ask_filename(pw, "Enter file in which the key is");
 640         if (stat(identity_file, &st) < 0) {
 641                 perror(identity_file);
 642                 exit(1);
 643         }
 644         public = key_load_public(identity_file, &comment);
 645         if (public != NULL) {
 646                 export_dns_rr(hostname, public, stdout, print_generic);
 647                 key_free(public);
 648                 xfree(comment);
 649                 exit(0);
 650         }
 651         if (comment)
 652                 xfree(comment);
 653
 654         printf("failed to read v2 public key from %s.\n", identity_file);
 655         exit(1);
 656 }
 657 #endif /* DNS */
 658
 659 /*
 660  * Change the comment of a private key file.
 661  */
 662 static void
 663 do_change_comment(struct passwd *pw)
 664 {
 665         char new_comment[1024], *comment, *passphrase;
 666         Key *private;
 667         Key *public;
 668         struct stat st;
 669         FILE *f;
 670         int fd;
 671
 672         if (!have_identity)
 673                 ask_filename(pw, "Enter file in which the key is");
 674         if (stat(identity_file, &st) < 0) {
 675                 perror(identity_file);
 676                 exit(1);
 677         }
 678         private = key_load_private(identity_file, "", &comment);
 679         if (private == NULL) {
 680                 if (identity_passphrase)
 681                         passphrase = xstrdup(identity_passphrase);
 682                 else if (identity_new_passphrase)
 683                         passphrase = xstrdup(identity_new_passphrase);
 684                 else
 685                         passphrase = read_passphrase("Enter passphrase: ",
 686                             RP_ALLOW_STDIN);
 687                 /* Try to load using the passphrase. */
 688                 private = key_load_private(identity_file, passphrase, &comment);
 689                 if (private == NULL) {
 690                         memset(passphrase, 0, strlen(passphrase));
 691                         xfree(passphrase);
 692                         printf("Bad passphrase.\n");
 693                         exit(1);
 694                 }
 695         } else {
 696                 passphrase = xstrdup("");
 697         }
 698         if (private->type != KEY_RSA1) {
 699                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 700                 key_free(private);
 701                 exit(1);
 702         }
 703         printf("Key now has comment '%s'\n", comment);
 704
 705         if (identity_comment) {
 706                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 707         } else {
 708                 printf("Enter new comment: ");
 709                 fflush(stdout);
 710                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 711                         memset(passphrase, 0, strlen(passphrase));
 712                         key_free(private);
 713                         exit(1);
 714                 }
 715                 if (strchr(new_comment, '\n'))
 716                         *strchr(new_comment, '\n') = 0;
 717         }
 718
 719         /* Save the file using the new passphrase. */
 720         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 721                 printf("Saving the key failed: %s.\n", identity_file);
 722                 memset(passphrase, 0, strlen(passphrase));
 723                 xfree(passphrase);
 724                 key_free(private);
 725                 xfree(comment);
 726                 exit(1);
 727         }
 728         memset(passphrase, 0, strlen(passphrase));
 729         xfree(passphrase);
 730         public = key_from_private(private);
 731         key_free(private);
 732
 733         strlcat(identity_file, ".pub", sizeof(identity_file));
 734         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 735         if (fd == -1) {
 736                 printf("Could not save your public key in %s\n", identity_file);
 737                 exit(1);
 738         }
 739         f = fdopen(fd, "w");
 740         if (f == NULL) {
 741                 printf("fdopen %s failed", identity_file);
 742                 exit(1);
 743         }
 744         if (!key_write(public, f))
 745                 fprintf(stderr, "write key failed");
 746         key_free(public);
 747         fprintf(f, " %s\n", new_comment);
 748         fclose(f);
 749
 750         xfree(comment);
 751
 752         printf("The comment in your key file has been changed.\n");
 753         exit(0);
 754 }
 755
 756 static void
 757 usage(void)
 758 {
 759         fprintf(stderr, "Usage: %s [options]\n", __progname);
 760         fprintf(stderr, "Options:\n");
 761         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 762         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 763         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 764         fprintf(stderr, "  -f filename Filename of the key file.\n");
 765         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
 766         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 767         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 768         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 769         fprintf(stderr, "  -q          Quiet.\n");
 770         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 771         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 772         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 773         fprintf(stderr, "  -C comment  Provide new comment.\n");
 774         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 775         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 776 #ifdef DNS
 777         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
 778 #endif /* DNS */
 779 #ifdef SMARTCARD
 780         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 781         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 782 #endif /* SMARTCARD */
 783
 784         exit(1);
 785 }
 786
 787 /*
 788  * Main program for key management.
 789  */
 790 int
 791 main(int ac, char **av)
 792 {
 793         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 794         char *reader_id = NULL;
 795         char *resource_record_hostname = NULL;
 796         Key *private, *public;
 797         struct passwd *pw;
 798         struct stat st;
 799         int opt, type, fd, download = 0;
 800         FILE *f;
 801
 802         extern int optind;
 803         extern char *optarg;
 804
 805         __progname = get_progname(av[0]);
 806
 807         SSLeay_add_all_algorithms();
 808         init_rng();
 809         seed_rng();
 810
 811         /* we need this for the home * directory.  */
 812         pw = getpwuid(getuid());
 813         if (!pw) {
 814                 printf("You don't exist, go away!\n");
 815                 exit(1);
 816         }
 817         if (gethostname(hostname, sizeof(hostname)) < 0) {
 818                 perror("gethostname");
 819                 exit(1);
 820         }
 821
 822         while ((opt = getopt(ac, av, "degiqpclBRxXyb:f:t:U:D:P:N:C:r:")) != -1) {
 823                 switch (opt) {
 824                 case 'b':
 825                         bits = atoi(optarg);
 826                         if (bits < 512 || bits > 32768) {
 827                                 printf("Bits has bad value.\n");
 828                                 exit(1);
 829                         }
 830                         break;
 831                 case 'l':
 832                         print_fingerprint = 1;
 833                         break;
 834                 case 'B':
 835                         print_bubblebabble = 1;
 836                         break;
 837                 case 'p':
 838                         change_passphrase = 1;
 839                         break;
 840                 case 'c':
 841                         change_comment = 1;
 842                         break;
 843                 case 'f':
 844                         strlcpy(identity_file, optarg, sizeof(identity_file));
 845                         have_identity = 1;
 846                         break;
 847                 case 'g':
 848                         print_generic = 1;
 849                         break;
 850                 case 'P':
 851                         identity_passphrase = optarg;
 852                         break;
 853                 case 'N':
 854                         identity_new_passphrase = optarg;
 855                         break;
 856                 case 'C':
 857                         identity_comment = optarg;
 858                         break;
 859                 case 'q':
 860                         quiet = 1;
 861                         break;
 862                 case 'R':
 863                         /* unused */
 864                         exit(0);
 865                         break;
 866                 case 'e':
 867                 case 'x':
 868                         /* export key */
 869                         convert_to_ssh2 = 1;
 870                         break;
 871                 case 'i':
 872                 case 'X':
 873                         /* import key */
 874                         convert_from_ssh2 = 1;
 875                         break;
 876                 case 'y':
 877                         print_public = 1;
 878                         break;
 879                 case 'd':
 880                         key_type_name = "dsa";
 881                         break;
 882                 case 't':
 883                         key_type_name = optarg;
 884                         break;
 885                 case 'D':
 886                         download = 1;
 887                 case 'U':
 888                         reader_id = optarg;
 889                         break;
 890                 case 'r':
 891                         resource_record_hostname = optarg;
 892                         break;
 893                 case '?':
 894                 default:
 895                         usage();
 896                 }
 897         }
 898         if (optind < ac) {
 899                 printf("Too many arguments.\n");
 900                 usage();
 901         }
 902         if (change_passphrase && change_comment) {
 903                 printf("Can only have one of -p and -c.\n");
 904                 usage();
 905         }
 906         if (print_fingerprint || print_bubblebabble)
 907                 do_fingerprint(pw);
 908         if (change_passphrase)
 909                 do_change_passphrase(pw);
 910         if (change_comment)
 911                 do_change_comment(pw);
 912         if (convert_to_ssh2)
 913                 do_convert_to_ssh2(pw);
 914         if (convert_from_ssh2)
 915                 do_convert_from_ssh2(pw);
 916         if (print_public)
 917                 do_print_public(pw);
 918         if (resource_record_hostname != NULL) {
 919 #ifdef DNS
 920                 do_print_resource_record(pw, resource_record_hostname);
 921 #else /* DNS */
 922                 fatal("no DNS support.");
 923 #endif /* DNS */
 924         }
 925         if (reader_id != NULL) {
 926 #ifdef SMARTCARD
 927                 if (download)
 928                         do_download(pw, reader_id);
 929                 else
 930                         do_upload(pw, reader_id);
 931 #else /* SMARTCARD */
 932                 fatal("no support for smartcards.");
 933 #endif /* SMARTCARD */
 934         }
 935
 936         arc4random_stir();
 937
 938         if (key_type_name == NULL) {
 939                 printf("You must specify a key type (-t).\n");
 940                 usage();
 941         }
 942         type = key_type_from_name(key_type_name);
 943         if (type == KEY_UNSPEC) {
 944                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 945                 exit(1);
 946         }
 947         if (!quiet)
 948                 printf("Generating public/private %s key pair.\n", key_type_name);
 949         private = key_generate(type, bits);
 950         if (private == NULL) {
 951                 fprintf(stderr, "key_generate failed");
 952                 exit(1);
 953         }
 954         public  = key_from_private(private);
 955
 956         if (!have_identity)
 957                 ask_filename(pw, "Enter file in which to save the key");
 958
 959         /* Create ~/.ssh directory if it doesn\'t already exist. */
 960         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 961         if (strstr(identity_file, dotsshdir) != NULL &&
 962             stat(dotsshdir, &st) < 0) {
 963                 if (mkdir(dotsshdir, 0700) < 0)
 964                         error("Could not create directory '%s'.", dotsshdir);
 965                 else if (!quiet)
 966                         printf("Created directory '%s'.\n", dotsshdir);
 967         }
 968         /* If the file already exists, ask the user to confirm. */
 969         if (stat(identity_file, &st) >= 0) {
 970                 char yesno[3];
 971                 printf("%s already exists.\n", identity_file);
 972                 printf("Overwrite (y/n)? ");
 973                 fflush(stdout);
 974                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 975                         exit(1);
 976                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 977                         exit(1);
 978         }
 979         /* Ask for a passphrase (twice). */
 980         if (identity_passphrase)
 981                 passphrase1 = xstrdup(identity_passphrase);
 982         else if (identity_new_passphrase)
 983                 passphrase1 = xstrdup(identity_new_passphrase);
 984         else {
 985 passphrase_again:
 986                 passphrase1 =
 987                         read_passphrase("Enter passphrase (empty for no "
 988                             "passphrase): ", RP_ALLOW_STDIN);
 989                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 990                     RP_ALLOW_STDIN);
 991                 if (strcmp(passphrase1, passphrase2) != 0) {
 992                         /*
 993                          * The passphrases do not match.  Clear them and
 994                          * retry.
 995                          */
 996                         memset(passphrase1, 0, strlen(passphrase1));
 997                         memset(passphrase2, 0, strlen(passphrase2));
 998                         xfree(passphrase1);
 999                         xfree(passphrase2);
1000                         printf("Passphrases do not match.  Try again.\n");
1001                         goto passphrase_again;
1002                 }
1003                 /* Clear the other copy of the passphrase. */
1004                 memset(passphrase2, 0, strlen(passphrase2));
1005                 xfree(passphrase2);
1006         }
1007
1008         if (identity_comment) {
1009                 strlcpy(comment, identity_comment, sizeof(comment));
1010         } else {
1011                 /* Create default commend field for the passphrase. */
1012                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1013         }
1014
1015         /* Save the key with the given passphrase and comment. */
1016         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1017                 printf("Saving the key failed: %s.\n", identity_file);
1018                 memset(passphrase1, 0, strlen(passphrase1));
1019                 xfree(passphrase1);
1020                 exit(1);
1021         }
1022         /* Clear the passphrase. */
1023         memset(passphrase1, 0, strlen(passphrase1));
1024         xfree(passphrase1);
1025
1026         /* Clear the private key and the random number generator. */
1027         key_free(private);
1028         arc4random_stir();
1029
1030         if (!quiet)
1031                 printf("Your identification has been saved in %s.\n", identity_file);
1032
1033         strlcat(identity_file, ".pub", sizeof(identity_file));
1034         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1035         if (fd == -1) {
1036                 printf("Could not save your public key in %s\n", identity_file);
1037                 exit(1);
1038         }
1039         f = fdopen(fd, "w");
1040         if (f == NULL) {
1041                 printf("fdopen %s failed", identity_file);
1042                 exit(1);
1043         }
1044         if (!key_write(public, f))
1045                 fprintf(stderr, "write key failed");
1046         fprintf(f, " %s\n", comment);
1047         fclose(f);
1048
1049         if (!quiet) {
1050                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1051                 printf("Your public key has been saved in %s.\n",
1052                     identity_file);
1053                 printf("The key fingerprint is:\n");
1054                 printf("%s %s\n", fp, comment);
1055                 xfree(fp);
1056         }
1057
1058         key_free(public);
1059         exit(0);
1060 }