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 1.103 2003/04/08 20:21:29 itojun 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
  35 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  36 int bits = 1024;
  37
  38 /*
  39  * Flag indicating that we just want to change the passphrase.  This can be
  40  * set on the command line.
  41  */
  42 int change_passphrase = 0;
  43
  44 /*
  45  * Flag indicating that we just want to change the comment.  This can be set
  46  * on the command line.
  47  */
  48 int change_comment = 0;
  49
  50 int quiet = 0;
  51
  52 /* Flag indicating that we just want to see the key fingerprint */
  53 int print_fingerprint = 0;
  54 int print_bubblebabble = 0;
  55
  56 /* The identity file name, given on the command line or entered by the user. */
  57 char identity_file[1024];
  58 int have_identity = 0;
  59
  60 /* This is set to the passphrase if given on the command line. */
  61 char *identity_passphrase = NULL;
  62
  63 /* This is set to the new passphrase if given on the command line. */
  64 char *identity_new_passphrase = NULL;
  65
  66 /* This is set to the new comment if given on the command line. */
  67 char *identity_comment = NULL;
  68
  69 /* Dump public key file in format used by real and the original SSH 2 */
  70 int convert_to_ssh2 = 0;
  71 int convert_from_ssh2 = 0;
  72 int print_public = 0;
  73
  74 char *key_type_name = NULL;
  75
  76 /* argv0 */
  77 #ifdef HAVE___PROGNAME
  78 extern char *__progname;
  79 #else
  80 char *__progname;
  81 #endif
  82
  83 char hostname[MAXHOSTNAMELEN];
  84
  85 static void
  86 ask_filename(struct passwd *pw, const char *prompt)
  87 {
  88         char buf[1024];
  89         char *name = NULL;
  90
  91         if (key_type_name == NULL)
  92                 name = _PATH_SSH_CLIENT_ID_RSA;
  93         else
  94                 switch (key_type_from_name(key_type_name)) {
  95                 case KEY_RSA1:
  96                         name = _PATH_SSH_CLIENT_IDENTITY;
  97                         break;
  98                 case KEY_DSA:
  99                         name = _PATH_SSH_CLIENT_ID_DSA;
 100                         break;
 101                 case KEY_RSA:
 102                         name = _PATH_SSH_CLIENT_ID_RSA;
 103                         break;
 104                 default:
 105                         fprintf(stderr, "bad key type");
 106                         exit(1);
 107                         break;
 108                 }
 109
 110         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 111         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 112         if (fgets(buf, sizeof(buf), stdin) == NULL)
 113                 exit(1);
 114         if (strchr(buf, '\n'))
 115                 *strchr(buf, '\n') = 0;
 116         if (strcmp(buf, "") != 0)
 117                 strlcpy(identity_file, buf, sizeof(identity_file));
 118         have_identity = 1;
 119 }
 120
 121 static Key *
 122 load_identity(char *filename)
 123 {
 124         char *pass;
 125         Key *prv;
 126
 127         prv = key_load_private(filename, "", NULL);
 128         if (prv == NULL) {
 129                 if (identity_passphrase)
 130                         pass = xstrdup(identity_passphrase);
 131                 else
 132                         pass = read_passphrase("Enter passphrase: ",
 133                             RP_ALLOW_STDIN);
 134                 prv = key_load_private(filename, pass, NULL);
 135                 memset(pass, 0, strlen(pass));
 136                 xfree(pass);
 137         }
 138         return prv;
 139 }
 140
 141 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 142 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 143 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 144 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 145
 146 static void
 147 do_convert_to_ssh2(struct passwd *pw)
 148 {
 149         Key *k;
 150         u_int len;
 151         u_char *blob;
 152         struct stat st;
 153
 154         if (!have_identity)
 155                 ask_filename(pw, "Enter file in which the key is");
 156         if (stat(identity_file, &st) < 0) {
 157                 perror(identity_file);
 158                 exit(1);
 159         }
 160         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 161                 if ((k = load_identity(identity_file)) == NULL) {
 162                         fprintf(stderr, "load failed\n");
 163                         exit(1);
 164                 }
 165         }
 166         if (key_to_blob(k, &blob, &len) <= 0) {
 167                 fprintf(stderr, "key_to_blob failed\n");
 168                 exit(1);
 169         }
 170         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 171         fprintf(stdout,
 172             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 173             key_size(k), key_type(k),
 174             pw->pw_name, hostname);
 175         dump_base64(stdout, blob, len);
 176         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 177         key_free(k);
 178         xfree(blob);
 179         exit(0);
 180 }
 181
 182 static void
 183 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 184 {
 185         int bits = buffer_get_int(b);
 186         int bytes = (bits + 7) / 8;
 187
 188         if (buffer_len(b) < bytes)
 189                 fatal("buffer_get_bignum_bits: input buffer too small: "
 190                     "need %d have %d", bytes, buffer_len(b));
 191         BN_bin2bn(buffer_ptr(b), bytes, value);
 192         buffer_consume(b, bytes);
 193 }
 194
 195 static Key *
 196 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 197 {
 198         Buffer b;
 199         Key *key = NULL;
 200         char *type, *cipher;
 201         u_char *sig, data[] = "abcde12345";
 202         int magic, rlen, ktype, i1, i2, i3, i4;
 203         u_int slen;
 204         u_long e;
 205
 206         buffer_init(&b);
 207         buffer_append(&b, blob, blen);
 208
 209         magic  = buffer_get_int(&b);
 210         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 211                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 212                 buffer_free(&b);
 213                 return NULL;
 214         }
 215         i1 = buffer_get_int(&b);
 216         type   = buffer_get_string(&b, NULL);
 217         cipher = buffer_get_string(&b, NULL);
 218         i2 = buffer_get_int(&b);
 219         i3 = buffer_get_int(&b);
 220         i4 = buffer_get_int(&b);
 221         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 222         if (strcmp(cipher, "none") != 0) {
 223                 error("unsupported cipher %s", cipher);
 224                 xfree(cipher);
 225                 buffer_free(&b);
 226                 xfree(type);
 227                 return NULL;
 228         }
 229         xfree(cipher);
 230
 231         if (strstr(type, "dsa")) {
 232                 ktype = KEY_DSA;
 233         } else if (strstr(type, "rsa")) {
 234                 ktype = KEY_RSA;
 235         } else {
 236                 xfree(type);
 237                 return NULL;
 238         }
 239         key = key_new_private(ktype);
 240         xfree(type);
 241
 242         switch (key->type) {
 243         case KEY_DSA:
 244                 buffer_get_bignum_bits(&b, key->dsa->p);
 245                 buffer_get_bignum_bits(&b, key->dsa->g);
 246                 buffer_get_bignum_bits(&b, key->dsa->q);
 247                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 248                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 249                 break;
 250         case KEY_RSA:
 251                 e  = buffer_get_char(&b);
 252                 debug("e %lx", e);
 253                 if (e < 30) {
 254                         e <<= 8;
 255                         e += buffer_get_char(&b);
 256                         debug("e %lx", e);
 257                         e <<= 8;
 258                         e += buffer_get_char(&b);
 259                         debug("e %lx", e);
 260                 }
 261                 if (!BN_set_word(key->rsa->e, e)) {
 262                         buffer_free(&b);
 263                         key_free(key);
 264                         return NULL;
 265                 }
 266                 buffer_get_bignum_bits(&b, key->rsa->d);
 267                 buffer_get_bignum_bits(&b, key->rsa->n);
 268                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 269                 buffer_get_bignum_bits(&b, key->rsa->q);
 270                 buffer_get_bignum_bits(&b, key->rsa->p);
 271                 rsa_generate_additional_parameters(key->rsa);
 272                 break;
 273         }
 274         rlen = buffer_len(&b);
 275         if (rlen != 0)
 276                 error("do_convert_private_ssh2_from_blob: "
 277                     "remaining bytes in key blob %d", rlen);
 278         buffer_free(&b);
 279
 280         /* try the key */
 281         key_sign(key, &sig, &slen, data, sizeof(data));
 282         key_verify(key, sig, slen, data, sizeof(data));
 283         xfree(sig);
 284         return key;
 285 }
 286
 287 static void
 288 do_convert_from_ssh2(struct passwd *pw)
 289 {
 290         Key *k;
 291         int blen;
 292         u_int len;
 293         char line[1024], *p;
 294         u_char blob[8096];
 295         char encoded[8096];
 296         struct stat st;
 297         int escaped = 0, private = 0, ok;
 298         FILE *fp;
 299
 300         if (!have_identity)
 301                 ask_filename(pw, "Enter file in which the key is");
 302         if (stat(identity_file, &st) < 0) {
 303                 perror(identity_file);
 304                 exit(1);
 305         }
 306         fp = fopen(identity_file, "r");
 307         if (fp == NULL) {
 308                 perror(identity_file);
 309                 exit(1);
 310         }
 311         encoded[0] = '\0';
 312         while (fgets(line, sizeof(line), fp)) {
 313                 if (!(p = strchr(line, '\n'))) {
 314                         fprintf(stderr, "input line too long.\n");
 315                         exit(1);
 316                 }
 317                 if (p > line && p[-1] == '\\')
 318                         escaped++;
 319                 if (strncmp(line, "----", 4) == 0 ||
 320                     strstr(line, ": ") != NULL) {
 321                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 322                                 private = 1;
 323                         if (strstr(line, " END ") != NULL) {
 324                                 break;
 325                         }
 326                         /* fprintf(stderr, "ignore: %s", line); */
 327                         continue;
 328                 }
 329                 if (escaped) {
 330                         escaped--;
 331                         /* fprintf(stderr, "escaped: %s", line); */
 332                         continue;
 333                 }
 334                 *p = '\0';
 335                 strlcat(encoded, line, sizeof(encoded));
 336         }
 337         len = strlen(encoded);
 338         if (((len % 4) == 3) &&
 339             (encoded[len-1] == '=') &&
 340             (encoded[len-2] == '=') &&
 341             (encoded[len-3] == '='))
 342                 encoded[len-3] = '\0';
 343         blen = uudecode(encoded, blob, sizeof(blob));
 344         if (blen < 0) {
 345                 fprintf(stderr, "uudecode failed.\n");
 346                 exit(1);
 347         }
 348         k = private ?
 349             do_convert_private_ssh2_from_blob(blob, blen) :
 350             key_from_blob(blob, blen);
 351         if (k == NULL) {
 352                 fprintf(stderr, "decode blob failed.\n");
 353                 exit(1);
 354         }
 355         ok = private ?
 356             (k->type == KEY_DSA ?
 357                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 358                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 359             key_write(k, stdout);
 360         if (!ok) {
 361                 fprintf(stderr, "key write failed");
 362                 exit(1);
 363         }
 364         key_free(k);
 365         if (!private)
 366                 fprintf(stdout, "\n");
 367         fclose(fp);
 368         exit(0);
 369 }
 370
 371 static void
 372 do_print_public(struct passwd *pw)
 373 {
 374         Key *prv;
 375         struct stat st;
 376
 377         if (!have_identity)
 378                 ask_filename(pw, "Enter file in which the key is");
 379         if (stat(identity_file, &st) < 0) {
 380                 perror(identity_file);
 381                 exit(1);
 382         }
 383         prv = load_identity(identity_file);
 384         if (prv == NULL) {
 385                 fprintf(stderr, "load failed\n");
 386                 exit(1);
 387         }
 388         if (!key_write(prv, stdout))
 389                 fprintf(stderr, "key_write failed");
 390         key_free(prv);
 391         fprintf(stdout, "\n");
 392         exit(0);
 393 }
 394
 395 #ifdef SMARTCARD
 396 static void
 397 do_upload(struct passwd *pw, const char *sc_reader_id)
 398 {
 399         Key *prv = NULL;
 400         struct stat st;
 401         int ret;
 402
 403         if (!have_identity)
 404                 ask_filename(pw, "Enter file in which the key is");
 405         if (stat(identity_file, &st) < 0) {
 406                 perror(identity_file);
 407                 exit(1);
 408         }
 409         prv = load_identity(identity_file);
 410         if (prv == NULL) {
 411                 error("load failed");
 412                 exit(1);
 413         }
 414         ret = sc_put_key(prv, sc_reader_id);
 415         key_free(prv);
 416         if (ret < 0)
 417                 exit(1);
 418         logit("loading key done");
 419         exit(0);
 420 }
 421
 422 static void
 423 do_download(struct passwd *pw, const char *sc_reader_id)
 424 {
 425         Key **keys = NULL;
 426         int i;
 427
 428         keys = sc_get_keys(sc_reader_id, NULL);
 429         if (keys == NULL)
 430                 fatal("cannot read public key from smartcard");
 431         for (i = 0; keys[i]; i++) {
 432                 key_write(keys[i], stdout);
 433                 key_free(keys[i]);
 434                 fprintf(stdout, "\n");
 435         }
 436         xfree(keys);
 437         exit(0);
 438 }
 439 #endif /* SMARTCARD */
 440
 441 static void
 442 do_fingerprint(struct passwd *pw)
 443 {
 444         FILE *f;
 445         Key *public;
 446         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 447         int i, skip = 0, num = 1, invalid = 1;
 448         enum fp_rep rep;
 449         enum fp_type fptype;
 450         struct stat st;
 451
 452         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 453         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 454
 455         if (!have_identity)
 456                 ask_filename(pw, "Enter file in which the key is");
 457         if (stat(identity_file, &st) < 0) {
 458                 perror(identity_file);
 459                 exit(1);
 460         }
 461         public = key_load_public(identity_file, &comment);
 462         if (public != NULL) {
 463                 fp = key_fingerprint(public, fptype, rep);
 464                 printf("%u %s %s\n", key_size(public), fp, comment);
 465                 key_free(public);
 466                 xfree(comment);
 467                 xfree(fp);
 468                 exit(0);
 469         }
 470         if (comment)
 471                 xfree(comment);
 472
 473         f = fopen(identity_file, "r");
 474         if (f != NULL) {
 475                 while (fgets(line, sizeof(line), f)) {
 476                         i = strlen(line) - 1;
 477                         if (line[i] != '\n') {
 478                                 error("line %d too long: %.40s...", num, line);
 479                                 skip = 1;
 480                                 continue;
 481                         }
 482                         num++;
 483                         if (skip) {
 484                                 skip = 0;
 485                                 continue;
 486                         }
 487                         line[i] = '\0';
 488
 489                         /* Skip leading whitespace, empty and comment lines. */
 490                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 491                                 ;
 492                         if (!*cp || *cp == '\n' || *cp == '#')
 493                                 continue ;
 494                         i = strtol(cp, &ep, 10);
 495                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 496                                 int quoted = 0;
 497                                 comment = cp;
 498                                 for (; *cp && (quoted || (*cp != ' ' &&
 499                                     *cp != '\t')); cp++) {
 500                                         if (*cp == '\\' && cp[1] == '"')
 501                                                 cp++;   /* Skip both */
 502                                         else if (*cp == '"')
 503                                                 quoted = !quoted;
 504                                 }
 505                                 if (!*cp)
 506                                         continue;
 507                                 *cp++ = '\0';
 508                         }
 509                         ep = cp;
 510                         public = key_new(KEY_RSA1);
 511                         if (key_read(public, &cp) != 1) {
 512                                 cp = ep;
 513                                 key_free(public);
 514                                 public = key_new(KEY_UNSPEC);
 515                                 if (key_read(public, &cp) != 1) {
 516                                         key_free(public);
 517                                         continue;
 518                                 }
 519                         }
 520                         comment = *cp ? cp : comment;
 521                         fp = key_fingerprint(public, fptype, rep);
 522                         printf("%u %s %s\n", key_size(public), fp,
 523                             comment ? comment : "no comment");
 524                         xfree(fp);
 525                         key_free(public);
 526                         invalid = 0;
 527                 }
 528                 fclose(f);
 529         }
 530         if (invalid) {
 531                 printf("%s is not a public key file.\n", identity_file);
 532                 exit(1);
 533         }
 534         exit(0);
 535 }
 536
 537 /*
 538  * Perform changing a passphrase.  The argument is the passwd structure
 539  * for the current user.
 540  */
 541 static void
 542 do_change_passphrase(struct passwd *pw)
 543 {
 544         char *comment;
 545         char *old_passphrase, *passphrase1, *passphrase2;
 546         struct stat st;
 547         Key *private;
 548
 549         if (!have_identity)
 550                 ask_filename(pw, "Enter file in which the key is");
 551         if (stat(identity_file, &st) < 0) {
 552                 perror(identity_file);
 553                 exit(1);
 554         }
 555         /* Try to load the file with empty passphrase. */
 556         private = key_load_private(identity_file, "", &comment);
 557         if (private == NULL) {
 558                 if (identity_passphrase)
 559                         old_passphrase = xstrdup(identity_passphrase);
 560                 else
 561                         old_passphrase =
 562                             read_passphrase("Enter old passphrase: ",
 563                             RP_ALLOW_STDIN);
 564                 private = key_load_private(identity_file, old_passphrase,
 565                     &comment);
 566                 memset(old_passphrase, 0, strlen(old_passphrase));
 567                 xfree(old_passphrase);
 568                 if (private == NULL) {
 569                         printf("Bad passphrase.\n");
 570                         exit(1);
 571                 }
 572         }
 573         printf("Key has comment '%s'\n", comment);
 574
 575         /* Ask the new passphrase (twice). */
 576         if (identity_new_passphrase) {
 577                 passphrase1 = xstrdup(identity_new_passphrase);
 578                 passphrase2 = NULL;
 579         } else {
 580                 passphrase1 =
 581                         read_passphrase("Enter new passphrase (empty for no "
 582                             "passphrase): ", RP_ALLOW_STDIN);
 583                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 584                     RP_ALLOW_STDIN);
 585
 586                 /* Verify that they are the same. */
 587                 if (strcmp(passphrase1, passphrase2) != 0) {
 588                         memset(passphrase1, 0, strlen(passphrase1));
 589                         memset(passphrase2, 0, strlen(passphrase2));
 590                         xfree(passphrase1);
 591                         xfree(passphrase2);
 592                         printf("Pass phrases do not match.  Try again.\n");
 593                         exit(1);
 594                 }
 595                 /* Destroy the other copy. */
 596                 memset(passphrase2, 0, strlen(passphrase2));
 597                 xfree(passphrase2);
 598         }
 599
 600         /* Save the file using the new passphrase. */
 601         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 602                 printf("Saving the key failed: %s.\n", identity_file);
 603                 memset(passphrase1, 0, strlen(passphrase1));
 604                 xfree(passphrase1);
 605                 key_free(private);
 606                 xfree(comment);
 607                 exit(1);
 608         }
 609         /* Destroy the passphrase and the copy of the key in memory. */
 610         memset(passphrase1, 0, strlen(passphrase1));
 611         xfree(passphrase1);
 612         key_free(private);               /* Destroys contents */
 613         xfree(comment);
 614
 615         printf("Your identification has been saved with the new passphrase.\n");
 616         exit(0);
 617 }
 618
 619 /*
 620  * Change the comment of a private key file.
 621  */
 622 static void
 623 do_change_comment(struct passwd *pw)
 624 {
 625         char new_comment[1024], *comment, *passphrase;
 626         Key *private;
 627         Key *public;
 628         struct stat st;
 629         FILE *f;
 630         int fd;
 631
 632         if (!have_identity)
 633                 ask_filename(pw, "Enter file in which the key is");
 634         if (stat(identity_file, &st) < 0) {
 635                 perror(identity_file);
 636                 exit(1);
 637         }
 638         private = key_load_private(identity_file, "", &comment);
 639         if (private == NULL) {
 640                 if (identity_passphrase)
 641                         passphrase = xstrdup(identity_passphrase);
 642                 else if (identity_new_passphrase)
 643                         passphrase = xstrdup(identity_new_passphrase);
 644                 else
 645                         passphrase = read_passphrase("Enter passphrase: ",
 646                             RP_ALLOW_STDIN);
 647                 /* Try to load using the passphrase. */
 648                 private = key_load_private(identity_file, passphrase, &comment);
 649                 if (private == NULL) {
 650                         memset(passphrase, 0, strlen(passphrase));
 651                         xfree(passphrase);
 652                         printf("Bad passphrase.\n");
 653                         exit(1);
 654                 }
 655         } else {
 656                 passphrase = xstrdup("");
 657         }
 658         if (private->type != KEY_RSA1) {
 659                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 660                 key_free(private);
 661                 exit(1);
 662         }
 663         printf("Key now has comment '%s'\n", comment);
 664
 665         if (identity_comment) {
 666                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 667         } else {
 668                 printf("Enter new comment: ");
 669                 fflush(stdout);
 670                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 671                         memset(passphrase, 0, strlen(passphrase));
 672                         key_free(private);
 673                         exit(1);
 674                 }
 675                 if (strchr(new_comment, '\n'))
 676                         *strchr(new_comment, '\n') = 0;
 677         }
 678
 679         /* Save the file using the new passphrase. */
 680         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 681                 printf("Saving the key failed: %s.\n", identity_file);
 682                 memset(passphrase, 0, strlen(passphrase));
 683                 xfree(passphrase);
 684                 key_free(private);
 685                 xfree(comment);
 686                 exit(1);
 687         }
 688         memset(passphrase, 0, strlen(passphrase));
 689         xfree(passphrase);
 690         public = key_from_private(private);
 691         key_free(private);
 692
 693         strlcat(identity_file, ".pub", sizeof(identity_file));
 694         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 695         if (fd == -1) {
 696                 printf("Could not save your public key in %s\n", identity_file);
 697                 exit(1);
 698         }
 699         f = fdopen(fd, "w");
 700         if (f == NULL) {
 701                 printf("fdopen %s failed", identity_file);
 702                 exit(1);
 703         }
 704         if (!key_write(public, f))
 705                 fprintf(stderr, "write key failed");
 706         key_free(public);
 707         fprintf(f, " %s\n", new_comment);
 708         fclose(f);
 709
 710         xfree(comment);
 711
 712         printf("The comment in your key file has been changed.\n");
 713         exit(0);
 714 }
 715
 716 static void
 717 usage(void)
 718 {
 719         fprintf(stderr, "Usage: %s [options]\n", __progname);
 720         fprintf(stderr, "Options:\n");
 721         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 722         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 723         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 724         fprintf(stderr, "  -f filename Filename of the key file.\n");
 725         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 726         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 727         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 728         fprintf(stderr, "  -q          Quiet.\n");
 729         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 730         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 731         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 732         fprintf(stderr, "  -C comment  Provide new comment.\n");
 733         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 734         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 735 #ifdef SMARTCARD
 736         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 737         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 738 #endif /* SMARTCARD */
 739
 740         exit(1);
 741 }
 742
 743 /*
 744  * Main program for key management.
 745  */
 746 int
 747 main(int ac, char **av)
 748 {
 749         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 750         char *reader_id = NULL;
 751         Key *private, *public;
 752         struct passwd *pw;
 753         struct stat st;
 754         int opt, type, fd, download = 0;
 755         FILE *f;
 756
 757         extern int optind;
 758         extern char *optarg;
 759
 760         __progname = get_progname(av[0]);
 761
 762         SSLeay_add_all_algorithms();
 763         init_rng();
 764         seed_rng();
 765
 766         /* we need this for the home * directory.  */
 767         pw = getpwuid(getuid());
 768         if (!pw) {
 769                 printf("You don't exist, go away!\n");
 770                 exit(1);
 771         }
 772         if (gethostname(hostname, sizeof(hostname)) < 0) {
 773                 perror("gethostname");
 774                 exit(1);
 775         }
 776
 777         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
 778                 switch (opt) {
 779                 case 'b':
 780                         bits = atoi(optarg);
 781                         if (bits < 512 || bits > 32768) {
 782                                 printf("Bits has bad value.\n");
 783                                 exit(1);
 784                         }
 785                         break;
 786                 case 'l':
 787                         print_fingerprint = 1;
 788                         break;
 789                 case 'B':
 790                         print_bubblebabble = 1;
 791                         break;
 792                 case 'p':
 793                         change_passphrase = 1;
 794                         break;
 795                 case 'c':
 796                         change_comment = 1;
 797                         break;
 798                 case 'f':
 799                         strlcpy(identity_file, optarg, sizeof(identity_file));
 800                         have_identity = 1;
 801                         break;
 802                 case 'P':
 803                         identity_passphrase = optarg;
 804                         break;
 805                 case 'N':
 806                         identity_new_passphrase = optarg;
 807                         break;
 808                 case 'C':
 809                         identity_comment = optarg;
 810                         break;
 811                 case 'q':
 812                         quiet = 1;
 813                         break;
 814                 case 'R':
 815                         /* unused */
 816                         exit(0);
 817                         break;
 818                 case 'e':
 819                 case 'x':
 820                         /* export key */
 821                         convert_to_ssh2 = 1;
 822                         break;
 823                 case 'i':
 824                 case 'X':
 825                         /* import key */
 826                         convert_from_ssh2 = 1;
 827                         break;
 828                 case 'y':
 829                         print_public = 1;
 830                         break;
 831                 case 'd':
 832                         key_type_name = "dsa";
 833                         break;
 834                 case 't':
 835                         key_type_name = optarg;
 836                         break;
 837                 case 'D':
 838                         download = 1;
 839                 case 'U':
 840                         reader_id = optarg;
 841                         break;
 842                 case '?':
 843                 default:
 844                         usage();
 845                 }
 846         }
 847         if (optind < ac) {
 848                 printf("Too many arguments.\n");
 849                 usage();
 850         }
 851         if (change_passphrase && change_comment) {
 852                 printf("Can only have one of -p and -c.\n");
 853                 usage();
 854         }
 855         if (print_fingerprint || print_bubblebabble)
 856                 do_fingerprint(pw);
 857         if (change_passphrase)
 858                 do_change_passphrase(pw);
 859         if (change_comment)
 860                 do_change_comment(pw);
 861         if (convert_to_ssh2)
 862                 do_convert_to_ssh2(pw);
 863         if (convert_from_ssh2)
 864                 do_convert_from_ssh2(pw);
 865         if (print_public)
 866                 do_print_public(pw);
 867         if (reader_id != NULL) {
 868 #ifdef SMARTCARD
 869                 if (download)
 870                         do_download(pw, reader_id);
 871                 else
 872                         do_upload(pw, reader_id);
 873 #else /* SMARTCARD */
 874                 fatal("no support for smartcards.");
 875 #endif /* SMARTCARD */
 876         }
 877
 878         arc4random_stir();
 879
 880         if (key_type_name == NULL) {
 881                 printf("You must specify a key type (-t).\n");
 882                 usage();
 883         }
 884         type = key_type_from_name(key_type_name);
 885         if (type == KEY_UNSPEC) {
 886                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 887                 exit(1);
 888         }
 889         if (!quiet)
 890                 printf("Generating public/private %s key pair.\n", key_type_name);
 891         private = key_generate(type, bits);
 892         if (private == NULL) {
 893                 fprintf(stderr, "key_generate failed");
 894                 exit(1);
 895         }
 896         public  = key_from_private(private);
 897
 898         if (!have_identity)
 899                 ask_filename(pw, "Enter file in which to save the key");
 900
 901         /* Create ~/.ssh directory if it doesn\'t already exist. */
 902         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 903         if (strstr(identity_file, dotsshdir) != NULL &&
 904             stat(dotsshdir, &st) < 0) {
 905                 if (mkdir(dotsshdir, 0700) < 0)
 906                         error("Could not create directory '%s'.", dotsshdir);
 907                 else if (!quiet)
 908                         printf("Created directory '%s'.\n", dotsshdir);
 909         }
 910         /* If the file already exists, ask the user to confirm. */
 911         if (stat(identity_file, &st) >= 0) {
 912                 char yesno[3];
 913                 printf("%s already exists.\n", identity_file);
 914                 printf("Overwrite (y/n)? ");
 915                 fflush(stdout);
 916                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 917                         exit(1);
 918                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 919                         exit(1);
 920         }
 921         /* Ask for a passphrase (twice). */
 922         if (identity_passphrase)
 923                 passphrase1 = xstrdup(identity_passphrase);
 924         else if (identity_new_passphrase)
 925                 passphrase1 = xstrdup(identity_new_passphrase);
 926         else {
 927 passphrase_again:
 928                 passphrase1 =
 929                         read_passphrase("Enter passphrase (empty for no "
 930                             "passphrase): ", RP_ALLOW_STDIN);
 931                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 932                     RP_ALLOW_STDIN);
 933                 if (strcmp(passphrase1, passphrase2) != 0) {
 934                         /*
 935                          * The passphrases do not match.  Clear them and
 936                          * retry.
 937                          */
 938                         memset(passphrase1, 0, strlen(passphrase1));
 939                         memset(passphrase2, 0, strlen(passphrase2));
 940                         xfree(passphrase1);
 941                         xfree(passphrase2);
 942                         printf("Passphrases do not match.  Try again.\n");
 943                         goto passphrase_again;
 944                 }
 945                 /* Clear the other copy of the passphrase. */
 946                 memset(passphrase2, 0, strlen(passphrase2));
 947                 xfree(passphrase2);
 948         }
 949
 950         if (identity_comment) {
 951                 strlcpy(comment, identity_comment, sizeof(comment));
 952         } else {
 953                 /* Create default commend field for the passphrase. */
 954                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 955         }
 956
 957         /* Save the key with the given passphrase and comment. */
 958         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 959                 printf("Saving the key failed: %s.\n", identity_file);
 960                 memset(passphrase1, 0, strlen(passphrase1));
 961                 xfree(passphrase1);
 962                 exit(1);
 963         }
 964         /* Clear the passphrase. */
 965         memset(passphrase1, 0, strlen(passphrase1));
 966         xfree(passphrase1);
 967
 968         /* Clear the private key and the random number generator. */
 969         key_free(private);
 970         arc4random_stir();
 971
 972         if (!quiet)
 973                 printf("Your identification has been saved in %s.\n", identity_file);
 974
 975         strlcat(identity_file, ".pub", sizeof(identity_file));
 976         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 977         if (fd == -1) {
 978                 printf("Could not save your public key in %s\n", identity_file);
 979                 exit(1);
 980         }
 981         f = fdopen(fd, "w");
 982         if (f == NULL) {
 983                 printf("fdopen %s failed", identity_file);
 984                 exit(1);
 985         }
 986         if (!key_write(public, f))
 987                 fprintf(stderr, "write key failed");
 988         fprintf(f, " %s\n", comment);
 989         fclose(f);
 990
 991         if (!quiet) {
 992                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 993                 printf("Your public key has been saved in %s.\n",
 994                     identity_file);
 995                 printf("The key fingerprint is:\n");
 996                 printf("%s %s\n", fp, comment);
 997                 xfree(fp);
 998         }
 999
1000         key_free(public);
1001         exit(0);
1002 }