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 1.104 2003/05/11 16:56:48 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 #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 (k->type == KEY_RSA1) {
 167                 fprintf(stderr, "version 1 keys are not supported\n");
 168                 exit(1);
 169         }
 170         if (key_to_blob(k, &blob, &len) <= 0) {
 171                 fprintf(stderr, "key_to_blob failed\n");
 172                 exit(1);
 173         }
 174         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 175         fprintf(stdout,
 176             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 177             key_size(k), key_type(k),
 178             pw->pw_name, hostname);
 179         dump_base64(stdout, blob, len);
 180         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 181         key_free(k);
 182         xfree(blob);
 183         exit(0);
 184 }
 185
 186 static void
 187 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 188 {
 189         int bits = buffer_get_int(b);
 190         int bytes = (bits + 7) / 8;
 191
 192         if (buffer_len(b) < bytes)
 193                 fatal("buffer_get_bignum_bits: input buffer too small: "
 194                     "need %d have %d", bytes, buffer_len(b));
 195         BN_bin2bn(buffer_ptr(b), bytes, value);
 196         buffer_consume(b, bytes);
 197 }
 198
 199 static Key *
 200 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 201 {
 202         Buffer b;
 203         Key *key = NULL;
 204         char *type, *cipher;
 205         u_char *sig, data[] = "abcde12345";
 206         int magic, rlen, ktype, i1, i2, i3, i4;
 207         u_int slen;
 208         u_long e;
 209
 210         buffer_init(&b);
 211         buffer_append(&b, blob, blen);
 212
 213         magic  = buffer_get_int(&b);
 214         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 215                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 216                 buffer_free(&b);
 217                 return NULL;
 218         }
 219         i1 = buffer_get_int(&b);
 220         type   = buffer_get_string(&b, NULL);
 221         cipher = buffer_get_string(&b, NULL);
 222         i2 = buffer_get_int(&b);
 223         i3 = buffer_get_int(&b);
 224         i4 = buffer_get_int(&b);
 225         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 226         if (strcmp(cipher, "none") != 0) {
 227                 error("unsupported cipher %s", cipher);
 228                 xfree(cipher);
 229                 buffer_free(&b);
 230                 xfree(type);
 231                 return NULL;
 232         }
 233         xfree(cipher);
 234
 235         if (strstr(type, "dsa")) {
 236                 ktype = KEY_DSA;
 237         } else if (strstr(type, "rsa")) {
 238                 ktype = KEY_RSA;
 239         } else {
 240                 xfree(type);
 241                 return NULL;
 242         }
 243         key = key_new_private(ktype);
 244         xfree(type);
 245
 246         switch (key->type) {
 247         case KEY_DSA:
 248                 buffer_get_bignum_bits(&b, key->dsa->p);
 249                 buffer_get_bignum_bits(&b, key->dsa->g);
 250                 buffer_get_bignum_bits(&b, key->dsa->q);
 251                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 252                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 253                 break;
 254         case KEY_RSA:
 255                 e  = buffer_get_char(&b);
 256                 debug("e %lx", e);
 257                 if (e < 30) {
 258                         e <<= 8;
 259                         e += buffer_get_char(&b);
 260                         debug("e %lx", e);
 261                         e <<= 8;
 262                         e += buffer_get_char(&b);
 263                         debug("e %lx", e);
 264                 }
 265                 if (!BN_set_word(key->rsa->e, e)) {
 266                         buffer_free(&b);
 267                         key_free(key);
 268                         return NULL;
 269                 }
 270                 buffer_get_bignum_bits(&b, key->rsa->d);
 271                 buffer_get_bignum_bits(&b, key->rsa->n);
 272                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 273                 buffer_get_bignum_bits(&b, key->rsa->q);
 274                 buffer_get_bignum_bits(&b, key->rsa->p);
 275                 rsa_generate_additional_parameters(key->rsa);
 276                 break;
 277         }
 278         rlen = buffer_len(&b);
 279         if (rlen != 0)
 280                 error("do_convert_private_ssh2_from_blob: "
 281                     "remaining bytes in key blob %d", rlen);
 282         buffer_free(&b);
 283
 284         /* try the key */
 285         key_sign(key, &sig, &slen, data, sizeof(data));
 286         key_verify(key, sig, slen, data, sizeof(data));
 287         xfree(sig);
 288         return key;
 289 }
 290
 291 static void
 292 do_convert_from_ssh2(struct passwd *pw)
 293 {
 294         Key *k;
 295         int blen;
 296         u_int len;
 297         char line[1024], *p;
 298         u_char blob[8096];
 299         char encoded[8096];
 300         struct stat st;
 301         int escaped = 0, private = 0, ok;
 302         FILE *fp;
 303
 304         if (!have_identity)
 305                 ask_filename(pw, "Enter file in which the key is");
 306         if (stat(identity_file, &st) < 0) {
 307                 perror(identity_file);
 308                 exit(1);
 309         }
 310         fp = fopen(identity_file, "r");
 311         if (fp == NULL) {
 312                 perror(identity_file);
 313                 exit(1);
 314         }
 315         encoded[0] = '\0';
 316         while (fgets(line, sizeof(line), fp)) {
 317                 if (!(p = strchr(line, '\n'))) {
 318                         fprintf(stderr, "input line too long.\n");
 319                         exit(1);
 320                 }
 321                 if (p > line && p[-1] == '\\')
 322                         escaped++;
 323                 if (strncmp(line, "----", 4) == 0 ||
 324                     strstr(line, ": ") != NULL) {
 325                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 326                                 private = 1;
 327                         if (strstr(line, " END ") != NULL) {
 328                                 break;
 329                         }
 330                         /* fprintf(stderr, "ignore: %s", line); */
 331                         continue;
 332                 }
 333                 if (escaped) {
 334                         escaped--;
 335                         /* fprintf(stderr, "escaped: %s", line); */
 336                         continue;
 337                 }
 338                 *p = '\0';
 339                 strlcat(encoded, line, sizeof(encoded));
 340         }
 341         len = strlen(encoded);
 342         if (((len % 4) == 3) &&
 343             (encoded[len-1] == '=') &&
 344             (encoded[len-2] == '=') &&
 345             (encoded[len-3] == '='))
 346                 encoded[len-3] = '\0';
 347         blen = uudecode(encoded, blob, sizeof(blob));
 348         if (blen < 0) {
 349                 fprintf(stderr, "uudecode failed.\n");
 350                 exit(1);
 351         }
 352         k = private ?
 353             do_convert_private_ssh2_from_blob(blob, blen) :
 354             key_from_blob(blob, blen);
 355         if (k == NULL) {
 356                 fprintf(stderr, "decode blob failed.\n");
 357                 exit(1);
 358         }
 359         ok = private ?
 360             (k->type == KEY_DSA ?
 361                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 362                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 363             key_write(k, stdout);
 364         if (!ok) {
 365                 fprintf(stderr, "key write failed");
 366                 exit(1);
 367         }
 368         key_free(k);
 369         if (!private)
 370                 fprintf(stdout, "\n");
 371         fclose(fp);
 372         exit(0);
 373 }
 374
 375 static void
 376 do_print_public(struct passwd *pw)
 377 {
 378         Key *prv;
 379         struct stat st;
 380
 381         if (!have_identity)
 382                 ask_filename(pw, "Enter file in which the key is");
 383         if (stat(identity_file, &st) < 0) {
 384                 perror(identity_file);
 385                 exit(1);
 386         }
 387         prv = load_identity(identity_file);
 388         if (prv == NULL) {
 389                 fprintf(stderr, "load failed\n");
 390                 exit(1);
 391         }
 392         if (!key_write(prv, stdout))
 393                 fprintf(stderr, "key_write failed");
 394         key_free(prv);
 395         fprintf(stdout, "\n");
 396         exit(0);
 397 }
 398
 399 #ifdef SMARTCARD
 400 static void
 401 do_upload(struct passwd *pw, const char *sc_reader_id)
 402 {
 403         Key *prv = NULL;
 404         struct stat st;
 405         int ret;
 406
 407         if (!have_identity)
 408                 ask_filename(pw, "Enter file in which the key is");
 409         if (stat(identity_file, &st) < 0) {
 410                 perror(identity_file);
 411                 exit(1);
 412         }
 413         prv = load_identity(identity_file);
 414         if (prv == NULL) {
 415                 error("load failed");
 416                 exit(1);
 417         }
 418         ret = sc_put_key(prv, sc_reader_id);
 419         key_free(prv);
 420         if (ret < 0)
 421                 exit(1);
 422         logit("loading key done");
 423         exit(0);
 424 }
 425
 426 static void
 427 do_download(struct passwd *pw, const char *sc_reader_id)
 428 {
 429         Key **keys = NULL;
 430         int i;
 431
 432         keys = sc_get_keys(sc_reader_id, NULL);
 433         if (keys == NULL)
 434                 fatal("cannot read public key from smartcard");
 435         for (i = 0; keys[i]; i++) {
 436                 key_write(keys[i], stdout);
 437                 key_free(keys[i]);
 438                 fprintf(stdout, "\n");
 439         }
 440         xfree(keys);
 441         exit(0);
 442 }
 443 #endif /* SMARTCARD */
 444
 445 static void
 446 do_fingerprint(struct passwd *pw)
 447 {
 448         FILE *f;
 449         Key *public;
 450         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 451         int i, skip = 0, num = 1, invalid = 1;
 452         enum fp_rep rep;
 453         enum fp_type fptype;
 454         struct stat st;
 455
 456         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 457         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 458
 459         if (!have_identity)
 460                 ask_filename(pw, "Enter file in which the key is");
 461         if (stat(identity_file, &st) < 0) {
 462                 perror(identity_file);
 463                 exit(1);
 464         }
 465         public = key_load_public(identity_file, &comment);
 466         if (public != NULL) {
 467                 fp = key_fingerprint(public, fptype, rep);
 468                 printf("%u %s %s\n", key_size(public), fp, comment);
 469                 key_free(public);
 470                 xfree(comment);
 471                 xfree(fp);
 472                 exit(0);
 473         }
 474         if (comment)
 475                 xfree(comment);
 476
 477         f = fopen(identity_file, "r");
 478         if (f != NULL) {
 479                 while (fgets(line, sizeof(line), f)) {
 480                         i = strlen(line) - 1;
 481                         if (line[i] != '\n') {
 482                                 error("line %d too long: %.40s...", num, line);
 483                                 skip = 1;
 484                                 continue;
 485                         }
 486                         num++;
 487                         if (skip) {
 488                                 skip = 0;
 489                                 continue;
 490                         }
 491                         line[i] = '\0';
 492
 493                         /* Skip leading whitespace, empty and comment lines. */
 494                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 495                                 ;
 496                         if (!*cp || *cp == '\n' || *cp == '#')
 497                                 continue ;
 498                         i = strtol(cp, &ep, 10);
 499                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 500                                 int quoted = 0;
 501                                 comment = cp;
 502                                 for (; *cp && (quoted || (*cp != ' ' &&
 503                                     *cp != '\t')); cp++) {
 504                                         if (*cp == '\\' && cp[1] == '"')
 505                                                 cp++;   /* Skip both */
 506                                         else if (*cp == '"')
 507                                                 quoted = !quoted;
 508                                 }
 509                                 if (!*cp)
 510                                         continue;
 511                                 *cp++ = '\0';
 512                         }
 513                         ep = cp;
 514                         public = key_new(KEY_RSA1);
 515                         if (key_read(public, &cp) != 1) {
 516                                 cp = ep;
 517                                 key_free(public);
 518                                 public = key_new(KEY_UNSPEC);
 519                                 if (key_read(public, &cp) != 1) {
 520                                         key_free(public);
 521                                         continue;
 522                                 }
 523                         }
 524                         comment = *cp ? cp : comment;
 525                         fp = key_fingerprint(public, fptype, rep);
 526                         printf("%u %s %s\n", key_size(public), fp,
 527                             comment ? comment : "no comment");
 528                         xfree(fp);
 529                         key_free(public);
 530                         invalid = 0;
 531                 }
 532                 fclose(f);
 533         }
 534         if (invalid) {
 535                 printf("%s is not a public key file.\n", identity_file);
 536                 exit(1);
 537         }
 538         exit(0);
 539 }
 540
 541 /*
 542  * Perform changing a passphrase.  The argument is the passwd structure
 543  * for the current user.
 544  */
 545 static void
 546 do_change_passphrase(struct passwd *pw)
 547 {
 548         char *comment;
 549         char *old_passphrase, *passphrase1, *passphrase2;
 550         struct stat st;
 551         Key *private;
 552
 553         if (!have_identity)
 554                 ask_filename(pw, "Enter file in which the key is");
 555         if (stat(identity_file, &st) < 0) {
 556                 perror(identity_file);
 557                 exit(1);
 558         }
 559         /* Try to load the file with empty passphrase. */
 560         private = key_load_private(identity_file, "", &comment);
 561         if (private == NULL) {
 562                 if (identity_passphrase)
 563                         old_passphrase = xstrdup(identity_passphrase);
 564                 else
 565                         old_passphrase =
 566                             read_passphrase("Enter old passphrase: ",
 567                             RP_ALLOW_STDIN);
 568                 private = key_load_private(identity_file, old_passphrase,
 569                     &comment);
 570                 memset(old_passphrase, 0, strlen(old_passphrase));
 571                 xfree(old_passphrase);
 572                 if (private == NULL) {
 573                         printf("Bad passphrase.\n");
 574                         exit(1);
 575                 }
 576         }
 577         printf("Key has comment '%s'\n", comment);
 578
 579         /* Ask the new passphrase (twice). */
 580         if (identity_new_passphrase) {
 581                 passphrase1 = xstrdup(identity_new_passphrase);
 582                 passphrase2 = NULL;
 583         } else {
 584                 passphrase1 =
 585                         read_passphrase("Enter new passphrase (empty for no "
 586                             "passphrase): ", RP_ALLOW_STDIN);
 587                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 588                     RP_ALLOW_STDIN);
 589
 590                 /* Verify that they are the same. */
 591                 if (strcmp(passphrase1, passphrase2) != 0) {
 592                         memset(passphrase1, 0, strlen(passphrase1));
 593                         memset(passphrase2, 0, strlen(passphrase2));
 594                         xfree(passphrase1);
 595                         xfree(passphrase2);
 596                         printf("Pass phrases do not match.  Try again.\n");
 597                         exit(1);
 598                 }
 599                 /* Destroy the other copy. */
 600                 memset(passphrase2, 0, strlen(passphrase2));
 601                 xfree(passphrase2);
 602         }
 603
 604         /* Save the file using the new passphrase. */
 605         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 606                 printf("Saving the key failed: %s.\n", identity_file);
 607                 memset(passphrase1, 0, strlen(passphrase1));
 608                 xfree(passphrase1);
 609                 key_free(private);
 610                 xfree(comment);
 611                 exit(1);
 612         }
 613         /* Destroy the passphrase and the copy of the key in memory. */
 614         memset(passphrase1, 0, strlen(passphrase1));
 615         xfree(passphrase1);
 616         key_free(private);               /* Destroys contents */
 617         xfree(comment);
 618
 619         printf("Your identification has been saved with the new passphrase.\n");
 620         exit(0);
 621 }
 622
 623 /*
 624  * Change the comment of a private key file.
 625  */
 626 static void
 627 do_change_comment(struct passwd *pw)
 628 {
 629         char new_comment[1024], *comment, *passphrase;
 630         Key *private;
 631         Key *public;
 632         struct stat st;
 633         FILE *f;
 634         int fd;
 635
 636         if (!have_identity)
 637                 ask_filename(pw, "Enter file in which the key is");
 638         if (stat(identity_file, &st) < 0) {
 639                 perror(identity_file);
 640                 exit(1);
 641         }
 642         private = key_load_private(identity_file, "", &comment);
 643         if (private == NULL) {
 644                 if (identity_passphrase)
 645                         passphrase = xstrdup(identity_passphrase);
 646                 else if (identity_new_passphrase)
 647                         passphrase = xstrdup(identity_new_passphrase);
 648                 else
 649                         passphrase = read_passphrase("Enter passphrase: ",
 650                             RP_ALLOW_STDIN);
 651                 /* Try to load using the passphrase. */
 652                 private = key_load_private(identity_file, passphrase, &comment);
 653                 if (private == NULL) {
 654                         memset(passphrase, 0, strlen(passphrase));
 655                         xfree(passphrase);
 656                         printf("Bad passphrase.\n");
 657                         exit(1);
 658                 }
 659         } else {
 660                 passphrase = xstrdup("");
 661         }
 662         if (private->type != KEY_RSA1) {
 663                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 664                 key_free(private);
 665                 exit(1);
 666         }
 667         printf("Key now has comment '%s'\n", comment);
 668
 669         if (identity_comment) {
 670                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 671         } else {
 672                 printf("Enter new comment: ");
 673                 fflush(stdout);
 674                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 675                         memset(passphrase, 0, strlen(passphrase));
 676                         key_free(private);
 677                         exit(1);
 678                 }
 679                 if (strchr(new_comment, '\n'))
 680                         *strchr(new_comment, '\n') = 0;
 681         }
 682
 683         /* Save the file using the new passphrase. */
 684         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 685                 printf("Saving the key failed: %s.\n", identity_file);
 686                 memset(passphrase, 0, strlen(passphrase));
 687                 xfree(passphrase);
 688                 key_free(private);
 689                 xfree(comment);
 690                 exit(1);
 691         }
 692         memset(passphrase, 0, strlen(passphrase));
 693         xfree(passphrase);
 694         public = key_from_private(private);
 695         key_free(private);
 696
 697         strlcat(identity_file, ".pub", sizeof(identity_file));
 698         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 699         if (fd == -1) {
 700                 printf("Could not save your public key in %s\n", identity_file);
 701                 exit(1);
 702         }
 703         f = fdopen(fd, "w");
 704         if (f == NULL) {
 705                 printf("fdopen %s failed", identity_file);
 706                 exit(1);
 707         }
 708         if (!key_write(public, f))
 709                 fprintf(stderr, "write key failed");
 710         key_free(public);
 711         fprintf(f, " %s\n", new_comment);
 712         fclose(f);
 713
 714         xfree(comment);
 715
 716         printf("The comment in your key file has been changed.\n");
 717         exit(0);
 718 }
 719
 720 static void
 721 usage(void)
 722 {
 723         fprintf(stderr, "Usage: %s [options]\n", __progname);
 724         fprintf(stderr, "Options:\n");
 725         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 726         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 727         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 728         fprintf(stderr, "  -f filename Filename of the key file.\n");
 729         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 730         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 731         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 732         fprintf(stderr, "  -q          Quiet.\n");
 733         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 734         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 735         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 736         fprintf(stderr, "  -C comment  Provide new comment.\n");
 737         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 738         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 739 #ifdef SMARTCARD
 740         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 741         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 742 #endif /* SMARTCARD */
 743
 744         exit(1);
 745 }
 746
 747 /*
 748  * Main program for key management.
 749  */
 750 int
 751 main(int ac, char **av)
 752 {
 753         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 754         char *reader_id = NULL;
 755         Key *private, *public;
 756         struct passwd *pw;
 757         struct stat st;
 758         int opt, type, fd, download = 0;
 759         FILE *f;
 760
 761         extern int optind;
 762         extern char *optarg;
 763
 764         __progname = get_progname(av[0]);
 765
 766         SSLeay_add_all_algorithms();
 767         init_rng();
 768         seed_rng();
 769
 770         /* we need this for the home * directory.  */
 771         pw = getpwuid(getuid());
 772         if (!pw) {
 773                 printf("You don't exist, go away!\n");
 774                 exit(1);
 775         }
 776         if (gethostname(hostname, sizeof(hostname)) < 0) {
 777                 perror("gethostname");
 778                 exit(1);
 779         }
 780
 781         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
 782                 switch (opt) {
 783                 case 'b':
 784                         bits = atoi(optarg);
 785                         if (bits < 512 || bits > 32768) {
 786                                 printf("Bits has bad value.\n");
 787                                 exit(1);
 788                         }
 789                         break;
 790                 case 'l':
 791                         print_fingerprint = 1;
 792                         break;
 793                 case 'B':
 794                         print_bubblebabble = 1;
 795                         break;
 796                 case 'p':
 797                         change_passphrase = 1;
 798                         break;
 799                 case 'c':
 800                         change_comment = 1;
 801                         break;
 802                 case 'f':
 803                         strlcpy(identity_file, optarg, sizeof(identity_file));
 804                         have_identity = 1;
 805                         break;
 806                 case 'P':
 807                         identity_passphrase = optarg;
 808                         break;
 809                 case 'N':
 810                         identity_new_passphrase = optarg;
 811                         break;
 812                 case 'C':
 813                         identity_comment = optarg;
 814                         break;
 815                 case 'q':
 816                         quiet = 1;
 817                         break;
 818                 case 'R':
 819                         /* unused */
 820                         exit(0);
 821                         break;
 822                 case 'e':
 823                 case 'x':
 824                         /* export key */
 825                         convert_to_ssh2 = 1;
 826                         break;
 827                 case 'i':
 828                 case 'X':
 829                         /* import key */
 830                         convert_from_ssh2 = 1;
 831                         break;
 832                 case 'y':
 833                         print_public = 1;
 834                         break;
 835                 case 'd':
 836                         key_type_name = "dsa";
 837                         break;
 838                 case 't':
 839                         key_type_name = optarg;
 840                         break;
 841                 case 'D':
 842                         download = 1;
 843                 case 'U':
 844                         reader_id = optarg;
 845                         break;
 846                 case '?':
 847                 default:
 848                         usage();
 849                 }
 850         }
 851         if (optind < ac) {
 852                 printf("Too many arguments.\n");
 853                 usage();
 854         }
 855         if (change_passphrase && change_comment) {
 856                 printf("Can only have one of -p and -c.\n");
 857                 usage();
 858         }
 859         if (print_fingerprint || print_bubblebabble)
 860                 do_fingerprint(pw);
 861         if (change_passphrase)
 862                 do_change_passphrase(pw);
 863         if (change_comment)
 864                 do_change_comment(pw);
 865         if (convert_to_ssh2)
 866                 do_convert_to_ssh2(pw);
 867         if (convert_from_ssh2)
 868                 do_convert_from_ssh2(pw);
 869         if (print_public)
 870                 do_print_public(pw);
 871         if (reader_id != NULL) {
 872 #ifdef SMARTCARD
 873                 if (download)
 874                         do_download(pw, reader_id);
 875                 else
 876                         do_upload(pw, reader_id);
 877 #else /* SMARTCARD */
 878                 fatal("no support for smartcards.");
 879 #endif /* SMARTCARD */
 880         }
 881
 882         arc4random_stir();
 883
 884         if (key_type_name == NULL) {
 885                 printf("You must specify a key type (-t).\n");
 886                 usage();
 887         }
 888         type = key_type_from_name(key_type_name);
 889         if (type == KEY_UNSPEC) {
 890                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 891                 exit(1);
 892         }
 893         if (!quiet)
 894                 printf("Generating public/private %s key pair.\n", key_type_name);
 895         private = key_generate(type, bits);
 896         if (private == NULL) {
 897                 fprintf(stderr, "key_generate failed");
 898                 exit(1);
 899         }
 900         public  = key_from_private(private);
 901
 902         if (!have_identity)
 903                 ask_filename(pw, "Enter file in which to save the key");
 904
 905         /* Create ~/.ssh directory if it doesn\'t already exist. */
 906         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 907         if (strstr(identity_file, dotsshdir) != NULL &&
 908             stat(dotsshdir, &st) < 0) {
 909                 if (mkdir(dotsshdir, 0700) < 0)
 910                         error("Could not create directory '%s'.", dotsshdir);
 911                 else if (!quiet)
 912                         printf("Created directory '%s'.\n", dotsshdir);
 913         }
 914         /* If the file already exists, ask the user to confirm. */
 915         if (stat(identity_file, &st) >= 0) {
 916                 char yesno[3];
 917                 printf("%s already exists.\n", identity_file);
 918                 printf("Overwrite (y/n)? ");
 919                 fflush(stdout);
 920                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 921                         exit(1);
 922                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 923                         exit(1);
 924         }
 925         /* Ask for a passphrase (twice). */
 926         if (identity_passphrase)
 927                 passphrase1 = xstrdup(identity_passphrase);
 928         else if (identity_new_passphrase)
 929                 passphrase1 = xstrdup(identity_new_passphrase);
 930         else {
 931 passphrase_again:
 932                 passphrase1 =
 933                         read_passphrase("Enter passphrase (empty for no "
 934                             "passphrase): ", RP_ALLOW_STDIN);
 935                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 936                     RP_ALLOW_STDIN);
 937                 if (strcmp(passphrase1, passphrase2) != 0) {
 938                         /*
 939                          * The passphrases do not match.  Clear them and
 940                          * retry.
 941                          */
 942                         memset(passphrase1, 0, strlen(passphrase1));
 943                         memset(passphrase2, 0, strlen(passphrase2));
 944                         xfree(passphrase1);
 945                         xfree(passphrase2);
 946                         printf("Passphrases do not match.  Try again.\n");
 947                         goto passphrase_again;
 948                 }
 949                 /* Clear the other copy of the passphrase. */
 950                 memset(passphrase2, 0, strlen(passphrase2));
 951                 xfree(passphrase2);
 952         }
 953
 954         if (identity_comment) {
 955                 strlcpy(comment, identity_comment, sizeof(comment));
 956         } else {
 957                 /* Create default commend field for the passphrase. */
 958                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 959         }
 960
 961         /* Save the key with the given passphrase and comment. */
 962         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 963                 printf("Saving the key failed: %s.\n", identity_file);
 964                 memset(passphrase1, 0, strlen(passphrase1));
 965                 xfree(passphrase1);
 966                 exit(1);
 967         }
 968         /* Clear the passphrase. */
 969         memset(passphrase1, 0, strlen(passphrase1));
 970         xfree(passphrase1);
 971
 972         /* Clear the private key and the random number generator. */
 973         key_free(private);
 974         arc4random_stir();
 975
 976         if (!quiet)
 977                 printf("Your identification has been saved in %s.\n", identity_file);
 978
 979         strlcat(identity_file, ".pub", sizeof(identity_file));
 980         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 981         if (fd == -1) {
 982                 printf("Could not save your public key in %s\n", identity_file);
 983                 exit(1);
 984         }
 985         f = fdopen(fd, "w");
 986         if (f == NULL) {
 987                 printf("fdopen %s failed", identity_file);
 988                 exit(1);
 989         }
 990         if (!key_write(public, f))
 991                 fprintf(stderr, "write key failed");
 992         fprintf(f, " %s\n", comment);
 993         fclose(f);
 994
 995         if (!quiet) {
 996                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 997                 printf("Your public key has been saved in %s.\n",
 998                     identity_file);
 999                 printf("The key fingerprint is:\n");
1000                 printf("%s %s\n", fp, comment);
1001                 xfree(fp);
1002         }
1003
1004         key_free(public);
1005         exit(0);
1006 }