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 1.99 2002/06/09 13:32:01 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         fflush(stderr);
 113         if (fgets(buf, sizeof(buf), stdin) == NULL)
 114                 exit(1);
 115         if (strchr(buf, '\n'))
 116                 *strchr(buf, '\n') = 0;
 117         if (strcmp(buf, "") != 0)
 118                 strlcpy(identity_file, buf, sizeof(identity_file));
 119         have_identity = 1;
 120 }
 121
 122 static Key *
 123 load_identity(char *filename)
 124 {
 125         char *pass;
 126         Key *prv;
 127
 128         prv = key_load_private(filename, "", NULL);
 129         if (prv == NULL) {
 130                 if (identity_passphrase)
 131                         pass = xstrdup(identity_passphrase);
 132                 else
 133                         pass = read_passphrase("Enter passphrase: ",
 134                             RP_ALLOW_STDIN);
 135                 prv = key_load_private(filename, pass, NULL);
 136                 memset(pass, 0, strlen(pass));
 137                 xfree(pass);
 138         }
 139         return prv;
 140 }
 141
 142 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 143 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 144 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 145 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 146
 147 static void
 148 do_convert_to_ssh2(struct passwd *pw)
 149 {
 150         Key *k;
 151         u_int len;
 152         u_char *blob;
 153         struct stat st;
 154
 155         if (!have_identity)
 156                 ask_filename(pw, "Enter file in which the key is");
 157         if (stat(identity_file, &st) < 0) {
 158                 perror(identity_file);
 159                 exit(1);
 160         }
 161         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 162                 if ((k = load_identity(identity_file)) == NULL) {
 163                         fprintf(stderr, "load failed\n");
 164                         exit(1);
 165                 }
 166         }
 167         if (key_to_blob(k, &blob, &len) <= 0) {
 168                 fprintf(stderr, "key_to_blob failed\n");
 169                 exit(1);
 170         }
 171         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 172         fprintf(stdout,
 173             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 174             key_size(k), key_type(k),
 175             pw->pw_name, hostname);
 176         dump_base64(stdout, blob, len);
 177         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 178         key_free(k);
 179         xfree(blob);
 180         exit(0);
 181 }
 182
 183 static void
 184 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 185 {
 186         int bits = buffer_get_int(b);
 187         int bytes = (bits + 7) / 8;
 188
 189         if (buffer_len(b) < bytes)
 190                 fatal("buffer_get_bignum_bits: input buffer too small: "
 191                     "need %d have %d", bytes, buffer_len(b));
 192         BN_bin2bn(buffer_ptr(b), bytes, value);
 193         buffer_consume(b, bytes);
 194 }
 195
 196 static Key *
 197 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 198 {
 199         Buffer b;
 200         Key *key = NULL;
 201         char *type, *cipher;
 202         u_char *sig, data[] = "abcde12345";
 203         int magic, rlen, ktype, i1, i2, i3, i4;
 204         u_int slen;
 205         u_long e;
 206
 207         buffer_init(&b);
 208         buffer_append(&b, blob, blen);
 209
 210         magic  = buffer_get_int(&b);
 211         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 212                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 213                 buffer_free(&b);
 214                 return NULL;
 215         }
 216         i1 = buffer_get_int(&b);
 217         type   = buffer_get_string(&b, NULL);
 218         cipher = buffer_get_string(&b, NULL);
 219         i2 = buffer_get_int(&b);
 220         i3 = buffer_get_int(&b);
 221         i4 = buffer_get_int(&b);
 222         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 223         if (strcmp(cipher, "none") != 0) {
 224                 error("unsupported cipher %s", cipher);
 225                 xfree(cipher);
 226                 buffer_free(&b);
 227                 xfree(type);
 228                 return NULL;
 229         }
 230         xfree(cipher);
 231
 232         if (strstr(type, "dsa")) {
 233                 ktype = KEY_DSA;
 234         } else if (strstr(type, "rsa")) {
 235                 ktype = KEY_RSA;
 236         } else {
 237                 xfree(type);
 238                 return NULL;
 239         }
 240         key = key_new_private(ktype);
 241         xfree(type);
 242
 243         switch (key->type) {
 244         case KEY_DSA:
 245                 buffer_get_bignum_bits(&b, key->dsa->p);
 246                 buffer_get_bignum_bits(&b, key->dsa->g);
 247                 buffer_get_bignum_bits(&b, key->dsa->q);
 248                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 249                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 250                 break;
 251         case KEY_RSA:
 252                 e  = buffer_get_char(&b);
 253                 debug("e %lx", e);
 254                 if (e < 30) {
 255                         e <<= 8;
 256                         e += buffer_get_char(&b);
 257                         debug("e %lx", e);
 258                         e <<= 8;
 259                         e += buffer_get_char(&b);
 260                         debug("e %lx", e);
 261                 }
 262                 if (!BN_set_word(key->rsa->e, e)) {
 263                         buffer_free(&b);
 264                         key_free(key);
 265                         return NULL;
 266                 }
 267                 buffer_get_bignum_bits(&b, key->rsa->d);
 268                 buffer_get_bignum_bits(&b, key->rsa->n);
 269                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 270                 buffer_get_bignum_bits(&b, key->rsa->q);
 271                 buffer_get_bignum_bits(&b, key->rsa->p);
 272                 rsa_generate_additional_parameters(key->rsa);
 273                 break;
 274         }
 275         rlen = buffer_len(&b);
 276         if (rlen != 0)
 277                 error("do_convert_private_ssh2_from_blob: "
 278                     "remaining bytes in key blob %d", rlen);
 279         buffer_free(&b);
 280
 281         /* try the key */
 282         key_sign(key, &sig, &slen, data, sizeof(data));
 283         key_verify(key, sig, slen, data, sizeof(data));
 284         xfree(sig);
 285         return key;
 286 }
 287
 288 static void
 289 do_convert_from_ssh2(struct passwd *pw)
 290 {
 291         Key *k;
 292         int blen;
 293         u_int len;
 294         char line[1024], *p;
 295         u_char blob[8096];
 296         char encoded[8096];
 297         struct stat st;
 298         int escaped = 0, private = 0, ok;
 299         FILE *fp;
 300
 301         if (!have_identity)
 302                 ask_filename(pw, "Enter file in which the key is");
 303         if (stat(identity_file, &st) < 0) {
 304                 perror(identity_file);
 305                 exit(1);
 306         }
 307         fp = fopen(identity_file, "r");
 308         if (fp == NULL) {
 309                 perror(identity_file);
 310                 exit(1);
 311         }
 312         encoded[0] = '\0';
 313         while (fgets(line, sizeof(line), fp)) {
 314                 if (!(p = strchr(line, '\n'))) {
 315                         fprintf(stderr, "input line too long.\n");
 316                         exit(1);
 317                 }
 318                 if (p > line && p[-1] == '\\')
 319                         escaped++;
 320                 if (strncmp(line, "----", 4) == 0 ||
 321                     strstr(line, ": ") != NULL) {
 322                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 323                                 private = 1;
 324                         if (strstr(line, " END ") != NULL) {
 325                                 break;
 326                         }
 327                         /* fprintf(stderr, "ignore: %s", line); */
 328                         continue;
 329                 }
 330                 if (escaped) {
 331                         escaped--;
 332                         /* fprintf(stderr, "escaped: %s", line); */
 333                         continue;
 334                 }
 335                 *p = '\0';
 336                 strlcat(encoded, line, sizeof(encoded));
 337         }
 338         len = strlen(encoded);
 339         if (((len % 4) == 3) &&
 340             (encoded[len-1] == '=') &&
 341             (encoded[len-2] == '=') &&
 342             (encoded[len-3] == '='))
 343                 encoded[len-3] = '\0';
 344         blen = uudecode(encoded, blob, sizeof(blob));
 345         if (blen < 0) {
 346                 fprintf(stderr, "uudecode failed.\n");
 347                 exit(1);
 348         }
 349         k = private ?
 350             do_convert_private_ssh2_from_blob(blob, blen) :
 351             key_from_blob(blob, blen);
 352         if (k == NULL) {
 353                 fprintf(stderr, "decode blob failed.\n");
 354                 exit(1);
 355         }
 356         ok = private ?
 357             (k->type == KEY_DSA ?
 358                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 359                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 360             key_write(k, stdout);
 361         if (!ok) {
 362                 fprintf(stderr, "key write failed");
 363                 exit(1);
 364         }
 365         key_free(k);
 366         if (!private)
 367                 fprintf(stdout, "\n");
 368         fclose(fp);
 369         exit(0);
 370 }
 371
 372 static void
 373 do_print_public(struct passwd *pw)
 374 {
 375         Key *prv;
 376         struct stat st;
 377
 378         if (!have_identity)
 379                 ask_filename(pw, "Enter file in which the key is");
 380         if (stat(identity_file, &st) < 0) {
 381                 perror(identity_file);
 382                 exit(1);
 383         }
 384         prv = load_identity(identity_file);
 385         if (prv == NULL) {
 386                 fprintf(stderr, "load failed\n");
 387                 exit(1);
 388         }
 389         if (!key_write(prv, stdout))
 390                 fprintf(stderr, "key_write failed");
 391         key_free(prv);
 392         fprintf(stdout, "\n");
 393         exit(0);
 394 }
 395
 396 #ifdef SMARTCARD
 397 static void
 398 do_upload(struct passwd *pw, const char *sc_reader_id)
 399 {
 400         Key *prv = NULL;
 401         struct stat st;
 402         int ret;
 403
 404         if (!have_identity)
 405                 ask_filename(pw, "Enter file in which the key is");
 406         if (stat(identity_file, &st) < 0) {
 407                 perror(identity_file);
 408                 exit(1);
 409         }
 410         prv = load_identity(identity_file);
 411         if (prv == NULL) {
 412                 error("load failed");
 413                 exit(1);
 414         }
 415         ret = sc_put_key(prv, sc_reader_id);
 416         key_free(prv);
 417         if (ret < 0)
 418                 exit(1);
 419         log("loading key done");
 420         exit(0);
 421 }
 422
 423 static void
 424 do_download(struct passwd *pw, const char *sc_reader_id)
 425 {
 426         Key **keys = NULL;
 427         int i;
 428
 429         keys = sc_get_keys(sc_reader_id, NULL);
 430         if (keys == NULL)
 431                 fatal("cannot read public key from smartcard");
 432         for (i = 0; keys[i]; i++) {
 433                 key_write(keys[i], stdout);
 434                 key_free(keys[i]);
 435                 fprintf(stdout, "\n");
 436         }
 437         xfree(keys);
 438         exit(0);
 439 }
 440 #endif /* SMARTCARD */
 441
 442 static void
 443 do_fingerprint(struct passwd *pw)
 444 {
 445         FILE *f;
 446         Key *public;
 447         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 448         int i, skip = 0, num = 1, invalid = 1;
 449         enum fp_rep rep;
 450         enum fp_type fptype;
 451         struct stat st;
 452
 453         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 454         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 455
 456         if (!have_identity)
 457                 ask_filename(pw, "Enter file in which the key is");
 458         if (stat(identity_file, &st) < 0) {
 459                 perror(identity_file);
 460                 exit(1);
 461         }
 462         public = key_load_public(identity_file, &comment);
 463         if (public != NULL) {
 464                 fp = key_fingerprint(public, fptype, rep);
 465                 printf("%d %s %s\n", key_size(public), fp, comment);
 466                 key_free(public);
 467                 xfree(comment);
 468                 xfree(fp);
 469                 exit(0);
 470         }
 471         if (comment)
 472                 xfree(comment);
 473
 474         f = fopen(identity_file, "r");
 475         if (f != NULL) {
 476                 while (fgets(line, sizeof(line), f)) {
 477                         i = strlen(line) - 1;
 478                         if (line[i] != '\n') {
 479                                 error("line %d too long: %.40s...", num, line);
 480                                 skip = 1;
 481                                 continue;
 482                         }
 483                         num++;
 484                         if (skip) {
 485                                 skip = 0;
 486                                 continue;
 487                         }
 488                         line[i] = '\0';
 489
 490                         /* Skip leading whitespace, empty and comment lines. */
 491                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 492                                 ;
 493                         if (!*cp || *cp == '\n' || *cp == '#')
 494                                 continue ;
 495                         i = strtol(cp, &ep, 10);
 496                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 497                                 int quoted = 0;
 498                                 comment = cp;
 499                                 for (; *cp && (quoted || (*cp != ' ' && *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("%d %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
 764         /* we need this for the home * directory.  */
 765         pw = getpwuid(getuid());
 766         if (!pw) {
 767                 printf("You don't exist, go away!\n");
 768                 exit(1);
 769         }
 770         if (gethostname(hostname, sizeof(hostname)) < 0) {
 771                 perror("gethostname");
 772                 exit(1);
 773         }
 774
 775         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
 776                 switch (opt) {
 777                 case 'b':
 778                         bits = atoi(optarg);
 779                         if (bits < 512 || bits > 32768) {
 780                                 printf("Bits has bad value.\n");
 781                                 exit(1);
 782                         }
 783                         break;
 784                 case 'l':
 785                         print_fingerprint = 1;
 786                         break;
 787                 case 'B':
 788                         print_bubblebabble = 1;
 789                         break;
 790                 case 'p':
 791                         change_passphrase = 1;
 792                         break;
 793                 case 'c':
 794                         change_comment = 1;
 795                         break;
 796                 case 'f':
 797                         strlcpy(identity_file, optarg, sizeof(identity_file));
 798                         have_identity = 1;
 799                         break;
 800                 case 'P':
 801                         identity_passphrase = optarg;
 802                         break;
 803                 case 'N':
 804                         identity_new_passphrase = optarg;
 805                         break;
 806                 case 'C':
 807                         identity_comment = optarg;
 808                         break;
 809                 case 'q':
 810                         quiet = 1;
 811                         break;
 812                 case 'R':
 813                         /* unused */
 814                         exit(0);
 815                         break;
 816                 case 'e':
 817                 case 'x':
 818                         /* export key */
 819                         convert_to_ssh2 = 1;
 820                         break;
 821                 case 'i':
 822                 case 'X':
 823                         /* import key */
 824                         convert_from_ssh2 = 1;
 825                         break;
 826                 case 'y':
 827                         print_public = 1;
 828                         break;
 829                 case 'd':
 830                         key_type_name = "dsa";
 831                         break;
 832                 case 't':
 833                         key_type_name = optarg;
 834                         break;
 835                 case 'D':
 836                         download = 1;
 837                 case 'U':
 838                         reader_id = optarg;
 839                         break;
 840                 case '?':
 841                 default:
 842                         usage();
 843                 }
 844         }
 845         if (optind < ac) {
 846                 printf("Too many arguments.\n");
 847                 usage();
 848         }
 849         if (change_passphrase && change_comment) {
 850                 printf("Can only have one of -p and -c.\n");
 851                 usage();
 852         }
 853         if (print_fingerprint || print_bubblebabble)
 854                 do_fingerprint(pw);
 855         if (change_passphrase)
 856                 do_change_passphrase(pw);
 857         if (convert_to_ssh2)
 858                 do_convert_to_ssh2(pw);
 859         if (change_comment)
 860                 do_change_comment(pw);
 861         if (print_public)
 862                 do_print_public(pw);
 863         if (reader_id != NULL) {
 864 #ifdef SMARTCARD
 865                 if (download)
 866                         do_download(pw, reader_id);
 867                 else
 868                         do_upload(pw, reader_id);
 869 #else /* SMARTCARD */
 870                 fatal("no support for smartcards.");
 871 #endif /* SMARTCARD */
 872         }
 873
 874         init_rng();
 875         seed_rng();
 876         arc4random_stir();
 877
 878         if (convert_from_ssh2)
 879                 do_convert_from_ssh2(pw);
 880
 881         if (key_type_name == NULL) {
 882                 printf("You must specify a key type (-t).\n");
 883                 usage();
 884         }
 885         type = key_type_from_name(key_type_name);
 886         if (type == KEY_UNSPEC) {
 887                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 888                 exit(1);
 889         }
 890         if (!quiet)
 891                 printf("Generating public/private %s key pair.\n", key_type_name);
 892         private = key_generate(type, bits);
 893         if (private == NULL) {
 894                 fprintf(stderr, "key_generate failed");
 895                 exit(1);
 896         }
 897         public  = key_from_private(private);
 898
 899         if (!have_identity)
 900                 ask_filename(pw, "Enter file in which to save the key");
 901
 902         /* Create ~/.ssh directory if it doesn\'t already exist. */
 903         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 904         if (strstr(identity_file, dotsshdir) != NULL &&
 905             stat(dotsshdir, &st) < 0) {
 906                 if (mkdir(dotsshdir, 0700) < 0)
 907                         error("Could not create directory '%s'.", dotsshdir);
 908                 else if (!quiet)
 909                         printf("Created directory '%s'.\n", dotsshdir);
 910         }
 911         /* If the file already exists, ask the user to confirm. */
 912         if (stat(identity_file, &st) >= 0) {
 913                 char yesno[3];
 914                 printf("%s already exists.\n", identity_file);
 915                 printf("Overwrite (y/n)? ");
 916                 fflush(stdout);
 917                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 918                         exit(1);
 919                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 920                         exit(1);
 921         }
 922         /* Ask for a passphrase (twice). */
 923         if (identity_passphrase)
 924                 passphrase1 = xstrdup(identity_passphrase);
 925         else if (identity_new_passphrase)
 926                 passphrase1 = xstrdup(identity_new_passphrase);
 927         else {
 928 passphrase_again:
 929                 passphrase1 =
 930                         read_passphrase("Enter passphrase (empty for no "
 931                             "passphrase): ", RP_ALLOW_STDIN);
 932                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 933                     RP_ALLOW_STDIN);
 934                 if (strcmp(passphrase1, passphrase2) != 0) {
 935                         /*
 936                          * The passphrases do not match.  Clear them and
 937                          * retry.
 938                          */
 939                         memset(passphrase1, 0, strlen(passphrase1));
 940                         memset(passphrase2, 0, strlen(passphrase2));
 941                         xfree(passphrase1);
 942                         xfree(passphrase2);
 943                         printf("Passphrases do not match.  Try again.\n");
 944                         goto passphrase_again;
 945                 }
 946                 /* Clear the other copy of the passphrase. */
 947                 memset(passphrase2, 0, strlen(passphrase2));
 948                 xfree(passphrase2);
 949         }
 950
 951         if (identity_comment) {
 952                 strlcpy(comment, identity_comment, sizeof(comment));
 953         } else {
 954                 /* Create default commend field for the passphrase. */
 955                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 956         }
 957
 958         /* Save the key with the given passphrase and comment. */
 959         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 960                 printf("Saving the key failed: %s.\n", identity_file);
 961                 memset(passphrase1, 0, strlen(passphrase1));
 962                 xfree(passphrase1);
 963                 exit(1);
 964         }
 965         /* Clear the passphrase. */
 966         memset(passphrase1, 0, strlen(passphrase1));
 967         xfree(passphrase1);
 968
 969         /* Clear the private key and the random number generator. */
 970         key_free(private);
 971         arc4random_stir();
 972
 973         if (!quiet)
 974                 printf("Your identification has been saved in %s.\n", identity_file);
 975
 976         strlcat(identity_file, ".pub", sizeof(identity_file));
 977         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 978         if (fd == -1) {
 979                 printf("Could not save your public key in %s\n", identity_file);
 980                 exit(1);
 981         }
 982         f = fdopen(fd, "w");
 983         if (f == NULL) {
 984                 printf("fdopen %s failed", identity_file);
 985                 exit(1);
 986         }
 987         if (!key_write(public, f))
 988                 fprintf(stderr, "write key failed");
 989         fprintf(f, " %s\n", comment);
 990         fclose(f);
 991
 992         if (!quiet) {
 993                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 994                 printf("Your public key has been saved in %s.\n",
 995                     identity_file);
 996                 printf("The key fingerprint is:\n");
 997                 printf("%s %s\n", fp, comment);
 998                 xfree(fp);
 999         }
1000
1001         key_free(public);
1002         exit(0);
1003 }