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 1.95 2002/03/21 16:54:53 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         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         blen = uudecode(encoded, blob, sizeof(blob));
 338         if (blen < 0) {
 339                 fprintf(stderr, "uudecode failed.\n");
 340                 exit(1);
 341         }
 342         k = private ?
 343             do_convert_private_ssh2_from_blob(blob, blen) :
 344             key_from_blob(blob, blen);
 345         if (k == NULL) {
 346                 fprintf(stderr, "decode blob failed.\n");
 347                 exit(1);
 348         }
 349         ok = private ?
 350             (k->type == KEY_DSA ?
 351                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 352                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 353             key_write(k, stdout);
 354         if (!ok) {
 355                 fprintf(stderr, "key write failed");
 356                 exit(1);
 357         }
 358         key_free(k);
 359         if (!private)
 360                 fprintf(stdout, "\n");
 361         fclose(fp);
 362         exit(0);
 363 }
 364
 365 static void
 366 do_print_public(struct passwd *pw)
 367 {
 368         Key *prv;
 369         struct stat st;
 370
 371         if (!have_identity)
 372                 ask_filename(pw, "Enter file in which the key is");
 373         if (stat(identity_file, &st) < 0) {
 374                 perror(identity_file);
 375                 exit(1);
 376         }
 377         prv = load_identity(identity_file);
 378         if (prv == NULL) {
 379                 fprintf(stderr, "load failed\n");
 380                 exit(1);
 381         }
 382         if (!key_write(prv, stdout))
 383                 fprintf(stderr, "key_write failed");
 384         key_free(prv);
 385         fprintf(stdout, "\n");
 386         exit(0);
 387 }
 388
 389 #ifdef SMARTCARD
 390 static void
 391 do_upload(struct passwd *pw, const char *sc_reader_id)
 392 {
 393         Key *prv = NULL;
 394         struct stat st;
 395         int ret;
 396
 397         if (!have_identity)
 398                 ask_filename(pw, "Enter file in which the key is");
 399         if (stat(identity_file, &st) < 0) {
 400                 perror(identity_file);
 401                 exit(1);
 402         }
 403         prv = load_identity(identity_file);
 404         if (prv == NULL) {
 405                 error("load failed");
 406                 exit(1);
 407         }
 408         ret = sc_put_key(prv, sc_reader_id);
 409         key_free(prv);
 410         if (ret < 0)
 411                 exit(1);
 412         log("loading key done");
 413         exit(0);
 414 }
 415
 416 static void
 417 do_download(struct passwd *pw, const char *sc_reader_id)
 418 {
 419         Key *pub = NULL;
 420
 421         pub = sc_get_key(sc_reader_id);
 422         if (pub == NULL)
 423                 fatal("cannot read public key from smartcard");
 424         key_write(pub, stdout);
 425         key_free(pub);
 426         fprintf(stdout, "\n");
 427         exit(0);
 428 }
 429 #endif /* SMARTCARD */
 430
 431 static void
 432 do_fingerprint(struct passwd *pw)
 433 {
 434         FILE *f;
 435         Key *public;
 436         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 437         int i, skip = 0, num = 1, invalid = 1;
 438         enum fp_rep rep;
 439         enum fp_type fptype;
 440         struct stat st;
 441
 442         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 443         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 444
 445         if (!have_identity)
 446                 ask_filename(pw, "Enter file in which the key is");
 447         if (stat(identity_file, &st) < 0) {
 448                 perror(identity_file);
 449                 exit(1);
 450         }
 451         public = key_load_public(identity_file, &comment);
 452         if (public != NULL) {
 453                 fp = key_fingerprint(public, fptype, rep);
 454                 printf("%d %s %s\n", key_size(public), fp, comment);
 455                 key_free(public);
 456                 xfree(comment);
 457                 xfree(fp);
 458                 exit(0);
 459         }
 460         if (comment)
 461                 xfree(comment);
 462
 463         f = fopen(identity_file, "r");
 464         if (f != NULL) {
 465                 while (fgets(line, sizeof(line), f)) {
 466                         i = strlen(line) - 1;
 467                         if (line[i] != '\n') {
 468                                 error("line %d too long: %.40s...", num, line);
 469                                 skip = 1;
 470                                 continue;
 471                         }
 472                         num++;
 473                         if (skip) {
 474                                 skip = 0;
 475                                 continue;
 476                         }
 477                         line[i] = '\0';
 478
 479                         /* Skip leading whitespace, empty and comment lines. */
 480                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 481                                 ;
 482                         if (!*cp || *cp == '\n' || *cp == '#')
 483                                 continue ;
 484                         i = strtol(cp, &ep, 10);
 485                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 486                                 int quoted = 0;
 487                                 comment = cp;
 488                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 489                                         if (*cp == '\\' && cp[1] == '"')
 490                                                 cp++;   /* Skip both */
 491                                         else if (*cp == '"')
 492                                                 quoted = !quoted;
 493                                 }
 494                                 if (!*cp)
 495                                         continue;
 496                                 *cp++ = '\0';
 497                         }
 498                         ep = cp;
 499                         public = key_new(KEY_RSA1);
 500                         if (key_read(public, &cp) != 1) {
 501                                 cp = ep;
 502                                 key_free(public);
 503                                 public = key_new(KEY_UNSPEC);
 504                                 if (key_read(public, &cp) != 1) {
 505                                         key_free(public);
 506                                         continue;
 507                                 }
 508                         }
 509                         comment = *cp ? cp : comment;
 510                         fp = key_fingerprint(public, fptype, rep);
 511                         printf("%d %s %s\n", key_size(public), fp,
 512                             comment ? comment : "no comment");
 513                         xfree(fp);
 514                         key_free(public);
 515                         invalid = 0;
 516                 }
 517                 fclose(f);
 518         }
 519         if (invalid) {
 520                 printf("%s is not a public key file.\n", identity_file);
 521                 exit(1);
 522         }
 523         exit(0);
 524 }
 525
 526 /*
 527  * Perform changing a passphrase.  The argument is the passwd structure
 528  * for the current user.
 529  */
 530 static void
 531 do_change_passphrase(struct passwd *pw)
 532 {
 533         char *comment;
 534         char *old_passphrase, *passphrase1, *passphrase2;
 535         struct stat st;
 536         Key *private;
 537
 538         if (!have_identity)
 539                 ask_filename(pw, "Enter file in which the key is");
 540         if (stat(identity_file, &st) < 0) {
 541                 perror(identity_file);
 542                 exit(1);
 543         }
 544         /* Try to load the file with empty passphrase. */
 545         private = key_load_private(identity_file, "", &comment);
 546         if (private == NULL) {
 547                 if (identity_passphrase)
 548                         old_passphrase = xstrdup(identity_passphrase);
 549                 else
 550                         old_passphrase =
 551                             read_passphrase("Enter old passphrase: ",
 552                             RP_ALLOW_STDIN);
 553                 private = key_load_private(identity_file, old_passphrase,
 554                     &comment);
 555                 memset(old_passphrase, 0, strlen(old_passphrase));
 556                 xfree(old_passphrase);
 557                 if (private == NULL) {
 558                         printf("Bad passphrase.\n");
 559                         exit(1);
 560                 }
 561         }
 562         printf("Key has comment '%s'\n", comment);
 563
 564         /* Ask the new passphrase (twice). */
 565         if (identity_new_passphrase) {
 566                 passphrase1 = xstrdup(identity_new_passphrase);
 567                 passphrase2 = NULL;
 568         } else {
 569                 passphrase1 =
 570                         read_passphrase("Enter new passphrase (empty for no "
 571                             "passphrase): ", RP_ALLOW_STDIN);
 572                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 573                     RP_ALLOW_STDIN);
 574
 575                 /* Verify that they are the same. */
 576                 if (strcmp(passphrase1, passphrase2) != 0) {
 577                         memset(passphrase1, 0, strlen(passphrase1));
 578                         memset(passphrase2, 0, strlen(passphrase2));
 579                         xfree(passphrase1);
 580                         xfree(passphrase2);
 581                         printf("Pass phrases do not match.  Try again.\n");
 582                         exit(1);
 583                 }
 584                 /* Destroy the other copy. */
 585                 memset(passphrase2, 0, strlen(passphrase2));
 586                 xfree(passphrase2);
 587         }
 588
 589         /* Save the file using the new passphrase. */
 590         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 591                 printf("Saving the key failed: %s.\n", identity_file);
 592                 memset(passphrase1, 0, strlen(passphrase1));
 593                 xfree(passphrase1);
 594                 key_free(private);
 595                 xfree(comment);
 596                 exit(1);
 597         }
 598         /* Destroy the passphrase and the copy of the key in memory. */
 599         memset(passphrase1, 0, strlen(passphrase1));
 600         xfree(passphrase1);
 601         key_free(private);               /* Destroys contents */
 602         xfree(comment);
 603
 604         printf("Your identification has been saved with the new passphrase.\n");
 605         exit(0);
 606 }
 607
 608 /*
 609  * Change the comment of a private key file.
 610  */
 611 static void
 612 do_change_comment(struct passwd *pw)
 613 {
 614         char new_comment[1024], *comment, *passphrase;
 615         Key *private;
 616         Key *public;
 617         struct stat st;
 618         FILE *f;
 619         int fd;
 620
 621         if (!have_identity)
 622                 ask_filename(pw, "Enter file in which the key is");
 623         if (stat(identity_file, &st) < 0) {
 624                 perror(identity_file);
 625                 exit(1);
 626         }
 627         private = key_load_private(identity_file, "", &comment);
 628         if (private == NULL) {
 629                 if (identity_passphrase)
 630                         passphrase = xstrdup(identity_passphrase);
 631                 else if (identity_new_passphrase)
 632                         passphrase = xstrdup(identity_new_passphrase);
 633                 else
 634                         passphrase = read_passphrase("Enter passphrase: ",
 635                             RP_ALLOW_STDIN);
 636                 /* Try to load using the passphrase. */
 637                 private = key_load_private(identity_file, passphrase, &comment);
 638                 if (private == NULL) {
 639                         memset(passphrase, 0, strlen(passphrase));
 640                         xfree(passphrase);
 641                         printf("Bad passphrase.\n");
 642                         exit(1);
 643                 }
 644         } else {
 645                 passphrase = xstrdup("");
 646         }
 647         if (private->type != KEY_RSA1) {
 648                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 649                 key_free(private);
 650                 exit(1);
 651         }
 652         printf("Key now has comment '%s'\n", comment);
 653
 654         if (identity_comment) {
 655                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 656         } else {
 657                 printf("Enter new comment: ");
 658                 fflush(stdout);
 659                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 660                         memset(passphrase, 0, strlen(passphrase));
 661                         key_free(private);
 662                         exit(1);
 663                 }
 664                 if (strchr(new_comment, '\n'))
 665                         *strchr(new_comment, '\n') = 0;
 666         }
 667
 668         /* Save the file using the new passphrase. */
 669         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 670                 printf("Saving the key failed: %s.\n", identity_file);
 671                 memset(passphrase, 0, strlen(passphrase));
 672                 xfree(passphrase);
 673                 key_free(private);
 674                 xfree(comment);
 675                 exit(1);
 676         }
 677         memset(passphrase, 0, strlen(passphrase));
 678         xfree(passphrase);
 679         public = key_from_private(private);
 680         key_free(private);
 681
 682         strlcat(identity_file, ".pub", sizeof(identity_file));
 683         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 684         if (fd == -1) {
 685                 printf("Could not save your public key in %s\n", identity_file);
 686                 exit(1);
 687         }
 688         f = fdopen(fd, "w");
 689         if (f == NULL) {
 690                 printf("fdopen %s failed", identity_file);
 691                 exit(1);
 692         }
 693         if (!key_write(public, f))
 694                 fprintf(stderr, "write key failed");
 695         key_free(public);
 696         fprintf(f, " %s\n", new_comment);
 697         fclose(f);
 698
 699         xfree(comment);
 700
 701         printf("The comment in your key file has been changed.\n");
 702         exit(0);
 703 }
 704
 705 static void
 706 usage(void)
 707 {
 708         fprintf(stderr, "Usage: %s [options]\n", __progname);
 709         fprintf(stderr, "Options:\n");
 710         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 711         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 712         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 713         fprintf(stderr, "  -f filename Filename of the key file.\n");
 714         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 715         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 716         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 717         fprintf(stderr, "  -q          Quiet.\n");
 718         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 719         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 720         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 721         fprintf(stderr, "  -C comment  Provide new comment.\n");
 722         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 723         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 724 #ifdef SMARTCARD
 725         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 726         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 727 #endif /* SMARTCARD */
 728
 729         exit(1);
 730 }
 731
 732 /*
 733  * Main program for key management.
 734  */
 735 int
 736 main(int ac, char **av)
 737 {
 738         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 739         char *reader_id = NULL;
 740         Key *private, *public;
 741         struct passwd *pw;
 742         struct stat st;
 743         int opt, type, fd, download = 0;
 744         FILE *f;
 745
 746         extern int optind;
 747         extern char *optarg;
 748
 749         __progname = get_progname(av[0]);
 750
 751         SSLeay_add_all_algorithms();
 752
 753         /* we need this for the home * directory.  */
 754         pw = getpwuid(getuid());
 755         if (!pw) {
 756                 printf("You don't exist, go away!\n");
 757                 exit(1);
 758         }
 759         if (gethostname(hostname, sizeof(hostname)) < 0) {
 760                 perror("gethostname");
 761                 exit(1);
 762         }
 763
 764         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
 765                 switch (opt) {
 766                 case 'b':
 767                         bits = atoi(optarg);
 768                         if (bits < 512 || bits > 32768) {
 769                                 printf("Bits has bad value.\n");
 770                                 exit(1);
 771                         }
 772                         break;
 773                 case 'l':
 774                         print_fingerprint = 1;
 775                         break;
 776                 case 'B':
 777                         print_bubblebabble = 1;
 778                         break;
 779                 case 'p':
 780                         change_passphrase = 1;
 781                         break;
 782                 case 'c':
 783                         change_comment = 1;
 784                         break;
 785                 case 'f':
 786                         strlcpy(identity_file, optarg, sizeof(identity_file));
 787                         have_identity = 1;
 788                         break;
 789                 case 'P':
 790                         identity_passphrase = optarg;
 791                         break;
 792                 case 'N':
 793                         identity_new_passphrase = optarg;
 794                         break;
 795                 case 'C':
 796                         identity_comment = optarg;
 797                         break;
 798                 case 'q':
 799                         quiet = 1;
 800                         break;
 801                 case 'R':
 802                         /* unused */
 803                         exit(0);
 804                         break;
 805                 case 'e':
 806                 case 'x':
 807                         /* export key */
 808                         convert_to_ssh2 = 1;
 809                         break;
 810                 case 'i':
 811                 case 'X':
 812                         /* import key */
 813                         convert_from_ssh2 = 1;
 814                         break;
 815                 case 'y':
 816                         print_public = 1;
 817                         break;
 818                 case 'd':
 819                         key_type_name = "dsa";
 820                         break;
 821                 case 't':
 822                         key_type_name = optarg;
 823                         break;
 824                 case 'D':
 825                         download = 1;
 826                 case 'U':
 827                         reader_id = optarg;
 828                         break;
 829                 case '?':
 830                 default:
 831                         usage();
 832                 }
 833         }
 834         if (optind < ac) {
 835                 printf("Too many arguments.\n");
 836                 usage();
 837         }
 838         if (change_passphrase && change_comment) {
 839                 printf("Can only have one of -p and -c.\n");
 840                 usage();
 841         }
 842         if (print_fingerprint || print_bubblebabble)
 843                 do_fingerprint(pw);
 844         if (change_passphrase)
 845                 do_change_passphrase(pw);
 846         if (convert_to_ssh2)
 847                 do_convert_to_ssh2(pw);
 848         if (change_comment)
 849                 do_change_comment(pw);
 850         if (print_public)
 851                 do_print_public(pw);
 852         if (reader_id != NULL) {
 853 #ifdef SMARTCARD
 854                 if (download)
 855                         do_download(pw, reader_id);
 856                 else
 857                         do_upload(pw, reader_id);
 858 #else /* SMARTCARD */
 859                 fatal("no support for smartcards.");
 860 #endif /* SMARTCARD */
 861         }
 862
 863         init_rng();
 864         seed_rng();
 865         arc4random_stir();
 866
 867         if (convert_from_ssh2)
 868                 do_convert_from_ssh2(pw);
 869
 870         if (key_type_name == NULL) {
 871                 printf("You must specify a key type (-t).\n");
 872                 usage();
 873         }
 874         type = key_type_from_name(key_type_name);
 875         if (type == KEY_UNSPEC) {
 876                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 877                 exit(1);
 878         }
 879         if (!quiet)
 880                 printf("Generating public/private %s key pair.\n", key_type_name);
 881         private = key_generate(type, bits);
 882         if (private == NULL) {
 883                 fprintf(stderr, "key_generate failed");
 884                 exit(1);
 885         }
 886         public  = key_from_private(private);
 887
 888         if (!have_identity)
 889                 ask_filename(pw, "Enter file in which to save the key");
 890
 891         /* Create ~/.ssh directory if it doesn\'t already exist. */
 892         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 893         if (strstr(identity_file, dotsshdir) != NULL &&
 894             stat(dotsshdir, &st) < 0) {
 895                 if (mkdir(dotsshdir, 0700) < 0)
 896                         error("Could not create directory '%s'.", dotsshdir);
 897                 else if (!quiet)
 898                         printf("Created directory '%s'.\n", dotsshdir);
 899         }
 900         /* If the file already exists, ask the user to confirm. */
 901         if (stat(identity_file, &st) >= 0) {
 902                 char yesno[3];
 903                 printf("%s already exists.\n", identity_file);
 904                 printf("Overwrite (y/n)? ");
 905                 fflush(stdout);
 906                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 907                         exit(1);
 908                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 909                         exit(1);
 910         }
 911         /* Ask for a passphrase (twice). */
 912         if (identity_passphrase)
 913                 passphrase1 = xstrdup(identity_passphrase);
 914         else if (identity_new_passphrase)
 915                 passphrase1 = xstrdup(identity_new_passphrase);
 916         else {
 917 passphrase_again:
 918                 passphrase1 =
 919                         read_passphrase("Enter passphrase (empty for no "
 920                             "passphrase): ", RP_ALLOW_STDIN);
 921                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 922                     RP_ALLOW_STDIN);
 923                 if (strcmp(passphrase1, passphrase2) != 0) {
 924                         /*
 925                          * The passphrases do not match.  Clear them and
 926                          * retry.
 927                          */
 928                         memset(passphrase1, 0, strlen(passphrase1));
 929                         memset(passphrase2, 0, strlen(passphrase2));
 930                         xfree(passphrase1);
 931                         xfree(passphrase2);
 932                         printf("Passphrases do not match.  Try again.\n");
 933                         goto passphrase_again;
 934                 }
 935                 /* Clear the other copy of the passphrase. */
 936                 memset(passphrase2, 0, strlen(passphrase2));
 937                 xfree(passphrase2);
 938         }
 939
 940         if (identity_comment) {
 941                 strlcpy(comment, identity_comment, sizeof(comment));
 942         } else {
 943                 /* Create default commend field for the passphrase. */
 944                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 945         }
 946
 947         /* Save the key with the given passphrase and comment. */
 948         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 949                 printf("Saving the key failed: %s.\n", identity_file);
 950                 memset(passphrase1, 0, strlen(passphrase1));
 951                 xfree(passphrase1);
 952                 exit(1);
 953         }
 954         /* Clear the passphrase. */
 955         memset(passphrase1, 0, strlen(passphrase1));
 956         xfree(passphrase1);
 957
 958         /* Clear the private key and the random number generator. */
 959         key_free(private);
 960         arc4random_stir();
 961
 962         if (!quiet)
 963                 printf("Your identification has been saved in %s.\n", identity_file);
 964
 965         strlcat(identity_file, ".pub", sizeof(identity_file));
 966         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 967         if (fd == -1) {
 968                 printf("Could not save your public key in %s\n", identity_file);
 969                 exit(1);
 970         }
 971         f = fdopen(fd, "w");
 972         if (f == NULL) {
 973                 printf("fdopen %s failed", identity_file);
 974                 exit(1);
 975         }
 976         if (!key_write(public, f))
 977                 fprintf(stderr, "write key failed");
 978         fprintf(f, " %s\n", comment);
 979         fclose(f);
 980
 981         if (!quiet) {
 982                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 983                 printf("Your public key has been saved in %s.\n",
 984                     identity_file);
 985                 printf("The key fingerprint is:\n");
 986                 printf("%s %s\n", fp, comment);
 987                 xfree(fp);
 988         }
 989
 990         key_free(public);
 991         exit(0);
 992 }