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 1.105 2003/05/14 18:16:20 jakob 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 int print_generic = 0;
  74
  75 char *key_type_name = NULL;
  76
  77 /* argv0 */
  78 #ifdef HAVE___PROGNAME
  79 extern char *__progname;
  80 #else
  81 char *__progname;
  82 #endif
  83
  84 char hostname[MAXHOSTNAMELEN];
  85
  86 static void
  87 ask_filename(struct passwd *pw, const char *prompt)
  88 {
  89         char buf[1024];
  90         char *name = NULL;
  91
  92         if (key_type_name == NULL)
  93                 name = _PATH_SSH_CLIENT_ID_RSA;
  94         else
  95                 switch (key_type_from_name(key_type_name)) {
  96                 case KEY_RSA1:
  97                         name = _PATH_SSH_CLIENT_IDENTITY;
  98                         break;
  99                 case KEY_DSA:
 100                         name = _PATH_SSH_CLIENT_ID_DSA;
 101                         break;
 102                 case KEY_RSA:
 103                         name = _PATH_SSH_CLIENT_ID_RSA;
 104                         break;
 105                 default:
 106                         fprintf(stderr, "bad key type");
 107                         exit(1);
 108                         break;
 109                 }
 110
 111         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 112         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 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 (k->type == KEY_RSA1) {
 168                 fprintf(stderr, "version 1 keys are not supported\n");
 169                 exit(1);
 170         }
 171         if (key_to_blob(k, &blob, &len) <= 0) {
 172                 fprintf(stderr, "key_to_blob failed\n");
 173                 exit(1);
 174         }
 175         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 176         fprintf(stdout,
 177             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 178             key_size(k), key_type(k),
 179             pw->pw_name, hostname);
 180         dump_base64(stdout, blob, len);
 181         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 182         key_free(k);
 183         xfree(blob);
 184         exit(0);
 185 }
 186
 187 static void
 188 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 189 {
 190         int bits = buffer_get_int(b);
 191         int bytes = (bits + 7) / 8;
 192
 193         if (buffer_len(b) < bytes)
 194                 fatal("buffer_get_bignum_bits: input buffer too small: "
 195                     "need %d have %d", bytes, buffer_len(b));
 196         BN_bin2bn(buffer_ptr(b), bytes, value);
 197         buffer_consume(b, bytes);
 198 }
 199
 200 static Key *
 201 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 202 {
 203         Buffer b;
 204         Key *key = NULL;
 205         char *type, *cipher;
 206         u_char *sig, data[] = "abcde12345";
 207         int magic, rlen, ktype, i1, i2, i3, i4;
 208         u_int slen;
 209         u_long e;
 210
 211         buffer_init(&b);
 212         buffer_append(&b, blob, blen);
 213
 214         magic  = buffer_get_int(&b);
 215         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 216                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 217                 buffer_free(&b);
 218                 return NULL;
 219         }
 220         i1 = buffer_get_int(&b);
 221         type   = buffer_get_string(&b, NULL);
 222         cipher = buffer_get_string(&b, NULL);
 223         i2 = buffer_get_int(&b);
 224         i3 = buffer_get_int(&b);
 225         i4 = buffer_get_int(&b);
 226         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 227         if (strcmp(cipher, "none") != 0) {
 228                 error("unsupported cipher %s", cipher);
 229                 xfree(cipher);
 230                 buffer_free(&b);
 231                 xfree(type);
 232                 return NULL;
 233         }
 234         xfree(cipher);
 235
 236         if (strstr(type, "dsa")) {
 237                 ktype = KEY_DSA;
 238         } else if (strstr(type, "rsa")) {
 239                 ktype = KEY_RSA;
 240         } else {
 241                 xfree(type);
 242                 return NULL;
 243         }
 244         key = key_new_private(ktype);
 245         xfree(type);
 246
 247         switch (key->type) {
 248         case KEY_DSA:
 249                 buffer_get_bignum_bits(&b, key->dsa->p);
 250                 buffer_get_bignum_bits(&b, key->dsa->g);
 251                 buffer_get_bignum_bits(&b, key->dsa->q);
 252                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 253                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 254                 break;
 255         case KEY_RSA:
 256                 e  = buffer_get_char(&b);
 257                 debug("e %lx", e);
 258                 if (e < 30) {
 259                         e <<= 8;
 260                         e += buffer_get_char(&b);
 261                         debug("e %lx", e);
 262                         e <<= 8;
 263                         e += buffer_get_char(&b);
 264                         debug("e %lx", e);
 265                 }
 266                 if (!BN_set_word(key->rsa->e, e)) {
 267                         buffer_free(&b);
 268                         key_free(key);
 269                         return NULL;
 270                 }
 271                 buffer_get_bignum_bits(&b, key->rsa->d);
 272                 buffer_get_bignum_bits(&b, key->rsa->n);
 273                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 274                 buffer_get_bignum_bits(&b, key->rsa->q);
 275                 buffer_get_bignum_bits(&b, key->rsa->p);
 276                 rsa_generate_additional_parameters(key->rsa);
 277                 break;
 278         }
 279         rlen = buffer_len(&b);
 280         if (rlen != 0)
 281                 error("do_convert_private_ssh2_from_blob: "
 282                     "remaining bytes in key blob %d", rlen);
 283         buffer_free(&b);
 284
 285         /* try the key */
 286         key_sign(key, &sig, &slen, data, sizeof(data));
 287         key_verify(key, sig, slen, data, sizeof(data));
 288         xfree(sig);
 289         return key;
 290 }
 291
 292 static void
 293 do_convert_from_ssh2(struct passwd *pw)
 294 {
 295         Key *k;
 296         int blen;
 297         u_int len;
 298         char line[1024], *p;
 299         u_char blob[8096];
 300         char encoded[8096];
 301         struct stat st;
 302         int escaped = 0, private = 0, ok;
 303         FILE *fp;
 304
 305         if (!have_identity)
 306                 ask_filename(pw, "Enter file in which the key is");
 307         if (stat(identity_file, &st) < 0) {
 308                 perror(identity_file);
 309                 exit(1);
 310         }
 311         fp = fopen(identity_file, "r");
 312         if (fp == NULL) {
 313                 perror(identity_file);
 314                 exit(1);
 315         }
 316         encoded[0] = '\0';
 317         while (fgets(line, sizeof(line), fp)) {
 318                 if (!(p = strchr(line, '\n'))) {
 319                         fprintf(stderr, "input line too long.\n");
 320                         exit(1);
 321                 }
 322                 if (p > line && p[-1] == '\\')
 323                         escaped++;
 324                 if (strncmp(line, "----", 4) == 0 ||
 325                     strstr(line, ": ") != NULL) {
 326                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 327                                 private = 1;
 328                         if (strstr(line, " END ") != NULL) {
 329                                 break;
 330                         }
 331                         /* fprintf(stderr, "ignore: %s", line); */
 332                         continue;
 333                 }
 334                 if (escaped) {
 335                         escaped--;
 336                         /* fprintf(stderr, "escaped: %s", line); */
 337                         continue;
 338                 }
 339                 *p = '\0';
 340                 strlcat(encoded, line, sizeof(encoded));
 341         }
 342         len = strlen(encoded);
 343         if (((len % 4) == 3) &&
 344             (encoded[len-1] == '=') &&
 345             (encoded[len-2] == '=') &&
 346             (encoded[len-3] == '='))
 347                 encoded[len-3] = '\0';
 348         blen = uudecode(encoded, blob, sizeof(blob));
 349         if (blen < 0) {
 350                 fprintf(stderr, "uudecode failed.\n");
 351                 exit(1);
 352         }
 353         k = private ?
 354             do_convert_private_ssh2_from_blob(blob, blen) :
 355             key_from_blob(blob, blen);
 356         if (k == NULL) {
 357                 fprintf(stderr, "decode blob failed.\n");
 358                 exit(1);
 359         }
 360         ok = private ?
 361             (k->type == KEY_DSA ?
 362                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 363                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 364             key_write(k, stdout);
 365         if (!ok) {
 366                 fprintf(stderr, "key write failed");
 367                 exit(1);
 368         }
 369         key_free(k);
 370         if (!private)
 371                 fprintf(stdout, "\n");
 372         fclose(fp);
 373         exit(0);
 374 }
 375
 376 static void
 377 do_print_public(struct passwd *pw)
 378 {
 379         Key *prv;
 380         struct stat st;
 381
 382         if (!have_identity)
 383                 ask_filename(pw, "Enter file in which the key is");
 384         if (stat(identity_file, &st) < 0) {
 385                 perror(identity_file);
 386                 exit(1);
 387         }
 388         prv = load_identity(identity_file);
 389         if (prv == NULL) {
 390                 fprintf(stderr, "load failed\n");
 391                 exit(1);
 392         }
 393         if (!key_write(prv, stdout))
 394                 fprintf(stderr, "key_write failed");
 395         key_free(prv);
 396         fprintf(stdout, "\n");
 397         exit(0);
 398 }
 399
 400 #ifdef SMARTCARD
 401 static void
 402 do_upload(struct passwd *pw, const char *sc_reader_id)
 403 {
 404         Key *prv = NULL;
 405         struct stat st;
 406         int ret;
 407
 408         if (!have_identity)
 409                 ask_filename(pw, "Enter file in which the key is");
 410         if (stat(identity_file, &st) < 0) {
 411                 perror(identity_file);
 412                 exit(1);
 413         }
 414         prv = load_identity(identity_file);
 415         if (prv == NULL) {
 416                 error("load failed");
 417                 exit(1);
 418         }
 419         ret = sc_put_key(prv, sc_reader_id);
 420         key_free(prv);
 421         if (ret < 0)
 422                 exit(1);
 423         logit("loading key done");
 424         exit(0);
 425 }
 426
 427 static void
 428 do_download(struct passwd *pw, const char *sc_reader_id)
 429 {
 430         Key **keys = NULL;
 431         int i;
 432
 433         keys = sc_get_keys(sc_reader_id, NULL);
 434         if (keys == NULL)
 435                 fatal("cannot read public key from smartcard");
 436         for (i = 0; keys[i]; i++) {
 437                 key_write(keys[i], stdout);
 438                 key_free(keys[i]);
 439                 fprintf(stdout, "\n");
 440         }
 441         xfree(keys);
 442         exit(0);
 443 }
 444 #endif /* SMARTCARD */
 445
 446 static void
 447 do_fingerprint(struct passwd *pw)
 448 {
 449         FILE *f;
 450         Key *public;
 451         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 452         int i, skip = 0, num = 1, invalid = 1;
 453         enum fp_rep rep;
 454         enum fp_type fptype;
 455         struct stat st;
 456
 457         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 458         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 459
 460         if (!have_identity)
 461                 ask_filename(pw, "Enter file in which the key is");
 462         if (stat(identity_file, &st) < 0) {
 463                 perror(identity_file);
 464                 exit(1);
 465         }
 466         public = key_load_public(identity_file, &comment);
 467         if (public != NULL) {
 468                 fp = key_fingerprint(public, fptype, rep);
 469                 printf("%u %s %s\n", key_size(public), fp, comment);
 470                 key_free(public);
 471                 xfree(comment);
 472                 xfree(fp);
 473                 exit(0);
 474         }
 475         if (comment)
 476                 xfree(comment);
 477
 478         f = fopen(identity_file, "r");
 479         if (f != NULL) {
 480                 while (fgets(line, sizeof(line), f)) {
 481                         i = strlen(line) - 1;
 482                         if (line[i] != '\n') {
 483                                 error("line %d too long: %.40s...", num, line);
 484                                 skip = 1;
 485                                 continue;
 486                         }
 487                         num++;
 488                         if (skip) {
 489                                 skip = 0;
 490                                 continue;
 491                         }
 492                         line[i] = '\0';
 493
 494                         /* Skip leading whitespace, empty and comment lines. */
 495                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 496                                 ;
 497                         if (!*cp || *cp == '\n' || *cp == '#')
 498                                 continue ;
 499                         i = strtol(cp, &ep, 10);
 500                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 501                                 int quoted = 0;
 502                                 comment = cp;
 503                                 for (; *cp && (quoted || (*cp != ' ' &&
 504                                     *cp != '\t')); cp++) {
 505                                         if (*cp == '\\' && cp[1] == '"')
 506                                                 cp++;   /* Skip both */
 507                                         else if (*cp == '"')
 508                                                 quoted = !quoted;
 509                                 }
 510                                 if (!*cp)
 511                                         continue;
 512                                 *cp++ = '\0';
 513                         }
 514                         ep = cp;
 515                         public = key_new(KEY_RSA1);
 516                         if (key_read(public, &cp) != 1) {
 517                                 cp = ep;
 518                                 key_free(public);
 519                                 public = key_new(KEY_UNSPEC);
 520                                 if (key_read(public, &cp) != 1) {
 521                                         key_free(public);
 522                                         continue;
 523                                 }
 524                         }
 525                         comment = *cp ? cp : comment;
 526                         fp = key_fingerprint(public, fptype, rep);
 527                         printf("%u %s %s\n", key_size(public), fp,
 528                             comment ? comment : "no comment");
 529                         xfree(fp);
 530                         key_free(public);
 531                         invalid = 0;
 532                 }
 533                 fclose(f);
 534         }
 535         if (invalid) {
 536                 printf("%s is not a public key file.\n", identity_file);
 537                 exit(1);
 538         }
 539         exit(0);
 540 }
 541
 542 /*
 543  * Perform changing a passphrase.  The argument is the passwd structure
 544  * for the current user.
 545  */
 546 static void
 547 do_change_passphrase(struct passwd *pw)
 548 {
 549         char *comment;
 550         char *old_passphrase, *passphrase1, *passphrase2;
 551         struct stat st;
 552         Key *private;
 553
 554         if (!have_identity)
 555                 ask_filename(pw, "Enter file in which the key is");
 556         if (stat(identity_file, &st) < 0) {
 557                 perror(identity_file);
 558                 exit(1);
 559         }
 560         /* Try to load the file with empty passphrase. */
 561         private = key_load_private(identity_file, "", &comment);
 562         if (private == NULL) {
 563                 if (identity_passphrase)
 564                         old_passphrase = xstrdup(identity_passphrase);
 565                 else
 566                         old_passphrase =
 567                             read_passphrase("Enter old passphrase: ",
 568                             RP_ALLOW_STDIN);
 569                 private = key_load_private(identity_file, old_passphrase,
 570                     &comment);
 571                 memset(old_passphrase, 0, strlen(old_passphrase));
 572                 xfree(old_passphrase);
 573                 if (private == NULL) {
 574                         printf("Bad passphrase.\n");
 575                         exit(1);
 576                 }
 577         }
 578         printf("Key has comment '%s'\n", comment);
 579
 580         /* Ask the new passphrase (twice). */
 581         if (identity_new_passphrase) {
 582                 passphrase1 = xstrdup(identity_new_passphrase);
 583                 passphrase2 = NULL;
 584         } else {
 585                 passphrase1 =
 586                         read_passphrase("Enter new passphrase (empty for no "
 587                             "passphrase): ", RP_ALLOW_STDIN);
 588                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 589                     RP_ALLOW_STDIN);
 590
 591                 /* Verify that they are the same. */
 592                 if (strcmp(passphrase1, passphrase2) != 0) {
 593                         memset(passphrase1, 0, strlen(passphrase1));
 594                         memset(passphrase2, 0, strlen(passphrase2));
 595                         xfree(passphrase1);
 596                         xfree(passphrase2);
 597                         printf("Pass phrases do not match.  Try again.\n");
 598                         exit(1);
 599                 }
 600                 /* Destroy the other copy. */
 601                 memset(passphrase2, 0, strlen(passphrase2));
 602                 xfree(passphrase2);
 603         }
 604
 605         /* Save the file using the new passphrase. */
 606         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 607                 printf("Saving the key failed: %s.\n", identity_file);
 608                 memset(passphrase1, 0, strlen(passphrase1));
 609                 xfree(passphrase1);
 610                 key_free(private);
 611                 xfree(comment);
 612                 exit(1);
 613         }
 614         /* Destroy the passphrase and the copy of the key in memory. */
 615         memset(passphrase1, 0, strlen(passphrase1));
 616         xfree(passphrase1);
 617         key_free(private);               /* Destroys contents */
 618         xfree(comment);
 619
 620         printf("Your identification has been saved with the new passphrase.\n");
 621         exit(0);
 622 }
 623
 624 #ifdef DNS
 625 /*
 626  * Print the SSHFP RR.
 627  */
 628 static void
 629 do_print_resource_record(struct passwd *pw, char *hostname)
 630 {
 631         Key *public;
 632         char *comment = NULL;
 633         struct stat st;
 634
 635         if (!have_identity)
 636                 ask_filename(pw, "Enter file in which the key is");
 637         if (stat(identity_file, &st) < 0) {
 638                 perror(identity_file);
 639                 exit(1);
 640         }
 641         public = key_load_public(identity_file, &comment);
 642         if (public != NULL) {
 643                 export_dns_rr(hostname, public, stdout, print_generic);
 644                 key_free(public);
 645                 xfree(comment);
 646                 exit(0);
 647         }
 648         if (comment)
 649                 xfree(comment);
 650
 651         printf("failed to read v2 public key from %s.\n", identity_file);
 652         exit(1);
 653 }
 654 #endif /* DNS */
 655
 656 /*
 657  * Change the comment of a private key file.
 658  */
 659 static void
 660 do_change_comment(struct passwd *pw)
 661 {
 662         char new_comment[1024], *comment, *passphrase;
 663         Key *private;
 664         Key *public;
 665         struct stat st;
 666         FILE *f;
 667         int fd;
 668
 669         if (!have_identity)
 670                 ask_filename(pw, "Enter file in which the key is");
 671         if (stat(identity_file, &st) < 0) {
 672                 perror(identity_file);
 673                 exit(1);
 674         }
 675         private = key_load_private(identity_file, "", &comment);
 676         if (private == NULL) {
 677                 if (identity_passphrase)
 678                         passphrase = xstrdup(identity_passphrase);
 679                 else if (identity_new_passphrase)
 680                         passphrase = xstrdup(identity_new_passphrase);
 681                 else
 682                         passphrase = read_passphrase("Enter passphrase: ",
 683                             RP_ALLOW_STDIN);
 684                 /* Try to load using the passphrase. */
 685                 private = key_load_private(identity_file, passphrase, &comment);
 686                 if (private == NULL) {
 687                         memset(passphrase, 0, strlen(passphrase));
 688                         xfree(passphrase);
 689                         printf("Bad passphrase.\n");
 690                         exit(1);
 691                 }
 692         } else {
 693                 passphrase = xstrdup("");
 694         }
 695         if (private->type != KEY_RSA1) {
 696                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 697                 key_free(private);
 698                 exit(1);
 699         }
 700         printf("Key now has comment '%s'\n", comment);
 701
 702         if (identity_comment) {
 703                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 704         } else {
 705                 printf("Enter new comment: ");
 706                 fflush(stdout);
 707                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 708                         memset(passphrase, 0, strlen(passphrase));
 709                         key_free(private);
 710                         exit(1);
 711                 }
 712                 if (strchr(new_comment, '\n'))
 713                         *strchr(new_comment, '\n') = 0;
 714         }
 715
 716         /* Save the file using the new passphrase. */
 717         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 718                 printf("Saving the key failed: %s.\n", identity_file);
 719                 memset(passphrase, 0, strlen(passphrase));
 720                 xfree(passphrase);
 721                 key_free(private);
 722                 xfree(comment);
 723                 exit(1);
 724         }
 725         memset(passphrase, 0, strlen(passphrase));
 726         xfree(passphrase);
 727         public = key_from_private(private);
 728         key_free(private);
 729
 730         strlcat(identity_file, ".pub", sizeof(identity_file));
 731         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 732         if (fd == -1) {
 733                 printf("Could not save your public key in %s\n", identity_file);
 734                 exit(1);
 735         }
 736         f = fdopen(fd, "w");
 737         if (f == NULL) {
 738                 printf("fdopen %s failed", identity_file);
 739                 exit(1);
 740         }
 741         if (!key_write(public, f))
 742                 fprintf(stderr, "write key failed");
 743         key_free(public);
 744         fprintf(f, " %s\n", new_comment);
 745         fclose(f);
 746
 747         xfree(comment);
 748
 749         printf("The comment in your key file has been changed.\n");
 750         exit(0);
 751 }
 752
 753 static void
 754 usage(void)
 755 {
 756         fprintf(stderr, "Usage: %s [options]\n", __progname);
 757         fprintf(stderr, "Options:\n");
 758         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 759         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 760         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 761         fprintf(stderr, "  -f filename Filename of the key file.\n");
 762         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
 763         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 764         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 765         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 766         fprintf(stderr, "  -q          Quiet.\n");
 767         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 768         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 769         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 770         fprintf(stderr, "  -C comment  Provide new comment.\n");
 771         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 772         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 773 #ifdef DNS
 774         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
 775 #endif /* DNS */
 776 #ifdef SMARTCARD
 777         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 778         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 779 #endif /* SMARTCARD */
 780
 781         exit(1);
 782 }
 783
 784 /*
 785  * Main program for key management.
 786  */
 787 int
 788 main(int ac, char **av)
 789 {
 790         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 791         char *reader_id = NULL;
 792         char *resource_record_hostname = NULL;
 793         Key *private, *public;
 794         struct passwd *pw;
 795         struct stat st;
 796         int opt, type, fd, download = 0;
 797         FILE *f;
 798
 799         extern int optind;
 800         extern char *optarg;
 801
 802         __progname = get_progname(av[0]);
 803
 804         SSLeay_add_all_algorithms();
 805         init_rng();
 806         seed_rng();
 807
 808         /* we need this for the home * directory.  */
 809         pw = getpwuid(getuid());
 810         if (!pw) {
 811                 printf("You don't exist, go away!\n");
 812                 exit(1);
 813         }
 814         if (gethostname(hostname, sizeof(hostname)) < 0) {
 815                 perror("gethostname");
 816                 exit(1);
 817         }
 818
 819         while ((opt = getopt(ac, av, "degiqpclBRxXyb:f:t:U:D:P:N:C:r:")) != -1) {
 820                 switch (opt) {
 821                 case 'b':
 822                         bits = atoi(optarg);
 823                         if (bits < 512 || bits > 32768) {
 824                                 printf("Bits has bad value.\n");
 825                                 exit(1);
 826                         }
 827                         break;
 828                 case 'l':
 829                         print_fingerprint = 1;
 830                         break;
 831                 case 'B':
 832                         print_bubblebabble = 1;
 833                         break;
 834                 case 'p':
 835                         change_passphrase = 1;
 836                         break;
 837                 case 'c':
 838                         change_comment = 1;
 839                         break;
 840                 case 'f':
 841                         strlcpy(identity_file, optarg, sizeof(identity_file));
 842                         have_identity = 1;
 843                         break;
 844                 case 'g':
 845                         print_generic = 1;
 846                         break;
 847                 case 'P':
 848                         identity_passphrase = optarg;
 849                         break;
 850                 case 'N':
 851                         identity_new_passphrase = optarg;
 852                         break;
 853                 case 'C':
 854                         identity_comment = optarg;
 855                         break;
 856                 case 'q':
 857                         quiet = 1;
 858                         break;
 859                 case 'R':
 860                         /* unused */
 861                         exit(0);
 862                         break;
 863                 case 'e':
 864                 case 'x':
 865                         /* export key */
 866                         convert_to_ssh2 = 1;
 867                         break;
 868                 case 'i':
 869                 case 'X':
 870                         /* import key */
 871                         convert_from_ssh2 = 1;
 872                         break;
 873                 case 'y':
 874                         print_public = 1;
 875                         break;
 876                 case 'd':
 877                         key_type_name = "dsa";
 878                         break;
 879                 case 't':
 880                         key_type_name = optarg;
 881                         break;
 882                 case 'D':
 883                         download = 1;
 884                 case 'U':
 885                         reader_id = optarg;
 886                         break;
 887                 case 'r':
 888                         resource_record_hostname = optarg;
 889                         break;
 890                 case '?':
 891                 default:
 892                         usage();
 893                 }
 894         }
 895         if (optind < ac) {
 896                 printf("Too many arguments.\n");
 897                 usage();
 898         }
 899         if (change_passphrase && change_comment) {
 900                 printf("Can only have one of -p and -c.\n");
 901                 usage();
 902         }
 903         if (print_fingerprint || print_bubblebabble)
 904                 do_fingerprint(pw);
 905         if (change_passphrase)
 906                 do_change_passphrase(pw);
 907         if (change_comment)
 908                 do_change_comment(pw);
 909         if (convert_to_ssh2)
 910                 do_convert_to_ssh2(pw);
 911         if (convert_from_ssh2)
 912                 do_convert_from_ssh2(pw);
 913         if (print_public)
 914                 do_print_public(pw);
 915         if (resource_record_hostname != NULL) {
 916 #ifdef DNS
 917                 do_print_resource_record(pw, resource_record_hostname);
 918 #else /* DNS */
 919                 fatal("no DNS support.");
 920 #endif /* DNS */
 921         }
 922         if (reader_id != NULL) {
 923 #ifdef SMARTCARD
 924                 if (download)
 925                         do_download(pw, reader_id);
 926                 else
 927                         do_upload(pw, reader_id);
 928 #else /* SMARTCARD */
 929                 fatal("no support for smartcards.");
 930 #endif /* SMARTCARD */
 931         }
 932
 933         arc4random_stir();
 934
 935         if (key_type_name == NULL) {
 936                 printf("You must specify a key type (-t).\n");
 937                 usage();
 938         }
 939         type = key_type_from_name(key_type_name);
 940         if (type == KEY_UNSPEC) {
 941                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 942                 exit(1);
 943         }
 944         if (!quiet)
 945                 printf("Generating public/private %s key pair.\n", key_type_name);
 946         private = key_generate(type, bits);
 947         if (private == NULL) {
 948                 fprintf(stderr, "key_generate failed");
 949                 exit(1);
 950         }
 951         public  = key_from_private(private);
 952
 953         if (!have_identity)
 954                 ask_filename(pw, "Enter file in which to save the key");
 955
 956         /* Create ~/.ssh directory if it doesn\'t already exist. */
 957         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 958         if (strstr(identity_file, dotsshdir) != NULL &&
 959             stat(dotsshdir, &st) < 0) {
 960                 if (mkdir(dotsshdir, 0700) < 0)
 961                         error("Could not create directory '%s'.", dotsshdir);
 962                 else if (!quiet)
 963                         printf("Created directory '%s'.\n", dotsshdir);
 964         }
 965         /* If the file already exists, ask the user to confirm. */
 966         if (stat(identity_file, &st) >= 0) {
 967                 char yesno[3];
 968                 printf("%s already exists.\n", identity_file);
 969                 printf("Overwrite (y/n)? ");
 970                 fflush(stdout);
 971                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 972                         exit(1);
 973                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 974                         exit(1);
 975         }
 976         /* Ask for a passphrase (twice). */
 977         if (identity_passphrase)
 978                 passphrase1 = xstrdup(identity_passphrase);
 979         else if (identity_new_passphrase)
 980                 passphrase1 = xstrdup(identity_new_passphrase);
 981         else {
 982 passphrase_again:
 983                 passphrase1 =
 984                         read_passphrase("Enter passphrase (empty for no "
 985                             "passphrase): ", RP_ALLOW_STDIN);
 986                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 987                     RP_ALLOW_STDIN);
 988                 if (strcmp(passphrase1, passphrase2) != 0) {
 989                         /*
 990                          * The passphrases do not match.  Clear them and
 991                          * retry.
 992                          */
 993                         memset(passphrase1, 0, strlen(passphrase1));
 994                         memset(passphrase2, 0, strlen(passphrase2));
 995                         xfree(passphrase1);
 996                         xfree(passphrase2);
 997                         printf("Passphrases do not match.  Try again.\n");
 998                         goto passphrase_again;
 999                 }
1000                 /* Clear the other copy of the passphrase. */
1001                 memset(passphrase2, 0, strlen(passphrase2));
1002                 xfree(passphrase2);
1003         }
1004
1005         if (identity_comment) {
1006                 strlcpy(comment, identity_comment, sizeof(comment));
1007         } else {
1008                 /* Create default commend field for the passphrase. */
1009                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1010         }
1011
1012         /* Save the key with the given passphrase and comment. */
1013         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1014                 printf("Saving the key failed: %s.\n", identity_file);
1015                 memset(passphrase1, 0, strlen(passphrase1));
1016                 xfree(passphrase1);
1017                 exit(1);
1018         }
1019         /* Clear the passphrase. */
1020         memset(passphrase1, 0, strlen(passphrase1));
1021         xfree(passphrase1);
1022
1023         /* Clear the private key and the random number generator. */
1024         key_free(private);
1025         arc4random_stir();
1026
1027         if (!quiet)
1028                 printf("Your identification has been saved in %s.\n", identity_file);
1029
1030         strlcat(identity_file, ".pub", sizeof(identity_file));
1031         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1032         if (fd == -1) {
1033                 printf("Could not save your public key in %s\n", identity_file);
1034                 exit(1);
1035         }
1036         f = fdopen(fd, "w");
1037         if (f == NULL) {
1038                 printf("fdopen %s failed", identity_file);
1039                 exit(1);
1040         }
1041         if (!key_write(public, f))
1042                 fprintf(stderr, "write key failed");
1043         fprintf(f, " %s\n", comment);
1044         fclose(f);
1045
1046         if (!quiet) {
1047                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1048                 printf("Your public key has been saved in %s.\n",
1049                     identity_file);
1050                 printf("The key fingerprint is:\n");
1051                 printf("%s %s\n", fp, comment);
1052                 xfree(fp);
1053         }
1054
1055         key_free(public);
1056         exit(0);
1057 }