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 1.115 2004/05/09 00:06:47 djm 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 "misc.h"
  30
  31 #ifdef SMARTCARD
  32 #include "scard.h"
  33 #endif
  34 #include "dns.h"
  35
  36 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  37 int bits = 1024;
  38
  39 /*
  40  * Flag indicating that we just want to change the passphrase.  This can be
  41  * set on the command line.
  42  */
  43 int change_passphrase = 0;
  44
  45 /*
  46  * Flag indicating that we just want to change the comment.  This can be set
  47  * on the command line.
  48  */
  49 int change_comment = 0;
  50
  51 int quiet = 0;
  52
  53 /* Flag indicating that we just want to see the key fingerprint */
  54 int print_fingerprint = 0;
  55 int print_bubblebabble = 0;
  56
  57 /* The identity file name, given on the command line or entered by the user. */
  58 char identity_file[1024];
  59 int have_identity = 0;
  60
  61 /* This is set to the passphrase if given on the command line. */
  62 char *identity_passphrase = NULL;
  63
  64 /* This is set to the new passphrase if given on the command line. */
  65 char *identity_new_passphrase = NULL;
  66
  67 /* This is set to the new comment if given on the command line. */
  68 char *identity_comment = NULL;
  69
  70 /* Dump public key file in format used by real and the original SSH 2 */
  71 int convert_to_ssh2 = 0;
  72 int convert_from_ssh2 = 0;
  73 int print_public = 0;
  74 int print_generic = 0;
  75
  76 char *key_type_name = NULL;
  77
  78 /* argv0 */
  79 #ifdef HAVE___PROGNAME
  80 extern char *__progname;
  81 #else
  82 char *__progname;
  83 #endif
  84
  85 char hostname[MAXHOSTNAMELEN];
  86
  87 /* moduli.c */
  88 int gen_candidates(FILE *, int, int, BIGNUM *);
  89 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
  90
  91 static void
  92 ask_filename(struct passwd *pw, const char *prompt)
  93 {
  94         char buf[1024];
  95         char *name = NULL;
  96
  97         if (key_type_name == NULL)
  98                 name = _PATH_SSH_CLIENT_ID_RSA;
  99         else
 100                 switch (key_type_from_name(key_type_name)) {
 101                 case KEY_RSA1:
 102                         name = _PATH_SSH_CLIENT_IDENTITY;
 103                         break;
 104                 case KEY_DSA:
 105                         name = _PATH_SSH_CLIENT_ID_DSA;
 106                         break;
 107                 case KEY_RSA:
 108                         name = _PATH_SSH_CLIENT_ID_RSA;
 109                         break;
 110                 default:
 111                         fprintf(stderr, "bad key type");
 112                         exit(1);
 113                         break;
 114                 }
 115
 116         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 117         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 118         if (fgets(buf, sizeof(buf), stdin) == NULL)
 119                 exit(1);
 120         if (strchr(buf, '\n'))
 121                 *strchr(buf, '\n') = 0;
 122         if (strcmp(buf, "") != 0)
 123                 strlcpy(identity_file, buf, sizeof(identity_file));
 124         have_identity = 1;
 125 }
 126
 127 static Key *
 128 load_identity(char *filename)
 129 {
 130         char *pass;
 131         Key *prv;
 132
 133         prv = key_load_private(filename, "", NULL);
 134         if (prv == NULL) {
 135                 if (identity_passphrase)
 136                         pass = xstrdup(identity_passphrase);
 137                 else
 138                         pass = read_passphrase("Enter passphrase: ",
 139                             RP_ALLOW_STDIN);
 140                 prv = key_load_private(filename, pass, NULL);
 141                 memset(pass, 0, strlen(pass));
 142                 xfree(pass);
 143         }
 144         return prv;
 145 }
 146
 147 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 148 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 149 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 150 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 151
 152 static void
 153 do_convert_to_ssh2(struct passwd *pw)
 154 {
 155         Key *k;
 156         u_int len;
 157         u_char *blob;
 158         struct stat st;
 159
 160         if (!have_identity)
 161                 ask_filename(pw, "Enter file in which the key is");
 162         if (stat(identity_file, &st) < 0) {
 163                 perror(identity_file);
 164                 exit(1);
 165         }
 166         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 167                 if ((k = load_identity(identity_file)) == NULL) {
 168                         fprintf(stderr, "load failed\n");
 169                         exit(1);
 170                 }
 171         }
 172         if (k->type == KEY_RSA1) {
 173                 fprintf(stderr, "version 1 keys are not supported\n");
 174                 exit(1);
 175         }
 176         if (key_to_blob(k, &blob, &len) <= 0) {
 177                 fprintf(stderr, "key_to_blob failed\n");
 178                 exit(1);
 179         }
 180         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 181         fprintf(stdout,
 182             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 183             key_size(k), key_type(k),
 184             pw->pw_name, hostname);
 185         dump_base64(stdout, blob, len);
 186         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 187         key_free(k);
 188         xfree(blob);
 189         exit(0);
 190 }
 191
 192 static void
 193 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 194 {
 195         u_int bits = buffer_get_int(b);
 196         u_int bytes = (bits + 7) / 8;
 197
 198         if (buffer_len(b) < bytes)
 199                 fatal("buffer_get_bignum_bits: input buffer too small: "
 200                     "need %d have %d", bytes, buffer_len(b));
 201         BN_bin2bn(buffer_ptr(b), bytes, value);
 202         buffer_consume(b, bytes);
 203 }
 204
 205 static Key *
 206 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 207 {
 208         Buffer b;
 209         Key *key = NULL;
 210         char *type, *cipher;
 211         u_char *sig, data[] = "abcde12345";
 212         int magic, rlen, ktype, i1, i2, i3, i4;
 213         u_int slen;
 214         u_long e;
 215
 216         buffer_init(&b);
 217         buffer_append(&b, blob, blen);
 218
 219         magic  = buffer_get_int(&b);
 220         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 221                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 222                 buffer_free(&b);
 223                 return NULL;
 224         }
 225         i1 = buffer_get_int(&b);
 226         type   = buffer_get_string(&b, NULL);
 227         cipher = buffer_get_string(&b, NULL);
 228         i2 = buffer_get_int(&b);
 229         i3 = buffer_get_int(&b);
 230         i4 = buffer_get_int(&b);
 231         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 232         if (strcmp(cipher, "none") != 0) {
 233                 error("unsupported cipher %s", cipher);
 234                 xfree(cipher);
 235                 buffer_free(&b);
 236                 xfree(type);
 237                 return NULL;
 238         }
 239         xfree(cipher);
 240
 241         if (strstr(type, "dsa")) {
 242                 ktype = KEY_DSA;
 243         } else if (strstr(type, "rsa")) {
 244                 ktype = KEY_RSA;
 245         } else {
 246                 xfree(type);
 247                 return NULL;
 248         }
 249         key = key_new_private(ktype);
 250         xfree(type);
 251
 252         switch (key->type) {
 253         case KEY_DSA:
 254                 buffer_get_bignum_bits(&b, key->dsa->p);
 255                 buffer_get_bignum_bits(&b, key->dsa->g);
 256                 buffer_get_bignum_bits(&b, key->dsa->q);
 257                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 258                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 259                 break;
 260         case KEY_RSA:
 261                 e  = buffer_get_char(&b);
 262                 debug("e %lx", e);
 263                 if (e < 30) {
 264                         e <<= 8;
 265                         e += buffer_get_char(&b);
 266                         debug("e %lx", e);
 267                         e <<= 8;
 268                         e += buffer_get_char(&b);
 269                         debug("e %lx", e);
 270                 }
 271                 if (!BN_set_word(key->rsa->e, e)) {
 272                         buffer_free(&b);
 273                         key_free(key);
 274                         return NULL;
 275                 }
 276                 buffer_get_bignum_bits(&b, key->rsa->d);
 277                 buffer_get_bignum_bits(&b, key->rsa->n);
 278                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 279                 buffer_get_bignum_bits(&b, key->rsa->q);
 280                 buffer_get_bignum_bits(&b, key->rsa->p);
 281                 rsa_generate_additional_parameters(key->rsa);
 282                 break;
 283         }
 284         rlen = buffer_len(&b);
 285         if (rlen != 0)
 286                 error("do_convert_private_ssh2_from_blob: "
 287                     "remaining bytes in key blob %d", rlen);
 288         buffer_free(&b);
 289
 290         /* try the key */
 291         key_sign(key, &sig, &slen, data, sizeof(data));
 292         key_verify(key, sig, slen, data, sizeof(data));
 293         xfree(sig);
 294         return key;
 295 }
 296
 297 static void
 298 do_convert_from_ssh2(struct passwd *pw)
 299 {
 300         Key *k;
 301         int blen;
 302         u_int len;
 303         char line[1024], *p;
 304         u_char blob[8096];
 305         char encoded[8096];
 306         struct stat st;
 307         int escaped = 0, private = 0, ok;
 308         FILE *fp;
 309
 310         if (!have_identity)
 311                 ask_filename(pw, "Enter file in which the key is");
 312         if (stat(identity_file, &st) < 0) {
 313                 perror(identity_file);
 314                 exit(1);
 315         }
 316         fp = fopen(identity_file, "r");
 317         if (fp == NULL) {
 318                 perror(identity_file);
 319                 exit(1);
 320         }
 321         encoded[0] = '\0';
 322         while (fgets(line, sizeof(line), fp)) {
 323                 if (!(p = strchr(line, '\n'))) {
 324                         fprintf(stderr, "input line too long.\n");
 325                         exit(1);
 326                 }
 327                 if (p > line && p[-1] == '\\')
 328                         escaped++;
 329                 if (strncmp(line, "----", 4) == 0 ||
 330                     strstr(line, ": ") != NULL) {
 331                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 332                                 private = 1;
 333                         if (strstr(line, " END ") != NULL) {
 334                                 break;
 335                         }
 336                         /* fprintf(stderr, "ignore: %s", line); */
 337                         continue;
 338                 }
 339                 if (escaped) {
 340                         escaped--;
 341                         /* fprintf(stderr, "escaped: %s", line); */
 342                         continue;
 343                 }
 344                 *p = '\0';
 345                 strlcat(encoded, line, sizeof(encoded));
 346         }
 347         len = strlen(encoded);
 348         if (((len % 4) == 3) &&
 349             (encoded[len-1] == '=') &&
 350             (encoded[len-2] == '=') &&
 351             (encoded[len-3] == '='))
 352                 encoded[len-3] = '\0';
 353         blen = uudecode(encoded, blob, sizeof(blob));
 354         if (blen < 0) {
 355                 fprintf(stderr, "uudecode failed.\n");
 356                 exit(1);
 357         }
 358         k = private ?
 359             do_convert_private_ssh2_from_blob(blob, blen) :
 360             key_from_blob(blob, blen);
 361         if (k == NULL) {
 362                 fprintf(stderr, "decode blob failed.\n");
 363                 exit(1);
 364         }
 365         ok = private ?
 366             (k->type == KEY_DSA ?
 367                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 368                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 369             key_write(k, stdout);
 370         if (!ok) {
 371                 fprintf(stderr, "key write failed");
 372                 exit(1);
 373         }
 374         key_free(k);
 375         if (!private)
 376                 fprintf(stdout, "\n");
 377         fclose(fp);
 378         exit(0);
 379 }
 380
 381 static void
 382 do_print_public(struct passwd *pw)
 383 {
 384         Key *prv;
 385         struct stat st;
 386
 387         if (!have_identity)
 388                 ask_filename(pw, "Enter file in which the key is");
 389         if (stat(identity_file, &st) < 0) {
 390                 perror(identity_file);
 391                 exit(1);
 392         }
 393         prv = load_identity(identity_file);
 394         if (prv == NULL) {
 395                 fprintf(stderr, "load failed\n");
 396                 exit(1);
 397         }
 398         if (!key_write(prv, stdout))
 399                 fprintf(stderr, "key_write failed");
 400         key_free(prv);
 401         fprintf(stdout, "\n");
 402         exit(0);
 403 }
 404
 405 #ifdef SMARTCARD
 406 static void
 407 do_upload(struct passwd *pw, const char *sc_reader_id)
 408 {
 409         Key *prv = NULL;
 410         struct stat st;
 411         int ret;
 412
 413         if (!have_identity)
 414                 ask_filename(pw, "Enter file in which the key is");
 415         if (stat(identity_file, &st) < 0) {
 416                 perror(identity_file);
 417                 exit(1);
 418         }
 419         prv = load_identity(identity_file);
 420         if (prv == NULL) {
 421                 error("load failed");
 422                 exit(1);
 423         }
 424         ret = sc_put_key(prv, sc_reader_id);
 425         key_free(prv);
 426         if (ret < 0)
 427                 exit(1);
 428         logit("loading key done");
 429         exit(0);
 430 }
 431
 432 static void
 433 do_download(struct passwd *pw, const char *sc_reader_id)
 434 {
 435         Key **keys = NULL;
 436         int i;
 437
 438         keys = sc_get_keys(sc_reader_id, NULL);
 439         if (keys == NULL)
 440                 fatal("cannot read public key from smartcard");
 441         for (i = 0; keys[i]; i++) {
 442                 key_write(keys[i], stdout);
 443                 key_free(keys[i]);
 444                 fprintf(stdout, "\n");
 445         }
 446         xfree(keys);
 447         exit(0);
 448 }
 449 #endif /* SMARTCARD */
 450
 451 static void
 452 do_fingerprint(struct passwd *pw)
 453 {
 454         FILE *f;
 455         Key *public;
 456         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 457         int i, skip = 0, num = 1, invalid = 1;
 458         enum fp_rep rep;
 459         enum fp_type fptype;
 460         struct stat st;
 461
 462         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 463         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 464
 465         if (!have_identity)
 466                 ask_filename(pw, "Enter file in which the key is");
 467         if (stat(identity_file, &st) < 0) {
 468                 perror(identity_file);
 469                 exit(1);
 470         }
 471         public = key_load_public(identity_file, &comment);
 472         if (public != NULL) {
 473                 fp = key_fingerprint(public, fptype, rep);
 474                 printf("%u %s %s\n", key_size(public), fp, comment);
 475                 key_free(public);
 476                 xfree(comment);
 477                 xfree(fp);
 478                 exit(0);
 479         }
 480         if (comment)
 481                 xfree(comment);
 482
 483         f = fopen(identity_file, "r");
 484         if (f != NULL) {
 485                 while (fgets(line, sizeof(line), f)) {
 486                         i = strlen(line) - 1;
 487                         if (line[i] != '\n') {
 488                                 error("line %d too long: %.40s...", num, line);
 489                                 skip = 1;
 490                                 continue;
 491                         }
 492                         num++;
 493                         if (skip) {
 494                                 skip = 0;
 495                                 continue;
 496                         }
 497                         line[i] = '\0';
 498
 499                         /* Skip leading whitespace, empty and comment lines. */
 500                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 501                                 ;
 502                         if (!*cp || *cp == '\n' || *cp == '#')
 503                                 continue ;
 504                         i = strtol(cp, &ep, 10);
 505                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 506                                 int quoted = 0;
 507                                 comment = cp;
 508                                 for (; *cp && (quoted || (*cp != ' ' &&
 509                                     *cp != '\t')); cp++) {
 510                                         if (*cp == '\\' && cp[1] == '"')
 511                                                 cp++;   /* Skip both */
 512                                         else if (*cp == '"')
 513                                                 quoted = !quoted;
 514                                 }
 515                                 if (!*cp)
 516                                         continue;
 517                                 *cp++ = '\0';
 518                         }
 519                         ep = cp;
 520                         public = key_new(KEY_RSA1);
 521                         if (key_read(public, &cp) != 1) {
 522                                 cp = ep;
 523                                 key_free(public);
 524                                 public = key_new(KEY_UNSPEC);
 525                                 if (key_read(public, &cp) != 1) {
 526                                         key_free(public);
 527                                         continue;
 528                                 }
 529                         }
 530                         comment = *cp ? cp : comment;
 531                         fp = key_fingerprint(public, fptype, rep);
 532                         printf("%u %s %s\n", key_size(public), fp,
 533                             comment ? comment : "no comment");
 534                         xfree(fp);
 535                         key_free(public);
 536                         invalid = 0;
 537                 }
 538                 fclose(f);
 539         }
 540         if (invalid) {
 541                 printf("%s is not a public key file.\n", identity_file);
 542                 exit(1);
 543         }
 544         exit(0);
 545 }
 546
 547 /*
 548  * Perform changing a passphrase.  The argument is the passwd structure
 549  * for the current user.
 550  */
 551 static void
 552 do_change_passphrase(struct passwd *pw)
 553 {
 554         char *comment;
 555         char *old_passphrase, *passphrase1, *passphrase2;
 556         struct stat st;
 557         Key *private;
 558
 559         if (!have_identity)
 560                 ask_filename(pw, "Enter file in which the key is");
 561         if (stat(identity_file, &st) < 0) {
 562                 perror(identity_file);
 563                 exit(1);
 564         }
 565         /* Try to load the file with empty passphrase. */
 566         private = key_load_private(identity_file, "", &comment);
 567         if (private == NULL) {
 568                 if (identity_passphrase)
 569                         old_passphrase = xstrdup(identity_passphrase);
 570                 else
 571                         old_passphrase =
 572                             read_passphrase("Enter old passphrase: ",
 573                             RP_ALLOW_STDIN);
 574                 private = key_load_private(identity_file, old_passphrase,
 575                     &comment);
 576                 memset(old_passphrase, 0, strlen(old_passphrase));
 577                 xfree(old_passphrase);
 578                 if (private == NULL) {
 579                         printf("Bad passphrase.\n");
 580                         exit(1);
 581                 }
 582         }
 583         printf("Key has comment '%s'\n", comment);
 584
 585         /* Ask the new passphrase (twice). */
 586         if (identity_new_passphrase) {
 587                 passphrase1 = xstrdup(identity_new_passphrase);
 588                 passphrase2 = NULL;
 589         } else {
 590                 passphrase1 =
 591                         read_passphrase("Enter new passphrase (empty for no "
 592                             "passphrase): ", RP_ALLOW_STDIN);
 593                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 594                     RP_ALLOW_STDIN);
 595
 596                 /* Verify that they are the same. */
 597                 if (strcmp(passphrase1, passphrase2) != 0) {
 598                         memset(passphrase1, 0, strlen(passphrase1));
 599                         memset(passphrase2, 0, strlen(passphrase2));
 600                         xfree(passphrase1);
 601                         xfree(passphrase2);
 602                         printf("Pass phrases do not match.  Try again.\n");
 603                         exit(1);
 604                 }
 605                 /* Destroy the other copy. */
 606                 memset(passphrase2, 0, strlen(passphrase2));
 607                 xfree(passphrase2);
 608         }
 609
 610         /* Save the file using the new passphrase. */
 611         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 612                 printf("Saving the key failed: %s.\n", identity_file);
 613                 memset(passphrase1, 0, strlen(passphrase1));
 614                 xfree(passphrase1);
 615                 key_free(private);
 616                 xfree(comment);
 617                 exit(1);
 618         }
 619         /* Destroy the passphrase and the copy of the key in memory. */
 620         memset(passphrase1, 0, strlen(passphrase1));
 621         xfree(passphrase1);
 622         key_free(private);               /* Destroys contents */
 623         xfree(comment);
 624
 625         printf("Your identification has been saved with the new passphrase.\n");
 626         exit(0);
 627 }
 628
 629 /*
 630  * Print the SSHFP RR.
 631  */
 632 static void
 633 do_print_resource_record(struct passwd *pw, char *hostname)
 634 {
 635         Key *public;
 636         char *comment = NULL;
 637         struct stat st;
 638
 639         if (!have_identity)
 640                 ask_filename(pw, "Enter file in which the key is");
 641         if (stat(identity_file, &st) < 0) {
 642                 perror(identity_file);
 643                 exit(1);
 644         }
 645         public = key_load_public(identity_file, &comment);
 646         if (public != NULL) {
 647                 export_dns_rr(hostname, public, stdout, print_generic);
 648                 key_free(public);
 649                 xfree(comment);
 650                 exit(0);
 651         }
 652         if (comment)
 653                 xfree(comment);
 654
 655         printf("failed to read v2 public key from %s.\n", identity_file);
 656         exit(1);
 657 }
 658
 659 /*
 660  * Change the comment of a private key file.
 661  */
 662 static void
 663 do_change_comment(struct passwd *pw)
 664 {
 665         char new_comment[1024], *comment, *passphrase;
 666         Key *private;
 667         Key *public;
 668         struct stat st;
 669         FILE *f;
 670         int fd;
 671
 672         if (!have_identity)
 673                 ask_filename(pw, "Enter file in which the key is");
 674         if (stat(identity_file, &st) < 0) {
 675                 perror(identity_file);
 676                 exit(1);
 677         }
 678         private = key_load_private(identity_file, "", &comment);
 679         if (private == NULL) {
 680                 if (identity_passphrase)
 681                         passphrase = xstrdup(identity_passphrase);
 682                 else if (identity_new_passphrase)
 683                         passphrase = xstrdup(identity_new_passphrase);
 684                 else
 685                         passphrase = read_passphrase("Enter passphrase: ",
 686                             RP_ALLOW_STDIN);
 687                 /* Try to load using the passphrase. */
 688                 private = key_load_private(identity_file, passphrase, &comment);
 689                 if (private == NULL) {
 690                         memset(passphrase, 0, strlen(passphrase));
 691                         xfree(passphrase);
 692                         printf("Bad passphrase.\n");
 693                         exit(1);
 694                 }
 695         } else {
 696                 passphrase = xstrdup("");
 697         }
 698         if (private->type != KEY_RSA1) {
 699                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 700                 key_free(private);
 701                 exit(1);
 702         }
 703         printf("Key now has comment '%s'\n", comment);
 704
 705         if (identity_comment) {
 706                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 707         } else {
 708                 printf("Enter new comment: ");
 709                 fflush(stdout);
 710                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 711                         memset(passphrase, 0, strlen(passphrase));
 712                         key_free(private);
 713                         exit(1);
 714                 }
 715                 if (strchr(new_comment, '\n'))
 716                         *strchr(new_comment, '\n') = 0;
 717         }
 718
 719         /* Save the file using the new passphrase. */
 720         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 721                 printf("Saving the key failed: %s.\n", identity_file);
 722                 memset(passphrase, 0, strlen(passphrase));
 723                 xfree(passphrase);
 724                 key_free(private);
 725                 xfree(comment);
 726                 exit(1);
 727         }
 728         memset(passphrase, 0, strlen(passphrase));
 729         xfree(passphrase);
 730         public = key_from_private(private);
 731         key_free(private);
 732
 733         strlcat(identity_file, ".pub", sizeof(identity_file));
 734         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 735         if (fd == -1) {
 736                 printf("Could not save your public key in %s\n", identity_file);
 737                 exit(1);
 738         }
 739         f = fdopen(fd, "w");
 740         if (f == NULL) {
 741                 printf("fdopen %s failed", identity_file);
 742                 exit(1);
 743         }
 744         if (!key_write(public, f))
 745                 fprintf(stderr, "write key failed");
 746         key_free(public);
 747         fprintf(f, " %s\n", new_comment);
 748         fclose(f);
 749
 750         xfree(comment);
 751
 752         printf("The comment in your key file has been changed.\n");
 753         exit(0);
 754 }
 755
 756 static void
 757 usage(void)
 758 {
 759         fprintf(stderr, "Usage: %s [options]\n", __progname);
 760         fprintf(stderr, "Options:\n");
 761         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 762         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 763         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 764         fprintf(stderr, "  -f filename Filename of the key file.\n");
 765         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
 766         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 767         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 768         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 769         fprintf(stderr, "  -q          Quiet.\n");
 770         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 771         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 772         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 773         fprintf(stderr, "  -C comment  Provide new comment.\n");
 774         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 775         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 776         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
 777 #ifdef SMARTCARD
 778         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 779         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 780 #endif /* SMARTCARD */
 781
 782         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli\n");
 783         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli\n");
 784
 785         exit(1);
 786 }
 787
 788 /*
 789  * Main program for key management.
 790  */
 791 int
 792 main(int ac, char **av)
 793 {
 794         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 795         char out_file[MAXPATHLEN], *reader_id = NULL;
 796         char *resource_record_hostname = NULL;
 797         Key *private, *public;
 798         struct passwd *pw;
 799         struct stat st;
 800         int opt, type, fd, download = 0, memory = 0;
 801         int generator_wanted = 0, trials = 100;
 802         int do_gen_candidates = 0, do_screen_candidates = 0;
 803         int log_level = SYSLOG_LEVEL_INFO;
 804         BIGNUM *start = NULL;
 805         FILE *f;
 806
 807         extern int optind;
 808         extern char *optarg;
 809
 810         __progname = ssh_get_progname(av[0]);
 811
 812         SSLeay_add_all_algorithms();
 813         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
 814
 815         init_rng();
 816         seed_rng();
 817
 818         /* we need this for the home * directory.  */
 819         pw = getpwuid(getuid());
 820         if (!pw) {
 821                 printf("You don't exist, go away!\n");
 822                 exit(1);
 823         }
 824         if (gethostname(hostname, sizeof(hostname)) < 0) {
 825                 perror("gethostname");
 826                 exit(1);
 827         }
 828
 829         while ((opt = getopt(ac, av,
 830             "degiqpclBRvxXyb:f:t:U:D:P:N:C:r:g:T:G:M:S:a:W:")) != -1) {
 831                 switch (opt) {
 832                 case 'b':
 833                         bits = atoi(optarg);
 834                         if (bits < 512 || bits > 32768) {
 835                                 printf("Bits has bad value.\n");
 836                                 exit(1);
 837                         }
 838                         break;
 839                 case 'l':
 840                         print_fingerprint = 1;
 841                         break;
 842                 case 'B':
 843                         print_bubblebabble = 1;
 844                         break;
 845                 case 'p':
 846                         change_passphrase = 1;
 847                         break;
 848                 case 'c':
 849                         change_comment = 1;
 850                         break;
 851                 case 'f':
 852                         strlcpy(identity_file, optarg, sizeof(identity_file));
 853                         have_identity = 1;
 854                         break;
 855                 case 'g':
 856                         print_generic = 1;
 857                         break;
 858                 case 'P':
 859                         identity_passphrase = optarg;
 860                         break;
 861                 case 'N':
 862                         identity_new_passphrase = optarg;
 863                         break;
 864                 case 'C':
 865                         identity_comment = optarg;
 866                         break;
 867                 case 'q':
 868                         quiet = 1;
 869                         break;
 870                 case 'R':
 871                         /* unused */
 872                         exit(0);
 873                         break;
 874                 case 'e':
 875                 case 'x':
 876                         /* export key */
 877                         convert_to_ssh2 = 1;
 878                         break;
 879                 case 'i':
 880                 case 'X':
 881                         /* import key */
 882                         convert_from_ssh2 = 1;
 883                         break;
 884                 case 'y':
 885                         print_public = 1;
 886                         break;
 887                 case 'd':
 888                         key_type_name = "dsa";
 889                         break;
 890                 case 't':
 891                         key_type_name = optarg;
 892                         break;
 893                 case 'D':
 894                         download = 1;
 895                 case 'U':
 896                         reader_id = optarg;
 897                         break;
 898                 case 'v':
 899                         if (log_level == SYSLOG_LEVEL_INFO)
 900                                 log_level = SYSLOG_LEVEL_DEBUG1;
 901                         else {
 902                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
 903                                     log_level < SYSLOG_LEVEL_DEBUG3)
 904                                         log_level++;
 905                         }
 906                         break;
 907                 case 'r':
 908                         resource_record_hostname = optarg;
 909                         break;
 910                 case 'W':
 911                         generator_wanted = atoi(optarg);
 912                         if (generator_wanted < 1)
 913                                 fatal("Desired generator has bad value.");
 914                         break;
 915                 case 'a':
 916                         trials = atoi(optarg);
 917                         break;
 918                 case 'M':
 919                         memory = atoi(optarg);
 920                         break;
 921                 case 'G':
 922                         do_gen_candidates = 1;
 923                         strlcpy(out_file, optarg, sizeof(out_file));
 924                         break;
 925                 case 'T':
 926                         do_screen_candidates = 1;
 927                         strlcpy(out_file, optarg, sizeof(out_file));
 928                         break;
 929                 case 'S':
 930                         /* XXX - also compare length against bits */
 931                         if (BN_hex2bn(&start, optarg) == 0)
 932                                 fatal("Invalid start point.");
 933                         break;
 934                 case '?':
 935                 default:
 936                         usage();
 937                 }
 938         }
 939
 940         /* reinit */
 941         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
 942
 943         if (optind < ac) {
 944                 printf("Too many arguments.\n");
 945                 usage();
 946         }
 947         if (change_passphrase && change_comment) {
 948                 printf("Can only have one of -p and -c.\n");
 949                 usage();
 950         }
 951         if (print_fingerprint || print_bubblebabble)
 952                 do_fingerprint(pw);
 953         if (change_passphrase)
 954                 do_change_passphrase(pw);
 955         if (change_comment)
 956                 do_change_comment(pw);
 957         if (convert_to_ssh2)
 958                 do_convert_to_ssh2(pw);
 959         if (convert_from_ssh2)
 960                 do_convert_from_ssh2(pw);
 961         if (print_public)
 962                 do_print_public(pw);
 963         if (resource_record_hostname != NULL) {
 964                 do_print_resource_record(pw, resource_record_hostname);
 965         }
 966         if (reader_id != NULL) {
 967 #ifdef SMARTCARD
 968                 if (download)
 969                         do_download(pw, reader_id);
 970                 else
 971                         do_upload(pw, reader_id);
 972 #else /* SMARTCARD */
 973                 fatal("no support for smartcards.");
 974 #endif /* SMARTCARD */
 975         }
 976
 977         if (do_gen_candidates) {
 978                 FILE *out = fopen(out_file, "w");
 979
 980                 if (out == NULL) {
 981                         error("Couldn't open modulus candidate file \"%s\": %s",
 982                             out_file, strerror(errno));
 983                         return (1);
 984                 }
 985                 if (gen_candidates(out, memory, bits, start) != 0)
 986                         fatal("modulus candidate generation failed\n");
 987
 988                 return (0);
 989         }
 990
 991         if (do_screen_candidates) {
 992                 FILE *in;
 993                 FILE *out = fopen(out_file, "w");
 994
 995                 if (have_identity && strcmp(identity_file, "-") != 0) {
 996                         if ((in = fopen(identity_file, "r")) == NULL) {
 997                                 fatal("Couldn't open modulus candidate "
 998                                     "file \"%s\": %s", identity_file,
 999                                     strerror(errno));
1000                         }
1001                 } else
1002                         in = stdin;
1003
1004                 if (out == NULL) {
1005                         fatal("Couldn't open moduli file \"%s\": %s",
1006                             out_file, strerror(errno));
1007                 }
1008                 if (prime_test(in, out, trials, generator_wanted) != 0)
1009                         fatal("modulus screening failed\n");
1010                 return (0);
1011         }
1012
1013         arc4random_stir();
1014
1015         if (key_type_name == NULL) {
1016                 printf("You must specify a key type (-t).\n");
1017                 usage();
1018         }
1019         type = key_type_from_name(key_type_name);
1020         if (type == KEY_UNSPEC) {
1021                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1022                 exit(1);
1023         }
1024         if (!quiet)
1025                 printf("Generating public/private %s key pair.\n", key_type_name);
1026         private = key_generate(type, bits);
1027         if (private == NULL) {
1028                 fprintf(stderr, "key_generate failed");
1029                 exit(1);
1030         }
1031         public  = key_from_private(private);
1032
1033         if (!have_identity)
1034                 ask_filename(pw, "Enter file in which to save the key");
1035
1036         /* Create ~/.ssh directory if it doesn\'t already exist. */
1037         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1038         if (strstr(identity_file, dotsshdir) != NULL &&
1039             stat(dotsshdir, &st) < 0) {
1040                 if (mkdir(dotsshdir, 0700) < 0)
1041                         error("Could not create directory '%s'.", dotsshdir);
1042                 else if (!quiet)
1043                         printf("Created directory '%s'.\n", dotsshdir);
1044         }
1045         /* If the file already exists, ask the user to confirm. */
1046         if (stat(identity_file, &st) >= 0) {
1047                 char yesno[3];
1048                 printf("%s already exists.\n", identity_file);
1049                 printf("Overwrite (y/n)? ");
1050                 fflush(stdout);
1051                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1052                         exit(1);
1053                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1054                         exit(1);
1055         }
1056         /* Ask for a passphrase (twice). */
1057         if (identity_passphrase)
1058                 passphrase1 = xstrdup(identity_passphrase);
1059         else if (identity_new_passphrase)
1060                 passphrase1 = xstrdup(identity_new_passphrase);
1061         else {
1062 passphrase_again:
1063                 passphrase1 =
1064                         read_passphrase("Enter passphrase (empty for no "
1065                             "passphrase): ", RP_ALLOW_STDIN);
1066                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1067                     RP_ALLOW_STDIN);
1068                 if (strcmp(passphrase1, passphrase2) != 0) {
1069                         /*
1070                          * The passphrases do not match.  Clear them and
1071                          * retry.
1072                          */
1073                         memset(passphrase1, 0, strlen(passphrase1));
1074                         memset(passphrase2, 0, strlen(passphrase2));
1075                         xfree(passphrase1);
1076                         xfree(passphrase2);
1077                         printf("Passphrases do not match.  Try again.\n");
1078                         goto passphrase_again;
1079                 }
1080                 /* Clear the other copy of the passphrase. */
1081                 memset(passphrase2, 0, strlen(passphrase2));
1082                 xfree(passphrase2);
1083         }
1084
1085         if (identity_comment) {
1086                 strlcpy(comment, identity_comment, sizeof(comment));
1087         } else {
1088                 /* Create default commend field for the passphrase. */
1089                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1090         }
1091
1092         /* Save the key with the given passphrase and comment. */
1093         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1094                 printf("Saving the key failed: %s.\n", identity_file);
1095                 memset(passphrase1, 0, strlen(passphrase1));
1096                 xfree(passphrase1);
1097                 exit(1);
1098         }
1099         /* Clear the passphrase. */
1100         memset(passphrase1, 0, strlen(passphrase1));
1101         xfree(passphrase1);
1102
1103         /* Clear the private key and the random number generator. */
1104         key_free(private);
1105         arc4random_stir();
1106
1107         if (!quiet)
1108                 printf("Your identification has been saved in %s.\n", identity_file);
1109
1110         strlcat(identity_file, ".pub", sizeof(identity_file));
1111         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1112         if (fd == -1) {
1113                 printf("Could not save your public key in %s\n", identity_file);
1114                 exit(1);
1115         }
1116         f = fdopen(fd, "w");
1117         if (f == NULL) {
1118                 printf("fdopen %s failed", identity_file);
1119                 exit(1);
1120         }
1121         if (!key_write(public, f))
1122                 fprintf(stderr, "write key failed");
1123         fprintf(f, " %s\n", comment);
1124         fclose(f);
1125
1126         if (!quiet) {
1127                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1128                 printf("Your public key has been saved in %s.\n",
1129                     identity_file);
1130                 printf("The key fingerprint is:\n");
1131                 printf("%s %s\n", fp, comment);
1132                 xfree(fp);
1133         }
1134
1135         key_free(public);
1136         exit(0);
1137 }