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 1.107 2003/07/28 09:49:56 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 "readpass.h"
  30 #include "moduli.h"
  31
  32 #ifdef SMARTCARD
  33 #include "scard.h"
  34 #endif
  35 #ifdef DNS
  36 #include "dns.h"
  37 #endif
  38
  39 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  40 int bits = 1024;
  41
  42 /*
  43  * Flag indicating that we just want to change the passphrase.  This can be
  44  * set on the command line.
  45  */
  46 int change_passphrase = 0;
  47
  48 /*
  49  * Flag indicating that we just want to change the comment.  This can be set
  50  * on the command line.
  51  */
  52 int change_comment = 0;
  53
  54 int quiet = 0;
  55
  56 /* Flag indicating that we just want to see the key fingerprint */
  57 int print_fingerprint = 0;
  58 int print_bubblebabble = 0;
  59
  60 /* The identity file name, given on the command line or entered by the user. */
  61 char identity_file[1024];
  62 int have_identity = 0;
  63
  64 /* This is set to the passphrase if given on the command line. */
  65 char *identity_passphrase = NULL;
  66
  67 /* This is set to the new passphrase if given on the command line. */
  68 char *identity_new_passphrase = NULL;
  69
  70 /* This is set to the new comment if given on the command line. */
  71 char *identity_comment = NULL;
  72
  73 /* Dump public key file in format used by real and the original SSH 2 */
  74 int convert_to_ssh2 = 0;
  75 int convert_from_ssh2 = 0;
  76 int print_public = 0;
  77 int print_generic = 0;
  78
  79 char *key_type_name = NULL;
  80
  81 /* argv0 */
  82 #ifdef HAVE___PROGNAME
  83 extern char *__progname;
  84 #else
  85 char *__progname;
  86 #endif
  87
  88 char hostname[MAXHOSTNAMELEN];
  89
  90 static void
  91 ask_filename(struct passwd *pw, const char *prompt)
  92 {
  93         char buf[1024];
  94         char *name = NULL;
  95
  96         if (key_type_name == NULL)
  97                 name = _PATH_SSH_CLIENT_ID_RSA;
  98         else
  99                 switch (key_type_from_name(key_type_name)) {
 100                 case KEY_RSA1:
 101                         name = _PATH_SSH_CLIENT_IDENTITY;
 102                         break;
 103                 case KEY_DSA:
 104                         name = _PATH_SSH_CLIENT_ID_DSA;
 105                         break;
 106                 case KEY_RSA:
 107                         name = _PATH_SSH_CLIENT_ID_RSA;
 108                         break;
 109                 default:
 110                         fprintf(stderr, "bad key type");
 111                         exit(1);
 112                         break;
 113                 }
 114
 115         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 116         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 117         if (fgets(buf, sizeof(buf), stdin) == NULL)
 118                 exit(1);
 119         if (strchr(buf, '\n'))
 120                 *strchr(buf, '\n') = 0;
 121         if (strcmp(buf, "") != 0)
 122                 strlcpy(identity_file, buf, sizeof(identity_file));
 123         have_identity = 1;
 124 }
 125
 126 static Key *
 127 load_identity(char *filename)
 128 {
 129         char *pass;
 130         Key *prv;
 131
 132         prv = key_load_private(filename, "", NULL);
 133         if (prv == NULL) {
 134                 if (identity_passphrase)
 135                         pass = xstrdup(identity_passphrase);
 136                 else
 137                         pass = read_passphrase("Enter passphrase: ",
 138                             RP_ALLOW_STDIN);
 139                 prv = key_load_private(filename, pass, NULL);
 140                 memset(pass, 0, strlen(pass));
 141                 xfree(pass);
 142         }
 143         return prv;
 144 }
 145
 146 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 147 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 148 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 149 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 150
 151 static void
 152 do_convert_to_ssh2(struct passwd *pw)
 153 {
 154         Key *k;
 155         u_int len;
 156         u_char *blob;
 157         struct stat st;
 158
 159         if (!have_identity)
 160                 ask_filename(pw, "Enter file in which the key is");
 161         if (stat(identity_file, &st) < 0) {
 162                 perror(identity_file);
 163                 exit(1);
 164         }
 165         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 166                 if ((k = load_identity(identity_file)) == NULL) {
 167                         fprintf(stderr, "load failed\n");
 168                         exit(1);
 169                 }
 170         }
 171         if (k->type == KEY_RSA1) {
 172                 fprintf(stderr, "version 1 keys are not supported\n");
 173                 exit(1);
 174         }
 175         if (key_to_blob(k, &blob, &len) <= 0) {
 176                 fprintf(stderr, "key_to_blob failed\n");
 177                 exit(1);
 178         }
 179         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 180         fprintf(stdout,
 181             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 182             key_size(k), key_type(k),
 183             pw->pw_name, hostname);
 184         dump_base64(stdout, blob, len);
 185         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 186         key_free(k);
 187         xfree(blob);
 188         exit(0);
 189 }
 190
 191 static void
 192 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 193 {
 194         int bits = buffer_get_int(b);
 195         int bytes = (bits + 7) / 8;
 196
 197         if (buffer_len(b) < bytes)
 198                 fatal("buffer_get_bignum_bits: input buffer too small: "
 199                     "need %d have %d", bytes, buffer_len(b));
 200         BN_bin2bn(buffer_ptr(b), bytes, value);
 201         buffer_consume(b, bytes);
 202 }
 203
 204 static Key *
 205 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 206 {
 207         Buffer b;
 208         Key *key = NULL;
 209         char *type, *cipher;
 210         u_char *sig, data[] = "abcde12345";
 211         int magic, rlen, ktype, i1, i2, i3, i4;
 212         u_int slen;
 213         u_long e;
 214
 215         buffer_init(&b);
 216         buffer_append(&b, blob, blen);
 217
 218         magic  = buffer_get_int(&b);
 219         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 220                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 221                 buffer_free(&b);
 222                 return NULL;
 223         }
 224         i1 = buffer_get_int(&b);
 225         type   = buffer_get_string(&b, NULL);
 226         cipher = buffer_get_string(&b, NULL);
 227         i2 = buffer_get_int(&b);
 228         i3 = buffer_get_int(&b);
 229         i4 = buffer_get_int(&b);
 230         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 231         if (strcmp(cipher, "none") != 0) {
 232                 error("unsupported cipher %s", cipher);
 233                 xfree(cipher);
 234                 buffer_free(&b);
 235                 xfree(type);
 236                 return NULL;
 237         }
 238         xfree(cipher);
 239
 240         if (strstr(type, "dsa")) {
 241                 ktype = KEY_DSA;
 242         } else if (strstr(type, "rsa")) {
 243                 ktype = KEY_RSA;
 244         } else {
 245                 xfree(type);
 246                 return NULL;
 247         }
 248         key = key_new_private(ktype);
 249         xfree(type);
 250
 251         switch (key->type) {
 252         case KEY_DSA:
 253                 buffer_get_bignum_bits(&b, key->dsa->p);
 254                 buffer_get_bignum_bits(&b, key->dsa->g);
 255                 buffer_get_bignum_bits(&b, key->dsa->q);
 256                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 257                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 258                 break;
 259         case KEY_RSA:
 260                 e  = buffer_get_char(&b);
 261                 debug("e %lx", e);
 262                 if (e < 30) {
 263                         e <<= 8;
 264                         e += buffer_get_char(&b);
 265                         debug("e %lx", e);
 266                         e <<= 8;
 267                         e += buffer_get_char(&b);
 268                         debug("e %lx", e);
 269                 }
 270                 if (!BN_set_word(key->rsa->e, e)) {
 271                         buffer_free(&b);
 272                         key_free(key);
 273                         return NULL;
 274                 }
 275                 buffer_get_bignum_bits(&b, key->rsa->d);
 276                 buffer_get_bignum_bits(&b, key->rsa->n);
 277                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 278                 buffer_get_bignum_bits(&b, key->rsa->q);
 279                 buffer_get_bignum_bits(&b, key->rsa->p);
 280                 rsa_generate_additional_parameters(key->rsa);
 281                 break;
 282         }
 283         rlen = buffer_len(&b);
 284         if (rlen != 0)
 285                 error("do_convert_private_ssh2_from_blob: "
 286                     "remaining bytes in key blob %d", rlen);
 287         buffer_free(&b);
 288
 289         /* try the key */
 290         key_sign(key, &sig, &slen, data, sizeof(data));
 291         key_verify(key, sig, slen, data, sizeof(data));
 292         xfree(sig);
 293         return key;
 294 }
 295
 296 static void
 297 do_convert_from_ssh2(struct passwd *pw)
 298 {
 299         Key *k;
 300         int blen;
 301         u_int len;
 302         char line[1024], *p;
 303         u_char blob[8096];
 304         char encoded[8096];
 305         struct stat st;
 306         int escaped = 0, private = 0, ok;
 307         FILE *fp;
 308
 309         if (!have_identity)
 310                 ask_filename(pw, "Enter file in which the key is");
 311         if (stat(identity_file, &st) < 0) {
 312                 perror(identity_file);
 313                 exit(1);
 314         }
 315         fp = fopen(identity_file, "r");
 316         if (fp == NULL) {
 317                 perror(identity_file);
 318                 exit(1);
 319         }
 320         encoded[0] = '\0';
 321         while (fgets(line, sizeof(line), fp)) {
 322                 if (!(p = strchr(line, '\n'))) {
 323                         fprintf(stderr, "input line too long.\n");
 324                         exit(1);
 325                 }
 326                 if (p > line && p[-1] == '\\')
 327                         escaped++;
 328                 if (strncmp(line, "----", 4) == 0 ||
 329                     strstr(line, ": ") != NULL) {
 330                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 331                                 private = 1;
 332                         if (strstr(line, " END ") != NULL) {
 333                                 break;
 334                         }
 335                         /* fprintf(stderr, "ignore: %s", line); */
 336                         continue;
 337                 }
 338                 if (escaped) {
 339                         escaped--;
 340                         /* fprintf(stderr, "escaped: %s", line); */
 341                         continue;
 342                 }
 343                 *p = '\0';
 344                 strlcat(encoded, line, sizeof(encoded));
 345         }
 346         len = strlen(encoded);
 347         if (((len % 4) == 3) &&
 348             (encoded[len-1] == '=') &&
 349             (encoded[len-2] == '=') &&
 350             (encoded[len-3] == '='))
 351                 encoded[len-3] = '\0';
 352         blen = uudecode(encoded, blob, sizeof(blob));
 353         if (blen < 0) {
 354                 fprintf(stderr, "uudecode failed.\n");
 355                 exit(1);
 356         }
 357         k = private ?
 358             do_convert_private_ssh2_from_blob(blob, blen) :
 359             key_from_blob(blob, blen);
 360         if (k == NULL) {
 361                 fprintf(stderr, "decode blob failed.\n");
 362                 exit(1);
 363         }
 364         ok = private ?
 365             (k->type == KEY_DSA ?
 366                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 367                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 368             key_write(k, stdout);
 369         if (!ok) {
 370                 fprintf(stderr, "key write failed");
 371                 exit(1);
 372         }
 373         key_free(k);
 374         if (!private)
 375                 fprintf(stdout, "\n");
 376         fclose(fp);
 377         exit(0);
 378 }
 379
 380 static void
 381 do_print_public(struct passwd *pw)
 382 {
 383         Key *prv;
 384         struct stat st;
 385
 386         if (!have_identity)
 387                 ask_filename(pw, "Enter file in which the key is");
 388         if (stat(identity_file, &st) < 0) {
 389                 perror(identity_file);
 390                 exit(1);
 391         }
 392         prv = load_identity(identity_file);
 393         if (prv == NULL) {
 394                 fprintf(stderr, "load failed\n");
 395                 exit(1);
 396         }
 397         if (!key_write(prv, stdout))
 398                 fprintf(stderr, "key_write failed");
 399         key_free(prv);
 400         fprintf(stdout, "\n");
 401         exit(0);
 402 }
 403
 404 #ifdef SMARTCARD
 405 static void
 406 do_upload(struct passwd *pw, const char *sc_reader_id)
 407 {
 408         Key *prv = NULL;
 409         struct stat st;
 410         int ret;
 411
 412         if (!have_identity)
 413                 ask_filename(pw, "Enter file in which the key is");
 414         if (stat(identity_file, &st) < 0) {
 415                 perror(identity_file);
 416                 exit(1);
 417         }
 418         prv = load_identity(identity_file);
 419         if (prv == NULL) {
 420                 error("load failed");
 421                 exit(1);
 422         }
 423         ret = sc_put_key(prv, sc_reader_id);
 424         key_free(prv);
 425         if (ret < 0)
 426                 exit(1);
 427         logit("loading key done");
 428         exit(0);
 429 }
 430
 431 static void
 432 do_download(struct passwd *pw, const char *sc_reader_id)
 433 {
 434         Key **keys = NULL;
 435         int i;
 436
 437         keys = sc_get_keys(sc_reader_id, NULL);
 438         if (keys == NULL)
 439                 fatal("cannot read public key from smartcard");
 440         for (i = 0; keys[i]; i++) {
 441                 key_write(keys[i], stdout);
 442                 key_free(keys[i]);
 443                 fprintf(stdout, "\n");
 444         }
 445         xfree(keys);
 446         exit(0);
 447 }
 448 #endif /* SMARTCARD */
 449
 450 static void
 451 do_fingerprint(struct passwd *pw)
 452 {
 453         FILE *f;
 454         Key *public;
 455         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 456         int i, skip = 0, num = 1, invalid = 1;
 457         enum fp_rep rep;
 458         enum fp_type fptype;
 459         struct stat st;
 460
 461         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 462         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 463
 464         if (!have_identity)
 465                 ask_filename(pw, "Enter file in which the key is");
 466         if (stat(identity_file, &st) < 0) {
 467                 perror(identity_file);
 468                 exit(1);
 469         }
 470         public = key_load_public(identity_file, &comment);
 471         if (public != NULL) {
 472                 fp = key_fingerprint(public, fptype, rep);
 473                 printf("%u %s %s\n", key_size(public), fp, comment);
 474                 key_free(public);
 475                 xfree(comment);
 476                 xfree(fp);
 477                 exit(0);
 478         }
 479         if (comment)
 480                 xfree(comment);
 481
 482         f = fopen(identity_file, "r");
 483         if (f != NULL) {
 484                 while (fgets(line, sizeof(line), f)) {
 485                         i = strlen(line) - 1;
 486                         if (line[i] != '\n') {
 487                                 error("line %d too long: %.40s...", num, line);
 488                                 skip = 1;
 489                                 continue;
 490                         }
 491                         num++;
 492                         if (skip) {
 493                                 skip = 0;
 494                                 continue;
 495                         }
 496                         line[i] = '\0';
 497
 498                         /* Skip leading whitespace, empty and comment lines. */
 499                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 500                                 ;
 501                         if (!*cp || *cp == '\n' || *cp == '#')
 502                                 continue ;
 503                         i = strtol(cp, &ep, 10);
 504                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 505                                 int quoted = 0;
 506                                 comment = cp;
 507                                 for (; *cp && (quoted || (*cp != ' ' &&
 508                                     *cp != '\t')); cp++) {
 509                                         if (*cp == '\\' && cp[1] == '"')
 510                                                 cp++;   /* Skip both */
 511                                         else if (*cp == '"')
 512                                                 quoted = !quoted;
 513                                 }
 514                                 if (!*cp)
 515                                         continue;
 516                                 *cp++ = '\0';
 517                         }
 518                         ep = cp;
 519                         public = key_new(KEY_RSA1);
 520                         if (key_read(public, &cp) != 1) {
 521                                 cp = ep;
 522                                 key_free(public);
 523                                 public = key_new(KEY_UNSPEC);
 524                                 if (key_read(public, &cp) != 1) {
 525                                         key_free(public);
 526                                         continue;
 527                                 }
 528                         }
 529                         comment = *cp ? cp : comment;
 530                         fp = key_fingerprint(public, fptype, rep);
 531                         printf("%u %s %s\n", key_size(public), fp,
 532                             comment ? comment : "no comment");
 533                         xfree(fp);
 534                         key_free(public);
 535                         invalid = 0;
 536                 }
 537                 fclose(f);
 538         }
 539         if (invalid) {
 540                 printf("%s is not a public key file.\n", identity_file);
 541                 exit(1);
 542         }
 543         exit(0);
 544 }
 545
 546 /*
 547  * Perform changing a passphrase.  The argument is the passwd structure
 548  * for the current user.
 549  */
 550 static void
 551 do_change_passphrase(struct passwd *pw)
 552 {
 553         char *comment;
 554         char *old_passphrase, *passphrase1, *passphrase2;
 555         struct stat st;
 556         Key *private;
 557
 558         if (!have_identity)
 559                 ask_filename(pw, "Enter file in which the key is");
 560         if (stat(identity_file, &st) < 0) {
 561                 perror(identity_file);
 562                 exit(1);
 563         }
 564         /* Try to load the file with empty passphrase. */
 565         private = key_load_private(identity_file, "", &comment);
 566         if (private == NULL) {
 567                 if (identity_passphrase)
 568                         old_passphrase = xstrdup(identity_passphrase);
 569                 else
 570                         old_passphrase =
 571                             read_passphrase("Enter old passphrase: ",
 572                             RP_ALLOW_STDIN);
 573                 private = key_load_private(identity_file, old_passphrase,
 574                     &comment);
 575                 memset(old_passphrase, 0, strlen(old_passphrase));
 576                 xfree(old_passphrase);
 577                 if (private == NULL) {
 578                         printf("Bad passphrase.\n");
 579                         exit(1);
 580                 }
 581         }
 582         printf("Key has comment '%s'\n", comment);
 583
 584         /* Ask the new passphrase (twice). */
 585         if (identity_new_passphrase) {
 586                 passphrase1 = xstrdup(identity_new_passphrase);
 587                 passphrase2 = NULL;
 588         } else {
 589                 passphrase1 =
 590                         read_passphrase("Enter new passphrase (empty for no "
 591                             "passphrase): ", RP_ALLOW_STDIN);
 592                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 593                     RP_ALLOW_STDIN);
 594
 595                 /* Verify that they are the same. */
 596                 if (strcmp(passphrase1, passphrase2) != 0) {
 597                         memset(passphrase1, 0, strlen(passphrase1));
 598                         memset(passphrase2, 0, strlen(passphrase2));
 599                         xfree(passphrase1);
 600                         xfree(passphrase2);
 601                         printf("Pass phrases do not match.  Try again.\n");
 602                         exit(1);
 603                 }
 604                 /* Destroy the other copy. */
 605                 memset(passphrase2, 0, strlen(passphrase2));
 606                 xfree(passphrase2);
 607         }
 608
 609         /* Save the file using the new passphrase. */
 610         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 611                 printf("Saving the key failed: %s.\n", identity_file);
 612                 memset(passphrase1, 0, strlen(passphrase1));
 613                 xfree(passphrase1);
 614                 key_free(private);
 615                 xfree(comment);
 616                 exit(1);
 617         }
 618         /* Destroy the passphrase and the copy of the key in memory. */
 619         memset(passphrase1, 0, strlen(passphrase1));
 620         xfree(passphrase1);
 621         key_free(private);               /* Destroys contents */
 622         xfree(comment);
 623
 624         printf("Your identification has been saved with the new passphrase.\n");
 625         exit(0);
 626 }
 627
 628 #ifdef DNS
 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 #endif /* DNS */
 659
 660 /*
 661  * Change the comment of a private key file.
 662  */
 663 static void
 664 do_change_comment(struct passwd *pw)
 665 {
 666         char new_comment[1024], *comment, *passphrase;
 667         Key *private;
 668         Key *public;
 669         struct stat st;
 670         FILE *f;
 671         int fd;
 672
 673         if (!have_identity)
 674                 ask_filename(pw, "Enter file in which the key is");
 675         if (stat(identity_file, &st) < 0) {
 676                 perror(identity_file);
 677                 exit(1);
 678         }
 679         private = key_load_private(identity_file, "", &comment);
 680         if (private == NULL) {
 681                 if (identity_passphrase)
 682                         passphrase = xstrdup(identity_passphrase);
 683                 else if (identity_new_passphrase)
 684                         passphrase = xstrdup(identity_new_passphrase);
 685                 else
 686                         passphrase = read_passphrase("Enter passphrase: ",
 687                             RP_ALLOW_STDIN);
 688                 /* Try to load using the passphrase. */
 689                 private = key_load_private(identity_file, passphrase, &comment);
 690                 if (private == NULL) {
 691                         memset(passphrase, 0, strlen(passphrase));
 692                         xfree(passphrase);
 693                         printf("Bad passphrase.\n");
 694                         exit(1);
 695                 }
 696         } else {
 697                 passphrase = xstrdup("");
 698         }
 699         if (private->type != KEY_RSA1) {
 700                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 701                 key_free(private);
 702                 exit(1);
 703         }
 704         printf("Key now has comment '%s'\n", comment);
 705
 706         if (identity_comment) {
 707                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 708         } else {
 709                 printf("Enter new comment: ");
 710                 fflush(stdout);
 711                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 712                         memset(passphrase, 0, strlen(passphrase));
 713                         key_free(private);
 714                         exit(1);
 715                 }
 716                 if (strchr(new_comment, '\n'))
 717                         *strchr(new_comment, '\n') = 0;
 718         }
 719
 720         /* Save the file using the new passphrase. */
 721         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 722                 printf("Saving the key failed: %s.\n", identity_file);
 723                 memset(passphrase, 0, strlen(passphrase));
 724                 xfree(passphrase);
 725                 key_free(private);
 726                 xfree(comment);
 727                 exit(1);
 728         }
 729         memset(passphrase, 0, strlen(passphrase));
 730         xfree(passphrase);
 731         public = key_from_private(private);
 732         key_free(private);
 733
 734         strlcat(identity_file, ".pub", sizeof(identity_file));
 735         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 736         if (fd == -1) {
 737                 printf("Could not save your public key in %s\n", identity_file);
 738                 exit(1);
 739         }
 740         f = fdopen(fd, "w");
 741         if (f == NULL) {
 742                 printf("fdopen %s failed", identity_file);
 743                 exit(1);
 744         }
 745         if (!key_write(public, f))
 746                 fprintf(stderr, "write key failed");
 747         key_free(public);
 748         fprintf(f, " %s\n", new_comment);
 749         fclose(f);
 750
 751         xfree(comment);
 752
 753         printf("The comment in your key file has been changed.\n");
 754         exit(0);
 755 }
 756
 757 static void
 758 usage(void)
 759 {
 760         fprintf(stderr, "Usage: %s [options]\n", __progname);
 761         fprintf(stderr, "Options:\n");
 762         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 763         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 764         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 765         fprintf(stderr, "  -f filename Filename of the key file.\n");
 766         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
 767         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 768         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 769         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 770         fprintf(stderr, "  -q          Quiet.\n");
 771         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 772         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 773         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 774         fprintf(stderr, "  -C comment  Provide new comment.\n");
 775         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 776         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 777 #ifdef DNS
 778         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
 779 #endif /* DNS */
 780 #ifdef SMARTCARD
 781         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 782         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 783 #endif /* SMARTCARD */
 784
 785         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli\n");
 786         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli\n");
 787
 788         exit(1);
 789 }
 790
 791 /*
 792  * Main program for key management.
 793  */
 794 int
 795 main(int ac, char **av)
 796 {
 797         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 798         char out_file[PATH_MAX], *reader_id = NULL;
 799         char *resource_record_hostname = NULL;
 800         Key *private, *public;
 801         struct passwd *pw;
 802         struct stat st;
 803         int opt, type, fd, download = 0, memory = 0;
 804         int generator_wanted = 0, trials = 100;
 805         int do_gen_candidates = 0, do_screen_candidates = 0;
 806         BIGNUM *start = NULL;
 807         FILE *f;
 808
 809         extern int optind;
 810         extern char *optarg;
 811
 812         __progname = get_progname(av[0]);
 813
 814         SSLeay_add_all_algorithms();
 815         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
 816
 817         init_rng();
 818         seed_rng();
 819
 820         /* we need this for the home * directory.  */
 821         pw = getpwuid(getuid());
 822         if (!pw) {
 823                 printf("You don't exist, go away!\n");
 824                 exit(1);
 825         }
 826         if (gethostname(hostname, sizeof(hostname)) < 0) {
 827                 perror("gethostname");
 828                 exit(1);
 829         }
 830
 831         while ((opt = getopt(ac, av,
 832             "degiqpclBRxXyb:f:t:U:D:P:N:C:r:g:T:G:M:S:a:W:")) != -1) {
 833                 switch (opt) {
 834                 case 'b':
 835                         bits = atoi(optarg);
 836                         if (bits < 512 || bits > 32768) {
 837                                 printf("Bits has bad value.\n");
 838                                 exit(1);
 839                         }
 840                         break;
 841                 case 'l':
 842                         print_fingerprint = 1;
 843                         break;
 844                 case 'B':
 845                         print_bubblebabble = 1;
 846                         break;
 847                 case 'p':
 848                         change_passphrase = 1;
 849                         break;
 850                 case 'c':
 851                         change_comment = 1;
 852                         break;
 853                 case 'f':
 854                         strlcpy(identity_file, optarg, sizeof(identity_file));
 855                         have_identity = 1;
 856                         break;
 857                 case 'g':
 858                         print_generic = 1;
 859                         break;
 860                 case 'P':
 861                         identity_passphrase = optarg;
 862                         break;
 863                 case 'N':
 864                         identity_new_passphrase = optarg;
 865                         break;
 866                 case 'C':
 867                         identity_comment = optarg;
 868                         break;
 869                 case 'q':
 870                         quiet = 1;
 871                         break;
 872                 case 'R':
 873                         /* unused */
 874                         exit(0);
 875                         break;
 876                 case 'e':
 877                 case 'x':
 878                         /* export key */
 879                         convert_to_ssh2 = 1;
 880                         break;
 881                 case 'i':
 882                 case 'X':
 883                         /* import key */
 884                         convert_from_ssh2 = 1;
 885                         break;
 886                 case 'y':
 887                         print_public = 1;
 888                         break;
 889                 case 'd':
 890                         key_type_name = "dsa";
 891                         break;
 892                 case 't':
 893                         key_type_name = optarg;
 894                         break;
 895                 case 'D':
 896                         download = 1;
 897                 case 'U':
 898                         reader_id = optarg;
 899                         break;
 900                 case 'r':
 901                         resource_record_hostname = optarg;
 902                         break;
 903                 case 'W':
 904                         generator_wanted = atoi(optarg);
 905                         if (generator_wanted < 1)
 906                                 fatal("Desired generator has bad value.");
 907                         break;
 908                 case 'a':
 909                         trials = atoi(optarg);
 910                         if (trials < TRIAL_MINIMUM) {
 911                                 fatal("Minimum primality trials is %d",
 912                                     TRIAL_MINIMUM);
 913                         }
 914                         break;
 915                 case 'M':
 916                         memory = atoi(optarg);
 917                         if (memory != 0 &&
 918                            (memory < LARGE_MINIMUM || memory > LARGE_MAXIMUM)) {
 919                                 fatal("Invalid memory amount (min %ld, max %ld)",
 920                                     LARGE_MINIMUM, LARGE_MAXIMUM);
 921                         }
 922                         break;
 923                 case 'G':
 924                         do_gen_candidates = 1;
 925                         strlcpy(out_file, optarg, sizeof(out_file));
 926                         break;
 927                 case 'T':
 928                         do_screen_candidates = 1;
 929                         strlcpy(out_file, optarg, sizeof(out_file));
 930                         break;
 931                 case 'S':
 932                         /* XXX - also compare length against bits */
 933                         if (BN_hex2bn(&start, optarg) == 0)
 934                                 fatal("Invalid start point.");
 935                         break;
 936                 case '?':
 937                 default:
 938                         usage();
 939                 }
 940         }
 941         if (optind < ac) {
 942                 printf("Too many arguments.\n");
 943                 usage();
 944         }
 945         if (change_passphrase && change_comment) {
 946                 printf("Can only have one of -p and -c.\n");
 947                 usage();
 948         }
 949         if (print_fingerprint || print_bubblebabble)
 950                 do_fingerprint(pw);
 951         if (change_passphrase)
 952                 do_change_passphrase(pw);
 953         if (change_comment)
 954                 do_change_comment(pw);
 955         if (convert_to_ssh2)
 956                 do_convert_to_ssh2(pw);
 957         if (convert_from_ssh2)
 958                 do_convert_from_ssh2(pw);
 959         if (print_public)
 960                 do_print_public(pw);
 961         if (resource_record_hostname != NULL) {
 962 #ifdef DNS
 963                 do_print_resource_record(pw, resource_record_hostname);
 964 #else /* DNS */
 965                 fatal("no DNS support.");
 966 #endif /* DNS */
 967         }
 968         if (reader_id != NULL) {
 969 #ifdef SMARTCARD
 970                 if (download)
 971                         do_download(pw, reader_id);
 972                 else
 973                         do_upload(pw, reader_id);
 974 #else /* SMARTCARD */
 975                 fatal("no support for smartcards.");
 976 #endif /* SMARTCARD */
 977         }
 978
 979         if (do_gen_candidates) {
 980                 FILE *out = fopen(out_file, "w");
 981
 982                 if (out == NULL) {
 983                         error("Couldn't open modulus candidate file \"%s\": %s",
 984                             out_file, strerror(errno));
 985                         return (1);
 986                 }
 987                 if (gen_candidates(out, memory, bits, start) != 0)
 988                         fatal("modulus candidate generation failed\n");
 989
 990                 return (0);
 991         }
 992
 993         if (do_screen_candidates) {
 994                 FILE *in;
 995                 FILE *out = fopen(out_file, "w");
 996
 997                 if (have_identity && strcmp(identity_file, "-") != 0) {
 998                         if ((in = fopen(identity_file, "r")) == NULL) {
 999                                 fatal("Couldn't open modulus candidate "
1000                                     "file \"%s\": %s", identity_file,
1001                                     strerror(errno));
1002                         }
1003                 } else
1004                         in = stdin;
1005
1006                 if (out == NULL) {
1007                         fatal("Couldn't open moduli file \"%s\": %s",
1008                             out_file, strerror(errno));
1009                 }
1010                 if (prime_test(in, out, trials, generator_wanted) != 0)
1011                         fatal("modulus screening failed\n");
1012         }
1013
1014         arc4random_stir();
1015
1016         if (key_type_name == NULL) {
1017                 printf("You must specify a key type (-t).\n");
1018                 usage();
1019         }
1020         type = key_type_from_name(key_type_name);
1021         if (type == KEY_UNSPEC) {
1022                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1023                 exit(1);
1024         }
1025         if (!quiet)
1026                 printf("Generating public/private %s key pair.\n", key_type_name);
1027         private = key_generate(type, bits);
1028         if (private == NULL) {
1029                 fprintf(stderr, "key_generate failed");
1030                 exit(1);
1031         }
1032         public  = key_from_private(private);
1033
1034         if (!have_identity)
1035                 ask_filename(pw, "Enter file in which to save the key");
1036
1037         /* Create ~/.ssh directory if it doesn\'t already exist. */
1038         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1039         if (strstr(identity_file, dotsshdir) != NULL &&
1040             stat(dotsshdir, &st) < 0) {
1041                 if (mkdir(dotsshdir, 0700) < 0)
1042                         error("Could not create directory '%s'.", dotsshdir);
1043                 else if (!quiet)
1044                         printf("Created directory '%s'.\n", dotsshdir);
1045         }
1046         /* If the file already exists, ask the user to confirm. */
1047         if (stat(identity_file, &st) >= 0) {
1048                 char yesno[3];
1049                 printf("%s already exists.\n", identity_file);
1050                 printf("Overwrite (y/n)? ");
1051                 fflush(stdout);
1052                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1053                         exit(1);
1054                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1055                         exit(1);
1056         }
1057         /* Ask for a passphrase (twice). */
1058         if (identity_passphrase)
1059                 passphrase1 = xstrdup(identity_passphrase);
1060         else if (identity_new_passphrase)
1061                 passphrase1 = xstrdup(identity_new_passphrase);
1062         else {
1063 passphrase_again:
1064                 passphrase1 =
1065                         read_passphrase("Enter passphrase (empty for no "
1066                             "passphrase): ", RP_ALLOW_STDIN);
1067                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1068                     RP_ALLOW_STDIN);
1069                 if (strcmp(passphrase1, passphrase2) != 0) {
1070                         /*
1071                          * The passphrases do not match.  Clear them and
1072                          * retry.
1073                          */
1074                         memset(passphrase1, 0, strlen(passphrase1));
1075                         memset(passphrase2, 0, strlen(passphrase2));
1076                         xfree(passphrase1);
1077                         xfree(passphrase2);
1078                         printf("Passphrases do not match.  Try again.\n");
1079                         goto passphrase_again;
1080                 }
1081                 /* Clear the other copy of the passphrase. */
1082                 memset(passphrase2, 0, strlen(passphrase2));
1083                 xfree(passphrase2);
1084         }
1085
1086         if (identity_comment) {
1087                 strlcpy(comment, identity_comment, sizeof(comment));
1088         } else {
1089                 /* Create default commend field for the passphrase. */
1090                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1091         }
1092
1093         /* Save the key with the given passphrase and comment. */
1094         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1095                 printf("Saving the key failed: %s.\n", identity_file);
1096                 memset(passphrase1, 0, strlen(passphrase1));
1097                 xfree(passphrase1);
1098                 exit(1);
1099         }
1100         /* Clear the passphrase. */
1101         memset(passphrase1, 0, strlen(passphrase1));
1102         xfree(passphrase1);
1103
1104         /* Clear the private key and the random number generator. */
1105         key_free(private);
1106         arc4random_stir();
1107
1108         if (!quiet)
1109                 printf("Your identification has been saved in %s.\n", identity_file);
1110
1111         strlcat(identity_file, ".pub", sizeof(identity_file));
1112         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1113         if (fd == -1) {
1114                 printf("Could not save your public key in %s\n", identity_file);
1115                 exit(1);
1116         }
1117         f = fdopen(fd, "w");
1118         if (f == NULL) {
1119                 printf("fdopen %s failed", identity_file);
1120                 exit(1);
1121         }
1122         if (!key_write(public, f))
1123                 fprintf(stderr, "write key failed");
1124         fprintf(f, " %s\n", comment);
1125         fclose(f);
1126
1127         if (!quiet) {
1128                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1129                 printf("Your public key has been saved in %s.\n",
1130                     identity_file);
1131                 printf("The key fingerprint is:\n");
1132                 printf("%s %s\n", fp, comment);
1133                 xfree(fp);
1134         }
1135
1136         key_free(public);
1137         exit(0);
1138 }