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 1.97 2002/03/25 17:34:27 markus Exp $");
  16
  17 #include <openssl/evp.h>
  18 #include <openssl/pem.h>
  19
  20 #include "xmalloc.h"
  21 #include "key.h"
  22 #include "rsa.h"
  23 #include "authfile.h"
  24 #include "uuencode.h"
  25 #include "buffer.h"
  26 #include "bufaux.h"
  27 #include "pathnames.h"
  28 #include "log.h"
  29 #include "readpass.h"
  30
  31 #ifdef SMARTCARD
  32 #include "scard.h"
  33 #endif
  34
  35 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  36 int bits = 1024;
  37
  38 /*
  39  * Flag indicating that we just want to change the passphrase.  This can be
  40  * set on the command line.
  41  */
  42 int change_passphrase = 0;
  43
  44 /*
  45  * Flag indicating that we just want to change the comment.  This can be set
  46  * on the command line.
  47  */
  48 int change_comment = 0;
  49
  50 int quiet = 0;
  51
  52 /* Flag indicating that we just want to see the key fingerprint */
  53 int print_fingerprint = 0;
  54 int print_bubblebabble = 0;
  55
  56 /* The identity file name, given on the command line or entered by the user. */
  57 char identity_file[1024];
  58 int have_identity = 0;
  59
  60 /* This is set to the passphrase if given on the command line. */
  61 char *identity_passphrase = NULL;
  62
  63 /* This is set to the new passphrase if given on the command line. */
  64 char *identity_new_passphrase = NULL;
  65
  66 /* This is set to the new comment if given on the command line. */
  67 char *identity_comment = NULL;
  68
  69 /* Dump public key file in format used by real and the original SSH 2 */
  70 int convert_to_ssh2 = 0;
  71 int convert_from_ssh2 = 0;
  72 int print_public = 0;
  73
  74 char *key_type_name = NULL;
  75
  76 /* argv0 */
  77 #ifdef HAVE___PROGNAME
  78 extern char *__progname;
  79 #else
  80 char *__progname;
  81 #endif
  82
  83 char hostname[MAXHOSTNAMELEN];
  84
  85 static void
  86 ask_filename(struct passwd *pw, const char *prompt)
  87 {
  88         char buf[1024];
  89         char *name = NULL;
  90
  91         if (key_type_name == NULL)
  92                 name = _PATH_SSH_CLIENT_ID_RSA;
  93         else
  94                 switch (key_type_from_name(key_type_name)) {
  95                 case KEY_RSA1:
  96                         name = _PATH_SSH_CLIENT_IDENTITY;
  97                         break;
  98                 case KEY_DSA:
  99                         name = _PATH_SSH_CLIENT_ID_DSA;
 100                         break;
 101                 case KEY_RSA:
 102                         name = _PATH_SSH_CLIENT_ID_RSA;
 103                         break;
 104                 default:
 105                         fprintf(stderr, "bad key type");
 106                         exit(1);
 107                         break;
 108                 }
 109
 110         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 111         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 112         fflush(stderr);
 113         if (fgets(buf, sizeof(buf), stdin) == NULL)
 114                 exit(1);
 115         if (strchr(buf, '\n'))
 116                 *strchr(buf, '\n') = 0;
 117         if (strcmp(buf, "") != 0)
 118                 strlcpy(identity_file, buf, sizeof(identity_file));
 119         have_identity = 1;
 120 }
 121
 122 static Key *
 123 load_identity(char *filename)
 124 {
 125         char *pass;
 126         Key *prv;
 127
 128         prv = key_load_private(filename, "", NULL);
 129         if (prv == NULL) {
 130                 if (identity_passphrase)
 131                         pass = xstrdup(identity_passphrase);
 132                 else
 133                         pass = read_passphrase("Enter passphrase: ",
 134                             RP_ALLOW_STDIN);
 135                 prv = key_load_private(filename, pass, NULL);
 136                 memset(pass, 0, strlen(pass));
 137                 xfree(pass);
 138         }
 139         return prv;
 140 }
 141
 142 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 143 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 144 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 145 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 146
 147 static void
 148 do_convert_to_ssh2(struct passwd *pw)
 149 {
 150         Key *k;
 151         u_int len;
 152         u_char *blob;
 153         struct stat st;
 154
 155         if (!have_identity)
 156                 ask_filename(pw, "Enter file in which the key is");
 157         if (stat(identity_file, &st) < 0) {
 158                 perror(identity_file);
 159                 exit(1);
 160         }
 161         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 162                 if ((k = load_identity(identity_file)) == NULL) {
 163                         fprintf(stderr, "load failed\n");
 164                         exit(1);
 165                 }
 166         }
 167         if (key_to_blob(k, &blob, &len) <= 0) {
 168                 fprintf(stderr, "key_to_blob failed\n");
 169                 exit(1);
 170         }
 171         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 172         fprintf(stdout,
 173             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 174             key_size(k), key_type(k),
 175             pw->pw_name, hostname);
 176         dump_base64(stdout, blob, len);
 177         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 178         key_free(k);
 179         xfree(blob);
 180         exit(0);
 181 }
 182
 183 static void
 184 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 185 {
 186         int bits = buffer_get_int(b);
 187         int bytes = (bits + 7) / 8;
 188
 189         if (buffer_len(b) < bytes)
 190                 fatal("buffer_get_bignum_bits: input buffer too small: "
 191                     "need %d have %d", bytes, buffer_len(b));
 192         BN_bin2bn(buffer_ptr(b), bytes, value);
 193         buffer_consume(b, bytes);
 194 }
 195
 196 static Key *
 197 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 198 {
 199         Buffer b;
 200         Key *key = NULL;
 201         char *type, *cipher;
 202         u_char *sig, data[] = "abcde12345";
 203         int magic, rlen, ktype, i1, i2, i3, i4;
 204         u_int slen;
 205         u_long e;
 206
 207         buffer_init(&b);
 208         buffer_append(&b, blob, blen);
 209
 210         magic  = buffer_get_int(&b);
 211         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 212                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 213                 buffer_free(&b);
 214                 return NULL;
 215         }
 216         i1 = buffer_get_int(&b);
 217         type   = buffer_get_string(&b, NULL);
 218         cipher = buffer_get_string(&b, NULL);
 219         i2 = buffer_get_int(&b);
 220         i3 = buffer_get_int(&b);
 221         i4 = buffer_get_int(&b);
 222         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 223         if (strcmp(cipher, "none") != 0) {
 224                 error("unsupported cipher %s", cipher);
 225                 xfree(cipher);
 226                 buffer_free(&b);
 227                 xfree(type);
 228                 return NULL;
 229         }
 230         xfree(cipher);
 231
 232         if (strstr(type, "dsa")) {
 233                 ktype = KEY_DSA;
 234         } else if (strstr(type, "rsa")) {
 235                 ktype = KEY_RSA;
 236         } else {
 237                 xfree(type);
 238                 return NULL;
 239         }
 240         key = key_new_private(ktype);
 241         xfree(type);
 242
 243         switch (key->type) {
 244         case KEY_DSA:
 245                 buffer_get_bignum_bits(&b, key->dsa->p);
 246                 buffer_get_bignum_bits(&b, key->dsa->g);
 247                 buffer_get_bignum_bits(&b, key->dsa->q);
 248                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 249                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 250                 break;
 251         case KEY_RSA:
 252                 e  = buffer_get_char(&b);
 253                 debug("e %lx", e);
 254                 if (e < 30) {
 255                         e <<= 8;
 256                         e += buffer_get_char(&b);
 257                         debug("e %lx", e);
 258                         e <<= 8;
 259                         e += buffer_get_char(&b);
 260                         debug("e %lx", e);
 261                 }
 262                 if (!BN_set_word(key->rsa->e, e)) {
 263                         buffer_free(&b);
 264                         key_free(key);
 265                         return NULL;
 266                 }
 267                 buffer_get_bignum_bits(&b, key->rsa->d);
 268                 buffer_get_bignum_bits(&b, key->rsa->n);
 269                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 270                 buffer_get_bignum_bits(&b, key->rsa->q);
 271                 buffer_get_bignum_bits(&b, key->rsa->p);
 272                 rsa_generate_additional_parameters(key->rsa);
 273                 break;
 274         }
 275         rlen = buffer_len(&b);
 276         if (rlen != 0)
 277                 error("do_convert_private_ssh2_from_blob: "
 278                     "remaining bytes in key blob %d", rlen);
 279         buffer_free(&b);
 280
 281         /* try the key */
 282         key_sign(key, &sig, &slen, data, sizeof(data));
 283         key_verify(key, sig, slen, data, sizeof(data));
 284         xfree(sig);
 285         return key;
 286 }
 287
 288 static void
 289 do_convert_from_ssh2(struct passwd *pw)
 290 {
 291         Key *k;
 292         int blen;
 293         char line[1024], *p;
 294         u_char blob[8096];
 295         char encoded[8096];
 296         struct stat st;
 297         int escaped = 0, private = 0, ok;
 298         FILE *fp;
 299
 300         if (!have_identity)
 301                 ask_filename(pw, "Enter file in which the key is");
 302         if (stat(identity_file, &st) < 0) {
 303                 perror(identity_file);
 304                 exit(1);
 305         }
 306         fp = fopen(identity_file, "r");
 307         if (fp == NULL) {
 308                 perror(identity_file);
 309                 exit(1);
 310         }
 311         encoded[0] = '\0';
 312         while (fgets(line, sizeof(line), fp)) {
 313                 if (!(p = strchr(line, '\n'))) {
 314                         fprintf(stderr, "input line too long.\n");
 315                         exit(1);
 316                 }
 317                 if (p > line && p[-1] == '\\')
 318                         escaped++;
 319                 if (strncmp(line, "----", 4) == 0 ||
 320                     strstr(line, ": ") != NULL) {
 321                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 322                                 private = 1;
 323                         if (strstr(line, " END ") != NULL) {
 324                                 break;
 325                         }
 326                         /* fprintf(stderr, "ignore: %s", line); */
 327                         continue;
 328                 }
 329                 if (escaped) {
 330                         escaped--;
 331                         /* fprintf(stderr, "escaped: %s", line); */
 332                         continue;
 333                 }
 334                 *p = '\0';
 335                 strlcat(encoded, line, sizeof(encoded));
 336         }
 337         blen = uudecode(encoded, blob, sizeof(blob));
 338         if (blen < 0) {
 339                 fprintf(stderr, "uudecode failed.\n");
 340                 exit(1);
 341         }
 342         k = private ?
 343             do_convert_private_ssh2_from_blob(blob, blen) :
 344             key_from_blob(blob, blen);
 345         if (k == NULL) {
 346                 fprintf(stderr, "decode blob failed.\n");
 347                 exit(1);
 348         }
 349         ok = private ?
 350             (k->type == KEY_DSA ?
 351                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 352                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 353             key_write(k, stdout);
 354         if (!ok) {
 355                 fprintf(stderr, "key write failed");
 356                 exit(1);
 357         }
 358         key_free(k);
 359         if (!private)
 360                 fprintf(stdout, "\n");
 361         fclose(fp);
 362         exit(0);
 363 }
 364
 365 static void
 366 do_print_public(struct passwd *pw)
 367 {
 368         Key *prv;
 369         struct stat st;
 370
 371         if (!have_identity)
 372                 ask_filename(pw, "Enter file in which the key is");
 373         if (stat(identity_file, &st) < 0) {
 374                 perror(identity_file);
 375                 exit(1);
 376         }
 377         prv = load_identity(identity_file);
 378         if (prv == NULL) {
 379                 fprintf(stderr, "load failed\n");
 380                 exit(1);
 381         }
 382         if (!key_write(prv, stdout))
 383                 fprintf(stderr, "key_write failed");
 384         key_free(prv);
 385         fprintf(stdout, "\n");
 386         exit(0);
 387 }
 388
 389 #ifdef SMARTCARD
 390 static void
 391 do_upload(struct passwd *pw, const char *sc_reader_id)
 392 {
 393         Key *prv = NULL;
 394         struct stat st;
 395         int ret;
 396
 397         if (!have_identity)
 398                 ask_filename(pw, "Enter file in which the key is");
 399         if (stat(identity_file, &st) < 0) {
 400                 perror(identity_file);
 401                 exit(1);
 402         }
 403         prv = load_identity(identity_file);
 404         if (prv == NULL) {
 405                 error("load failed");
 406                 exit(1);
 407         }
 408         ret = sc_put_key(prv, sc_reader_id);
 409         key_free(prv);
 410         if (ret < 0)
 411                 exit(1);
 412         log("loading key done");
 413         exit(0);
 414 }
 415
 416 static void
 417 do_download(struct passwd *pw, const char *sc_reader_id)
 418 {
 419         Key **keys = NULL;
 420         int i;
 421
 422         keys = sc_get_keys(sc_reader_id, NULL);
 423         if (keys == NULL)
 424                 fatal("cannot read public key from smartcard");
 425         for (i = 0; keys[i]; i++) {
 426                 key_write(keys[i], stdout);
 427                 key_free(keys[i]);
 428                 fprintf(stdout, "\n");
 429         }
 430         xfree(keys);
 431         exit(0);
 432 }
 433 #endif /* SMARTCARD */
 434
 435 static void
 436 do_fingerprint(struct passwd *pw)
 437 {
 438         FILE *f;
 439         Key *public;
 440         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 441         int i, skip = 0, num = 1, invalid = 1;
 442         enum fp_rep rep;
 443         enum fp_type fptype;
 444         struct stat st;
 445
 446         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 447         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 448
 449         if (!have_identity)
 450                 ask_filename(pw, "Enter file in which the key is");
 451         if (stat(identity_file, &st) < 0) {
 452                 perror(identity_file);
 453                 exit(1);
 454         }
 455         public = key_load_public(identity_file, &comment);
 456         if (public != NULL) {
 457                 fp = key_fingerprint(public, fptype, rep);
 458                 printf("%d %s %s\n", key_size(public), fp, comment);
 459                 key_free(public);
 460                 xfree(comment);
 461                 xfree(fp);
 462                 exit(0);
 463         }
 464         if (comment)
 465                 xfree(comment);
 466
 467         f = fopen(identity_file, "r");
 468         if (f != NULL) {
 469                 while (fgets(line, sizeof(line), f)) {
 470                         i = strlen(line) - 1;
 471                         if (line[i] != '\n') {
 472                                 error("line %d too long: %.40s...", num, line);
 473                                 skip = 1;
 474                                 continue;
 475                         }
 476                         num++;
 477                         if (skip) {
 478                                 skip = 0;
 479                                 continue;
 480                         }
 481                         line[i] = '\0';
 482
 483                         /* Skip leading whitespace, empty and comment lines. */
 484                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 485                                 ;
 486                         if (!*cp || *cp == '\n' || *cp == '#')
 487                                 continue ;
 488                         i = strtol(cp, &ep, 10);
 489                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 490                                 int quoted = 0;
 491                                 comment = cp;
 492                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 493                                         if (*cp == '\\' && cp[1] == '"')
 494                                                 cp++;   /* Skip both */
 495                                         else if (*cp == '"')
 496                                                 quoted = !quoted;
 497                                 }
 498                                 if (!*cp)
 499                                         continue;
 500                                 *cp++ = '\0';
 501                         }
 502                         ep = cp;
 503                         public = key_new(KEY_RSA1);
 504                         if (key_read(public, &cp) != 1) {
 505                                 cp = ep;
 506                                 key_free(public);
 507                                 public = key_new(KEY_UNSPEC);
 508                                 if (key_read(public, &cp) != 1) {
 509                                         key_free(public);
 510                                         continue;
 511                                 }
 512                         }
 513                         comment = *cp ? cp : comment;
 514                         fp = key_fingerprint(public, fptype, rep);
 515                         printf("%d %s %s\n", key_size(public), fp,
 516                             comment ? comment : "no comment");
 517                         xfree(fp);
 518                         key_free(public);
 519                         invalid = 0;
 520                 }
 521                 fclose(f);
 522         }
 523         if (invalid) {
 524                 printf("%s is not a public key file.\n", identity_file);
 525                 exit(1);
 526         }
 527         exit(0);
 528 }
 529
 530 /*
 531  * Perform changing a passphrase.  The argument is the passwd structure
 532  * for the current user.
 533  */
 534 static void
 535 do_change_passphrase(struct passwd *pw)
 536 {
 537         char *comment;
 538         char *old_passphrase, *passphrase1, *passphrase2;
 539         struct stat st;
 540         Key *private;
 541
 542         if (!have_identity)
 543                 ask_filename(pw, "Enter file in which the key is");
 544         if (stat(identity_file, &st) < 0) {
 545                 perror(identity_file);
 546                 exit(1);
 547         }
 548         /* Try to load the file with empty passphrase. */
 549         private = key_load_private(identity_file, "", &comment);
 550         if (private == NULL) {
 551                 if (identity_passphrase)
 552                         old_passphrase = xstrdup(identity_passphrase);
 553                 else
 554                         old_passphrase =
 555                             read_passphrase("Enter old passphrase: ",
 556                             RP_ALLOW_STDIN);
 557                 private = key_load_private(identity_file, old_passphrase,
 558                     &comment);
 559                 memset(old_passphrase, 0, strlen(old_passphrase));
 560                 xfree(old_passphrase);
 561                 if (private == NULL) {
 562                         printf("Bad passphrase.\n");
 563                         exit(1);
 564                 }
 565         }
 566         printf("Key has comment '%s'\n", comment);
 567
 568         /* Ask the new passphrase (twice). */
 569         if (identity_new_passphrase) {
 570                 passphrase1 = xstrdup(identity_new_passphrase);
 571                 passphrase2 = NULL;
 572         } else {
 573                 passphrase1 =
 574                         read_passphrase("Enter new passphrase (empty for no "
 575                             "passphrase): ", RP_ALLOW_STDIN);
 576                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 577                     RP_ALLOW_STDIN);
 578
 579                 /* Verify that they are the same. */
 580                 if (strcmp(passphrase1, passphrase2) != 0) {
 581                         memset(passphrase1, 0, strlen(passphrase1));
 582                         memset(passphrase2, 0, strlen(passphrase2));
 583                         xfree(passphrase1);
 584                         xfree(passphrase2);
 585                         printf("Pass phrases do not match.  Try again.\n");
 586                         exit(1);
 587                 }
 588                 /* Destroy the other copy. */
 589                 memset(passphrase2, 0, strlen(passphrase2));
 590                 xfree(passphrase2);
 591         }
 592
 593         /* Save the file using the new passphrase. */
 594         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 595                 printf("Saving the key failed: %s.\n", identity_file);
 596                 memset(passphrase1, 0, strlen(passphrase1));
 597                 xfree(passphrase1);
 598                 key_free(private);
 599                 xfree(comment);
 600                 exit(1);
 601         }
 602         /* Destroy the passphrase and the copy of the key in memory. */
 603         memset(passphrase1, 0, strlen(passphrase1));
 604         xfree(passphrase1);
 605         key_free(private);               /* Destroys contents */
 606         xfree(comment);
 607
 608         printf("Your identification has been saved with the new passphrase.\n");
 609         exit(0);
 610 }
 611
 612 /*
 613  * Change the comment of a private key file.
 614  */
 615 static void
 616 do_change_comment(struct passwd *pw)
 617 {
 618         char new_comment[1024], *comment, *passphrase;
 619         Key *private;
 620         Key *public;
 621         struct stat st;
 622         FILE *f;
 623         int fd;
 624
 625         if (!have_identity)
 626                 ask_filename(pw, "Enter file in which the key is");
 627         if (stat(identity_file, &st) < 0) {
 628                 perror(identity_file);
 629                 exit(1);
 630         }
 631         private = key_load_private(identity_file, "", &comment);
 632         if (private == NULL) {
 633                 if (identity_passphrase)
 634                         passphrase = xstrdup(identity_passphrase);
 635                 else if (identity_new_passphrase)
 636                         passphrase = xstrdup(identity_new_passphrase);
 637                 else
 638                         passphrase = read_passphrase("Enter passphrase: ",
 639                             RP_ALLOW_STDIN);
 640                 /* Try to load using the passphrase. */
 641                 private = key_load_private(identity_file, passphrase, &comment);
 642                 if (private == NULL) {
 643                         memset(passphrase, 0, strlen(passphrase));
 644                         xfree(passphrase);
 645                         printf("Bad passphrase.\n");
 646                         exit(1);
 647                 }
 648         } else {
 649                 passphrase = xstrdup("");
 650         }
 651         if (private->type != KEY_RSA1) {
 652                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 653                 key_free(private);
 654                 exit(1);
 655         }
 656         printf("Key now has comment '%s'\n", comment);
 657
 658         if (identity_comment) {
 659                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 660         } else {
 661                 printf("Enter new comment: ");
 662                 fflush(stdout);
 663                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 664                         memset(passphrase, 0, strlen(passphrase));
 665                         key_free(private);
 666                         exit(1);
 667                 }
 668                 if (strchr(new_comment, '\n'))
 669                         *strchr(new_comment, '\n') = 0;
 670         }
 671
 672         /* Save the file using the new passphrase. */
 673         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 674                 printf("Saving the key failed: %s.\n", identity_file);
 675                 memset(passphrase, 0, strlen(passphrase));
 676                 xfree(passphrase);
 677                 key_free(private);
 678                 xfree(comment);
 679                 exit(1);
 680         }
 681         memset(passphrase, 0, strlen(passphrase));
 682         xfree(passphrase);
 683         public = key_from_private(private);
 684         key_free(private);
 685
 686         strlcat(identity_file, ".pub", sizeof(identity_file));
 687         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 688         if (fd == -1) {
 689                 printf("Could not save your public key in %s\n", identity_file);
 690                 exit(1);
 691         }
 692         f = fdopen(fd, "w");
 693         if (f == NULL) {
 694                 printf("fdopen %s failed", identity_file);
 695                 exit(1);
 696         }
 697         if (!key_write(public, f))
 698                 fprintf(stderr, "write key failed");
 699         key_free(public);
 700         fprintf(f, " %s\n", new_comment);
 701         fclose(f);
 702
 703         xfree(comment);
 704
 705         printf("The comment in your key file has been changed.\n");
 706         exit(0);
 707 }
 708
 709 static void
 710 usage(void)
 711 {
 712         fprintf(stderr, "Usage: %s [options]\n", __progname);
 713         fprintf(stderr, "Options:\n");
 714         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 715         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
 716         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
 717         fprintf(stderr, "  -f filename Filename of the key file.\n");
 718         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
 719         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
 720         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
 721         fprintf(stderr, "  -q          Quiet.\n");
 722         fprintf(stderr, "  -y          Read private key file and print public key.\n");
 723         fprintf(stderr, "  -t type     Specify type of key to create.\n");
 724         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 725         fprintf(stderr, "  -C comment  Provide new comment.\n");
 726         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
 727         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
 728 #ifdef SMARTCARD
 729         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
 730         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
 731 #endif /* SMARTCARD */
 732
 733         exit(1);
 734 }
 735
 736 /*
 737  * Main program for key management.
 738  */
 739 int
 740 main(int ac, char **av)
 741 {
 742         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
 743         char *reader_id = NULL;
 744         Key *private, *public;
 745         struct passwd *pw;
 746         struct stat st;
 747         int opt, type, fd, download = 0;
 748         FILE *f;
 749
 750         extern int optind;
 751         extern char *optarg;
 752
 753         __progname = get_progname(av[0]);
 754
 755         SSLeay_add_all_algorithms();
 756
 757         /* we need this for the home * directory.  */
 758         pw = getpwuid(getuid());
 759         if (!pw) {
 760                 printf("You don't exist, go away!\n");
 761                 exit(1);
 762         }
 763         if (gethostname(hostname, sizeof(hostname)) < 0) {
 764                 perror("gethostname");
 765                 exit(1);
 766         }
 767
 768         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:U:D:P:N:C:")) != -1) {
 769                 switch (opt) {
 770                 case 'b':
 771                         bits = atoi(optarg);
 772                         if (bits < 512 || bits > 32768) {
 773                                 printf("Bits has bad value.\n");
 774                                 exit(1);
 775                         }
 776                         break;
 777                 case 'l':
 778                         print_fingerprint = 1;
 779                         break;
 780                 case 'B':
 781                         print_bubblebabble = 1;
 782                         break;
 783                 case 'p':
 784                         change_passphrase = 1;
 785                         break;
 786                 case 'c':
 787                         change_comment = 1;
 788                         break;
 789                 case 'f':
 790                         strlcpy(identity_file, optarg, sizeof(identity_file));
 791                         have_identity = 1;
 792                         break;
 793                 case 'P':
 794                         identity_passphrase = optarg;
 795                         break;
 796                 case 'N':
 797                         identity_new_passphrase = optarg;
 798                         break;
 799                 case 'C':
 800                         identity_comment = optarg;
 801                         break;
 802                 case 'q':
 803                         quiet = 1;
 804                         break;
 805                 case 'R':
 806                         /* unused */
 807                         exit(0);
 808                         break;
 809                 case 'e':
 810                 case 'x':
 811                         /* export key */
 812                         convert_to_ssh2 = 1;
 813                         break;
 814                 case 'i':
 815                 case 'X':
 816                         /* import key */
 817                         convert_from_ssh2 = 1;
 818                         break;
 819                 case 'y':
 820                         print_public = 1;
 821                         break;
 822                 case 'd':
 823                         key_type_name = "dsa";
 824                         break;
 825                 case 't':
 826                         key_type_name = optarg;
 827                         break;
 828                 case 'D':
 829                         download = 1;
 830                 case 'U':
 831                         reader_id = optarg;
 832                         break;
 833                 case '?':
 834                 default:
 835                         usage();
 836                 }
 837         }
 838         if (optind < ac) {
 839                 printf("Too many arguments.\n");
 840                 usage();
 841         }
 842         if (change_passphrase && change_comment) {
 843                 printf("Can only have one of -p and -c.\n");
 844                 usage();
 845         }
 846         if (print_fingerprint || print_bubblebabble)
 847                 do_fingerprint(pw);
 848         if (change_passphrase)
 849                 do_change_passphrase(pw);
 850         if (convert_to_ssh2)
 851                 do_convert_to_ssh2(pw);
 852         if (change_comment)
 853                 do_change_comment(pw);
 854         if (print_public)
 855                 do_print_public(pw);
 856         if (reader_id != NULL) {
 857 #ifdef SMARTCARD
 858                 if (download)
 859                         do_download(pw, reader_id);
 860                 else
 861                         do_upload(pw, reader_id);
 862 #else /* SMARTCARD */
 863                 fatal("no support for smartcards.");
 864 #endif /* SMARTCARD */
 865         }
 866
 867         init_rng();
 868         seed_rng();
 869         arc4random_stir();
 870
 871         if (convert_from_ssh2)
 872                 do_convert_from_ssh2(pw);
 873
 874         if (key_type_name == NULL) {
 875                 printf("You must specify a key type (-t).\n");
 876                 usage();
 877         }
 878         type = key_type_from_name(key_type_name);
 879         if (type == KEY_UNSPEC) {
 880                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 881                 exit(1);
 882         }
 883         if (!quiet)
 884                 printf("Generating public/private %s key pair.\n", key_type_name);
 885         private = key_generate(type, bits);
 886         if (private == NULL) {
 887                 fprintf(stderr, "key_generate failed");
 888                 exit(1);
 889         }
 890         public  = key_from_private(private);
 891
 892         if (!have_identity)
 893                 ask_filename(pw, "Enter file in which to save the key");
 894
 895         /* Create ~/.ssh directory if it doesn\'t already exist. */
 896         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 897         if (strstr(identity_file, dotsshdir) != NULL &&
 898             stat(dotsshdir, &st) < 0) {
 899                 if (mkdir(dotsshdir, 0700) < 0)
 900                         error("Could not create directory '%s'.", dotsshdir);
 901                 else if (!quiet)
 902                         printf("Created directory '%s'.\n", dotsshdir);
 903         }
 904         /* If the file already exists, ask the user to confirm. */
 905         if (stat(identity_file, &st) >= 0) {
 906                 char yesno[3];
 907                 printf("%s already exists.\n", identity_file);
 908                 printf("Overwrite (y/n)? ");
 909                 fflush(stdout);
 910                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 911                         exit(1);
 912                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 913                         exit(1);
 914         }
 915         /* Ask for a passphrase (twice). */
 916         if (identity_passphrase)
 917                 passphrase1 = xstrdup(identity_passphrase);
 918         else if (identity_new_passphrase)
 919                 passphrase1 = xstrdup(identity_new_passphrase);
 920         else {
 921 passphrase_again:
 922                 passphrase1 =
 923                         read_passphrase("Enter passphrase (empty for no "
 924                             "passphrase): ", RP_ALLOW_STDIN);
 925                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 926                     RP_ALLOW_STDIN);
 927                 if (strcmp(passphrase1, passphrase2) != 0) {
 928                         /*
 929                          * The passphrases do not match.  Clear them and
 930                          * retry.
 931                          */
 932                         memset(passphrase1, 0, strlen(passphrase1));
 933                         memset(passphrase2, 0, strlen(passphrase2));
 934                         xfree(passphrase1);
 935                         xfree(passphrase2);
 936                         printf("Passphrases do not match.  Try again.\n");
 937                         goto passphrase_again;
 938                 }
 939                 /* Clear the other copy of the passphrase. */
 940                 memset(passphrase2, 0, strlen(passphrase2));
 941                 xfree(passphrase2);
 942         }
 943
 944         if (identity_comment) {
 945                 strlcpy(comment, identity_comment, sizeof(comment));
 946         } else {
 947                 /* Create default commend field for the passphrase. */
 948                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 949         }
 950
 951         /* Save the key with the given passphrase and comment. */
 952         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 953                 printf("Saving the key failed: %s.\n", identity_file);
 954                 memset(passphrase1, 0, strlen(passphrase1));
 955                 xfree(passphrase1);
 956                 exit(1);
 957         }
 958         /* Clear the passphrase. */
 959         memset(passphrase1, 0, strlen(passphrase1));
 960         xfree(passphrase1);
 961
 962         /* Clear the private key and the random number generator. */
 963         key_free(private);
 964         arc4random_stir();
 965
 966         if (!quiet)
 967                 printf("Your identification has been saved in %s.\n", identity_file);
 968
 969         strlcat(identity_file, ".pub", sizeof(identity_file));
 970         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 971         if (fd == -1) {
 972                 printf("Could not save your public key in %s\n", identity_file);
 973                 exit(1);
 974         }
 975         f = fdopen(fd, "w");
 976         if (f == NULL) {
 977                 printf("fdopen %s failed", identity_file);
 978                 exit(1);
 979         }
 980         if (!key_write(public, f))
 981                 fprintf(stderr, "write key failed");
 982         fprintf(f, " %s\n", comment);
 983         fclose(f);
 984
 985         if (!quiet) {
 986                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 987                 printf("Your public key has been saved in %s.\n",
 988                     identity_file);
 989                 printf("The key fingerprint is:\n");
 990                 printf("%s %s\n", fp, comment);
 991                 xfree(fp);
 992         }
 993
 994         key_free(public);
 995         exit(0);
 996 }