ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.147 2006/07/09 15:15:11 stevesk Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Identity and host key generation and maintenance.
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  */
  14
  15 #include "includes.h"
  16
  17 #include <sys/types.h>
  18 #include <sys/socket.h>
  19 #include <sys/stat.h>
  20
  21 #include <openssl/evp.h>
  22 #include <openssl/pem.h>
  23
  24 #include <fcntl.h>
  25 #include <paths.h>
  26 #include <pwd.h>
  27
  28 #include "xmalloc.h"
  29 #include "key.h"
  30 #include "rsa.h"
  31 #include "authfile.h"
  32 #include "uuencode.h"
  33 #include "buffer.h"
  34 #include "bufaux.h"
  35 #include "pathnames.h"
  36 #include "log.h"
  37 #include "misc.h"
  38 #include "match.h"
  39 #include "hostfile.h"
  40 #include "dns.h"
  41
  42 #ifdef SMARTCARD
  43 #include "scard.h"
  44 #endif
  45
  46 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  47 #define DEFAULT_BITS            2048
  48 #define DEFAULT_BITS_DSA        1024
  49 u_int32_t bits = 0;
  50
  51 /*
  52  * Flag indicating that we just want to change the passphrase.  This can be
  53  * set on the command line.
  54  */
  55 int change_passphrase = 0;
  56
  57 /*
  58  * Flag indicating that we just want to change the comment.  This can be set
  59  * on the command line.
  60  */
  61 int change_comment = 0;
  62
  63 int quiet = 0;
  64
  65 /* Flag indicating that we want to hash a known_hosts file */
  66 int hash_hosts = 0;
  67 /* Flag indicating that we want lookup a host in known_hosts file */
  68 int find_host = 0;
  69 /* Flag indicating that we want to delete a host from a known_hosts file */
  70 int delete_host = 0;
  71
  72 /* Flag indicating that we just want to see the key fingerprint */
  73 int print_fingerprint = 0;
  74 int print_bubblebabble = 0;
  75
  76 /* The identity file name, given on the command line or entered by the user. */
  77 char identity_file[1024];
  78 int have_identity = 0;
  79
  80 /* This is set to the passphrase if given on the command line. */
  81 char *identity_passphrase = NULL;
  82
  83 /* This is set to the new passphrase if given on the command line. */
  84 char *identity_new_passphrase = NULL;
  85
  86 /* This is set to the new comment if given on the command line. */
  87 char *identity_comment = NULL;
  88
  89 /* Dump public key file in format used by real and the original SSH 2 */
  90 int convert_to_ssh2 = 0;
  91 int convert_from_ssh2 = 0;
  92 int print_public = 0;
  93 int print_generic = 0;
  94
  95 char *key_type_name = NULL;
  96
  97 /* argv0 */
  98 extern char *__progname;
  99
 100 char hostname[MAXHOSTNAMELEN];
 101
 102 /* moduli.c */
 103 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 104 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 105
 106 static void
 107 ask_filename(struct passwd *pw, const char *prompt)
 108 {
 109         char buf[1024];
 110         char *name = NULL;
 111
 112         if (key_type_name == NULL)
 113                 name = _PATH_SSH_CLIENT_ID_RSA;
 114         else {
 115                 switch (key_type_from_name(key_type_name)) {
 116                 case KEY_RSA1:
 117                         name = _PATH_SSH_CLIENT_IDENTITY;
 118                         break;
 119                 case KEY_DSA:
 120                         name = _PATH_SSH_CLIENT_ID_DSA;
 121                         break;
 122                 case KEY_RSA:
 123                         name = _PATH_SSH_CLIENT_ID_RSA;
 124                         break;
 125                 default:
 126                         fprintf(stderr, "bad key type");
 127                         exit(1);
 128                         break;
 129                 }
 130         }
 131         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 132         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 133         if (fgets(buf, sizeof(buf), stdin) == NULL)
 134                 exit(1);
 135         if (strchr(buf, '\n'))
 136                 *strchr(buf, '\n') = 0;
 137         if (strcmp(buf, "") != 0)
 138                 strlcpy(identity_file, buf, sizeof(identity_file));
 139         have_identity = 1;
 140 }
 141
 142 static Key *
 143 load_identity(char *filename)
 144 {
 145         char *pass;
 146         Key *prv;
 147
 148         prv = key_load_private(filename, "", NULL);
 149         if (prv == NULL) {
 150                 if (identity_passphrase)
 151                         pass = xstrdup(identity_passphrase);
 152                 else
 153                         pass = read_passphrase("Enter passphrase: ",
 154                             RP_ALLOW_STDIN);
 155                 prv = key_load_private(filename, pass, NULL);
 156                 memset(pass, 0, strlen(pass));
 157                 xfree(pass);
 158         }
 159         return prv;
 160 }
 161
 162 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 163 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 164 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 165 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 166
 167 static void
 168 do_convert_to_ssh2(struct passwd *pw)
 169 {
 170         Key *k;
 171         u_int len;
 172         u_char *blob;
 173         struct stat st;
 174
 175         if (!have_identity)
 176                 ask_filename(pw, "Enter file in which the key is");
 177         if (stat(identity_file, &st) < 0) {
 178                 perror(identity_file);
 179                 exit(1);
 180         }
 181         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 182                 if ((k = load_identity(identity_file)) == NULL) {
 183                         fprintf(stderr, "load failed\n");
 184                         exit(1);
 185                 }
 186         }
 187         if (k->type == KEY_RSA1) {
 188                 fprintf(stderr, "version 1 keys are not supported\n");
 189                 exit(1);
 190         }
 191         if (key_to_blob(k, &blob, &len) <= 0) {
 192                 fprintf(stderr, "key_to_blob failed\n");
 193                 exit(1);
 194         }
 195         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 196         fprintf(stdout,
 197             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 198             key_size(k), key_type(k),
 199             pw->pw_name, hostname);
 200         dump_base64(stdout, blob, len);
 201         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 202         key_free(k);
 203         xfree(blob);
 204         exit(0);
 205 }
 206
 207 static void
 208 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 209 {
 210         u_int bignum_bits = buffer_get_int(b);
 211         u_int bytes = (bignum_bits + 7) / 8;
 212
 213         if (buffer_len(b) < bytes)
 214                 fatal("buffer_get_bignum_bits: input buffer too small: "
 215                     "need %d have %d", bytes, buffer_len(b));
 216         BN_bin2bn(buffer_ptr(b), bytes, value);
 217         buffer_consume(b, bytes);
 218 }
 219
 220 static Key *
 221 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 222 {
 223         Buffer b;
 224         Key *key = NULL;
 225         char *type, *cipher;
 226         u_char *sig, data[] = "abcde12345";
 227         int magic, rlen, ktype, i1, i2, i3, i4;
 228         u_int slen;
 229         u_long e;
 230
 231         buffer_init(&b);
 232         buffer_append(&b, blob, blen);
 233
 234         magic  = buffer_get_int(&b);
 235         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 236                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 237                 buffer_free(&b);
 238                 return NULL;
 239         }
 240         i1 = buffer_get_int(&b);
 241         type   = buffer_get_string(&b, NULL);
 242         cipher = buffer_get_string(&b, NULL);
 243         i2 = buffer_get_int(&b);
 244         i3 = buffer_get_int(&b);
 245         i4 = buffer_get_int(&b);
 246         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 247         if (strcmp(cipher, "none") != 0) {
 248                 error("unsupported cipher %s", cipher);
 249                 xfree(cipher);
 250                 buffer_free(&b);
 251                 xfree(type);
 252                 return NULL;
 253         }
 254         xfree(cipher);
 255
 256         if (strstr(type, "dsa")) {
 257                 ktype = KEY_DSA;
 258         } else if (strstr(type, "rsa")) {
 259                 ktype = KEY_RSA;
 260         } else {
 261                 buffer_free(&b);
 262                 xfree(type);
 263                 return NULL;
 264         }
 265         key = key_new_private(ktype);
 266         xfree(type);
 267
 268         switch (key->type) {
 269         case KEY_DSA:
 270                 buffer_get_bignum_bits(&b, key->dsa->p);
 271                 buffer_get_bignum_bits(&b, key->dsa->g);
 272                 buffer_get_bignum_bits(&b, key->dsa->q);
 273                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 274                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 275                 break;
 276         case KEY_RSA:
 277                 e  = buffer_get_char(&b);
 278                 debug("e %lx", e);
 279                 if (e < 30) {
 280                         e <<= 8;
 281                         e += buffer_get_char(&b);
 282                         debug("e %lx", e);
 283                         e <<= 8;
 284                         e += buffer_get_char(&b);
 285                         debug("e %lx", e);
 286                 }
 287                 if (!BN_set_word(key->rsa->e, e)) {
 288                         buffer_free(&b);
 289                         key_free(key);
 290                         return NULL;
 291                 }
 292                 buffer_get_bignum_bits(&b, key->rsa->d);
 293                 buffer_get_bignum_bits(&b, key->rsa->n);
 294                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 295                 buffer_get_bignum_bits(&b, key->rsa->q);
 296                 buffer_get_bignum_bits(&b, key->rsa->p);
 297                 rsa_generate_additional_parameters(key->rsa);
 298                 break;
 299         }
 300         rlen = buffer_len(&b);
 301         if (rlen != 0)
 302                 error("do_convert_private_ssh2_from_blob: "
 303                     "remaining bytes in key blob %d", rlen);
 304         buffer_free(&b);
 305
 306         /* try the key */
 307         key_sign(key, &sig, &slen, data, sizeof(data));
 308         key_verify(key, sig, slen, data, sizeof(data));
 309         xfree(sig);
 310         return key;
 311 }
 312
 313 static int
 314 get_line(FILE *fp, char *line, size_t len)
 315 {
 316         int c;
 317         size_t pos = 0;
 318
 319         line[0] = '\0';
 320         while ((c = fgetc(fp)) != EOF) {
 321                 if (pos >= len - 1) {
 322                         fprintf(stderr, "input line too long.\n");
 323                         exit(1);
 324                 }
 325                 switch (c) {
 326                 case '\r':
 327                         c = fgetc(fp);
 328                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 329                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 330                                 exit(1);
 331                         }
 332                         return pos;
 333                 case '\n':
 334                         return pos;
 335                 }
 336                 line[pos++] = c;
 337                 line[pos] = '\0';
 338         }
 339         if (c == EOF)
 340                 return -1;
 341         return pos;
 342 }
 343
 344 static void
 345 do_convert_from_ssh2(struct passwd *pw)
 346 {
 347         Key *k;
 348         int blen;
 349         u_int len;
 350         char line[1024];
 351         u_char blob[8096];
 352         char encoded[8096];
 353         struct stat st;
 354         int escaped = 0, private = 0, ok;
 355         FILE *fp;
 356
 357         if (!have_identity)
 358                 ask_filename(pw, "Enter file in which the key is");
 359         if (stat(identity_file, &st) < 0) {
 360                 perror(identity_file);
 361                 exit(1);
 362         }
 363         fp = fopen(identity_file, "r");
 364         if (fp == NULL) {
 365                 perror(identity_file);
 366                 exit(1);
 367         }
 368         encoded[0] = '\0';
 369         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 370                 if (line[blen - 1] == '\\')
 371                         escaped++;
 372                 if (strncmp(line, "----", 4) == 0 ||
 373                     strstr(line, ": ") != NULL) {
 374                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 375                                 private = 1;
 376                         if (strstr(line, " END ") != NULL) {
 377                                 break;
 378                         }
 379                         /* fprintf(stderr, "ignore: %s", line); */
 380                         continue;
 381                 }
 382                 if (escaped) {
 383                         escaped--;
 384                         /* fprintf(stderr, "escaped: %s", line); */
 385                         continue;
 386                 }
 387                 strlcat(encoded, line, sizeof(encoded));
 388         }
 389         len = strlen(encoded);
 390         if (((len % 4) == 3) &&
 391             (encoded[len-1] == '=') &&
 392             (encoded[len-2] == '=') &&
 393             (encoded[len-3] == '='))
 394                 encoded[len-3] = '\0';
 395         blen = uudecode(encoded, blob, sizeof(blob));
 396         if (blen < 0) {
 397                 fprintf(stderr, "uudecode failed.\n");
 398                 exit(1);
 399         }
 400         k = private ?
 401             do_convert_private_ssh2_from_blob(blob, blen) :
 402             key_from_blob(blob, blen);
 403         if (k == NULL) {
 404                 fprintf(stderr, "decode blob failed.\n");
 405                 exit(1);
 406         }
 407         ok = private ?
 408             (k->type == KEY_DSA ?
 409                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 410                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 411             key_write(k, stdout);
 412         if (!ok) {
 413                 fprintf(stderr, "key write failed");
 414                 exit(1);
 415         }
 416         key_free(k);
 417         if (!private)
 418                 fprintf(stdout, "\n");
 419         fclose(fp);
 420         exit(0);
 421 }
 422
 423 static void
 424 do_print_public(struct passwd *pw)
 425 {
 426         Key *prv;
 427         struct stat st;
 428
 429         if (!have_identity)
 430                 ask_filename(pw, "Enter file in which the key is");
 431         if (stat(identity_file, &st) < 0) {
 432                 perror(identity_file);
 433                 exit(1);
 434         }
 435         prv = load_identity(identity_file);
 436         if (prv == NULL) {
 437                 fprintf(stderr, "load failed\n");
 438                 exit(1);
 439         }
 440         if (!key_write(prv, stdout))
 441                 fprintf(stderr, "key_write failed");
 442         key_free(prv);
 443         fprintf(stdout, "\n");
 444         exit(0);
 445 }
 446
 447 #ifdef SMARTCARD
 448 static void
 449 do_upload(struct passwd *pw, const char *sc_reader_id)
 450 {
 451         Key *prv = NULL;
 452         struct stat st;
 453         int ret;
 454
 455         if (!have_identity)
 456                 ask_filename(pw, "Enter file in which the key is");
 457         if (stat(identity_file, &st) < 0) {
 458                 perror(identity_file);
 459                 exit(1);
 460         }
 461         prv = load_identity(identity_file);
 462         if (prv == NULL) {
 463                 error("load failed");
 464                 exit(1);
 465         }
 466         ret = sc_put_key(prv, sc_reader_id);
 467         key_free(prv);
 468         if (ret < 0)
 469                 exit(1);
 470         logit("loading key done");
 471         exit(0);
 472 }
 473
 474 static void
 475 do_download(struct passwd *pw, const char *sc_reader_id)
 476 {
 477         Key **keys = NULL;
 478         int i;
 479
 480         keys = sc_get_keys(sc_reader_id, NULL);
 481         if (keys == NULL)
 482                 fatal("cannot read public key from smartcard");
 483         for (i = 0; keys[i]; i++) {
 484                 key_write(keys[i], stdout);
 485                 key_free(keys[i]);
 486                 fprintf(stdout, "\n");
 487         }
 488         xfree(keys);
 489         exit(0);
 490 }
 491 #endif /* SMARTCARD */
 492
 493 static void
 494 do_fingerprint(struct passwd *pw)
 495 {
 496         FILE *f;
 497         Key *public;
 498         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 499         int i, skip = 0, num = 1, invalid = 1;
 500         enum fp_rep rep;
 501         enum fp_type fptype;
 502         struct stat st;
 503
 504         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 505         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 506
 507         if (!have_identity)
 508                 ask_filename(pw, "Enter file in which the key is");
 509         if (stat(identity_file, &st) < 0) {
 510                 perror(identity_file);
 511                 exit(1);
 512         }
 513         public = key_load_public(identity_file, &comment);
 514         if (public != NULL) {
 515                 fp = key_fingerprint(public, fptype, rep);
 516                 printf("%u %s %s\n", key_size(public), fp, comment);
 517                 key_free(public);
 518                 xfree(comment);
 519                 xfree(fp);
 520                 exit(0);
 521         }
 522         if (comment) {
 523                 xfree(comment);
 524                 comment = NULL;
 525         }
 526
 527         f = fopen(identity_file, "r");
 528         if (f != NULL) {
 529                 while (fgets(line, sizeof(line), f)) {
 530                         i = strlen(line) - 1;
 531                         if (line[i] != '\n') {
 532                                 error("line %d too long: %.40s...", num, line);
 533                                 skip = 1;
 534                                 continue;
 535                         }
 536                         num++;
 537                         if (skip) {
 538                                 skip = 0;
 539                                 continue;
 540                         }
 541                         line[i] = '\0';
 542
 543                         /* Skip leading whitespace, empty and comment lines. */
 544                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 545                                 ;
 546                         if (!*cp || *cp == '\n' || *cp == '#')
 547                                 continue ;
 548                         i = strtol(cp, &ep, 10);
 549                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 550                                 int quoted = 0;
 551                                 comment = cp;
 552                                 for (; *cp && (quoted || (*cp != ' ' &&
 553                                     *cp != '\t')); cp++) {
 554                                         if (*cp == '\\' && cp[1] == '"')
 555                                                 cp++;   /* Skip both */
 556                                         else if (*cp == '"')
 557                                                 quoted = !quoted;
 558                                 }
 559                                 if (!*cp)
 560                                         continue;
 561                                 *cp++ = '\0';
 562                         }
 563                         ep = cp;
 564                         public = key_new(KEY_RSA1);
 565                         if (key_read(public, &cp) != 1) {
 566                                 cp = ep;
 567                                 key_free(public);
 568                                 public = key_new(KEY_UNSPEC);
 569                                 if (key_read(public, &cp) != 1) {
 570                                         key_free(public);
 571                                         continue;
 572                                 }
 573                         }
 574                         comment = *cp ? cp : comment;
 575                         fp = key_fingerprint(public, fptype, rep);
 576                         printf("%u %s %s\n", key_size(public), fp,
 577                             comment ? comment : "no comment");
 578                         xfree(fp);
 579                         key_free(public);
 580                         invalid = 0;
 581                 }
 582                 fclose(f);
 583         }
 584         if (invalid) {
 585                 printf("%s is not a public key file.\n", identity_file);
 586                 exit(1);
 587         }
 588         exit(0);
 589 }
 590
 591 static void
 592 print_host(FILE *f, char *name, Key *public, int hash)
 593 {
 594         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 595                 fatal("hash_host failed");
 596         fprintf(f, "%s ", name);
 597         if (!key_write(public, f))
 598                 fatal("key_write failed");
 599         fprintf(f, "\n");
 600 }
 601
 602 static void
 603 do_known_hosts(struct passwd *pw, const char *name)
 604 {
 605         FILE *in, *out = stdout;
 606         Key *public;
 607         char *cp, *cp2, *kp, *kp2;
 608         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 609         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 610
 611         if (!have_identity) {
 612                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 613                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 614                     sizeof(identity_file))
 615                         fatal("Specified known hosts path too long");
 616                 xfree(cp);
 617                 have_identity = 1;
 618         }
 619         if ((in = fopen(identity_file, "r")) == NULL)
 620                 fatal("fopen: %s", strerror(errno));
 621
 622         /*
 623          * Find hosts goes to stdout, hash and deletions happen in-place
 624          * A corner case is ssh-keygen -HF foo, which should go to stdout
 625          */
 626         if (!find_host && (hash_hosts || delete_host)) {
 627                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 628                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 629                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 630                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 631                         fatal("known_hosts path too long");
 632                 umask(077);
 633                 if ((c = mkstemp(tmp)) == -1)
 634                         fatal("mkstemp: %s", strerror(errno));
 635                 if ((out = fdopen(c, "w")) == NULL) {
 636                         c = errno;
 637                         unlink(tmp);
 638                         fatal("fdopen: %s", strerror(c));
 639                 }
 640                 inplace = 1;
 641         }
 642
 643         while (fgets(line, sizeof(line), in)) {
 644                 num++;
 645                 i = strlen(line) - 1;
 646                 if (line[i] != '\n') {
 647                         error("line %d too long: %.40s...", num, line);
 648                         skip = 1;
 649                         invalid = 1;
 650                         continue;
 651                 }
 652                 if (skip) {
 653                         skip = 0;
 654                         continue;
 655                 }
 656                 line[i] = '\0';
 657
 658                 /* Skip leading whitespace, empty and comment lines. */
 659                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 660                         ;
 661                 if (!*cp || *cp == '\n' || *cp == '#') {
 662                         if (inplace)
 663                                 fprintf(out, "%s\n", cp);
 664                         continue;
 665                 }
 666                 /* Find the end of the host name portion. */
 667                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 668                         ;
 669                 if (*kp == '\0' || *(kp + 1) == '\0') {
 670                         error("line %d missing key: %.40s...",
 671                             num, line);
 672                         invalid = 1;
 673                         continue;
 674                 }
 675                 *kp++ = '\0';
 676                 kp2 = kp;
 677
 678                 public = key_new(KEY_RSA1);
 679                 if (key_read(public, &kp) != 1) {
 680                         kp = kp2;
 681                         key_free(public);
 682                         public = key_new(KEY_UNSPEC);
 683                         if (key_read(public, &kp) != 1) {
 684                                 error("line %d invalid key: %.40s...",
 685                                     num, line);
 686                                 key_free(public);
 687                                 invalid = 1;
 688                                 continue;
 689                         }
 690                 }
 691
 692                 if (*cp == HASH_DELIM) {
 693                         if (find_host || delete_host) {
 694                                 cp2 = host_hash(name, cp, strlen(cp));
 695                                 if (cp2 == NULL) {
 696                                         error("line %d: invalid hashed "
 697                                             "name: %.64s...", num, line);
 698                                         invalid = 1;
 699                                         continue;
 700                                 }
 701                                 c = (strcmp(cp2, cp) == 0);
 702                                 if (find_host && c) {
 703                                         printf("# Host %s found: "
 704                                             "line %d type %s\n", name,
 705                                             num, key_type(public));
 706                                         print_host(out, cp, public, 0);
 707                                 }
 708                                 if (delete_host && !c)
 709                                         print_host(out, cp, public, 0);
 710                         } else if (hash_hosts)
 711                                 print_host(out, cp, public, 0);
 712                 } else {
 713                         if (find_host || delete_host) {
 714                                 c = (match_hostname(name, cp,
 715                                     strlen(cp)) == 1);
 716                                 if (find_host && c) {
 717                                         printf("# Host %s found: "
 718                                             "line %d type %s\n", name,
 719                                             num, key_type(public));
 720                                         print_host(out, cp, public, hash_hosts);
 721                                 }
 722                                 if (delete_host && !c)
 723                                         print_host(out, cp, public, 0);
 724                         } else if (hash_hosts) {
 725                                 for (cp2 = strsep(&cp, ",");
 726                                     cp2 != NULL && *cp2 != '\0';
 727                                     cp2 = strsep(&cp, ",")) {
 728                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 729                                                 fprintf(stderr, "Warning: "
 730                                                     "ignoring host name with "
 731                                                     "metacharacters: %.64s\n",
 732                                                     cp2);
 733                                         else
 734                                                 print_host(out, cp2, public, 1);
 735                                 }
 736                                 has_unhashed = 1;
 737                         }
 738                 }
 739                 key_free(public);
 740         }
 741         fclose(in);
 742
 743         if (invalid) {
 744                 fprintf(stderr, "%s is not a valid known_host file.\n",
 745                     identity_file);
 746                 if (inplace) {
 747                         fprintf(stderr, "Not replacing existing known_hosts "
 748                             "file because of errors\n");
 749                         fclose(out);
 750                         unlink(tmp);
 751                 }
 752                 exit(1);
 753         }
 754
 755         if (inplace) {
 756                 fclose(out);
 757
 758                 /* Backup existing file */
 759                 if (unlink(old) == -1 && errno != ENOENT)
 760                         fatal("unlink %.100s: %s", old, strerror(errno));
 761                 if (link(identity_file, old) == -1)
 762                         fatal("link %.100s to %.100s: %s", identity_file, old,
 763                             strerror(errno));
 764                 /* Move new one into place */
 765                 if (rename(tmp, identity_file) == -1) {
 766                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 767                             strerror(errno));
 768                         unlink(tmp);
 769                         unlink(old);
 770                         exit(1);
 771                 }
 772
 773                 fprintf(stderr, "%s updated.\n", identity_file);
 774                 fprintf(stderr, "Original contents retained as %s\n", old);
 775                 if (has_unhashed) {
 776                         fprintf(stderr, "WARNING: %s contains unhashed "
 777                             "entries\n", old);
 778                         fprintf(stderr, "Delete this file to ensure privacy "
 779                             "of hostnames\n");
 780                 }
 781         }
 782
 783         exit(0);
 784 }
 785
 786 /*
 787  * Perform changing a passphrase.  The argument is the passwd structure
 788  * for the current user.
 789  */
 790 static void
 791 do_change_passphrase(struct passwd *pw)
 792 {
 793         char *comment;
 794         char *old_passphrase, *passphrase1, *passphrase2;
 795         struct stat st;
 796         Key *private;
 797
 798         if (!have_identity)
 799                 ask_filename(pw, "Enter file in which the key is");
 800         if (stat(identity_file, &st) < 0) {
 801                 perror(identity_file);
 802                 exit(1);
 803         }
 804         /* Try to load the file with empty passphrase. */
 805         private = key_load_private(identity_file, "", &comment);
 806         if (private == NULL) {
 807                 if (identity_passphrase)
 808                         old_passphrase = xstrdup(identity_passphrase);
 809                 else
 810                         old_passphrase =
 811                             read_passphrase("Enter old passphrase: ",
 812                             RP_ALLOW_STDIN);
 813                 private = key_load_private(identity_file, old_passphrase,
 814                     &comment);
 815                 memset(old_passphrase, 0, strlen(old_passphrase));
 816                 xfree(old_passphrase);
 817                 if (private == NULL) {
 818                         printf("Bad passphrase.\n");
 819                         exit(1);
 820                 }
 821         }
 822         printf("Key has comment '%s'\n", comment);
 823
 824         /* Ask the new passphrase (twice). */
 825         if (identity_new_passphrase) {
 826                 passphrase1 = xstrdup(identity_new_passphrase);
 827                 passphrase2 = NULL;
 828         } else {
 829                 passphrase1 =
 830                         read_passphrase("Enter new passphrase (empty for no "
 831                             "passphrase): ", RP_ALLOW_STDIN);
 832                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 833                     RP_ALLOW_STDIN);
 834
 835                 /* Verify that they are the same. */
 836                 if (strcmp(passphrase1, passphrase2) != 0) {
 837                         memset(passphrase1, 0, strlen(passphrase1));
 838                         memset(passphrase2, 0, strlen(passphrase2));
 839                         xfree(passphrase1);
 840                         xfree(passphrase2);
 841                         printf("Pass phrases do not match.  Try again.\n");
 842                         exit(1);
 843                 }
 844                 /* Destroy the other copy. */
 845                 memset(passphrase2, 0, strlen(passphrase2));
 846                 xfree(passphrase2);
 847         }
 848
 849         /* Save the file using the new passphrase. */
 850         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 851                 printf("Saving the key failed: %s.\n", identity_file);
 852                 memset(passphrase1, 0, strlen(passphrase1));
 853                 xfree(passphrase1);
 854                 key_free(private);
 855                 xfree(comment);
 856                 exit(1);
 857         }
 858         /* Destroy the passphrase and the copy of the key in memory. */
 859         memset(passphrase1, 0, strlen(passphrase1));
 860         xfree(passphrase1);
 861         key_free(private);               /* Destroys contents */
 862         xfree(comment);
 863
 864         printf("Your identification has been saved with the new passphrase.\n");
 865         exit(0);
 866 }
 867
 868 /*
 869  * Print the SSHFP RR.
 870  */
 871 static int
 872 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 873 {
 874         Key *public;
 875         char *comment = NULL;
 876         struct stat st;
 877
 878         if (fname == NULL)
 879                 ask_filename(pw, "Enter file in which the key is");
 880         if (stat(fname, &st) < 0) {
 881                 if (errno == ENOENT)
 882                         return 0;
 883                 perror(fname);
 884                 exit(1);
 885         }
 886         public = key_load_public(fname, &comment);
 887         if (public != NULL) {
 888                 export_dns_rr(hname, public, stdout, print_generic);
 889                 key_free(public);
 890                 xfree(comment);
 891                 return 1;
 892         }
 893         if (comment)
 894                 xfree(comment);
 895
 896         printf("failed to read v2 public key from %s.\n", fname);
 897         exit(1);
 898 }
 899
 900 /*
 901  * Change the comment of a private key file.
 902  */
 903 static void
 904 do_change_comment(struct passwd *pw)
 905 {
 906         char new_comment[1024], *comment, *passphrase;
 907         Key *private;
 908         Key *public;
 909         struct stat st;
 910         FILE *f;
 911         int fd;
 912
 913         if (!have_identity)
 914                 ask_filename(pw, "Enter file in which the key is");
 915         if (stat(identity_file, &st) < 0) {
 916                 perror(identity_file);
 917                 exit(1);
 918         }
 919         private = key_load_private(identity_file, "", &comment);
 920         if (private == NULL) {
 921                 if (identity_passphrase)
 922                         passphrase = xstrdup(identity_passphrase);
 923                 else if (identity_new_passphrase)
 924                         passphrase = xstrdup(identity_new_passphrase);
 925                 else
 926                         passphrase = read_passphrase("Enter passphrase: ",
 927                             RP_ALLOW_STDIN);
 928                 /* Try to load using the passphrase. */
 929                 private = key_load_private(identity_file, passphrase, &comment);
 930                 if (private == NULL) {
 931                         memset(passphrase, 0, strlen(passphrase));
 932                         xfree(passphrase);
 933                         printf("Bad passphrase.\n");
 934                         exit(1);
 935                 }
 936         } else {
 937                 passphrase = xstrdup("");
 938         }
 939         if (private->type != KEY_RSA1) {
 940                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 941                 key_free(private);
 942                 exit(1);
 943         }
 944         printf("Key now has comment '%s'\n", comment);
 945
 946         if (identity_comment) {
 947                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 948         } else {
 949                 printf("Enter new comment: ");
 950                 fflush(stdout);
 951                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 952                         memset(passphrase, 0, strlen(passphrase));
 953                         key_free(private);
 954                         exit(1);
 955                 }
 956                 if (strchr(new_comment, '\n'))
 957                         *strchr(new_comment, '\n') = 0;
 958         }
 959
 960         /* Save the file using the new passphrase. */
 961         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 962                 printf("Saving the key failed: %s.\n", identity_file);
 963                 memset(passphrase, 0, strlen(passphrase));
 964                 xfree(passphrase);
 965                 key_free(private);
 966                 xfree(comment);
 967                 exit(1);
 968         }
 969         memset(passphrase, 0, strlen(passphrase));
 970         xfree(passphrase);
 971         public = key_from_private(private);
 972         key_free(private);
 973
 974         strlcat(identity_file, ".pub", sizeof(identity_file));
 975         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 976         if (fd == -1) {
 977                 printf("Could not save your public key in %s\n", identity_file);
 978                 exit(1);
 979         }
 980         f = fdopen(fd, "w");
 981         if (f == NULL) {
 982                 printf("fdopen %s failed", identity_file);
 983                 exit(1);
 984         }
 985         if (!key_write(public, f))
 986                 fprintf(stderr, "write key failed");
 987         key_free(public);
 988         fprintf(f, " %s\n", new_comment);
 989         fclose(f);
 990
 991         xfree(comment);
 992
 993         printf("The comment in your key file has been changed.\n");
 994         exit(0);
 995 }
 996
 997 static void
 998 usage(void)
 999 {
1000         fprintf(stderr, "Usage: %s [options]\n", __progname);
1001         fprintf(stderr, "Options:\n");
1002         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1003         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1004         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1005         fprintf(stderr, "  -C comment  Provide new comment.\n");
1006         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1007 #ifdef SMARTCARD
1008         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1009 #endif /* SMARTCARD */
1010         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1011         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1012         fprintf(stderr, "  -f filename Filename of the key file.\n");
1013         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1014         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1015         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1016         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1017         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1018         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1019         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1020         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1021         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1022         fprintf(stderr, "  -q          Quiet.\n");
1023         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1024         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1025         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1026         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1027         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1028 #ifdef SMARTCARD
1029         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1030 #endif /* SMARTCARD */
1031         fprintf(stderr, "  -v          Verbose.\n");
1032         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1033         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1034
1035         exit(1);
1036 }
1037
1038 /*
1039  * Main program for key management.
1040  */
1041 int
1042 main(int ac, char **av)
1043 {
1044         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1045         char out_file[MAXPATHLEN], *reader_id = NULL;
1046         char *rr_hostname = NULL;
1047         Key *private, *public;
1048         struct passwd *pw;
1049         struct stat st;
1050         int opt, type, fd, download = 0;
1051         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1052         int do_gen_candidates = 0, do_screen_candidates = 0;
1053         int log_level = SYSLOG_LEVEL_INFO;
1054         BIGNUM *start = NULL;
1055         FILE *f;
1056         const char *errstr;
1057
1058         extern int optind;
1059         extern char *optarg;
1060
1061         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1062         sanitise_stdfd();
1063
1064         __progname = ssh_get_progname(av[0]);
1065
1066         SSLeay_add_all_algorithms();
1067         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1068
1069         init_rng();
1070         seed_rng();
1071
1072         /* we need this for the home * directory.  */
1073         pw = getpwuid(getuid());
1074         if (!pw) {
1075                 printf("You don't exist, go away!\n");
1076                 exit(1);
1077         }
1078         if (gethostname(hostname, sizeof(hostname)) < 0) {
1079                 perror("gethostname");
1080                 exit(1);
1081         }
1082
1083         while ((opt = getopt(ac, av,
1084             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1085                 switch (opt) {
1086                 case 'b':
1087                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1088                         if (errstr)
1089                                 fatal("Bits has bad value %s (%s)",
1090                                         optarg, errstr);
1091                         break;
1092                 case 'F':
1093                         find_host = 1;
1094                         rr_hostname = optarg;
1095                         break;
1096                 case 'H':
1097                         hash_hosts = 1;
1098                         break;
1099                 case 'R':
1100                         delete_host = 1;
1101                         rr_hostname = optarg;
1102                         break;
1103                 case 'l':
1104                         print_fingerprint = 1;
1105                         break;
1106                 case 'B':
1107                         print_bubblebabble = 1;
1108                         break;
1109                 case 'p':
1110                         change_passphrase = 1;
1111                         break;
1112                 case 'c':
1113                         change_comment = 1;
1114                         break;
1115                 case 'f':
1116                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1117                             sizeof(identity_file))
1118                                 fatal("Identity filename too long");
1119                         have_identity = 1;
1120                         break;
1121                 case 'g':
1122                         print_generic = 1;
1123                         break;
1124                 case 'P':
1125                         identity_passphrase = optarg;
1126                         break;
1127                 case 'N':
1128                         identity_new_passphrase = optarg;
1129                         break;
1130                 case 'C':
1131                         identity_comment = optarg;
1132                         break;
1133                 case 'q':
1134                         quiet = 1;
1135                         break;
1136                 case 'e':
1137                 case 'x':
1138                         /* export key */
1139                         convert_to_ssh2 = 1;
1140                         break;
1141                 case 'i':
1142                 case 'X':
1143                         /* import key */
1144                         convert_from_ssh2 = 1;
1145                         break;
1146                 case 'y':
1147                         print_public = 1;
1148                         break;
1149                 case 'd':
1150                         key_type_name = "dsa";
1151                         break;
1152                 case 't':
1153                         key_type_name = optarg;
1154                         break;
1155                 case 'D':
1156                         download = 1;
1157                         /*FALLTHROUGH*/
1158                 case 'U':
1159                         reader_id = optarg;
1160                         break;
1161                 case 'v':
1162                         if (log_level == SYSLOG_LEVEL_INFO)
1163                                 log_level = SYSLOG_LEVEL_DEBUG1;
1164                         else {
1165                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1166                                     log_level < SYSLOG_LEVEL_DEBUG3)
1167                                         log_level++;
1168                         }
1169                         break;
1170                 case 'r':
1171                         rr_hostname = optarg;
1172                         break;
1173                 case 'W':
1174                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1175                             UINT_MAX, &errstr);
1176                         if (errstr)
1177                                 fatal("Desired generator has bad value: %s (%s)",
1178                                         optarg, errstr);
1179                         break;
1180                 case 'a':
1181                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1182                         if (errstr)
1183                                 fatal("Invalid number of trials: %s (%s)",
1184                                         optarg, errstr);
1185                         break;
1186                 case 'M':
1187                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1188                         if (errstr) {
1189                                 fatal("Memory limit is %s: %s", errstr, optarg);
1190                         }
1191                         break;
1192                 case 'G':
1193                         do_gen_candidates = 1;
1194                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1195                             sizeof(out_file))
1196                                 fatal("Output filename too long");
1197                         break;
1198                 case 'T':
1199                         do_screen_candidates = 1;
1200                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1201                             sizeof(out_file))
1202                                 fatal("Output filename too long");
1203                         break;
1204                 case 'S':
1205                         /* XXX - also compare length against bits */
1206                         if (BN_hex2bn(&start, optarg) == 0)
1207                                 fatal("Invalid start point.");
1208                         break;
1209                 case '?':
1210                 default:
1211                         usage();
1212                 }
1213         }
1214
1215         /* reinit */
1216         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1217
1218         if (optind < ac) {
1219                 printf("Too many arguments.\n");
1220                 usage();
1221         }
1222         if (change_passphrase && change_comment) {
1223                 printf("Can only have one of -p and -c.\n");
1224                 usage();
1225         }
1226         if (delete_host || hash_hosts || find_host)
1227                 do_known_hosts(pw, rr_hostname);
1228         if (print_fingerprint || print_bubblebabble)
1229                 do_fingerprint(pw);
1230         if (change_passphrase)
1231                 do_change_passphrase(pw);
1232         if (change_comment)
1233                 do_change_comment(pw);
1234         if (convert_to_ssh2)
1235                 do_convert_to_ssh2(pw);
1236         if (convert_from_ssh2)
1237                 do_convert_from_ssh2(pw);
1238         if (print_public)
1239                 do_print_public(pw);
1240         if (rr_hostname != NULL) {
1241                 unsigned int n = 0;
1242
1243                 if (have_identity) {
1244                         n = do_print_resource_record(pw,
1245                             identity_file, rr_hostname);
1246                         if (n == 0) {
1247                                 perror(identity_file);
1248                                 exit(1);
1249                         }
1250                         exit(0);
1251                 } else {
1252
1253                         n += do_print_resource_record(pw,
1254                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1255                         n += do_print_resource_record(pw,
1256                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1257
1258                         if (n == 0)
1259                                 fatal("no keys found.");
1260                         exit(0);
1261                 }
1262         }
1263         if (reader_id != NULL) {
1264 #ifdef SMARTCARD
1265                 if (download)
1266                         do_download(pw, reader_id);
1267                 else
1268                         do_upload(pw, reader_id);
1269 #else /* SMARTCARD */
1270                 fatal("no support for smartcards.");
1271 #endif /* SMARTCARD */
1272         }
1273
1274         if (do_gen_candidates) {
1275                 FILE *out = fopen(out_file, "w");
1276
1277                 if (out == NULL) {
1278                         error("Couldn't open modulus candidate file \"%s\": %s",
1279                             out_file, strerror(errno));
1280                         return (1);
1281                 }
1282                 if (bits == 0)
1283                         bits = DEFAULT_BITS;
1284                 if (gen_candidates(out, memory, bits, start) != 0)
1285                         fatal("modulus candidate generation failed");
1286
1287                 return (0);
1288         }
1289
1290         if (do_screen_candidates) {
1291                 FILE *in;
1292                 FILE *out = fopen(out_file, "w");
1293
1294                 if (have_identity && strcmp(identity_file, "-") != 0) {
1295                         if ((in = fopen(identity_file, "r")) == NULL) {
1296                                 fatal("Couldn't open modulus candidate "
1297                                     "file \"%s\": %s", identity_file,
1298                                     strerror(errno));
1299                         }
1300                 } else
1301                         in = stdin;
1302
1303                 if (out == NULL) {
1304                         fatal("Couldn't open moduli file \"%s\": %s",
1305                             out_file, strerror(errno));
1306                 }
1307                 if (prime_test(in, out, trials, generator_wanted) != 0)
1308                         fatal("modulus screening failed");
1309                 return (0);
1310         }
1311
1312         arc4random_stir();
1313
1314         if (key_type_name == NULL)
1315                 key_type_name = "rsa";
1316
1317         type = key_type_from_name(key_type_name);
1318         if (type == KEY_UNSPEC) {
1319                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1320                 exit(1);
1321         }
1322         if (bits == 0)
1323                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1324         if (type == KEY_DSA && bits != 1024)
1325                 fatal("DSA keys must be 1024 bits");
1326         if (!quiet)
1327                 printf("Generating public/private %s key pair.\n", key_type_name);
1328         private = key_generate(type, bits);
1329         if (private == NULL) {
1330                 fprintf(stderr, "key_generate failed");
1331                 exit(1);
1332         }
1333         public  = key_from_private(private);
1334
1335         if (!have_identity)
1336                 ask_filename(pw, "Enter file in which to save the key");
1337
1338         /* Create ~/.ssh directory if it doesn't already exist. */
1339         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1340         if (strstr(identity_file, dotsshdir) != NULL &&
1341             stat(dotsshdir, &st) < 0) {
1342                 if (mkdir(dotsshdir, 0700) < 0)
1343                         error("Could not create directory '%s'.", dotsshdir);
1344                 else if (!quiet)
1345                         printf("Created directory '%s'.\n", dotsshdir);
1346         }
1347         /* If the file already exists, ask the user to confirm. */
1348         if (stat(identity_file, &st) >= 0) {
1349                 char yesno[3];
1350                 printf("%s already exists.\n", identity_file);
1351                 printf("Overwrite (y/n)? ");
1352                 fflush(stdout);
1353                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1354                         exit(1);
1355                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1356                         exit(1);
1357         }
1358         /* Ask for a passphrase (twice). */
1359         if (identity_passphrase)
1360                 passphrase1 = xstrdup(identity_passphrase);
1361         else if (identity_new_passphrase)
1362                 passphrase1 = xstrdup(identity_new_passphrase);
1363         else {
1364 passphrase_again:
1365                 passphrase1 =
1366                         read_passphrase("Enter passphrase (empty for no "
1367                             "passphrase): ", RP_ALLOW_STDIN);
1368                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1369                     RP_ALLOW_STDIN);
1370                 if (strcmp(passphrase1, passphrase2) != 0) {
1371                         /*
1372                          * The passphrases do not match.  Clear them and
1373                          * retry.
1374                          */
1375                         memset(passphrase1, 0, strlen(passphrase1));
1376                         memset(passphrase2, 0, strlen(passphrase2));
1377                         xfree(passphrase1);
1378                         xfree(passphrase2);
1379                         printf("Passphrases do not match.  Try again.\n");
1380                         goto passphrase_again;
1381                 }
1382                 /* Clear the other copy of the passphrase. */
1383                 memset(passphrase2, 0, strlen(passphrase2));
1384                 xfree(passphrase2);
1385         }
1386
1387         if (identity_comment) {
1388                 strlcpy(comment, identity_comment, sizeof(comment));
1389         } else {
1390                 /* Create default commend field for the passphrase. */
1391                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1392         }
1393
1394         /* Save the key with the given passphrase and comment. */
1395         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1396                 printf("Saving the key failed: %s.\n", identity_file);
1397                 memset(passphrase1, 0, strlen(passphrase1));
1398                 xfree(passphrase1);
1399                 exit(1);
1400         }
1401         /* Clear the passphrase. */
1402         memset(passphrase1, 0, strlen(passphrase1));
1403         xfree(passphrase1);
1404
1405         /* Clear the private key and the random number generator. */
1406         key_free(private);
1407         arc4random_stir();
1408
1409         if (!quiet)
1410                 printf("Your identification has been saved in %s.\n", identity_file);
1411
1412         strlcat(identity_file, ".pub", sizeof(identity_file));
1413         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1414         if (fd == -1) {
1415                 printf("Could not save your public key in %s\n", identity_file);
1416                 exit(1);
1417         }
1418         f = fdopen(fd, "w");
1419         if (f == NULL) {
1420                 printf("fdopen %s failed", identity_file);
1421                 exit(1);
1422         }
1423         if (!key_write(public, f))
1424                 fprintf(stderr, "write key failed");
1425         fprintf(f, " %s\n", comment);
1426         fclose(f);
1427
1428         if (!quiet) {
1429                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1430                 printf("Your public key has been saved in %s.\n",
1431                     identity_file);
1432                 printf("The key fingerprint is:\n");
1433                 printf("%s %s\n", fp, comment);
1434                 xfree(fp);
1435         }
1436
1437         key_free(public);
1438         exit(0);
1439 }