ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.150 2006/07/22 20:48:23 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 <errno.h>
  25 #include <fcntl.h>
  26 #if defined(HAVE_NETDB_H)
  27 # include <netdb.h>
  28 #endif
  29 #ifdef HAVE_PATHS_H
  30 # include <paths.h>
  31 #endif
  32 #include <pwd.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35
  36 #include "xmalloc.h"
  37 #include "key.h"
  38 #include "rsa.h"
  39 #include "authfile.h"
  40 #include "uuencode.h"
  41 #include "buffer.h"
  42 #include "bufaux.h"
  43 #include "pathnames.h"
  44 #include "log.h"
  45 #include "misc.h"
  46 #include "match.h"
  47 #include "hostfile.h"
  48 #include "dns.h"
  49
  50 #ifdef SMARTCARD
  51 #include "scard.h"
  52 #endif
  53
  54 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  55 #define DEFAULT_BITS            2048
  56 #define DEFAULT_BITS_DSA        1024
  57 u_int32_t bits = 0;
  58
  59 /*
  60  * Flag indicating that we just want to change the passphrase.  This can be
  61  * set on the command line.
  62  */
  63 int change_passphrase = 0;
  64
  65 /*
  66  * Flag indicating that we just want to change the comment.  This can be set
  67  * on the command line.
  68  */
  69 int change_comment = 0;
  70
  71 int quiet = 0;
  72
  73 /* Flag indicating that we want to hash a known_hosts file */
  74 int hash_hosts = 0;
  75 /* Flag indicating that we want lookup a host in known_hosts file */
  76 int find_host = 0;
  77 /* Flag indicating that we want to delete a host from a known_hosts file */
  78 int delete_host = 0;
  79
  80 /* Flag indicating that we just want to see the key fingerprint */
  81 int print_fingerprint = 0;
  82 int print_bubblebabble = 0;
  83
  84 /* The identity file name, given on the command line or entered by the user. */
  85 char identity_file[1024];
  86 int have_identity = 0;
  87
  88 /* This is set to the passphrase if given on the command line. */
  89 char *identity_passphrase = NULL;
  90
  91 /* This is set to the new passphrase if given on the command line. */
  92 char *identity_new_passphrase = NULL;
  93
  94 /* This is set to the new comment if given on the command line. */
  95 char *identity_comment = NULL;
  96
  97 /* Dump public key file in format used by real and the original SSH 2 */
  98 int convert_to_ssh2 = 0;
  99 int convert_from_ssh2 = 0;
 100 int print_public = 0;
 101 int print_generic = 0;
 102
 103 char *key_type_name = NULL;
 104
 105 /* argv0 */
 106 extern char *__progname;
 107
 108 char hostname[MAXHOSTNAMELEN];
 109
 110 /* moduli.c */
 111 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 112 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 113
 114 static void
 115 ask_filename(struct passwd *pw, const char *prompt)
 116 {
 117         char buf[1024];
 118         char *name = NULL;
 119
 120         if (key_type_name == NULL)
 121                 name = _PATH_SSH_CLIENT_ID_RSA;
 122         else {
 123                 switch (key_type_from_name(key_type_name)) {
 124                 case KEY_RSA1:
 125                         name = _PATH_SSH_CLIENT_IDENTITY;
 126                         break;
 127                 case KEY_DSA:
 128                         name = _PATH_SSH_CLIENT_ID_DSA;
 129                         break;
 130                 case KEY_RSA:
 131                         name = _PATH_SSH_CLIENT_ID_RSA;
 132                         break;
 133                 default:
 134                         fprintf(stderr, "bad key type");
 135                         exit(1);
 136                         break;
 137                 }
 138         }
 139         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 140         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 141         if (fgets(buf, sizeof(buf), stdin) == NULL)
 142                 exit(1);
 143         if (strchr(buf, '\n'))
 144                 *strchr(buf, '\n') = 0;
 145         if (strcmp(buf, "") != 0)
 146                 strlcpy(identity_file, buf, sizeof(identity_file));
 147         have_identity = 1;
 148 }
 149
 150 static Key *
 151 load_identity(char *filename)
 152 {
 153         char *pass;
 154         Key *prv;
 155
 156         prv = key_load_private(filename, "", NULL);
 157         if (prv == NULL) {
 158                 if (identity_passphrase)
 159                         pass = xstrdup(identity_passphrase);
 160                 else
 161                         pass = read_passphrase("Enter passphrase: ",
 162                             RP_ALLOW_STDIN);
 163                 prv = key_load_private(filename, pass, NULL);
 164                 memset(pass, 0, strlen(pass));
 165                 xfree(pass);
 166         }
 167         return prv;
 168 }
 169
 170 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 171 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 172 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 173 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 174
 175 static void
 176 do_convert_to_ssh2(struct passwd *pw)
 177 {
 178         Key *k;
 179         u_int len;
 180         u_char *blob;
 181         struct stat st;
 182
 183         if (!have_identity)
 184                 ask_filename(pw, "Enter file in which the key is");
 185         if (stat(identity_file, &st) < 0) {
 186                 perror(identity_file);
 187                 exit(1);
 188         }
 189         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 190                 if ((k = load_identity(identity_file)) == NULL) {
 191                         fprintf(stderr, "load failed\n");
 192                         exit(1);
 193                 }
 194         }
 195         if (k->type == KEY_RSA1) {
 196                 fprintf(stderr, "version 1 keys are not supported\n");
 197                 exit(1);
 198         }
 199         if (key_to_blob(k, &blob, &len) <= 0) {
 200                 fprintf(stderr, "key_to_blob failed\n");
 201                 exit(1);
 202         }
 203         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 204         fprintf(stdout,
 205             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 206             key_size(k), key_type(k),
 207             pw->pw_name, hostname);
 208         dump_base64(stdout, blob, len);
 209         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 210         key_free(k);
 211         xfree(blob);
 212         exit(0);
 213 }
 214
 215 static void
 216 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 217 {
 218         u_int bignum_bits = buffer_get_int(b);
 219         u_int bytes = (bignum_bits + 7) / 8;
 220
 221         if (buffer_len(b) < bytes)
 222                 fatal("buffer_get_bignum_bits: input buffer too small: "
 223                     "need %d have %d", bytes, buffer_len(b));
 224         BN_bin2bn(buffer_ptr(b), bytes, value);
 225         buffer_consume(b, bytes);
 226 }
 227
 228 static Key *
 229 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 230 {
 231         Buffer b;
 232         Key *key = NULL;
 233         char *type, *cipher;
 234         u_char *sig, data[] = "abcde12345";
 235         int magic, rlen, ktype, i1, i2, i3, i4;
 236         u_int slen;
 237         u_long e;
 238
 239         buffer_init(&b);
 240         buffer_append(&b, blob, blen);
 241
 242         magic  = buffer_get_int(&b);
 243         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 244                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 245                 buffer_free(&b);
 246                 return NULL;
 247         }
 248         i1 = buffer_get_int(&b);
 249         type   = buffer_get_string(&b, NULL);
 250         cipher = buffer_get_string(&b, NULL);
 251         i2 = buffer_get_int(&b);
 252         i3 = buffer_get_int(&b);
 253         i4 = buffer_get_int(&b);
 254         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 255         if (strcmp(cipher, "none") != 0) {
 256                 error("unsupported cipher %s", cipher);
 257                 xfree(cipher);
 258                 buffer_free(&b);
 259                 xfree(type);
 260                 return NULL;
 261         }
 262         xfree(cipher);
 263
 264         if (strstr(type, "dsa")) {
 265                 ktype = KEY_DSA;
 266         } else if (strstr(type, "rsa")) {
 267                 ktype = KEY_RSA;
 268         } else {
 269                 buffer_free(&b);
 270                 xfree(type);
 271                 return NULL;
 272         }
 273         key = key_new_private(ktype);
 274         xfree(type);
 275
 276         switch (key->type) {
 277         case KEY_DSA:
 278                 buffer_get_bignum_bits(&b, key->dsa->p);
 279                 buffer_get_bignum_bits(&b, key->dsa->g);
 280                 buffer_get_bignum_bits(&b, key->dsa->q);
 281                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 282                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 283                 break;
 284         case KEY_RSA:
 285                 e  = buffer_get_char(&b);
 286                 debug("e %lx", e);
 287                 if (e < 30) {
 288                         e <<= 8;
 289                         e += buffer_get_char(&b);
 290                         debug("e %lx", e);
 291                         e <<= 8;
 292                         e += buffer_get_char(&b);
 293                         debug("e %lx", e);
 294                 }
 295                 if (!BN_set_word(key->rsa->e, e)) {
 296                         buffer_free(&b);
 297                         key_free(key);
 298                         return NULL;
 299                 }
 300                 buffer_get_bignum_bits(&b, key->rsa->d);
 301                 buffer_get_bignum_bits(&b, key->rsa->n);
 302                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 303                 buffer_get_bignum_bits(&b, key->rsa->q);
 304                 buffer_get_bignum_bits(&b, key->rsa->p);
 305                 rsa_generate_additional_parameters(key->rsa);
 306                 break;
 307         }
 308         rlen = buffer_len(&b);
 309         if (rlen != 0)
 310                 error("do_convert_private_ssh2_from_blob: "
 311                     "remaining bytes in key blob %d", rlen);
 312         buffer_free(&b);
 313
 314         /* try the key */
 315         key_sign(key, &sig, &slen, data, sizeof(data));
 316         key_verify(key, sig, slen, data, sizeof(data));
 317         xfree(sig);
 318         return key;
 319 }
 320
 321 static int
 322 get_line(FILE *fp, char *line, size_t len)
 323 {
 324         int c;
 325         size_t pos = 0;
 326
 327         line[0] = '\0';
 328         while ((c = fgetc(fp)) != EOF) {
 329                 if (pos >= len - 1) {
 330                         fprintf(stderr, "input line too long.\n");
 331                         exit(1);
 332                 }
 333                 switch (c) {
 334                 case '\r':
 335                         c = fgetc(fp);
 336                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 337                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 338                                 exit(1);
 339                         }
 340                         return pos;
 341                 case '\n':
 342                         return pos;
 343                 }
 344                 line[pos++] = c;
 345                 line[pos] = '\0';
 346         }
 347         if (c == EOF)
 348                 return -1;
 349         return pos;
 350 }
 351
 352 static void
 353 do_convert_from_ssh2(struct passwd *pw)
 354 {
 355         Key *k;
 356         int blen;
 357         u_int len;
 358         char line[1024];
 359         u_char blob[8096];
 360         char encoded[8096];
 361         struct stat st;
 362         int escaped = 0, private = 0, ok;
 363         FILE *fp;
 364
 365         if (!have_identity)
 366                 ask_filename(pw, "Enter file in which the key is");
 367         if (stat(identity_file, &st) < 0) {
 368                 perror(identity_file);
 369                 exit(1);
 370         }
 371         fp = fopen(identity_file, "r");
 372         if (fp == NULL) {
 373                 perror(identity_file);
 374                 exit(1);
 375         }
 376         encoded[0] = '\0';
 377         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 378                 if (line[blen - 1] == '\\')
 379                         escaped++;
 380                 if (strncmp(line, "----", 4) == 0 ||
 381                     strstr(line, ": ") != NULL) {
 382                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 383                                 private = 1;
 384                         if (strstr(line, " END ") != NULL) {
 385                                 break;
 386                         }
 387                         /* fprintf(stderr, "ignore: %s", line); */
 388                         continue;
 389                 }
 390                 if (escaped) {
 391                         escaped--;
 392                         /* fprintf(stderr, "escaped: %s", line); */
 393                         continue;
 394                 }
 395                 strlcat(encoded, line, sizeof(encoded));
 396         }
 397         len = strlen(encoded);
 398         if (((len % 4) == 3) &&
 399             (encoded[len-1] == '=') &&
 400             (encoded[len-2] == '=') &&
 401             (encoded[len-3] == '='))
 402                 encoded[len-3] = '\0';
 403         blen = uudecode(encoded, blob, sizeof(blob));
 404         if (blen < 0) {
 405                 fprintf(stderr, "uudecode failed.\n");
 406                 exit(1);
 407         }
 408         k = private ?
 409             do_convert_private_ssh2_from_blob(blob, blen) :
 410             key_from_blob(blob, blen);
 411         if (k == NULL) {
 412                 fprintf(stderr, "decode blob failed.\n");
 413                 exit(1);
 414         }
 415         ok = private ?
 416             (k->type == KEY_DSA ?
 417                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 418                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 419             key_write(k, stdout);
 420         if (!ok) {
 421                 fprintf(stderr, "key write failed");
 422                 exit(1);
 423         }
 424         key_free(k);
 425         if (!private)
 426                 fprintf(stdout, "\n");
 427         fclose(fp);
 428         exit(0);
 429 }
 430
 431 static void
 432 do_print_public(struct passwd *pw)
 433 {
 434         Key *prv;
 435         struct stat st;
 436
 437         if (!have_identity)
 438                 ask_filename(pw, "Enter file in which the key is");
 439         if (stat(identity_file, &st) < 0) {
 440                 perror(identity_file);
 441                 exit(1);
 442         }
 443         prv = load_identity(identity_file);
 444         if (prv == NULL) {
 445                 fprintf(stderr, "load failed\n");
 446                 exit(1);
 447         }
 448         if (!key_write(prv, stdout))
 449                 fprintf(stderr, "key_write failed");
 450         key_free(prv);
 451         fprintf(stdout, "\n");
 452         exit(0);
 453 }
 454
 455 #ifdef SMARTCARD
 456 static void
 457 do_upload(struct passwd *pw, const char *sc_reader_id)
 458 {
 459         Key *prv = NULL;
 460         struct stat st;
 461         int ret;
 462
 463         if (!have_identity)
 464                 ask_filename(pw, "Enter file in which the key is");
 465         if (stat(identity_file, &st) < 0) {
 466                 perror(identity_file);
 467                 exit(1);
 468         }
 469         prv = load_identity(identity_file);
 470         if (prv == NULL) {
 471                 error("load failed");
 472                 exit(1);
 473         }
 474         ret = sc_put_key(prv, sc_reader_id);
 475         key_free(prv);
 476         if (ret < 0)
 477                 exit(1);
 478         logit("loading key done");
 479         exit(0);
 480 }
 481
 482 static void
 483 do_download(struct passwd *pw, const char *sc_reader_id)
 484 {
 485         Key **keys = NULL;
 486         int i;
 487
 488         keys = sc_get_keys(sc_reader_id, NULL);
 489         if (keys == NULL)
 490                 fatal("cannot read public key from smartcard");
 491         for (i = 0; keys[i]; i++) {
 492                 key_write(keys[i], stdout);
 493                 key_free(keys[i]);
 494                 fprintf(stdout, "\n");
 495         }
 496         xfree(keys);
 497         exit(0);
 498 }
 499 #endif /* SMARTCARD */
 500
 501 static void
 502 do_fingerprint(struct passwd *pw)
 503 {
 504         FILE *f;
 505         Key *public;
 506         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 507         int i, skip = 0, num = 1, invalid = 1;
 508         enum fp_rep rep;
 509         enum fp_type fptype;
 510         struct stat st;
 511
 512         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 513         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 514
 515         if (!have_identity)
 516                 ask_filename(pw, "Enter file in which the key is");
 517         if (stat(identity_file, &st) < 0) {
 518                 perror(identity_file);
 519                 exit(1);
 520         }
 521         public = key_load_public(identity_file, &comment);
 522         if (public != NULL) {
 523                 fp = key_fingerprint(public, fptype, rep);
 524                 printf("%u %s %s\n", key_size(public), fp, comment);
 525                 key_free(public);
 526                 xfree(comment);
 527                 xfree(fp);
 528                 exit(0);
 529         }
 530         if (comment) {
 531                 xfree(comment);
 532                 comment = NULL;
 533         }
 534
 535         f = fopen(identity_file, "r");
 536         if (f != NULL) {
 537                 while (fgets(line, sizeof(line), f)) {
 538                         i = strlen(line) - 1;
 539                         if (line[i] != '\n') {
 540                                 error("line %d too long: %.40s...", num, line);
 541                                 skip = 1;
 542                                 continue;
 543                         }
 544                         num++;
 545                         if (skip) {
 546                                 skip = 0;
 547                                 continue;
 548                         }
 549                         line[i] = '\0';
 550
 551                         /* Skip leading whitespace, empty and comment lines. */
 552                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 553                                 ;
 554                         if (!*cp || *cp == '\n' || *cp == '#')
 555                                 continue ;
 556                         i = strtol(cp, &ep, 10);
 557                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 558                                 int quoted = 0;
 559                                 comment = cp;
 560                                 for (; *cp && (quoted || (*cp != ' ' &&
 561                                     *cp != '\t')); cp++) {
 562                                         if (*cp == '\\' && cp[1] == '"')
 563                                                 cp++;   /* Skip both */
 564                                         else if (*cp == '"')
 565                                                 quoted = !quoted;
 566                                 }
 567                                 if (!*cp)
 568                                         continue;
 569                                 *cp++ = '\0';
 570                         }
 571                         ep = cp;
 572                         public = key_new(KEY_RSA1);
 573                         if (key_read(public, &cp) != 1) {
 574                                 cp = ep;
 575                                 key_free(public);
 576                                 public = key_new(KEY_UNSPEC);
 577                                 if (key_read(public, &cp) != 1) {
 578                                         key_free(public);
 579                                         continue;
 580                                 }
 581                         }
 582                         comment = *cp ? cp : comment;
 583                         fp = key_fingerprint(public, fptype, rep);
 584                         printf("%u %s %s\n", key_size(public), fp,
 585                             comment ? comment : "no comment");
 586                         xfree(fp);
 587                         key_free(public);
 588                         invalid = 0;
 589                 }
 590                 fclose(f);
 591         }
 592         if (invalid) {
 593                 printf("%s is not a public key file.\n", identity_file);
 594                 exit(1);
 595         }
 596         exit(0);
 597 }
 598
 599 static void
 600 print_host(FILE *f, char *name, Key *public, int hash)
 601 {
 602         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 603                 fatal("hash_host failed");
 604         fprintf(f, "%s ", name);
 605         if (!key_write(public, f))
 606                 fatal("key_write failed");
 607         fprintf(f, "\n");
 608 }
 609
 610 static void
 611 do_known_hosts(struct passwd *pw, const char *name)
 612 {
 613         FILE *in, *out = stdout;
 614         Key *public;
 615         char *cp, *cp2, *kp, *kp2;
 616         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 617         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 618
 619         if (!have_identity) {
 620                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 621                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 622                     sizeof(identity_file))
 623                         fatal("Specified known hosts path too long");
 624                 xfree(cp);
 625                 have_identity = 1;
 626         }
 627         if ((in = fopen(identity_file, "r")) == NULL)
 628                 fatal("fopen: %s", strerror(errno));
 629
 630         /*
 631          * Find hosts goes to stdout, hash and deletions happen in-place
 632          * A corner case is ssh-keygen -HF foo, which should go to stdout
 633          */
 634         if (!find_host && (hash_hosts || delete_host)) {
 635                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 636                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 637                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 638                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 639                         fatal("known_hosts path too long");
 640                 umask(077);
 641                 if ((c = mkstemp(tmp)) == -1)
 642                         fatal("mkstemp: %s", strerror(errno));
 643                 if ((out = fdopen(c, "w")) == NULL) {
 644                         c = errno;
 645                         unlink(tmp);
 646                         fatal("fdopen: %s", strerror(c));
 647                 }
 648                 inplace = 1;
 649         }
 650
 651         while (fgets(line, sizeof(line), in)) {
 652                 num++;
 653                 i = strlen(line) - 1;
 654                 if (line[i] != '\n') {
 655                         error("line %d too long: %.40s...", num, line);
 656                         skip = 1;
 657                         invalid = 1;
 658                         continue;
 659                 }
 660                 if (skip) {
 661                         skip = 0;
 662                         continue;
 663                 }
 664                 line[i] = '\0';
 665
 666                 /* Skip leading whitespace, empty and comment lines. */
 667                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 668                         ;
 669                 if (!*cp || *cp == '\n' || *cp == '#') {
 670                         if (inplace)
 671                                 fprintf(out, "%s\n", cp);
 672                         continue;
 673                 }
 674                 /* Find the end of the host name portion. */
 675                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 676                         ;
 677                 if (*kp == '\0' || *(kp + 1) == '\0') {
 678                         error("line %d missing key: %.40s...",
 679                             num, line);
 680                         invalid = 1;
 681                         continue;
 682                 }
 683                 *kp++ = '\0';
 684                 kp2 = kp;
 685
 686                 public = key_new(KEY_RSA1);
 687                 if (key_read(public, &kp) != 1) {
 688                         kp = kp2;
 689                         key_free(public);
 690                         public = key_new(KEY_UNSPEC);
 691                         if (key_read(public, &kp) != 1) {
 692                                 error("line %d invalid key: %.40s...",
 693                                     num, line);
 694                                 key_free(public);
 695                                 invalid = 1;
 696                                 continue;
 697                         }
 698                 }
 699
 700                 if (*cp == HASH_DELIM) {
 701                         if (find_host || delete_host) {
 702                                 cp2 = host_hash(name, cp, strlen(cp));
 703                                 if (cp2 == NULL) {
 704                                         error("line %d: invalid hashed "
 705                                             "name: %.64s...", num, line);
 706                                         invalid = 1;
 707                                         continue;
 708                                 }
 709                                 c = (strcmp(cp2, cp) == 0);
 710                                 if (find_host && c) {
 711                                         printf("# Host %s found: "
 712                                             "line %d type %s\n", name,
 713                                             num, key_type(public));
 714                                         print_host(out, cp, public, 0);
 715                                 }
 716                                 if (delete_host && !c)
 717                                         print_host(out, cp, public, 0);
 718                         } else if (hash_hosts)
 719                                 print_host(out, cp, public, 0);
 720                 } else {
 721                         if (find_host || delete_host) {
 722                                 c = (match_hostname(name, cp,
 723                                     strlen(cp)) == 1);
 724                                 if (find_host && c) {
 725                                         printf("# Host %s found: "
 726                                             "line %d type %s\n", name,
 727                                             num, key_type(public));
 728                                         print_host(out, cp, public, hash_hosts);
 729                                 }
 730                                 if (delete_host && !c)
 731                                         print_host(out, cp, public, 0);
 732                         } else if (hash_hosts) {
 733                                 for (cp2 = strsep(&cp, ",");
 734                                     cp2 != NULL && *cp2 != '\0';
 735                                     cp2 = strsep(&cp, ",")) {
 736                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 737                                                 fprintf(stderr, "Warning: "
 738                                                     "ignoring host name with "
 739                                                     "metacharacters: %.64s\n",
 740                                                     cp2);
 741                                         else
 742                                                 print_host(out, cp2, public, 1);
 743                                 }
 744                                 has_unhashed = 1;
 745                         }
 746                 }
 747                 key_free(public);
 748         }
 749         fclose(in);
 750
 751         if (invalid) {
 752                 fprintf(stderr, "%s is not a valid known_host file.\n",
 753                     identity_file);
 754                 if (inplace) {
 755                         fprintf(stderr, "Not replacing existing known_hosts "
 756                             "file because of errors\n");
 757                         fclose(out);
 758                         unlink(tmp);
 759                 }
 760                 exit(1);
 761         }
 762
 763         if (inplace) {
 764                 fclose(out);
 765
 766                 /* Backup existing file */
 767                 if (unlink(old) == -1 && errno != ENOENT)
 768                         fatal("unlink %.100s: %s", old, strerror(errno));
 769                 if (link(identity_file, old) == -1)
 770                         fatal("link %.100s to %.100s: %s", identity_file, old,
 771                             strerror(errno));
 772                 /* Move new one into place */
 773                 if (rename(tmp, identity_file) == -1) {
 774                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 775                             strerror(errno));
 776                         unlink(tmp);
 777                         unlink(old);
 778                         exit(1);
 779                 }
 780
 781                 fprintf(stderr, "%s updated.\n", identity_file);
 782                 fprintf(stderr, "Original contents retained as %s\n", old);
 783                 if (has_unhashed) {
 784                         fprintf(stderr, "WARNING: %s contains unhashed "
 785                             "entries\n", old);
 786                         fprintf(stderr, "Delete this file to ensure privacy "
 787                             "of hostnames\n");
 788                 }
 789         }
 790
 791         exit(0);
 792 }
 793
 794 /*
 795  * Perform changing a passphrase.  The argument is the passwd structure
 796  * for the current user.
 797  */
 798 static void
 799 do_change_passphrase(struct passwd *pw)
 800 {
 801         char *comment;
 802         char *old_passphrase, *passphrase1, *passphrase2;
 803         struct stat st;
 804         Key *private;
 805
 806         if (!have_identity)
 807                 ask_filename(pw, "Enter file in which the key is");
 808         if (stat(identity_file, &st) < 0) {
 809                 perror(identity_file);
 810                 exit(1);
 811         }
 812         /* Try to load the file with empty passphrase. */
 813         private = key_load_private(identity_file, "", &comment);
 814         if (private == NULL) {
 815                 if (identity_passphrase)
 816                         old_passphrase = xstrdup(identity_passphrase);
 817                 else
 818                         old_passphrase =
 819                             read_passphrase("Enter old passphrase: ",
 820                             RP_ALLOW_STDIN);
 821                 private = key_load_private(identity_file, old_passphrase,
 822                     &comment);
 823                 memset(old_passphrase, 0, strlen(old_passphrase));
 824                 xfree(old_passphrase);
 825                 if (private == NULL) {
 826                         printf("Bad passphrase.\n");
 827                         exit(1);
 828                 }
 829         }
 830         printf("Key has comment '%s'\n", comment);
 831
 832         /* Ask the new passphrase (twice). */
 833         if (identity_new_passphrase) {
 834                 passphrase1 = xstrdup(identity_new_passphrase);
 835                 passphrase2 = NULL;
 836         } else {
 837                 passphrase1 =
 838                         read_passphrase("Enter new passphrase (empty for no "
 839                             "passphrase): ", RP_ALLOW_STDIN);
 840                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 841                     RP_ALLOW_STDIN);
 842
 843                 /* Verify that they are the same. */
 844                 if (strcmp(passphrase1, passphrase2) != 0) {
 845                         memset(passphrase1, 0, strlen(passphrase1));
 846                         memset(passphrase2, 0, strlen(passphrase2));
 847                         xfree(passphrase1);
 848                         xfree(passphrase2);
 849                         printf("Pass phrases do not match.  Try again.\n");
 850                         exit(1);
 851                 }
 852                 /* Destroy the other copy. */
 853                 memset(passphrase2, 0, strlen(passphrase2));
 854                 xfree(passphrase2);
 855         }
 856
 857         /* Save the file using the new passphrase. */
 858         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 859                 printf("Saving the key failed: %s.\n", identity_file);
 860                 memset(passphrase1, 0, strlen(passphrase1));
 861                 xfree(passphrase1);
 862                 key_free(private);
 863                 xfree(comment);
 864                 exit(1);
 865         }
 866         /* Destroy the passphrase and the copy of the key in memory. */
 867         memset(passphrase1, 0, strlen(passphrase1));
 868         xfree(passphrase1);
 869         key_free(private);               /* Destroys contents */
 870         xfree(comment);
 871
 872         printf("Your identification has been saved with the new passphrase.\n");
 873         exit(0);
 874 }
 875
 876 /*
 877  * Print the SSHFP RR.
 878  */
 879 static int
 880 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 881 {
 882         Key *public;
 883         char *comment = NULL;
 884         struct stat st;
 885
 886         if (fname == NULL)
 887                 ask_filename(pw, "Enter file in which the key is");
 888         if (stat(fname, &st) < 0) {
 889                 if (errno == ENOENT)
 890                         return 0;
 891                 perror(fname);
 892                 exit(1);
 893         }
 894         public = key_load_public(fname, &comment);
 895         if (public != NULL) {
 896                 export_dns_rr(hname, public, stdout, print_generic);
 897                 key_free(public);
 898                 xfree(comment);
 899                 return 1;
 900         }
 901         if (comment)
 902                 xfree(comment);
 903
 904         printf("failed to read v2 public key from %s.\n", fname);
 905         exit(1);
 906 }
 907
 908 /*
 909  * Change the comment of a private key file.
 910  */
 911 static void
 912 do_change_comment(struct passwd *pw)
 913 {
 914         char new_comment[1024], *comment, *passphrase;
 915         Key *private;
 916         Key *public;
 917         struct stat st;
 918         FILE *f;
 919         int fd;
 920
 921         if (!have_identity)
 922                 ask_filename(pw, "Enter file in which the key is");
 923         if (stat(identity_file, &st) < 0) {
 924                 perror(identity_file);
 925                 exit(1);
 926         }
 927         private = key_load_private(identity_file, "", &comment);
 928         if (private == NULL) {
 929                 if (identity_passphrase)
 930                         passphrase = xstrdup(identity_passphrase);
 931                 else if (identity_new_passphrase)
 932                         passphrase = xstrdup(identity_new_passphrase);
 933                 else
 934                         passphrase = read_passphrase("Enter passphrase: ",
 935                             RP_ALLOW_STDIN);
 936                 /* Try to load using the passphrase. */
 937                 private = key_load_private(identity_file, passphrase, &comment);
 938                 if (private == NULL) {
 939                         memset(passphrase, 0, strlen(passphrase));
 940                         xfree(passphrase);
 941                         printf("Bad passphrase.\n");
 942                         exit(1);
 943                 }
 944         } else {
 945                 passphrase = xstrdup("");
 946         }
 947         if (private->type != KEY_RSA1) {
 948                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 949                 key_free(private);
 950                 exit(1);
 951         }
 952         printf("Key now has comment '%s'\n", comment);
 953
 954         if (identity_comment) {
 955                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 956         } else {
 957                 printf("Enter new comment: ");
 958                 fflush(stdout);
 959                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 960                         memset(passphrase, 0, strlen(passphrase));
 961                         key_free(private);
 962                         exit(1);
 963                 }
 964                 if (strchr(new_comment, '\n'))
 965                         *strchr(new_comment, '\n') = 0;
 966         }
 967
 968         /* Save the file using the new passphrase. */
 969         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 970                 printf("Saving the key failed: %s.\n", identity_file);
 971                 memset(passphrase, 0, strlen(passphrase));
 972                 xfree(passphrase);
 973                 key_free(private);
 974                 xfree(comment);
 975                 exit(1);
 976         }
 977         memset(passphrase, 0, strlen(passphrase));
 978         xfree(passphrase);
 979         public = key_from_private(private);
 980         key_free(private);
 981
 982         strlcat(identity_file, ".pub", sizeof(identity_file));
 983         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 984         if (fd == -1) {
 985                 printf("Could not save your public key in %s\n", identity_file);
 986                 exit(1);
 987         }
 988         f = fdopen(fd, "w");
 989         if (f == NULL) {
 990                 printf("fdopen %s failed", identity_file);
 991                 exit(1);
 992         }
 993         if (!key_write(public, f))
 994                 fprintf(stderr, "write key failed");
 995         key_free(public);
 996         fprintf(f, " %s\n", new_comment);
 997         fclose(f);
 998
 999         xfree(comment);
1000
1001         printf("The comment in your key file has been changed.\n");
1002         exit(0);
1003 }
1004
1005 static void
1006 usage(void)
1007 {
1008         fprintf(stderr, "Usage: %s [options]\n", __progname);
1009         fprintf(stderr, "Options:\n");
1010         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1011         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1012         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1013         fprintf(stderr, "  -C comment  Provide new comment.\n");
1014         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1015 #ifdef SMARTCARD
1016         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1017 #endif /* SMARTCARD */
1018         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1019         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1020         fprintf(stderr, "  -f filename Filename of the key file.\n");
1021         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1022         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1023         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1024         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1025         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1026         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1027         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1028         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1029         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1030         fprintf(stderr, "  -q          Quiet.\n");
1031         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1032         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1033         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1034         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1035         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1036 #ifdef SMARTCARD
1037         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1038 #endif /* SMARTCARD */
1039         fprintf(stderr, "  -v          Verbose.\n");
1040         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1041         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1042
1043         exit(1);
1044 }
1045
1046 /*
1047  * Main program for key management.
1048  */
1049 int
1050 main(int ac, char **av)
1051 {
1052         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1053         char out_file[MAXPATHLEN], *reader_id = NULL;
1054         char *rr_hostname = NULL;
1055         Key *private, *public;
1056         struct passwd *pw;
1057         struct stat st;
1058         int opt, type, fd, download = 0;
1059         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1060         int do_gen_candidates = 0, do_screen_candidates = 0;
1061         int log_level = SYSLOG_LEVEL_INFO;
1062         BIGNUM *start = NULL;
1063         FILE *f;
1064         const char *errstr;
1065
1066         extern int optind;
1067         extern char *optarg;
1068
1069         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1070         sanitise_stdfd();
1071
1072         __progname = ssh_get_progname(av[0]);
1073
1074         SSLeay_add_all_algorithms();
1075         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1076
1077         init_rng();
1078         seed_rng();
1079
1080         /* we need this for the home * directory.  */
1081         pw = getpwuid(getuid());
1082         if (!pw) {
1083                 printf("You don't exist, go away!\n");
1084                 exit(1);
1085         }
1086         if (gethostname(hostname, sizeof(hostname)) < 0) {
1087                 perror("gethostname");
1088                 exit(1);
1089         }
1090
1091         while ((opt = getopt(ac, av,
1092             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1093                 switch (opt) {
1094                 case 'b':
1095                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1096                         if (errstr)
1097                                 fatal("Bits has bad value %s (%s)",
1098                                         optarg, errstr);
1099                         break;
1100                 case 'F':
1101                         find_host = 1;
1102                         rr_hostname = optarg;
1103                         break;
1104                 case 'H':
1105                         hash_hosts = 1;
1106                         break;
1107                 case 'R':
1108                         delete_host = 1;
1109                         rr_hostname = optarg;
1110                         break;
1111                 case 'l':
1112                         print_fingerprint = 1;
1113                         break;
1114                 case 'B':
1115                         print_bubblebabble = 1;
1116                         break;
1117                 case 'p':
1118                         change_passphrase = 1;
1119                         break;
1120                 case 'c':
1121                         change_comment = 1;
1122                         break;
1123                 case 'f':
1124                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1125                             sizeof(identity_file))
1126                                 fatal("Identity filename too long");
1127                         have_identity = 1;
1128                         break;
1129                 case 'g':
1130                         print_generic = 1;
1131                         break;
1132                 case 'P':
1133                         identity_passphrase = optarg;
1134                         break;
1135                 case 'N':
1136                         identity_new_passphrase = optarg;
1137                         break;
1138                 case 'C':
1139                         identity_comment = optarg;
1140                         break;
1141                 case 'q':
1142                         quiet = 1;
1143                         break;
1144                 case 'e':
1145                 case 'x':
1146                         /* export key */
1147                         convert_to_ssh2 = 1;
1148                         break;
1149                 case 'i':
1150                 case 'X':
1151                         /* import key */
1152                         convert_from_ssh2 = 1;
1153                         break;
1154                 case 'y':
1155                         print_public = 1;
1156                         break;
1157                 case 'd':
1158                         key_type_name = "dsa";
1159                         break;
1160                 case 't':
1161                         key_type_name = optarg;
1162                         break;
1163                 case 'D':
1164                         download = 1;
1165                         /*FALLTHROUGH*/
1166                 case 'U':
1167                         reader_id = optarg;
1168                         break;
1169                 case 'v':
1170                         if (log_level == SYSLOG_LEVEL_INFO)
1171                                 log_level = SYSLOG_LEVEL_DEBUG1;
1172                         else {
1173                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1174                                     log_level < SYSLOG_LEVEL_DEBUG3)
1175                                         log_level++;
1176                         }
1177                         break;
1178                 case 'r':
1179                         rr_hostname = optarg;
1180                         break;
1181                 case 'W':
1182                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1183                             UINT_MAX, &errstr);
1184                         if (errstr)
1185                                 fatal("Desired generator has bad value: %s (%s)",
1186                                         optarg, errstr);
1187                         break;
1188                 case 'a':
1189                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1190                         if (errstr)
1191                                 fatal("Invalid number of trials: %s (%s)",
1192                                         optarg, errstr);
1193                         break;
1194                 case 'M':
1195                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1196                         if (errstr) {
1197                                 fatal("Memory limit is %s: %s", errstr, optarg);
1198                         }
1199                         break;
1200                 case 'G':
1201                         do_gen_candidates = 1;
1202                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1203                             sizeof(out_file))
1204                                 fatal("Output filename too long");
1205                         break;
1206                 case 'T':
1207                         do_screen_candidates = 1;
1208                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1209                             sizeof(out_file))
1210                                 fatal("Output filename too long");
1211                         break;
1212                 case 'S':
1213                         /* XXX - also compare length against bits */
1214                         if (BN_hex2bn(&start, optarg) == 0)
1215                                 fatal("Invalid start point.");
1216                         break;
1217                 case '?':
1218                 default:
1219                         usage();
1220                 }
1221         }
1222
1223         /* reinit */
1224         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1225
1226         if (optind < ac) {
1227                 printf("Too many arguments.\n");
1228                 usage();
1229         }
1230         if (change_passphrase && change_comment) {
1231                 printf("Can only have one of -p and -c.\n");
1232                 usage();
1233         }
1234         if (delete_host || hash_hosts || find_host)
1235                 do_known_hosts(pw, rr_hostname);
1236         if (print_fingerprint || print_bubblebabble)
1237                 do_fingerprint(pw);
1238         if (change_passphrase)
1239                 do_change_passphrase(pw);
1240         if (change_comment)
1241                 do_change_comment(pw);
1242         if (convert_to_ssh2)
1243                 do_convert_to_ssh2(pw);
1244         if (convert_from_ssh2)
1245                 do_convert_from_ssh2(pw);
1246         if (print_public)
1247                 do_print_public(pw);
1248         if (rr_hostname != NULL) {
1249                 unsigned int n = 0;
1250
1251                 if (have_identity) {
1252                         n = do_print_resource_record(pw,
1253                             identity_file, rr_hostname);
1254                         if (n == 0) {
1255                                 perror(identity_file);
1256                                 exit(1);
1257                         }
1258                         exit(0);
1259                 } else {
1260
1261                         n += do_print_resource_record(pw,
1262                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1263                         n += do_print_resource_record(pw,
1264                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1265
1266                         if (n == 0)
1267                                 fatal("no keys found.");
1268                         exit(0);
1269                 }
1270         }
1271         if (reader_id != NULL) {
1272 #ifdef SMARTCARD
1273                 if (download)
1274                         do_download(pw, reader_id);
1275                 else
1276                         do_upload(pw, reader_id);
1277 #else /* SMARTCARD */
1278                 fatal("no support for smartcards.");
1279 #endif /* SMARTCARD */
1280         }
1281
1282         if (do_gen_candidates) {
1283                 FILE *out = fopen(out_file, "w");
1284
1285                 if (out == NULL) {
1286                         error("Couldn't open modulus candidate file \"%s\": %s",
1287                             out_file, strerror(errno));
1288                         return (1);
1289                 }
1290                 if (bits == 0)
1291                         bits = DEFAULT_BITS;
1292                 if (gen_candidates(out, memory, bits, start) != 0)
1293                         fatal("modulus candidate generation failed");
1294
1295                 return (0);
1296         }
1297
1298         if (do_screen_candidates) {
1299                 FILE *in;
1300                 FILE *out = fopen(out_file, "w");
1301
1302                 if (have_identity && strcmp(identity_file, "-") != 0) {
1303                         if ((in = fopen(identity_file, "r")) == NULL) {
1304                                 fatal("Couldn't open modulus candidate "
1305                                     "file \"%s\": %s", identity_file,
1306                                     strerror(errno));
1307                         }
1308                 } else
1309                         in = stdin;
1310
1311                 if (out == NULL) {
1312                         fatal("Couldn't open moduli file \"%s\": %s",
1313                             out_file, strerror(errno));
1314                 }
1315                 if (prime_test(in, out, trials, generator_wanted) != 0)
1316                         fatal("modulus screening failed");
1317                 return (0);
1318         }
1319
1320         arc4random_stir();
1321
1322         if (key_type_name == NULL)
1323                 key_type_name = "rsa";
1324
1325         type = key_type_from_name(key_type_name);
1326         if (type == KEY_UNSPEC) {
1327                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1328                 exit(1);
1329         }
1330         if (bits == 0)
1331                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1332         if (type == KEY_DSA && bits != 1024)
1333                 fatal("DSA keys must be 1024 bits");
1334         if (!quiet)
1335                 printf("Generating public/private %s key pair.\n", key_type_name);
1336         private = key_generate(type, bits);
1337         if (private == NULL) {
1338                 fprintf(stderr, "key_generate failed");
1339                 exit(1);
1340         }
1341         public  = key_from_private(private);
1342
1343         if (!have_identity)
1344                 ask_filename(pw, "Enter file in which to save the key");
1345
1346         /* Create ~/.ssh directory if it doesn't already exist. */
1347         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1348         if (strstr(identity_file, dotsshdir) != NULL &&
1349             stat(dotsshdir, &st) < 0) {
1350                 if (mkdir(dotsshdir, 0700) < 0)
1351                         error("Could not create directory '%s'.", dotsshdir);
1352                 else if (!quiet)
1353                         printf("Created directory '%s'.\n", dotsshdir);
1354         }
1355         /* If the file already exists, ask the user to confirm. */
1356         if (stat(identity_file, &st) >= 0) {
1357                 char yesno[3];
1358                 printf("%s already exists.\n", identity_file);
1359                 printf("Overwrite (y/n)? ");
1360                 fflush(stdout);
1361                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1362                         exit(1);
1363                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1364                         exit(1);
1365         }
1366         /* Ask for a passphrase (twice). */
1367         if (identity_passphrase)
1368                 passphrase1 = xstrdup(identity_passphrase);
1369         else if (identity_new_passphrase)
1370                 passphrase1 = xstrdup(identity_new_passphrase);
1371         else {
1372 passphrase_again:
1373                 passphrase1 =
1374                         read_passphrase("Enter passphrase (empty for no "
1375                             "passphrase): ", RP_ALLOW_STDIN);
1376                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1377                     RP_ALLOW_STDIN);
1378                 if (strcmp(passphrase1, passphrase2) != 0) {
1379                         /*
1380                          * The passphrases do not match.  Clear them and
1381                          * retry.
1382                          */
1383                         memset(passphrase1, 0, strlen(passphrase1));
1384                         memset(passphrase2, 0, strlen(passphrase2));
1385                         xfree(passphrase1);
1386                         xfree(passphrase2);
1387                         printf("Passphrases do not match.  Try again.\n");
1388                         goto passphrase_again;
1389                 }
1390                 /* Clear the other copy of the passphrase. */
1391                 memset(passphrase2, 0, strlen(passphrase2));
1392                 xfree(passphrase2);
1393         }
1394
1395         if (identity_comment) {
1396                 strlcpy(comment, identity_comment, sizeof(comment));
1397         } else {
1398                 /* Create default commend field for the passphrase. */
1399                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1400         }
1401
1402         /* Save the key with the given passphrase and comment. */
1403         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1404                 printf("Saving the key failed: %s.\n", identity_file);
1405                 memset(passphrase1, 0, strlen(passphrase1));
1406                 xfree(passphrase1);
1407                 exit(1);
1408         }
1409         /* Clear the passphrase. */
1410         memset(passphrase1, 0, strlen(passphrase1));
1411         xfree(passphrase1);
1412
1413         /* Clear the private key and the random number generator. */
1414         key_free(private);
1415         arc4random_stir();
1416
1417         if (!quiet)
1418                 printf("Your identification has been saved in %s.\n", identity_file);
1419
1420         strlcat(identity_file, ".pub", sizeof(identity_file));
1421         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1422         if (fd == -1) {
1423                 printf("Could not save your public key in %s\n", identity_file);
1424                 exit(1);
1425         }
1426         f = fdopen(fd, "w");
1427         if (f == NULL) {
1428                 printf("fdopen %s failed", identity_file);
1429                 exit(1);
1430         }
1431         if (!key_write(public, f))
1432                 fprintf(stderr, "write key failed");
1433         fprintf(f, " %s\n", comment);
1434         fclose(f);
1435
1436         if (!quiet) {
1437                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1438                 printf("Your public key has been saved in %s.\n",
1439                     identity_file);
1440                 printf("The key fingerprint is:\n");
1441                 printf("%s %s\n", fp, comment);
1442                 xfree(fp);
1443         }
1444
1445         key_free(public);
1446         exit(0);
1447 }