ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.163 2007/10/02 17:49:58 chl 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 #include <sys/param.h>
  21
  22 #include <openssl/evp.h>
  23 #include <openssl/pem.h>
  24
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <netdb.h>
  28 #ifdef HAVE_PATHS_H
  29 # include <paths.h>
  30 #endif
  31 #include <pwd.h>
  32 #include <stdarg.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <unistd.h>
  37
  38 #include "xmalloc.h"
  39 #include "key.h"
  40 #include "rsa.h"
  41 #include "authfile.h"
  42 #include "uuencode.h"
  43 #include "buffer.h"
  44 #include "pathnames.h"
  45 #include "log.h"
  46 #include "misc.h"
  47 #include "match.h"
  48 #include "hostfile.h"
  49 #include "dns.h"
  50
  51 #ifdef SMARTCARD
  52 #include "scard.h"
  53 #endif
  54
  55 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  56 #define DEFAULT_BITS            2048
  57 #define DEFAULT_BITS_DSA        1024
  58 u_int32_t bits = 0;
  59
  60 /*
  61  * Flag indicating that we just want to change the passphrase.  This can be
  62  * set on the command line.
  63  */
  64 int change_passphrase = 0;
  65
  66 /*
  67  * Flag indicating that we just want to change the comment.  This can be set
  68  * on the command line.
  69  */
  70 int change_comment = 0;
  71
  72 int quiet = 0;
  73
  74 /* Flag indicating that we want to hash a known_hosts file */
  75 int hash_hosts = 0;
  76 /* Flag indicating that we want lookup a host in known_hosts file */
  77 int find_host = 0;
  78 /* Flag indicating that we want to delete a host from a known_hosts file */
  79 int delete_host = 0;
  80
  81 /* Flag indicating that we just want to see the key fingerprint */
  82 int print_fingerprint = 0;
  83 int print_bubblebabble = 0;
  84
  85 /* The identity file name, given on the command line or entered by the user. */
  86 char identity_file[1024];
  87 int have_identity = 0;
  88
  89 /* This is set to the passphrase if given on the command line. */
  90 char *identity_passphrase = NULL;
  91
  92 /* This is set to the new passphrase if given on the command line. */
  93 char *identity_new_passphrase = NULL;
  94
  95 /* This is set to the new comment if given on the command line. */
  96 char *identity_comment = NULL;
  97
  98 /* Dump public key file in format used by real and the original SSH 2 */
  99 int convert_to_ssh2 = 0;
 100 int convert_from_ssh2 = 0;
 101 int print_public = 0;
 102 int print_generic = 0;
 103
 104 char *key_type_name = NULL;
 105
 106 /* argv0 */
 107 extern char *__progname;
 108
 109 char hostname[MAXHOSTNAMELEN];
 110
 111 /* moduli.c */
 112 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 113 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 114
 115 static void
 116 ask_filename(struct passwd *pw, const char *prompt)
 117 {
 118         char buf[1024];
 119         char *name = NULL;
 120
 121         if (key_type_name == NULL)
 122                 name = _PATH_SSH_CLIENT_ID_RSA;
 123         else {
 124                 switch (key_type_from_name(key_type_name)) {
 125                 case KEY_RSA1:
 126                         name = _PATH_SSH_CLIENT_IDENTITY;
 127                         break;
 128                 case KEY_DSA:
 129                         name = _PATH_SSH_CLIENT_ID_DSA;
 130                         break;
 131                 case KEY_RSA:
 132                         name = _PATH_SSH_CLIENT_ID_RSA;
 133                         break;
 134                 default:
 135                         fprintf(stderr, "bad key type");
 136                         exit(1);
 137                         break;
 138                 }
 139         }
 140         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 141         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 142         if (fgets(buf, sizeof(buf), stdin) == NULL)
 143                 exit(1);
 144         buf[strcspn(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         if (BN_bin2bn(buffer_ptr(b), bytes, value) == NULL)
 225                 fatal("buffer_get_bignum_bits: BN_bin2bn failed");
 226         buffer_consume(b, bytes);
 227 }
 228
 229 static Key *
 230 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 231 {
 232         Buffer b;
 233         Key *key = NULL;
 234         char *type, *cipher;
 235         u_char *sig, data[] = "abcde12345";
 236         int magic, rlen, ktype, i1, i2, i3, i4;
 237         u_int slen;
 238         u_long e;
 239
 240         buffer_init(&b);
 241         buffer_append(&b, blob, blen);
 242
 243         magic = buffer_get_int(&b);
 244         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 245                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 246                 buffer_free(&b);
 247                 return NULL;
 248         }
 249         i1 = buffer_get_int(&b);
 250         type   = buffer_get_string(&b, NULL);
 251         cipher = buffer_get_string(&b, NULL);
 252         i2 = buffer_get_int(&b);
 253         i3 = buffer_get_int(&b);
 254         i4 = buffer_get_int(&b);
 255         debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
 256         if (strcmp(cipher, "none") != 0) {
 257                 error("unsupported cipher %s", cipher);
 258                 xfree(cipher);
 259                 buffer_free(&b);
 260                 xfree(type);
 261                 return NULL;
 262         }
 263         xfree(cipher);
 264
 265         if (strstr(type, "dsa")) {
 266                 ktype = KEY_DSA;
 267         } else if (strstr(type, "rsa")) {
 268                 ktype = KEY_RSA;
 269         } else {
 270                 buffer_free(&b);
 271                 xfree(type);
 272                 return NULL;
 273         }
 274         key = key_new_private(ktype);
 275         xfree(type);
 276
 277         switch (key->type) {
 278         case KEY_DSA:
 279                 buffer_get_bignum_bits(&b, key->dsa->p);
 280                 buffer_get_bignum_bits(&b, key->dsa->g);
 281                 buffer_get_bignum_bits(&b, key->dsa->q);
 282                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 283                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 284                 break;
 285         case KEY_RSA:
 286                 e = buffer_get_char(&b);
 287                 debug("e %lx", e);
 288                 if (e < 30) {
 289                         e <<= 8;
 290                         e += buffer_get_char(&b);
 291                         debug("e %lx", e);
 292                         e <<= 8;
 293                         e += buffer_get_char(&b);
 294                         debug("e %lx", e);
 295                 }
 296                 if (!BN_set_word(key->rsa->e, e)) {
 297                         buffer_free(&b);
 298                         key_free(key);
 299                         return NULL;
 300                 }
 301                 buffer_get_bignum_bits(&b, key->rsa->d);
 302                 buffer_get_bignum_bits(&b, key->rsa->n);
 303                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 304                 buffer_get_bignum_bits(&b, key->rsa->q);
 305                 buffer_get_bignum_bits(&b, key->rsa->p);
 306                 rsa_generate_additional_parameters(key->rsa);
 307                 break;
 308         }
 309         rlen = buffer_len(&b);
 310         if (rlen != 0)
 311                 error("do_convert_private_ssh2_from_blob: "
 312                     "remaining bytes in key blob %d", rlen);
 313         buffer_free(&b);
 314
 315         /* try the key */
 316         key_sign(key, &sig, &slen, data, sizeof(data));
 317         key_verify(key, sig, slen, data, sizeof(data));
 318         xfree(sig);
 319         return key;
 320 }
 321
 322 static int
 323 get_line(FILE *fp, char *line, size_t len)
 324 {
 325         int c;
 326         size_t pos = 0;
 327
 328         line[0] = '\0';
 329         while ((c = fgetc(fp)) != EOF) {
 330                 if (pos >= len - 1) {
 331                         fprintf(stderr, "input line too long.\n");
 332                         exit(1);
 333                 }
 334                 switch (c) {
 335                 case '\r':
 336                         c = fgetc(fp);
 337                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 338                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 339                                 exit(1);
 340                         }
 341                         return pos;
 342                 case '\n':
 343                         return pos;
 344                 }
 345                 line[pos++] = c;
 346                 line[pos] = '\0';
 347         }
 348         /* We reached EOF */
 349         return -1;
 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                         if ((cp = strchr(line, '\n')) == NULL) {
 539                                 error("line %d too long: %.40s...", num, line);
 540                                 skip = 1;
 541                                 continue;
 542                         }
 543                         num++;
 544                         if (skip) {
 545                                 skip = 0;
 546                                 continue;
 547                         }
 548                         *cp = '\0';
 549
 550                         /* Skip leading whitespace, empty and comment lines. */
 551                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 552                                 ;
 553                         if (!*cp || *cp == '\n' || *cp == '#')
 554                                 continue;
 555                         i = strtol(cp, &ep, 10);
 556                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 557                                 int quoted = 0;
 558                                 comment = cp;
 559                                 for (; *cp && (quoted || (*cp != ' ' &&
 560                                     *cp != '\t')); cp++) {
 561                                         if (*cp == '\\' && cp[1] == '"')
 562                                                 cp++;   /* Skip both */
 563                                         else if (*cp == '"')
 564                                                 quoted = !quoted;
 565                                 }
 566                                 if (!*cp)
 567                                         continue;
 568                                 *cp++ = '\0';
 569                         }
 570                         ep = cp;
 571                         public = key_new(KEY_RSA1);
 572                         if (key_read(public, &cp) != 1) {
 573                                 cp = ep;
 574                                 key_free(public);
 575                                 public = key_new(KEY_UNSPEC);
 576                                 if (key_read(public, &cp) != 1) {
 577                                         key_free(public);
 578                                         continue;
 579                                 }
 580                         }
 581                         comment = *cp ? cp : comment;
 582                         fp = key_fingerprint(public, fptype, rep);
 583                         printf("%u %s %s\n", key_size(public), fp,
 584                             comment ? comment : "no comment");
 585                         xfree(fp);
 586                         key_free(public);
 587                         invalid = 0;
 588                 }
 589                 fclose(f);
 590         }
 591         if (invalid) {
 592                 printf("%s is not a public key file.\n", identity_file);
 593                 exit(1);
 594         }
 595         exit(0);
 596 }
 597
 598 static void
 599 print_host(FILE *f, char *name, Key *public, int hash)
 600 {
 601         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 602                 fatal("hash_host failed");
 603         fprintf(f, "%s ", name);
 604         if (!key_write(public, f))
 605                 fatal("key_write failed");
 606         fprintf(f, "\n");
 607 }
 608
 609 static void
 610 do_known_hosts(struct passwd *pw, const char *name)
 611 {
 612         FILE *in, *out = stdout;
 613         Key *public;
 614         char *cp, *cp2, *kp, *kp2;
 615         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 616         int c, skip = 0, inplace = 0, num = 1, invalid = 0, has_unhashed = 0;
 617
 618         if (!have_identity) {
 619                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 620                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 621                     sizeof(identity_file))
 622                         fatal("Specified known hosts path too long");
 623                 xfree(cp);
 624                 have_identity = 1;
 625         }
 626         if ((in = fopen(identity_file, "r")) == NULL)
 627                 fatal("fopen: %s", strerror(errno));
 628
 629         /*
 630          * Find hosts goes to stdout, hash and deletions happen in-place
 631          * A corner case is ssh-keygen -HF foo, which should go to stdout
 632          */
 633         if (!find_host && (hash_hosts || delete_host)) {
 634                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 635                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 636                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 637                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 638                         fatal("known_hosts path too long");
 639                 umask(077);
 640                 if ((c = mkstemp(tmp)) == -1)
 641                         fatal("mkstemp: %s", strerror(errno));
 642                 if ((out = fdopen(c, "w")) == NULL) {
 643                         c = errno;
 644                         unlink(tmp);
 645                         fatal("fdopen: %s", strerror(c));
 646                 }
 647                 inplace = 1;
 648         }
 649
 650         while (fgets(line, sizeof(line), in)) {
 651                 if ((cp = strchr(line, '\n')) == NULL) {
 652                         error("line %d too long: %.40s...", num, line);
 653                         skip = 1;
 654                         invalid = 1;
 655                         continue;
 656                 }
 657                 num++;
 658                 if (skip) {
 659                         skip = 0;
 660                         continue;
 661                 }
 662                 *cp = '\0';
 663
 664                 /* Skip leading whitespace, empty and comment lines. */
 665                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 666                         ;
 667                 if (!*cp || *cp == '\n' || *cp == '#') {
 668                         if (inplace)
 669                                 fprintf(out, "%s\n", cp);
 670                         continue;
 671                 }
 672                 /* Find the end of the host name portion. */
 673                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 674                         ;
 675                 if (*kp == '\0' || *(kp + 1) == '\0') {
 676                         error("line %d missing key: %.40s...",
 677                             num, line);
 678                         invalid = 1;
 679                         continue;
 680                 }
 681                 *kp++ = '\0';
 682                 kp2 = kp;
 683
 684                 public = key_new(KEY_RSA1);
 685                 if (key_read(public, &kp) != 1) {
 686                         kp = kp2;
 687                         key_free(public);
 688                         public = key_new(KEY_UNSPEC);
 689                         if (key_read(public, &kp) != 1) {
 690                                 error("line %d invalid key: %.40s...",
 691                                     num, line);
 692                                 key_free(public);
 693                                 invalid = 1;
 694                                 continue;
 695                         }
 696                 }
 697
 698                 if (*cp == HASH_DELIM) {
 699                         if (find_host || delete_host) {
 700                                 cp2 = host_hash(name, cp, strlen(cp));
 701                                 if (cp2 == NULL) {
 702                                         error("line %d: invalid hashed "
 703                                             "name: %.64s...", num, line);
 704                                         invalid = 1;
 705                                         continue;
 706                                 }
 707                                 c = (strcmp(cp2, cp) == 0);
 708                                 if (find_host && c) {
 709                                         printf("# Host %s found: "
 710                                             "line %d type %s\n", name,
 711                                             num, key_type(public));
 712                                         print_host(out, cp, public, 0);
 713                                 }
 714                                 if (delete_host && !c)
 715                                         print_host(out, cp, public, 0);
 716                         } else if (hash_hosts)
 717                                 print_host(out, cp, public, 0);
 718                 } else {
 719                         if (find_host || delete_host) {
 720                                 c = (match_hostname(name, cp,
 721                                     strlen(cp)) == 1);
 722                                 if (find_host && c) {
 723                                         printf("# Host %s found: "
 724                                             "line %d type %s\n", name,
 725                                             num, key_type(public));
 726                                         print_host(out, cp, public, hash_hosts);
 727                                 }
 728                                 if (delete_host && !c)
 729                                         print_host(out, cp, public, 0);
 730                         } else if (hash_hosts) {
 731                                 for (cp2 = strsep(&cp, ",");
 732                                     cp2 != NULL && *cp2 != '\0';
 733                                     cp2 = strsep(&cp, ",")) {
 734                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 735                                                 fprintf(stderr, "Warning: "
 736                                                     "ignoring host name with "
 737                                                     "metacharacters: %.64s\n",
 738                                                     cp2);
 739                                         else
 740                                                 print_host(out, cp2, public, 1);
 741                                 }
 742                                 has_unhashed = 1;
 743                         }
 744                 }
 745                 key_free(public);
 746         }
 747         fclose(in);
 748
 749         if (invalid) {
 750                 fprintf(stderr, "%s is not a valid known_host file.\n",
 751                     identity_file);
 752                 if (inplace) {
 753                         fprintf(stderr, "Not replacing existing known_hosts "
 754                             "file because of errors\n");
 755                         fclose(out);
 756                         unlink(tmp);
 757                 }
 758                 exit(1);
 759         }
 760
 761         if (inplace) {
 762                 fclose(out);
 763
 764                 /* Backup existing file */
 765                 if (unlink(old) == -1 && errno != ENOENT)
 766                         fatal("unlink %.100s: %s", old, strerror(errno));
 767                 if (link(identity_file, old) == -1)
 768                         fatal("link %.100s to %.100s: %s", identity_file, old,
 769                             strerror(errno));
 770                 /* Move new one into place */
 771                 if (rename(tmp, identity_file) == -1) {
 772                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 773                             strerror(errno));
 774                         unlink(tmp);
 775                         unlink(old);
 776                         exit(1);
 777                 }
 778
 779                 fprintf(stderr, "%s updated.\n", identity_file);
 780                 fprintf(stderr, "Original contents retained as %s\n", old);
 781                 if (has_unhashed) {
 782                         fprintf(stderr, "WARNING: %s contains unhashed "
 783                             "entries\n", old);
 784                         fprintf(stderr, "Delete this file to ensure privacy "
 785                             "of hostnames\n");
 786                 }
 787         }
 788
 789         exit(0);
 790 }
 791
 792 /*
 793  * Perform changing a passphrase.  The argument is the passwd structure
 794  * for the current user.
 795  */
 796 static void
 797 do_change_passphrase(struct passwd *pw)
 798 {
 799         char *comment;
 800         char *old_passphrase, *passphrase1, *passphrase2;
 801         struct stat st;
 802         Key *private;
 803
 804         if (!have_identity)
 805                 ask_filename(pw, "Enter file in which the key is");
 806         if (stat(identity_file, &st) < 0) {
 807                 perror(identity_file);
 808                 exit(1);
 809         }
 810         /* Try to load the file with empty passphrase. */
 811         private = key_load_private(identity_file, "", &comment);
 812         if (private == NULL) {
 813                 if (identity_passphrase)
 814                         old_passphrase = xstrdup(identity_passphrase);
 815                 else
 816                         old_passphrase =
 817                             read_passphrase("Enter old passphrase: ",
 818                             RP_ALLOW_STDIN);
 819                 private = key_load_private(identity_file, old_passphrase,
 820                     &comment);
 821                 memset(old_passphrase, 0, strlen(old_passphrase));
 822                 xfree(old_passphrase);
 823                 if (private == NULL) {
 824                         printf("Bad passphrase.\n");
 825                         exit(1);
 826                 }
 827         }
 828         printf("Key has comment '%s'\n", comment);
 829
 830         /* Ask the new passphrase (twice). */
 831         if (identity_new_passphrase) {
 832                 passphrase1 = xstrdup(identity_new_passphrase);
 833                 passphrase2 = NULL;
 834         } else {
 835                 passphrase1 =
 836                         read_passphrase("Enter new passphrase (empty for no "
 837                             "passphrase): ", RP_ALLOW_STDIN);
 838                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 839                     RP_ALLOW_STDIN);
 840
 841                 /* Verify that they are the same. */
 842                 if (strcmp(passphrase1, passphrase2) != 0) {
 843                         memset(passphrase1, 0, strlen(passphrase1));
 844                         memset(passphrase2, 0, strlen(passphrase2));
 845                         xfree(passphrase1);
 846                         xfree(passphrase2);
 847                         printf("Pass phrases do not match.  Try again.\n");
 848                         exit(1);
 849                 }
 850                 /* Destroy the other copy. */
 851                 memset(passphrase2, 0, strlen(passphrase2));
 852                 xfree(passphrase2);
 853         }
 854
 855         /* Save the file using the new passphrase. */
 856         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 857                 printf("Saving the key failed: %s.\n", identity_file);
 858                 memset(passphrase1, 0, strlen(passphrase1));
 859                 xfree(passphrase1);
 860                 key_free(private);
 861                 xfree(comment);
 862                 exit(1);
 863         }
 864         /* Destroy the passphrase and the copy of the key in memory. */
 865         memset(passphrase1, 0, strlen(passphrase1));
 866         xfree(passphrase1);
 867         key_free(private);               /* Destroys contents */
 868         xfree(comment);
 869
 870         printf("Your identification has been saved with the new passphrase.\n");
 871         exit(0);
 872 }
 873
 874 /*
 875  * Print the SSHFP RR.
 876  */
 877 static int
 878 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 879 {
 880         Key *public;
 881         char *comment = NULL;
 882         struct stat st;
 883
 884         if (fname == NULL)
 885                 ask_filename(pw, "Enter file in which the key is");
 886         if (stat(fname, &st) < 0) {
 887                 if (errno == ENOENT)
 888                         return 0;
 889                 perror(fname);
 890                 exit(1);
 891         }
 892         public = key_load_public(fname, &comment);
 893         if (public != NULL) {
 894                 export_dns_rr(hname, public, stdout, print_generic);
 895                 key_free(public);
 896                 xfree(comment);
 897                 return 1;
 898         }
 899         if (comment)
 900                 xfree(comment);
 901
 902         printf("failed to read v2 public key from %s.\n", fname);
 903         exit(1);
 904 }
 905
 906 /*
 907  * Change the comment of a private key file.
 908  */
 909 static void
 910 do_change_comment(struct passwd *pw)
 911 {
 912         char new_comment[1024], *comment, *passphrase;
 913         Key *private;
 914         Key *public;
 915         struct stat st;
 916         FILE *f;
 917         int fd;
 918
 919         if (!have_identity)
 920                 ask_filename(pw, "Enter file in which the key is");
 921         if (stat(identity_file, &st) < 0) {
 922                 perror(identity_file);
 923                 exit(1);
 924         }
 925         private = key_load_private(identity_file, "", &comment);
 926         if (private == NULL) {
 927                 if (identity_passphrase)
 928                         passphrase = xstrdup(identity_passphrase);
 929                 else if (identity_new_passphrase)
 930                         passphrase = xstrdup(identity_new_passphrase);
 931                 else
 932                         passphrase = read_passphrase("Enter passphrase: ",
 933                             RP_ALLOW_STDIN);
 934                 /* Try to load using the passphrase. */
 935                 private = key_load_private(identity_file, passphrase, &comment);
 936                 if (private == NULL) {
 937                         memset(passphrase, 0, strlen(passphrase));
 938                         xfree(passphrase);
 939                         printf("Bad passphrase.\n");
 940                         exit(1);
 941                 }
 942         } else {
 943                 passphrase = xstrdup("");
 944         }
 945         if (private->type != KEY_RSA1) {
 946                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 947                 key_free(private);
 948                 exit(1);
 949         }
 950         printf("Key now has comment '%s'\n", comment);
 951
 952         if (identity_comment) {
 953                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 954         } else {
 955                 printf("Enter new comment: ");
 956                 fflush(stdout);
 957                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 958                         memset(passphrase, 0, strlen(passphrase));
 959                         key_free(private);
 960                         exit(1);
 961                 }
 962                 new_comment[strcspn(new_comment, "\n")] = '\0';
 963         }
 964
 965         /* Save the file using the new passphrase. */
 966         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 967                 printf("Saving the key failed: %s.\n", identity_file);
 968                 memset(passphrase, 0, strlen(passphrase));
 969                 xfree(passphrase);
 970                 key_free(private);
 971                 xfree(comment);
 972                 exit(1);
 973         }
 974         memset(passphrase, 0, strlen(passphrase));
 975         xfree(passphrase);
 976         public = key_from_private(private);
 977         key_free(private);
 978
 979         strlcat(identity_file, ".pub", sizeof(identity_file));
 980         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 981         if (fd == -1) {
 982                 printf("Could not save your public key in %s\n", identity_file);
 983                 exit(1);
 984         }
 985         f = fdopen(fd, "w");
 986         if (f == NULL) {
 987                 printf("fdopen %s failed", identity_file);
 988                 exit(1);
 989         }
 990         if (!key_write(public, f))
 991                 fprintf(stderr, "write key failed");
 992         key_free(public);
 993         fprintf(f, " %s\n", new_comment);
 994         fclose(f);
 995
 996         xfree(comment);
 997
 998         printf("The comment in your key file has been changed.\n");
 999         exit(0);
1000 }
1001
1002 static void
1003 usage(void)
1004 {
1005         fprintf(stderr, "usage: %s [options]\n", __progname);
1006         fprintf(stderr, "Options:\n");
1007         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1008         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1009         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1010         fprintf(stderr, "  -C comment  Provide new comment.\n");
1011         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1012 #ifdef SMARTCARD
1013         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1014 #endif /* SMARTCARD */
1015         fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
1016         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1017         fprintf(stderr, "  -f filename Filename of the key file.\n");
1018         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1019         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1020         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1021         fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
1022         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1023         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1024         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1025         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1026         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1027         fprintf(stderr, "  -q          Quiet.\n");
1028         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1029         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1030         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1031         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1032         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1033 #ifdef SMARTCARD
1034         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1035 #endif /* SMARTCARD */
1036         fprintf(stderr, "  -v          Verbose.\n");
1037         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1038         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1039
1040         exit(1);
1041 }
1042
1043 /*
1044  * Main program for key management.
1045  */
1046 int
1047 main(int argc, char **argv)
1048 {
1049         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1050         char out_file[MAXPATHLEN], *reader_id = NULL;
1051         char *rr_hostname = NULL;
1052         Key *private, *public;
1053         struct passwd *pw;
1054         struct stat st;
1055         int opt, type, fd, download = 0;
1056         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1057         int do_gen_candidates = 0, do_screen_candidates = 0;
1058         int log_level = SYSLOG_LEVEL_INFO;
1059         BIGNUM *start = NULL;
1060         FILE *f;
1061         const char *errstr;
1062
1063         extern int optind;
1064         extern char *optarg;
1065
1066         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1067         sanitise_stdfd();
1068
1069         __progname = ssh_get_progname(argv[0]);
1070
1071         SSLeay_add_all_algorithms();
1072         log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1073
1074         init_rng();
1075         seed_rng();
1076
1077         /* we need this for the home * directory.  */
1078         pw = getpwuid(getuid());
1079         if (!pw) {
1080                 printf("You don't exist, go away!\n");
1081                 exit(1);
1082         }
1083         if (gethostname(hostname, sizeof(hostname)) < 0) {
1084                 perror("gethostname");
1085                 exit(1);
1086         }
1087
1088         while ((opt = getopt(argc, argv,
1089             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1090                 switch (opt) {
1091                 case 'b':
1092                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1093                         if (errstr)
1094                                 fatal("Bits has bad value %s (%s)",
1095                                         optarg, errstr);
1096                         break;
1097                 case 'F':
1098                         find_host = 1;
1099                         rr_hostname = optarg;
1100                         break;
1101                 case 'H':
1102                         hash_hosts = 1;
1103                         break;
1104                 case 'R':
1105                         delete_host = 1;
1106                         rr_hostname = optarg;
1107                         break;
1108                 case 'l':
1109                         print_fingerprint = 1;
1110                         break;
1111                 case 'B':
1112                         print_bubblebabble = 1;
1113                         break;
1114                 case 'p':
1115                         change_passphrase = 1;
1116                         break;
1117                 case 'c':
1118                         change_comment = 1;
1119                         break;
1120                 case 'f':
1121                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1122                             sizeof(identity_file))
1123                                 fatal("Identity filename too long");
1124                         have_identity = 1;
1125                         break;
1126                 case 'g':
1127                         print_generic = 1;
1128                         break;
1129                 case 'P':
1130                         identity_passphrase = optarg;
1131                         break;
1132                 case 'N':
1133                         identity_new_passphrase = optarg;
1134                         break;
1135                 case 'C':
1136                         identity_comment = optarg;
1137                         break;
1138                 case 'q':
1139                         quiet = 1;
1140                         break;
1141                 case 'e':
1142                 case 'x':
1143                         /* export key */
1144                         convert_to_ssh2 = 1;
1145                         break;
1146                 case 'i':
1147                 case 'X':
1148                         /* import key */
1149                         convert_from_ssh2 = 1;
1150                         break;
1151                 case 'y':
1152                         print_public = 1;
1153                         break;
1154                 case 'd':
1155                         key_type_name = "dsa";
1156                         break;
1157                 case 't':
1158                         key_type_name = optarg;
1159                         break;
1160                 case 'D':
1161                         download = 1;
1162                         /*FALLTHROUGH*/
1163                 case 'U':
1164                         reader_id = optarg;
1165                         break;
1166                 case 'v':
1167                         if (log_level == SYSLOG_LEVEL_INFO)
1168                                 log_level = SYSLOG_LEVEL_DEBUG1;
1169                         else {
1170                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1171                                     log_level < SYSLOG_LEVEL_DEBUG3)
1172                                         log_level++;
1173                         }
1174                         break;
1175                 case 'r':
1176                         rr_hostname = optarg;
1177                         break;
1178                 case 'W':
1179                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1180                             UINT_MAX, &errstr);
1181                         if (errstr)
1182                                 fatal("Desired generator has bad value: %s (%s)",
1183                                         optarg, errstr);
1184                         break;
1185                 case 'a':
1186                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1187                         if (errstr)
1188                                 fatal("Invalid number of trials: %s (%s)",
1189                                         optarg, errstr);
1190                         break;
1191                 case 'M':
1192                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1193                         if (errstr) {
1194                                 fatal("Memory limit is %s: %s", errstr, optarg);
1195                         }
1196                         break;
1197                 case 'G':
1198                         do_gen_candidates = 1;
1199                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1200                             sizeof(out_file))
1201                                 fatal("Output filename too long");
1202                         break;
1203                 case 'T':
1204                         do_screen_candidates = 1;
1205                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1206                             sizeof(out_file))
1207                                 fatal("Output filename too long");
1208                         break;
1209                 case 'S':
1210                         /* XXX - also compare length against bits */
1211                         if (BN_hex2bn(&start, optarg) == 0)
1212                                 fatal("Invalid start point.");
1213                         break;
1214                 case '?':
1215                 default:
1216                         usage();
1217                 }
1218         }
1219
1220         /* reinit */
1221         log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
1222
1223         if (optind < argc) {
1224                 printf("Too many arguments.\n");
1225                 usage();
1226         }
1227         if (change_passphrase && change_comment) {
1228                 printf("Can only have one of -p and -c.\n");
1229                 usage();
1230         }
1231         if (delete_host || hash_hosts || find_host)
1232                 do_known_hosts(pw, rr_hostname);
1233         if (print_fingerprint || print_bubblebabble)
1234                 do_fingerprint(pw);
1235         if (change_passphrase)
1236                 do_change_passphrase(pw);
1237         if (change_comment)
1238                 do_change_comment(pw);
1239         if (convert_to_ssh2)
1240                 do_convert_to_ssh2(pw);
1241         if (convert_from_ssh2)
1242                 do_convert_from_ssh2(pw);
1243         if (print_public)
1244                 do_print_public(pw);
1245         if (rr_hostname != NULL) {
1246                 unsigned int n = 0;
1247
1248                 if (have_identity) {
1249                         n = do_print_resource_record(pw,
1250                             identity_file, rr_hostname);
1251                         if (n == 0) {
1252                                 perror(identity_file);
1253                                 exit(1);
1254                         }
1255                         exit(0);
1256                 } else {
1257
1258                         n += do_print_resource_record(pw,
1259                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1260                         n += do_print_resource_record(pw,
1261                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1262
1263                         if (n == 0)
1264                                 fatal("no keys found.");
1265                         exit(0);
1266                 }
1267         }
1268         if (reader_id != NULL) {
1269 #ifdef SMARTCARD
1270                 if (download)
1271                         do_download(pw, reader_id);
1272                 else
1273                         do_upload(pw, reader_id);
1274 #else /* SMARTCARD */
1275                 fatal("no support for smartcards.");
1276 #endif /* SMARTCARD */
1277         }
1278
1279         if (do_gen_candidates) {
1280                 FILE *out = fopen(out_file, "w");
1281
1282                 if (out == NULL) {
1283                         error("Couldn't open modulus candidate file \"%s\": %s",
1284                             out_file, strerror(errno));
1285                         return (1);
1286                 }
1287                 if (bits == 0)
1288                         bits = DEFAULT_BITS;
1289                 if (gen_candidates(out, memory, bits, start) != 0)
1290                         fatal("modulus candidate generation failed");
1291
1292                 return (0);
1293         }
1294
1295         if (do_screen_candidates) {
1296                 FILE *in;
1297                 FILE *out = fopen(out_file, "w");
1298
1299                 if (have_identity && strcmp(identity_file, "-") != 0) {
1300                         if ((in = fopen(identity_file, "r")) == NULL) {
1301                                 fatal("Couldn't open modulus candidate "
1302                                     "file \"%s\": %s", identity_file,
1303                                     strerror(errno));
1304                         }
1305                 } else
1306                         in = stdin;
1307
1308                 if (out == NULL) {
1309                         fatal("Couldn't open moduli file \"%s\": %s",
1310                             out_file, strerror(errno));
1311                 }
1312                 if (prime_test(in, out, trials, generator_wanted) != 0)
1313                         fatal("modulus screening failed");
1314                 return (0);
1315         }
1316
1317         arc4random_stir();
1318
1319         if (key_type_name == NULL)
1320                 key_type_name = "rsa";
1321
1322         type = key_type_from_name(key_type_name);
1323         if (type == KEY_UNSPEC) {
1324                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1325                 exit(1);
1326         }
1327         if (bits == 0)
1328                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1329         if (type == KEY_DSA && bits != 1024)
1330                 fatal("DSA keys must be 1024 bits");
1331         if (!quiet)
1332                 printf("Generating public/private %s key pair.\n", key_type_name);
1333         private = key_generate(type, bits);
1334         if (private == NULL) {
1335                 fprintf(stderr, "key_generate failed");
1336                 exit(1);
1337         }
1338         public  = key_from_private(private);
1339
1340         if (!have_identity)
1341                 ask_filename(pw, "Enter file in which to save the key");
1342
1343         /* Create ~/.ssh directory if it doesn't already exist. */
1344         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1345         if (strstr(identity_file, dotsshdir) != NULL &&
1346             stat(dotsshdir, &st) < 0) {
1347                 if (mkdir(dotsshdir, 0700) < 0)
1348                         error("Could not create directory '%s'.", dotsshdir);
1349                 else if (!quiet)
1350                         printf("Created directory '%s'.\n", dotsshdir);
1351         }
1352         /* If the file already exists, ask the user to confirm. */
1353         if (stat(identity_file, &st) >= 0) {
1354                 char yesno[3];
1355                 printf("%s already exists.\n", identity_file);
1356                 printf("Overwrite (y/n)? ");
1357                 fflush(stdout);
1358                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1359                         exit(1);
1360                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1361                         exit(1);
1362         }
1363         /* Ask for a passphrase (twice). */
1364         if (identity_passphrase)
1365                 passphrase1 = xstrdup(identity_passphrase);
1366         else if (identity_new_passphrase)
1367                 passphrase1 = xstrdup(identity_new_passphrase);
1368         else {
1369 passphrase_again:
1370                 passphrase1 =
1371                         read_passphrase("Enter passphrase (empty for no "
1372                             "passphrase): ", RP_ALLOW_STDIN);
1373                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1374                     RP_ALLOW_STDIN);
1375                 if (strcmp(passphrase1, passphrase2) != 0) {
1376                         /*
1377                          * The passphrases do not match.  Clear them and
1378                          * retry.
1379                          */
1380                         memset(passphrase1, 0, strlen(passphrase1));
1381                         memset(passphrase2, 0, strlen(passphrase2));
1382                         xfree(passphrase1);
1383                         xfree(passphrase2);
1384                         printf("Passphrases do not match.  Try again.\n");
1385                         goto passphrase_again;
1386                 }
1387                 /* Clear the other copy of the passphrase. */
1388                 memset(passphrase2, 0, strlen(passphrase2));
1389                 xfree(passphrase2);
1390         }
1391
1392         if (identity_comment) {
1393                 strlcpy(comment, identity_comment, sizeof(comment));
1394         } else {
1395                 /* Create default commend field for the passphrase. */
1396                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1397         }
1398
1399         /* Save the key with the given passphrase and comment. */
1400         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1401                 printf("Saving the key failed: %s.\n", identity_file);
1402                 memset(passphrase1, 0, strlen(passphrase1));
1403                 xfree(passphrase1);
1404                 exit(1);
1405         }
1406         /* Clear the passphrase. */
1407         memset(passphrase1, 0, strlen(passphrase1));
1408         xfree(passphrase1);
1409
1410         /* Clear the private key and the random number generator. */
1411         key_free(private);
1412         arc4random_stir();
1413
1414         if (!quiet)
1415                 printf("Your identification has been saved in %s.\n", identity_file);
1416
1417         strlcat(identity_file, ".pub", sizeof(identity_file));
1418         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1419         if (fd == -1) {
1420                 printf("Could not save your public key in %s\n", identity_file);
1421                 exit(1);
1422         }
1423         f = fdopen(fd, "w");
1424         if (f == NULL) {
1425                 printf("fdopen %s failed", identity_file);
1426                 exit(1);
1427         }
1428         if (!key_write(public, f))
1429                 fprintf(stderr, "write key failed");
1430         fprintf(f, " %s\n", comment);
1431         fclose(f);
1432
1433         if (!quiet) {
1434                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1435                 printf("Your public key has been saved in %s.\n",
1436                     identity_file);
1437                 printf("The key fingerprint is:\n");
1438                 printf("%s %s\n", fp, comment);
1439                 xfree(fp);
1440         }
1441
1442         key_free(public);
1443         exit(0);
1444 }