ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.151 2006/07/26 02:35:17 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 #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 <string.h>
  33 #include <unistd.h>
  34
  35 #include "xmalloc.h"
  36 #include "key.h"
  37 #include "rsa.h"
  38 #include "authfile.h"
  39 #include "uuencode.h"
  40 #include "buffer.h"
  41 #include "bufaux.h"
  42 #include "pathnames.h"
  43 #include "log.h"
  44 #include "misc.h"
  45 #include "match.h"
  46 #include "hostfile.h"
  47 #include "dns.h"
  48
  49 #ifdef SMARTCARD
  50 #include "scard.h"
  51 #endif
  52
  53 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  54 #define DEFAULT_BITS            2048
  55 #define DEFAULT_BITS_DSA        1024
  56 u_int32_t bits = 0;
  57
  58 /*
  59  * Flag indicating that we just want to change the passphrase.  This can be
  60  * set on the command line.
  61  */
  62 int change_passphrase = 0;
  63
  64 /*
  65  * Flag indicating that we just want to change the comment.  This can be set
  66  * on the command line.
  67  */
  68 int change_comment = 0;
  69
  70 int quiet = 0;
  71
  72 /* Flag indicating that we want to hash a known_hosts file */
  73 int hash_hosts = 0;
  74 /* Flag indicating that we want lookup a host in known_hosts file */
  75 int find_host = 0;
  76 /* Flag indicating that we want to delete a host from a known_hosts file */
  77 int delete_host = 0;
  78
  79 /* Flag indicating that we just want to see the key fingerprint */
  80 int print_fingerprint = 0;
  81 int print_bubblebabble = 0;
  82
  83 /* The identity file name, given on the command line or entered by the user. */
  84 char identity_file[1024];
  85 int have_identity = 0;
  86
  87 /* This is set to the passphrase if given on the command line. */
  88 char *identity_passphrase = NULL;
  89
  90 /* This is set to the new passphrase if given on the command line. */
  91 char *identity_new_passphrase = NULL;
  92
  93 /* This is set to the new comment if given on the command line. */
  94 char *identity_comment = NULL;
  95
  96 /* Dump public key file in format used by real and the original SSH 2 */
  97 int convert_to_ssh2 = 0;
  98 int convert_from_ssh2 = 0;
  99 int print_public = 0;
 100 int print_generic = 0;
 101
 102 char *key_type_name = NULL;
 103
 104 /* argv0 */
 105 extern char *__progname;
 106
 107 char hostname[MAXHOSTNAMELEN];
 108
 109 /* moduli.c */
 110 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 111 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 112
 113 static void
 114 ask_filename(struct passwd *pw, const char *prompt)
 115 {
 116         char buf[1024];
 117         char *name = NULL;
 118
 119         if (key_type_name == NULL)
 120                 name = _PATH_SSH_CLIENT_ID_RSA;
 121         else {
 122                 switch (key_type_from_name(key_type_name)) {
 123                 case KEY_RSA1:
 124                         name = _PATH_SSH_CLIENT_IDENTITY;
 125                         break;
 126                 case KEY_DSA:
 127                         name = _PATH_SSH_CLIENT_ID_DSA;
 128                         break;
 129                 case KEY_RSA:
 130                         name = _PATH_SSH_CLIENT_ID_RSA;
 131                         break;
 132                 default:
 133                         fprintf(stderr, "bad key type");
 134                         exit(1);
 135                         break;
 136                 }
 137         }
 138         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 139         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 140         if (fgets(buf, sizeof(buf), stdin) == NULL)
 141                 exit(1);
 142         if (strchr(buf, '\n'))
 143                 *strchr(buf, '\n') = 0;
 144         if (strcmp(buf, "") != 0)
 145                 strlcpy(identity_file, buf, sizeof(identity_file));
 146         have_identity = 1;
 147 }
 148
 149 static Key *
 150 load_identity(char *filename)
 151 {
 152         char *pass;
 153         Key *prv;
 154
 155         prv = key_load_private(filename, "", NULL);
 156         if (prv == NULL) {
 157                 if (identity_passphrase)
 158                         pass = xstrdup(identity_passphrase);
 159                 else
 160                         pass = read_passphrase("Enter passphrase: ",
 161                             RP_ALLOW_STDIN);
 162                 prv = key_load_private(filename, pass, NULL);
 163                 memset(pass, 0, strlen(pass));
 164                 xfree(pass);
 165         }
 166         return prv;
 167 }
 168
 169 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 170 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 171 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 172 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 173
 174 static void
 175 do_convert_to_ssh2(struct passwd *pw)
 176 {
 177         Key *k;
 178         u_int len;
 179         u_char *blob;
 180         struct stat st;
 181
 182         if (!have_identity)
 183                 ask_filename(pw, "Enter file in which the key is");
 184         if (stat(identity_file, &st) < 0) {
 185                 perror(identity_file);
 186                 exit(1);
 187         }
 188         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 189                 if ((k = load_identity(identity_file)) == NULL) {
 190                         fprintf(stderr, "load failed\n");
 191                         exit(1);
 192                 }
 193         }
 194         if (k->type == KEY_RSA1) {
 195                 fprintf(stderr, "version 1 keys are not supported\n");
 196                 exit(1);
 197         }
 198         if (key_to_blob(k, &blob, &len) <= 0) {
 199                 fprintf(stderr, "key_to_blob failed\n");
 200                 exit(1);
 201         }
 202         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 203         fprintf(stdout,
 204             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 205             key_size(k), key_type(k),
 206             pw->pw_name, hostname);
 207         dump_base64(stdout, blob, len);
 208         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 209         key_free(k);
 210         xfree(blob);
 211         exit(0);
 212 }
 213
 214 static void
 215 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 216 {
 217         u_int bignum_bits = buffer_get_int(b);
 218         u_int bytes = (bignum_bits + 7) / 8;
 219
 220         if (buffer_len(b) < bytes)
 221                 fatal("buffer_get_bignum_bits: input buffer too small: "
 222                     "need %d have %d", bytes, buffer_len(b));
 223         BN_bin2bn(buffer_ptr(b), bytes, value);
 224         buffer_consume(b, bytes);
 225 }
 226
 227 static Key *
 228 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 229 {
 230         Buffer b;
 231         Key *key = NULL;
 232         char *type, *cipher;
 233         u_char *sig, data[] = "abcde12345";
 234         int magic, rlen, ktype, i1, i2, i3, i4;
 235         u_int slen;
 236         u_long e;
 237
 238         buffer_init(&b);
 239         buffer_append(&b, blob, blen);
 240
 241         magic  = buffer_get_int(&b);
 242         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 243                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 244                 buffer_free(&b);
 245                 return NULL;
 246         }
 247         i1 = buffer_get_int(&b);
 248         type   = buffer_get_string(&b, NULL);
 249         cipher = buffer_get_string(&b, NULL);
 250         i2 = buffer_get_int(&b);
 251         i3 = buffer_get_int(&b);
 252         i4 = buffer_get_int(&b);
 253         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 254         if (strcmp(cipher, "none") != 0) {
 255                 error("unsupported cipher %s", cipher);
 256                 xfree(cipher);
 257                 buffer_free(&b);
 258                 xfree(type);
 259                 return NULL;
 260         }
 261         xfree(cipher);
 262
 263         if (strstr(type, "dsa")) {
 264                 ktype = KEY_DSA;
 265         } else if (strstr(type, "rsa")) {
 266                 ktype = KEY_RSA;
 267         } else {
 268                 buffer_free(&b);
 269                 xfree(type);
 270                 return NULL;
 271         }
 272         key = key_new_private(ktype);
 273         xfree(type);
 274
 275         switch (key->type) {
 276         case KEY_DSA:
 277                 buffer_get_bignum_bits(&b, key->dsa->p);
 278                 buffer_get_bignum_bits(&b, key->dsa->g);
 279                 buffer_get_bignum_bits(&b, key->dsa->q);
 280                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 281                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 282                 break;
 283         case KEY_RSA:
 284                 e  = buffer_get_char(&b);
 285                 debug("e %lx", e);
 286                 if (e < 30) {
 287                         e <<= 8;
 288                         e += buffer_get_char(&b);
 289                         debug("e %lx", e);
 290                         e <<= 8;
 291                         e += buffer_get_char(&b);
 292                         debug("e %lx", e);
 293                 }
 294                 if (!BN_set_word(key->rsa->e, e)) {
 295                         buffer_free(&b);
 296                         key_free(key);
 297                         return NULL;
 298                 }
 299                 buffer_get_bignum_bits(&b, key->rsa->d);
 300                 buffer_get_bignum_bits(&b, key->rsa->n);
 301                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 302                 buffer_get_bignum_bits(&b, key->rsa->q);
 303                 buffer_get_bignum_bits(&b, key->rsa->p);
 304                 rsa_generate_additional_parameters(key->rsa);
 305                 break;
 306         }
 307         rlen = buffer_len(&b);
 308         if (rlen != 0)
 309                 error("do_convert_private_ssh2_from_blob: "
 310                     "remaining bytes in key blob %d", rlen);
 311         buffer_free(&b);
 312
 313         /* try the key */
 314         key_sign(key, &sig, &slen, data, sizeof(data));
 315         key_verify(key, sig, slen, data, sizeof(data));
 316         xfree(sig);
 317         return key;
 318 }
 319
 320 static int
 321 get_line(FILE *fp, char *line, size_t len)
 322 {
 323         int c;
 324         size_t pos = 0;
 325
 326         line[0] = '\0';
 327         while ((c = fgetc(fp)) != EOF) {
 328                 if (pos >= len - 1) {
 329                         fprintf(stderr, "input line too long.\n");
 330                         exit(1);
 331                 }
 332                 switch (c) {
 333                 case '\r':
 334                         c = fgetc(fp);
 335                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 336                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 337                                 exit(1);
 338                         }
 339                         return pos;
 340                 case '\n':
 341                         return pos;
 342                 }
 343                 line[pos++] = c;
 344                 line[pos] = '\0';
 345         }
 346         if (c == EOF)
 347                 return -1;
 348         return pos;
 349 }
 350
 351 static void
 352 do_convert_from_ssh2(struct passwd *pw)
 353 {
 354         Key *k;
 355         int blen;
 356         u_int len;
 357         char line[1024];
 358         u_char blob[8096];
 359         char encoded[8096];
 360         struct stat st;
 361         int escaped = 0, private = 0, ok;
 362         FILE *fp;
 363
 364         if (!have_identity)
 365                 ask_filename(pw, "Enter file in which the key is");
 366         if (stat(identity_file, &st) < 0) {
 367                 perror(identity_file);
 368                 exit(1);
 369         }
 370         fp = fopen(identity_file, "r");
 371         if (fp == NULL) {
 372                 perror(identity_file);
 373                 exit(1);
 374         }
 375         encoded[0] = '\0';
 376         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 377                 if (line[blen - 1] == '\\')
 378                         escaped++;
 379                 if (strncmp(line, "----", 4) == 0 ||
 380                     strstr(line, ": ") != NULL) {
 381                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 382                                 private = 1;
 383                         if (strstr(line, " END ") != NULL) {
 384                                 break;
 385                         }
 386                         /* fprintf(stderr, "ignore: %s", line); */
 387                         continue;
 388                 }
 389                 if (escaped) {
 390                         escaped--;
 391                         /* fprintf(stderr, "escaped: %s", line); */
 392                         continue;
 393                 }
 394                 strlcat(encoded, line, sizeof(encoded));
 395         }
 396         len = strlen(encoded);
 397         if (((len % 4) == 3) &&
 398             (encoded[len-1] == '=') &&
 399             (encoded[len-2] == '=') &&
 400             (encoded[len-3] == '='))
 401                 encoded[len-3] = '\0';
 402         blen = uudecode(encoded, blob, sizeof(blob));
 403         if (blen < 0) {
 404                 fprintf(stderr, "uudecode failed.\n");
 405                 exit(1);
 406         }
 407         k = private ?
 408             do_convert_private_ssh2_from_blob(blob, blen) :
 409             key_from_blob(blob, blen);
 410         if (k == NULL) {
 411                 fprintf(stderr, "decode blob failed.\n");
 412                 exit(1);
 413         }
 414         ok = private ?
 415             (k->type == KEY_DSA ?
 416                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 417                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 418             key_write(k, stdout);
 419         if (!ok) {
 420                 fprintf(stderr, "key write failed");
 421                 exit(1);
 422         }
 423         key_free(k);
 424         if (!private)
 425                 fprintf(stdout, "\n");
 426         fclose(fp);
 427         exit(0);
 428 }
 429
 430 static void
 431 do_print_public(struct passwd *pw)
 432 {
 433         Key *prv;
 434         struct stat st;
 435
 436         if (!have_identity)
 437                 ask_filename(pw, "Enter file in which the key is");
 438         if (stat(identity_file, &st) < 0) {
 439                 perror(identity_file);
 440                 exit(1);
 441         }
 442         prv = load_identity(identity_file);
 443         if (prv == NULL) {
 444                 fprintf(stderr, "load failed\n");
 445                 exit(1);
 446         }
 447         if (!key_write(prv, stdout))
 448                 fprintf(stderr, "key_write failed");
 449         key_free(prv);
 450         fprintf(stdout, "\n");
 451         exit(0);
 452 }
 453
 454 #ifdef SMARTCARD
 455 static void
 456 do_upload(struct passwd *pw, const char *sc_reader_id)
 457 {
 458         Key *prv = NULL;
 459         struct stat st;
 460         int ret;
 461
 462         if (!have_identity)
 463                 ask_filename(pw, "Enter file in which the key is");
 464         if (stat(identity_file, &st) < 0) {
 465                 perror(identity_file);
 466                 exit(1);
 467         }
 468         prv = load_identity(identity_file);
 469         if (prv == NULL) {
 470                 error("load failed");
 471                 exit(1);
 472         }
 473         ret = sc_put_key(prv, sc_reader_id);
 474         key_free(prv);
 475         if (ret < 0)
 476                 exit(1);
 477         logit("loading key done");
 478         exit(0);
 479 }
 480
 481 static void
 482 do_download(struct passwd *pw, const char *sc_reader_id)
 483 {
 484         Key **keys = NULL;
 485         int i;
 486
 487         keys = sc_get_keys(sc_reader_id, NULL);
 488         if (keys == NULL)
 489                 fatal("cannot read public key from smartcard");
 490         for (i = 0; keys[i]; i++) {
 491                 key_write(keys[i], stdout);
 492                 key_free(keys[i]);
 493                 fprintf(stdout, "\n");
 494         }
 495         xfree(keys);
 496         exit(0);
 497 }
 498 #endif /* SMARTCARD */
 499
 500 static void
 501 do_fingerprint(struct passwd *pw)
 502 {
 503         FILE *f;
 504         Key *public;
 505         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 506         int i, skip = 0, num = 1, invalid = 1;
 507         enum fp_rep rep;
 508         enum fp_type fptype;
 509         struct stat st;
 510
 511         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 512         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 513
 514         if (!have_identity)
 515                 ask_filename(pw, "Enter file in which the key is");
 516         if (stat(identity_file, &st) < 0) {
 517                 perror(identity_file);
 518                 exit(1);
 519         }
 520         public = key_load_public(identity_file, &comment);
 521         if (public != NULL) {
 522                 fp = key_fingerprint(public, fptype, rep);
 523                 printf("%u %s %s\n", key_size(public), fp, comment);
 524                 key_free(public);
 525                 xfree(comment);
 526                 xfree(fp);
 527                 exit(0);
 528         }
 529         if (comment) {
 530                 xfree(comment);
 531                 comment = NULL;
 532         }
 533
 534         f = fopen(identity_file, "r");
 535         if (f != NULL) {
 536                 while (fgets(line, sizeof(line), f)) {
 537                         i = strlen(line) - 1;
 538                         if (line[i] != '\n') {
 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                         line[i] = '\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, i, skip = 0, inplace = 0, num = 0, 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                 num++;
 652                 i = strlen(line) - 1;
 653                 if (line[i] != '\n') {
 654                         error("line %d too long: %.40s...", num, line);
 655                         skip = 1;
 656                         invalid = 1;
 657                         continue;
 658                 }
 659                 if (skip) {
 660                         skip = 0;
 661                         continue;
 662                 }
 663                 line[i] = '\0';
 664
 665                 /* Skip leading whitespace, empty and comment lines. */
 666                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 667                         ;
 668                 if (!*cp || *cp == '\n' || *cp == '#') {
 669                         if (inplace)
 670                                 fprintf(out, "%s\n", cp);
 671                         continue;
 672                 }
 673                 /* Find the end of the host name portion. */
 674                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 675                         ;
 676                 if (*kp == '\0' || *(kp + 1) == '\0') {
 677                         error("line %d missing key: %.40s...",
 678                             num, line);
 679                         invalid = 1;
 680                         continue;
 681                 }
 682                 *kp++ = '\0';
 683                 kp2 = kp;
 684
 685                 public = key_new(KEY_RSA1);
 686                 if (key_read(public, &kp) != 1) {
 687                         kp = kp2;
 688                         key_free(public);
 689                         public = key_new(KEY_UNSPEC);
 690                         if (key_read(public, &kp) != 1) {
 691                                 error("line %d invalid key: %.40s...",
 692                                     num, line);
 693                                 key_free(public);
 694                                 invalid = 1;
 695                                 continue;
 696                         }
 697                 }
 698
 699                 if (*cp == HASH_DELIM) {
 700                         if (find_host || delete_host) {
 701                                 cp2 = host_hash(name, cp, strlen(cp));
 702                                 if (cp2 == NULL) {
 703                                         error("line %d: invalid hashed "
 704                                             "name: %.64s...", num, line);
 705                                         invalid = 1;
 706                                         continue;
 707                                 }
 708                                 c = (strcmp(cp2, cp) == 0);
 709                                 if (find_host && c) {
 710                                         printf("# Host %s found: "
 711                                             "line %d type %s\n", name,
 712                                             num, key_type(public));
 713                                         print_host(out, cp, public, 0);
 714                                 }
 715                                 if (delete_host && !c)
 716                                         print_host(out, cp, public, 0);
 717                         } else if (hash_hosts)
 718                                 print_host(out, cp, public, 0);
 719                 } else {
 720                         if (find_host || delete_host) {
 721                                 c = (match_hostname(name, cp,
 722                                     strlen(cp)) == 1);
 723                                 if (find_host && c) {
 724                                         printf("# Host %s found: "
 725                                             "line %d type %s\n", name,
 726                                             num, key_type(public));
 727                                         print_host(out, cp, public, hash_hosts);
 728                                 }
 729                                 if (delete_host && !c)
 730                                         print_host(out, cp, public, 0);
 731                         } else if (hash_hosts) {
 732                                 for (cp2 = strsep(&cp, ",");
 733                                     cp2 != NULL && *cp2 != '\0';
 734                                     cp2 = strsep(&cp, ",")) {
 735                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 736                                                 fprintf(stderr, "Warning: "
 737                                                     "ignoring host name with "
 738                                                     "metacharacters: %.64s\n",
 739                                                     cp2);
 740                                         else
 741                                                 print_host(out, cp2, public, 1);
 742                                 }
 743                                 has_unhashed = 1;
 744                         }
 745                 }
 746                 key_free(public);
 747         }
 748         fclose(in);
 749
 750         if (invalid) {
 751                 fprintf(stderr, "%s is not a valid known_host file.\n",
 752                     identity_file);
 753                 if (inplace) {
 754                         fprintf(stderr, "Not replacing existing known_hosts "
 755                             "file because of errors\n");
 756                         fclose(out);
 757                         unlink(tmp);
 758                 }
 759                 exit(1);
 760         }
 761
 762         if (inplace) {
 763                 fclose(out);
 764
 765                 /* Backup existing file */
 766                 if (unlink(old) == -1 && errno != ENOENT)
 767                         fatal("unlink %.100s: %s", old, strerror(errno));
 768                 if (link(identity_file, old) == -1)
 769                         fatal("link %.100s to %.100s: %s", identity_file, old,
 770                             strerror(errno));
 771                 /* Move new one into place */
 772                 if (rename(tmp, identity_file) == -1) {
 773                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 774                             strerror(errno));
 775                         unlink(tmp);
 776                         unlink(old);
 777                         exit(1);
 778                 }
 779
 780                 fprintf(stderr, "%s updated.\n", identity_file);
 781                 fprintf(stderr, "Original contents retained as %s\n", old);
 782                 if (has_unhashed) {
 783                         fprintf(stderr, "WARNING: %s contains unhashed "
 784                             "entries\n", old);
 785                         fprintf(stderr, "Delete this file to ensure privacy "
 786                             "of hostnames\n");
 787                 }
 788         }
 789
 790         exit(0);
 791 }
 792
 793 /*
 794  * Perform changing a passphrase.  The argument is the passwd structure
 795  * for the current user.
 796  */
 797 static void
 798 do_change_passphrase(struct passwd *pw)
 799 {
 800         char *comment;
 801         char *old_passphrase, *passphrase1, *passphrase2;
 802         struct stat st;
 803         Key *private;
 804
 805         if (!have_identity)
 806                 ask_filename(pw, "Enter file in which the key is");
 807         if (stat(identity_file, &st) < 0) {
 808                 perror(identity_file);
 809                 exit(1);
 810         }
 811         /* Try to load the file with empty passphrase. */
 812         private = key_load_private(identity_file, "", &comment);
 813         if (private == NULL) {
 814                 if (identity_passphrase)
 815                         old_passphrase = xstrdup(identity_passphrase);
 816                 else
 817                         old_passphrase =
 818                             read_passphrase("Enter old passphrase: ",
 819                             RP_ALLOW_STDIN);
 820                 private = key_load_private(identity_file, old_passphrase,
 821                     &comment);
 822                 memset(old_passphrase, 0, strlen(old_passphrase));
 823                 xfree(old_passphrase);
 824                 if (private == NULL) {
 825                         printf("Bad passphrase.\n");
 826                         exit(1);
 827                 }
 828         }
 829         printf("Key has comment '%s'\n", comment);
 830
 831         /* Ask the new passphrase (twice). */
 832         if (identity_new_passphrase) {
 833                 passphrase1 = xstrdup(identity_new_passphrase);
 834                 passphrase2 = NULL;
 835         } else {
 836                 passphrase1 =
 837                         read_passphrase("Enter new passphrase (empty for no "
 838                             "passphrase): ", RP_ALLOW_STDIN);
 839                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 840                     RP_ALLOW_STDIN);
 841
 842                 /* Verify that they are the same. */
 843                 if (strcmp(passphrase1, passphrase2) != 0) {
 844                         memset(passphrase1, 0, strlen(passphrase1));
 845                         memset(passphrase2, 0, strlen(passphrase2));
 846                         xfree(passphrase1);
 847                         xfree(passphrase2);
 848                         printf("Pass phrases do not match.  Try again.\n");
 849                         exit(1);
 850                 }
 851                 /* Destroy the other copy. */
 852                 memset(passphrase2, 0, strlen(passphrase2));
 853                 xfree(passphrase2);
 854         }
 855
 856         /* Save the file using the new passphrase. */
 857         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 858                 printf("Saving the key failed: %s.\n", identity_file);
 859                 memset(passphrase1, 0, strlen(passphrase1));
 860                 xfree(passphrase1);
 861                 key_free(private);
 862                 xfree(comment);
 863                 exit(1);
 864         }
 865         /* Destroy the passphrase and the copy of the key in memory. */
 866         memset(passphrase1, 0, strlen(passphrase1));
 867         xfree(passphrase1);
 868         key_free(private);               /* Destroys contents */
 869         xfree(comment);
 870
 871         printf("Your identification has been saved with the new passphrase.\n");
 872         exit(0);
 873 }
 874
 875 /*
 876  * Print the SSHFP RR.
 877  */
 878 static int
 879 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 880 {
 881         Key *public;
 882         char *comment = NULL;
 883         struct stat st;
 884
 885         if (fname == NULL)
 886                 ask_filename(pw, "Enter file in which the key is");
 887         if (stat(fname, &st) < 0) {
 888                 if (errno == ENOENT)
 889                         return 0;
 890                 perror(fname);
 891                 exit(1);
 892         }
 893         public = key_load_public(fname, &comment);
 894         if (public != NULL) {
 895                 export_dns_rr(hname, public, stdout, print_generic);
 896                 key_free(public);
 897                 xfree(comment);
 898                 return 1;
 899         }
 900         if (comment)
 901                 xfree(comment);
 902
 903         printf("failed to read v2 public key from %s.\n", fname);
 904         exit(1);
 905 }
 906
 907 /*
 908  * Change the comment of a private key file.
 909  */
 910 static void
 911 do_change_comment(struct passwd *pw)
 912 {
 913         char new_comment[1024], *comment, *passphrase;
 914         Key *private;
 915         Key *public;
 916         struct stat st;
 917         FILE *f;
 918         int fd;
 919
 920         if (!have_identity)
 921                 ask_filename(pw, "Enter file in which the key is");
 922         if (stat(identity_file, &st) < 0) {
 923                 perror(identity_file);
 924                 exit(1);
 925         }
 926         private = key_load_private(identity_file, "", &comment);
 927         if (private == NULL) {
 928                 if (identity_passphrase)
 929                         passphrase = xstrdup(identity_passphrase);
 930                 else if (identity_new_passphrase)
 931                         passphrase = xstrdup(identity_new_passphrase);
 932                 else
 933                         passphrase = read_passphrase("Enter passphrase: ",
 934                             RP_ALLOW_STDIN);
 935                 /* Try to load using the passphrase. */
 936                 private = key_load_private(identity_file, passphrase, &comment);
 937                 if (private == NULL) {
 938                         memset(passphrase, 0, strlen(passphrase));
 939                         xfree(passphrase);
 940                         printf("Bad passphrase.\n");
 941                         exit(1);
 942                 }
 943         } else {
 944                 passphrase = xstrdup("");
 945         }
 946         if (private->type != KEY_RSA1) {
 947                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 948                 key_free(private);
 949                 exit(1);
 950         }
 951         printf("Key now has comment '%s'\n", comment);
 952
 953         if (identity_comment) {
 954                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 955         } else {
 956                 printf("Enter new comment: ");
 957                 fflush(stdout);
 958                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 959                         memset(passphrase, 0, strlen(passphrase));
 960                         key_free(private);
 961                         exit(1);
 962                 }
 963                 if (strchr(new_comment, '\n'))
 964                         *strchr(new_comment, '\n') = 0;
 965         }
 966
 967         /* Save the file using the new passphrase. */
 968         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 969                 printf("Saving the key failed: %s.\n", identity_file);
 970                 memset(passphrase, 0, strlen(passphrase));
 971                 xfree(passphrase);
 972                 key_free(private);
 973                 xfree(comment);
 974                 exit(1);
 975         }
 976         memset(passphrase, 0, strlen(passphrase));
 977         xfree(passphrase);
 978         public = key_from_private(private);
 979         key_free(private);
 980
 981         strlcat(identity_file, ".pub", sizeof(identity_file));
 982         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 983         if (fd == -1) {
 984                 printf("Could not save your public key in %s\n", identity_file);
 985                 exit(1);
 986         }
 987         f = fdopen(fd, "w");
 988         if (f == NULL) {
 989                 printf("fdopen %s failed", identity_file);
 990                 exit(1);
 991         }
 992         if (!key_write(public, f))
 993                 fprintf(stderr, "write key failed");
 994         key_free(public);
 995         fprintf(f, " %s\n", new_comment);
 996         fclose(f);
 997
 998         xfree(comment);
 999
1000         printf("The comment in your key file has been changed.\n");
1001         exit(0);
1002 }
1003
1004 static void
1005 usage(void)
1006 {
1007         fprintf(stderr, "Usage: %s [options]\n", __progname);
1008         fprintf(stderr, "Options:\n");
1009         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1010         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1011         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1012         fprintf(stderr, "  -C comment  Provide new comment.\n");
1013         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1014 #ifdef SMARTCARD
1015         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1016 #endif /* SMARTCARD */
1017         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1018         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1019         fprintf(stderr, "  -f filename Filename of the key file.\n");
1020         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1021         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1022         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1023         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1024         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1025         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1026         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1027         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1028         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1029         fprintf(stderr, "  -q          Quiet.\n");
1030         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1031         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1032         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1033         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1034         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1035 #ifdef SMARTCARD
1036         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1037 #endif /* SMARTCARD */
1038         fprintf(stderr, "  -v          Verbose.\n");
1039         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1040         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1041
1042         exit(1);
1043 }
1044
1045 /*
1046  * Main program for key management.
1047  */
1048 int
1049 main(int ac, char **av)
1050 {
1051         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1052         char out_file[MAXPATHLEN], *reader_id = NULL;
1053         char *rr_hostname = NULL;
1054         Key *private, *public;
1055         struct passwd *pw;
1056         struct stat st;
1057         int opt, type, fd, download = 0;
1058         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1059         int do_gen_candidates = 0, do_screen_candidates = 0;
1060         int log_level = SYSLOG_LEVEL_INFO;
1061         BIGNUM *start = NULL;
1062         FILE *f;
1063         const char *errstr;
1064
1065         extern int optind;
1066         extern char *optarg;
1067
1068         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1069         sanitise_stdfd();
1070
1071         __progname = ssh_get_progname(av[0]);
1072
1073         SSLeay_add_all_algorithms();
1074         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1075
1076         init_rng();
1077         seed_rng();
1078
1079         /* we need this for the home * directory.  */
1080         pw = getpwuid(getuid());
1081         if (!pw) {
1082                 printf("You don't exist, go away!\n");
1083                 exit(1);
1084         }
1085         if (gethostname(hostname, sizeof(hostname)) < 0) {
1086                 perror("gethostname");
1087                 exit(1);
1088         }
1089
1090         while ((opt = getopt(ac, av,
1091             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1092                 switch (opt) {
1093                 case 'b':
1094                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1095                         if (errstr)
1096                                 fatal("Bits has bad value %s (%s)",
1097                                         optarg, errstr);
1098                         break;
1099                 case 'F':
1100                         find_host = 1;
1101                         rr_hostname = optarg;
1102                         break;
1103                 case 'H':
1104                         hash_hosts = 1;
1105                         break;
1106                 case 'R':
1107                         delete_host = 1;
1108                         rr_hostname = optarg;
1109                         break;
1110                 case 'l':
1111                         print_fingerprint = 1;
1112                         break;
1113                 case 'B':
1114                         print_bubblebabble = 1;
1115                         break;
1116                 case 'p':
1117                         change_passphrase = 1;
1118                         break;
1119                 case 'c':
1120                         change_comment = 1;
1121                         break;
1122                 case 'f':
1123                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1124                             sizeof(identity_file))
1125                                 fatal("Identity filename too long");
1126                         have_identity = 1;
1127                         break;
1128                 case 'g':
1129                         print_generic = 1;
1130                         break;
1131                 case 'P':
1132                         identity_passphrase = optarg;
1133                         break;
1134                 case 'N':
1135                         identity_new_passphrase = optarg;
1136                         break;
1137                 case 'C':
1138                         identity_comment = optarg;
1139                         break;
1140                 case 'q':
1141                         quiet = 1;
1142                         break;
1143                 case 'e':
1144                 case 'x':
1145                         /* export key */
1146                         convert_to_ssh2 = 1;
1147                         break;
1148                 case 'i':
1149                 case 'X':
1150                         /* import key */
1151                         convert_from_ssh2 = 1;
1152                         break;
1153                 case 'y':
1154                         print_public = 1;
1155                         break;
1156                 case 'd':
1157                         key_type_name = "dsa";
1158                         break;
1159                 case 't':
1160                         key_type_name = optarg;
1161                         break;
1162                 case 'D':
1163                         download = 1;
1164                         /*FALLTHROUGH*/
1165                 case 'U':
1166                         reader_id = optarg;
1167                         break;
1168                 case 'v':
1169                         if (log_level == SYSLOG_LEVEL_INFO)
1170                                 log_level = SYSLOG_LEVEL_DEBUG1;
1171                         else {
1172                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1173                                     log_level < SYSLOG_LEVEL_DEBUG3)
1174                                         log_level++;
1175                         }
1176                         break;
1177                 case 'r':
1178                         rr_hostname = optarg;
1179                         break;
1180                 case 'W':
1181                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1182                             UINT_MAX, &errstr);
1183                         if (errstr)
1184                                 fatal("Desired generator has bad value: %s (%s)",
1185                                         optarg, errstr);
1186                         break;
1187                 case 'a':
1188                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1189                         if (errstr)
1190                                 fatal("Invalid number of trials: %s (%s)",
1191                                         optarg, errstr);
1192                         break;
1193                 case 'M':
1194                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1195                         if (errstr) {
1196                                 fatal("Memory limit is %s: %s", errstr, optarg);
1197                         }
1198                         break;
1199                 case 'G':
1200                         do_gen_candidates = 1;
1201                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1202                             sizeof(out_file))
1203                                 fatal("Output filename too long");
1204                         break;
1205                 case 'T':
1206                         do_screen_candidates = 1;
1207                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1208                             sizeof(out_file))
1209                                 fatal("Output filename too long");
1210                         break;
1211                 case 'S':
1212                         /* XXX - also compare length against bits */
1213                         if (BN_hex2bn(&start, optarg) == 0)
1214                                 fatal("Invalid start point.");
1215                         break;
1216                 case '?':
1217                 default:
1218                         usage();
1219                 }
1220         }
1221
1222         /* reinit */
1223         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1224
1225         if (optind < ac) {
1226                 printf("Too many arguments.\n");
1227                 usage();
1228         }
1229         if (change_passphrase && change_comment) {
1230                 printf("Can only have one of -p and -c.\n");
1231                 usage();
1232         }
1233         if (delete_host || hash_hosts || find_host)
1234                 do_known_hosts(pw, rr_hostname);
1235         if (print_fingerprint || print_bubblebabble)
1236                 do_fingerprint(pw);
1237         if (change_passphrase)
1238                 do_change_passphrase(pw);
1239         if (change_comment)
1240                 do_change_comment(pw);
1241         if (convert_to_ssh2)
1242                 do_convert_to_ssh2(pw);
1243         if (convert_from_ssh2)
1244                 do_convert_from_ssh2(pw);
1245         if (print_public)
1246                 do_print_public(pw);
1247         if (rr_hostname != NULL) {
1248                 unsigned int n = 0;
1249
1250                 if (have_identity) {
1251                         n = do_print_resource_record(pw,
1252                             identity_file, rr_hostname);
1253                         if (n == 0) {
1254                                 perror(identity_file);
1255                                 exit(1);
1256                         }
1257                         exit(0);
1258                 } else {
1259
1260                         n += do_print_resource_record(pw,
1261                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1262                         n += do_print_resource_record(pw,
1263                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1264
1265                         if (n == 0)
1266                                 fatal("no keys found.");
1267                         exit(0);
1268                 }
1269         }
1270         if (reader_id != NULL) {
1271 #ifdef SMARTCARD
1272                 if (download)
1273                         do_download(pw, reader_id);
1274                 else
1275                         do_upload(pw, reader_id);
1276 #else /* SMARTCARD */
1277                 fatal("no support for smartcards.");
1278 #endif /* SMARTCARD */
1279         }
1280
1281         if (do_gen_candidates) {
1282                 FILE *out = fopen(out_file, "w");
1283
1284                 if (out == NULL) {
1285                         error("Couldn't open modulus candidate file \"%s\": %s",
1286                             out_file, strerror(errno));
1287                         return (1);
1288                 }
1289                 if (bits == 0)
1290                         bits = DEFAULT_BITS;
1291                 if (gen_candidates(out, memory, bits, start) != 0)
1292                         fatal("modulus candidate generation failed");
1293
1294                 return (0);
1295         }
1296
1297         if (do_screen_candidates) {
1298                 FILE *in;
1299                 FILE *out = fopen(out_file, "w");
1300
1301                 if (have_identity && strcmp(identity_file, "-") != 0) {
1302                         if ((in = fopen(identity_file, "r")) == NULL) {
1303                                 fatal("Couldn't open modulus candidate "
1304                                     "file \"%s\": %s", identity_file,
1305                                     strerror(errno));
1306                         }
1307                 } else
1308                         in = stdin;
1309
1310                 if (out == NULL) {
1311                         fatal("Couldn't open moduli file \"%s\": %s",
1312                             out_file, strerror(errno));
1313                 }
1314                 if (prime_test(in, out, trials, generator_wanted) != 0)
1315                         fatal("modulus screening failed");
1316                 return (0);
1317         }
1318
1319         arc4random_stir();
1320
1321         if (key_type_name == NULL)
1322                 key_type_name = "rsa";
1323
1324         type = key_type_from_name(key_type_name);
1325         if (type == KEY_UNSPEC) {
1326                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1327                 exit(1);
1328         }
1329         if (bits == 0)
1330                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1331         if (type == KEY_DSA && bits != 1024)
1332                 fatal("DSA keys must be 1024 bits");
1333         if (!quiet)
1334                 printf("Generating public/private %s key pair.\n", key_type_name);
1335         private = key_generate(type, bits);
1336         if (private == NULL) {
1337                 fprintf(stderr, "key_generate failed");
1338                 exit(1);
1339         }
1340         public  = key_from_private(private);
1341
1342         if (!have_identity)
1343                 ask_filename(pw, "Enter file in which to save the key");
1344
1345         /* Create ~/.ssh directory if it doesn't already exist. */
1346         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1347         if (strstr(identity_file, dotsshdir) != NULL &&
1348             stat(dotsshdir, &st) < 0) {
1349                 if (mkdir(dotsshdir, 0700) < 0)
1350                         error("Could not create directory '%s'.", dotsshdir);
1351                 else if (!quiet)
1352                         printf("Created directory '%s'.\n", dotsshdir);
1353         }
1354         /* If the file already exists, ask the user to confirm. */
1355         if (stat(identity_file, &st) >= 0) {
1356                 char yesno[3];
1357                 printf("%s already exists.\n", identity_file);
1358                 printf("Overwrite (y/n)? ");
1359                 fflush(stdout);
1360                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1361                         exit(1);
1362                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1363                         exit(1);
1364         }
1365         /* Ask for a passphrase (twice). */
1366         if (identity_passphrase)
1367                 passphrase1 = xstrdup(identity_passphrase);
1368         else if (identity_new_passphrase)
1369                 passphrase1 = xstrdup(identity_new_passphrase);
1370         else {
1371 passphrase_again:
1372                 passphrase1 =
1373                         read_passphrase("Enter passphrase (empty for no "
1374                             "passphrase): ", RP_ALLOW_STDIN);
1375                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1376                     RP_ALLOW_STDIN);
1377                 if (strcmp(passphrase1, passphrase2) != 0) {
1378                         /*
1379                          * The passphrases do not match.  Clear them and
1380                          * retry.
1381                          */
1382                         memset(passphrase1, 0, strlen(passphrase1));
1383                         memset(passphrase2, 0, strlen(passphrase2));
1384                         xfree(passphrase1);
1385                         xfree(passphrase2);
1386                         printf("Passphrases do not match.  Try again.\n");
1387                         goto passphrase_again;
1388                 }
1389                 /* Clear the other copy of the passphrase. */
1390                 memset(passphrase2, 0, strlen(passphrase2));
1391                 xfree(passphrase2);
1392         }
1393
1394         if (identity_comment) {
1395                 strlcpy(comment, identity_comment, sizeof(comment));
1396         } else {
1397                 /* Create default commend field for the passphrase. */
1398                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1399         }
1400
1401         /* Save the key with the given passphrase and comment. */
1402         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1403                 printf("Saving the key failed: %s.\n", identity_file);
1404                 memset(passphrase1, 0, strlen(passphrase1));
1405                 xfree(passphrase1);
1406                 exit(1);
1407         }
1408         /* Clear the passphrase. */
1409         memset(passphrase1, 0, strlen(passphrase1));
1410         xfree(passphrase1);
1411
1412         /* Clear the private key and the random number generator. */
1413         key_free(private);
1414         arc4random_stir();
1415
1416         if (!quiet)
1417                 printf("Your identification has been saved in %s.\n", identity_file);
1418
1419         strlcat(identity_file, ".pub", sizeof(identity_file));
1420         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1421         if (fd == -1) {
1422                 printf("Could not save your public key in %s\n", identity_file);
1423                 exit(1);
1424         }
1425         f = fdopen(fd, "w");
1426         if (f == NULL) {
1427                 printf("fdopen %s failed", identity_file);
1428                 exit(1);
1429         }
1430         if (!key_write(public, f))
1431                 fprintf(stderr, "write key failed");
1432         fprintf(f, " %s\n", comment);
1433         fclose(f);
1434
1435         if (!quiet) {
1436                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1437                 printf("Your public key has been saved in %s.\n",
1438                     identity_file);
1439                 printf("The key fingerprint is:\n");
1440                 printf("%s %s\n", fp, comment);
1441                 xfree(fp);
1442         }
1443
1444         key_free(public);
1445         exit(0);
1446 }