crypto/openssh/ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.171 2008/07/13 21:22:52 sthen 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 #include "openbsd-compat/openssl-compat.h"
  25
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <netdb.h>
  29 #ifdef HAVE_PATHS_H
  30 # include <paths.h>
  31 #endif
  32 #include <pwd.h>
  33 #include <stdarg.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38
  39 #include "xmalloc.h"
  40 #include "key.h"
  41 #include "rsa.h"
  42 #include "authfile.h"
  43 #include "uuencode.h"
  44 #include "buffer.h"
  45 #include "pathnames.h"
  46 #include "log.h"
  47 #include "misc.h"
  48 #include "match.h"
  49 #include "hostfile.h"
  50 #include "dns.h"
  51
  52 #ifdef SMARTCARD
  53 #include "scard.h"
  54 #endif
  55
  56 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  57 #define DEFAULT_BITS            2048
  58 #define DEFAULT_BITS_DSA        1024
  59 u_int32_t bits = 0;
  60
  61 /*
  62  * Flag indicating that we just want to change the passphrase.  This can be
  63  * set on the command line.
  64  */
  65 int change_passphrase = 0;
  66
  67 /*
  68  * Flag indicating that we just want to change the comment.  This can be set
  69  * on the command line.
  70  */
  71 int change_comment = 0;
  72
  73 int quiet = 0;
  74
  75 int log_level = SYSLOG_LEVEL_INFO;
  76
  77 /* Flag indicating that we want to hash a known_hosts file */
  78 int hash_hosts = 0;
  79 /* Flag indicating that we want lookup a host in known_hosts file */
  80 int find_host = 0;
  81 /* Flag indicating that we want to delete a host from a known_hosts file */
  82 int delete_host = 0;
  83
  84 /* Flag indicating that we just want to see the key fingerprint */
  85 int print_fingerprint = 0;
  86 int print_bubblebabble = 0;
  87
  88 /* The identity file name, given on the command line or entered by the user. */
  89 char identity_file[1024];
  90 int have_identity = 0;
  91
  92 /* This is set to the passphrase if given on the command line. */
  93 char *identity_passphrase = NULL;
  94
  95 /* This is set to the new passphrase if given on the command line. */
  96 char *identity_new_passphrase = NULL;
  97
  98 /* This is set to the new comment if given on the command line. */
  99 char *identity_comment = NULL;
 100
 101 /* Dump public key file in format used by real and the original SSH 2 */
 102 int convert_to_ssh2 = 0;
 103 int convert_from_ssh2 = 0;
 104 int print_public = 0;
 105 int print_generic = 0;
 106
 107 char *key_type_name = NULL;
 108
 109 /* argv0 */
 110 extern char *__progname;
 111
 112 char hostname[MAXHOSTNAMELEN];
 113
 114 /* moduli.c */
 115 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 116 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 117
 118 static void
 119 ask_filename(struct passwd *pw, const char *prompt)
 120 {
 121         char buf[1024];
 122         char *name = NULL;
 123
 124         if (key_type_name == NULL)
 125                 name = _PATH_SSH_CLIENT_ID_RSA;
 126         else {
 127                 switch (key_type_from_name(key_type_name)) {
 128                 case KEY_RSA1:
 129                         name = _PATH_SSH_CLIENT_IDENTITY;
 130                         break;
 131                 case KEY_DSA:
 132                         name = _PATH_SSH_CLIENT_ID_DSA;
 133                         break;
 134                 case KEY_RSA:
 135                         name = _PATH_SSH_CLIENT_ID_RSA;
 136                         break;
 137                 default:
 138                         fprintf(stderr, "bad key type");
 139                         exit(1);
 140                         break;
 141                 }
 142         }
 143         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 144         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 145         if (fgets(buf, sizeof(buf), stdin) == NULL)
 146                 exit(1);
 147         buf[strcspn(buf, "\n")] = '\0';
 148         if (strcmp(buf, "") != 0)
 149                 strlcpy(identity_file, buf, sizeof(identity_file));
 150         have_identity = 1;
 151 }
 152
 153 static Key *
 154 load_identity(char *filename)
 155 {
 156         char *pass;
 157         Key *prv;
 158
 159         prv = key_load_private(filename, "", NULL);
 160         if (prv == NULL) {
 161                 if (identity_passphrase)
 162                         pass = xstrdup(identity_passphrase);
 163                 else
 164                         pass = read_passphrase("Enter passphrase: ",
 165                             RP_ALLOW_STDIN);
 166                 prv = key_load_private(filename, pass, NULL);
 167                 memset(pass, 0, strlen(pass));
 168                 xfree(pass);
 169         }
 170         return prv;
 171 }
 172
 173 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 174 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 175 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 176 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 177
 178 static void
 179 do_convert_to_ssh2(struct passwd *pw)
 180 {
 181         Key *k;
 182         u_int len;
 183         u_char *blob;
 184         struct stat st;
 185
 186         if (!have_identity)
 187                 ask_filename(pw, "Enter file in which the key is");
 188         if (stat(identity_file, &st) < 0) {
 189                 perror(identity_file);
 190                 exit(1);
 191         }
 192         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 193                 if ((k = load_identity(identity_file)) == NULL) {
 194                         fprintf(stderr, "load failed\n");
 195                         exit(1);
 196                 }
 197         }
 198         if (k->type == KEY_RSA1) {
 199                 fprintf(stderr, "version 1 keys are not supported\n");
 200                 exit(1);
 201         }
 202         if (key_to_blob(k, &blob, &len) <= 0) {
 203                 fprintf(stderr, "key_to_blob failed\n");
 204                 exit(1);
 205         }
 206         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 207         fprintf(stdout,
 208             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 209             key_size(k), key_type(k),
 210             pw->pw_name, hostname);
 211         dump_base64(stdout, blob, len);
 212         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 213         key_free(k);
 214         xfree(blob);
 215         exit(0);
 216 }
 217
 218 static void
 219 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 220 {
 221         u_int bignum_bits = buffer_get_int(b);
 222         u_int bytes = (bignum_bits + 7) / 8;
 223
 224         if (buffer_len(b) < bytes)
 225                 fatal("buffer_get_bignum_bits: input buffer too small: "
 226                     "need %d have %d", bytes, buffer_len(b));
 227         if (BN_bin2bn(buffer_ptr(b), bytes, value) == NULL)
 228                 fatal("buffer_get_bignum_bits: BN_bin2bn failed");
 229         buffer_consume(b, bytes);
 230 }
 231
 232 static Key *
 233 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 234 {
 235         Buffer b;
 236         Key *key = NULL;
 237         char *type, *cipher;
 238         u_char *sig, data[] = "abcde12345";
 239         int magic, rlen, ktype, i1, i2, i3, i4;
 240         u_int slen;
 241         u_long e;
 242
 243         buffer_init(&b);
 244         buffer_append(&b, blob, blen);
 245
 246         magic = buffer_get_int(&b);
 247         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 248                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 249                 buffer_free(&b);
 250                 return NULL;
 251         }
 252         i1 = buffer_get_int(&b);
 253         type   = buffer_get_string(&b, NULL);
 254         cipher = buffer_get_string(&b, NULL);
 255         i2 = buffer_get_int(&b);
 256         i3 = buffer_get_int(&b);
 257         i4 = buffer_get_int(&b);
 258         debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
 259         if (strcmp(cipher, "none") != 0) {
 260                 error("unsupported cipher %s", cipher);
 261                 xfree(cipher);
 262                 buffer_free(&b);
 263                 xfree(type);
 264                 return NULL;
 265         }
 266         xfree(cipher);
 267
 268         if (strstr(type, "dsa")) {
 269                 ktype = KEY_DSA;
 270         } else if (strstr(type, "rsa")) {
 271                 ktype = KEY_RSA;
 272         } else {
 273                 buffer_free(&b);
 274                 xfree(type);
 275                 return NULL;
 276         }
 277         key = key_new_private(ktype);
 278         xfree(type);
 279
 280         switch (key->type) {
 281         case KEY_DSA:
 282                 buffer_get_bignum_bits(&b, key->dsa->p);
 283                 buffer_get_bignum_bits(&b, key->dsa->g);
 284                 buffer_get_bignum_bits(&b, key->dsa->q);
 285                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 286                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 287                 break;
 288         case KEY_RSA:
 289                 e = buffer_get_char(&b);
 290                 debug("e %lx", e);
 291                 if (e < 30) {
 292                         e <<= 8;
 293                         e += buffer_get_char(&b);
 294                         debug("e %lx", e);
 295                         e <<= 8;
 296                         e += buffer_get_char(&b);
 297                         debug("e %lx", e);
 298                 }
 299                 if (!BN_set_word(key->rsa->e, e)) {
 300                         buffer_free(&b);
 301                         key_free(key);
 302                         return NULL;
 303                 }
 304                 buffer_get_bignum_bits(&b, key->rsa->d);
 305                 buffer_get_bignum_bits(&b, key->rsa->n);
 306                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 307                 buffer_get_bignum_bits(&b, key->rsa->q);
 308                 buffer_get_bignum_bits(&b, key->rsa->p);
 309                 rsa_generate_additional_parameters(key->rsa);
 310                 break;
 311         }
 312         rlen = buffer_len(&b);
 313         if (rlen != 0)
 314                 error("do_convert_private_ssh2_from_blob: "
 315                     "remaining bytes in key blob %d", rlen);
 316         buffer_free(&b);
 317
 318         /* try the key */
 319         key_sign(key, &sig, &slen, data, sizeof(data));
 320         key_verify(key, sig, slen, data, sizeof(data));
 321         xfree(sig);
 322         return key;
 323 }
 324
 325 static int
 326 get_line(FILE *fp, char *line, size_t len)
 327 {
 328         int c;
 329         size_t pos = 0;
 330
 331         line[0] = '\0';
 332         while ((c = fgetc(fp)) != EOF) {
 333                 if (pos >= len - 1) {
 334                         fprintf(stderr, "input line too long.\n");
 335                         exit(1);
 336                 }
 337                 switch (c) {
 338                 case '\r':
 339                         c = fgetc(fp);
 340                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 341                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 342                                 exit(1);
 343                         }
 344                         return pos;
 345                 case '\n':
 346                         return pos;
 347                 }
 348                 line[pos++] = c;
 349                 line[pos] = '\0';
 350         }
 351         /* We reached EOF */
 352         return -1;
 353 }
 354
 355 static void
 356 do_convert_from_ssh2(struct passwd *pw)
 357 {
 358         Key *k;
 359         int blen;
 360         u_int len;
 361         char line[1024];
 362         u_char blob[8096];
 363         char encoded[8096];
 364         struct stat st;
 365         int escaped = 0, private = 0, ok;
 366         FILE *fp;
 367
 368         if (!have_identity)
 369                 ask_filename(pw, "Enter file in which the key is");
 370         if (stat(identity_file, &st) < 0) {
 371                 perror(identity_file);
 372                 exit(1);
 373         }
 374         fp = fopen(identity_file, "r");
 375         if (fp == NULL) {
 376                 perror(identity_file);
 377                 exit(1);
 378         }
 379         encoded[0] = '\0';
 380         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 381                 if (line[blen - 1] == '\\')
 382                         escaped++;
 383                 if (strncmp(line, "----", 4) == 0 ||
 384                     strstr(line, ": ") != NULL) {
 385                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 386                                 private = 1;
 387                         if (strstr(line, " END ") != NULL) {
 388                                 break;
 389                         }
 390                         /* fprintf(stderr, "ignore: %s", line); */
 391                         continue;
 392                 }
 393                 if (escaped) {
 394                         escaped--;
 395                         /* fprintf(stderr, "escaped: %s", line); */
 396                         continue;
 397                 }
 398                 strlcat(encoded, line, sizeof(encoded));
 399         }
 400         len = strlen(encoded);
 401         if (((len % 4) == 3) &&
 402             (encoded[len-1] == '=') &&
 403             (encoded[len-2] == '=') &&
 404             (encoded[len-3] == '='))
 405                 encoded[len-3] = '\0';
 406         blen = uudecode(encoded, blob, sizeof(blob));
 407         if (blen < 0) {
 408                 fprintf(stderr, "uudecode failed.\n");
 409                 exit(1);
 410         }
 411         k = private ?
 412             do_convert_private_ssh2_from_blob(blob, blen) :
 413             key_from_blob(blob, blen);
 414         if (k == NULL) {
 415                 fprintf(stderr, "decode blob failed.\n");
 416                 exit(1);
 417         }
 418         ok = private ?
 419             (k->type == KEY_DSA ?
 420                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 421                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 422             key_write(k, stdout);
 423         if (!ok) {
 424                 fprintf(stderr, "key write failed");
 425                 exit(1);
 426         }
 427         key_free(k);
 428         if (!private)
 429                 fprintf(stdout, "\n");
 430         fclose(fp);
 431         exit(0);
 432 }
 433
 434 static void
 435 do_print_public(struct passwd *pw)
 436 {
 437         Key *prv;
 438         struct stat st;
 439
 440         if (!have_identity)
 441                 ask_filename(pw, "Enter file in which the key is");
 442         if (stat(identity_file, &st) < 0) {
 443                 perror(identity_file);
 444                 exit(1);
 445         }
 446         prv = load_identity(identity_file);
 447         if (prv == NULL) {
 448                 fprintf(stderr, "load failed\n");
 449                 exit(1);
 450         }
 451         if (!key_write(prv, stdout))
 452                 fprintf(stderr, "key_write failed");
 453         key_free(prv);
 454         fprintf(stdout, "\n");
 455         exit(0);
 456 }
 457
 458 #ifdef SMARTCARD
 459 static void
 460 do_upload(struct passwd *pw, const char *sc_reader_id)
 461 {
 462         Key *prv = NULL;
 463         struct stat st;
 464         int ret;
 465
 466         if (!have_identity)
 467                 ask_filename(pw, "Enter file in which the key is");
 468         if (stat(identity_file, &st) < 0) {
 469                 perror(identity_file);
 470                 exit(1);
 471         }
 472         prv = load_identity(identity_file);
 473         if (prv == NULL) {
 474                 error("load failed");
 475                 exit(1);
 476         }
 477         ret = sc_put_key(prv, sc_reader_id);
 478         key_free(prv);
 479         if (ret < 0)
 480                 exit(1);
 481         logit("loading key done");
 482         exit(0);
 483 }
 484
 485 static void
 486 do_download(struct passwd *pw, const char *sc_reader_id)
 487 {
 488         Key **keys = NULL;
 489         int i;
 490
 491         keys = sc_get_keys(sc_reader_id, NULL);
 492         if (keys == NULL)
 493                 fatal("cannot read public key from smartcard");
 494         for (i = 0; keys[i]; i++) {
 495                 key_write(keys[i], stdout);
 496                 key_free(keys[i]);
 497                 fprintf(stdout, "\n");
 498         }
 499         xfree(keys);
 500         exit(0);
 501 }
 502 #endif /* SMARTCARD */
 503
 504 static void
 505 do_fingerprint(struct passwd *pw)
 506 {
 507         FILE *f;
 508         Key *public;
 509         char *comment = NULL, *cp, *ep, line[16*1024], *fp, *ra;
 510         int i, skip = 0, num = 0, invalid = 1;
 511         enum fp_rep rep;
 512         enum fp_type fptype;
 513         struct stat st;
 514
 515         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 516         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 517
 518         if (!have_identity)
 519                 ask_filename(pw, "Enter file in which the key is");
 520         if (stat(identity_file, &st) < 0) {
 521                 perror(identity_file);
 522                 exit(1);
 523         }
 524         public = key_load_public(identity_file, &comment);
 525         if (public != NULL) {
 526                 fp = key_fingerprint(public, fptype, rep);
 527                 ra = key_fingerprint(public, fptype, SSH_FP_RANDOMART);
 528                 printf("%u %s %s (%s)\n", key_size(public), fp, comment,
 529                     key_type(public));
 530                 if (log_level >= SYSLOG_LEVEL_VERBOSE)
 531                         printf("%s\n", ra);
 532                 key_free(public);
 533                 xfree(comment);
 534                 xfree(ra);
 535                 xfree(fp);
 536                 exit(0);
 537         }
 538         if (comment) {
 539                 xfree(comment);
 540                 comment = NULL;
 541         }
 542
 543         f = fopen(identity_file, "r");
 544         if (f != NULL) {
 545                 while (fgets(line, sizeof(line), f)) {
 546                         if ((cp = strchr(line, '\n')) == NULL) {
 547                                 error("line %d too long: %.40s...",
 548                                     num + 1, line);
 549                                 skip = 1;
 550                                 continue;
 551                         }
 552                         num++;
 553                         if (skip) {
 554                                 skip = 0;
 555                                 continue;
 556                         }
 557                         *cp = '\0';
 558
 559                         /* Skip leading whitespace, empty and comment lines. */
 560                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 561                                 ;
 562                         if (!*cp || *cp == '\n' || *cp == '#')
 563                                 continue;
 564                         i = strtol(cp, &ep, 10);
 565                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 566                                 int quoted = 0;
 567                                 comment = cp;
 568                                 for (; *cp && (quoted || (*cp != ' ' &&
 569                                     *cp != '\t')); cp++) {
 570                                         if (*cp == '\\' && cp[1] == '"')
 571                                                 cp++;   /* Skip both */
 572                                         else if (*cp == '"')
 573                                                 quoted = !quoted;
 574                                 }
 575                                 if (!*cp)
 576                                         continue;
 577                                 *cp++ = '\0';
 578                         }
 579                         ep = cp;
 580                         public = key_new(KEY_RSA1);
 581                         if (key_read(public, &cp) != 1) {
 582                                 cp = ep;
 583                                 key_free(public);
 584                                 public = key_new(KEY_UNSPEC);
 585                                 if (key_read(public, &cp) != 1) {
 586                                         key_free(public);
 587                                         continue;
 588                                 }
 589                         }
 590                         comment = *cp ? cp : comment;
 591                         fp = key_fingerprint(public, fptype, rep);
 592                         ra = key_fingerprint(public, fptype, SSH_FP_RANDOMART);
 593                         printf("%u %s %s (%s)\n", key_size(public), fp,
 594                             comment ? comment : "no comment", key_type(public));
 595                         if (log_level >= SYSLOG_LEVEL_VERBOSE)
 596                                 printf("%s\n", ra);
 597                         xfree(ra);
 598                         xfree(fp);
 599                         key_free(public);
 600                         invalid = 0;
 601                 }
 602                 fclose(f);
 603         }
 604         if (invalid) {
 605                 printf("%s is not a public key file.\n", identity_file);
 606                 exit(1);
 607         }
 608         exit(0);
 609 }
 610
 611 static void
 612 print_host(FILE *f, const char *name, Key *public, int hash)
 613 {
 614         if (print_fingerprint) {
 615                 enum fp_rep rep;
 616                 enum fp_type fptype;
 617                 char *fp, *ra;
 618
 619                 fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 620                 rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 621                 fp = key_fingerprint(public, fptype, rep);
 622                 ra = key_fingerprint(public, fptype, SSH_FP_RANDOMART);
 623                 printf("%u %s %s (%s)\n", key_size(public), fp, name,
 624                     key_type(public));
 625                 if (log_level >= SYSLOG_LEVEL_VERBOSE)
 626                         printf("%s\n", ra);
 627                 xfree(ra);
 628                 xfree(fp);
 629         } else {
 630                 if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 631                         fatal("hash_host failed");
 632                 fprintf(f, "%s ", name);
 633                 if (!key_write(public, f))
 634                         fatal("key_write failed");
 635                 fprintf(f, "\n");
 636         }
 637 }
 638
 639 static void
 640 do_known_hosts(struct passwd *pw, const char *name)
 641 {
 642         FILE *in, *out = stdout;
 643         Key *public;
 644         char *cp, *cp2, *kp, *kp2;
 645         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 646         int c, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 647
 648         if (!have_identity) {
 649                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 650                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 651                     sizeof(identity_file))
 652                         fatal("Specified known hosts path too long");
 653                 xfree(cp);
 654                 have_identity = 1;
 655         }
 656         if ((in = fopen(identity_file, "r")) == NULL)
 657                 fatal("fopen: %s", strerror(errno));
 658
 659         /*
 660          * Find hosts goes to stdout, hash and deletions happen in-place
 661          * A corner case is ssh-keygen -HF foo, which should go to stdout
 662          */
 663         if (!find_host && (hash_hosts || delete_host)) {
 664                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 665                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 666                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 667                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 668                         fatal("known_hosts path too long");
 669                 umask(077);
 670                 if ((c = mkstemp(tmp)) == -1)
 671                         fatal("mkstemp: %s", strerror(errno));
 672                 if ((out = fdopen(c, "w")) == NULL) {
 673                         c = errno;
 674                         unlink(tmp);
 675                         fatal("fdopen: %s", strerror(c));
 676                 }
 677                 inplace = 1;
 678         }
 679
 680         while (fgets(line, sizeof(line), in)) {
 681                 if ((cp = strchr(line, '\n')) == NULL) {
 682                         error("line %d too long: %.40s...", num + 1, line);
 683                         skip = 1;
 684                         invalid = 1;
 685                         continue;
 686                 }
 687                 num++;
 688                 if (skip) {
 689                         skip = 0;
 690                         continue;
 691                 }
 692                 *cp = '\0';
 693
 694                 /* Skip leading whitespace, empty and comment lines. */
 695                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 696                         ;
 697                 if (!*cp || *cp == '\n' || *cp == '#') {
 698                         if (inplace)
 699                                 fprintf(out, "%s\n", cp);
 700                         continue;
 701                 }
 702                 /* Find the end of the host name portion. */
 703                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 704                         ;
 705                 if (*kp == '\0' || *(kp + 1) == '\0') {
 706                         error("line %d missing key: %.40s...",
 707                             num, line);
 708                         invalid = 1;
 709                         continue;
 710                 }
 711                 *kp++ = '\0';
 712                 kp2 = kp;
 713
 714                 public = key_new(KEY_RSA1);
 715                 if (key_read(public, &kp) != 1) {
 716                         kp = kp2;
 717                         key_free(public);
 718                         public = key_new(KEY_UNSPEC);
 719                         if (key_read(public, &kp) != 1) {
 720                                 error("line %d invalid key: %.40s...",
 721                                     num, line);
 722                                 key_free(public);
 723                                 invalid = 1;
 724                                 continue;
 725                         }
 726                 }
 727
 728                 if (*cp == HASH_DELIM) {
 729                         if (find_host || delete_host) {
 730                                 cp2 = host_hash(name, cp, strlen(cp));
 731                                 if (cp2 == NULL) {
 732                                         error("line %d: invalid hashed "
 733                                             "name: %.64s...", num, line);
 734                                         invalid = 1;
 735                                         continue;
 736                                 }
 737                                 c = (strcmp(cp2, cp) == 0);
 738                                 if (find_host && c) {
 739                                         printf("# Host %s found: "
 740                                             "line %d type %s\n", name,
 741                                             num, key_type(public));
 742                                         print_host(out, cp, public, 0);
 743                                 }
 744                                 if (delete_host && !c)
 745                                         print_host(out, cp, public, 0);
 746                         } else if (hash_hosts)
 747                                 print_host(out, cp, public, 0);
 748                 } else {
 749                         if (find_host || delete_host) {
 750                                 c = (match_hostname(name, cp,
 751                                     strlen(cp)) == 1);
 752                                 if (find_host && c) {
 753                                         printf("# Host %s found: "
 754                                             "line %d type %s\n", name,
 755                                             num, key_type(public));
 756                                         print_host(out, name, public,
 757                                             hash_hosts);
 758                                 }
 759                                 if (delete_host && !c)
 760                                         print_host(out, cp, public, 0);
 761                         } else if (hash_hosts) {
 762                                 for (cp2 = strsep(&cp, ",");
 763                                     cp2 != NULL && *cp2 != '\0';
 764                                     cp2 = strsep(&cp, ",")) {
 765                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 766                                                 fprintf(stderr, "Warning: "
 767                                                     "ignoring host name with "
 768                                                     "metacharacters: %.64s\n",
 769                                                     cp2);
 770                                         else
 771                                                 print_host(out, cp2, public, 1);
 772                                 }
 773                                 has_unhashed = 1;
 774                         }
 775                 }
 776                 key_free(public);
 777         }
 778         fclose(in);
 779
 780         if (invalid) {
 781                 fprintf(stderr, "%s is not a valid known_hosts file.\n",
 782                     identity_file);
 783                 if (inplace) {
 784                         fprintf(stderr, "Not replacing existing known_hosts "
 785                             "file because of errors\n");
 786                         fclose(out);
 787                         unlink(tmp);
 788                 }
 789                 exit(1);
 790         }
 791
 792         if (inplace) {
 793                 fclose(out);
 794
 795                 /* Backup existing file */
 796                 if (unlink(old) == -1 && errno != ENOENT)
 797                         fatal("unlink %.100s: %s", old, strerror(errno));
 798                 if (link(identity_file, old) == -1)
 799                         fatal("link %.100s to %.100s: %s", identity_file, old,
 800                             strerror(errno));
 801                 /* Move new one into place */
 802                 if (rename(tmp, identity_file) == -1) {
 803                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 804                             strerror(errno));
 805                         unlink(tmp);
 806                         unlink(old);
 807                         exit(1);
 808                 }
 809
 810                 fprintf(stderr, "%s updated.\n", identity_file);
 811                 fprintf(stderr, "Original contents retained as %s\n", old);
 812                 if (has_unhashed) {
 813                         fprintf(stderr, "WARNING: %s contains unhashed "
 814                             "entries\n", old);
 815                         fprintf(stderr, "Delete this file to ensure privacy "
 816                             "of hostnames\n");
 817                 }
 818         }
 819
 820         exit(0);
 821 }
 822
 823 /*
 824  * Perform changing a passphrase.  The argument is the passwd structure
 825  * for the current user.
 826  */
 827 static void
 828 do_change_passphrase(struct passwd *pw)
 829 {
 830         char *comment;
 831         char *old_passphrase, *passphrase1, *passphrase2;
 832         struct stat st;
 833         Key *private;
 834
 835         if (!have_identity)
 836                 ask_filename(pw, "Enter file in which the key is");
 837         if (stat(identity_file, &st) < 0) {
 838                 perror(identity_file);
 839                 exit(1);
 840         }
 841         /* Try to load the file with empty passphrase. */
 842         private = key_load_private(identity_file, "", &comment);
 843         if (private == NULL) {
 844                 if (identity_passphrase)
 845                         old_passphrase = xstrdup(identity_passphrase);
 846                 else
 847                         old_passphrase =
 848                             read_passphrase("Enter old passphrase: ",
 849                             RP_ALLOW_STDIN);
 850                 private = key_load_private(identity_file, old_passphrase,
 851                     &comment);
 852                 memset(old_passphrase, 0, strlen(old_passphrase));
 853                 xfree(old_passphrase);
 854                 if (private == NULL) {
 855                         printf("Bad passphrase.\n");
 856                         exit(1);
 857                 }
 858         }
 859         printf("Key has comment '%s'\n", comment);
 860
 861         /* Ask the new passphrase (twice). */
 862         if (identity_new_passphrase) {
 863                 passphrase1 = xstrdup(identity_new_passphrase);
 864                 passphrase2 = NULL;
 865         } else {
 866                 passphrase1 =
 867                         read_passphrase("Enter new passphrase (empty for no "
 868                             "passphrase): ", RP_ALLOW_STDIN);
 869                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 870                     RP_ALLOW_STDIN);
 871
 872                 /* Verify that they are the same. */
 873                 if (strcmp(passphrase1, passphrase2) != 0) {
 874                         memset(passphrase1, 0, strlen(passphrase1));
 875                         memset(passphrase2, 0, strlen(passphrase2));
 876                         xfree(passphrase1);
 877                         xfree(passphrase2);
 878                         printf("Pass phrases do not match.  Try again.\n");
 879                         exit(1);
 880                 }
 881                 /* Destroy the other copy. */
 882                 memset(passphrase2, 0, strlen(passphrase2));
 883                 xfree(passphrase2);
 884         }
 885
 886         /* Save the file using the new passphrase. */
 887         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 888                 printf("Saving the key failed: %s.\n", identity_file);
 889                 memset(passphrase1, 0, strlen(passphrase1));
 890                 xfree(passphrase1);
 891                 key_free(private);
 892                 xfree(comment);
 893                 exit(1);
 894         }
 895         /* Destroy the passphrase and the copy of the key in memory. */
 896         memset(passphrase1, 0, strlen(passphrase1));
 897         xfree(passphrase1);
 898         key_free(private);               /* Destroys contents */
 899         xfree(comment);
 900
 901         printf("Your identification has been saved with the new passphrase.\n");
 902         exit(0);
 903 }
 904
 905 /*
 906  * Print the SSHFP RR.
 907  */
 908 static int
 909 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 910 {
 911         Key *public;
 912         char *comment = NULL;
 913         struct stat st;
 914
 915         if (fname == NULL)
 916                 ask_filename(pw, "Enter file in which the key is");
 917         if (stat(fname, &st) < 0) {
 918                 if (errno == ENOENT)
 919                         return 0;
 920                 perror(fname);
 921                 exit(1);
 922         }
 923         public = key_load_public(fname, &comment);
 924         if (public != NULL) {
 925                 export_dns_rr(hname, public, stdout, print_generic);
 926                 key_free(public);
 927                 xfree(comment);
 928                 return 1;
 929         }
 930         if (comment)
 931                 xfree(comment);
 932
 933         printf("failed to read v2 public key from %s.\n", fname);
 934         exit(1);
 935 }
 936
 937 /*
 938  * Change the comment of a private key file.
 939  */
 940 static void
 941 do_change_comment(struct passwd *pw)
 942 {
 943         char new_comment[1024], *comment, *passphrase;
 944         Key *private;
 945         Key *public;
 946         struct stat st;
 947         FILE *f;
 948         int fd;
 949
 950         if (!have_identity)
 951                 ask_filename(pw, "Enter file in which the key is");
 952         if (stat(identity_file, &st) < 0) {
 953                 perror(identity_file);
 954                 exit(1);
 955         }
 956         private = key_load_private(identity_file, "", &comment);
 957         if (private == NULL) {
 958                 if (identity_passphrase)
 959                         passphrase = xstrdup(identity_passphrase);
 960                 else if (identity_new_passphrase)
 961                         passphrase = xstrdup(identity_new_passphrase);
 962                 else
 963                         passphrase = read_passphrase("Enter passphrase: ",
 964                             RP_ALLOW_STDIN);
 965                 /* Try to load using the passphrase. */
 966                 private = key_load_private(identity_file, passphrase, &comment);
 967                 if (private == NULL) {
 968                         memset(passphrase, 0, strlen(passphrase));
 969                         xfree(passphrase);
 970                         printf("Bad passphrase.\n");
 971                         exit(1);
 972                 }
 973         } else {
 974                 passphrase = xstrdup("");
 975         }
 976         if (private->type != KEY_RSA1) {
 977                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 978                 key_free(private);
 979                 exit(1);
 980         }
 981         printf("Key now has comment '%s'\n", comment);
 982
 983         if (identity_comment) {
 984                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 985         } else {
 986                 printf("Enter new comment: ");
 987                 fflush(stdout);
 988                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 989                         memset(passphrase, 0, strlen(passphrase));
 990                         key_free(private);
 991                         exit(1);
 992                 }
 993                 new_comment[strcspn(new_comment, "\n")] = '\0';
 994         }
 995
 996         /* Save the file using the new passphrase. */
 997         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 998                 printf("Saving the key failed: %s.\n", identity_file);
 999                 memset(passphrase, 0, strlen(passphrase));
1000                 xfree(passphrase);
1001                 key_free(private);
1002                 xfree(comment);
1003                 exit(1);
1004         }
1005         memset(passphrase, 0, strlen(passphrase));
1006         xfree(passphrase);
1007         public = key_from_private(private);
1008         key_free(private);
1009
1010         strlcat(identity_file, ".pub", sizeof(identity_file));
1011         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1012         if (fd == -1) {
1013                 printf("Could not save your public key in %s\n", identity_file);
1014                 exit(1);
1015         }
1016         f = fdopen(fd, "w");
1017         if (f == NULL) {
1018                 printf("fdopen %s failed", identity_file);
1019                 exit(1);
1020         }
1021         if (!key_write(public, f))
1022                 fprintf(stderr, "write key failed");
1023         key_free(public);
1024         fprintf(f, " %s\n", new_comment);
1025         fclose(f);
1026
1027         xfree(comment);
1028
1029         printf("The comment in your key file has been changed.\n");
1030         exit(0);
1031 }
1032
1033 static void
1034 usage(void)
1035 {
1036         fprintf(stderr, "usage: %s [options]\n", __progname);
1037         fprintf(stderr, "Options:\n");
1038         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1039         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1040         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1041         fprintf(stderr, "  -C comment  Provide new comment.\n");
1042         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1043 #ifdef SMARTCARD
1044         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1045 #endif /* SMARTCARD */
1046         fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
1047         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1048         fprintf(stderr, "  -f filename Filename of the key file.\n");
1049         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1050         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1051         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1052         fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
1053         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1054         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1055         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1056         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1057         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1058         fprintf(stderr, "  -q          Quiet.\n");
1059         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1060         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1061         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1062         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1063         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1064 #ifdef SMARTCARD
1065         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1066 #endif /* SMARTCARD */
1067         fprintf(stderr, "  -v          Verbose.\n");
1068         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1069         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1070
1071         exit(1);
1072 }
1073
1074 /*
1075  * Main program for key management.
1076  */
1077 int
1078 main(int argc, char **argv)
1079 {
1080         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1081         char out_file[MAXPATHLEN], *reader_id = NULL;
1082         char *rr_hostname = NULL;
1083         Key *private, *public;
1084         struct passwd *pw;
1085         struct stat st;
1086         int opt, type, fd, download = 0;
1087         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1088         int do_gen_candidates = 0, do_screen_candidates = 0;
1089         BIGNUM *start = NULL;
1090         FILE *f;
1091         const char *errstr;
1092
1093         extern int optind;
1094         extern char *optarg;
1095
1096         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1097         sanitise_stdfd();
1098
1099         __progname = ssh_get_progname(argv[0]);
1100
1101         SSLeay_add_all_algorithms();
1102         log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1103
1104         init_rng();
1105         seed_rng();
1106
1107         /* we need this for the home * directory.  */
1108         pw = getpwuid(getuid());
1109         if (!pw) {
1110                 printf("You don't exist, go away!\n");
1111                 exit(1);
1112         }
1113         if (gethostname(hostname, sizeof(hostname)) < 0) {
1114                 perror("gethostname");
1115                 exit(1);
1116         }
1117
1118         while ((opt = getopt(argc, argv,
1119             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1120                 switch (opt) {
1121                 case 'b':
1122                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1123                         if (errstr)
1124                                 fatal("Bits has bad value %s (%s)",
1125                                         optarg, errstr);
1126                         break;
1127                 case 'F':
1128                         find_host = 1;
1129                         rr_hostname = optarg;
1130                         break;
1131                 case 'H':
1132                         hash_hosts = 1;
1133                         break;
1134                 case 'R':
1135                         delete_host = 1;
1136                         rr_hostname = optarg;
1137                         break;
1138                 case 'l':
1139                         print_fingerprint = 1;
1140                         break;
1141                 case 'B':
1142                         print_bubblebabble = 1;
1143                         break;
1144                 case 'p':
1145                         change_passphrase = 1;
1146                         break;
1147                 case 'c':
1148                         change_comment = 1;
1149                         break;
1150                 case 'f':
1151                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1152                             sizeof(identity_file))
1153                                 fatal("Identity filename too long");
1154                         have_identity = 1;
1155                         break;
1156                 case 'g':
1157                         print_generic = 1;
1158                         break;
1159                 case 'P':
1160                         identity_passphrase = optarg;
1161                         break;
1162                 case 'N':
1163                         identity_new_passphrase = optarg;
1164                         break;
1165                 case 'C':
1166                         identity_comment = optarg;
1167                         break;
1168                 case 'q':
1169                         quiet = 1;
1170                         break;
1171                 case 'e':
1172                 case 'x':
1173                         /* export key */
1174                         convert_to_ssh2 = 1;
1175                         break;
1176                 case 'i':
1177                 case 'X':
1178                         /* import key */
1179                         convert_from_ssh2 = 1;
1180                         break;
1181                 case 'y':
1182                         print_public = 1;
1183                         break;
1184                 case 'd':
1185                         key_type_name = "dsa";
1186                         break;
1187                 case 't':
1188                         key_type_name = optarg;
1189                         break;
1190                 case 'D':
1191                         download = 1;
1192                         /*FALLTHROUGH*/
1193                 case 'U':
1194                         reader_id = optarg;
1195                         break;
1196                 case 'v':
1197                         if (log_level == SYSLOG_LEVEL_INFO)
1198                                 log_level = SYSLOG_LEVEL_DEBUG1;
1199                         else {
1200                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1201                                     log_level < SYSLOG_LEVEL_DEBUG3)
1202                                         log_level++;
1203                         }
1204                         break;
1205                 case 'r':
1206                         rr_hostname = optarg;
1207                         break;
1208                 case 'W':
1209                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1210                             UINT_MAX, &errstr);
1211                         if (errstr)
1212                                 fatal("Desired generator has bad value: %s (%s)",
1213                                         optarg, errstr);
1214                         break;
1215                 case 'a':
1216                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1217                         if (errstr)
1218                                 fatal("Invalid number of trials: %s (%s)",
1219                                         optarg, errstr);
1220                         break;
1221                 case 'M':
1222                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1223                         if (errstr) {
1224                                 fatal("Memory limit is %s: %s", errstr, optarg);
1225                         }
1226                         break;
1227                 case 'G':
1228                         do_gen_candidates = 1;
1229                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1230                             sizeof(out_file))
1231                                 fatal("Output filename too long");
1232                         break;
1233                 case 'T':
1234                         do_screen_candidates = 1;
1235                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1236                             sizeof(out_file))
1237                                 fatal("Output filename too long");
1238                         break;
1239                 case 'S':
1240                         /* XXX - also compare length against bits */
1241                         if (BN_hex2bn(&start, optarg) == 0)
1242                                 fatal("Invalid start point.");
1243                         break;
1244                 case '?':
1245                 default:
1246                         usage();
1247                 }
1248         }
1249
1250         /* reinit */
1251         log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
1252
1253         if (optind < argc) {
1254                 printf("Too many arguments.\n");
1255                 usage();
1256         }
1257         if (change_passphrase && change_comment) {
1258                 printf("Can only have one of -p and -c.\n");
1259                 usage();
1260         }
1261         if (print_fingerprint && (delete_host || hash_hosts)) {
1262                 printf("Cannot use -l with -D or -R.\n");
1263                 usage();
1264         }
1265         if (delete_host || hash_hosts || find_host)
1266                 do_known_hosts(pw, rr_hostname);
1267         if (print_fingerprint || print_bubblebabble)
1268                 do_fingerprint(pw);
1269         if (change_passphrase)
1270                 do_change_passphrase(pw);
1271         if (change_comment)
1272                 do_change_comment(pw);
1273         if (convert_to_ssh2)
1274                 do_convert_to_ssh2(pw);
1275         if (convert_from_ssh2)
1276                 do_convert_from_ssh2(pw);
1277         if (print_public)
1278                 do_print_public(pw);
1279         if (rr_hostname != NULL) {
1280                 unsigned int n = 0;
1281
1282                 if (have_identity) {
1283                         n = do_print_resource_record(pw,
1284                             identity_file, rr_hostname);
1285                         if (n == 0) {
1286                                 perror(identity_file);
1287                                 exit(1);
1288                         }
1289                         exit(0);
1290                 } else {
1291
1292                         n += do_print_resource_record(pw,
1293                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1294                         n += do_print_resource_record(pw,
1295                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1296
1297                         if (n == 0)
1298                                 fatal("no keys found.");
1299                         exit(0);
1300                 }
1301         }
1302         if (reader_id != NULL) {
1303 #ifdef SMARTCARD
1304                 if (download)
1305                         do_download(pw, reader_id);
1306                 else
1307                         do_upload(pw, reader_id);
1308 #else /* SMARTCARD */
1309                 fatal("no support for smartcards.");
1310 #endif /* SMARTCARD */
1311         }
1312
1313         if (do_gen_candidates) {
1314                 FILE *out = fopen(out_file, "w");
1315
1316                 if (out == NULL) {
1317                         error("Couldn't open modulus candidate file \"%s\": %s",
1318                             out_file, strerror(errno));
1319                         return (1);
1320                 }
1321                 if (bits == 0)
1322                         bits = DEFAULT_BITS;
1323                 if (gen_candidates(out, memory, bits, start) != 0)
1324                         fatal("modulus candidate generation failed");
1325
1326                 return (0);
1327         }
1328
1329         if (do_screen_candidates) {
1330                 FILE *in;
1331                 FILE *out = fopen(out_file, "w");
1332
1333                 if (have_identity && strcmp(identity_file, "-") != 0) {
1334                         if ((in = fopen(identity_file, "r")) == NULL) {
1335                                 fatal("Couldn't open modulus candidate "
1336                                     "file \"%s\": %s", identity_file,
1337                                     strerror(errno));
1338                         }
1339                 } else
1340                         in = stdin;
1341
1342                 if (out == NULL) {
1343                         fatal("Couldn't open moduli file \"%s\": %s",
1344                             out_file, strerror(errno));
1345                 }
1346                 if (prime_test(in, out, trials, generator_wanted) != 0)
1347                         fatal("modulus screening failed");
1348                 return (0);
1349         }
1350
1351         arc4random_stir();
1352
1353         if (key_type_name == NULL)
1354                 key_type_name = "rsa";
1355
1356         type = key_type_from_name(key_type_name);
1357         if (type == KEY_UNSPEC) {
1358                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1359                 exit(1);
1360         }
1361         if (bits == 0)
1362                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1363         if (type == KEY_DSA && bits != 1024)
1364                 fatal("DSA keys must be 1024 bits");
1365         if (!quiet)
1366                 printf("Generating public/private %s key pair.\n", key_type_name);
1367         private = key_generate(type, bits);
1368         if (private == NULL) {
1369                 fprintf(stderr, "key_generate failed");
1370                 exit(1);
1371         }
1372         public  = key_from_private(private);
1373
1374         if (!have_identity)
1375                 ask_filename(pw, "Enter file in which to save the key");
1376
1377         /* Create ~/.ssh directory if it doesn't already exist. */
1378         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1379         if (strstr(identity_file, dotsshdir) != NULL &&
1380             stat(dotsshdir, &st) < 0) {
1381                 if (mkdir(dotsshdir, 0700) < 0)
1382                         error("Could not create directory '%s'.", dotsshdir);
1383                 else if (!quiet)
1384                         printf("Created directory '%s'.\n", dotsshdir);
1385         }
1386         /* If the file already exists, ask the user to confirm. */
1387         if (stat(identity_file, &st) >= 0) {
1388                 char yesno[3];
1389                 printf("%s already exists.\n", identity_file);
1390                 printf("Overwrite (y/n)? ");
1391                 fflush(stdout);
1392                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1393                         exit(1);
1394                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1395                         exit(1);
1396         }
1397         /* Ask for a passphrase (twice). */
1398         if (identity_passphrase)
1399                 passphrase1 = xstrdup(identity_passphrase);
1400         else if (identity_new_passphrase)
1401                 passphrase1 = xstrdup(identity_new_passphrase);
1402         else {
1403 passphrase_again:
1404                 passphrase1 =
1405                         read_passphrase("Enter passphrase (empty for no "
1406                             "passphrase): ", RP_ALLOW_STDIN);
1407                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1408                     RP_ALLOW_STDIN);
1409                 if (strcmp(passphrase1, passphrase2) != 0) {
1410                         /*
1411                          * The passphrases do not match.  Clear them and
1412                          * retry.
1413                          */
1414                         memset(passphrase1, 0, strlen(passphrase1));
1415                         memset(passphrase2, 0, strlen(passphrase2));
1416                         xfree(passphrase1);
1417                         xfree(passphrase2);
1418                         printf("Passphrases do not match.  Try again.\n");
1419                         goto passphrase_again;
1420                 }
1421                 /* Clear the other copy of the passphrase. */
1422                 memset(passphrase2, 0, strlen(passphrase2));
1423                 xfree(passphrase2);
1424         }
1425
1426         if (identity_comment) {
1427                 strlcpy(comment, identity_comment, sizeof(comment));
1428         } else {
1429                 /* Create default commend field for the passphrase. */
1430                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1431         }
1432
1433         /* Save the key with the given passphrase and comment. */
1434         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1435                 printf("Saving the key failed: %s.\n", identity_file);
1436                 memset(passphrase1, 0, strlen(passphrase1));
1437                 xfree(passphrase1);
1438                 exit(1);
1439         }
1440         /* Clear the passphrase. */
1441         memset(passphrase1, 0, strlen(passphrase1));
1442         xfree(passphrase1);
1443
1444         /* Clear the private key and the random number generator. */
1445         key_free(private);
1446         arc4random_stir();
1447
1448         if (!quiet)
1449                 printf("Your identification has been saved in %s.\n", identity_file);
1450
1451         strlcat(identity_file, ".pub", sizeof(identity_file));
1452         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1453         if (fd == -1) {
1454                 printf("Could not save your public key in %s\n", identity_file);
1455                 exit(1);
1456         }
1457         f = fdopen(fd, "w");
1458         if (f == NULL) {
1459                 printf("fdopen %s failed", identity_file);
1460                 exit(1);
1461         }
1462         if (!key_write(public, f))
1463                 fprintf(stderr, "write key failed");
1464         fprintf(f, " %s\n", comment);
1465         fclose(f);
1466
1467         if (!quiet) {
1468                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1469                 char *ra = key_fingerprint(public, SSH_FP_MD5,
1470                     SSH_FP_RANDOMART);
1471                 printf("Your public key has been saved in %s.\n",
1472                     identity_file);
1473                 printf("The key fingerprint is:\n");
1474                 printf("%s %s\n", fp, comment);
1475                 printf("The key's randomart image is:\n");
1476                 printf("%s\n", ra);
1477                 xfree(ra);
1478                 xfree(fp);
1479         }
1480
1481         key_free(public);
1482         exit(0);
1483 }