ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.170 2008/06/12 21:14:46 grunk 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%s\n", key_size(public), fp, name,
 624                     key_type(public), ra);
 625                 xfree(ra);
 626                 xfree(fp);
 627         } else {
 628                 if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 629                         fatal("hash_host failed");
 630                 fprintf(f, "%s ", name);
 631                 if (!key_write(public, f))
 632                         fatal("key_write failed");
 633                 fprintf(f, "\n");
 634         }
 635 }
 636
 637 static void
 638 do_known_hosts(struct passwd *pw, const char *name)
 639 {
 640         FILE *in, *out = stdout;
 641         Key *public;
 642         char *cp, *cp2, *kp, *kp2;
 643         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 644         int c, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 645
 646         if (!have_identity) {
 647                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 648                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 649                     sizeof(identity_file))
 650                         fatal("Specified known hosts path too long");
 651                 xfree(cp);
 652                 have_identity = 1;
 653         }
 654         if ((in = fopen(identity_file, "r")) == NULL)
 655                 fatal("fopen: %s", strerror(errno));
 656
 657         /*
 658          * Find hosts goes to stdout, hash and deletions happen in-place
 659          * A corner case is ssh-keygen -HF foo, which should go to stdout
 660          */
 661         if (!find_host && (hash_hosts || delete_host)) {
 662                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 663                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 664                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 665                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 666                         fatal("known_hosts path too long");
 667                 umask(077);
 668                 if ((c = mkstemp(tmp)) == -1)
 669                         fatal("mkstemp: %s", strerror(errno));
 670                 if ((out = fdopen(c, "w")) == NULL) {
 671                         c = errno;
 672                         unlink(tmp);
 673                         fatal("fdopen: %s", strerror(c));
 674                 }
 675                 inplace = 1;
 676         }
 677
 678         while (fgets(line, sizeof(line), in)) {
 679                 if ((cp = strchr(line, '\n')) == NULL) {
 680                         error("line %d too long: %.40s...", num + 1, line);
 681                         skip = 1;
 682                         invalid = 1;
 683                         continue;
 684                 }
 685                 num++;
 686                 if (skip) {
 687                         skip = 0;
 688                         continue;
 689                 }
 690                 *cp = '\0';
 691
 692                 /* Skip leading whitespace, empty and comment lines. */
 693                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 694                         ;
 695                 if (!*cp || *cp == '\n' || *cp == '#') {
 696                         if (inplace)
 697                                 fprintf(out, "%s\n", cp);
 698                         continue;
 699                 }
 700                 /* Find the end of the host name portion. */
 701                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 702                         ;
 703                 if (*kp == '\0' || *(kp + 1) == '\0') {
 704                         error("line %d missing key: %.40s...",
 705                             num, line);
 706                         invalid = 1;
 707                         continue;
 708                 }
 709                 *kp++ = '\0';
 710                 kp2 = kp;
 711
 712                 public = key_new(KEY_RSA1);
 713                 if (key_read(public, &kp) != 1) {
 714                         kp = kp2;
 715                         key_free(public);
 716                         public = key_new(KEY_UNSPEC);
 717                         if (key_read(public, &kp) != 1) {
 718                                 error("line %d invalid key: %.40s...",
 719                                     num, line);
 720                                 key_free(public);
 721                                 invalid = 1;
 722                                 continue;
 723                         }
 724                 }
 725
 726                 if (*cp == HASH_DELIM) {
 727                         if (find_host || delete_host) {
 728                                 cp2 = host_hash(name, cp, strlen(cp));
 729                                 if (cp2 == NULL) {
 730                                         error("line %d: invalid hashed "
 731                                             "name: %.64s...", num, line);
 732                                         invalid = 1;
 733                                         continue;
 734                                 }
 735                                 c = (strcmp(cp2, cp) == 0);
 736                                 if (find_host && c) {
 737                                         printf("# Host %s found: "
 738                                             "line %d type %s\n", name,
 739                                             num, key_type(public));
 740                                         print_host(out, cp, public, 0);
 741                                 }
 742                                 if (delete_host && !c)
 743                                         print_host(out, cp, public, 0);
 744                         } else if (hash_hosts)
 745                                 print_host(out, cp, public, 0);
 746                 } else {
 747                         if (find_host || delete_host) {
 748                                 c = (match_hostname(name, cp,
 749                                     strlen(cp)) == 1);
 750                                 if (find_host && c) {
 751                                         printf("# Host %s found: "
 752                                             "line %d type %s\n", name,
 753                                             num, key_type(public));
 754                                         print_host(out, name, public,
 755                                             hash_hosts);
 756                                 }
 757                                 if (delete_host && !c)
 758                                         print_host(out, cp, public, 0);
 759                         } else if (hash_hosts) {
 760                                 for (cp2 = strsep(&cp, ",");
 761                                     cp2 != NULL && *cp2 != '\0';
 762                                     cp2 = strsep(&cp, ",")) {
 763                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 764                                                 fprintf(stderr, "Warning: "
 765                                                     "ignoring host name with "
 766                                                     "metacharacters: %.64s\n",
 767                                                     cp2);
 768                                         else
 769                                                 print_host(out, cp2, public, 1);
 770                                 }
 771                                 has_unhashed = 1;
 772                         }
 773                 }
 774                 key_free(public);
 775         }
 776         fclose(in);
 777
 778         if (invalid) {
 779                 fprintf(stderr, "%s is not a valid known_hosts file.\n",
 780                     identity_file);
 781                 if (inplace) {
 782                         fprintf(stderr, "Not replacing existing known_hosts "
 783                             "file because of errors\n");
 784                         fclose(out);
 785                         unlink(tmp);
 786                 }
 787                 exit(1);
 788         }
 789
 790         if (inplace) {
 791                 fclose(out);
 792
 793                 /* Backup existing file */
 794                 if (unlink(old) == -1 && errno != ENOENT)
 795                         fatal("unlink %.100s: %s", old, strerror(errno));
 796                 if (link(identity_file, old) == -1)
 797                         fatal("link %.100s to %.100s: %s", identity_file, old,
 798                             strerror(errno));
 799                 /* Move new one into place */
 800                 if (rename(tmp, identity_file) == -1) {
 801                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 802                             strerror(errno));
 803                         unlink(tmp);
 804                         unlink(old);
 805                         exit(1);
 806                 }
 807
 808                 fprintf(stderr, "%s updated.\n", identity_file);
 809                 fprintf(stderr, "Original contents retained as %s\n", old);
 810                 if (has_unhashed) {
 811                         fprintf(stderr, "WARNING: %s contains unhashed "
 812                             "entries\n", old);
 813                         fprintf(stderr, "Delete this file to ensure privacy "
 814                             "of hostnames\n");
 815                 }
 816         }
 817
 818         exit(0);
 819 }
 820
 821 /*
 822  * Perform changing a passphrase.  The argument is the passwd structure
 823  * for the current user.
 824  */
 825 static void
 826 do_change_passphrase(struct passwd *pw)
 827 {
 828         char *comment;
 829         char *old_passphrase, *passphrase1, *passphrase2;
 830         struct stat st;
 831         Key *private;
 832
 833         if (!have_identity)
 834                 ask_filename(pw, "Enter file in which the key is");
 835         if (stat(identity_file, &st) < 0) {
 836                 perror(identity_file);
 837                 exit(1);
 838         }
 839         /* Try to load the file with empty passphrase. */
 840         private = key_load_private(identity_file, "", &comment);
 841         if (private == NULL) {
 842                 if (identity_passphrase)
 843                         old_passphrase = xstrdup(identity_passphrase);
 844                 else
 845                         old_passphrase =
 846                             read_passphrase("Enter old passphrase: ",
 847                             RP_ALLOW_STDIN);
 848                 private = key_load_private(identity_file, old_passphrase,
 849                     &comment);
 850                 memset(old_passphrase, 0, strlen(old_passphrase));
 851                 xfree(old_passphrase);
 852                 if (private == NULL) {
 853                         printf("Bad passphrase.\n");
 854                         exit(1);
 855                 }
 856         }
 857         printf("Key has comment '%s'\n", comment);
 858
 859         /* Ask the new passphrase (twice). */
 860         if (identity_new_passphrase) {
 861                 passphrase1 = xstrdup(identity_new_passphrase);
 862                 passphrase2 = NULL;
 863         } else {
 864                 passphrase1 =
 865                         read_passphrase("Enter new passphrase (empty for no "
 866                             "passphrase): ", RP_ALLOW_STDIN);
 867                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 868                     RP_ALLOW_STDIN);
 869
 870                 /* Verify that they are the same. */
 871                 if (strcmp(passphrase1, passphrase2) != 0) {
 872                         memset(passphrase1, 0, strlen(passphrase1));
 873                         memset(passphrase2, 0, strlen(passphrase2));
 874                         xfree(passphrase1);
 875                         xfree(passphrase2);
 876                         printf("Pass phrases do not match.  Try again.\n");
 877                         exit(1);
 878                 }
 879                 /* Destroy the other copy. */
 880                 memset(passphrase2, 0, strlen(passphrase2));
 881                 xfree(passphrase2);
 882         }
 883
 884         /* Save the file using the new passphrase. */
 885         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 886                 printf("Saving the key failed: %s.\n", identity_file);
 887                 memset(passphrase1, 0, strlen(passphrase1));
 888                 xfree(passphrase1);
 889                 key_free(private);
 890                 xfree(comment);
 891                 exit(1);
 892         }
 893         /* Destroy the passphrase and the copy of the key in memory. */
 894         memset(passphrase1, 0, strlen(passphrase1));
 895         xfree(passphrase1);
 896         key_free(private);               /* Destroys contents */
 897         xfree(comment);
 898
 899         printf("Your identification has been saved with the new passphrase.\n");
 900         exit(0);
 901 }
 902
 903 /*
 904  * Print the SSHFP RR.
 905  */
 906 static int
 907 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 908 {
 909         Key *public;
 910         char *comment = NULL;
 911         struct stat st;
 912
 913         if (fname == NULL)
 914                 ask_filename(pw, "Enter file in which the key is");
 915         if (stat(fname, &st) < 0) {
 916                 if (errno == ENOENT)
 917                         return 0;
 918                 perror(fname);
 919                 exit(1);
 920         }
 921         public = key_load_public(fname, &comment);
 922         if (public != NULL) {
 923                 export_dns_rr(hname, public, stdout, print_generic);
 924                 key_free(public);
 925                 xfree(comment);
 926                 return 1;
 927         }
 928         if (comment)
 929                 xfree(comment);
 930
 931         printf("failed to read v2 public key from %s.\n", fname);
 932         exit(1);
 933 }
 934
 935 /*
 936  * Change the comment of a private key file.
 937  */
 938 static void
 939 do_change_comment(struct passwd *pw)
 940 {
 941         char new_comment[1024], *comment, *passphrase;
 942         Key *private;
 943         Key *public;
 944         struct stat st;
 945         FILE *f;
 946         int fd;
 947
 948         if (!have_identity)
 949                 ask_filename(pw, "Enter file in which the key is");
 950         if (stat(identity_file, &st) < 0) {
 951                 perror(identity_file);
 952                 exit(1);
 953         }
 954         private = key_load_private(identity_file, "", &comment);
 955         if (private == NULL) {
 956                 if (identity_passphrase)
 957                         passphrase = xstrdup(identity_passphrase);
 958                 else if (identity_new_passphrase)
 959                         passphrase = xstrdup(identity_new_passphrase);
 960                 else
 961                         passphrase = read_passphrase("Enter passphrase: ",
 962                             RP_ALLOW_STDIN);
 963                 /* Try to load using the passphrase. */
 964                 private = key_load_private(identity_file, passphrase, &comment);
 965                 if (private == NULL) {
 966                         memset(passphrase, 0, strlen(passphrase));
 967                         xfree(passphrase);
 968                         printf("Bad passphrase.\n");
 969                         exit(1);
 970                 }
 971         } else {
 972                 passphrase = xstrdup("");
 973         }
 974         if (private->type != KEY_RSA1) {
 975                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 976                 key_free(private);
 977                 exit(1);
 978         }
 979         printf("Key now has comment '%s'\n", comment);
 980
 981         if (identity_comment) {
 982                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 983         } else {
 984                 printf("Enter new comment: ");
 985                 fflush(stdout);
 986                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 987                         memset(passphrase, 0, strlen(passphrase));
 988                         key_free(private);
 989                         exit(1);
 990                 }
 991                 new_comment[strcspn(new_comment, "\n")] = '\0';
 992         }
 993
 994         /* Save the file using the new passphrase. */
 995         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 996                 printf("Saving the key failed: %s.\n", identity_file);
 997                 memset(passphrase, 0, strlen(passphrase));
 998                 xfree(passphrase);
 999                 key_free(private);
1000                 xfree(comment);
1001                 exit(1);
1002         }
1003         memset(passphrase, 0, strlen(passphrase));
1004         xfree(passphrase);
1005         public = key_from_private(private);
1006         key_free(private);
1007
1008         strlcat(identity_file, ".pub", sizeof(identity_file));
1009         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1010         if (fd == -1) {
1011                 printf("Could not save your public key in %s\n", identity_file);
1012                 exit(1);
1013         }
1014         f = fdopen(fd, "w");
1015         if (f == NULL) {
1016                 printf("fdopen %s failed", identity_file);
1017                 exit(1);
1018         }
1019         if (!key_write(public, f))
1020                 fprintf(stderr, "write key failed");
1021         key_free(public);
1022         fprintf(f, " %s\n", new_comment);
1023         fclose(f);
1024
1025         xfree(comment);
1026
1027         printf("The comment in your key file has been changed.\n");
1028         exit(0);
1029 }
1030
1031 static void
1032 usage(void)
1033 {
1034         fprintf(stderr, "usage: %s [options]\n", __progname);
1035         fprintf(stderr, "Options:\n");
1036         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1037         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1038         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1039         fprintf(stderr, "  -C comment  Provide new comment.\n");
1040         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1041 #ifdef SMARTCARD
1042         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1043 #endif /* SMARTCARD */
1044         fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
1045         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1046         fprintf(stderr, "  -f filename Filename of the key file.\n");
1047         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1048         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1049         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1050         fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
1051         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1052         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1053         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1054         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1055         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1056         fprintf(stderr, "  -q          Quiet.\n");
1057         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1058         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1059         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1060         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1061         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1062 #ifdef SMARTCARD
1063         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1064 #endif /* SMARTCARD */
1065         fprintf(stderr, "  -v          Verbose.\n");
1066         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1067         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1068
1069         exit(1);
1070 }
1071
1072 /*
1073  * Main program for key management.
1074  */
1075 int
1076 main(int argc, char **argv)
1077 {
1078         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1079         char out_file[MAXPATHLEN], *reader_id = NULL;
1080         char *rr_hostname = NULL;
1081         Key *private, *public;
1082         struct passwd *pw;
1083         struct stat st;
1084         int opt, type, fd, download = 0;
1085         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1086         int do_gen_candidates = 0, do_screen_candidates = 0;
1087         BIGNUM *start = NULL;
1088         FILE *f;
1089         const char *errstr;
1090
1091         extern int optind;
1092         extern char *optarg;
1093
1094         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1095         sanitise_stdfd();
1096
1097         __progname = ssh_get_progname(argv[0]);
1098
1099         SSLeay_add_all_algorithms();
1100         log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1101
1102         init_rng();
1103         seed_rng();
1104
1105         /* we need this for the home * directory.  */
1106         pw = getpwuid(getuid());
1107         if (!pw) {
1108                 printf("You don't exist, go away!\n");
1109                 exit(1);
1110         }
1111         if (gethostname(hostname, sizeof(hostname)) < 0) {
1112                 perror("gethostname");
1113                 exit(1);
1114         }
1115
1116         while ((opt = getopt(argc, argv,
1117             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1118                 switch (opt) {
1119                 case 'b':
1120                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1121                         if (errstr)
1122                                 fatal("Bits has bad value %s (%s)",
1123                                         optarg, errstr);
1124                         break;
1125                 case 'F':
1126                         find_host = 1;
1127                         rr_hostname = optarg;
1128                         break;
1129                 case 'H':
1130                         hash_hosts = 1;
1131                         break;
1132                 case 'R':
1133                         delete_host = 1;
1134                         rr_hostname = optarg;
1135                         break;
1136                 case 'l':
1137                         print_fingerprint = 1;
1138                         break;
1139                 case 'B':
1140                         print_bubblebabble = 1;
1141                         break;
1142                 case 'p':
1143                         change_passphrase = 1;
1144                         break;
1145                 case 'c':
1146                         change_comment = 1;
1147                         break;
1148                 case 'f':
1149                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1150                             sizeof(identity_file))
1151                                 fatal("Identity filename too long");
1152                         have_identity = 1;
1153                         break;
1154                 case 'g':
1155                         print_generic = 1;
1156                         break;
1157                 case 'P':
1158                         identity_passphrase = optarg;
1159                         break;
1160                 case 'N':
1161                         identity_new_passphrase = optarg;
1162                         break;
1163                 case 'C':
1164                         identity_comment = optarg;
1165                         break;
1166                 case 'q':
1167                         quiet = 1;
1168                         break;
1169                 case 'e':
1170                 case 'x':
1171                         /* export key */
1172                         convert_to_ssh2 = 1;
1173                         break;
1174                 case 'i':
1175                 case 'X':
1176                         /* import key */
1177                         convert_from_ssh2 = 1;
1178                         break;
1179                 case 'y':
1180                         print_public = 1;
1181                         break;
1182                 case 'd':
1183                         key_type_name = "dsa";
1184                         break;
1185                 case 't':
1186                         key_type_name = optarg;
1187                         break;
1188                 case 'D':
1189                         download = 1;
1190                         /*FALLTHROUGH*/
1191                 case 'U':
1192                         reader_id = optarg;
1193                         break;
1194                 case 'v':
1195                         if (log_level == SYSLOG_LEVEL_INFO)
1196                                 log_level = SYSLOG_LEVEL_DEBUG1;
1197                         else {
1198                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1199                                     log_level < SYSLOG_LEVEL_DEBUG3)
1200                                         log_level++;
1201                         }
1202                         break;
1203                 case 'r':
1204                         rr_hostname = optarg;
1205                         break;
1206                 case 'W':
1207                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1208                             UINT_MAX, &errstr);
1209                         if (errstr)
1210                                 fatal("Desired generator has bad value: %s (%s)",
1211                                         optarg, errstr);
1212                         break;
1213                 case 'a':
1214                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1215                         if (errstr)
1216                                 fatal("Invalid number of trials: %s (%s)",
1217                                         optarg, errstr);
1218                         break;
1219                 case 'M':
1220                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1221                         if (errstr) {
1222                                 fatal("Memory limit is %s: %s", errstr, optarg);
1223                         }
1224                         break;
1225                 case 'G':
1226                         do_gen_candidates = 1;
1227                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1228                             sizeof(out_file))
1229                                 fatal("Output filename too long");
1230                         break;
1231                 case 'T':
1232                         do_screen_candidates = 1;
1233                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1234                             sizeof(out_file))
1235                                 fatal("Output filename too long");
1236                         break;
1237                 case 'S':
1238                         /* XXX - also compare length against bits */
1239                         if (BN_hex2bn(&start, optarg) == 0)
1240                                 fatal("Invalid start point.");
1241                         break;
1242                 case '?':
1243                 default:
1244                         usage();
1245                 }
1246         }
1247
1248         /* reinit */
1249         log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
1250
1251         if (optind < argc) {
1252                 printf("Too many arguments.\n");
1253                 usage();
1254         }
1255         if (change_passphrase && change_comment) {
1256                 printf("Can only have one of -p and -c.\n");
1257                 usage();
1258         }
1259         if (print_fingerprint && (delete_host || hash_hosts)) {
1260                 printf("Cannot use -l with -D or -R.\n");
1261                 usage();
1262         }
1263         if (delete_host || hash_hosts || find_host)
1264                 do_known_hosts(pw, rr_hostname);
1265         if (print_fingerprint || print_bubblebabble)
1266                 do_fingerprint(pw);
1267         if (change_passphrase)
1268                 do_change_passphrase(pw);
1269         if (change_comment)
1270                 do_change_comment(pw);
1271         if (convert_to_ssh2)
1272                 do_convert_to_ssh2(pw);
1273         if (convert_from_ssh2)
1274                 do_convert_from_ssh2(pw);
1275         if (print_public)
1276                 do_print_public(pw);
1277         if (rr_hostname != NULL) {
1278                 unsigned int n = 0;
1279
1280                 if (have_identity) {
1281                         n = do_print_resource_record(pw,
1282                             identity_file, rr_hostname);
1283                         if (n == 0) {
1284                                 perror(identity_file);
1285                                 exit(1);
1286                         }
1287                         exit(0);
1288                 } else {
1289
1290                         n += do_print_resource_record(pw,
1291                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1292                         n += do_print_resource_record(pw,
1293                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1294
1295                         if (n == 0)
1296                                 fatal("no keys found.");
1297                         exit(0);
1298                 }
1299         }
1300         if (reader_id != NULL) {
1301 #ifdef SMARTCARD
1302                 if (download)
1303                         do_download(pw, reader_id);
1304                 else
1305                         do_upload(pw, reader_id);
1306 #else /* SMARTCARD */
1307                 fatal("no support for smartcards.");
1308 #endif /* SMARTCARD */
1309         }
1310
1311         if (do_gen_candidates) {
1312                 FILE *out = fopen(out_file, "w");
1313
1314                 if (out == NULL) {
1315                         error("Couldn't open modulus candidate file \"%s\": %s",
1316                             out_file, strerror(errno));
1317                         return (1);
1318                 }
1319                 if (bits == 0)
1320                         bits = DEFAULT_BITS;
1321                 if (gen_candidates(out, memory, bits, start) != 0)
1322                         fatal("modulus candidate generation failed");
1323
1324                 return (0);
1325         }
1326
1327         if (do_screen_candidates) {
1328                 FILE *in;
1329                 FILE *out = fopen(out_file, "w");
1330
1331                 if (have_identity && strcmp(identity_file, "-") != 0) {
1332                         if ((in = fopen(identity_file, "r")) == NULL) {
1333                                 fatal("Couldn't open modulus candidate "
1334                                     "file \"%s\": %s", identity_file,
1335                                     strerror(errno));
1336                         }
1337                 } else
1338                         in = stdin;
1339
1340                 if (out == NULL) {
1341                         fatal("Couldn't open moduli file \"%s\": %s",
1342                             out_file, strerror(errno));
1343                 }
1344                 if (prime_test(in, out, trials, generator_wanted) != 0)
1345                         fatal("modulus screening failed");
1346                 return (0);
1347         }
1348
1349         arc4random_stir();
1350
1351         if (key_type_name == NULL)
1352                 key_type_name = "rsa";
1353
1354         type = key_type_from_name(key_type_name);
1355         if (type == KEY_UNSPEC) {
1356                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1357                 exit(1);
1358         }
1359         if (bits == 0)
1360                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1361         if (type == KEY_DSA && bits != 1024)
1362                 fatal("DSA keys must be 1024 bits");
1363         if (!quiet)
1364                 printf("Generating public/private %s key pair.\n", key_type_name);
1365         private = key_generate(type, bits);
1366         if (private == NULL) {
1367                 fprintf(stderr, "key_generate failed");
1368                 exit(1);
1369         }
1370         public  = key_from_private(private);
1371
1372         if (!have_identity)
1373                 ask_filename(pw, "Enter file in which to save the key");
1374
1375         /* Create ~/.ssh directory if it doesn't already exist. */
1376         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1377         if (strstr(identity_file, dotsshdir) != NULL &&
1378             stat(dotsshdir, &st) < 0) {
1379                 if (mkdir(dotsshdir, 0700) < 0)
1380                         error("Could not create directory '%s'.", dotsshdir);
1381                 else if (!quiet)
1382                         printf("Created directory '%s'.\n", dotsshdir);
1383         }
1384         /* If the file already exists, ask the user to confirm. */
1385         if (stat(identity_file, &st) >= 0) {
1386                 char yesno[3];
1387                 printf("%s already exists.\n", identity_file);
1388                 printf("Overwrite (y/n)? ");
1389                 fflush(stdout);
1390                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1391                         exit(1);
1392                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1393                         exit(1);
1394         }
1395         /* Ask for a passphrase (twice). */
1396         if (identity_passphrase)
1397                 passphrase1 = xstrdup(identity_passphrase);
1398         else if (identity_new_passphrase)
1399                 passphrase1 = xstrdup(identity_new_passphrase);
1400         else {
1401 passphrase_again:
1402                 passphrase1 =
1403                         read_passphrase("Enter passphrase (empty for no "
1404                             "passphrase): ", RP_ALLOW_STDIN);
1405                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1406                     RP_ALLOW_STDIN);
1407                 if (strcmp(passphrase1, passphrase2) != 0) {
1408                         /*
1409                          * The passphrases do not match.  Clear them and
1410                          * retry.
1411                          */
1412                         memset(passphrase1, 0, strlen(passphrase1));
1413                         memset(passphrase2, 0, strlen(passphrase2));
1414                         xfree(passphrase1);
1415                         xfree(passphrase2);
1416                         printf("Passphrases do not match.  Try again.\n");
1417                         goto passphrase_again;
1418                 }
1419                 /* Clear the other copy of the passphrase. */
1420                 memset(passphrase2, 0, strlen(passphrase2));
1421                 xfree(passphrase2);
1422         }
1423
1424         if (identity_comment) {
1425                 strlcpy(comment, identity_comment, sizeof(comment));
1426         } else {
1427                 /* Create default commend field for the passphrase. */
1428                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1429         }
1430
1431         /* Save the key with the given passphrase and comment. */
1432         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1433                 printf("Saving the key failed: %s.\n", identity_file);
1434                 memset(passphrase1, 0, strlen(passphrase1));
1435                 xfree(passphrase1);
1436                 exit(1);
1437         }
1438         /* Clear the passphrase. */
1439         memset(passphrase1, 0, strlen(passphrase1));
1440         xfree(passphrase1);
1441
1442         /* Clear the private key and the random number generator. */
1443         key_free(private);
1444         arc4random_stir();
1445
1446         if (!quiet)
1447                 printf("Your identification has been saved in %s.\n", identity_file);
1448
1449         strlcat(identity_file, ".pub", sizeof(identity_file));
1450         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1451         if (fd == -1) {
1452                 printf("Could not save your public key in %s\n", identity_file);
1453                 exit(1);
1454         }
1455         f = fdopen(fd, "w");
1456         if (f == NULL) {
1457                 printf("fdopen %s failed", identity_file);
1458                 exit(1);
1459         }
1460         if (!key_write(public, f))
1461                 fprintf(stderr, "write key failed");
1462         fprintf(f, " %s\n", comment);
1463         fclose(f);
1464
1465         if (!quiet) {
1466                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1467                 char *ra = key_fingerprint(public, SSH_FP_MD5,
1468                     SSH_FP_RANDOMART);
1469                 printf("Your public key has been saved in %s.\n",
1470                     identity_file);
1471                 printf("The key fingerprint is:\n");
1472                 printf("%s %s\n", fp, comment);
1473                 printf("The key's randomart image is:\n");
1474                 printf("%s\n", ra);
1475                 xfree(ra);
1476                 xfree(fp);
1477         }
1478
1479         key_free(public);
1480         exit(0);
1481 }