ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.148 2006/07/11 20:07:25 stevesk Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Identity and host key generation and maintenance.
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  */
  14
  15 #include "includes.h"
  16
  17 #include <sys/types.h>
  18 #include <sys/socket.h>
  19 #include <sys/stat.h>
  20
  21 #include <openssl/evp.h>
  22 #include <openssl/pem.h>
  23
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #if defined(HAVE_NETDB_H)
  27 # include <netdb.h>
  28 #endif
  29 #ifdef HAVE_PATHS_H
  30 # include <paths.h>
  31 #endif
  32 #include <pwd.h>
  33
  34 #include "xmalloc.h"
  35 #include "key.h"
  36 #include "rsa.h"
  37 #include "authfile.h"
  38 #include "uuencode.h"
  39 #include "buffer.h"
  40 #include "bufaux.h"
  41 #include "pathnames.h"
  42 #include "log.h"
  43 #include "misc.h"
  44 #include "match.h"
  45 #include "hostfile.h"
  46 #include "dns.h"
  47
  48 #ifdef SMARTCARD
  49 #include "scard.h"
  50 #endif
  51
  52 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  53 #define DEFAULT_BITS            2048
  54 #define DEFAULT_BITS_DSA        1024
  55 u_int32_t bits = 0;
  56
  57 /*
  58  * Flag indicating that we just want to change the passphrase.  This can be
  59  * set on the command line.
  60  */
  61 int change_passphrase = 0;
  62
  63 /*
  64  * Flag indicating that we just want to change the comment.  This can be set
  65  * on the command line.
  66  */
  67 int change_comment = 0;
  68
  69 int quiet = 0;
  70
  71 /* Flag indicating that we want to hash a known_hosts file */
  72 int hash_hosts = 0;
  73 /* Flag indicating that we want lookup a host in known_hosts file */
  74 int find_host = 0;
  75 /* Flag indicating that we want to delete a host from a known_hosts file */
  76 int delete_host = 0;
  77
  78 /* Flag indicating that we just want to see the key fingerprint */
  79 int print_fingerprint = 0;
  80 int print_bubblebabble = 0;
  81
  82 /* The identity file name, given on the command line or entered by the user. */
  83 char identity_file[1024];
  84 int have_identity = 0;
  85
  86 /* This is set to the passphrase if given on the command line. */
  87 char *identity_passphrase = NULL;
  88
  89 /* This is set to the new passphrase if given on the command line. */
  90 char *identity_new_passphrase = NULL;
  91
  92 /* This is set to the new comment if given on the command line. */
  93 char *identity_comment = NULL;
  94
  95 /* Dump public key file in format used by real and the original SSH 2 */
  96 int convert_to_ssh2 = 0;
  97 int convert_from_ssh2 = 0;
  98 int print_public = 0;
  99 int print_generic = 0;
 100
 101 char *key_type_name = NULL;
 102
 103 /* argv0 */
 104 extern char *__progname;
 105
 106 char hostname[MAXHOSTNAMELEN];
 107
 108 /* moduli.c */
 109 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 110 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 111
 112 static void
 113 ask_filename(struct passwd *pw, const char *prompt)
 114 {
 115         char buf[1024];
 116         char *name = NULL;
 117
 118         if (key_type_name == NULL)
 119                 name = _PATH_SSH_CLIENT_ID_RSA;
 120         else {
 121                 switch (key_type_from_name(key_type_name)) {
 122                 case KEY_RSA1:
 123                         name = _PATH_SSH_CLIENT_IDENTITY;
 124                         break;
 125                 case KEY_DSA:
 126                         name = _PATH_SSH_CLIENT_ID_DSA;
 127                         break;
 128                 case KEY_RSA:
 129                         name = _PATH_SSH_CLIENT_ID_RSA;
 130                         break;
 131                 default:
 132                         fprintf(stderr, "bad key type");
 133                         exit(1);
 134                         break;
 135                 }
 136         }
 137         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 138         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 139         if (fgets(buf, sizeof(buf), stdin) == NULL)
 140                 exit(1);
 141         if (strchr(buf, '\n'))
 142                 *strchr(buf, '\n') = 0;
 143         if (strcmp(buf, "") != 0)
 144                 strlcpy(identity_file, buf, sizeof(identity_file));
 145         have_identity = 1;
 146 }
 147
 148 static Key *
 149 load_identity(char *filename)
 150 {
 151         char *pass;
 152         Key *prv;
 153
 154         prv = key_load_private(filename, "", NULL);
 155         if (prv == NULL) {
 156                 if (identity_passphrase)
 157                         pass = xstrdup(identity_passphrase);
 158                 else
 159                         pass = read_passphrase("Enter passphrase: ",
 160                             RP_ALLOW_STDIN);
 161                 prv = key_load_private(filename, pass, NULL);
 162                 memset(pass, 0, strlen(pass));
 163                 xfree(pass);
 164         }
 165         return prv;
 166 }
 167
 168 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 169 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 170 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 171 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 172
 173 static void
 174 do_convert_to_ssh2(struct passwd *pw)
 175 {
 176         Key *k;
 177         u_int len;
 178         u_char *blob;
 179         struct stat st;
 180
 181         if (!have_identity)
 182                 ask_filename(pw, "Enter file in which the key is");
 183         if (stat(identity_file, &st) < 0) {
 184                 perror(identity_file);
 185                 exit(1);
 186         }
 187         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 188                 if ((k = load_identity(identity_file)) == NULL) {
 189                         fprintf(stderr, "load failed\n");
 190                         exit(1);
 191                 }
 192         }
 193         if (k->type == KEY_RSA1) {
 194                 fprintf(stderr, "version 1 keys are not supported\n");
 195                 exit(1);
 196         }
 197         if (key_to_blob(k, &blob, &len) <= 0) {
 198                 fprintf(stderr, "key_to_blob failed\n");
 199                 exit(1);
 200         }
 201         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 202         fprintf(stdout,
 203             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 204             key_size(k), key_type(k),
 205             pw->pw_name, hostname);
 206         dump_base64(stdout, blob, len);
 207         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 208         key_free(k);
 209         xfree(blob);
 210         exit(0);
 211 }
 212
 213 static void
 214 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 215 {
 216         u_int bignum_bits = buffer_get_int(b);
 217         u_int bytes = (bignum_bits + 7) / 8;
 218
 219         if (buffer_len(b) < bytes)
 220                 fatal("buffer_get_bignum_bits: input buffer too small: "
 221                     "need %d have %d", bytes, buffer_len(b));
 222         BN_bin2bn(buffer_ptr(b), bytes, value);
 223         buffer_consume(b, bytes);
 224 }
 225
 226 static Key *
 227 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 228 {
 229         Buffer b;
 230         Key *key = NULL;
 231         char *type, *cipher;
 232         u_char *sig, data[] = "abcde12345";
 233         int magic, rlen, ktype, i1, i2, i3, i4;
 234         u_int slen;
 235         u_long e;
 236
 237         buffer_init(&b);
 238         buffer_append(&b, blob, blen);
 239
 240         magic  = buffer_get_int(&b);
 241         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 242                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 243                 buffer_free(&b);
 244                 return NULL;
 245         }
 246         i1 = buffer_get_int(&b);
 247         type   = buffer_get_string(&b, NULL);
 248         cipher = buffer_get_string(&b, NULL);
 249         i2 = buffer_get_int(&b);
 250         i3 = buffer_get_int(&b);
 251         i4 = buffer_get_int(&b);
 252         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 253         if (strcmp(cipher, "none") != 0) {
 254                 error("unsupported cipher %s", cipher);
 255                 xfree(cipher);
 256                 buffer_free(&b);
 257                 xfree(type);
 258                 return NULL;
 259         }
 260         xfree(cipher);
 261
 262         if (strstr(type, "dsa")) {
 263                 ktype = KEY_DSA;
 264         } else if (strstr(type, "rsa")) {
 265                 ktype = KEY_RSA;
 266         } else {
 267                 buffer_free(&b);
 268                 xfree(type);
 269                 return NULL;
 270         }
 271         key = key_new_private(ktype);
 272         xfree(type);
 273
 274         switch (key->type) {
 275         case KEY_DSA:
 276                 buffer_get_bignum_bits(&b, key->dsa->p);
 277                 buffer_get_bignum_bits(&b, key->dsa->g);
 278                 buffer_get_bignum_bits(&b, key->dsa->q);
 279                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 280                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 281                 break;
 282         case KEY_RSA:
 283                 e  = buffer_get_char(&b);
 284                 debug("e %lx", e);
 285                 if (e < 30) {
 286                         e <<= 8;
 287                         e += buffer_get_char(&b);
 288                         debug("e %lx", e);
 289                         e <<= 8;
 290                         e += buffer_get_char(&b);
 291                         debug("e %lx", e);
 292                 }
 293                 if (!BN_set_word(key->rsa->e, e)) {
 294                         buffer_free(&b);
 295                         key_free(key);
 296                         return NULL;
 297                 }
 298                 buffer_get_bignum_bits(&b, key->rsa->d);
 299                 buffer_get_bignum_bits(&b, key->rsa->n);
 300                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 301                 buffer_get_bignum_bits(&b, key->rsa->q);
 302                 buffer_get_bignum_bits(&b, key->rsa->p);
 303                 rsa_generate_additional_parameters(key->rsa);
 304                 break;
 305         }
 306         rlen = buffer_len(&b);
 307         if (rlen != 0)
 308                 error("do_convert_private_ssh2_from_blob: "
 309                     "remaining bytes in key blob %d", rlen);
 310         buffer_free(&b);
 311
 312         /* try the key */
 313         key_sign(key, &sig, &slen, data, sizeof(data));
 314         key_verify(key, sig, slen, data, sizeof(data));
 315         xfree(sig);
 316         return key;
 317 }
 318
 319 static int
 320 get_line(FILE *fp, char *line, size_t len)
 321 {
 322         int c;
 323         size_t pos = 0;
 324
 325         line[0] = '\0';
 326         while ((c = fgetc(fp)) != EOF) {
 327                 if (pos >= len - 1) {
 328                         fprintf(stderr, "input line too long.\n");
 329                         exit(1);
 330                 }
 331                 switch (c) {
 332                 case '\r':
 333                         c = fgetc(fp);
 334                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 335                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 336                                 exit(1);
 337                         }
 338                         return pos;
 339                 case '\n':
 340                         return pos;
 341                 }
 342                 line[pos++] = c;
 343                 line[pos] = '\0';
 344         }
 345         if (c == EOF)
 346                 return -1;
 347         return pos;
 348 }
 349
 350 static void
 351 do_convert_from_ssh2(struct passwd *pw)
 352 {
 353         Key *k;
 354         int blen;
 355         u_int len;
 356         char line[1024];
 357         u_char blob[8096];
 358         char encoded[8096];
 359         struct stat st;
 360         int escaped = 0, private = 0, ok;
 361         FILE *fp;
 362
 363         if (!have_identity)
 364                 ask_filename(pw, "Enter file in which the key is");
 365         if (stat(identity_file, &st) < 0) {
 366                 perror(identity_file);
 367                 exit(1);
 368         }
 369         fp = fopen(identity_file, "r");
 370         if (fp == NULL) {
 371                 perror(identity_file);
 372                 exit(1);
 373         }
 374         encoded[0] = '\0';
 375         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 376                 if (line[blen - 1] == '\\')
 377                         escaped++;
 378                 if (strncmp(line, "----", 4) == 0 ||
 379                     strstr(line, ": ") != NULL) {
 380                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 381                                 private = 1;
 382                         if (strstr(line, " END ") != NULL) {
 383                                 break;
 384                         }
 385                         /* fprintf(stderr, "ignore: %s", line); */
 386                         continue;
 387                 }
 388                 if (escaped) {
 389                         escaped--;
 390                         /* fprintf(stderr, "escaped: %s", line); */
 391                         continue;
 392                 }
 393                 strlcat(encoded, line, sizeof(encoded));
 394         }
 395         len = strlen(encoded);
 396         if (((len % 4) == 3) &&
 397             (encoded[len-1] == '=') &&
 398             (encoded[len-2] == '=') &&
 399             (encoded[len-3] == '='))
 400                 encoded[len-3] = '\0';
 401         blen = uudecode(encoded, blob, sizeof(blob));
 402         if (blen < 0) {
 403                 fprintf(stderr, "uudecode failed.\n");
 404                 exit(1);
 405         }
 406         k = private ?
 407             do_convert_private_ssh2_from_blob(blob, blen) :
 408             key_from_blob(blob, blen);
 409         if (k == NULL) {
 410                 fprintf(stderr, "decode blob failed.\n");
 411                 exit(1);
 412         }
 413         ok = private ?
 414             (k->type == KEY_DSA ?
 415                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 416                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 417             key_write(k, stdout);
 418         if (!ok) {
 419                 fprintf(stderr, "key write failed");
 420                 exit(1);
 421         }
 422         key_free(k);
 423         if (!private)
 424                 fprintf(stdout, "\n");
 425         fclose(fp);
 426         exit(0);
 427 }
 428
 429 static void
 430 do_print_public(struct passwd *pw)
 431 {
 432         Key *prv;
 433         struct stat st;
 434
 435         if (!have_identity)
 436                 ask_filename(pw, "Enter file in which the key is");
 437         if (stat(identity_file, &st) < 0) {
 438                 perror(identity_file);
 439                 exit(1);
 440         }
 441         prv = load_identity(identity_file);
 442         if (prv == NULL) {
 443                 fprintf(stderr, "load failed\n");
 444                 exit(1);
 445         }
 446         if (!key_write(prv, stdout))
 447                 fprintf(stderr, "key_write failed");
 448         key_free(prv);
 449         fprintf(stdout, "\n");
 450         exit(0);
 451 }
 452
 453 #ifdef SMARTCARD
 454 static void
 455 do_upload(struct passwd *pw, const char *sc_reader_id)
 456 {
 457         Key *prv = NULL;
 458         struct stat st;
 459         int ret;
 460
 461         if (!have_identity)
 462                 ask_filename(pw, "Enter file in which the key is");
 463         if (stat(identity_file, &st) < 0) {
 464                 perror(identity_file);
 465                 exit(1);
 466         }
 467         prv = load_identity(identity_file);
 468         if (prv == NULL) {
 469                 error("load failed");
 470                 exit(1);
 471         }
 472         ret = sc_put_key(prv, sc_reader_id);
 473         key_free(prv);
 474         if (ret < 0)
 475                 exit(1);
 476         logit("loading key done");
 477         exit(0);
 478 }
 479
 480 static void
 481 do_download(struct passwd *pw, const char *sc_reader_id)
 482 {
 483         Key **keys = NULL;
 484         int i;
 485
 486         keys = sc_get_keys(sc_reader_id, NULL);
 487         if (keys == NULL)
 488                 fatal("cannot read public key from smartcard");
 489         for (i = 0; keys[i]; i++) {
 490                 key_write(keys[i], stdout);
 491                 key_free(keys[i]);
 492                 fprintf(stdout, "\n");
 493         }
 494         xfree(keys);
 495         exit(0);
 496 }
 497 #endif /* SMARTCARD */
 498
 499 static void
 500 do_fingerprint(struct passwd *pw)
 501 {
 502         FILE *f;
 503         Key *public;
 504         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 505         int i, skip = 0, num = 1, invalid = 1;
 506         enum fp_rep rep;
 507         enum fp_type fptype;
 508         struct stat st;
 509
 510         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 511         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 512
 513         if (!have_identity)
 514                 ask_filename(pw, "Enter file in which the key is");
 515         if (stat(identity_file, &st) < 0) {
 516                 perror(identity_file);
 517                 exit(1);
 518         }
 519         public = key_load_public(identity_file, &comment);
 520         if (public != NULL) {
 521                 fp = key_fingerprint(public, fptype, rep);
 522                 printf("%u %s %s\n", key_size(public), fp, comment);
 523                 key_free(public);
 524                 xfree(comment);
 525                 xfree(fp);
 526                 exit(0);
 527         }
 528         if (comment) {
 529                 xfree(comment);
 530                 comment = NULL;
 531         }
 532
 533         f = fopen(identity_file, "r");
 534         if (f != NULL) {
 535                 while (fgets(line, sizeof(line), f)) {
 536                         i = strlen(line) - 1;
 537                         if (line[i] != '\n') {
 538                                 error("line %d too long: %.40s...", num, line);
 539                                 skip = 1;
 540                                 continue;
 541                         }
 542                         num++;
 543                         if (skip) {
 544                                 skip = 0;
 545                                 continue;
 546                         }
 547                         line[i] = '\0';
 548
 549                         /* Skip leading whitespace, empty and comment lines. */
 550                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 551                                 ;
 552                         if (!*cp || *cp == '\n' || *cp == '#')
 553                                 continue ;
 554                         i = strtol(cp, &ep, 10);
 555                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 556                                 int quoted = 0;
 557                                 comment = cp;
 558                                 for (; *cp && (quoted || (*cp != ' ' &&
 559                                     *cp != '\t')); cp++) {
 560                                         if (*cp == '\\' && cp[1] == '"')
 561                                                 cp++;   /* Skip both */
 562                                         else if (*cp == '"')
 563                                                 quoted = !quoted;
 564                                 }
 565                                 if (!*cp)
 566                                         continue;
 567                                 *cp++ = '\0';
 568                         }
 569                         ep = cp;
 570                         public = key_new(KEY_RSA1);
 571                         if (key_read(public, &cp) != 1) {
 572                                 cp = ep;
 573                                 key_free(public);
 574                                 public = key_new(KEY_UNSPEC);
 575                                 if (key_read(public, &cp) != 1) {
 576                                         key_free(public);
 577                                         continue;
 578                                 }
 579                         }
 580                         comment = *cp ? cp : comment;
 581                         fp = key_fingerprint(public, fptype, rep);
 582                         printf("%u %s %s\n", key_size(public), fp,
 583                             comment ? comment : "no comment");
 584                         xfree(fp);
 585                         key_free(public);
 586                         invalid = 0;
 587                 }
 588                 fclose(f);
 589         }
 590         if (invalid) {
 591                 printf("%s is not a public key file.\n", identity_file);
 592                 exit(1);
 593         }
 594         exit(0);
 595 }
 596
 597 static void
 598 print_host(FILE *f, char *name, Key *public, int hash)
 599 {
 600         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 601                 fatal("hash_host failed");
 602         fprintf(f, "%s ", name);
 603         if (!key_write(public, f))
 604                 fatal("key_write failed");
 605         fprintf(f, "\n");
 606 }
 607
 608 static void
 609 do_known_hosts(struct passwd *pw, const char *name)
 610 {
 611         FILE *in, *out = stdout;
 612         Key *public;
 613         char *cp, *cp2, *kp, *kp2;
 614         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 615         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 616
 617         if (!have_identity) {
 618                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 619                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 620                     sizeof(identity_file))
 621                         fatal("Specified known hosts path too long");
 622                 xfree(cp);
 623                 have_identity = 1;
 624         }
 625         if ((in = fopen(identity_file, "r")) == NULL)
 626                 fatal("fopen: %s", strerror(errno));
 627
 628         /*
 629          * Find hosts goes to stdout, hash and deletions happen in-place
 630          * A corner case is ssh-keygen -HF foo, which should go to stdout
 631          */
 632         if (!find_host && (hash_hosts || delete_host)) {
 633                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 634                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 635                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 636                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 637                         fatal("known_hosts path too long");
 638                 umask(077);
 639                 if ((c = mkstemp(tmp)) == -1)
 640                         fatal("mkstemp: %s", strerror(errno));
 641                 if ((out = fdopen(c, "w")) == NULL) {
 642                         c = errno;
 643                         unlink(tmp);
 644                         fatal("fdopen: %s", strerror(c));
 645                 }
 646                 inplace = 1;
 647         }
 648
 649         while (fgets(line, sizeof(line), in)) {
 650                 num++;
 651                 i = strlen(line) - 1;
 652                 if (line[i] != '\n') {
 653                         error("line %d too long: %.40s...", num, line);
 654                         skip = 1;
 655                         invalid = 1;
 656                         continue;
 657                 }
 658                 if (skip) {
 659                         skip = 0;
 660                         continue;
 661                 }
 662                 line[i] = '\0';
 663
 664                 /* Skip leading whitespace, empty and comment lines. */
 665                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 666                         ;
 667                 if (!*cp || *cp == '\n' || *cp == '#') {
 668                         if (inplace)
 669                                 fprintf(out, "%s\n", cp);
 670                         continue;
 671                 }
 672                 /* Find the end of the host name portion. */
 673                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 674                         ;
 675                 if (*kp == '\0' || *(kp + 1) == '\0') {
 676                         error("line %d missing key: %.40s...",
 677                             num, line);
 678                         invalid = 1;
 679                         continue;
 680                 }
 681                 *kp++ = '\0';
 682                 kp2 = kp;
 683
 684                 public = key_new(KEY_RSA1);
 685                 if (key_read(public, &kp) != 1) {
 686                         kp = kp2;
 687                         key_free(public);
 688                         public = key_new(KEY_UNSPEC);
 689                         if (key_read(public, &kp) != 1) {
 690                                 error("line %d invalid key: %.40s...",
 691                                     num, line);
 692                                 key_free(public);
 693                                 invalid = 1;
 694                                 continue;
 695                         }
 696                 }
 697
 698                 if (*cp == HASH_DELIM) {
 699                         if (find_host || delete_host) {
 700                                 cp2 = host_hash(name, cp, strlen(cp));
 701                                 if (cp2 == NULL) {
 702                                         error("line %d: invalid hashed "
 703                                             "name: %.64s...", num, line);
 704                                         invalid = 1;
 705                                         continue;
 706                                 }
 707                                 c = (strcmp(cp2, cp) == 0);
 708                                 if (find_host && c) {
 709                                         printf("# Host %s found: "
 710                                             "line %d type %s\n", name,
 711                                             num, key_type(public));
 712                                         print_host(out, cp, public, 0);
 713                                 }
 714                                 if (delete_host && !c)
 715                                         print_host(out, cp, public, 0);
 716                         } else if (hash_hosts)
 717                                 print_host(out, cp, public, 0);
 718                 } else {
 719                         if (find_host || delete_host) {
 720                                 c = (match_hostname(name, cp,
 721                                     strlen(cp)) == 1);
 722                                 if (find_host && c) {
 723                                         printf("# Host %s found: "
 724                                             "line %d type %s\n", name,
 725                                             num, key_type(public));
 726                                         print_host(out, cp, public, hash_hosts);
 727                                 }
 728                                 if (delete_host && !c)
 729                                         print_host(out, cp, public, 0);
 730                         } else if (hash_hosts) {
 731                                 for (cp2 = strsep(&cp, ",");
 732                                     cp2 != NULL && *cp2 != '\0';
 733                                     cp2 = strsep(&cp, ",")) {
 734                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 735                                                 fprintf(stderr, "Warning: "
 736                                                     "ignoring host name with "
 737                                                     "metacharacters: %.64s\n",
 738                                                     cp2);
 739                                         else
 740                                                 print_host(out, cp2, public, 1);
 741                                 }
 742                                 has_unhashed = 1;
 743                         }
 744                 }
 745                 key_free(public);
 746         }
 747         fclose(in);
 748
 749         if (invalid) {
 750                 fprintf(stderr, "%s is not a valid known_host file.\n",
 751                     identity_file);
 752                 if (inplace) {
 753                         fprintf(stderr, "Not replacing existing known_hosts "
 754                             "file because of errors\n");
 755                         fclose(out);
 756                         unlink(tmp);
 757                 }
 758                 exit(1);
 759         }
 760
 761         if (inplace) {
 762                 fclose(out);
 763
 764                 /* Backup existing file */
 765                 if (unlink(old) == -1 && errno != ENOENT)
 766                         fatal("unlink %.100s: %s", old, strerror(errno));
 767                 if (link(identity_file, old) == -1)
 768                         fatal("link %.100s to %.100s: %s", identity_file, old,
 769                             strerror(errno));
 770                 /* Move new one into place */
 771                 if (rename(tmp, identity_file) == -1) {
 772                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 773                             strerror(errno));
 774                         unlink(tmp);
 775                         unlink(old);
 776                         exit(1);
 777                 }
 778
 779                 fprintf(stderr, "%s updated.\n", identity_file);
 780                 fprintf(stderr, "Original contents retained as %s\n", old);
 781                 if (has_unhashed) {
 782                         fprintf(stderr, "WARNING: %s contains unhashed "
 783                             "entries\n", old);
 784                         fprintf(stderr, "Delete this file to ensure privacy "
 785                             "of hostnames\n");
 786                 }
 787         }
 788
 789         exit(0);
 790 }
 791
 792 /*
 793  * Perform changing a passphrase.  The argument is the passwd structure
 794  * for the current user.
 795  */
 796 static void
 797 do_change_passphrase(struct passwd *pw)
 798 {
 799         char *comment;
 800         char *old_passphrase, *passphrase1, *passphrase2;
 801         struct stat st;
 802         Key *private;
 803
 804         if (!have_identity)
 805                 ask_filename(pw, "Enter file in which the key is");
 806         if (stat(identity_file, &st) < 0) {
 807                 perror(identity_file);
 808                 exit(1);
 809         }
 810         /* Try to load the file with empty passphrase. */
 811         private = key_load_private(identity_file, "", &comment);
 812         if (private == NULL) {
 813                 if (identity_passphrase)
 814                         old_passphrase = xstrdup(identity_passphrase);
 815                 else
 816                         old_passphrase =
 817                             read_passphrase("Enter old passphrase: ",
 818                             RP_ALLOW_STDIN);
 819                 private = key_load_private(identity_file, old_passphrase,
 820                     &comment);
 821                 memset(old_passphrase, 0, strlen(old_passphrase));
 822                 xfree(old_passphrase);
 823                 if (private == NULL) {
 824                         printf("Bad passphrase.\n");
 825                         exit(1);
 826                 }
 827         }
 828         printf("Key has comment '%s'\n", comment);
 829
 830         /* Ask the new passphrase (twice). */
 831         if (identity_new_passphrase) {
 832                 passphrase1 = xstrdup(identity_new_passphrase);
 833                 passphrase2 = NULL;
 834         } else {
 835                 passphrase1 =
 836                         read_passphrase("Enter new passphrase (empty for no "
 837                             "passphrase): ", RP_ALLOW_STDIN);
 838                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 839                     RP_ALLOW_STDIN);
 840
 841                 /* Verify that they are the same. */
 842                 if (strcmp(passphrase1, passphrase2) != 0) {
 843                         memset(passphrase1, 0, strlen(passphrase1));
 844                         memset(passphrase2, 0, strlen(passphrase2));
 845                         xfree(passphrase1);
 846                         xfree(passphrase2);
 847                         printf("Pass phrases do not match.  Try again.\n");
 848                         exit(1);
 849                 }
 850                 /* Destroy the other copy. */
 851                 memset(passphrase2, 0, strlen(passphrase2));
 852                 xfree(passphrase2);
 853         }
 854
 855         /* Save the file using the new passphrase. */
 856         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 857                 printf("Saving the key failed: %s.\n", identity_file);
 858                 memset(passphrase1, 0, strlen(passphrase1));
 859                 xfree(passphrase1);
 860                 key_free(private);
 861                 xfree(comment);
 862                 exit(1);
 863         }
 864         /* Destroy the passphrase and the copy of the key in memory. */
 865         memset(passphrase1, 0, strlen(passphrase1));
 866         xfree(passphrase1);
 867         key_free(private);               /* Destroys contents */
 868         xfree(comment);
 869
 870         printf("Your identification has been saved with the new passphrase.\n");
 871         exit(0);
 872 }
 873
 874 /*
 875  * Print the SSHFP RR.
 876  */
 877 static int
 878 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 879 {
 880         Key *public;
 881         char *comment = NULL;
 882         struct stat st;
 883
 884         if (fname == NULL)
 885                 ask_filename(pw, "Enter file in which the key is");
 886         if (stat(fname, &st) < 0) {
 887                 if (errno == ENOENT)
 888                         return 0;
 889                 perror(fname);
 890                 exit(1);
 891         }
 892         public = key_load_public(fname, &comment);
 893         if (public != NULL) {
 894                 export_dns_rr(hname, public, stdout, print_generic);
 895                 key_free(public);
 896                 xfree(comment);
 897                 return 1;
 898         }
 899         if (comment)
 900                 xfree(comment);
 901
 902         printf("failed to read v2 public key from %s.\n", fname);
 903         exit(1);
 904 }
 905
 906 /*
 907  * Change the comment of a private key file.
 908  */
 909 static void
 910 do_change_comment(struct passwd *pw)
 911 {
 912         char new_comment[1024], *comment, *passphrase;
 913         Key *private;
 914         Key *public;
 915         struct stat st;
 916         FILE *f;
 917         int fd;
 918
 919         if (!have_identity)
 920                 ask_filename(pw, "Enter file in which the key is");
 921         if (stat(identity_file, &st) < 0) {
 922                 perror(identity_file);
 923                 exit(1);
 924         }
 925         private = key_load_private(identity_file, "", &comment);
 926         if (private == NULL) {
 927                 if (identity_passphrase)
 928                         passphrase = xstrdup(identity_passphrase);
 929                 else if (identity_new_passphrase)
 930                         passphrase = xstrdup(identity_new_passphrase);
 931                 else
 932                         passphrase = read_passphrase("Enter passphrase: ",
 933                             RP_ALLOW_STDIN);
 934                 /* Try to load using the passphrase. */
 935                 private = key_load_private(identity_file, passphrase, &comment);
 936                 if (private == NULL) {
 937                         memset(passphrase, 0, strlen(passphrase));
 938                         xfree(passphrase);
 939                         printf("Bad passphrase.\n");
 940                         exit(1);
 941                 }
 942         } else {
 943                 passphrase = xstrdup("");
 944         }
 945         if (private->type != KEY_RSA1) {
 946                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 947                 key_free(private);
 948                 exit(1);
 949         }
 950         printf("Key now has comment '%s'\n", comment);
 951
 952         if (identity_comment) {
 953                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 954         } else {
 955                 printf("Enter new comment: ");
 956                 fflush(stdout);
 957                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 958                         memset(passphrase, 0, strlen(passphrase));
 959                         key_free(private);
 960                         exit(1);
 961                 }
 962                 if (strchr(new_comment, '\n'))
 963                         *strchr(new_comment, '\n') = 0;
 964         }
 965
 966         /* Save the file using the new passphrase. */
 967         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 968                 printf("Saving the key failed: %s.\n", identity_file);
 969                 memset(passphrase, 0, strlen(passphrase));
 970                 xfree(passphrase);
 971                 key_free(private);
 972                 xfree(comment);
 973                 exit(1);
 974         }
 975         memset(passphrase, 0, strlen(passphrase));
 976         xfree(passphrase);
 977         public = key_from_private(private);
 978         key_free(private);
 979
 980         strlcat(identity_file, ".pub", sizeof(identity_file));
 981         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 982         if (fd == -1) {
 983                 printf("Could not save your public key in %s\n", identity_file);
 984                 exit(1);
 985         }
 986         f = fdopen(fd, "w");
 987         if (f == NULL) {
 988                 printf("fdopen %s failed", identity_file);
 989                 exit(1);
 990         }
 991         if (!key_write(public, f))
 992                 fprintf(stderr, "write key failed");
 993         key_free(public);
 994         fprintf(f, " %s\n", new_comment);
 995         fclose(f);
 996
 997         xfree(comment);
 998
 999         printf("The comment in your key file has been changed.\n");
1000         exit(0);
1001 }
1002
1003 static void
1004 usage(void)
1005 {
1006         fprintf(stderr, "Usage: %s [options]\n", __progname);
1007         fprintf(stderr, "Options:\n");
1008         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1009         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1010         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1011         fprintf(stderr, "  -C comment  Provide new comment.\n");
1012         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1013 #ifdef SMARTCARD
1014         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1015 #endif /* SMARTCARD */
1016         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1017         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1018         fprintf(stderr, "  -f filename Filename of the key file.\n");
1019         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1020         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1021         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1022         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1023         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1024         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1025         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1026         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1027         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1028         fprintf(stderr, "  -q          Quiet.\n");
1029         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1030         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1031         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1032         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1033         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1034 #ifdef SMARTCARD
1035         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1036 #endif /* SMARTCARD */
1037         fprintf(stderr, "  -v          Verbose.\n");
1038         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1039         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1040
1041         exit(1);
1042 }
1043
1044 /*
1045  * Main program for key management.
1046  */
1047 int
1048 main(int ac, char **av)
1049 {
1050         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1051         char out_file[MAXPATHLEN], *reader_id = NULL;
1052         char *rr_hostname = NULL;
1053         Key *private, *public;
1054         struct passwd *pw;
1055         struct stat st;
1056         int opt, type, fd, download = 0;
1057         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1058         int do_gen_candidates = 0, do_screen_candidates = 0;
1059         int log_level = SYSLOG_LEVEL_INFO;
1060         BIGNUM *start = NULL;
1061         FILE *f;
1062         const char *errstr;
1063
1064         extern int optind;
1065         extern char *optarg;
1066
1067         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1068         sanitise_stdfd();
1069
1070         __progname = ssh_get_progname(av[0]);
1071
1072         SSLeay_add_all_algorithms();
1073         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1074
1075         init_rng();
1076         seed_rng();
1077
1078         /* we need this for the home * directory.  */
1079         pw = getpwuid(getuid());
1080         if (!pw) {
1081                 printf("You don't exist, go away!\n");
1082                 exit(1);
1083         }
1084         if (gethostname(hostname, sizeof(hostname)) < 0) {
1085                 perror("gethostname");
1086                 exit(1);
1087         }
1088
1089         while ((opt = getopt(ac, av,
1090             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1091                 switch (opt) {
1092                 case 'b':
1093                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1094                         if (errstr)
1095                                 fatal("Bits has bad value %s (%s)",
1096                                         optarg, errstr);
1097                         break;
1098                 case 'F':
1099                         find_host = 1;
1100                         rr_hostname = optarg;
1101                         break;
1102                 case 'H':
1103                         hash_hosts = 1;
1104                         break;
1105                 case 'R':
1106                         delete_host = 1;
1107                         rr_hostname = optarg;
1108                         break;
1109                 case 'l':
1110                         print_fingerprint = 1;
1111                         break;
1112                 case 'B':
1113                         print_bubblebabble = 1;
1114                         break;
1115                 case 'p':
1116                         change_passphrase = 1;
1117                         break;
1118                 case 'c':
1119                         change_comment = 1;
1120                         break;
1121                 case 'f':
1122                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1123                             sizeof(identity_file))
1124                                 fatal("Identity filename too long");
1125                         have_identity = 1;
1126                         break;
1127                 case 'g':
1128                         print_generic = 1;
1129                         break;
1130                 case 'P':
1131                         identity_passphrase = optarg;
1132                         break;
1133                 case 'N':
1134                         identity_new_passphrase = optarg;
1135                         break;
1136                 case 'C':
1137                         identity_comment = optarg;
1138                         break;
1139                 case 'q':
1140                         quiet = 1;
1141                         break;
1142                 case 'e':
1143                 case 'x':
1144                         /* export key */
1145                         convert_to_ssh2 = 1;
1146                         break;
1147                 case 'i':
1148                 case 'X':
1149                         /* import key */
1150                         convert_from_ssh2 = 1;
1151                         break;
1152                 case 'y':
1153                         print_public = 1;
1154                         break;
1155                 case 'd':
1156                         key_type_name = "dsa";
1157                         break;
1158                 case 't':
1159                         key_type_name = optarg;
1160                         break;
1161                 case 'D':
1162                         download = 1;
1163                         /*FALLTHROUGH*/
1164                 case 'U':
1165                         reader_id = optarg;
1166                         break;
1167                 case 'v':
1168                         if (log_level == SYSLOG_LEVEL_INFO)
1169                                 log_level = SYSLOG_LEVEL_DEBUG1;
1170                         else {
1171                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1172                                     log_level < SYSLOG_LEVEL_DEBUG3)
1173                                         log_level++;
1174                         }
1175                         break;
1176                 case 'r':
1177                         rr_hostname = optarg;
1178                         break;
1179                 case 'W':
1180                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1181                             UINT_MAX, &errstr);
1182                         if (errstr)
1183                                 fatal("Desired generator has bad value: %s (%s)",
1184                                         optarg, errstr);
1185                         break;
1186                 case 'a':
1187                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1188                         if (errstr)
1189                                 fatal("Invalid number of trials: %s (%s)",
1190                                         optarg, errstr);
1191                         break;
1192                 case 'M':
1193                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1194                         if (errstr) {
1195                                 fatal("Memory limit is %s: %s", errstr, optarg);
1196                         }
1197                         break;
1198                 case 'G':
1199                         do_gen_candidates = 1;
1200                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1201                             sizeof(out_file))
1202                                 fatal("Output filename too long");
1203                         break;
1204                 case 'T':
1205                         do_screen_candidates = 1;
1206                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1207                             sizeof(out_file))
1208                                 fatal("Output filename too long");
1209                         break;
1210                 case 'S':
1211                         /* XXX - also compare length against bits */
1212                         if (BN_hex2bn(&start, optarg) == 0)
1213                                 fatal("Invalid start point.");
1214                         break;
1215                 case '?':
1216                 default:
1217                         usage();
1218                 }
1219         }
1220
1221         /* reinit */
1222         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1223
1224         if (optind < ac) {
1225                 printf("Too many arguments.\n");
1226                 usage();
1227         }
1228         if (change_passphrase && change_comment) {
1229                 printf("Can only have one of -p and -c.\n");
1230                 usage();
1231         }
1232         if (delete_host || hash_hosts || find_host)
1233                 do_known_hosts(pw, rr_hostname);
1234         if (print_fingerprint || print_bubblebabble)
1235                 do_fingerprint(pw);
1236         if (change_passphrase)
1237                 do_change_passphrase(pw);
1238         if (change_comment)
1239                 do_change_comment(pw);
1240         if (convert_to_ssh2)
1241                 do_convert_to_ssh2(pw);
1242         if (convert_from_ssh2)
1243                 do_convert_from_ssh2(pw);
1244         if (print_public)
1245                 do_print_public(pw);
1246         if (rr_hostname != NULL) {
1247                 unsigned int n = 0;
1248
1249                 if (have_identity) {
1250                         n = do_print_resource_record(pw,
1251                             identity_file, rr_hostname);
1252                         if (n == 0) {
1253                                 perror(identity_file);
1254                                 exit(1);
1255                         }
1256                         exit(0);
1257                 } else {
1258
1259                         n += do_print_resource_record(pw,
1260                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1261                         n += do_print_resource_record(pw,
1262                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1263
1264                         if (n == 0)
1265                                 fatal("no keys found.");
1266                         exit(0);
1267                 }
1268         }
1269         if (reader_id != NULL) {
1270 #ifdef SMARTCARD
1271                 if (download)
1272                         do_download(pw, reader_id);
1273                 else
1274                         do_upload(pw, reader_id);
1275 #else /* SMARTCARD */
1276                 fatal("no support for smartcards.");
1277 #endif /* SMARTCARD */
1278         }
1279
1280         if (do_gen_candidates) {
1281                 FILE *out = fopen(out_file, "w");
1282
1283                 if (out == NULL) {
1284                         error("Couldn't open modulus candidate file \"%s\": %s",
1285                             out_file, strerror(errno));
1286                         return (1);
1287                 }
1288                 if (bits == 0)
1289                         bits = DEFAULT_BITS;
1290                 if (gen_candidates(out, memory, bits, start) != 0)
1291                         fatal("modulus candidate generation failed");
1292
1293                 return (0);
1294         }
1295
1296         if (do_screen_candidates) {
1297                 FILE *in;
1298                 FILE *out = fopen(out_file, "w");
1299
1300                 if (have_identity && strcmp(identity_file, "-") != 0) {
1301                         if ((in = fopen(identity_file, "r")) == NULL) {
1302                                 fatal("Couldn't open modulus candidate "
1303                                     "file \"%s\": %s", identity_file,
1304                                     strerror(errno));
1305                         }
1306                 } else
1307                         in = stdin;
1308
1309                 if (out == NULL) {
1310                         fatal("Couldn't open moduli file \"%s\": %s",
1311                             out_file, strerror(errno));
1312                 }
1313                 if (prime_test(in, out, trials, generator_wanted) != 0)
1314                         fatal("modulus screening failed");
1315                 return (0);
1316         }
1317
1318         arc4random_stir();
1319
1320         if (key_type_name == NULL)
1321                 key_type_name = "rsa";
1322
1323         type = key_type_from_name(key_type_name);
1324         if (type == KEY_UNSPEC) {
1325                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1326                 exit(1);
1327         }
1328         if (bits == 0)
1329                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1330         if (type == KEY_DSA && bits != 1024)
1331                 fatal("DSA keys must be 1024 bits");
1332         if (!quiet)
1333                 printf("Generating public/private %s key pair.\n", key_type_name);
1334         private = key_generate(type, bits);
1335         if (private == NULL) {
1336                 fprintf(stderr, "key_generate failed");
1337                 exit(1);
1338         }
1339         public  = key_from_private(private);
1340
1341         if (!have_identity)
1342                 ask_filename(pw, "Enter file in which to save the key");
1343
1344         /* Create ~/.ssh directory if it doesn't already exist. */
1345         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1346         if (strstr(identity_file, dotsshdir) != NULL &&
1347             stat(dotsshdir, &st) < 0) {
1348                 if (mkdir(dotsshdir, 0700) < 0)
1349                         error("Could not create directory '%s'.", dotsshdir);
1350                 else if (!quiet)
1351                         printf("Created directory '%s'.\n", dotsshdir);
1352         }
1353         /* If the file already exists, ask the user to confirm. */
1354         if (stat(identity_file, &st) >= 0) {
1355                 char yesno[3];
1356                 printf("%s already exists.\n", identity_file);
1357                 printf("Overwrite (y/n)? ");
1358                 fflush(stdout);
1359                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1360                         exit(1);
1361                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1362                         exit(1);
1363         }
1364         /* Ask for a passphrase (twice). */
1365         if (identity_passphrase)
1366                 passphrase1 = xstrdup(identity_passphrase);
1367         else if (identity_new_passphrase)
1368                 passphrase1 = xstrdup(identity_new_passphrase);
1369         else {
1370 passphrase_again:
1371                 passphrase1 =
1372                         read_passphrase("Enter passphrase (empty for no "
1373                             "passphrase): ", RP_ALLOW_STDIN);
1374                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1375                     RP_ALLOW_STDIN);
1376                 if (strcmp(passphrase1, passphrase2) != 0) {
1377                         /*
1378                          * The passphrases do not match.  Clear them and
1379                          * retry.
1380                          */
1381                         memset(passphrase1, 0, strlen(passphrase1));
1382                         memset(passphrase2, 0, strlen(passphrase2));
1383                         xfree(passphrase1);
1384                         xfree(passphrase2);
1385                         printf("Passphrases do not match.  Try again.\n");
1386                         goto passphrase_again;
1387                 }
1388                 /* Clear the other copy of the passphrase. */
1389                 memset(passphrase2, 0, strlen(passphrase2));
1390                 xfree(passphrase2);
1391         }
1392
1393         if (identity_comment) {
1394                 strlcpy(comment, identity_comment, sizeof(comment));
1395         } else {
1396                 /* Create default commend field for the passphrase. */
1397                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1398         }
1399
1400         /* Save the key with the given passphrase and comment. */
1401         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1402                 printf("Saving the key failed: %s.\n", identity_file);
1403                 memset(passphrase1, 0, strlen(passphrase1));
1404                 xfree(passphrase1);
1405                 exit(1);
1406         }
1407         /* Clear the passphrase. */
1408         memset(passphrase1, 0, strlen(passphrase1));
1409         xfree(passphrase1);
1410
1411         /* Clear the private key and the random number generator. */
1412         key_free(private);
1413         arc4random_stir();
1414
1415         if (!quiet)
1416                 printf("Your identification has been saved in %s.\n", identity_file);
1417
1418         strlcat(identity_file, ".pub", sizeof(identity_file));
1419         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1420         if (fd == -1) {
1421                 printf("Could not save your public key in %s\n", identity_file);
1422                 exit(1);
1423         }
1424         f = fdopen(fd, "w");
1425         if (f == NULL) {
1426                 printf("fdopen %s failed", identity_file);
1427                 exit(1);
1428         }
1429         if (!key_write(public, f))
1430                 fprintf(stderr, "write key failed");
1431         fprintf(f, " %s\n", comment);
1432         fclose(f);
1433
1434         if (!quiet) {
1435                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1436                 printf("Your public key has been saved in %s.\n",
1437                     identity_file);
1438                 printf("The key fingerprint is:\n");
1439                 printf("%s %s\n", fp, comment);
1440                 xfree(fp);
1441         }
1442
1443         key_free(public);
1444         exit(0);
1445 }