ssh-keygen.c

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