ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.143 2006/03/30 11:05:17 dtucker 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/stat.h>
  19
  20 #include <openssl/evp.h>
  21 #include <openssl/pem.h>
  22
  23 #include "xmalloc.h"
  24 #include "key.h"
  25 #include "rsa.h"
  26 #include "authfile.h"
  27 #include "uuencode.h"
  28 #include "buffer.h"
  29 #include "bufaux.h"
  30 #include "pathnames.h"
  31 #include "log.h"
  32 #include "misc.h"
  33 #include "match.h"
  34 #include "hostfile.h"
  35
  36 #ifdef SMARTCARD
  37 #include "scard.h"
  38 #endif
  39 #include "dns.h"
  40
  41 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  42 #define DEFAULT_BITS            2048
  43 #define DEFAULT_BITS_DSA        1024
  44 u_int32_t bits = 0;
  45
  46 /*
  47  * Flag indicating that we just want to change the passphrase.  This can be
  48  * set on the command line.
  49  */
  50 int change_passphrase = 0;
  51
  52 /*
  53  * Flag indicating that we just want to change the comment.  This can be set
  54  * on the command line.
  55  */
  56 int change_comment = 0;
  57
  58 int quiet = 0;
  59
  60 /* Flag indicating that we want to hash a known_hosts file */
  61 int hash_hosts = 0;
  62 /* Flag indicating that we want lookup a host in known_hosts file */
  63 int find_host = 0;
  64 /* Flag indicating that we want to delete a host from a known_hosts file */
  65 int delete_host = 0;
  66
  67 /* Flag indicating that we just want to see the key fingerprint */
  68 int print_fingerprint = 0;
  69 int print_bubblebabble = 0;
  70
  71 /* The identity file name, given on the command line or entered by the user. */
  72 char identity_file[1024];
  73 int have_identity = 0;
  74
  75 /* This is set to the passphrase if given on the command line. */
  76 char *identity_passphrase = NULL;
  77
  78 /* This is set to the new passphrase if given on the command line. */
  79 char *identity_new_passphrase = NULL;
  80
  81 /* This is set to the new comment if given on the command line. */
  82 char *identity_comment = NULL;
  83
  84 /* Dump public key file in format used by real and the original SSH 2 */
  85 int convert_to_ssh2 = 0;
  86 int convert_from_ssh2 = 0;
  87 int print_public = 0;
  88 int print_generic = 0;
  89
  90 char *key_type_name = NULL;
  91
  92 /* argv0 */
  93 extern char *__progname;
  94
  95 char hostname[MAXHOSTNAMELEN];
  96
  97 /* moduli.c */
  98 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
  99 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 100
 101 static void
 102 ask_filename(struct passwd *pw, const char *prompt)
 103 {
 104         char buf[1024];
 105         char *name = NULL;
 106
 107         if (key_type_name == NULL)
 108                 name = _PATH_SSH_CLIENT_ID_RSA;
 109         else {
 110                 switch (key_type_from_name(key_type_name)) {
 111                 case KEY_RSA1:
 112                         name = _PATH_SSH_CLIENT_IDENTITY;
 113                         break;
 114                 case KEY_DSA:
 115                         name = _PATH_SSH_CLIENT_ID_DSA;
 116                         break;
 117                 case KEY_RSA:
 118                         name = _PATH_SSH_CLIENT_ID_RSA;
 119                         break;
 120                 default:
 121                         fprintf(stderr, "bad key type");
 122                         exit(1);
 123                         break;
 124                 }
 125         }
 126         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 127         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 128         if (fgets(buf, sizeof(buf), stdin) == NULL)
 129                 exit(1);
 130         if (strchr(buf, '\n'))
 131                 *strchr(buf, '\n') = 0;
 132         if (strcmp(buf, "") != 0)
 133                 strlcpy(identity_file, buf, sizeof(identity_file));
 134         have_identity = 1;
 135 }
 136
 137 static Key *
 138 load_identity(char *filename)
 139 {
 140         char *pass;
 141         Key *prv;
 142
 143         prv = key_load_private(filename, "", NULL);
 144         if (prv == NULL) {
 145                 if (identity_passphrase)
 146                         pass = xstrdup(identity_passphrase);
 147                 else
 148                         pass = read_passphrase("Enter passphrase: ",
 149                             RP_ALLOW_STDIN);
 150                 prv = key_load_private(filename, pass, NULL);
 151                 memset(pass, 0, strlen(pass));
 152                 xfree(pass);
 153         }
 154         return prv;
 155 }
 156
 157 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 158 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 159 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 160 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 161
 162 static void
 163 do_convert_to_ssh2(struct passwd *pw)
 164 {
 165         Key *k;
 166         u_int len;
 167         u_char *blob;
 168         struct stat st;
 169
 170         if (!have_identity)
 171                 ask_filename(pw, "Enter file in which the key is");
 172         if (stat(identity_file, &st) < 0) {
 173                 perror(identity_file);
 174                 exit(1);
 175         }
 176         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 177                 if ((k = load_identity(identity_file)) == NULL) {
 178                         fprintf(stderr, "load failed\n");
 179                         exit(1);
 180                 }
 181         }
 182         if (k->type == KEY_RSA1) {
 183                 fprintf(stderr, "version 1 keys are not supported\n");
 184                 exit(1);
 185         }
 186         if (key_to_blob(k, &blob, &len) <= 0) {
 187                 fprintf(stderr, "key_to_blob failed\n");
 188                 exit(1);
 189         }
 190         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 191         fprintf(stdout,
 192             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 193             key_size(k), key_type(k),
 194             pw->pw_name, hostname);
 195         dump_base64(stdout, blob, len);
 196         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 197         key_free(k);
 198         xfree(blob);
 199         exit(0);
 200 }
 201
 202 static void
 203 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 204 {
 205         u_int bignum_bits = buffer_get_int(b);
 206         u_int bytes = (bignum_bits + 7) / 8;
 207
 208         if (buffer_len(b) < bytes)
 209                 fatal("buffer_get_bignum_bits: input buffer too small: "
 210                     "need %d have %d", bytes, buffer_len(b));
 211         BN_bin2bn(buffer_ptr(b), bytes, value);
 212         buffer_consume(b, bytes);
 213 }
 214
 215 static Key *
 216 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 217 {
 218         Buffer b;
 219         Key *key = NULL;
 220         char *type, *cipher;
 221         u_char *sig, data[] = "abcde12345";
 222         int magic, rlen, ktype, i1, i2, i3, i4;
 223         u_int slen;
 224         u_long e;
 225
 226         buffer_init(&b);
 227         buffer_append(&b, blob, blen);
 228
 229         magic  = buffer_get_int(&b);
 230         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 231                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 232                 buffer_free(&b);
 233                 return NULL;
 234         }
 235         i1 = buffer_get_int(&b);
 236         type   = buffer_get_string(&b, NULL);
 237         cipher = buffer_get_string(&b, NULL);
 238         i2 = buffer_get_int(&b);
 239         i3 = buffer_get_int(&b);
 240         i4 = buffer_get_int(&b);
 241         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 242         if (strcmp(cipher, "none") != 0) {
 243                 error("unsupported cipher %s", cipher);
 244                 xfree(cipher);
 245                 buffer_free(&b);
 246                 xfree(type);
 247                 return NULL;
 248         }
 249         xfree(cipher);
 250
 251         if (strstr(type, "dsa")) {
 252                 ktype = KEY_DSA;
 253         } else if (strstr(type, "rsa")) {
 254                 ktype = KEY_RSA;
 255         } else {
 256                 buffer_free(&b);
 257                 xfree(type);
 258                 return NULL;
 259         }
 260         key = key_new_private(ktype);
 261         xfree(type);
 262
 263         switch (key->type) {
 264         case KEY_DSA:
 265                 buffer_get_bignum_bits(&b, key->dsa->p);
 266                 buffer_get_bignum_bits(&b, key->dsa->g);
 267                 buffer_get_bignum_bits(&b, key->dsa->q);
 268                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 269                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 270                 break;
 271         case KEY_RSA:
 272                 e  = buffer_get_char(&b);
 273                 debug("e %lx", e);
 274                 if (e < 30) {
 275                         e <<= 8;
 276                         e += buffer_get_char(&b);
 277                         debug("e %lx", e);
 278                         e <<= 8;
 279                         e += buffer_get_char(&b);
 280                         debug("e %lx", e);
 281                 }
 282                 if (!BN_set_word(key->rsa->e, e)) {
 283                         buffer_free(&b);
 284                         key_free(key);
 285                         return NULL;
 286                 }
 287                 buffer_get_bignum_bits(&b, key->rsa->d);
 288                 buffer_get_bignum_bits(&b, key->rsa->n);
 289                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 290                 buffer_get_bignum_bits(&b, key->rsa->q);
 291                 buffer_get_bignum_bits(&b, key->rsa->p);
 292                 rsa_generate_additional_parameters(key->rsa);
 293                 break;
 294         }
 295         rlen = buffer_len(&b);
 296         if (rlen != 0)
 297                 error("do_convert_private_ssh2_from_blob: "
 298                     "remaining bytes in key blob %d", rlen);
 299         buffer_free(&b);
 300
 301         /* try the key */
 302         key_sign(key, &sig, &slen, data, sizeof(data));
 303         key_verify(key, sig, slen, data, sizeof(data));
 304         xfree(sig);
 305         return key;
 306 }
 307
 308 static int
 309 get_line(FILE *fp, char *line, size_t len)
 310 {
 311         int c;
 312         size_t pos = 0;
 313
 314         line[0] = '\0';
 315         while ((c = fgetc(fp)) != EOF) {
 316                 if (pos >= len - 1) {
 317                         fprintf(stderr, "input line too long.\n");
 318                         exit(1);
 319                 }
 320                 switch (c) {
 321                 case '\r':
 322                         c = fgetc(fp);
 323                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 324                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 325                                 exit(1);
 326                         }
 327                         return pos;
 328                 case '\n':
 329                         return pos;
 330                 }
 331                 line[pos++] = c;
 332                 line[pos] = '\0';
 333         }
 334         if (c == EOF)
 335                 return -1;
 336         return pos;
 337 }
 338
 339 static void
 340 do_convert_from_ssh2(struct passwd *pw)
 341 {
 342         Key *k;
 343         int blen;
 344         u_int len;
 345         char line[1024];
 346         u_char blob[8096];
 347         char encoded[8096];
 348         struct stat st;
 349         int escaped = 0, private = 0, ok;
 350         FILE *fp;
 351
 352         if (!have_identity)
 353                 ask_filename(pw, "Enter file in which the key is");
 354         if (stat(identity_file, &st) < 0) {
 355                 perror(identity_file);
 356                 exit(1);
 357         }
 358         fp = fopen(identity_file, "r");
 359         if (fp == NULL) {
 360                 perror(identity_file);
 361                 exit(1);
 362         }
 363         encoded[0] = '\0';
 364         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 365                 if (line[blen - 1] == '\\')
 366                         escaped++;
 367                 if (strncmp(line, "----", 4) == 0 ||
 368                     strstr(line, ": ") != NULL) {
 369                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 370                                 private = 1;
 371                         if (strstr(line, " END ") != NULL) {
 372                                 break;
 373                         }
 374                         /* fprintf(stderr, "ignore: %s", line); */
 375                         continue;
 376                 }
 377                 if (escaped) {
 378                         escaped--;
 379                         /* fprintf(stderr, "escaped: %s", line); */
 380                         continue;
 381                 }
 382                 strlcat(encoded, line, sizeof(encoded));
 383         }
 384         len = strlen(encoded);
 385         if (((len % 4) == 3) &&
 386             (encoded[len-1] == '=') &&
 387             (encoded[len-2] == '=') &&
 388             (encoded[len-3] == '='))
 389                 encoded[len-3] = '\0';
 390         blen = uudecode(encoded, blob, sizeof(blob));
 391         if (blen < 0) {
 392                 fprintf(stderr, "uudecode failed.\n");
 393                 exit(1);
 394         }
 395         k = private ?
 396             do_convert_private_ssh2_from_blob(blob, blen) :
 397             key_from_blob(blob, blen);
 398         if (k == NULL) {
 399                 fprintf(stderr, "decode blob failed.\n");
 400                 exit(1);
 401         }
 402         ok = private ?
 403             (k->type == KEY_DSA ?
 404                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 405                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 406             key_write(k, stdout);
 407         if (!ok) {
 408                 fprintf(stderr, "key write failed");
 409                 exit(1);
 410         }
 411         key_free(k);
 412         if (!private)
 413                 fprintf(stdout, "\n");
 414         fclose(fp);
 415         exit(0);
 416 }
 417
 418 static void
 419 do_print_public(struct passwd *pw)
 420 {
 421         Key *prv;
 422         struct stat st;
 423
 424         if (!have_identity)
 425                 ask_filename(pw, "Enter file in which the key is");
 426         if (stat(identity_file, &st) < 0) {
 427                 perror(identity_file);
 428                 exit(1);
 429         }
 430         prv = load_identity(identity_file);
 431         if (prv == NULL) {
 432                 fprintf(stderr, "load failed\n");
 433                 exit(1);
 434         }
 435         if (!key_write(prv, stdout))
 436                 fprintf(stderr, "key_write failed");
 437         key_free(prv);
 438         fprintf(stdout, "\n");
 439         exit(0);
 440 }
 441
 442 #ifdef SMARTCARD
 443 static void
 444 do_upload(struct passwd *pw, const char *sc_reader_id)
 445 {
 446         Key *prv = NULL;
 447         struct stat st;
 448         int ret;
 449
 450         if (!have_identity)
 451                 ask_filename(pw, "Enter file in which the key is");
 452         if (stat(identity_file, &st) < 0) {
 453                 perror(identity_file);
 454                 exit(1);
 455         }
 456         prv = load_identity(identity_file);
 457         if (prv == NULL) {
 458                 error("load failed");
 459                 exit(1);
 460         }
 461         ret = sc_put_key(prv, sc_reader_id);
 462         key_free(prv);
 463         if (ret < 0)
 464                 exit(1);
 465         logit("loading key done");
 466         exit(0);
 467 }
 468
 469 static void
 470 do_download(struct passwd *pw, const char *sc_reader_id)
 471 {
 472         Key **keys = NULL;
 473         int i;
 474
 475         keys = sc_get_keys(sc_reader_id, NULL);
 476         if (keys == NULL)
 477                 fatal("cannot read public key from smartcard");
 478         for (i = 0; keys[i]; i++) {
 479                 key_write(keys[i], stdout);
 480                 key_free(keys[i]);
 481                 fprintf(stdout, "\n");
 482         }
 483         xfree(keys);
 484         exit(0);
 485 }
 486 #endif /* SMARTCARD */
 487
 488 static void
 489 do_fingerprint(struct passwd *pw)
 490 {
 491         FILE *f;
 492         Key *public;
 493         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 494         int i, skip = 0, num = 1, invalid = 1;
 495         enum fp_rep rep;
 496         enum fp_type fptype;
 497         struct stat st;
 498
 499         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 500         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 501
 502         if (!have_identity)
 503                 ask_filename(pw, "Enter file in which the key is");
 504         if (stat(identity_file, &st) < 0) {
 505                 perror(identity_file);
 506                 exit(1);
 507         }
 508         public = key_load_public(identity_file, &comment);
 509         if (public != NULL) {
 510                 fp = key_fingerprint(public, fptype, rep);
 511                 printf("%u %s %s\n", key_size(public), fp, comment);
 512                 key_free(public);
 513                 xfree(comment);
 514                 xfree(fp);
 515                 exit(0);
 516         }
 517         if (comment)
 518                 xfree(comment);
 519
 520         f = fopen(identity_file, "r");
 521         if (f != NULL) {
 522                 while (fgets(line, sizeof(line), f)) {
 523                         i = strlen(line) - 1;
 524                         if (line[i] != '\n') {
 525                                 error("line %d too long: %.40s...", num, line);
 526                                 skip = 1;
 527                                 continue;
 528                         }
 529                         num++;
 530                         if (skip) {
 531                                 skip = 0;
 532                                 continue;
 533                         }
 534                         line[i] = '\0';
 535
 536                         /* Skip leading whitespace, empty and comment lines. */
 537                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 538                                 ;
 539                         if (!*cp || *cp == '\n' || *cp == '#')
 540                                 continue ;
 541                         i = strtol(cp, &ep, 10);
 542                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 543                                 int quoted = 0;
 544                                 comment = cp;
 545                                 for (; *cp && (quoted || (*cp != ' ' &&
 546                                     *cp != '\t')); cp++) {
 547                                         if (*cp == '\\' && cp[1] == '"')
 548                                                 cp++;   /* Skip both */
 549                                         else if (*cp == '"')
 550                                                 quoted = !quoted;
 551                                 }
 552                                 if (!*cp)
 553                                         continue;
 554                                 *cp++ = '\0';
 555                         }
 556                         ep = cp;
 557                         public = key_new(KEY_RSA1);
 558                         if (key_read(public, &cp) != 1) {
 559                                 cp = ep;
 560                                 key_free(public);
 561                                 public = key_new(KEY_UNSPEC);
 562                                 if (key_read(public, &cp) != 1) {
 563                                         key_free(public);
 564                                         continue;
 565                                 }
 566                         }
 567                         comment = *cp ? cp : comment;
 568                         fp = key_fingerprint(public, fptype, rep);
 569                         printf("%u %s %s\n", key_size(public), fp,
 570                             comment ? comment : "no comment");
 571                         xfree(fp);
 572                         key_free(public);
 573                         invalid = 0;
 574                 }
 575                 fclose(f);
 576         }
 577         if (invalid) {
 578                 printf("%s is not a public key file.\n", identity_file);
 579                 exit(1);
 580         }
 581         exit(0);
 582 }
 583
 584 static void
 585 print_host(FILE *f, char *name, Key *public, int hash)
 586 {
 587         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 588                 fatal("hash_host failed");
 589         fprintf(f, "%s ", name);
 590         if (!key_write(public, f))
 591                 fatal("key_write failed");
 592         fprintf(f, "\n");
 593 }
 594
 595 static void
 596 do_known_hosts(struct passwd *pw, const char *name)
 597 {
 598         FILE *in, *out = stdout;
 599         Key *public;
 600         char *cp, *cp2, *kp, *kp2;
 601         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 602         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 603
 604         if (!have_identity) {
 605                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 606                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 607                     sizeof(identity_file))
 608                         fatal("Specified known hosts path too long");
 609                 xfree(cp);
 610                 have_identity = 1;
 611         }
 612         if ((in = fopen(identity_file, "r")) == NULL)
 613                 fatal("fopen: %s", strerror(errno));
 614
 615         /*
 616          * Find hosts goes to stdout, hash and deletions happen in-place
 617          * A corner case is ssh-keygen -HF foo, which should go to stdout
 618          */
 619         if (!find_host && (hash_hosts || delete_host)) {
 620                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 621                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 622                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 623                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 624                         fatal("known_hosts path too long");
 625                 umask(077);
 626                 if ((c = mkstemp(tmp)) == -1)
 627                         fatal("mkstemp: %s", strerror(errno));
 628                 if ((out = fdopen(c, "w")) == NULL) {
 629                         c = errno;
 630                         unlink(tmp);
 631                         fatal("fdopen: %s", strerror(c));
 632                 }
 633                 inplace = 1;
 634         }
 635
 636         while (fgets(line, sizeof(line), in)) {
 637                 num++;
 638                 i = strlen(line) - 1;
 639                 if (line[i] != '\n') {
 640                         error("line %d too long: %.40s...", num, line);
 641                         skip = 1;
 642                         invalid = 1;
 643                         continue;
 644                 }
 645                 if (skip) {
 646                         skip = 0;
 647                         continue;
 648                 }
 649                 line[i] = '\0';
 650
 651                 /* Skip leading whitespace, empty and comment lines. */
 652                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 653                         ;
 654                 if (!*cp || *cp == '\n' || *cp == '#') {
 655                         if (inplace)
 656                                 fprintf(out, "%s\n", cp);
 657                         continue;
 658                 }
 659                 /* Find the end of the host name portion. */
 660                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 661                         ;
 662                 if (*kp == '\0' || *(kp + 1) == '\0') {
 663                         error("line %d missing key: %.40s...",
 664                             num, line);
 665                         invalid = 1;
 666                         continue;
 667                 }
 668                 *kp++ = '\0';
 669                 kp2 = kp;
 670
 671                 public = key_new(KEY_RSA1);
 672                 if (key_read(public, &kp) != 1) {
 673                         kp = kp2;
 674                         key_free(public);
 675                         public = key_new(KEY_UNSPEC);
 676                         if (key_read(public, &kp) != 1) {
 677                                 error("line %d invalid key: %.40s...",
 678                                     num, line);
 679                                 key_free(public);
 680                                 invalid = 1;
 681                                 continue;
 682                         }
 683                 }
 684
 685                 if (*cp == HASH_DELIM) {
 686                         if (find_host || delete_host) {
 687                                 cp2 = host_hash(name, cp, strlen(cp));
 688                                 if (cp2 == NULL) {
 689                                         error("line %d: invalid hashed "
 690                                             "name: %.64s...", num, line);
 691                                         invalid = 1;
 692                                         continue;
 693                                 }
 694                                 c = (strcmp(cp2, cp) == 0);
 695                                 if (find_host && c) {
 696                                         printf("# Host %s found: "
 697                                             "line %d type %s\n", name,
 698                                             num, key_type(public));
 699                                         print_host(out, cp, public, 0);
 700                                 }
 701                                 if (delete_host && !c)
 702                                         print_host(out, cp, public, 0);
 703                         } else if (hash_hosts)
 704                                 print_host(out, cp, public, 0);
 705                 } else {
 706                         if (find_host || delete_host) {
 707                                 c = (match_hostname(name, cp,
 708                                     strlen(cp)) == 1);
 709                                 if (find_host && c) {
 710                                         printf("# Host %s found: "
 711                                             "line %d type %s\n", name,
 712                                             num, key_type(public));
 713                                         print_host(out, cp, public, hash_hosts);
 714                                 }
 715                                 if (delete_host && !c)
 716                                         print_host(out, cp, public, 0);
 717                         } else if (hash_hosts) {
 718                                 for (cp2 = strsep(&cp, ",");
 719                                     cp2 != NULL && *cp2 != '\0';
 720                                     cp2 = strsep(&cp, ",")) {
 721                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 722                                                 fprintf(stderr, "Warning: "
 723                                                     "ignoring host name with "
 724                                                     "metacharacters: %.64s\n",
 725                                                     cp2);
 726                                         else
 727                                                 print_host(out, cp2, public, 1);
 728                                 }
 729                                 has_unhashed = 1;
 730                         }
 731                 }
 732                 key_free(public);
 733         }
 734         fclose(in);
 735
 736         if (invalid) {
 737                 fprintf(stderr, "%s is not a valid known_host file.\n",
 738                     identity_file);
 739                 if (inplace) {
 740                         fprintf(stderr, "Not replacing existing known_hosts "
 741                             "file because of errors\n");
 742                         fclose(out);
 743                         unlink(tmp);
 744                 }
 745                 exit(1);
 746         }
 747
 748         if (inplace) {
 749                 fclose(out);
 750
 751                 /* Backup existing file */
 752                 if (unlink(old) == -1 && errno != ENOENT)
 753                         fatal("unlink %.100s: %s", old, strerror(errno));
 754                 if (link(identity_file, old) == -1)
 755                         fatal("link %.100s to %.100s: %s", identity_file, old,
 756                             strerror(errno));
 757                 /* Move new one into place */
 758                 if (rename(tmp, identity_file) == -1) {
 759                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 760                             strerror(errno));
 761                         unlink(tmp);
 762                         unlink(old);
 763                         exit(1);
 764                 }
 765
 766                 fprintf(stderr, "%s updated.\n", identity_file);
 767                 fprintf(stderr, "Original contents retained as %s\n", old);
 768                 if (has_unhashed) {
 769                         fprintf(stderr, "WARNING: %s contains unhashed "
 770                             "entries\n", old);
 771                         fprintf(stderr, "Delete this file to ensure privacy "
 772                             "of hostnames\n");
 773                 }
 774         }
 775
 776         exit(0);
 777 }
 778
 779 /*
 780  * Perform changing a passphrase.  The argument is the passwd structure
 781  * for the current user.
 782  */
 783 static void
 784 do_change_passphrase(struct passwd *pw)
 785 {
 786         char *comment;
 787         char *old_passphrase, *passphrase1, *passphrase2;
 788         struct stat st;
 789         Key *private;
 790
 791         if (!have_identity)
 792                 ask_filename(pw, "Enter file in which the key is");
 793         if (stat(identity_file, &st) < 0) {
 794                 perror(identity_file);
 795                 exit(1);
 796         }
 797         /* Try to load the file with empty passphrase. */
 798         private = key_load_private(identity_file, "", &comment);
 799         if (private == NULL) {
 800                 if (identity_passphrase)
 801                         old_passphrase = xstrdup(identity_passphrase);
 802                 else
 803                         old_passphrase =
 804                             read_passphrase("Enter old passphrase: ",
 805                             RP_ALLOW_STDIN);
 806                 private = key_load_private(identity_file, old_passphrase,
 807                     &comment);
 808                 memset(old_passphrase, 0, strlen(old_passphrase));
 809                 xfree(old_passphrase);
 810                 if (private == NULL) {
 811                         printf("Bad passphrase.\n");
 812                         exit(1);
 813                 }
 814         }
 815         printf("Key has comment '%s'\n", comment);
 816
 817         /* Ask the new passphrase (twice). */
 818         if (identity_new_passphrase) {
 819                 passphrase1 = xstrdup(identity_new_passphrase);
 820                 passphrase2 = NULL;
 821         } else {
 822                 passphrase1 =
 823                         read_passphrase("Enter new passphrase (empty for no "
 824                             "passphrase): ", RP_ALLOW_STDIN);
 825                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 826                     RP_ALLOW_STDIN);
 827
 828                 /* Verify that they are the same. */
 829                 if (strcmp(passphrase1, passphrase2) != 0) {
 830                         memset(passphrase1, 0, strlen(passphrase1));
 831                         memset(passphrase2, 0, strlen(passphrase2));
 832                         xfree(passphrase1);
 833                         xfree(passphrase2);
 834                         printf("Pass phrases do not match.  Try again.\n");
 835                         exit(1);
 836                 }
 837                 /* Destroy the other copy. */
 838                 memset(passphrase2, 0, strlen(passphrase2));
 839                 xfree(passphrase2);
 840         }
 841
 842         /* Save the file using the new passphrase. */
 843         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 844                 printf("Saving the key failed: %s.\n", identity_file);
 845                 memset(passphrase1, 0, strlen(passphrase1));
 846                 xfree(passphrase1);
 847                 key_free(private);
 848                 xfree(comment);
 849                 exit(1);
 850         }
 851         /* Destroy the passphrase and the copy of the key in memory. */
 852         memset(passphrase1, 0, strlen(passphrase1));
 853         xfree(passphrase1);
 854         key_free(private);               /* Destroys contents */
 855         xfree(comment);
 856
 857         printf("Your identification has been saved with the new passphrase.\n");
 858         exit(0);
 859 }
 860
 861 /*
 862  * Print the SSHFP RR.
 863  */
 864 static int
 865 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 866 {
 867         Key *public;
 868         char *comment = NULL;
 869         struct stat st;
 870
 871         if (fname == NULL)
 872                 ask_filename(pw, "Enter file in which the key is");
 873         if (stat(fname, &st) < 0) {
 874                 if (errno == ENOENT)
 875                         return 0;
 876                 perror(fname);
 877                 exit(1);
 878         }
 879         public = key_load_public(fname, &comment);
 880         if (public != NULL) {
 881                 export_dns_rr(hname, public, stdout, print_generic);
 882                 key_free(public);
 883                 xfree(comment);
 884                 return 1;
 885         }
 886         if (comment)
 887                 xfree(comment);
 888
 889         printf("failed to read v2 public key from %s.\n", fname);
 890         exit(1);
 891 }
 892
 893 /*
 894  * Change the comment of a private key file.
 895  */
 896 static void
 897 do_change_comment(struct passwd *pw)
 898 {
 899         char new_comment[1024], *comment, *passphrase;
 900         Key *private;
 901         Key *public;
 902         struct stat st;
 903         FILE *f;
 904         int fd;
 905
 906         if (!have_identity)
 907                 ask_filename(pw, "Enter file in which the key is");
 908         if (stat(identity_file, &st) < 0) {
 909                 perror(identity_file);
 910                 exit(1);
 911         }
 912         private = key_load_private(identity_file, "", &comment);
 913         if (private == NULL) {
 914                 if (identity_passphrase)
 915                         passphrase = xstrdup(identity_passphrase);
 916                 else if (identity_new_passphrase)
 917                         passphrase = xstrdup(identity_new_passphrase);
 918                 else
 919                         passphrase = read_passphrase("Enter passphrase: ",
 920                             RP_ALLOW_STDIN);
 921                 /* Try to load using the passphrase. */
 922                 private = key_load_private(identity_file, passphrase, &comment);
 923                 if (private == NULL) {
 924                         memset(passphrase, 0, strlen(passphrase));
 925                         xfree(passphrase);
 926                         printf("Bad passphrase.\n");
 927                         exit(1);
 928                 }
 929         } else {
 930                 passphrase = xstrdup("");
 931         }
 932         if (private->type != KEY_RSA1) {
 933                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 934                 key_free(private);
 935                 exit(1);
 936         }
 937         printf("Key now has comment '%s'\n", comment);
 938
 939         if (identity_comment) {
 940                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 941         } else {
 942                 printf("Enter new comment: ");
 943                 fflush(stdout);
 944                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 945                         memset(passphrase, 0, strlen(passphrase));
 946                         key_free(private);
 947                         exit(1);
 948                 }
 949                 if (strchr(new_comment, '\n'))
 950                         *strchr(new_comment, '\n') = 0;
 951         }
 952
 953         /* Save the file using the new passphrase. */
 954         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 955                 printf("Saving the key failed: %s.\n", identity_file);
 956                 memset(passphrase, 0, strlen(passphrase));
 957                 xfree(passphrase);
 958                 key_free(private);
 959                 xfree(comment);
 960                 exit(1);
 961         }
 962         memset(passphrase, 0, strlen(passphrase));
 963         xfree(passphrase);
 964         public = key_from_private(private);
 965         key_free(private);
 966
 967         strlcat(identity_file, ".pub", sizeof(identity_file));
 968         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 969         if (fd == -1) {
 970                 printf("Could not save your public key in %s\n", identity_file);
 971                 exit(1);
 972         }
 973         f = fdopen(fd, "w");
 974         if (f == NULL) {
 975                 printf("fdopen %s failed", identity_file);
 976                 exit(1);
 977         }
 978         if (!key_write(public, f))
 979                 fprintf(stderr, "write key failed");
 980         key_free(public);
 981         fprintf(f, " %s\n", new_comment);
 982         fclose(f);
 983
 984         xfree(comment);
 985
 986         printf("The comment in your key file has been changed.\n");
 987         exit(0);
 988 }
 989
 990 static void
 991 usage(void)
 992 {
 993         fprintf(stderr, "Usage: %s [options]\n", __progname);
 994         fprintf(stderr, "Options:\n");
 995         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
 996         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
 997         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
 998         fprintf(stderr, "  -C comment  Provide new comment.\n");
 999         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1000 #ifdef SMARTCARD
1001         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1002 #endif /* SMARTCARD */
1003         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1004         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1005         fprintf(stderr, "  -f filename Filename of the key file.\n");
1006         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1007         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1008         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1009         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1010         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1011         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1012         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1013         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1014         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1015         fprintf(stderr, "  -q          Quiet.\n");
1016         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1017         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1018         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1019         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1020         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1021 #ifdef SMARTCARD
1022         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1023 #endif /* SMARTCARD */
1024         fprintf(stderr, "  -v          Verbose.\n");
1025         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1026         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1027
1028         exit(1);
1029 }
1030
1031 /*
1032  * Main program for key management.
1033  */
1034 int
1035 main(int ac, char **av)
1036 {
1037         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1038         char out_file[MAXPATHLEN], *reader_id = NULL;
1039         char *rr_hostname = NULL;
1040         Key *private, *public;
1041         struct passwd *pw;
1042         struct stat st;
1043         int opt, type, fd, download = 0;
1044         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1045         int do_gen_candidates = 0, do_screen_candidates = 0;
1046         int log_level = SYSLOG_LEVEL_INFO;
1047         BIGNUM *start = NULL;
1048         FILE *f;
1049         const char *errstr;
1050
1051         extern int optind;
1052         extern char *optarg;
1053
1054         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1055         sanitise_stdfd();
1056
1057         __progname = ssh_get_progname(av[0]);
1058
1059         SSLeay_add_all_algorithms();
1060         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1061
1062         init_rng();
1063         seed_rng();
1064
1065         /* we need this for the home * directory.  */
1066         pw = getpwuid(getuid());
1067         if (!pw) {
1068                 printf("You don't exist, go away!\n");
1069                 exit(1);
1070         }
1071         if (gethostname(hostname, sizeof(hostname)) < 0) {
1072                 perror("gethostname");
1073                 exit(1);
1074         }
1075
1076         while ((opt = getopt(ac, av,
1077             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1078                 switch (opt) {
1079                 case 'b':
1080                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1081                         if (errstr)
1082                                 fatal("Bits has bad value %s (%s)",
1083                                         optarg, errstr);
1084                         break;
1085                 case 'F':
1086                         find_host = 1;
1087                         rr_hostname = optarg;
1088                         break;
1089                 case 'H':
1090                         hash_hosts = 1;
1091                         break;
1092                 case 'R':
1093                         delete_host = 1;
1094                         rr_hostname = optarg;
1095                         break;
1096                 case 'l':
1097                         print_fingerprint = 1;
1098                         break;
1099                 case 'B':
1100                         print_bubblebabble = 1;
1101                         break;
1102                 case 'p':
1103                         change_passphrase = 1;
1104                         break;
1105                 case 'c':
1106                         change_comment = 1;
1107                         break;
1108                 case 'f':
1109                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1110                             sizeof(identity_file))
1111                                 fatal("Identity filename too long");
1112                         have_identity = 1;
1113                         break;
1114                 case 'g':
1115                         print_generic = 1;
1116                         break;
1117                 case 'P':
1118                         identity_passphrase = optarg;
1119                         break;
1120                 case 'N':
1121                         identity_new_passphrase = optarg;
1122                         break;
1123                 case 'C':
1124                         identity_comment = optarg;
1125                         break;
1126                 case 'q':
1127                         quiet = 1;
1128                         break;
1129                 case 'e':
1130                 case 'x':
1131                         /* export key */
1132                         convert_to_ssh2 = 1;
1133                         break;
1134                 case 'i':
1135                 case 'X':
1136                         /* import key */
1137                         convert_from_ssh2 = 1;
1138                         break;
1139                 case 'y':
1140                         print_public = 1;
1141                         break;
1142                 case 'd':
1143                         key_type_name = "dsa";
1144                         break;
1145                 case 't':
1146                         key_type_name = optarg;
1147                         break;
1148                 case 'D':
1149                         download = 1;
1150                         /*FALLTHROUGH*/
1151                 case 'U':
1152                         reader_id = optarg;
1153                         break;
1154                 case 'v':
1155                         if (log_level == SYSLOG_LEVEL_INFO)
1156                                 log_level = SYSLOG_LEVEL_DEBUG1;
1157                         else {
1158                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1159                                     log_level < SYSLOG_LEVEL_DEBUG3)
1160                                         log_level++;
1161                         }
1162                         break;
1163                 case 'r':
1164                         rr_hostname = optarg;
1165                         break;
1166                 case 'W':
1167                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1168                             UINT_MAX, &errstr);
1169                         if (errstr)
1170                                 fatal("Desired generator has bad value: %s (%s)",
1171                                         optarg, errstr);
1172                         break;
1173                 case 'a':
1174                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1175                         if (errstr)
1176                                 fatal("Invalid number of trials: %s (%s)",
1177                                         optarg, errstr);
1178                         break;
1179                 case 'M':
1180                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1181                         if (errstr) {
1182                                 fatal("Memory limit is %s: %s", errstr, optarg);
1183                         }
1184                         break;
1185                 case 'G':
1186                         do_gen_candidates = 1;
1187                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1188                             sizeof(out_file))
1189                                 fatal("Output filename too long");
1190                         break;
1191                 case 'T':
1192                         do_screen_candidates = 1;
1193                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1194                             sizeof(out_file))
1195                                 fatal("Output filename too long");
1196                         break;
1197                 case 'S':
1198                         /* XXX - also compare length against bits */
1199                         if (BN_hex2bn(&start, optarg) == 0)
1200                                 fatal("Invalid start point.");
1201                         break;
1202                 case '?':
1203                 default:
1204                         usage();
1205                 }
1206         }
1207
1208         /* reinit */
1209         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1210
1211         if (optind < ac) {
1212                 printf("Too many arguments.\n");
1213                 usage();
1214         }
1215         if (change_passphrase && change_comment) {
1216                 printf("Can only have one of -p and -c.\n");
1217                 usage();
1218         }
1219         if (delete_host || hash_hosts || find_host)
1220                 do_known_hosts(pw, rr_hostname);
1221         if (print_fingerprint || print_bubblebabble)
1222                 do_fingerprint(pw);
1223         if (change_passphrase)
1224                 do_change_passphrase(pw);
1225         if (change_comment)
1226                 do_change_comment(pw);
1227         if (convert_to_ssh2)
1228                 do_convert_to_ssh2(pw);
1229         if (convert_from_ssh2)
1230                 do_convert_from_ssh2(pw);
1231         if (print_public)
1232                 do_print_public(pw);
1233         if (rr_hostname != NULL) {
1234                 unsigned int n = 0;
1235
1236                 if (have_identity) {
1237                         n = do_print_resource_record(pw,
1238                             identity_file, rr_hostname);
1239                         if (n == 0) {
1240                                 perror(identity_file);
1241                                 exit(1);
1242                         }
1243                         exit(0);
1244                 } else {
1245
1246                         n += do_print_resource_record(pw,
1247                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1248                         n += do_print_resource_record(pw,
1249                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1250
1251                         if (n == 0)
1252                                 fatal("no keys found.");
1253                         exit(0);
1254                 }
1255         }
1256         if (reader_id != NULL) {
1257 #ifdef SMARTCARD
1258                 if (download)
1259                         do_download(pw, reader_id);
1260                 else
1261                         do_upload(pw, reader_id);
1262 #else /* SMARTCARD */
1263                 fatal("no support for smartcards.");
1264 #endif /* SMARTCARD */
1265         }
1266
1267         if (do_gen_candidates) {
1268                 FILE *out = fopen(out_file, "w");
1269
1270                 if (out == NULL) {
1271                         error("Couldn't open modulus candidate file \"%s\": %s",
1272                             out_file, strerror(errno));
1273                         return (1);
1274                 }
1275                 if (bits == 0)
1276                         bits = DEFAULT_BITS;
1277                 if (gen_candidates(out, memory, bits, start) != 0)
1278                         fatal("modulus candidate generation failed");
1279
1280                 return (0);
1281         }
1282
1283         if (do_screen_candidates) {
1284                 FILE *in;
1285                 FILE *out = fopen(out_file, "w");
1286
1287                 if (have_identity && strcmp(identity_file, "-") != 0) {
1288                         if ((in = fopen(identity_file, "r")) == NULL) {
1289                                 fatal("Couldn't open modulus candidate "
1290                                     "file \"%s\": %s", identity_file,
1291                                     strerror(errno));
1292                         }
1293                 } else
1294                         in = stdin;
1295
1296                 if (out == NULL) {
1297                         fatal("Couldn't open moduli file \"%s\": %s",
1298                             out_file, strerror(errno));
1299                 }
1300                 if (prime_test(in, out, trials, generator_wanted) != 0)
1301                         fatal("modulus screening failed");
1302                 return (0);
1303         }
1304
1305         arc4random_stir();
1306
1307         if (key_type_name == NULL)
1308                 key_type_name = "rsa";
1309
1310         type = key_type_from_name(key_type_name);
1311         if (type == KEY_UNSPEC) {
1312                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1313                 exit(1);
1314         }
1315         if (bits == 0)
1316                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1317         if (type == KEY_DSA && bits != 1024)
1318                 fatal("DSA keys must be 1024 bits");
1319         if (!quiet)
1320                 printf("Generating public/private %s key pair.\n", key_type_name);
1321         private = key_generate(type, bits);
1322         if (private == NULL) {
1323                 fprintf(stderr, "key_generate failed");
1324                 exit(1);
1325         }
1326         public  = key_from_private(private);
1327
1328         if (!have_identity)
1329                 ask_filename(pw, "Enter file in which to save the key");
1330
1331         /* Create ~/.ssh directory if it doesn't already exist. */
1332         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1333         if (strstr(identity_file, dotsshdir) != NULL &&
1334             stat(dotsshdir, &st) < 0) {
1335                 if (mkdir(dotsshdir, 0700) < 0)
1336                         error("Could not create directory '%s'.", dotsshdir);
1337                 else if (!quiet)
1338                         printf("Created directory '%s'.\n", dotsshdir);
1339         }
1340         /* If the file already exists, ask the user to confirm. */
1341         if (stat(identity_file, &st) >= 0) {
1342                 char yesno[3];
1343                 printf("%s already exists.\n", identity_file);
1344                 printf("Overwrite (y/n)? ");
1345                 fflush(stdout);
1346                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1347                         exit(1);
1348                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1349                         exit(1);
1350         }
1351         /* Ask for a passphrase (twice). */
1352         if (identity_passphrase)
1353                 passphrase1 = xstrdup(identity_passphrase);
1354         else if (identity_new_passphrase)
1355                 passphrase1 = xstrdup(identity_new_passphrase);
1356         else {
1357 passphrase_again:
1358                 passphrase1 =
1359                         read_passphrase("Enter passphrase (empty for no "
1360                             "passphrase): ", RP_ALLOW_STDIN);
1361                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1362                     RP_ALLOW_STDIN);
1363                 if (strcmp(passphrase1, passphrase2) != 0) {
1364                         /*
1365                          * The passphrases do not match.  Clear them and
1366                          * retry.
1367                          */
1368                         memset(passphrase1, 0, strlen(passphrase1));
1369                         memset(passphrase2, 0, strlen(passphrase2));
1370                         xfree(passphrase1);
1371                         xfree(passphrase2);
1372                         printf("Passphrases do not match.  Try again.\n");
1373                         goto passphrase_again;
1374                 }
1375                 /* Clear the other copy of the passphrase. */
1376                 memset(passphrase2, 0, strlen(passphrase2));
1377                 xfree(passphrase2);
1378         }
1379
1380         if (identity_comment) {
1381                 strlcpy(comment, identity_comment, sizeof(comment));
1382         } else {
1383                 /* Create default commend field for the passphrase. */
1384                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1385         }
1386
1387         /* Save the key with the given passphrase and comment. */
1388         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1389                 printf("Saving the key failed: %s.\n", identity_file);
1390                 memset(passphrase1, 0, strlen(passphrase1));
1391                 xfree(passphrase1);
1392                 exit(1);
1393         }
1394         /* Clear the passphrase. */
1395         memset(passphrase1, 0, strlen(passphrase1));
1396         xfree(passphrase1);
1397
1398         /* Clear the private key and the random number generator. */
1399         key_free(private);
1400         arc4random_stir();
1401
1402         if (!quiet)
1403                 printf("Your identification has been saved in %s.\n", identity_file);
1404
1405         strlcat(identity_file, ".pub", sizeof(identity_file));
1406         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1407         if (fd == -1) {
1408                 printf("Could not save your public key in %s\n", identity_file);
1409                 exit(1);
1410         }
1411         f = fdopen(fd, "w");
1412         if (f == NULL) {
1413                 printf("fdopen %s failed", identity_file);
1414                 exit(1);
1415         }
1416         if (!key_write(public, f))
1417                 fprintf(stderr, "write key failed");
1418         fprintf(f, " %s\n", comment);
1419         fclose(f);
1420
1421         if (!quiet) {
1422                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1423                 printf("Your public key has been saved in %s.\n",
1424                     identity_file);
1425                 printf("The key fingerprint is:\n");
1426                 printf("%s %s\n", fp, comment);
1427                 xfree(fp);
1428         }
1429
1430         key_free(public);
1431         exit(0);
1432 }