ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.146 2006/07/06 16:22:39 stevesk Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Identity and host key generation and maintenance.
   7  *
   8  * As far as I am concerned, the code I have written for this software
   9  * can be used freely for any purpose.  Any derived versions of this
  10  * software must be clearly marked as such, and if the derived work is
  11  * incompatible with the protocol description in the RFC file, it must be
  12  * called by a name other than "ssh" or "Secure Shell".
  13  */
  14
  15 #include "includes.h"
  16
  17 #include <sys/types.h>
  18 #include <sys/socket.h>
  19 #include <sys/stat.h>
  20
  21 #include <openssl/evp.h>
  22 #include <openssl/pem.h>
  23
  24 #include <paths.h>
  25 #include <pwd.h>
  26
  27 #include "xmalloc.h"
  28 #include "key.h"
  29 #include "rsa.h"
  30 #include "authfile.h"
  31 #include "uuencode.h"
  32 #include "buffer.h"
  33 #include "bufaux.h"
  34 #include "pathnames.h"
  35 #include "log.h"
  36 #include "misc.h"
  37 #include "match.h"
  38 #include "hostfile.h"
  39 #include "dns.h"
  40
  41 #ifdef SMARTCARD
  42 #include "scard.h"
  43 #endif
  44
  45 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  46 #define DEFAULT_BITS            2048
  47 #define DEFAULT_BITS_DSA        1024
  48 u_int32_t bits = 0;
  49
  50 /*
  51  * Flag indicating that we just want to change the passphrase.  This can be
  52  * set on the command line.
  53  */
  54 int change_passphrase = 0;
  55
  56 /*
  57  * Flag indicating that we just want to change the comment.  This can be set
  58  * on the command line.
  59  */
  60 int change_comment = 0;
  61
  62 int quiet = 0;
  63
  64 /* Flag indicating that we want to hash a known_hosts file */
  65 int hash_hosts = 0;
  66 /* Flag indicating that we want lookup a host in known_hosts file */
  67 int find_host = 0;
  68 /* Flag indicating that we want to delete a host from a known_hosts file */
  69 int delete_host = 0;
  70
  71 /* Flag indicating that we just want to see the key fingerprint */
  72 int print_fingerprint = 0;
  73 int print_bubblebabble = 0;
  74
  75 /* The identity file name, given on the command line or entered by the user. */
  76 char identity_file[1024];
  77 int have_identity = 0;
  78
  79 /* This is set to the passphrase if given on the command line. */
  80 char *identity_passphrase = NULL;
  81
  82 /* This is set to the new passphrase if given on the command line. */
  83 char *identity_new_passphrase = NULL;
  84
  85 /* This is set to the new comment if given on the command line. */
  86 char *identity_comment = NULL;
  87
  88 /* Dump public key file in format used by real and the original SSH 2 */
  89 int convert_to_ssh2 = 0;
  90 int convert_from_ssh2 = 0;
  91 int print_public = 0;
  92 int print_generic = 0;
  93
  94 char *key_type_name = NULL;
  95
  96 /* argv0 */
  97 extern char *__progname;
  98
  99 char hostname[MAXHOSTNAMELEN];
 100
 101 /* moduli.c */
 102 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 103 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 104
 105 static void
 106 ask_filename(struct passwd *pw, const char *prompt)
 107 {
 108         char buf[1024];
 109         char *name = NULL;
 110
 111         if (key_type_name == NULL)
 112                 name = _PATH_SSH_CLIENT_ID_RSA;
 113         else {
 114                 switch (key_type_from_name(key_type_name)) {
 115                 case KEY_RSA1:
 116                         name = _PATH_SSH_CLIENT_IDENTITY;
 117                         break;
 118                 case KEY_DSA:
 119                         name = _PATH_SSH_CLIENT_ID_DSA;
 120                         break;
 121                 case KEY_RSA:
 122                         name = _PATH_SSH_CLIENT_ID_RSA;
 123                         break;
 124                 default:
 125                         fprintf(stderr, "bad key type");
 126                         exit(1);
 127                         break;
 128                 }
 129         }
 130         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 131         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 132         if (fgets(buf, sizeof(buf), stdin) == NULL)
 133                 exit(1);
 134         if (strchr(buf, '\n'))
 135                 *strchr(buf, '\n') = 0;
 136         if (strcmp(buf, "") != 0)
 137                 strlcpy(identity_file, buf, sizeof(identity_file));
 138         have_identity = 1;
 139 }
 140
 141 static Key *
 142 load_identity(char *filename)
 143 {
 144         char *pass;
 145         Key *prv;
 146
 147         prv = key_load_private(filename, "", NULL);
 148         if (prv == NULL) {
 149                 if (identity_passphrase)
 150                         pass = xstrdup(identity_passphrase);
 151                 else
 152                         pass = read_passphrase("Enter passphrase: ",
 153                             RP_ALLOW_STDIN);
 154                 prv = key_load_private(filename, pass, NULL);
 155                 memset(pass, 0, strlen(pass));
 156                 xfree(pass);
 157         }
 158         return prv;
 159 }
 160
 161 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 162 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 163 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 164 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 165
 166 static void
 167 do_convert_to_ssh2(struct passwd *pw)
 168 {
 169         Key *k;
 170         u_int len;
 171         u_char *blob;
 172         struct stat st;
 173
 174         if (!have_identity)
 175                 ask_filename(pw, "Enter file in which the key is");
 176         if (stat(identity_file, &st) < 0) {
 177                 perror(identity_file);
 178                 exit(1);
 179         }
 180         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 181                 if ((k = load_identity(identity_file)) == NULL) {
 182                         fprintf(stderr, "load failed\n");
 183                         exit(1);
 184                 }
 185         }
 186         if (k->type == KEY_RSA1) {
 187                 fprintf(stderr, "version 1 keys are not supported\n");
 188                 exit(1);
 189         }
 190         if (key_to_blob(k, &blob, &len) <= 0) {
 191                 fprintf(stderr, "key_to_blob failed\n");
 192                 exit(1);
 193         }
 194         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 195         fprintf(stdout,
 196             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 197             key_size(k), key_type(k),
 198             pw->pw_name, hostname);
 199         dump_base64(stdout, blob, len);
 200         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 201         key_free(k);
 202         xfree(blob);
 203         exit(0);
 204 }
 205
 206 static void
 207 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 208 {
 209         u_int bignum_bits = buffer_get_int(b);
 210         u_int bytes = (bignum_bits + 7) / 8;
 211
 212         if (buffer_len(b) < bytes)
 213                 fatal("buffer_get_bignum_bits: input buffer too small: "
 214                     "need %d have %d", bytes, buffer_len(b));
 215         BN_bin2bn(buffer_ptr(b), bytes, value);
 216         buffer_consume(b, bytes);
 217 }
 218
 219 static Key *
 220 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 221 {
 222         Buffer b;
 223         Key *key = NULL;
 224         char *type, *cipher;
 225         u_char *sig, data[] = "abcde12345";
 226         int magic, rlen, ktype, i1, i2, i3, i4;
 227         u_int slen;
 228         u_long e;
 229
 230         buffer_init(&b);
 231         buffer_append(&b, blob, blen);
 232
 233         magic  = buffer_get_int(&b);
 234         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 235                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 236                 buffer_free(&b);
 237                 return NULL;
 238         }
 239         i1 = buffer_get_int(&b);
 240         type   = buffer_get_string(&b, NULL);
 241         cipher = buffer_get_string(&b, NULL);
 242         i2 = buffer_get_int(&b);
 243         i3 = buffer_get_int(&b);
 244         i4 = buffer_get_int(&b);
 245         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 246         if (strcmp(cipher, "none") != 0) {
 247                 error("unsupported cipher %s", cipher);
 248                 xfree(cipher);
 249                 buffer_free(&b);
 250                 xfree(type);
 251                 return NULL;
 252         }
 253         xfree(cipher);
 254
 255         if (strstr(type, "dsa")) {
 256                 ktype = KEY_DSA;
 257         } else if (strstr(type, "rsa")) {
 258                 ktype = KEY_RSA;
 259         } else {
 260                 buffer_free(&b);
 261                 xfree(type);
 262                 return NULL;
 263         }
 264         key = key_new_private(ktype);
 265         xfree(type);
 266
 267         switch (key->type) {
 268         case KEY_DSA:
 269                 buffer_get_bignum_bits(&b, key->dsa->p);
 270                 buffer_get_bignum_bits(&b, key->dsa->g);
 271                 buffer_get_bignum_bits(&b, key->dsa->q);
 272                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 273                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 274                 break;
 275         case KEY_RSA:
 276                 e  = buffer_get_char(&b);
 277                 debug("e %lx", e);
 278                 if (e < 30) {
 279                         e <<= 8;
 280                         e += buffer_get_char(&b);
 281                         debug("e %lx", e);
 282                         e <<= 8;
 283                         e += buffer_get_char(&b);
 284                         debug("e %lx", e);
 285                 }
 286                 if (!BN_set_word(key->rsa->e, e)) {
 287                         buffer_free(&b);
 288                         key_free(key);
 289                         return NULL;
 290                 }
 291                 buffer_get_bignum_bits(&b, key->rsa->d);
 292                 buffer_get_bignum_bits(&b, key->rsa->n);
 293                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 294                 buffer_get_bignum_bits(&b, key->rsa->q);
 295                 buffer_get_bignum_bits(&b, key->rsa->p);
 296                 rsa_generate_additional_parameters(key->rsa);
 297                 break;
 298         }
 299         rlen = buffer_len(&b);
 300         if (rlen != 0)
 301                 error("do_convert_private_ssh2_from_blob: "
 302                     "remaining bytes in key blob %d", rlen);
 303         buffer_free(&b);
 304
 305         /* try the key */
 306         key_sign(key, &sig, &slen, data, sizeof(data));
 307         key_verify(key, sig, slen, data, sizeof(data));
 308         xfree(sig);
 309         return key;
 310 }
 311
 312 static int
 313 get_line(FILE *fp, char *line, size_t len)
 314 {
 315         int c;
 316         size_t pos = 0;
 317
 318         line[0] = '\0';
 319         while ((c = fgetc(fp)) != EOF) {
 320                 if (pos >= len - 1) {
 321                         fprintf(stderr, "input line too long.\n");
 322                         exit(1);
 323                 }
 324                 switch (c) {
 325                 case '\r':
 326                         c = fgetc(fp);
 327                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 328                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 329                                 exit(1);
 330                         }
 331                         return pos;
 332                 case '\n':
 333                         return pos;
 334                 }
 335                 line[pos++] = c;
 336                 line[pos] = '\0';
 337         }
 338         if (c == EOF)
 339                 return -1;
 340         return pos;
 341 }
 342
 343 static void
 344 do_convert_from_ssh2(struct passwd *pw)
 345 {
 346         Key *k;
 347         int blen;
 348         u_int len;
 349         char line[1024];
 350         u_char blob[8096];
 351         char encoded[8096];
 352         struct stat st;
 353         int escaped = 0, private = 0, ok;
 354         FILE *fp;
 355
 356         if (!have_identity)
 357                 ask_filename(pw, "Enter file in which the key is");
 358         if (stat(identity_file, &st) < 0) {
 359                 perror(identity_file);
 360                 exit(1);
 361         }
 362         fp = fopen(identity_file, "r");
 363         if (fp == NULL) {
 364                 perror(identity_file);
 365                 exit(1);
 366         }
 367         encoded[0] = '\0';
 368         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 369                 if (line[blen - 1] == '\\')
 370                         escaped++;
 371                 if (strncmp(line, "----", 4) == 0 ||
 372                     strstr(line, ": ") != NULL) {
 373                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 374                                 private = 1;
 375                         if (strstr(line, " END ") != NULL) {
 376                                 break;
 377                         }
 378                         /* fprintf(stderr, "ignore: %s", line); */
 379                         continue;
 380                 }
 381                 if (escaped) {
 382                         escaped--;
 383                         /* fprintf(stderr, "escaped: %s", line); */
 384                         continue;
 385                 }
 386                 strlcat(encoded, line, sizeof(encoded));
 387         }
 388         len = strlen(encoded);
 389         if (((len % 4) == 3) &&
 390             (encoded[len-1] == '=') &&
 391             (encoded[len-2] == '=') &&
 392             (encoded[len-3] == '='))
 393                 encoded[len-3] = '\0';
 394         blen = uudecode(encoded, blob, sizeof(blob));
 395         if (blen < 0) {
 396                 fprintf(stderr, "uudecode failed.\n");
 397                 exit(1);
 398         }
 399         k = private ?
 400             do_convert_private_ssh2_from_blob(blob, blen) :
 401             key_from_blob(blob, blen);
 402         if (k == NULL) {
 403                 fprintf(stderr, "decode blob failed.\n");
 404                 exit(1);
 405         }
 406         ok = private ?
 407             (k->type == KEY_DSA ?
 408                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 409                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 410             key_write(k, stdout);
 411         if (!ok) {
 412                 fprintf(stderr, "key write failed");
 413                 exit(1);
 414         }
 415         key_free(k);
 416         if (!private)
 417                 fprintf(stdout, "\n");
 418         fclose(fp);
 419         exit(0);
 420 }
 421
 422 static void
 423 do_print_public(struct passwd *pw)
 424 {
 425         Key *prv;
 426         struct stat st;
 427
 428         if (!have_identity)
 429                 ask_filename(pw, "Enter file in which the key is");
 430         if (stat(identity_file, &st) < 0) {
 431                 perror(identity_file);
 432                 exit(1);
 433         }
 434         prv = load_identity(identity_file);
 435         if (prv == NULL) {
 436                 fprintf(stderr, "load failed\n");
 437                 exit(1);
 438         }
 439         if (!key_write(prv, stdout))
 440                 fprintf(stderr, "key_write failed");
 441         key_free(prv);
 442         fprintf(stdout, "\n");
 443         exit(0);
 444 }
 445
 446 #ifdef SMARTCARD
 447 static void
 448 do_upload(struct passwd *pw, const char *sc_reader_id)
 449 {
 450         Key *prv = NULL;
 451         struct stat st;
 452         int ret;
 453
 454         if (!have_identity)
 455                 ask_filename(pw, "Enter file in which the key is");
 456         if (stat(identity_file, &st) < 0) {
 457                 perror(identity_file);
 458                 exit(1);
 459         }
 460         prv = load_identity(identity_file);
 461         if (prv == NULL) {
 462                 error("load failed");
 463                 exit(1);
 464         }
 465         ret = sc_put_key(prv, sc_reader_id);
 466         key_free(prv);
 467         if (ret < 0)
 468                 exit(1);
 469         logit("loading key done");
 470         exit(0);
 471 }
 472
 473 static void
 474 do_download(struct passwd *pw, const char *sc_reader_id)
 475 {
 476         Key **keys = NULL;
 477         int i;
 478
 479         keys = sc_get_keys(sc_reader_id, NULL);
 480         if (keys == NULL)
 481                 fatal("cannot read public key from smartcard");
 482         for (i = 0; keys[i]; i++) {
 483                 key_write(keys[i], stdout);
 484                 key_free(keys[i]);
 485                 fprintf(stdout, "\n");
 486         }
 487         xfree(keys);
 488         exit(0);
 489 }
 490 #endif /* SMARTCARD */
 491
 492 static void
 493 do_fingerprint(struct passwd *pw)
 494 {
 495         FILE *f;
 496         Key *public;
 497         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 498         int i, skip = 0, num = 1, invalid = 1;
 499         enum fp_rep rep;
 500         enum fp_type fptype;
 501         struct stat st;
 502
 503         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 504         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 505
 506         if (!have_identity)
 507                 ask_filename(pw, "Enter file in which the key is");
 508         if (stat(identity_file, &st) < 0) {
 509                 perror(identity_file);
 510                 exit(1);
 511         }
 512         public = key_load_public(identity_file, &comment);
 513         if (public != NULL) {
 514                 fp = key_fingerprint(public, fptype, rep);
 515                 printf("%u %s %s\n", key_size(public), fp, comment);
 516                 key_free(public);
 517                 xfree(comment);
 518                 xfree(fp);
 519                 exit(0);
 520         }
 521         if (comment) {
 522                 xfree(comment);
 523                 comment = NULL;
 524         }
 525
 526         f = fopen(identity_file, "r");
 527         if (f != NULL) {
 528                 while (fgets(line, sizeof(line), f)) {
 529                         i = strlen(line) - 1;
 530                         if (line[i] != '\n') {
 531                                 error("line %d too long: %.40s...", num, line);
 532                                 skip = 1;
 533                                 continue;
 534                         }
 535                         num++;
 536                         if (skip) {
 537                                 skip = 0;
 538                                 continue;
 539                         }
 540                         line[i] = '\0';
 541
 542                         /* Skip leading whitespace, empty and comment lines. */
 543                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 544                                 ;
 545                         if (!*cp || *cp == '\n' || *cp == '#')
 546                                 continue ;
 547                         i = strtol(cp, &ep, 10);
 548                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 549                                 int quoted = 0;
 550                                 comment = cp;
 551                                 for (; *cp && (quoted || (*cp != ' ' &&
 552                                     *cp != '\t')); cp++) {
 553                                         if (*cp == '\\' && cp[1] == '"')
 554                                                 cp++;   /* Skip both */
 555                                         else if (*cp == '"')
 556                                                 quoted = !quoted;
 557                                 }
 558                                 if (!*cp)
 559                                         continue;
 560                                 *cp++ = '\0';
 561                         }
 562                         ep = cp;
 563                         public = key_new(KEY_RSA1);
 564                         if (key_read(public, &cp) != 1) {
 565                                 cp = ep;
 566                                 key_free(public);
 567                                 public = key_new(KEY_UNSPEC);
 568                                 if (key_read(public, &cp) != 1) {
 569                                         key_free(public);
 570                                         continue;
 571                                 }
 572                         }
 573                         comment = *cp ? cp : comment;
 574                         fp = key_fingerprint(public, fptype, rep);
 575                         printf("%u %s %s\n", key_size(public), fp,
 576                             comment ? comment : "no comment");
 577                         xfree(fp);
 578                         key_free(public);
 579                         invalid = 0;
 580                 }
 581                 fclose(f);
 582         }
 583         if (invalid) {
 584                 printf("%s is not a public key file.\n", identity_file);
 585                 exit(1);
 586         }
 587         exit(0);
 588 }
 589
 590 static void
 591 print_host(FILE *f, char *name, Key *public, int hash)
 592 {
 593         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 594                 fatal("hash_host failed");
 595         fprintf(f, "%s ", name);
 596         if (!key_write(public, f))
 597                 fatal("key_write failed");
 598         fprintf(f, "\n");
 599 }
 600
 601 static void
 602 do_known_hosts(struct passwd *pw, const char *name)
 603 {
 604         FILE *in, *out = stdout;
 605         Key *public;
 606         char *cp, *cp2, *kp, *kp2;
 607         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 608         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 609
 610         if (!have_identity) {
 611                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 612                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 613                     sizeof(identity_file))
 614                         fatal("Specified known hosts path too long");
 615                 xfree(cp);
 616                 have_identity = 1;
 617         }
 618         if ((in = fopen(identity_file, "r")) == NULL)
 619                 fatal("fopen: %s", strerror(errno));
 620
 621         /*
 622          * Find hosts goes to stdout, hash and deletions happen in-place
 623          * A corner case is ssh-keygen -HF foo, which should go to stdout
 624          */
 625         if (!find_host && (hash_hosts || delete_host)) {
 626                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 627                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 628                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 629                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 630                         fatal("known_hosts path too long");
 631                 umask(077);
 632                 if ((c = mkstemp(tmp)) == -1)
 633                         fatal("mkstemp: %s", strerror(errno));
 634                 if ((out = fdopen(c, "w")) == NULL) {
 635                         c = errno;
 636                         unlink(tmp);
 637                         fatal("fdopen: %s", strerror(c));
 638                 }
 639                 inplace = 1;
 640         }
 641
 642         while (fgets(line, sizeof(line), in)) {
 643                 num++;
 644                 i = strlen(line) - 1;
 645                 if (line[i] != '\n') {
 646                         error("line %d too long: %.40s...", num, line);
 647                         skip = 1;
 648                         invalid = 1;
 649                         continue;
 650                 }
 651                 if (skip) {
 652                         skip = 0;
 653                         continue;
 654                 }
 655                 line[i] = '\0';
 656
 657                 /* Skip leading whitespace, empty and comment lines. */
 658                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 659                         ;
 660                 if (!*cp || *cp == '\n' || *cp == '#') {
 661                         if (inplace)
 662                                 fprintf(out, "%s\n", cp);
 663                         continue;
 664                 }
 665                 /* Find the end of the host name portion. */
 666                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 667                         ;
 668                 if (*kp == '\0' || *(kp + 1) == '\0') {
 669                         error("line %d missing key: %.40s...",
 670                             num, line);
 671                         invalid = 1;
 672                         continue;
 673                 }
 674                 *kp++ = '\0';
 675                 kp2 = kp;
 676
 677                 public = key_new(KEY_RSA1);
 678                 if (key_read(public, &kp) != 1) {
 679                         kp = kp2;
 680                         key_free(public);
 681                         public = key_new(KEY_UNSPEC);
 682                         if (key_read(public, &kp) != 1) {
 683                                 error("line %d invalid key: %.40s...",
 684                                     num, line);
 685                                 key_free(public);
 686                                 invalid = 1;
 687                                 continue;
 688                         }
 689                 }
 690
 691                 if (*cp == HASH_DELIM) {
 692                         if (find_host || delete_host) {
 693                                 cp2 = host_hash(name, cp, strlen(cp));
 694                                 if (cp2 == NULL) {
 695                                         error("line %d: invalid hashed "
 696                                             "name: %.64s...", num, line);
 697                                         invalid = 1;
 698                                         continue;
 699                                 }
 700                                 c = (strcmp(cp2, cp) == 0);
 701                                 if (find_host && c) {
 702                                         printf("# Host %s found: "
 703                                             "line %d type %s\n", name,
 704                                             num, key_type(public));
 705                                         print_host(out, cp, public, 0);
 706                                 }
 707                                 if (delete_host && !c)
 708                                         print_host(out, cp, public, 0);
 709                         } else if (hash_hosts)
 710                                 print_host(out, cp, public, 0);
 711                 } else {
 712                         if (find_host || delete_host) {
 713                                 c = (match_hostname(name, cp,
 714                                     strlen(cp)) == 1);
 715                                 if (find_host && c) {
 716                                         printf("# Host %s found: "
 717                                             "line %d type %s\n", name,
 718                                             num, key_type(public));
 719                                         print_host(out, cp, public, hash_hosts);
 720                                 }
 721                                 if (delete_host && !c)
 722                                         print_host(out, cp, public, 0);
 723                         } else if (hash_hosts) {
 724                                 for (cp2 = strsep(&cp, ",");
 725                                     cp2 != NULL && *cp2 != '\0';
 726                                     cp2 = strsep(&cp, ",")) {
 727                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 728                                                 fprintf(stderr, "Warning: "
 729                                                     "ignoring host name with "
 730                                                     "metacharacters: %.64s\n",
 731                                                     cp2);
 732                                         else
 733                                                 print_host(out, cp2, public, 1);
 734                                 }
 735                                 has_unhashed = 1;
 736                         }
 737                 }
 738                 key_free(public);
 739         }
 740         fclose(in);
 741
 742         if (invalid) {
 743                 fprintf(stderr, "%s is not a valid known_host file.\n",
 744                     identity_file);
 745                 if (inplace) {
 746                         fprintf(stderr, "Not replacing existing known_hosts "
 747                             "file because of errors\n");
 748                         fclose(out);
 749                         unlink(tmp);
 750                 }
 751                 exit(1);
 752         }
 753
 754         if (inplace) {
 755                 fclose(out);
 756
 757                 /* Backup existing file */
 758                 if (unlink(old) == -1 && errno != ENOENT)
 759                         fatal("unlink %.100s: %s", old, strerror(errno));
 760                 if (link(identity_file, old) == -1)
 761                         fatal("link %.100s to %.100s: %s", identity_file, old,
 762                             strerror(errno));
 763                 /* Move new one into place */
 764                 if (rename(tmp, identity_file) == -1) {
 765                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 766                             strerror(errno));
 767                         unlink(tmp);
 768                         unlink(old);
 769                         exit(1);
 770                 }
 771
 772                 fprintf(stderr, "%s updated.\n", identity_file);
 773                 fprintf(stderr, "Original contents retained as %s\n", old);
 774                 if (has_unhashed) {
 775                         fprintf(stderr, "WARNING: %s contains unhashed "
 776                             "entries\n", old);
 777                         fprintf(stderr, "Delete this file to ensure privacy "
 778                             "of hostnames\n");
 779                 }
 780         }
 781
 782         exit(0);
 783 }
 784
 785 /*
 786  * Perform changing a passphrase.  The argument is the passwd structure
 787  * for the current user.
 788  */
 789 static void
 790 do_change_passphrase(struct passwd *pw)
 791 {
 792         char *comment;
 793         char *old_passphrase, *passphrase1, *passphrase2;
 794         struct stat st;
 795         Key *private;
 796
 797         if (!have_identity)
 798                 ask_filename(pw, "Enter file in which the key is");
 799         if (stat(identity_file, &st) < 0) {
 800                 perror(identity_file);
 801                 exit(1);
 802         }
 803         /* Try to load the file with empty passphrase. */
 804         private = key_load_private(identity_file, "", &comment);
 805         if (private == NULL) {
 806                 if (identity_passphrase)
 807                         old_passphrase = xstrdup(identity_passphrase);
 808                 else
 809                         old_passphrase =
 810                             read_passphrase("Enter old passphrase: ",
 811                             RP_ALLOW_STDIN);
 812                 private = key_load_private(identity_file, old_passphrase,
 813                     &comment);
 814                 memset(old_passphrase, 0, strlen(old_passphrase));
 815                 xfree(old_passphrase);
 816                 if (private == NULL) {
 817                         printf("Bad passphrase.\n");
 818                         exit(1);
 819                 }
 820         }
 821         printf("Key has comment '%s'\n", comment);
 822
 823         /* Ask the new passphrase (twice). */
 824         if (identity_new_passphrase) {
 825                 passphrase1 = xstrdup(identity_new_passphrase);
 826                 passphrase2 = NULL;
 827         } else {
 828                 passphrase1 =
 829                         read_passphrase("Enter new passphrase (empty for no "
 830                             "passphrase): ", RP_ALLOW_STDIN);
 831                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 832                     RP_ALLOW_STDIN);
 833
 834                 /* Verify that they are the same. */
 835                 if (strcmp(passphrase1, passphrase2) != 0) {
 836                         memset(passphrase1, 0, strlen(passphrase1));
 837                         memset(passphrase2, 0, strlen(passphrase2));
 838                         xfree(passphrase1);
 839                         xfree(passphrase2);
 840                         printf("Pass phrases do not match.  Try again.\n");
 841                         exit(1);
 842                 }
 843                 /* Destroy the other copy. */
 844                 memset(passphrase2, 0, strlen(passphrase2));
 845                 xfree(passphrase2);
 846         }
 847
 848         /* Save the file using the new passphrase. */
 849         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 850                 printf("Saving the key failed: %s.\n", identity_file);
 851                 memset(passphrase1, 0, strlen(passphrase1));
 852                 xfree(passphrase1);
 853                 key_free(private);
 854                 xfree(comment);
 855                 exit(1);
 856         }
 857         /* Destroy the passphrase and the copy of the key in memory. */
 858         memset(passphrase1, 0, strlen(passphrase1));
 859         xfree(passphrase1);
 860         key_free(private);               /* Destroys contents */
 861         xfree(comment);
 862
 863         printf("Your identification has been saved with the new passphrase.\n");
 864         exit(0);
 865 }
 866
 867 /*
 868  * Print the SSHFP RR.
 869  */
 870 static int
 871 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 872 {
 873         Key *public;
 874         char *comment = NULL;
 875         struct stat st;
 876
 877         if (fname == NULL)
 878                 ask_filename(pw, "Enter file in which the key is");
 879         if (stat(fname, &st) < 0) {
 880                 if (errno == ENOENT)
 881                         return 0;
 882                 perror(fname);
 883                 exit(1);
 884         }
 885         public = key_load_public(fname, &comment);
 886         if (public != NULL) {
 887                 export_dns_rr(hname, public, stdout, print_generic);
 888                 key_free(public);
 889                 xfree(comment);
 890                 return 1;
 891         }
 892         if (comment)
 893                 xfree(comment);
 894
 895         printf("failed to read v2 public key from %s.\n", fname);
 896         exit(1);
 897 }
 898
 899 /*
 900  * Change the comment of a private key file.
 901  */
 902 static void
 903 do_change_comment(struct passwd *pw)
 904 {
 905         char new_comment[1024], *comment, *passphrase;
 906         Key *private;
 907         Key *public;
 908         struct stat st;
 909         FILE *f;
 910         int fd;
 911
 912         if (!have_identity)
 913                 ask_filename(pw, "Enter file in which the key is");
 914         if (stat(identity_file, &st) < 0) {
 915                 perror(identity_file);
 916                 exit(1);
 917         }
 918         private = key_load_private(identity_file, "", &comment);
 919         if (private == NULL) {
 920                 if (identity_passphrase)
 921                         passphrase = xstrdup(identity_passphrase);
 922                 else if (identity_new_passphrase)
 923                         passphrase = xstrdup(identity_new_passphrase);
 924                 else
 925                         passphrase = read_passphrase("Enter passphrase: ",
 926                             RP_ALLOW_STDIN);
 927                 /* Try to load using the passphrase. */
 928                 private = key_load_private(identity_file, passphrase, &comment);
 929                 if (private == NULL) {
 930                         memset(passphrase, 0, strlen(passphrase));
 931                         xfree(passphrase);
 932                         printf("Bad passphrase.\n");
 933                         exit(1);
 934                 }
 935         } else {
 936                 passphrase = xstrdup("");
 937         }
 938         if (private->type != KEY_RSA1) {
 939                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 940                 key_free(private);
 941                 exit(1);
 942         }
 943         printf("Key now has comment '%s'\n", comment);
 944
 945         if (identity_comment) {
 946                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 947         } else {
 948                 printf("Enter new comment: ");
 949                 fflush(stdout);
 950                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 951                         memset(passphrase, 0, strlen(passphrase));
 952                         key_free(private);
 953                         exit(1);
 954                 }
 955                 if (strchr(new_comment, '\n'))
 956                         *strchr(new_comment, '\n') = 0;
 957         }
 958
 959         /* Save the file using the new passphrase. */
 960         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 961                 printf("Saving the key failed: %s.\n", identity_file);
 962                 memset(passphrase, 0, strlen(passphrase));
 963                 xfree(passphrase);
 964                 key_free(private);
 965                 xfree(comment);
 966                 exit(1);
 967         }
 968         memset(passphrase, 0, strlen(passphrase));
 969         xfree(passphrase);
 970         public = key_from_private(private);
 971         key_free(private);
 972
 973         strlcat(identity_file, ".pub", sizeof(identity_file));
 974         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 975         if (fd == -1) {
 976                 printf("Could not save your public key in %s\n", identity_file);
 977                 exit(1);
 978         }
 979         f = fdopen(fd, "w");
 980         if (f == NULL) {
 981                 printf("fdopen %s failed", identity_file);
 982                 exit(1);
 983         }
 984         if (!key_write(public, f))
 985                 fprintf(stderr, "write key failed");
 986         key_free(public);
 987         fprintf(f, " %s\n", new_comment);
 988         fclose(f);
 989
 990         xfree(comment);
 991
 992         printf("The comment in your key file has been changed.\n");
 993         exit(0);
 994 }
 995
 996 static void
 997 usage(void)
 998 {
 999         fprintf(stderr, "Usage: %s [options]\n", __progname);
1000         fprintf(stderr, "Options:\n");
1001         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1002         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1003         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1004         fprintf(stderr, "  -C comment  Provide new comment.\n");
1005         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1006 #ifdef SMARTCARD
1007         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1008 #endif /* SMARTCARD */
1009         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1010         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1011         fprintf(stderr, "  -f filename Filename of the key file.\n");
1012         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1013         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1014         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1015         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1016         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1017         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1018         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1019         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1020         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1021         fprintf(stderr, "  -q          Quiet.\n");
1022         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1023         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1024         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1025         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1026         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1027 #ifdef SMARTCARD
1028         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1029 #endif /* SMARTCARD */
1030         fprintf(stderr, "  -v          Verbose.\n");
1031         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1032         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1033
1034         exit(1);
1035 }
1036
1037 /*
1038  * Main program for key management.
1039  */
1040 int
1041 main(int ac, char **av)
1042 {
1043         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1044         char out_file[MAXPATHLEN], *reader_id = NULL;
1045         char *rr_hostname = NULL;
1046         Key *private, *public;
1047         struct passwd *pw;
1048         struct stat st;
1049         int opt, type, fd, download = 0;
1050         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1051         int do_gen_candidates = 0, do_screen_candidates = 0;
1052         int log_level = SYSLOG_LEVEL_INFO;
1053         BIGNUM *start = NULL;
1054         FILE *f;
1055         const char *errstr;
1056
1057         extern int optind;
1058         extern char *optarg;
1059
1060         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1061         sanitise_stdfd();
1062
1063         __progname = ssh_get_progname(av[0]);
1064
1065         SSLeay_add_all_algorithms();
1066         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1067
1068         init_rng();
1069         seed_rng();
1070
1071         /* we need this for the home * directory.  */
1072         pw = getpwuid(getuid());
1073         if (!pw) {
1074                 printf("You don't exist, go away!\n");
1075                 exit(1);
1076         }
1077         if (gethostname(hostname, sizeof(hostname)) < 0) {
1078                 perror("gethostname");
1079                 exit(1);
1080         }
1081
1082         while ((opt = getopt(ac, av,
1083             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1084                 switch (opt) {
1085                 case 'b':
1086                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1087                         if (errstr)
1088                                 fatal("Bits has bad value %s (%s)",
1089                                         optarg, errstr);
1090                         break;
1091                 case 'F':
1092                         find_host = 1;
1093                         rr_hostname = optarg;
1094                         break;
1095                 case 'H':
1096                         hash_hosts = 1;
1097                         break;
1098                 case 'R':
1099                         delete_host = 1;
1100                         rr_hostname = optarg;
1101                         break;
1102                 case 'l':
1103                         print_fingerprint = 1;
1104                         break;
1105                 case 'B':
1106                         print_bubblebabble = 1;
1107                         break;
1108                 case 'p':
1109                         change_passphrase = 1;
1110                         break;
1111                 case 'c':
1112                         change_comment = 1;
1113                         break;
1114                 case 'f':
1115                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1116                             sizeof(identity_file))
1117                                 fatal("Identity filename too long");
1118                         have_identity = 1;
1119                         break;
1120                 case 'g':
1121                         print_generic = 1;
1122                         break;
1123                 case 'P':
1124                         identity_passphrase = optarg;
1125                         break;
1126                 case 'N':
1127                         identity_new_passphrase = optarg;
1128                         break;
1129                 case 'C':
1130                         identity_comment = optarg;
1131                         break;
1132                 case 'q':
1133                         quiet = 1;
1134                         break;
1135                 case 'e':
1136                 case 'x':
1137                         /* export key */
1138                         convert_to_ssh2 = 1;
1139                         break;
1140                 case 'i':
1141                 case 'X':
1142                         /* import key */
1143                         convert_from_ssh2 = 1;
1144                         break;
1145                 case 'y':
1146                         print_public = 1;
1147                         break;
1148                 case 'd':
1149                         key_type_name = "dsa";
1150                         break;
1151                 case 't':
1152                         key_type_name = optarg;
1153                         break;
1154                 case 'D':
1155                         download = 1;
1156                         /*FALLTHROUGH*/
1157                 case 'U':
1158                         reader_id = optarg;
1159                         break;
1160                 case 'v':
1161                         if (log_level == SYSLOG_LEVEL_INFO)
1162                                 log_level = SYSLOG_LEVEL_DEBUG1;
1163                         else {
1164                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1165                                     log_level < SYSLOG_LEVEL_DEBUG3)
1166                                         log_level++;
1167                         }
1168                         break;
1169                 case 'r':
1170                         rr_hostname = optarg;
1171                         break;
1172                 case 'W':
1173                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1174                             UINT_MAX, &errstr);
1175                         if (errstr)
1176                                 fatal("Desired generator has bad value: %s (%s)",
1177                                         optarg, errstr);
1178                         break;
1179                 case 'a':
1180                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1181                         if (errstr)
1182                                 fatal("Invalid number of trials: %s (%s)",
1183                                         optarg, errstr);
1184                         break;
1185                 case 'M':
1186                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1187                         if (errstr) {
1188                                 fatal("Memory limit is %s: %s", errstr, optarg);
1189                         }
1190                         break;
1191                 case 'G':
1192                         do_gen_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 'T':
1198                         do_screen_candidates = 1;
1199                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1200                             sizeof(out_file))
1201                                 fatal("Output filename too long");
1202                         break;
1203                 case 'S':
1204                         /* XXX - also compare length against bits */
1205                         if (BN_hex2bn(&start, optarg) == 0)
1206                                 fatal("Invalid start point.");
1207                         break;
1208                 case '?':
1209                 default:
1210                         usage();
1211                 }
1212         }
1213
1214         /* reinit */
1215         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1216
1217         if (optind < ac) {
1218                 printf("Too many arguments.\n");
1219                 usage();
1220         }
1221         if (change_passphrase && change_comment) {
1222                 printf("Can only have one of -p and -c.\n");
1223                 usage();
1224         }
1225         if (delete_host || hash_hosts || find_host)
1226                 do_known_hosts(pw, rr_hostname);
1227         if (print_fingerprint || print_bubblebabble)
1228                 do_fingerprint(pw);
1229         if (change_passphrase)
1230                 do_change_passphrase(pw);
1231         if (change_comment)
1232                 do_change_comment(pw);
1233         if (convert_to_ssh2)
1234                 do_convert_to_ssh2(pw);
1235         if (convert_from_ssh2)
1236                 do_convert_from_ssh2(pw);
1237         if (print_public)
1238                 do_print_public(pw);
1239         if (rr_hostname != NULL) {
1240                 unsigned int n = 0;
1241
1242                 if (have_identity) {
1243                         n = do_print_resource_record(pw,
1244                             identity_file, rr_hostname);
1245                         if (n == 0) {
1246                                 perror(identity_file);
1247                                 exit(1);
1248                         }
1249                         exit(0);
1250                 } else {
1251
1252                         n += do_print_resource_record(pw,
1253                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1254                         n += do_print_resource_record(pw,
1255                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1256
1257                         if (n == 0)
1258                                 fatal("no keys found.");
1259                         exit(0);
1260                 }
1261         }
1262         if (reader_id != NULL) {
1263 #ifdef SMARTCARD
1264                 if (download)
1265                         do_download(pw, reader_id);
1266                 else
1267                         do_upload(pw, reader_id);
1268 #else /* SMARTCARD */
1269                 fatal("no support for smartcards.");
1270 #endif /* SMARTCARD */
1271         }
1272
1273         if (do_gen_candidates) {
1274                 FILE *out = fopen(out_file, "w");
1275
1276                 if (out == NULL) {
1277                         error("Couldn't open modulus candidate file \"%s\": %s",
1278                             out_file, strerror(errno));
1279                         return (1);
1280                 }
1281                 if (bits == 0)
1282                         bits = DEFAULT_BITS;
1283                 if (gen_candidates(out, memory, bits, start) != 0)
1284                         fatal("modulus candidate generation failed");
1285
1286                 return (0);
1287         }
1288
1289         if (do_screen_candidates) {
1290                 FILE *in;
1291                 FILE *out = fopen(out_file, "w");
1292
1293                 if (have_identity && strcmp(identity_file, "-") != 0) {
1294                         if ((in = fopen(identity_file, "r")) == NULL) {
1295                                 fatal("Couldn't open modulus candidate "
1296                                     "file \"%s\": %s", identity_file,
1297                                     strerror(errno));
1298                         }
1299                 } else
1300                         in = stdin;
1301
1302                 if (out == NULL) {
1303                         fatal("Couldn't open moduli file \"%s\": %s",
1304                             out_file, strerror(errno));
1305                 }
1306                 if (prime_test(in, out, trials, generator_wanted) != 0)
1307                         fatal("modulus screening failed");
1308                 return (0);
1309         }
1310
1311         arc4random_stir();
1312
1313         if (key_type_name == NULL)
1314                 key_type_name = "rsa";
1315
1316         type = key_type_from_name(key_type_name);
1317         if (type == KEY_UNSPEC) {
1318                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1319                 exit(1);
1320         }
1321         if (bits == 0)
1322                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1323         if (type == KEY_DSA && bits != 1024)
1324                 fatal("DSA keys must be 1024 bits");
1325         if (!quiet)
1326                 printf("Generating public/private %s key pair.\n", key_type_name);
1327         private = key_generate(type, bits);
1328         if (private == NULL) {
1329                 fprintf(stderr, "key_generate failed");
1330                 exit(1);
1331         }
1332         public  = key_from_private(private);
1333
1334         if (!have_identity)
1335                 ask_filename(pw, "Enter file in which to save the key");
1336
1337         /* Create ~/.ssh directory if it doesn't already exist. */
1338         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1339         if (strstr(identity_file, dotsshdir) != NULL &&
1340             stat(dotsshdir, &st) < 0) {
1341                 if (mkdir(dotsshdir, 0700) < 0)
1342                         error("Could not create directory '%s'.", dotsshdir);
1343                 else if (!quiet)
1344                         printf("Created directory '%s'.\n", dotsshdir);
1345         }
1346         /* If the file already exists, ask the user to confirm. */
1347         if (stat(identity_file, &st) >= 0) {
1348                 char yesno[3];
1349                 printf("%s already exists.\n", identity_file);
1350                 printf("Overwrite (y/n)? ");
1351                 fflush(stdout);
1352                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1353                         exit(1);
1354                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1355                         exit(1);
1356         }
1357         /* Ask for a passphrase (twice). */
1358         if (identity_passphrase)
1359                 passphrase1 = xstrdup(identity_passphrase);
1360         else if (identity_new_passphrase)
1361                 passphrase1 = xstrdup(identity_new_passphrase);
1362         else {
1363 passphrase_again:
1364                 passphrase1 =
1365                         read_passphrase("Enter passphrase (empty for no "
1366                             "passphrase): ", RP_ALLOW_STDIN);
1367                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1368                     RP_ALLOW_STDIN);
1369                 if (strcmp(passphrase1, passphrase2) != 0) {
1370                         /*
1371                          * The passphrases do not match.  Clear them and
1372                          * retry.
1373                          */
1374                         memset(passphrase1, 0, strlen(passphrase1));
1375                         memset(passphrase2, 0, strlen(passphrase2));
1376                         xfree(passphrase1);
1377                         xfree(passphrase2);
1378                         printf("Passphrases do not match.  Try again.\n");
1379                         goto passphrase_again;
1380                 }
1381                 /* Clear the other copy of the passphrase. */
1382                 memset(passphrase2, 0, strlen(passphrase2));
1383                 xfree(passphrase2);
1384         }
1385
1386         if (identity_comment) {
1387                 strlcpy(comment, identity_comment, sizeof(comment));
1388         } else {
1389                 /* Create default commend field for the passphrase. */
1390                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1391         }
1392
1393         /* Save the key with the given passphrase and comment. */
1394         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1395                 printf("Saving the key failed: %s.\n", identity_file);
1396                 memset(passphrase1, 0, strlen(passphrase1));
1397                 xfree(passphrase1);
1398                 exit(1);
1399         }
1400         /* Clear the passphrase. */
1401         memset(passphrase1, 0, strlen(passphrase1));
1402         xfree(passphrase1);
1403
1404         /* Clear the private key and the random number generator. */
1405         key_free(private);
1406         arc4random_stir();
1407
1408         if (!quiet)
1409                 printf("Your identification has been saved in %s.\n", identity_file);
1410
1411         strlcat(identity_file, ".pub", sizeof(identity_file));
1412         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1413         if (fd == -1) {
1414                 printf("Could not save your public key in %s\n", identity_file);
1415                 exit(1);
1416         }
1417         f = fdopen(fd, "w");
1418         if (f == NULL) {
1419                 printf("fdopen %s failed", identity_file);
1420                 exit(1);
1421         }
1422         if (!key_write(public, f))
1423                 fprintf(stderr, "write key failed");
1424         fprintf(f, " %s\n", comment);
1425         fclose(f);
1426
1427         if (!quiet) {
1428                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1429                 printf("Your public key has been saved in %s.\n",
1430                     identity_file);
1431                 printf("The key fingerprint is:\n");
1432                 printf("%s %s\n", fp, comment);
1433                 xfree(fp);
1434         }
1435
1436         key_free(public);
1437         exit(0);
1438 }