crypto/openssh-4/ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.160 2007/01/21 01:41:54 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 #include <sys/param.h>
  21
  22 #include <openssl/evp.h>
  23 #include <openssl/pem.h>
  24
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <netdb.h>
  28 #ifdef HAVE_PATHS_H
  29 # include <paths.h>
  30 #endif
  31 #include <pwd.h>
  32 #include <stdarg.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <unistd.h>
  37
  38 #include "xmalloc.h"
  39 #include "key.h"
  40 #include "rsa.h"
  41 #include "authfile.h"
  42 #include "uuencode.h"
  43 #include "buffer.h"
  44 #include "pathnames.h"
  45 #include "log.h"
  46 #include "misc.h"
  47 #include "match.h"
  48 #include "hostfile.h"
  49 #include "dns.h"
  50
  51 #ifdef SMARTCARD
  52 #include "scard.h"
  53 #endif
  54
  55 /* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
  56 #define DEFAULT_BITS            2048
  57 #define DEFAULT_BITS_DSA        1024
  58 u_int32_t bits = 0;
  59
  60 /*
  61  * Flag indicating that we just want to change the passphrase.  This can be
  62  * set on the command line.
  63  */
  64 int change_passphrase = 0;
  65
  66 /*
  67  * Flag indicating that we just want to change the comment.  This can be set
  68  * on the command line.
  69  */
  70 int change_comment = 0;
  71
  72 int quiet = 0;
  73
  74 /* Flag indicating that we want to hash a known_hosts file */
  75 int hash_hosts = 0;
  76 /* Flag indicating that we want lookup a host in known_hosts file */
  77 int find_host = 0;
  78 /* Flag indicating that we want to delete a host from a known_hosts file */
  79 int delete_host = 0;
  80
  81 /* Flag indicating that we just want to see the key fingerprint */
  82 int print_fingerprint = 0;
  83 int print_bubblebabble = 0;
  84
  85 /* The identity file name, given on the command line or entered by the user. */
  86 char identity_file[1024];
  87 int have_identity = 0;
  88
  89 /* This is set to the passphrase if given on the command line. */
  90 char *identity_passphrase = NULL;
  91
  92 /* This is set to the new passphrase if given on the command line. */
  93 char *identity_new_passphrase = NULL;
  94
  95 /* This is set to the new comment if given on the command line. */
  96 char *identity_comment = NULL;
  97
  98 /* Dump public key file in format used by real and the original SSH 2 */
  99 int convert_to_ssh2 = 0;
 100 int convert_from_ssh2 = 0;
 101 int print_public = 0;
 102 int print_generic = 0;
 103
 104 char *key_type_name = NULL;
 105
 106 /* argv0 */
 107 extern char *__progname;
 108
 109 char hostname[MAXHOSTNAMELEN];
 110
 111 /* moduli.c */
 112 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 113 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 114
 115 static void
 116 ask_filename(struct passwd *pw, const char *prompt)
 117 {
 118         char buf[1024];
 119         char *name = NULL;
 120
 121         if (key_type_name == NULL)
 122                 name = _PATH_SSH_CLIENT_ID_RSA;
 123         else {
 124                 switch (key_type_from_name(key_type_name)) {
 125                 case KEY_RSA1:
 126                         name = _PATH_SSH_CLIENT_IDENTITY;
 127                         break;
 128                 case KEY_DSA:
 129                         name = _PATH_SSH_CLIENT_ID_DSA;
 130                         break;
 131                 case KEY_RSA:
 132                         name = _PATH_SSH_CLIENT_ID_RSA;
 133                         break;
 134                 default:
 135                         fprintf(stderr, "bad key type");
 136                         exit(1);
 137                         break;
 138                 }
 139         }
 140         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 141         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 142         if (fgets(buf, sizeof(buf), stdin) == NULL)
 143                 exit(1);
 144         if (strchr(buf, '\n'))
 145                 *strchr(buf, '\n') = 0;
 146         if (strcmp(buf, "") != 0)
 147                 strlcpy(identity_file, buf, sizeof(identity_file));
 148         have_identity = 1;
 149 }
 150
 151 static Key *
 152 load_identity(char *filename)
 153 {
 154         char *pass;
 155         Key *prv;
 156
 157         prv = key_load_private(filename, "", NULL);
 158         if (prv == NULL) {
 159                 if (identity_passphrase)
 160                         pass = xstrdup(identity_passphrase);
 161                 else
 162                         pass = read_passphrase("Enter passphrase: ",
 163                             RP_ALLOW_STDIN);
 164                 prv = key_load_private(filename, pass, NULL);
 165                 memset(pass, 0, strlen(pass));
 166                 xfree(pass);
 167         }
 168         return prv;
 169 }
 170
 171 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 172 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 173 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 174 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 175
 176 static void
 177 do_convert_to_ssh2(struct passwd *pw)
 178 {
 179         Key *k;
 180         u_int len;
 181         u_char *blob;
 182         struct stat st;
 183
 184         if (!have_identity)
 185                 ask_filename(pw, "Enter file in which the key is");
 186         if (stat(identity_file, &st) < 0) {
 187                 perror(identity_file);
 188                 exit(1);
 189         }
 190         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 191                 if ((k = load_identity(identity_file)) == NULL) {
 192                         fprintf(stderr, "load failed\n");
 193                         exit(1);
 194                 }
 195         }
 196         if (k->type == KEY_RSA1) {
 197                 fprintf(stderr, "version 1 keys are not supported\n");
 198                 exit(1);
 199         }
 200         if (key_to_blob(k, &blob, &len) <= 0) {
 201                 fprintf(stderr, "key_to_blob failed\n");
 202                 exit(1);
 203         }
 204         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 205         fprintf(stdout,
 206             "Comment: \"%u-bit %s, converted from OpenSSH by %s@%s\"\n",
 207             key_size(k), key_type(k),
 208             pw->pw_name, hostname);
 209         dump_base64(stdout, blob, len);
 210         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 211         key_free(k);
 212         xfree(blob);
 213         exit(0);
 214 }
 215
 216 static void
 217 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 218 {
 219         u_int bignum_bits = buffer_get_int(b);
 220         u_int bytes = (bignum_bits + 7) / 8;
 221
 222         if (buffer_len(b) < bytes)
 223                 fatal("buffer_get_bignum_bits: input buffer too small: "
 224                     "need %d have %d", bytes, buffer_len(b));
 225         if (BN_bin2bn(buffer_ptr(b), bytes, value) == NULL)
 226                 fatal("buffer_get_bignum_bits: BN_bin2bn failed");
 227         buffer_consume(b, bytes);
 228 }
 229
 230 static Key *
 231 do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
 232 {
 233         Buffer b;
 234         Key *key = NULL;
 235         char *type, *cipher;
 236         u_char *sig, data[] = "abcde12345";
 237         int magic, rlen, ktype, i1, i2, i3, i4;
 238         u_int slen;
 239         u_long e;
 240
 241         buffer_init(&b);
 242         buffer_append(&b, blob, blen);
 243
 244         magic = buffer_get_int(&b);
 245         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 246                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 247                 buffer_free(&b);
 248                 return NULL;
 249         }
 250         i1 = buffer_get_int(&b);
 251         type   = buffer_get_string(&b, NULL);
 252         cipher = buffer_get_string(&b, NULL);
 253         i2 = buffer_get_int(&b);
 254         i3 = buffer_get_int(&b);
 255         i4 = buffer_get_int(&b);
 256         debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
 257         if (strcmp(cipher, "none") != 0) {
 258                 error("unsupported cipher %s", cipher);
 259                 xfree(cipher);
 260                 buffer_free(&b);
 261                 xfree(type);
 262                 return NULL;
 263         }
 264         xfree(cipher);
 265
 266         if (strstr(type, "dsa")) {
 267                 ktype = KEY_DSA;
 268         } else if (strstr(type, "rsa")) {
 269                 ktype = KEY_RSA;
 270         } else {
 271                 buffer_free(&b);
 272                 xfree(type);
 273                 return NULL;
 274         }
 275         key = key_new_private(ktype);
 276         xfree(type);
 277
 278         switch (key->type) {
 279         case KEY_DSA:
 280                 buffer_get_bignum_bits(&b, key->dsa->p);
 281                 buffer_get_bignum_bits(&b, key->dsa->g);
 282                 buffer_get_bignum_bits(&b, key->dsa->q);
 283                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 284                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 285                 break;
 286         case KEY_RSA:
 287                 e = buffer_get_char(&b);
 288                 debug("e %lx", e);
 289                 if (e < 30) {
 290                         e <<= 8;
 291                         e += buffer_get_char(&b);
 292                         debug("e %lx", e);
 293                         e <<= 8;
 294                         e += buffer_get_char(&b);
 295                         debug("e %lx", e);
 296                 }
 297                 if (!BN_set_word(key->rsa->e, e)) {
 298                         buffer_free(&b);
 299                         key_free(key);
 300                         return NULL;
 301                 }
 302                 buffer_get_bignum_bits(&b, key->rsa->d);
 303                 buffer_get_bignum_bits(&b, key->rsa->n);
 304                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 305                 buffer_get_bignum_bits(&b, key->rsa->q);
 306                 buffer_get_bignum_bits(&b, key->rsa->p);
 307                 rsa_generate_additional_parameters(key->rsa);
 308                 break;
 309         }
 310         rlen = buffer_len(&b);
 311         if (rlen != 0)
 312                 error("do_convert_private_ssh2_from_blob: "
 313                     "remaining bytes in key blob %d", rlen);
 314         buffer_free(&b);
 315
 316         /* try the key */
 317         key_sign(key, &sig, &slen, data, sizeof(data));
 318         key_verify(key, sig, slen, data, sizeof(data));
 319         xfree(sig);
 320         return key;
 321 }
 322
 323 static int
 324 get_line(FILE *fp, char *line, size_t len)
 325 {
 326         int c;
 327         size_t pos = 0;
 328
 329         line[0] = '\0';
 330         while ((c = fgetc(fp)) != EOF) {
 331                 if (pos >= len - 1) {
 332                         fprintf(stderr, "input line too long.\n");
 333                         exit(1);
 334                 }
 335                 switch (c) {
 336                 case '\r':
 337                         c = fgetc(fp);
 338                         if (c != EOF && c != '\n' && ungetc(c, fp) == EOF) {
 339                                 fprintf(stderr, "unget: %s\n", strerror(errno));
 340                                 exit(1);
 341                         }
 342                         return pos;
 343                 case '\n':
 344                         return pos;
 345                 }
 346                 line[pos++] = c;
 347                 line[pos] = '\0';
 348         }
 349         /* We reached EOF */
 350         return -1;
 351 }
 352
 353 static void
 354 do_convert_from_ssh2(struct passwd *pw)
 355 {
 356         Key *k;
 357         int blen;
 358         u_int len;
 359         char line[1024];
 360         u_char blob[8096];
 361         char encoded[8096];
 362         struct stat st;
 363         int escaped = 0, private = 0, ok;
 364         FILE *fp;
 365
 366         if (!have_identity)
 367                 ask_filename(pw, "Enter file in which the key is");
 368         if (stat(identity_file, &st) < 0) {
 369                 perror(identity_file);
 370                 exit(1);
 371         }
 372         fp = fopen(identity_file, "r");
 373         if (fp == NULL) {
 374                 perror(identity_file);
 375                 exit(1);
 376         }
 377         encoded[0] = '\0';
 378         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 379                 if (line[blen - 1] == '\\')
 380                         escaped++;
 381                 if (strncmp(line, "----", 4) == 0 ||
 382                     strstr(line, ": ") != NULL) {
 383                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 384                                 private = 1;
 385                         if (strstr(line, " END ") != NULL) {
 386                                 break;
 387                         }
 388                         /* fprintf(stderr, "ignore: %s", line); */
 389                         continue;
 390                 }
 391                 if (escaped) {
 392                         escaped--;
 393                         /* fprintf(stderr, "escaped: %s", line); */
 394                         continue;
 395                 }
 396                 strlcat(encoded, line, sizeof(encoded));
 397         }
 398         len = strlen(encoded);
 399         if (((len % 4) == 3) &&
 400             (encoded[len-1] == '=') &&
 401             (encoded[len-2] == '=') &&
 402             (encoded[len-3] == '='))
 403                 encoded[len-3] = '\0';
 404         blen = uudecode(encoded, blob, sizeof(blob));
 405         if (blen < 0) {
 406                 fprintf(stderr, "uudecode failed.\n");
 407                 exit(1);
 408         }
 409         k = private ?
 410             do_convert_private_ssh2_from_blob(blob, blen) :
 411             key_from_blob(blob, blen);
 412         if (k == NULL) {
 413                 fprintf(stderr, "decode blob failed.\n");
 414                 exit(1);
 415         }
 416         ok = private ?
 417             (k->type == KEY_DSA ?
 418                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 419                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 420             key_write(k, stdout);
 421         if (!ok) {
 422                 fprintf(stderr, "key write failed");
 423                 exit(1);
 424         }
 425         key_free(k);
 426         if (!private)
 427                 fprintf(stdout, "\n");
 428         fclose(fp);
 429         exit(0);
 430 }
 431
 432 static void
 433 do_print_public(struct passwd *pw)
 434 {
 435         Key *prv;
 436         struct stat st;
 437
 438         if (!have_identity)
 439                 ask_filename(pw, "Enter file in which the key is");
 440         if (stat(identity_file, &st) < 0) {
 441                 perror(identity_file);
 442                 exit(1);
 443         }
 444         prv = load_identity(identity_file);
 445         if (prv == NULL) {
 446                 fprintf(stderr, "load failed\n");
 447                 exit(1);
 448         }
 449         if (!key_write(prv, stdout))
 450                 fprintf(stderr, "key_write failed");
 451         key_free(prv);
 452         fprintf(stdout, "\n");
 453         exit(0);
 454 }
 455
 456 #ifdef SMARTCARD
 457 static void
 458 do_upload(struct passwd *pw, const char *sc_reader_id)
 459 {
 460         Key *prv = NULL;
 461         struct stat st;
 462         int ret;
 463
 464         if (!have_identity)
 465                 ask_filename(pw, "Enter file in which the key is");
 466         if (stat(identity_file, &st) < 0) {
 467                 perror(identity_file);
 468                 exit(1);
 469         }
 470         prv = load_identity(identity_file);
 471         if (prv == NULL) {
 472                 error("load failed");
 473                 exit(1);
 474         }
 475         ret = sc_put_key(prv, sc_reader_id);
 476         key_free(prv);
 477         if (ret < 0)
 478                 exit(1);
 479         logit("loading key done");
 480         exit(0);
 481 }
 482
 483 static void
 484 do_download(struct passwd *pw, const char *sc_reader_id)
 485 {
 486         Key **keys = NULL;
 487         int i;
 488
 489         keys = sc_get_keys(sc_reader_id, NULL);
 490         if (keys == NULL)
 491                 fatal("cannot read public key from smartcard");
 492         for (i = 0; keys[i]; i++) {
 493                 key_write(keys[i], stdout);
 494                 key_free(keys[i]);
 495                 fprintf(stdout, "\n");
 496         }
 497         xfree(keys);
 498         exit(0);
 499 }
 500 #endif /* SMARTCARD */
 501
 502 static void
 503 do_fingerprint(struct passwd *pw)
 504 {
 505         FILE *f;
 506         Key *public;
 507         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 508         int i, skip = 0, num = 1, invalid = 1;
 509         enum fp_rep rep;
 510         enum fp_type fptype;
 511         struct stat st;
 512
 513         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 514         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 515
 516         if (!have_identity)
 517                 ask_filename(pw, "Enter file in which the key is");
 518         if (stat(identity_file, &st) < 0) {
 519                 perror(identity_file);
 520                 exit(1);
 521         }
 522         public = key_load_public(identity_file, &comment);
 523         if (public != NULL) {
 524                 fp = key_fingerprint(public, fptype, rep);
 525                 printf("%u %s %s\n", key_size(public), fp, comment);
 526                 key_free(public);
 527                 xfree(comment);
 528                 xfree(fp);
 529                 exit(0);
 530         }
 531         if (comment) {
 532                 xfree(comment);
 533                 comment = NULL;
 534         }
 535
 536         f = fopen(identity_file, "r");
 537         if (f != NULL) {
 538                 while (fgets(line, sizeof(line), f)) {
 539                         i = strlen(line) - 1;
 540                         if (line[i] != '\n') {
 541                                 error("line %d too long: %.40s...", num, line);
 542                                 skip = 1;
 543                                 continue;
 544                         }
 545                         num++;
 546                         if (skip) {
 547                                 skip = 0;
 548                                 continue;
 549                         }
 550                         line[i] = '\0';
 551
 552                         /* Skip leading whitespace, empty and comment lines. */
 553                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 554                                 ;
 555                         if (!*cp || *cp == '\n' || *cp == '#')
 556                                 continue;
 557                         i = strtol(cp, &ep, 10);
 558                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 559                                 int quoted = 0;
 560                                 comment = cp;
 561                                 for (; *cp && (quoted || (*cp != ' ' &&
 562                                     *cp != '\t')); cp++) {
 563                                         if (*cp == '\\' && cp[1] == '"')
 564                                                 cp++;   /* Skip both */
 565                                         else if (*cp == '"')
 566                                                 quoted = !quoted;
 567                                 }
 568                                 if (!*cp)
 569                                         continue;
 570                                 *cp++ = '\0';
 571                         }
 572                         ep = cp;
 573                         public = key_new(KEY_RSA1);
 574                         if (key_read(public, &cp) != 1) {
 575                                 cp = ep;
 576                                 key_free(public);
 577                                 public = key_new(KEY_UNSPEC);
 578                                 if (key_read(public, &cp) != 1) {
 579                                         key_free(public);
 580                                         continue;
 581                                 }
 582                         }
 583                         comment = *cp ? cp : comment;
 584                         fp = key_fingerprint(public, fptype, rep);
 585                         printf("%u %s %s\n", key_size(public), fp,
 586                             comment ? comment : "no comment");
 587                         xfree(fp);
 588                         key_free(public);
 589                         invalid = 0;
 590                 }
 591                 fclose(f);
 592         }
 593         if (invalid) {
 594                 printf("%s is not a public key file.\n", identity_file);
 595                 exit(1);
 596         }
 597         exit(0);
 598 }
 599
 600 static void
 601 print_host(FILE *f, char *name, Key *public, int hash)
 602 {
 603         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 604                 fatal("hash_host failed");
 605         fprintf(f, "%s ", name);
 606         if (!key_write(public, f))
 607                 fatal("key_write failed");
 608         fprintf(f, "\n");
 609 }
 610
 611 static void
 612 do_known_hosts(struct passwd *pw, const char *name)
 613 {
 614         FILE *in, *out = stdout;
 615         Key *public;
 616         char *cp, *cp2, *kp, *kp2;
 617         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 618         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 619
 620         if (!have_identity) {
 621                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 622                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 623                     sizeof(identity_file))
 624                         fatal("Specified known hosts path too long");
 625                 xfree(cp);
 626                 have_identity = 1;
 627         }
 628         if ((in = fopen(identity_file, "r")) == NULL)
 629                 fatal("fopen: %s", strerror(errno));
 630
 631         /*
 632          * Find hosts goes to stdout, hash and deletions happen in-place
 633          * A corner case is ssh-keygen -HF foo, which should go to stdout
 634          */
 635         if (!find_host && (hash_hosts || delete_host)) {
 636                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 637                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 638                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 639                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 640                         fatal("known_hosts path too long");
 641                 umask(077);
 642                 if ((c = mkstemp(tmp)) == -1)
 643                         fatal("mkstemp: %s", strerror(errno));
 644                 if ((out = fdopen(c, "w")) == NULL) {
 645                         c = errno;
 646                         unlink(tmp);
 647                         fatal("fdopen: %s", strerror(c));
 648                 }
 649                 inplace = 1;
 650         }
 651
 652         while (fgets(line, sizeof(line), in)) {
 653                 num++;
 654                 i = strlen(line) - 1;
 655                 if (line[i] != '\n') {
 656                         error("line %d too long: %.40s...", num, line);
 657                         skip = 1;
 658                         invalid = 1;
 659                         continue;
 660                 }
 661                 if (skip) {
 662                         skip = 0;
 663                         continue;
 664                 }
 665                 line[i] = '\0';
 666
 667                 /* Skip leading whitespace, empty and comment lines. */
 668                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 669                         ;
 670                 if (!*cp || *cp == '\n' || *cp == '#') {
 671                         if (inplace)
 672                                 fprintf(out, "%s\n", cp);
 673                         continue;
 674                 }
 675                 /* Find the end of the host name portion. */
 676                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 677                         ;
 678                 if (*kp == '\0' || *(kp + 1) == '\0') {
 679                         error("line %d missing key: %.40s...",
 680                             num, line);
 681                         invalid = 1;
 682                         continue;
 683                 }
 684                 *kp++ = '\0';
 685                 kp2 = kp;
 686
 687                 public = key_new(KEY_RSA1);
 688                 if (key_read(public, &kp) != 1) {
 689                         kp = kp2;
 690                         key_free(public);
 691                         public = key_new(KEY_UNSPEC);
 692                         if (key_read(public, &kp) != 1) {
 693                                 error("line %d invalid key: %.40s...",
 694                                     num, line);
 695                                 key_free(public);
 696                                 invalid = 1;
 697                                 continue;
 698                         }
 699                 }
 700
 701                 if (*cp == HASH_DELIM) {
 702                         if (find_host || delete_host) {
 703                                 cp2 = host_hash(name, cp, strlen(cp));
 704                                 if (cp2 == NULL) {
 705                                         error("line %d: invalid hashed "
 706                                             "name: %.64s...", num, line);
 707                                         invalid = 1;
 708                                         continue;
 709                                 }
 710                                 c = (strcmp(cp2, cp) == 0);
 711                                 if (find_host && c) {
 712                                         printf("# Host %s found: "
 713                                             "line %d type %s\n", name,
 714                                             num, key_type(public));
 715                                         print_host(out, cp, public, 0);
 716                                 }
 717                                 if (delete_host && !c)
 718                                         print_host(out, cp, public, 0);
 719                         } else if (hash_hosts)
 720                                 print_host(out, cp, public, 0);
 721                 } else {
 722                         if (find_host || delete_host) {
 723                                 c = (match_hostname(name, cp,
 724                                     strlen(cp)) == 1);
 725                                 if (find_host && c) {
 726                                         printf("# Host %s found: "
 727                                             "line %d type %s\n", name,
 728                                             num, key_type(public));
 729                                         print_host(out, cp, public, hash_hosts);
 730                                 }
 731                                 if (delete_host && !c)
 732                                         print_host(out, cp, public, 0);
 733                         } else if (hash_hosts) {
 734                                 for (cp2 = strsep(&cp, ",");
 735                                     cp2 != NULL && *cp2 != '\0';
 736                                     cp2 = strsep(&cp, ",")) {
 737                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 738                                                 fprintf(stderr, "Warning: "
 739                                                     "ignoring host name with "
 740                                                     "metacharacters: %.64s\n",
 741                                                     cp2);
 742                                         else
 743                                                 print_host(out, cp2, public, 1);
 744                                 }
 745                                 has_unhashed = 1;
 746                         }
 747                 }
 748                 key_free(public);
 749         }
 750         fclose(in);
 751
 752         if (invalid) {
 753                 fprintf(stderr, "%s is not a valid known_host file.\n",
 754                     identity_file);
 755                 if (inplace) {
 756                         fprintf(stderr, "Not replacing existing known_hosts "
 757                             "file because of errors\n");
 758                         fclose(out);
 759                         unlink(tmp);
 760                 }
 761                 exit(1);
 762         }
 763
 764         if (inplace) {
 765                 fclose(out);
 766
 767                 /* Backup existing file */
 768                 if (unlink(old) == -1 && errno != ENOENT)
 769                         fatal("unlink %.100s: %s", old, strerror(errno));
 770                 if (link(identity_file, old) == -1)
 771                         fatal("link %.100s to %.100s: %s", identity_file, old,
 772                             strerror(errno));
 773                 /* Move new one into place */
 774                 if (rename(tmp, identity_file) == -1) {
 775                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 776                             strerror(errno));
 777                         unlink(tmp);
 778                         unlink(old);
 779                         exit(1);
 780                 }
 781
 782                 fprintf(stderr, "%s updated.\n", identity_file);
 783                 fprintf(stderr, "Original contents retained as %s\n", old);
 784                 if (has_unhashed) {
 785                         fprintf(stderr, "WARNING: %s contains unhashed "
 786                             "entries\n", old);
 787                         fprintf(stderr, "Delete this file to ensure privacy "
 788                             "of hostnames\n");
 789                 }
 790         }
 791
 792         exit(0);
 793 }
 794
 795 /*
 796  * Perform changing a passphrase.  The argument is the passwd structure
 797  * for the current user.
 798  */
 799 static void
 800 do_change_passphrase(struct passwd *pw)
 801 {
 802         char *comment;
 803         char *old_passphrase, *passphrase1, *passphrase2;
 804         struct stat st;
 805         Key *private;
 806
 807         if (!have_identity)
 808                 ask_filename(pw, "Enter file in which the key is");
 809         if (stat(identity_file, &st) < 0) {
 810                 perror(identity_file);
 811                 exit(1);
 812         }
 813         /* Try to load the file with empty passphrase. */
 814         private = key_load_private(identity_file, "", &comment);
 815         if (private == NULL) {
 816                 if (identity_passphrase)
 817                         old_passphrase = xstrdup(identity_passphrase);
 818                 else
 819                         old_passphrase =
 820                             read_passphrase("Enter old passphrase: ",
 821                             RP_ALLOW_STDIN);
 822                 private = key_load_private(identity_file, old_passphrase,
 823                     &comment);
 824                 memset(old_passphrase, 0, strlen(old_passphrase));
 825                 xfree(old_passphrase);
 826                 if (private == NULL) {
 827                         printf("Bad passphrase.\n");
 828                         exit(1);
 829                 }
 830         }
 831         printf("Key has comment '%s'\n", comment);
 832
 833         /* Ask the new passphrase (twice). */
 834         if (identity_new_passphrase) {
 835                 passphrase1 = xstrdup(identity_new_passphrase);
 836                 passphrase2 = NULL;
 837         } else {
 838                 passphrase1 =
 839                         read_passphrase("Enter new passphrase (empty for no "
 840                             "passphrase): ", RP_ALLOW_STDIN);
 841                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 842                     RP_ALLOW_STDIN);
 843
 844                 /* Verify that they are the same. */
 845                 if (strcmp(passphrase1, passphrase2) != 0) {
 846                         memset(passphrase1, 0, strlen(passphrase1));
 847                         memset(passphrase2, 0, strlen(passphrase2));
 848                         xfree(passphrase1);
 849                         xfree(passphrase2);
 850                         printf("Pass phrases do not match.  Try again.\n");
 851                         exit(1);
 852                 }
 853                 /* Destroy the other copy. */
 854                 memset(passphrase2, 0, strlen(passphrase2));
 855                 xfree(passphrase2);
 856         }
 857
 858         /* Save the file using the new passphrase. */
 859         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 860                 printf("Saving the key failed: %s.\n", identity_file);
 861                 memset(passphrase1, 0, strlen(passphrase1));
 862                 xfree(passphrase1);
 863                 key_free(private);
 864                 xfree(comment);
 865                 exit(1);
 866         }
 867         /* Destroy the passphrase and the copy of the key in memory. */
 868         memset(passphrase1, 0, strlen(passphrase1));
 869         xfree(passphrase1);
 870         key_free(private);               /* Destroys contents */
 871         xfree(comment);
 872
 873         printf("Your identification has been saved with the new passphrase.\n");
 874         exit(0);
 875 }
 876
 877 /*
 878  * Print the SSHFP RR.
 879  */
 880 static int
 881 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 882 {
 883         Key *public;
 884         char *comment = NULL;
 885         struct stat st;
 886
 887         if (fname == NULL)
 888                 ask_filename(pw, "Enter file in which the key is");
 889         if (stat(fname, &st) < 0) {
 890                 if (errno == ENOENT)
 891                         return 0;
 892                 perror(fname);
 893                 exit(1);
 894         }
 895         public = key_load_public(fname, &comment);
 896         if (public != NULL) {
 897                 export_dns_rr(hname, public, stdout, print_generic);
 898                 key_free(public);
 899                 xfree(comment);
 900                 return 1;
 901         }
 902         if (comment)
 903                 xfree(comment);
 904
 905         printf("failed to read v2 public key from %s.\n", fname);
 906         exit(1);
 907 }
 908
 909 /*
 910  * Change the comment of a private key file.
 911  */
 912 static void
 913 do_change_comment(struct passwd *pw)
 914 {
 915         char new_comment[1024], *comment, *passphrase;
 916         Key *private;
 917         Key *public;
 918         struct stat st;
 919         FILE *f;
 920         int fd;
 921
 922         if (!have_identity)
 923                 ask_filename(pw, "Enter file in which the key is");
 924         if (stat(identity_file, &st) < 0) {
 925                 perror(identity_file);
 926                 exit(1);
 927         }
 928         private = key_load_private(identity_file, "", &comment);
 929         if (private == NULL) {
 930                 if (identity_passphrase)
 931                         passphrase = xstrdup(identity_passphrase);
 932                 else if (identity_new_passphrase)
 933                         passphrase = xstrdup(identity_new_passphrase);
 934                 else
 935                         passphrase = read_passphrase("Enter passphrase: ",
 936                             RP_ALLOW_STDIN);
 937                 /* Try to load using the passphrase. */
 938                 private = key_load_private(identity_file, passphrase, &comment);
 939                 if (private == NULL) {
 940                         memset(passphrase, 0, strlen(passphrase));
 941                         xfree(passphrase);
 942                         printf("Bad passphrase.\n");
 943                         exit(1);
 944                 }
 945         } else {
 946                 passphrase = xstrdup("");
 947         }
 948         if (private->type != KEY_RSA1) {
 949                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 950                 key_free(private);
 951                 exit(1);
 952         }
 953         printf("Key now has comment '%s'\n", comment);
 954
 955         if (identity_comment) {
 956                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 957         } else {
 958                 printf("Enter new comment: ");
 959                 fflush(stdout);
 960                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 961                         memset(passphrase, 0, strlen(passphrase));
 962                         key_free(private);
 963                         exit(1);
 964                 }
 965                 if (strchr(new_comment, '\n'))
 966                         *strchr(new_comment, '\n') = 0;
 967         }
 968
 969         /* Save the file using the new passphrase. */
 970         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 971                 printf("Saving the key failed: %s.\n", identity_file);
 972                 memset(passphrase, 0, strlen(passphrase));
 973                 xfree(passphrase);
 974                 key_free(private);
 975                 xfree(comment);
 976                 exit(1);
 977         }
 978         memset(passphrase, 0, strlen(passphrase));
 979         xfree(passphrase);
 980         public = key_from_private(private);
 981         key_free(private);
 982
 983         strlcat(identity_file, ".pub", sizeof(identity_file));
 984         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 985         if (fd == -1) {
 986                 printf("Could not save your public key in %s\n", identity_file);
 987                 exit(1);
 988         }
 989         f = fdopen(fd, "w");
 990         if (f == NULL) {
 991                 printf("fdopen %s failed", identity_file);
 992                 exit(1);
 993         }
 994         if (!key_write(public, f))
 995                 fprintf(stderr, "write key failed");
 996         key_free(public);
 997         fprintf(f, " %s\n", new_comment);
 998         fclose(f);
 999
1000         xfree(comment);
1001
1002         printf("The comment in your key file has been changed.\n");
1003         exit(0);
1004 }
1005
1006 static void
1007 usage(void)
1008 {
1009         fprintf(stderr, "Usage: %s [options]\n", __progname);
1010         fprintf(stderr, "Options:\n");
1011         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1012         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1013         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1014         fprintf(stderr, "  -C comment  Provide new comment.\n");
1015         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1016 #ifdef SMARTCARD
1017         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1018 #endif /* SMARTCARD */
1019         fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
1020         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1021         fprintf(stderr, "  -f filename Filename of the key file.\n");
1022         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1023         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1024         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1025         fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
1026         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1027         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1028         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1029         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1030         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1031         fprintf(stderr, "  -q          Quiet.\n");
1032         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1033         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1034         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1035         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1036         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1037 #ifdef SMARTCARD
1038         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1039 #endif /* SMARTCARD */
1040         fprintf(stderr, "  -v          Verbose.\n");
1041         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1042         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1043
1044         exit(1);
1045 }
1046
1047 /*
1048  * Main program for key management.
1049  */
1050 int
1051 main(int argc, char **argv)
1052 {
1053         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1054         char out_file[MAXPATHLEN], *reader_id = NULL;
1055         char *rr_hostname = NULL;
1056         Key *private, *public;
1057         struct passwd *pw;
1058         struct stat st;
1059         int opt, type, fd, download = 0;
1060         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1061         int do_gen_candidates = 0, do_screen_candidates = 0;
1062         int log_level = SYSLOG_LEVEL_INFO;
1063         BIGNUM *start = NULL;
1064         FILE *f;
1065         const char *errstr;
1066
1067         extern int optind;
1068         extern char *optarg;
1069
1070         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1071         sanitise_stdfd();
1072
1073         __progname = ssh_get_progname(argv[0]);
1074
1075         SSLeay_add_all_algorithms();
1076         log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1077
1078         init_rng();
1079         seed_rng();
1080
1081         /* we need this for the home * directory.  */
1082         pw = getpwuid(getuid());
1083         if (!pw) {
1084                 printf("You don't exist, go away!\n");
1085                 exit(1);
1086         }
1087         if (gethostname(hostname, sizeof(hostname)) < 0) {
1088                 perror("gethostname");
1089                 exit(1);
1090         }
1091
1092         while ((opt = getopt(argc, argv,
1093             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1094                 switch (opt) {
1095                 case 'b':
1096                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1097                         if (errstr)
1098                                 fatal("Bits has bad value %s (%s)",
1099                                         optarg, errstr);
1100                         break;
1101                 case 'F':
1102                         find_host = 1;
1103                         rr_hostname = optarg;
1104                         break;
1105                 case 'H':
1106                         hash_hosts = 1;
1107                         break;
1108                 case 'R':
1109                         delete_host = 1;
1110                         rr_hostname = optarg;
1111                         break;
1112                 case 'l':
1113                         print_fingerprint = 1;
1114                         break;
1115                 case 'B':
1116                         print_bubblebabble = 1;
1117                         break;
1118                 case 'p':
1119                         change_passphrase = 1;
1120                         break;
1121                 case 'c':
1122                         change_comment = 1;
1123                         break;
1124                 case 'f':
1125                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1126                             sizeof(identity_file))
1127                                 fatal("Identity filename too long");
1128                         have_identity = 1;
1129                         break;
1130                 case 'g':
1131                         print_generic = 1;
1132                         break;
1133                 case 'P':
1134                         identity_passphrase = optarg;
1135                         break;
1136                 case 'N':
1137                         identity_new_passphrase = optarg;
1138                         break;
1139                 case 'C':
1140                         identity_comment = optarg;
1141                         break;
1142                 case 'q':
1143                         quiet = 1;
1144                         break;
1145                 case 'e':
1146                 case 'x':
1147                         /* export key */
1148                         convert_to_ssh2 = 1;
1149                         break;
1150                 case 'i':
1151                 case 'X':
1152                         /* import key */
1153                         convert_from_ssh2 = 1;
1154                         break;
1155                 case 'y':
1156                         print_public = 1;
1157                         break;
1158                 case 'd':
1159                         key_type_name = "dsa";
1160                         break;
1161                 case 't':
1162                         key_type_name = optarg;
1163                         break;
1164                 case 'D':
1165                         download = 1;
1166                         /*FALLTHROUGH*/
1167                 case 'U':
1168                         reader_id = optarg;
1169                         break;
1170                 case 'v':
1171                         if (log_level == SYSLOG_LEVEL_INFO)
1172                                 log_level = SYSLOG_LEVEL_DEBUG1;
1173                         else {
1174                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1175                                     log_level < SYSLOG_LEVEL_DEBUG3)
1176                                         log_level++;
1177                         }
1178                         break;
1179                 case 'r':
1180                         rr_hostname = optarg;
1181                         break;
1182                 case 'W':
1183                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1184                             UINT_MAX, &errstr);
1185                         if (errstr)
1186                                 fatal("Desired generator has bad value: %s (%s)",
1187                                         optarg, errstr);
1188                         break;
1189                 case 'a':
1190                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1191                         if (errstr)
1192                                 fatal("Invalid number of trials: %s (%s)",
1193                                         optarg, errstr);
1194                         break;
1195                 case 'M':
1196                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1197                         if (errstr) {
1198                                 fatal("Memory limit is %s: %s", errstr, optarg);
1199                         }
1200                         break;
1201                 case 'G':
1202                         do_gen_candidates = 1;
1203                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1204                             sizeof(out_file))
1205                                 fatal("Output filename too long");
1206                         break;
1207                 case 'T':
1208                         do_screen_candidates = 1;
1209                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1210                             sizeof(out_file))
1211                                 fatal("Output filename too long");
1212                         break;
1213                 case 'S':
1214                         /* XXX - also compare length against bits */
1215                         if (BN_hex2bn(&start, optarg) == 0)
1216                                 fatal("Invalid start point.");
1217                         break;
1218                 case '?':
1219                 default:
1220                         usage();
1221                 }
1222         }
1223
1224         /* reinit */
1225         log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
1226
1227         if (optind < argc) {
1228                 printf("Too many arguments.\n");
1229                 usage();
1230         }
1231         if (change_passphrase && change_comment) {
1232                 printf("Can only have one of -p and -c.\n");
1233                 usage();
1234         }
1235         if (delete_host || hash_hosts || find_host)
1236                 do_known_hosts(pw, rr_hostname);
1237         if (print_fingerprint || print_bubblebabble)
1238                 do_fingerprint(pw);
1239         if (change_passphrase)
1240                 do_change_passphrase(pw);
1241         if (change_comment)
1242                 do_change_comment(pw);
1243         if (convert_to_ssh2)
1244                 do_convert_to_ssh2(pw);
1245         if (convert_from_ssh2)
1246                 do_convert_from_ssh2(pw);
1247         if (print_public)
1248                 do_print_public(pw);
1249         if (rr_hostname != NULL) {
1250                 unsigned int n = 0;
1251
1252                 if (have_identity) {
1253                         n = do_print_resource_record(pw,
1254                             identity_file, rr_hostname);
1255                         if (n == 0) {
1256                                 perror(identity_file);
1257                                 exit(1);
1258                         }
1259                         exit(0);
1260                 } else {
1261
1262                         n += do_print_resource_record(pw,
1263                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1264                         n += do_print_resource_record(pw,
1265                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1266
1267                         if (n == 0)
1268                                 fatal("no keys found.");
1269                         exit(0);
1270                 }
1271         }
1272         if (reader_id != NULL) {
1273 #ifdef SMARTCARD
1274                 if (download)
1275                         do_download(pw, reader_id);
1276                 else
1277                         do_upload(pw, reader_id);
1278 #else /* SMARTCARD */
1279                 fatal("no support for smartcards.");
1280 #endif /* SMARTCARD */
1281         }
1282
1283         if (do_gen_candidates) {
1284                 FILE *out = fopen(out_file, "w");
1285
1286                 if (out == NULL) {
1287                         error("Couldn't open modulus candidate file \"%s\": %s",
1288                             out_file, strerror(errno));
1289                         return (1);
1290                 }
1291                 if (bits == 0)
1292                         bits = DEFAULT_BITS;
1293                 if (gen_candidates(out, memory, bits, start) != 0)
1294                         fatal("modulus candidate generation failed");
1295
1296                 return (0);
1297         }
1298
1299         if (do_screen_candidates) {
1300                 FILE *in;
1301                 FILE *out = fopen(out_file, "w");
1302
1303                 if (have_identity && strcmp(identity_file, "-") != 0) {
1304                         if ((in = fopen(identity_file, "r")) == NULL) {
1305                                 fatal("Couldn't open modulus candidate "
1306                                     "file \"%s\": %s", identity_file,
1307                                     strerror(errno));
1308                         }
1309                 } else
1310                         in = stdin;
1311
1312                 if (out == NULL) {
1313                         fatal("Couldn't open moduli file \"%s\": %s",
1314                             out_file, strerror(errno));
1315                 }
1316                 if (prime_test(in, out, trials, generator_wanted) != 0)
1317                         fatal("modulus screening failed");
1318                 return (0);
1319         }
1320
1321         arc4random_stir();
1322
1323         if (key_type_name == NULL)
1324                 key_type_name = "rsa";
1325
1326         type = key_type_from_name(key_type_name);
1327         if (type == KEY_UNSPEC) {
1328                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1329                 exit(1);
1330         }
1331         if (bits == 0)
1332                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1333         if (type == KEY_DSA && bits != 1024)
1334                 fatal("DSA keys must be 1024 bits");
1335         if (!quiet)
1336                 printf("Generating public/private %s key pair.\n", key_type_name);
1337         private = key_generate(type, bits);
1338         if (private == NULL) {
1339                 fprintf(stderr, "key_generate failed");
1340                 exit(1);
1341         }
1342         public  = key_from_private(private);
1343
1344         if (!have_identity)
1345                 ask_filename(pw, "Enter file in which to save the key");
1346
1347         /* Create ~/.ssh directory if it doesn't already exist. */
1348         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1349         if (strstr(identity_file, dotsshdir) != NULL &&
1350             stat(dotsshdir, &st) < 0) {
1351                 if (mkdir(dotsshdir, 0700) < 0)
1352                         error("Could not create directory '%s'.", dotsshdir);
1353                 else if (!quiet)
1354                         printf("Created directory '%s'.\n", dotsshdir);
1355         }
1356         /* If the file already exists, ask the user to confirm. */
1357         if (stat(identity_file, &st) >= 0) {
1358                 char yesno[3];
1359                 printf("%s already exists.\n", identity_file);
1360                 printf("Overwrite (y/n)? ");
1361                 fflush(stdout);
1362                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1363                         exit(1);
1364                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1365                         exit(1);
1366         }
1367         /* Ask for a passphrase (twice). */
1368         if (identity_passphrase)
1369                 passphrase1 = xstrdup(identity_passphrase);
1370         else if (identity_new_passphrase)
1371                 passphrase1 = xstrdup(identity_new_passphrase);
1372         else {
1373 passphrase_again:
1374                 passphrase1 =
1375                         read_passphrase("Enter passphrase (empty for no "
1376                             "passphrase): ", RP_ALLOW_STDIN);
1377                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1378                     RP_ALLOW_STDIN);
1379                 if (strcmp(passphrase1, passphrase2) != 0) {
1380                         /*
1381                          * The passphrases do not match.  Clear them and
1382                          * retry.
1383                          */
1384                         memset(passphrase1, 0, strlen(passphrase1));
1385                         memset(passphrase2, 0, strlen(passphrase2));
1386                         xfree(passphrase1);
1387                         xfree(passphrase2);
1388                         printf("Passphrases do not match.  Try again.\n");
1389                         goto passphrase_again;
1390                 }
1391                 /* Clear the other copy of the passphrase. */
1392                 memset(passphrase2, 0, strlen(passphrase2));
1393                 xfree(passphrase2);
1394         }
1395
1396         if (identity_comment) {
1397                 strlcpy(comment, identity_comment, sizeof(comment));
1398         } else {
1399                 /* Create default commend field for the passphrase. */
1400                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1401         }
1402
1403         /* Save the key with the given passphrase and comment. */
1404         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1405                 printf("Saving the key failed: %s.\n", identity_file);
1406                 memset(passphrase1, 0, strlen(passphrase1));
1407                 xfree(passphrase1);
1408                 exit(1);
1409         }
1410         /* Clear the passphrase. */
1411         memset(passphrase1, 0, strlen(passphrase1));
1412         xfree(passphrase1);
1413
1414         /* Clear the private key and the random number generator. */
1415         key_free(private);
1416         arc4random_stir();
1417
1418         if (!quiet)
1419                 printf("Your identification has been saved in %s.\n", identity_file);
1420
1421         strlcat(identity_file, ".pub", sizeof(identity_file));
1422         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1423         if (fd == -1) {
1424                 printf("Could not save your public key in %s\n", identity_file);
1425                 exit(1);
1426         }
1427         f = fdopen(fd, "w");
1428         if (f == NULL) {
1429                 printf("fdopen %s failed", identity_file);
1430                 exit(1);
1431         }
1432         if (!key_write(public, f))
1433                 fprintf(stderr, "write key failed");
1434         fprintf(f, " %s\n", comment);
1435         fclose(f);
1436
1437         if (!quiet) {
1438                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1439                 printf("Your public key has been saved in %s.\n",
1440                     identity_file);
1441                 printf("The key fingerprint is:\n");
1442                 printf("%s %s\n", fp, comment);
1443                 xfree(fp);
1444         }
1445
1446         key_free(public);
1447         exit(0);
1448 }