ssh-keygen.c

   1 /* $OpenBSD: ssh-keygen.c,v 1.155 2006/11/06 21:25:28 markus 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         if (c == EOF)
 350                 return -1;
 351         return pos;
 352 }
 353
 354 static void
 355 do_convert_from_ssh2(struct passwd *pw)
 356 {
 357         Key *k;
 358         int blen;
 359         u_int len;
 360         char line[1024];
 361         u_char blob[8096];
 362         char encoded[8096];
 363         struct stat st;
 364         int escaped = 0, private = 0, ok;
 365         FILE *fp;
 366
 367         if (!have_identity)
 368                 ask_filename(pw, "Enter file in which the key is");
 369         if (stat(identity_file, &st) < 0) {
 370                 perror(identity_file);
 371                 exit(1);
 372         }
 373         fp = fopen(identity_file, "r");
 374         if (fp == NULL) {
 375                 perror(identity_file);
 376                 exit(1);
 377         }
 378         encoded[0] = '\0';
 379         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
 380                 if (line[blen - 1] == '\\')
 381                         escaped++;
 382                 if (strncmp(line, "----", 4) == 0 ||
 383                     strstr(line, ": ") != NULL) {
 384                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 385                                 private = 1;
 386                         if (strstr(line, " END ") != NULL) {
 387                                 break;
 388                         }
 389                         /* fprintf(stderr, "ignore: %s", line); */
 390                         continue;
 391                 }
 392                 if (escaped) {
 393                         escaped--;
 394                         /* fprintf(stderr, "escaped: %s", line); */
 395                         continue;
 396                 }
 397                 strlcat(encoded, line, sizeof(encoded));
 398         }
 399         len = strlen(encoded);
 400         if (((len % 4) == 3) &&
 401             (encoded[len-1] == '=') &&
 402             (encoded[len-2] == '=') &&
 403             (encoded[len-3] == '='))
 404                 encoded[len-3] = '\0';
 405         blen = uudecode(encoded, blob, sizeof(blob));
 406         if (blen < 0) {
 407                 fprintf(stderr, "uudecode failed.\n");
 408                 exit(1);
 409         }
 410         k = private ?
 411             do_convert_private_ssh2_from_blob(blob, blen) :
 412             key_from_blob(blob, blen);
 413         if (k == NULL) {
 414                 fprintf(stderr, "decode blob failed.\n");
 415                 exit(1);
 416         }
 417         ok = private ?
 418             (k->type == KEY_DSA ?
 419                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 420                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 421             key_write(k, stdout);
 422         if (!ok) {
 423                 fprintf(stderr, "key write failed");
 424                 exit(1);
 425         }
 426         key_free(k);
 427         if (!private)
 428                 fprintf(stdout, "\n");
 429         fclose(fp);
 430         exit(0);
 431 }
 432
 433 static void
 434 do_print_public(struct passwd *pw)
 435 {
 436         Key *prv;
 437         struct stat st;
 438
 439         if (!have_identity)
 440                 ask_filename(pw, "Enter file in which the key is");
 441         if (stat(identity_file, &st) < 0) {
 442                 perror(identity_file);
 443                 exit(1);
 444         }
 445         prv = load_identity(identity_file);
 446         if (prv == NULL) {
 447                 fprintf(stderr, "load failed\n");
 448                 exit(1);
 449         }
 450         if (!key_write(prv, stdout))
 451                 fprintf(stderr, "key_write failed");
 452         key_free(prv);
 453         fprintf(stdout, "\n");
 454         exit(0);
 455 }
 456
 457 #ifdef SMARTCARD
 458 static void
 459 do_upload(struct passwd *pw, const char *sc_reader_id)
 460 {
 461         Key *prv = NULL;
 462         struct stat st;
 463         int ret;
 464
 465         if (!have_identity)
 466                 ask_filename(pw, "Enter file in which the key is");
 467         if (stat(identity_file, &st) < 0) {
 468                 perror(identity_file);
 469                 exit(1);
 470         }
 471         prv = load_identity(identity_file);
 472         if (prv == NULL) {
 473                 error("load failed");
 474                 exit(1);
 475         }
 476         ret = sc_put_key(prv, sc_reader_id);
 477         key_free(prv);
 478         if (ret < 0)
 479                 exit(1);
 480         logit("loading key done");
 481         exit(0);
 482 }
 483
 484 static void
 485 do_download(struct passwd *pw, const char *sc_reader_id)
 486 {
 487         Key **keys = NULL;
 488         int i;
 489
 490         keys = sc_get_keys(sc_reader_id, NULL);
 491         if (keys == NULL)
 492                 fatal("cannot read public key from smartcard");
 493         for (i = 0; keys[i]; i++) {
 494                 key_write(keys[i], stdout);
 495                 key_free(keys[i]);
 496                 fprintf(stdout, "\n");
 497         }
 498         xfree(keys);
 499         exit(0);
 500 }
 501 #endif /* SMARTCARD */
 502
 503 static void
 504 do_fingerprint(struct passwd *pw)
 505 {
 506         FILE *f;
 507         Key *public;
 508         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 509         int i, skip = 0, num = 1, invalid = 1;
 510         enum fp_rep rep;
 511         enum fp_type fptype;
 512         struct stat st;
 513
 514         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 515         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 516
 517         if (!have_identity)
 518                 ask_filename(pw, "Enter file in which the key is");
 519         if (stat(identity_file, &st) < 0) {
 520                 perror(identity_file);
 521                 exit(1);
 522         }
 523         public = key_load_public(identity_file, &comment);
 524         if (public != NULL) {
 525                 fp = key_fingerprint(public, fptype, rep);
 526                 printf("%u %s %s\n", key_size(public), fp, comment);
 527                 key_free(public);
 528                 xfree(comment);
 529                 xfree(fp);
 530                 exit(0);
 531         }
 532         if (comment) {
 533                 xfree(comment);
 534                 comment = NULL;
 535         }
 536
 537         f = fopen(identity_file, "r");
 538         if (f != NULL) {
 539                 while (fgets(line, sizeof(line), f)) {
 540                         i = strlen(line) - 1;
 541                         if (line[i] != '\n') {
 542                                 error("line %d too long: %.40s...", num, line);
 543                                 skip = 1;
 544                                 continue;
 545                         }
 546                         num++;
 547                         if (skip) {
 548                                 skip = 0;
 549                                 continue;
 550                         }
 551                         line[i] = '\0';
 552
 553                         /* Skip leading whitespace, empty and comment lines. */
 554                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 555                                 ;
 556                         if (!*cp || *cp == '\n' || *cp == '#')
 557                                 continue ;
 558                         i = strtol(cp, &ep, 10);
 559                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 560                                 int quoted = 0;
 561                                 comment = cp;
 562                                 for (; *cp && (quoted || (*cp != ' ' &&
 563                                     *cp != '\t')); cp++) {
 564                                         if (*cp == '\\' && cp[1] == '"')
 565                                                 cp++;   /* Skip both */
 566                                         else if (*cp == '"')
 567                                                 quoted = !quoted;
 568                                 }
 569                                 if (!*cp)
 570                                         continue;
 571                                 *cp++ = '\0';
 572                         }
 573                         ep = cp;
 574                         public = key_new(KEY_RSA1);
 575                         if (key_read(public, &cp) != 1) {
 576                                 cp = ep;
 577                                 key_free(public);
 578                                 public = key_new(KEY_UNSPEC);
 579                                 if (key_read(public, &cp) != 1) {
 580                                         key_free(public);
 581                                         continue;
 582                                 }
 583                         }
 584                         comment = *cp ? cp : comment;
 585                         fp = key_fingerprint(public, fptype, rep);
 586                         printf("%u %s %s\n", key_size(public), fp,
 587                             comment ? comment : "no comment");
 588                         xfree(fp);
 589                         key_free(public);
 590                         invalid = 0;
 591                 }
 592                 fclose(f);
 593         }
 594         if (invalid) {
 595                 printf("%s is not a public key file.\n", identity_file);
 596                 exit(1);
 597         }
 598         exit(0);
 599 }
 600
 601 static void
 602 print_host(FILE *f, char *name, Key *public, int hash)
 603 {
 604         if (hash && (name = host_hash(name, NULL, 0)) == NULL)
 605                 fatal("hash_host failed");
 606         fprintf(f, "%s ", name);
 607         if (!key_write(public, f))
 608                 fatal("key_write failed");
 609         fprintf(f, "\n");
 610 }
 611
 612 static void
 613 do_known_hosts(struct passwd *pw, const char *name)
 614 {
 615         FILE *in, *out = stdout;
 616         Key *public;
 617         char *cp, *cp2, *kp, *kp2;
 618         char line[16*1024], tmp[MAXPATHLEN], old[MAXPATHLEN];
 619         int c, i, skip = 0, inplace = 0, num = 0, invalid = 0, has_unhashed = 0;
 620
 621         if (!have_identity) {
 622                 cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
 623                 if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
 624                     sizeof(identity_file))
 625                         fatal("Specified known hosts path too long");
 626                 xfree(cp);
 627                 have_identity = 1;
 628         }
 629         if ((in = fopen(identity_file, "r")) == NULL)
 630                 fatal("fopen: %s", strerror(errno));
 631
 632         /*
 633          * Find hosts goes to stdout, hash and deletions happen in-place
 634          * A corner case is ssh-keygen -HF foo, which should go to stdout
 635          */
 636         if (!find_host && (hash_hosts || delete_host)) {
 637                 if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
 638                     strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
 639                     strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
 640                     strlcat(old, ".old", sizeof(old)) >= sizeof(old))
 641                         fatal("known_hosts path too long");
 642                 umask(077);
 643                 if ((c = mkstemp(tmp)) == -1)
 644                         fatal("mkstemp: %s", strerror(errno));
 645                 if ((out = fdopen(c, "w")) == NULL) {
 646                         c = errno;
 647                         unlink(tmp);
 648                         fatal("fdopen: %s", strerror(c));
 649                 }
 650                 inplace = 1;
 651         }
 652
 653         while (fgets(line, sizeof(line), in)) {
 654                 num++;
 655                 i = strlen(line) - 1;
 656                 if (line[i] != '\n') {
 657                         error("line %d too long: %.40s...", num, line);
 658                         skip = 1;
 659                         invalid = 1;
 660                         continue;
 661                 }
 662                 if (skip) {
 663                         skip = 0;
 664                         continue;
 665                 }
 666                 line[i] = '\0';
 667
 668                 /* Skip leading whitespace, empty and comment lines. */
 669                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 670                         ;
 671                 if (!*cp || *cp == '\n' || *cp == '#') {
 672                         if (inplace)
 673                                 fprintf(out, "%s\n", cp);
 674                         continue;
 675                 }
 676                 /* Find the end of the host name portion. */
 677                 for (kp = cp; *kp && *kp != ' ' && *kp != '\t'; kp++)
 678                         ;
 679                 if (*kp == '\0' || *(kp + 1) == '\0') {
 680                         error("line %d missing key: %.40s...",
 681                             num, line);
 682                         invalid = 1;
 683                         continue;
 684                 }
 685                 *kp++ = '\0';
 686                 kp2 = kp;
 687
 688                 public = key_new(KEY_RSA1);
 689                 if (key_read(public, &kp) != 1) {
 690                         kp = kp2;
 691                         key_free(public);
 692                         public = key_new(KEY_UNSPEC);
 693                         if (key_read(public, &kp) != 1) {
 694                                 error("line %d invalid key: %.40s...",
 695                                     num, line);
 696                                 key_free(public);
 697                                 invalid = 1;
 698                                 continue;
 699                         }
 700                 }
 701
 702                 if (*cp == HASH_DELIM) {
 703                         if (find_host || delete_host) {
 704                                 cp2 = host_hash(name, cp, strlen(cp));
 705                                 if (cp2 == NULL) {
 706                                         error("line %d: invalid hashed "
 707                                             "name: %.64s...", num, line);
 708                                         invalid = 1;
 709                                         continue;
 710                                 }
 711                                 c = (strcmp(cp2, cp) == 0);
 712                                 if (find_host && c) {
 713                                         printf("# Host %s found: "
 714                                             "line %d type %s\n", name,
 715                                             num, key_type(public));
 716                                         print_host(out, cp, public, 0);
 717                                 }
 718                                 if (delete_host && !c)
 719                                         print_host(out, cp, public, 0);
 720                         } else if (hash_hosts)
 721                                 print_host(out, cp, public, 0);
 722                 } else {
 723                         if (find_host || delete_host) {
 724                                 c = (match_hostname(name, cp,
 725                                     strlen(cp)) == 1);
 726                                 if (find_host && c) {
 727                                         printf("# Host %s found: "
 728                                             "line %d type %s\n", name,
 729                                             num, key_type(public));
 730                                         print_host(out, cp, public, hash_hosts);
 731                                 }
 732                                 if (delete_host && !c)
 733                                         print_host(out, cp, public, 0);
 734                         } else if (hash_hosts) {
 735                                 for (cp2 = strsep(&cp, ",");
 736                                     cp2 != NULL && *cp2 != '\0';
 737                                     cp2 = strsep(&cp, ",")) {
 738                                         if (strcspn(cp2, "*?!") != strlen(cp2))
 739                                                 fprintf(stderr, "Warning: "
 740                                                     "ignoring host name with "
 741                                                     "metacharacters: %.64s\n",
 742                                                     cp2);
 743                                         else
 744                                                 print_host(out, cp2, public, 1);
 745                                 }
 746                                 has_unhashed = 1;
 747                         }
 748                 }
 749                 key_free(public);
 750         }
 751         fclose(in);
 752
 753         if (invalid) {
 754                 fprintf(stderr, "%s is not a valid known_host file.\n",
 755                     identity_file);
 756                 if (inplace) {
 757                         fprintf(stderr, "Not replacing existing known_hosts "
 758                             "file because of errors\n");
 759                         fclose(out);
 760                         unlink(tmp);
 761                 }
 762                 exit(1);
 763         }
 764
 765         if (inplace) {
 766                 fclose(out);
 767
 768                 /* Backup existing file */
 769                 if (unlink(old) == -1 && errno != ENOENT)
 770                         fatal("unlink %.100s: %s", old, strerror(errno));
 771                 if (link(identity_file, old) == -1)
 772                         fatal("link %.100s to %.100s: %s", identity_file, old,
 773                             strerror(errno));
 774                 /* Move new one into place */
 775                 if (rename(tmp, identity_file) == -1) {
 776                         error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
 777                             strerror(errno));
 778                         unlink(tmp);
 779                         unlink(old);
 780                         exit(1);
 781                 }
 782
 783                 fprintf(stderr, "%s updated.\n", identity_file);
 784                 fprintf(stderr, "Original contents retained as %s\n", old);
 785                 if (has_unhashed) {
 786                         fprintf(stderr, "WARNING: %s contains unhashed "
 787                             "entries\n", old);
 788                         fprintf(stderr, "Delete this file to ensure privacy "
 789                             "of hostnames\n");
 790                 }
 791         }
 792
 793         exit(0);
 794 }
 795
 796 /*
 797  * Perform changing a passphrase.  The argument is the passwd structure
 798  * for the current user.
 799  */
 800 static void
 801 do_change_passphrase(struct passwd *pw)
 802 {
 803         char *comment;
 804         char *old_passphrase, *passphrase1, *passphrase2;
 805         struct stat st;
 806         Key *private;
 807
 808         if (!have_identity)
 809                 ask_filename(pw, "Enter file in which the key is");
 810         if (stat(identity_file, &st) < 0) {
 811                 perror(identity_file);
 812                 exit(1);
 813         }
 814         /* Try to load the file with empty passphrase. */
 815         private = key_load_private(identity_file, "", &comment);
 816         if (private == NULL) {
 817                 if (identity_passphrase)
 818                         old_passphrase = xstrdup(identity_passphrase);
 819                 else
 820                         old_passphrase =
 821                             read_passphrase("Enter old passphrase: ",
 822                             RP_ALLOW_STDIN);
 823                 private = key_load_private(identity_file, old_passphrase,
 824                     &comment);
 825                 memset(old_passphrase, 0, strlen(old_passphrase));
 826                 xfree(old_passphrase);
 827                 if (private == NULL) {
 828                         printf("Bad passphrase.\n");
 829                         exit(1);
 830                 }
 831         }
 832         printf("Key has comment '%s'\n", comment);
 833
 834         /* Ask the new passphrase (twice). */
 835         if (identity_new_passphrase) {
 836                 passphrase1 = xstrdup(identity_new_passphrase);
 837                 passphrase2 = NULL;
 838         } else {
 839                 passphrase1 =
 840                         read_passphrase("Enter new passphrase (empty for no "
 841                             "passphrase): ", RP_ALLOW_STDIN);
 842                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 843                     RP_ALLOW_STDIN);
 844
 845                 /* Verify that they are the same. */
 846                 if (strcmp(passphrase1, passphrase2) != 0) {
 847                         memset(passphrase1, 0, strlen(passphrase1));
 848                         memset(passphrase2, 0, strlen(passphrase2));
 849                         xfree(passphrase1);
 850                         xfree(passphrase2);
 851                         printf("Pass phrases do not match.  Try again.\n");
 852                         exit(1);
 853                 }
 854                 /* Destroy the other copy. */
 855                 memset(passphrase2, 0, strlen(passphrase2));
 856                 xfree(passphrase2);
 857         }
 858
 859         /* Save the file using the new passphrase. */
 860         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 861                 printf("Saving the key failed: %s.\n", identity_file);
 862                 memset(passphrase1, 0, strlen(passphrase1));
 863                 xfree(passphrase1);
 864                 key_free(private);
 865                 xfree(comment);
 866                 exit(1);
 867         }
 868         /* Destroy the passphrase and the copy of the key in memory. */
 869         memset(passphrase1, 0, strlen(passphrase1));
 870         xfree(passphrase1);
 871         key_free(private);               /* Destroys contents */
 872         xfree(comment);
 873
 874         printf("Your identification has been saved with the new passphrase.\n");
 875         exit(0);
 876 }
 877
 878 /*
 879  * Print the SSHFP RR.
 880  */
 881 static int
 882 do_print_resource_record(struct passwd *pw, char *fname, char *hname)
 883 {
 884         Key *public;
 885         char *comment = NULL;
 886         struct stat st;
 887
 888         if (fname == NULL)
 889                 ask_filename(pw, "Enter file in which the key is");
 890         if (stat(fname, &st) < 0) {
 891                 if (errno == ENOENT)
 892                         return 0;
 893                 perror(fname);
 894                 exit(1);
 895         }
 896         public = key_load_public(fname, &comment);
 897         if (public != NULL) {
 898                 export_dns_rr(hname, public, stdout, print_generic);
 899                 key_free(public);
 900                 xfree(comment);
 901                 return 1;
 902         }
 903         if (comment)
 904                 xfree(comment);
 905
 906         printf("failed to read v2 public key from %s.\n", fname);
 907         exit(1);
 908 }
 909
 910 /*
 911  * Change the comment of a private key file.
 912  */
 913 static void
 914 do_change_comment(struct passwd *pw)
 915 {
 916         char new_comment[1024], *comment, *passphrase;
 917         Key *private;
 918         Key *public;
 919         struct stat st;
 920         FILE *f;
 921         int fd;
 922
 923         if (!have_identity)
 924                 ask_filename(pw, "Enter file in which the key is");
 925         if (stat(identity_file, &st) < 0) {
 926                 perror(identity_file);
 927                 exit(1);
 928         }
 929         private = key_load_private(identity_file, "", &comment);
 930         if (private == NULL) {
 931                 if (identity_passphrase)
 932                         passphrase = xstrdup(identity_passphrase);
 933                 else if (identity_new_passphrase)
 934                         passphrase = xstrdup(identity_new_passphrase);
 935                 else
 936                         passphrase = read_passphrase("Enter passphrase: ",
 937                             RP_ALLOW_STDIN);
 938                 /* Try to load using the passphrase. */
 939                 private = key_load_private(identity_file, passphrase, &comment);
 940                 if (private == NULL) {
 941                         memset(passphrase, 0, strlen(passphrase));
 942                         xfree(passphrase);
 943                         printf("Bad passphrase.\n");
 944                         exit(1);
 945                 }
 946         } else {
 947                 passphrase = xstrdup("");
 948         }
 949         if (private->type != KEY_RSA1) {
 950                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 951                 key_free(private);
 952                 exit(1);
 953         }
 954         printf("Key now has comment '%s'\n", comment);
 955
 956         if (identity_comment) {
 957                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 958         } else {
 959                 printf("Enter new comment: ");
 960                 fflush(stdout);
 961                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 962                         memset(passphrase, 0, strlen(passphrase));
 963                         key_free(private);
 964                         exit(1);
 965                 }
 966                 if (strchr(new_comment, '\n'))
 967                         *strchr(new_comment, '\n') = 0;
 968         }
 969
 970         /* Save the file using the new passphrase. */
 971         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 972                 printf("Saving the key failed: %s.\n", identity_file);
 973                 memset(passphrase, 0, strlen(passphrase));
 974                 xfree(passphrase);
 975                 key_free(private);
 976                 xfree(comment);
 977                 exit(1);
 978         }
 979         memset(passphrase, 0, strlen(passphrase));
 980         xfree(passphrase);
 981         public = key_from_private(private);
 982         key_free(private);
 983
 984         strlcat(identity_file, ".pub", sizeof(identity_file));
 985         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 986         if (fd == -1) {
 987                 printf("Could not save your public key in %s\n", identity_file);
 988                 exit(1);
 989         }
 990         f = fdopen(fd, "w");
 991         if (f == NULL) {
 992                 printf("fdopen %s failed", identity_file);
 993                 exit(1);
 994         }
 995         if (!key_write(public, f))
 996                 fprintf(stderr, "write key failed");
 997         key_free(public);
 998         fprintf(f, " %s\n", new_comment);
 999         fclose(f);
1000
1001         xfree(comment);
1002
1003         printf("The comment in your key file has been changed.\n");
1004         exit(0);
1005 }
1006
1007 static void
1008 usage(void)
1009 {
1010         fprintf(stderr, "Usage: %s [options]\n", __progname);
1011         fprintf(stderr, "Options:\n");
1012         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
1013         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
1014         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
1015         fprintf(stderr, "  -C comment  Provide new comment.\n");
1016         fprintf(stderr, "  -c          Change comment in private and public key files.\n");
1017 #ifdef SMARTCARD
1018         fprintf(stderr, "  -D reader   Download public key from smartcard.\n");
1019 #endif /* SMARTCARD */
1020         fprintf(stderr, "  -e          Convert OpenSSH to IETF SECSH key file.\n");
1021         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
1022         fprintf(stderr, "  -f filename Filename of the key file.\n");
1023         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
1024         fprintf(stderr, "  -g          Use generic DNS resource record format.\n");
1025         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
1026         fprintf(stderr, "  -i          Convert IETF SECSH to OpenSSH key file.\n");
1027         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
1028         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
1029         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
1030         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
1031         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
1032         fprintf(stderr, "  -q          Quiet.\n");
1033         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
1034         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
1035         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
1036         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
1037         fprintf(stderr, "  -t type     Specify type of key to create.\n");
1038 #ifdef SMARTCARD
1039         fprintf(stderr, "  -U reader   Upload private key to smartcard.\n");
1040 #endif /* SMARTCARD */
1041         fprintf(stderr, "  -v          Verbose.\n");
1042         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
1043         fprintf(stderr, "  -y          Read private key file and print public key.\n");
1044
1045         exit(1);
1046 }
1047
1048 /*
1049  * Main program for key management.
1050  */
1051 int
1052 main(int ac, char **av)
1053 {
1054         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
1055         char out_file[MAXPATHLEN], *reader_id = NULL;
1056         char *rr_hostname = NULL;
1057         Key *private, *public;
1058         struct passwd *pw;
1059         struct stat st;
1060         int opt, type, fd, download = 0;
1061         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
1062         int do_gen_candidates = 0, do_screen_candidates = 0;
1063         int log_level = SYSLOG_LEVEL_INFO;
1064         BIGNUM *start = NULL;
1065         FILE *f;
1066         const char *errstr;
1067
1068         extern int optind;
1069         extern char *optarg;
1070
1071         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1072         sanitise_stdfd();
1073
1074         __progname = ssh_get_progname(av[0]);
1075
1076         SSLeay_add_all_algorithms();
1077         log_init(av[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
1078
1079         init_rng();
1080         seed_rng();
1081
1082         /* we need this for the home * directory.  */
1083         pw = getpwuid(getuid());
1084         if (!pw) {
1085                 printf("You don't exist, go away!\n");
1086                 exit(1);
1087         }
1088         if (gethostname(hostname, sizeof(hostname)) < 0) {
1089                 perror("gethostname");
1090                 exit(1);
1091         }
1092
1093         while ((opt = getopt(ac, av,
1094             "degiqpclBHvxXyF:b:f:t:U:D:P:N:C:r:g:R:T:G:M:S:a:W:")) != -1) {
1095                 switch (opt) {
1096                 case 'b':
1097                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
1098                         if (errstr)
1099                                 fatal("Bits has bad value %s (%s)",
1100                                         optarg, errstr);
1101                         break;
1102                 case 'F':
1103                         find_host = 1;
1104                         rr_hostname = optarg;
1105                         break;
1106                 case 'H':
1107                         hash_hosts = 1;
1108                         break;
1109                 case 'R':
1110                         delete_host = 1;
1111                         rr_hostname = optarg;
1112                         break;
1113                 case 'l':
1114                         print_fingerprint = 1;
1115                         break;
1116                 case 'B':
1117                         print_bubblebabble = 1;
1118                         break;
1119                 case 'p':
1120                         change_passphrase = 1;
1121                         break;
1122                 case 'c':
1123                         change_comment = 1;
1124                         break;
1125                 case 'f':
1126                         if (strlcpy(identity_file, optarg, sizeof(identity_file)) >=
1127                             sizeof(identity_file))
1128                                 fatal("Identity filename too long");
1129                         have_identity = 1;
1130                         break;
1131                 case 'g':
1132                         print_generic = 1;
1133                         break;
1134                 case 'P':
1135                         identity_passphrase = optarg;
1136                         break;
1137                 case 'N':
1138                         identity_new_passphrase = optarg;
1139                         break;
1140                 case 'C':
1141                         identity_comment = optarg;
1142                         break;
1143                 case 'q':
1144                         quiet = 1;
1145                         break;
1146                 case 'e':
1147                 case 'x':
1148                         /* export key */
1149                         convert_to_ssh2 = 1;
1150                         break;
1151                 case 'i':
1152                 case 'X':
1153                         /* import key */
1154                         convert_from_ssh2 = 1;
1155                         break;
1156                 case 'y':
1157                         print_public = 1;
1158                         break;
1159                 case 'd':
1160                         key_type_name = "dsa";
1161                         break;
1162                 case 't':
1163                         key_type_name = optarg;
1164                         break;
1165                 case 'D':
1166                         download = 1;
1167                         /*FALLTHROUGH*/
1168                 case 'U':
1169                         reader_id = optarg;
1170                         break;
1171                 case 'v':
1172                         if (log_level == SYSLOG_LEVEL_INFO)
1173                                 log_level = SYSLOG_LEVEL_DEBUG1;
1174                         else {
1175                                 if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
1176                                     log_level < SYSLOG_LEVEL_DEBUG3)
1177                                         log_level++;
1178                         }
1179                         break;
1180                 case 'r':
1181                         rr_hostname = optarg;
1182                         break;
1183                 case 'W':
1184                         generator_wanted = (u_int32_t)strtonum(optarg, 1,
1185                             UINT_MAX, &errstr);
1186                         if (errstr)
1187                                 fatal("Desired generator has bad value: %s (%s)",
1188                                         optarg, errstr);
1189                         break;
1190                 case 'a':
1191                         trials = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1192                         if (errstr)
1193                                 fatal("Invalid number of trials: %s (%s)",
1194                                         optarg, errstr);
1195                         break;
1196                 case 'M':
1197                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
1198                         if (errstr) {
1199                                 fatal("Memory limit is %s: %s", errstr, optarg);
1200                         }
1201                         break;
1202                 case 'G':
1203                         do_gen_candidates = 1;
1204                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1205                             sizeof(out_file))
1206                                 fatal("Output filename too long");
1207                         break;
1208                 case 'T':
1209                         do_screen_candidates = 1;
1210                         if (strlcpy(out_file, optarg, sizeof(out_file)) >=
1211                             sizeof(out_file))
1212                                 fatal("Output filename too long");
1213                         break;
1214                 case 'S':
1215                         /* XXX - also compare length against bits */
1216                         if (BN_hex2bn(&start, optarg) == 0)
1217                                 fatal("Invalid start point.");
1218                         break;
1219                 case '?':
1220                 default:
1221                         usage();
1222                 }
1223         }
1224
1225         /* reinit */
1226         log_init(av[0], log_level, SYSLOG_FACILITY_USER, 1);
1227
1228         if (optind < ac) {
1229                 printf("Too many arguments.\n");
1230                 usage();
1231         }
1232         if (change_passphrase && change_comment) {
1233                 printf("Can only have one of -p and -c.\n");
1234                 usage();
1235         }
1236         if (delete_host || hash_hosts || find_host)
1237                 do_known_hosts(pw, rr_hostname);
1238         if (print_fingerprint || print_bubblebabble)
1239                 do_fingerprint(pw);
1240         if (change_passphrase)
1241                 do_change_passphrase(pw);
1242         if (change_comment)
1243                 do_change_comment(pw);
1244         if (convert_to_ssh2)
1245                 do_convert_to_ssh2(pw);
1246         if (convert_from_ssh2)
1247                 do_convert_from_ssh2(pw);
1248         if (print_public)
1249                 do_print_public(pw);
1250         if (rr_hostname != NULL) {
1251                 unsigned int n = 0;
1252
1253                 if (have_identity) {
1254                         n = do_print_resource_record(pw,
1255                             identity_file, rr_hostname);
1256                         if (n == 0) {
1257                                 perror(identity_file);
1258                                 exit(1);
1259                         }
1260                         exit(0);
1261                 } else {
1262
1263                         n += do_print_resource_record(pw,
1264                             _PATH_HOST_RSA_KEY_FILE, rr_hostname);
1265                         n += do_print_resource_record(pw,
1266                             _PATH_HOST_DSA_KEY_FILE, rr_hostname);
1267
1268                         if (n == 0)
1269                                 fatal("no keys found.");
1270                         exit(0);
1271                 }
1272         }
1273         if (reader_id != NULL) {
1274 #ifdef SMARTCARD
1275                 if (download)
1276                         do_download(pw, reader_id);
1277                 else
1278                         do_upload(pw, reader_id);
1279 #else /* SMARTCARD */
1280                 fatal("no support for smartcards.");
1281 #endif /* SMARTCARD */
1282         }
1283
1284         if (do_gen_candidates) {
1285                 FILE *out = fopen(out_file, "w");
1286
1287                 if (out == NULL) {
1288                         error("Couldn't open modulus candidate file \"%s\": %s",
1289                             out_file, strerror(errno));
1290                         return (1);
1291                 }
1292                 if (bits == 0)
1293                         bits = DEFAULT_BITS;
1294                 if (gen_candidates(out, memory, bits, start) != 0)
1295                         fatal("modulus candidate generation failed");
1296
1297                 return (0);
1298         }
1299
1300         if (do_screen_candidates) {
1301                 FILE *in;
1302                 FILE *out = fopen(out_file, "w");
1303
1304                 if (have_identity && strcmp(identity_file, "-") != 0) {
1305                         if ((in = fopen(identity_file, "r")) == NULL) {
1306                                 fatal("Couldn't open modulus candidate "
1307                                     "file \"%s\": %s", identity_file,
1308                                     strerror(errno));
1309                         }
1310                 } else
1311                         in = stdin;
1312
1313                 if (out == NULL) {
1314                         fatal("Couldn't open moduli file \"%s\": %s",
1315                             out_file, strerror(errno));
1316                 }
1317                 if (prime_test(in, out, trials, generator_wanted) != 0)
1318                         fatal("modulus screening failed");
1319                 return (0);
1320         }
1321
1322         arc4random_stir();
1323
1324         if (key_type_name == NULL)
1325                 key_type_name = "rsa";
1326
1327         type = key_type_from_name(key_type_name);
1328         if (type == KEY_UNSPEC) {
1329                 fprintf(stderr, "unknown key type %s\n", key_type_name);
1330                 exit(1);
1331         }
1332         if (bits == 0)
1333                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
1334         if (type == KEY_DSA && bits != 1024)
1335                 fatal("DSA keys must be 1024 bits");
1336         if (!quiet)
1337                 printf("Generating public/private %s key pair.\n", key_type_name);
1338         private = key_generate(type, bits);
1339         if (private == NULL) {
1340                 fprintf(stderr, "key_generate failed");
1341                 exit(1);
1342         }
1343         public  = key_from_private(private);
1344
1345         if (!have_identity)
1346                 ask_filename(pw, "Enter file in which to save the key");
1347
1348         /* Create ~/.ssh directory if it doesn't already exist. */
1349         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
1350         if (strstr(identity_file, dotsshdir) != NULL &&
1351             stat(dotsshdir, &st) < 0) {
1352                 if (mkdir(dotsshdir, 0700) < 0)
1353                         error("Could not create directory '%s'.", dotsshdir);
1354                 else if (!quiet)
1355                         printf("Created directory '%s'.\n", dotsshdir);
1356         }
1357         /* If the file already exists, ask the user to confirm. */
1358         if (stat(identity_file, &st) >= 0) {
1359                 char yesno[3];
1360                 printf("%s already exists.\n", identity_file);
1361                 printf("Overwrite (y/n)? ");
1362                 fflush(stdout);
1363                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
1364                         exit(1);
1365                 if (yesno[0] != 'y' && yesno[0] != 'Y')
1366                         exit(1);
1367         }
1368         /* Ask for a passphrase (twice). */
1369         if (identity_passphrase)
1370                 passphrase1 = xstrdup(identity_passphrase);
1371         else if (identity_new_passphrase)
1372                 passphrase1 = xstrdup(identity_new_passphrase);
1373         else {
1374 passphrase_again:
1375                 passphrase1 =
1376                         read_passphrase("Enter passphrase (empty for no "
1377                             "passphrase): ", RP_ALLOW_STDIN);
1378                 passphrase2 = read_passphrase("Enter same passphrase again: ",
1379                     RP_ALLOW_STDIN);
1380                 if (strcmp(passphrase1, passphrase2) != 0) {
1381                         /*
1382                          * The passphrases do not match.  Clear them and
1383                          * retry.
1384                          */
1385                         memset(passphrase1, 0, strlen(passphrase1));
1386                         memset(passphrase2, 0, strlen(passphrase2));
1387                         xfree(passphrase1);
1388                         xfree(passphrase2);
1389                         printf("Passphrases do not match.  Try again.\n");
1390                         goto passphrase_again;
1391                 }
1392                 /* Clear the other copy of the passphrase. */
1393                 memset(passphrase2, 0, strlen(passphrase2));
1394                 xfree(passphrase2);
1395         }
1396
1397         if (identity_comment) {
1398                 strlcpy(comment, identity_comment, sizeof(comment));
1399         } else {
1400                 /* Create default commend field for the passphrase. */
1401                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
1402         }
1403
1404         /* Save the key with the given passphrase and comment. */
1405         if (!key_save_private(private, identity_file, passphrase1, comment)) {
1406                 printf("Saving the key failed: %s.\n", identity_file);
1407                 memset(passphrase1, 0, strlen(passphrase1));
1408                 xfree(passphrase1);
1409                 exit(1);
1410         }
1411         /* Clear the passphrase. */
1412         memset(passphrase1, 0, strlen(passphrase1));
1413         xfree(passphrase1);
1414
1415         /* Clear the private key and the random number generator. */
1416         key_free(private);
1417         arc4random_stir();
1418
1419         if (!quiet)
1420                 printf("Your identification has been saved in %s.\n", identity_file);
1421
1422         strlcat(identity_file, ".pub", sizeof(identity_file));
1423         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
1424         if (fd == -1) {
1425                 printf("Could not save your public key in %s\n", identity_file);
1426                 exit(1);
1427         }
1428         f = fdopen(fd, "w");
1429         if (f == NULL) {
1430                 printf("fdopen %s failed", identity_file);
1431                 exit(1);
1432         }
1433         if (!key_write(public, f))
1434                 fprintf(stderr, "write key failed");
1435         fprintf(f, " %s\n", comment);
1436         fclose(f);
1437
1438         if (!quiet) {
1439                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
1440                 printf("Your public key has been saved in %s.\n",
1441                     identity_file);
1442                 printf("The key fingerprint is:\n");
1443                 printf("%s %s\n", fp, comment);
1444                 xfree(fp);
1445         }
1446
1447         key_free(public);
1448         exit(0);
1449 }