authfile.c

   1 /* $OpenBSD: authfile.c,v 1.77 2009/10/22 22:26:13 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * This file contains functions for reading and writing identity files, and
   7  * for reading the passphrase from the user.
   8  *
   9  * As far as I am concerned, the code I have written for this software
  10  * can be used freely for any purpose.  Any derived versions of this
  11  * software must be clearly marked as such, and if the derived work is
  12  * incompatible with the protocol description in the RFC file, it must be
  13  * called by a name other than "ssh" or "Secure Shell".
  14  *
  15  *
  16  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions
  20  * are met:
  21  * 1. Redistributions of source code must retain the above copyright
  22  *    notice, this list of conditions and the following disclaimer.
  23  * 2. Redistributions in binary form must reproduce the above copyright
  24  *    notice, this list of conditions and the following disclaimer in the
  25  *    documentation and/or other materials provided with the distribution.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  28  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  29  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  30  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  31  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  32  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  33  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  34  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  36  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 #include "includes.h"
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <sys/param.h>
  44 #include <sys/uio.h>
  45
  46 #include <openssl/err.h>
  47 #include <openssl/evp.h>
  48 #include <openssl/pem.h>
  49
  50 /* compatibility with old or broken OpenSSL versions */
  51 #include "openbsd-compat/openssl-compat.h"
  52
  53 #include <errno.h>
  54 #include <fcntl.h>
  55 #include <stdarg.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include <unistd.h>
  60
  61 #include "xmalloc.h"
  62 #include "cipher.h"
  63 #include "buffer.h"
  64 #include "key.h"
  65 #include "ssh.h"
  66 #include "log.h"
  67 #include "authfile.h"
  68 #include "rsa.h"
  69 #include "misc.h"
  70 #include "atomicio.h"
  71
  72 /* Version identification string for SSH v1 identity files. */
  73 static const char authfile_id_string[] =
  74     "SSH PRIVATE KEY FILE FORMAT 1.1\n";
  75
  76 /*
  77  * Saves the authentication (private) key in a file, encrypting it with
  78  * passphrase.  The identification of the file (lowest 64 bits of n) will
  79  * precede the key to provide identification of the key without needing a
  80  * passphrase.
  81  */
  82
  83 static int
  84 key_save_private_rsa1(Key *key, const char *filename, const char *passphrase,
  85     const char *comment)
  86 {
  87         Buffer buffer, encrypted;
  88         u_char buf[100], *cp;
  89         int fd, i, cipher_num;
  90         CipherContext ciphercontext;
  91         Cipher *cipher;
  92         u_int32_t rnd;
  93
  94         /*
  95          * If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
  96          * to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
  97          */
  98         cipher_num = (strcmp(passphrase, "") == 0) ?
  99             SSH_CIPHER_NONE : SSH_AUTHFILE_CIPHER;
 100         if ((cipher = cipher_by_number(cipher_num)) == NULL)
 101                 fatal("save_private_key_rsa: bad cipher");
 102
 103         /* This buffer is used to built the secret part of the private key. */
 104         buffer_init(&buffer);
 105
 106         /* Put checkbytes for checking passphrase validity. */
 107         rnd = arc4random();
 108         buf[0] = rnd & 0xff;
 109         buf[1] = (rnd >> 8) & 0xff;
 110         buf[2] = buf[0];
 111         buf[3] = buf[1];
 112         buffer_append(&buffer, buf, 4);
 113
 114         /*
 115          * Store the private key (n and e will not be stored because they
 116          * will be stored in plain text, and storing them also in encrypted
 117          * format would just give known plaintext).
 118          */
 119         buffer_put_bignum(&buffer, key->rsa->d);
 120         buffer_put_bignum(&buffer, key->rsa->iqmp);
 121         buffer_put_bignum(&buffer, key->rsa->q);        /* reverse from SSL p */
 122         buffer_put_bignum(&buffer, key->rsa->p);        /* reverse from SSL q */
 123
 124         /* Pad the part to be encrypted until its size is a multiple of 8. */
 125         while (buffer_len(&buffer) % 8 != 0)
 126                 buffer_put_char(&buffer, 0);
 127
 128         /* This buffer will be used to contain the data in the file. */
 129         buffer_init(&encrypted);
 130
 131         /* First store keyfile id string. */
 132         for (i = 0; authfile_id_string[i]; i++)
 133                 buffer_put_char(&encrypted, authfile_id_string[i]);
 134         buffer_put_char(&encrypted, 0);
 135
 136         /* Store cipher type. */
 137         buffer_put_char(&encrypted, cipher_num);
 138         buffer_put_int(&encrypted, 0);  /* For future extension */
 139
 140         /* Store public key.  This will be in plain text. */
 141         buffer_put_int(&encrypted, BN_num_bits(key->rsa->n));
 142         buffer_put_bignum(&encrypted, key->rsa->n);
 143         buffer_put_bignum(&encrypted, key->rsa->e);
 144         buffer_put_cstring(&encrypted, comment);
 145
 146         /* Allocate space for the private part of the key in the buffer. */
 147         cp = buffer_append_space(&encrypted, buffer_len(&buffer));
 148
 149         cipher_set_key_string(&ciphercontext, cipher, passphrase,
 150             CIPHER_ENCRYPT);
 151         cipher_crypt(&ciphercontext, cp,
 152             buffer_ptr(&buffer), buffer_len(&buffer));
 153         cipher_cleanup(&ciphercontext);
 154         memset(&ciphercontext, 0, sizeof(ciphercontext));
 155
 156         /* Destroy temporary data. */
 157         memset(buf, 0, sizeof(buf));
 158         buffer_free(&buffer);
 159
 160         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 161         if (fd < 0) {
 162                 error("open %s failed: %s.", filename, strerror(errno));
 163                 buffer_free(&encrypted);
 164                 return 0;
 165         }
 166         if (atomicio(vwrite, fd, buffer_ptr(&encrypted),
 167             buffer_len(&encrypted)) != buffer_len(&encrypted)) {
 168                 error("write to key file %s failed: %s", filename,
 169                     strerror(errno));
 170                 buffer_free(&encrypted);
 171                 close(fd);
 172                 unlink(filename);
 173                 return 0;
 174         }
 175         close(fd);
 176         buffer_free(&encrypted);
 177         return 1;
 178 }
 179
 180 /* save SSH v2 key in OpenSSL PEM format */
 181 static int
 182 key_save_private_pem(Key *key, const char *filename, const char *_passphrase,
 183     const char *comment)
 184 {
 185         FILE *fp;
 186         int fd;
 187         int success = 0;
 188         int len = strlen(_passphrase);
 189         u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL;
 190         const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL;
 191
 192         if (len > 0 && len <= 4) {
 193                 error("passphrase too short: have %d bytes, need > 4", len);
 194                 return 0;
 195         }
 196         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 197         if (fd < 0) {
 198                 error("open %s failed: %s.", filename, strerror(errno));
 199                 return 0;
 200         }
 201         fp = fdopen(fd, "w");
 202         if (fp == NULL) {
 203                 error("fdopen %s failed: %s.", filename, strerror(errno));
 204                 close(fd);
 205                 return 0;
 206         }
 207         switch (key->type) {
 208         case KEY_DSA:
 209                 success = PEM_write_DSAPrivateKey(fp, key->dsa,
 210                     cipher, passphrase, len, NULL, NULL);
 211                 break;
 212         case KEY_RSA:
 213                 success = PEM_write_RSAPrivateKey(fp, key->rsa,
 214                     cipher, passphrase, len, NULL, NULL);
 215                 break;
 216         }
 217         fclose(fp);
 218         return success;
 219 }
 220
 221 int
 222 key_save_private(Key *key, const char *filename, const char *passphrase,
 223     const char *comment)
 224 {
 225         switch (key->type) {
 226         case KEY_RSA1:
 227                 return key_save_private_rsa1(key, filename, passphrase,
 228                     comment);
 229         case KEY_DSA:
 230         case KEY_RSA:
 231                 return key_save_private_pem(key, filename, passphrase,
 232                     comment);
 233         default:
 234                 break;
 235         }
 236         error("key_save_private: cannot save key type %d", key->type);
 237         return 0;
 238 }
 239
 240 /*
 241  * Loads the public part of the ssh v1 key file.  Returns NULL if an error was
 242  * encountered (the file does not exist or is not readable), and the key
 243  * otherwise.
 244  */
 245
 246 static Key *
 247 key_load_public_rsa1(int fd, const char *filename, char **commentp)
 248 {
 249         Buffer buffer;
 250         Key *pub;
 251         struct stat st;
 252         char *cp;
 253         u_int i;
 254         size_t len;
 255
 256         if (fstat(fd, &st) < 0) {
 257                 error("fstat for key file %.200s failed: %.100s",
 258                     filename, strerror(errno));
 259                 return NULL;
 260         }
 261         if (st.st_size > 1*1024*1024) {
 262                 error("key file %.200s too large", filename);
 263                 return NULL;
 264         }
 265         len = (size_t)st.st_size;               /* truncated */
 266
 267         buffer_init(&buffer);
 268         cp = buffer_append_space(&buffer, len);
 269
 270         if (atomicio(read, fd, cp, len) != len) {
 271                 debug("Read from key file %.200s failed: %.100s", filename,
 272                     strerror(errno));
 273                 buffer_free(&buffer);
 274                 return NULL;
 275         }
 276
 277         /* Check that it is at least big enough to contain the ID string. */
 278         if (len < sizeof(authfile_id_string)) {
 279                 debug3("Not a RSA1 key file %.200s.", filename);
 280                 buffer_free(&buffer);
 281                 return NULL;
 282         }
 283         /*
 284          * Make sure it begins with the id string.  Consume the id string
 285          * from the buffer.
 286          */
 287         for (i = 0; i < sizeof(authfile_id_string); i++)
 288                 if (buffer_get_char(&buffer) != authfile_id_string[i]) {
 289                         debug3("Not a RSA1 key file %.200s.", filename);
 290                         buffer_free(&buffer);
 291                         return NULL;
 292                 }
 293         /* Skip cipher type and reserved data. */
 294         (void) buffer_get_char(&buffer);        /* cipher type */
 295         (void) buffer_get_int(&buffer);         /* reserved */
 296
 297         /* Read the public key from the buffer. */
 298         (void) buffer_get_int(&buffer);
 299         pub = key_new(KEY_RSA1);
 300         buffer_get_bignum(&buffer, pub->rsa->n);
 301         buffer_get_bignum(&buffer, pub->rsa->e);
 302         if (commentp)
 303                 *commentp = buffer_get_string(&buffer, NULL);
 304         /* The encrypted private part is not parsed by this function. */
 305
 306         buffer_free(&buffer);
 307         return pub;
 308 }
 309
 310 /* load public key from private-key file, works only for SSH v1 */
 311 Key *
 312 key_load_public_type(int type, const char *filename, char **commentp)
 313 {
 314         Key *pub;
 315         int fd;
 316
 317         if (type == KEY_RSA1) {
 318                 fd = open(filename, O_RDONLY);
 319                 if (fd < 0)
 320                         return NULL;
 321                 pub = key_load_public_rsa1(fd, filename, commentp);
 322                 close(fd);
 323                 return pub;
 324         }
 325         return NULL;
 326 }
 327
 328 /*
 329  * Loads the private key from the file.  Returns 0 if an error is encountered
 330  * (file does not exist or is not readable, or passphrase is bad). This
 331  * initializes the private key.
 332  * Assumes we are called under uid of the owner of the file.
 333  */
 334
 335 static Key *
 336 key_load_private_rsa1(int fd, const char *filename, const char *passphrase,
 337     char **commentp)
 338 {
 339         u_int i;
 340         int check1, check2, cipher_type;
 341         size_t len;
 342         Buffer buffer, decrypted;
 343         u_char *cp;
 344         CipherContext ciphercontext;
 345         Cipher *cipher;
 346         Key *prv = NULL;
 347         struct stat st;
 348
 349         if (fstat(fd, &st) < 0) {
 350                 error("fstat for key file %.200s failed: %.100s",
 351                     filename, strerror(errno));
 352                 close(fd);
 353                 return NULL;
 354         }
 355         if (st.st_size > 1*1024*1024) {
 356                 error("key file %.200s too large", filename);
 357                 close(fd);
 358                 return (NULL);
 359         }
 360         len = (size_t)st.st_size;               /* truncated */
 361
 362         buffer_init(&buffer);
 363         cp = buffer_append_space(&buffer, len);
 364
 365         if (atomicio(read, fd, cp, len) != len) {
 366                 debug("Read from key file %.200s failed: %.100s", filename,
 367                     strerror(errno));
 368                 buffer_free(&buffer);
 369                 close(fd);
 370                 return NULL;
 371         }
 372
 373         /* Check that it is at least big enough to contain the ID string. */
 374         if (len < sizeof(authfile_id_string)) {
 375                 debug3("Not a RSA1 key file %.200s.", filename);
 376                 buffer_free(&buffer);
 377                 close(fd);
 378                 return NULL;
 379         }
 380         /*
 381          * Make sure it begins with the id string.  Consume the id string
 382          * from the buffer.
 383          */
 384         for (i = 0; i < sizeof(authfile_id_string); i++)
 385                 if (buffer_get_char(&buffer) != authfile_id_string[i]) {
 386                         debug3("Not a RSA1 key file %.200s.", filename);
 387                         buffer_free(&buffer);
 388                         close(fd);
 389                         return NULL;
 390                 }
 391
 392         /* Read cipher type. */
 393         cipher_type = buffer_get_char(&buffer);
 394         (void) buffer_get_int(&buffer); /* Reserved data. */
 395
 396         /* Read the public key from the buffer. */
 397         (void) buffer_get_int(&buffer);
 398         prv = key_new_private(KEY_RSA1);
 399
 400         buffer_get_bignum(&buffer, prv->rsa->n);
 401         buffer_get_bignum(&buffer, prv->rsa->e);
 402         if (commentp)
 403                 *commentp = buffer_get_string(&buffer, NULL);
 404         else
 405                 xfree(buffer_get_string(&buffer, NULL));
 406
 407         /* Check that it is a supported cipher. */
 408         cipher = cipher_by_number(cipher_type);
 409         if (cipher == NULL) {
 410                 debug("Unsupported cipher %d used in key file %.200s.",
 411                     cipher_type, filename);
 412                 buffer_free(&buffer);
 413                 goto fail;
 414         }
 415         /* Initialize space for decrypted data. */
 416         buffer_init(&decrypted);
 417         cp = buffer_append_space(&decrypted, buffer_len(&buffer));
 418
 419         /* Rest of the buffer is encrypted.  Decrypt it using the passphrase. */
 420         cipher_set_key_string(&ciphercontext, cipher, passphrase,
 421             CIPHER_DECRYPT);
 422         cipher_crypt(&ciphercontext, cp,
 423             buffer_ptr(&buffer), buffer_len(&buffer));
 424         cipher_cleanup(&ciphercontext);
 425         memset(&ciphercontext, 0, sizeof(ciphercontext));
 426         buffer_free(&buffer);
 427
 428         check1 = buffer_get_char(&decrypted);
 429         check2 = buffer_get_char(&decrypted);
 430         if (check1 != buffer_get_char(&decrypted) ||
 431             check2 != buffer_get_char(&decrypted)) {
 432                 if (strcmp(passphrase, "") != 0)
 433                         debug("Bad passphrase supplied for key file %.200s.",
 434                             filename);
 435                 /* Bad passphrase. */
 436                 buffer_free(&decrypted);
 437                 goto fail;
 438         }
 439         /* Read the rest of the private key. */
 440         buffer_get_bignum(&decrypted, prv->rsa->d);
 441         buffer_get_bignum(&decrypted, prv->rsa->iqmp);          /* u */
 442         /* in SSL and SSH v1 p and q are exchanged */
 443         buffer_get_bignum(&decrypted, prv->rsa->q);             /* p */
 444         buffer_get_bignum(&decrypted, prv->rsa->p);             /* q */
 445
 446         /* calculate p-1 and q-1 */
 447         rsa_generate_additional_parameters(prv->rsa);
 448
 449         buffer_free(&decrypted);
 450
 451         /* enable blinding */
 452         if (RSA_blinding_on(prv->rsa, NULL) != 1) {
 453                 error("key_load_private_rsa1: RSA_blinding_on failed");
 454                 goto fail;
 455         }
 456         close(fd);
 457         return prv;
 458
 459 fail:
 460         if (commentp)
 461                 xfree(*commentp);
 462         close(fd);
 463         key_free(prv);
 464         return NULL;
 465 }
 466
 467 Key *
 468 key_load_private_pem(int fd, int type, const char *passphrase,
 469     char **commentp)
 470 {
 471         FILE *fp;
 472         EVP_PKEY *pk = NULL;
 473         Key *prv = NULL;
 474         char *name = "<no key>";
 475
 476         fp = fdopen(fd, "r");
 477         if (fp == NULL) {
 478                 error("fdopen failed: %s", strerror(errno));
 479                 close(fd);
 480                 return NULL;
 481         }
 482         pk = PEM_read_PrivateKey(fp, NULL, NULL, (char *)passphrase);
 483         if (pk == NULL) {
 484                 debug("PEM_read_PrivateKey failed");
 485                 (void)ERR_get_error();
 486         } else if (pk->type == EVP_PKEY_RSA &&
 487             (type == KEY_UNSPEC||type==KEY_RSA)) {
 488                 prv = key_new(KEY_UNSPEC);
 489                 prv->rsa = EVP_PKEY_get1_RSA(pk);
 490                 prv->type = KEY_RSA;
 491                 name = "rsa w/o comment";
 492 #ifdef DEBUG_PK
 493                 RSA_print_fp(stderr, prv->rsa, 8);
 494 #endif
 495                 if (RSA_blinding_on(prv->rsa, NULL) != 1) {
 496                         error("key_load_private_pem: RSA_blinding_on failed");
 497                         key_free(prv);
 498                         prv = NULL;
 499                 }
 500         } else if (pk->type == EVP_PKEY_DSA &&
 501             (type == KEY_UNSPEC||type==KEY_DSA)) {
 502                 prv = key_new(KEY_UNSPEC);
 503                 prv->dsa = EVP_PKEY_get1_DSA(pk);
 504                 prv->type = KEY_DSA;
 505                 name = "dsa w/o comment";
 506 #ifdef DEBUG_PK
 507                 DSA_print_fp(stderr, prv->dsa, 8);
 508 #endif
 509         } else {
 510                 error("PEM_read_PrivateKey: mismatch or "
 511                     "unknown EVP_PKEY save_type %d", pk->save_type);
 512         }
 513         fclose(fp);
 514         if (pk != NULL)
 515                 EVP_PKEY_free(pk);
 516         if (prv != NULL && commentp)
 517                 *commentp = xstrdup(name);
 518         debug("read PEM private key done: type %s",
 519             prv ? key_type(prv) : "<unknown>");
 520         return prv;
 521 }
 522
 523 int
 524 key_perm_ok(int fd, const char *filename)
 525 {
 526         struct stat st;
 527
 528         if (fstat(fd, &st) < 0)
 529                 return 0;
 530         /*
 531          * if a key owned by the user is accessed, then we check the
 532          * permissions of the file. if the key owned by a different user,
 533          * then we don't care.
 534          */
 535 #ifdef HAVE_CYGWIN
 536         if (check_ntsec(filename))
 537 #endif
 538         if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) {
 539                 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
 540                 error("@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @");
 541                 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
 542                 error("Permissions 0%3.3o for '%s' are too open.",
 543                     (u_int)st.st_mode & 0777, filename);
 544                 error("It is recommended that your private key files are NOT accessible by others.");
 545                 error("This private key will be ignored.");
 546                 return 0;
 547         }
 548         return 1;
 549 }
 550
 551 Key *
 552 key_load_private_type(int type, const char *filename, const char *passphrase,
 553     char **commentp, int *perm_ok)
 554 {
 555         int fd;
 556
 557         fd = open(filename, O_RDONLY);
 558         if (fd < 0)
 559                 return NULL;
 560         if (!key_perm_ok(fd, filename)) {
 561                 if (perm_ok != NULL)
 562                         *perm_ok = 0;
 563                 error("bad permissions: ignore key: %s", filename);
 564                 close(fd);
 565                 return NULL;
 566         }
 567         if (perm_ok != NULL)
 568                 *perm_ok = 1;
 569         switch (type) {
 570         case KEY_RSA1:
 571                 return key_load_private_rsa1(fd, filename, passphrase,
 572                     commentp);
 573                 /* closes fd */
 574         case KEY_DSA:
 575         case KEY_RSA:
 576         case KEY_UNSPEC:
 577                 return key_load_private_pem(fd, type, passphrase, commentp);
 578                 /* closes fd */
 579         default:
 580                 close(fd);
 581                 break;
 582         }
 583         return NULL;
 584 }
 585
 586 Key *
 587 key_load_private(const char *filename, const char *passphrase,
 588     char **commentp)
 589 {
 590         Key *pub, *prv;
 591         int fd;
 592
 593         fd = open(filename, O_RDONLY);
 594         if (fd < 0)
 595                 return NULL;
 596         if (!key_perm_ok(fd, filename)) {
 597                 error("bad permissions: ignore key: %s", filename);
 598                 close(fd);
 599                 return NULL;
 600         }
 601         pub = key_load_public_rsa1(fd, filename, commentp);
 602         lseek(fd, (off_t) 0, SEEK_SET);         /* rewind */
 603         if (pub == NULL) {
 604                 /* closes fd */
 605                 prv = key_load_private_pem(fd, KEY_UNSPEC, passphrase, NULL);
 606                 /* use the filename as a comment for PEM */
 607                 if (commentp && prv)
 608                         *commentp = xstrdup(filename);
 609         } else {
 610                 /* it's a SSH v1 key if the public key part is readable */
 611                 key_free(pub);
 612                 /* closes fd */
 613                 prv = key_load_private_rsa1(fd, filename, passphrase, NULL);
 614         }
 615         return prv;
 616 }
 617
 618 static int
 619 key_try_load_public(Key *k, const char *filename, char **commentp)
 620 {
 621         FILE *f;
 622         char line[SSH_MAX_PUBKEY_BYTES];
 623         char *cp;
 624         u_long linenum = 0;
 625
 626         f = fopen(filename, "r");
 627         if (f != NULL) {
 628                 while (read_keyfile_line(f, filename, line, sizeof(line),
 629                             &linenum) != -1) {
 630                         cp = line;
 631                         switch (*cp) {
 632                         case '#':
 633                         case '\n':
 634                         case '\0':
 635                                 continue;
 636                         }
 637                         /* Skip leading whitespace. */
 638                         for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
 639                                 ;
 640                         if (*cp) {
 641                                 if (key_read(k, &cp) == 1) {
 642                                         if (commentp)
 643                                                 *commentp=xstrdup(filename);
 644                                         fclose(f);
 645                                         return 1;
 646                                 }
 647                         }
 648                 }
 649                 fclose(f);
 650         }
 651         return 0;
 652 }
 653
 654 /* load public key from ssh v1 private or any pubkey file */
 655 Key *
 656 key_load_public(const char *filename, char **commentp)
 657 {
 658         Key *pub;
 659         char file[MAXPATHLEN];
 660
 661         /* try rsa1 private key */
 662         pub = key_load_public_type(KEY_RSA1, filename, commentp);
 663         if (pub != NULL)
 664                 return pub;
 665
 666         /* try rsa1 public key */
 667         pub = key_new(KEY_RSA1);
 668         if (key_try_load_public(pub, filename, commentp) == 1)
 669                 return pub;
 670         key_free(pub);
 671
 672         /* try ssh2 public key */
 673         pub = key_new(KEY_UNSPEC);
 674         if (key_try_load_public(pub, filename, commentp) == 1)
 675                 return pub;
 676         if ((strlcpy(file, filename, sizeof file) < sizeof(file)) &&
 677             (strlcat(file, ".pub", sizeof file) < sizeof(file)) &&
 678             (key_try_load_public(pub, file, commentp) == 1))
 679                 return pub;
 680         key_free(pub);
 681         return NULL;
 682 }