crypto/openssh-4/authfile.c

   1 /* $OpenBSD: authfile.c,v 1.76 2006/08/03 03:34:41 deraadt 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 #include <errno.h>
  51 #include <fcntl.h>
  52 #include <stdarg.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <unistd.h>
  57
  58 #include "xmalloc.h"
  59 #include "cipher.h"
  60 #include "buffer.h"
  61 #include "key.h"
  62 #include "ssh.h"
  63 #include "log.h"
  64 #include "authfile.h"
  65 #include "rsa.h"
  66 #include "misc.h"
  67 #include "atomicio.h"
  68
  69 /* Version identification string for SSH v1 identity files. */
  70 static const char authfile_id_string[] =
  71     "SSH PRIVATE KEY FILE FORMAT 1.1\n";
  72
  73 /*
  74  * Saves the authentication (private) key in a file, encrypting it with
  75  * passphrase.  The identification of the file (lowest 64 bits of n) will
  76  * precede the key to provide identification of the key without needing a
  77  * passphrase.
  78  */
  79
  80 static int
  81 key_save_private_rsa1(Key *key, const char *filename, const char *passphrase,
  82     const char *comment)
  83 {
  84         Buffer buffer, encrypted;
  85         u_char buf[100], *cp;
  86         int fd, i, cipher_num;
  87         CipherContext ciphercontext;
  88         Cipher *cipher;
  89         u_int32_t rnd;
  90
  91         /*
  92          * If the passphrase is empty, use SSH_CIPHER_NONE to ease converting
  93          * to another cipher; otherwise use SSH_AUTHFILE_CIPHER.
  94          */
  95         cipher_num = (strcmp(passphrase, "") == 0) ?
  96             SSH_CIPHER_NONE : SSH_AUTHFILE_CIPHER;
  97         if ((cipher = cipher_by_number(cipher_num)) == NULL)
  98                 fatal("save_private_key_rsa: bad cipher");
  99
 100         /* This buffer is used to built the secret part of the private key. */
 101         buffer_init(&buffer);
 102
 103         /* Put checkbytes for checking passphrase validity. */
 104         rnd = arc4random();
 105         buf[0] = rnd & 0xff;
 106         buf[1] = (rnd >> 8) & 0xff;
 107         buf[2] = buf[0];
 108         buf[3] = buf[1];
 109         buffer_append(&buffer, buf, 4);
 110
 111         /*
 112          * Store the private key (n and e will not be stored because they
 113          * will be stored in plain text, and storing them also in encrypted
 114          * format would just give known plaintext).
 115          */
 116         buffer_put_bignum(&buffer, key->rsa->d);
 117         buffer_put_bignum(&buffer, key->rsa->iqmp);
 118         buffer_put_bignum(&buffer, key->rsa->q);        /* reverse from SSL p */
 119         buffer_put_bignum(&buffer, key->rsa->p);        /* reverse from SSL q */
 120
 121         /* Pad the part to be encrypted until its size is a multiple of 8. */
 122         while (buffer_len(&buffer) % 8 != 0)
 123                 buffer_put_char(&buffer, 0);
 124
 125         /* This buffer will be used to contain the data in the file. */
 126         buffer_init(&encrypted);
 127
 128         /* First store keyfile id string. */
 129         for (i = 0; authfile_id_string[i]; i++)
 130                 buffer_put_char(&encrypted, authfile_id_string[i]);
 131         buffer_put_char(&encrypted, 0);
 132
 133         /* Store cipher type. */
 134         buffer_put_char(&encrypted, cipher_num);
 135         buffer_put_int(&encrypted, 0);  /* For future extension */
 136
 137         /* Store public key.  This will be in plain text. */
 138         buffer_put_int(&encrypted, BN_num_bits(key->rsa->n));
 139         buffer_put_bignum(&encrypted, key->rsa->n);
 140         buffer_put_bignum(&encrypted, key->rsa->e);
 141         buffer_put_cstring(&encrypted, comment);
 142
 143         /* Allocate space for the private part of the key in the buffer. */
 144         cp = buffer_append_space(&encrypted, buffer_len(&buffer));
 145
 146         cipher_set_key_string(&ciphercontext, cipher, passphrase,
 147             CIPHER_ENCRYPT);
 148         cipher_crypt(&ciphercontext, cp,
 149             buffer_ptr(&buffer), buffer_len(&buffer));
 150         cipher_cleanup(&ciphercontext);
 151         memset(&ciphercontext, 0, sizeof(ciphercontext));
 152
 153         /* Destroy temporary data. */
 154         memset(buf, 0, sizeof(buf));
 155         buffer_free(&buffer);
 156
 157         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 158         if (fd < 0) {
 159                 error("open %s failed: %s.", filename, strerror(errno));
 160                 buffer_free(&encrypted);
 161                 return 0;
 162         }
 163         if (atomicio(vwrite, fd, buffer_ptr(&encrypted),
 164             buffer_len(&encrypted)) != buffer_len(&encrypted)) {
 165                 error("write to key file %s failed: %s", filename,
 166                     strerror(errno));
 167                 buffer_free(&encrypted);
 168                 close(fd);
 169                 unlink(filename);
 170                 return 0;
 171         }
 172         close(fd);
 173         buffer_free(&encrypted);
 174         return 1;
 175 }
 176
 177 /* save SSH v2 key in OpenSSL PEM format */
 178 static int
 179 key_save_private_pem(Key *key, const char *filename, const char *_passphrase,
 180     const char *comment)
 181 {
 182         FILE *fp;
 183         int fd;
 184         int success = 0;
 185         int len = strlen(_passphrase);
 186         u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL;
 187         const EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL;
 188
 189         if (len > 0 && len <= 4) {
 190                 error("passphrase too short: have %d bytes, need > 4", len);
 191                 return 0;
 192         }
 193         fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 194         if (fd < 0) {
 195                 error("open %s failed: %s.", filename, strerror(errno));
 196                 return 0;
 197         }
 198         fp = fdopen(fd, "w");
 199         if (fp == NULL) {
 200                 error("fdopen %s failed: %s.", filename, strerror(errno));
 201                 close(fd);
 202                 return 0;
 203         }
 204         switch (key->type) {
 205         case KEY_DSA:
 206                 success = PEM_write_DSAPrivateKey(fp, key->dsa,
 207                     cipher, passphrase, len, NULL, NULL);
 208                 break;
 209         case KEY_RSA:
 210                 success = PEM_write_RSAPrivateKey(fp, key->rsa,
 211                     cipher, passphrase, len, NULL, NULL);
 212                 break;
 213         }
 214         fclose(fp);
 215         return success;
 216 }
 217
 218 int
 219 key_save_private(Key *key, const char *filename, const char *passphrase,
 220     const char *comment)
 221 {
 222         switch (key->type) {
 223         case KEY_RSA1:
 224                 return key_save_private_rsa1(key, filename, passphrase,
 225                     comment);
 226         case KEY_DSA:
 227         case KEY_RSA:
 228                 return key_save_private_pem(key, filename, passphrase,
 229                     comment);
 230         default:
 231                 break;
 232         }
 233         error("key_save_private: cannot save key type %d", key->type);
 234         return 0;
 235 }
 236
 237 /*
 238  * Loads the public part of the ssh v1 key file.  Returns NULL if an error was
 239  * encountered (the file does not exist or is not readable), and the key
 240  * otherwise.
 241  */
 242
 243 static Key *
 244 key_load_public_rsa1(int fd, const char *filename, char **commentp)
 245 {
 246         Buffer buffer;
 247         Key *pub;
 248         struct stat st;
 249         char *cp;
 250         u_int i;
 251         size_t len;
 252
 253         if (fstat(fd, &st) < 0) {
 254                 error("fstat for key file %.200s failed: %.100s",
 255                     filename, strerror(errno));
 256                 return NULL;
 257         }
 258         if (st.st_size > 1*1024*1024) {
 259                 error("key file %.200s too large", filename);
 260                 return NULL;
 261         }
 262         len = (size_t)st.st_size;               /* truncated */
 263
 264         buffer_init(&buffer);
 265         cp = buffer_append_space(&buffer, len);
 266
 267         if (atomicio(read, fd, cp, len) != len) {
 268                 debug("Read from key file %.200s failed: %.100s", filename,
 269                     strerror(errno));
 270                 buffer_free(&buffer);
 271                 return NULL;
 272         }
 273
 274         /* Check that it is at least big enough to contain the ID string. */
 275         if (len < sizeof(authfile_id_string)) {
 276                 debug3("Not a RSA1 key file %.200s.", filename);
 277                 buffer_free(&buffer);
 278                 return NULL;
 279         }
 280         /*
 281          * Make sure it begins with the id string.  Consume the id string
 282          * from the buffer.
 283          */
 284         for (i = 0; i < sizeof(authfile_id_string); i++)
 285                 if (buffer_get_char(&buffer) != authfile_id_string[i]) {
 286                         debug3("Not a RSA1 key file %.200s.", filename);
 287                         buffer_free(&buffer);
 288                         return NULL;
 289                 }
 290         /* Skip cipher type and reserved data. */
 291         (void) buffer_get_char(&buffer);        /* cipher type */
 292         (void) buffer_get_int(&buffer);         /* reserved */
 293
 294         /* Read the public key from the buffer. */
 295         (void) buffer_get_int(&buffer);
 296         pub = key_new(KEY_RSA1);
 297         buffer_get_bignum(&buffer, pub->rsa->n);
 298         buffer_get_bignum(&buffer, pub->rsa->e);
 299         if (commentp)
 300                 *commentp = buffer_get_string(&buffer, NULL);
 301         /* The encrypted private part is not parsed by this function. */
 302
 303         buffer_free(&buffer);
 304         return pub;
 305 }
 306
 307 /* load public key from private-key file, works only for SSH v1 */
 308 Key *
 309 key_load_public_type(int type, const char *filename, char **commentp)
 310 {
 311         Key *pub;
 312         int fd;
 313
 314         if (type == KEY_RSA1) {
 315                 fd = open(filename, O_RDONLY);
 316                 if (fd < 0)
 317                         return NULL;
 318                 pub = key_load_public_rsa1(fd, filename, commentp);
 319                 close(fd);
 320                 return pub;
 321         }
 322         return NULL;
 323 }
 324
 325 /*
 326  * Loads the private key from the file.  Returns 0 if an error is encountered
 327  * (file does not exist or is not readable, or passphrase is bad). This
 328  * initializes the private key.
 329  * Assumes we are called under uid of the owner of the file.
 330  */
 331
 332 static Key *
 333 key_load_private_rsa1(int fd, const char *filename, const char *passphrase,
 334     char **commentp)
 335 {
 336         u_int i;
 337         int check1, check2, cipher_type;
 338         size_t len;
 339         Buffer buffer, decrypted;
 340         u_char *cp;
 341         CipherContext ciphercontext;
 342         Cipher *cipher;
 343         Key *prv = NULL;
 344         struct stat st;
 345
 346         if (fstat(fd, &st) < 0) {
 347                 error("fstat for key file %.200s failed: %.100s",
 348                     filename, strerror(errno));
 349                 close(fd);
 350                 return NULL;
 351         }
 352         if (st.st_size > 1*1024*1024) {
 353                 error("key file %.200s too large", filename);
 354                 close(fd);
 355                 return (NULL);
 356         }
 357         len = (size_t)st.st_size;               /* truncated */
 358
 359         buffer_init(&buffer);
 360         cp = buffer_append_space(&buffer, len);
 361
 362         if (atomicio(read, fd, cp, len) != len) {
 363                 debug("Read from key file %.200s failed: %.100s", filename,
 364                     strerror(errno));
 365                 buffer_free(&buffer);
 366                 close(fd);
 367                 return NULL;
 368         }
 369
 370         /* Check that it is at least big enough to contain the ID string. */
 371         if (len < sizeof(authfile_id_string)) {
 372                 debug3("Not a RSA1 key file %.200s.", filename);
 373                 buffer_free(&buffer);
 374                 close(fd);
 375                 return NULL;
 376         }
 377         /*
 378          * Make sure it begins with the id string.  Consume the id string
 379          * from the buffer.
 380          */
 381         for (i = 0; i < sizeof(authfile_id_string); i++)
 382                 if (buffer_get_char(&buffer) != authfile_id_string[i]) {
 383                         debug3("Not a RSA1 key file %.200s.", filename);
 384                         buffer_free(&buffer);
 385                         close(fd);
 386                         return NULL;
 387                 }
 388
 389         /* Read cipher type. */
 390         cipher_type = buffer_get_char(&buffer);
 391         (void) buffer_get_int(&buffer); /* Reserved data. */
 392
 393         /* Read the public key from the buffer. */
 394         (void) buffer_get_int(&buffer);
 395         prv = key_new_private(KEY_RSA1);
 396
 397         buffer_get_bignum(&buffer, prv->rsa->n);
 398         buffer_get_bignum(&buffer, prv->rsa->e);
 399         if (commentp)
 400                 *commentp = buffer_get_string(&buffer, NULL);
 401         else
 402                 xfree(buffer_get_string(&buffer, NULL));
 403
 404         /* Check that it is a supported cipher. */
 405         cipher = cipher_by_number(cipher_type);
 406         if (cipher == NULL) {
 407                 debug("Unsupported cipher %d used in key file %.200s.",
 408                     cipher_type, filename);
 409                 buffer_free(&buffer);
 410                 goto fail;
 411         }
 412         /* Initialize space for decrypted data. */
 413         buffer_init(&decrypted);
 414         cp = buffer_append_space(&decrypted, buffer_len(&buffer));
 415
 416         /* Rest of the buffer is encrypted.  Decrypt it using the passphrase. */
 417         cipher_set_key_string(&ciphercontext, cipher, passphrase,
 418             CIPHER_DECRYPT);
 419         cipher_crypt(&ciphercontext, cp,
 420             buffer_ptr(&buffer), buffer_len(&buffer));
 421         cipher_cleanup(&ciphercontext);
 422         memset(&ciphercontext, 0, sizeof(ciphercontext));
 423         buffer_free(&buffer);
 424
 425         check1 = buffer_get_char(&decrypted);
 426         check2 = buffer_get_char(&decrypted);
 427         if (check1 != buffer_get_char(&decrypted) ||
 428             check2 != buffer_get_char(&decrypted)) {
 429                 if (strcmp(passphrase, "") != 0)
 430                         debug("Bad passphrase supplied for key file %.200s.",
 431                             filename);
 432                 /* Bad passphrase. */
 433                 buffer_free(&decrypted);
 434                 goto fail;
 435         }
 436         /* Read the rest of the private key. */
 437         buffer_get_bignum(&decrypted, prv->rsa->d);
 438         buffer_get_bignum(&decrypted, prv->rsa->iqmp);          /* u */
 439         /* in SSL and SSH v1 p and q are exchanged */
 440         buffer_get_bignum(&decrypted, prv->rsa->q);             /* p */
 441         buffer_get_bignum(&decrypted, prv->rsa->p);             /* q */
 442
 443         /* calculate p-1 and q-1 */
 444         rsa_generate_additional_parameters(prv->rsa);
 445
 446         buffer_free(&decrypted);
 447
 448         /* enable blinding */
 449         if (RSA_blinding_on(prv->rsa, NULL) != 1) {
 450                 error("key_load_private_rsa1: RSA_blinding_on failed");
 451                 goto fail;
 452         }
 453         close(fd);
 454         return prv;
 455
 456 fail:
 457         if (commentp)
 458                 xfree(*commentp);
 459         close(fd);
 460         key_free(prv);
 461         return NULL;
 462 }
 463
 464 Key *
 465 key_load_private_pem(int fd, int type, const char *passphrase,
 466     char **commentp)
 467 {
 468         FILE *fp;
 469         EVP_PKEY *pk = NULL;
 470         Key *prv = NULL;
 471         char *name = "<no key>";
 472
 473         fp = fdopen(fd, "r");
 474         if (fp == NULL) {
 475                 error("fdopen failed: %s", strerror(errno));
 476                 close(fd);
 477                 return NULL;
 478         }
 479         pk = PEM_read_PrivateKey(fp, NULL, NULL, (char *)passphrase);
 480         if (pk == NULL) {
 481                 debug("PEM_read_PrivateKey failed");
 482                 (void)ERR_get_error();
 483         } else if (pk->type == EVP_PKEY_RSA &&
 484             (type == KEY_UNSPEC||type==KEY_RSA)) {
 485                 prv = key_new(KEY_UNSPEC);
 486                 prv->rsa = EVP_PKEY_get1_RSA(pk);
 487                 prv->type = KEY_RSA;
 488                 name = "rsa w/o comment";
 489 #ifdef DEBUG_PK
 490                 RSA_print_fp(stderr, prv->rsa, 8);
 491 #endif
 492                 if (RSA_blinding_on(prv->rsa, NULL) != 1) {
 493                         error("key_load_private_pem: RSA_blinding_on failed");
 494                         key_free(prv);
 495                         prv = NULL;
 496                 }
 497         } else if (pk->type == EVP_PKEY_DSA &&
 498             (type == KEY_UNSPEC||type==KEY_DSA)) {
 499                 prv = key_new(KEY_UNSPEC);
 500                 prv->dsa = EVP_PKEY_get1_DSA(pk);
 501                 prv->type = KEY_DSA;
 502                 name = "dsa w/o comment";
 503 #ifdef DEBUG_PK
 504                 DSA_print_fp(stderr, prv->dsa, 8);
 505 #endif
 506         } else {
 507                 error("PEM_read_PrivateKey: mismatch or "
 508                     "unknown EVP_PKEY save_type %d", pk->save_type);
 509         }
 510         fclose(fp);
 511         if (pk != NULL)
 512                 EVP_PKEY_free(pk);
 513         if (prv != NULL && commentp)
 514                 *commentp = xstrdup(name);
 515         debug("read PEM private key done: type %s",
 516             prv ? key_type(prv) : "<unknown>");
 517         return prv;
 518 }
 519
 520 int
 521 key_perm_ok(int fd, const char *filename)
 522 {
 523         struct stat st;
 524
 525         if (fstat(fd, &st) < 0)
 526                 return 0;
 527         /*
 528          * if a key owned by the user is accessed, then we check the
 529          * permissions of the file. if the key owned by a different user,
 530          * then we don't care.
 531          */
 532 #ifdef HAVE_CYGWIN
 533         if (check_ntsec(filename))
 534 #endif
 535         if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) {
 536                 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
 537                 error("@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @");
 538                 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
 539                 error("Permissions 0%3.3o for '%s' are too open.",
 540                     (u_int)st.st_mode & 0777, filename);
 541                 error("It is recommended that your private key files are NOT accessible by others.");
 542                 error("This private key will be ignored.");
 543                 return 0;
 544         }
 545         return 1;
 546 }
 547
 548 Key *
 549 key_load_private_type(int type, const char *filename, const char *passphrase,
 550     char **commentp, int *perm_ok)
 551 {
 552         int fd;
 553
 554         fd = open(filename, O_RDONLY);
 555         if (fd < 0)
 556                 return NULL;
 557         if (!key_perm_ok(fd, filename)) {
 558                 if (perm_ok != NULL)
 559                         *perm_ok = 0;
 560                 error("bad permissions: ignore key: %s", filename);
 561                 close(fd);
 562                 return NULL;
 563         }
 564         if (perm_ok != NULL)
 565                 *perm_ok = 1;
 566         switch (type) {
 567         case KEY_RSA1:
 568                 return key_load_private_rsa1(fd, filename, passphrase,
 569                     commentp);
 570                 /* closes fd */
 571         case KEY_DSA:
 572         case KEY_RSA:
 573         case KEY_UNSPEC:
 574                 return key_load_private_pem(fd, type, passphrase, commentp);
 575                 /* closes fd */
 576         default:
 577                 close(fd);
 578                 break;
 579         }
 580         return NULL;
 581 }
 582
 583 Key *
 584 key_load_private(const char *filename, const char *passphrase,
 585     char **commentp)
 586 {
 587         Key *pub, *prv;
 588         int fd;
 589
 590         fd = open(filename, O_RDONLY);
 591         if (fd < 0)
 592                 return NULL;
 593         if (!key_perm_ok(fd, filename)) {
 594                 error("bad permissions: ignore key: %s", filename);
 595                 close(fd);
 596                 return NULL;
 597         }
 598         pub = key_load_public_rsa1(fd, filename, commentp);
 599         lseek(fd, (off_t) 0, SEEK_SET);         /* rewind */
 600         if (pub == NULL) {
 601                 /* closes fd */
 602                 prv = key_load_private_pem(fd, KEY_UNSPEC, passphrase, NULL);
 603                 /* use the filename as a comment for PEM */
 604                 if (commentp && prv)
 605                         *commentp = xstrdup(filename);
 606         } else {
 607                 /* it's a SSH v1 key if the public key part is readable */
 608                 key_free(pub);
 609                 /* closes fd */
 610                 prv = key_load_private_rsa1(fd, filename, passphrase, NULL);
 611         }
 612         return prv;
 613 }
 614
 615 static int
 616 key_try_load_public(Key *k, const char *filename, char **commentp)
 617 {
 618         FILE *f;
 619         char line[SSH_MAX_PUBKEY_BYTES];
 620         char *cp;
 621         u_long linenum = 0;
 622
 623         f = fopen(filename, "r");
 624         if (f != NULL) {
 625                 while (read_keyfile_line(f, filename, line, sizeof(line),
 626                             &linenum) != -1) {
 627                         cp = line;
 628                         switch (*cp) {
 629                         case '#':
 630                         case '\n':
 631                         case '\0':
 632                                 continue;
 633                         }
 634                         /* Skip leading whitespace. */
 635                         for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
 636                                 ;
 637                         if (*cp) {
 638                                 if (key_read(k, &cp) == 1) {
 639                                         if (commentp)
 640                                                 *commentp=xstrdup(filename);
 641                                         fclose(f);
 642                                         return 1;
 643                                 }
 644                         }
 645                 }
 646                 fclose(f);
 647         }
 648         return 0;
 649 }
 650
 651 /* load public key from ssh v1 private or any pubkey file */
 652 Key *
 653 key_load_public(const char *filename, char **commentp)
 654 {
 655         Key *pub;
 656         char file[MAXPATHLEN];
 657
 658         /* try rsa1 private key */
 659         pub = key_load_public_type(KEY_RSA1, filename, commentp);
 660         if (pub != NULL)
 661                 return pub;
 662
 663         /* try rsa1 public key */
 664         pub = key_new(KEY_RSA1);
 665         if (key_try_load_public(pub, filename, commentp) == 1)
 666                 return pub;
 667         key_free(pub);
 668
 669         /* try ssh2 public key */
 670         pub = key_new(KEY_UNSPEC);
 671         if (key_try_load_public(pub, filename, commentp) == 1)
 672                 return pub;
 673         if ((strlcpy(file, filename, sizeof file) < sizeof(file)) &&
 674             (strlcat(file, ".pub", sizeof file) < sizeof(file)) &&
 675             (key_try_load_public(pub, file, commentp) == 1))
 676                 return pub;
 677         key_free(pub);
 678         return NULL;
 679 }