1 /* $OpenBSD: authfile.c,v 1.116 2015/07/09 09:49:46 markus Exp $ */
3 * Copyright (c) 2000, 2013 Markus Friedl. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <sys/types.h>
53 #define MAX_KEY_FILE_SIZE (1024 * 1024)
55 /* Save a key blob to a file */
57 sshkey_save_private_blob(struct sshbuf *keybuf, const char *filename)
61 if ((fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600)) < 0)
62 return SSH_ERR_SYSTEM_ERROR;
63 if (atomicio(vwrite, fd, (u_char *)sshbuf_ptr(keybuf),
64 sshbuf_len(keybuf)) != sshbuf_len(keybuf)) {
69 return SSH_ERR_SYSTEM_ERROR;
76 sshkey_save_private(struct sshkey *key, const char *filename,
77 const char *passphrase, const char *comment,
78 int force_new_format, const char *new_format_cipher, int new_format_rounds)
80 struct sshbuf *keyblob = NULL;
83 if ((keyblob = sshbuf_new()) == NULL)
84 return SSH_ERR_ALLOC_FAIL;
85 if ((r = sshkey_private_to_fileblob(key, keyblob, passphrase, comment,
86 force_new_format, new_format_cipher, new_format_rounds)) != 0)
88 if ((r = sshkey_save_private_blob(keyblob, filename)) != 0)
96 /* Load a key from a fd into a buffer */
98 sshkey_load_file(int fd, struct sshbuf *blob)
105 if (fstat(fd, &st) < 0)
106 return SSH_ERR_SYSTEM_ERROR;
107 if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
108 st.st_size > MAX_KEY_FILE_SIZE)
109 return SSH_ERR_INVALID_FORMAT;
111 if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
114 r = SSH_ERR_SYSTEM_ERROR;
117 if ((r = sshbuf_put(blob, buf, len)) != 0)
119 if (sshbuf_len(blob) > MAX_KEY_FILE_SIZE) {
120 r = SSH_ERR_INVALID_FORMAT;
124 if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
125 st.st_size != (off_t)sshbuf_len(blob)) {
126 r = SSH_ERR_FILE_CHANGED;
132 explicit_bzero(buf, sizeof(buf));
140 * Loads the public part of the ssh v1 key file. Returns NULL if an error was
141 * encountered (the file does not exist or is not readable), and the key
145 sshkey_load_public_rsa1(int fd, struct sshkey **keyp, char **commentp)
147 struct sshbuf *b = NULL;
151 if (commentp != NULL)
154 if ((b = sshbuf_new()) == NULL)
155 return SSH_ERR_ALLOC_FAIL;
156 if ((r = sshkey_load_file(fd, b)) != 0)
158 if ((r = sshkey_parse_public_rsa1_fileblob(b, keyp, commentp)) != 0)
165 #endif /* WITH_SSH1 */
167 /* XXX remove error() calls from here? */
169 sshkey_perm_ok(int fd, const char *filename)
173 if (fstat(fd, &st) < 0)
174 return SSH_ERR_SYSTEM_ERROR;
176 * if a key owned by the user is accessed, then we check the
177 * permissions of the file. if the key owned by a different user,
178 * then we don't care.
181 if (check_ntsec(filename))
183 if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) {
184 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
185 error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
186 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
187 error("Permissions 0%3.3o for '%s' are too open.",
188 (u_int)st.st_mode & 0777, filename);
189 error("It is required that your private key files are NOT accessible by others.");
190 error("This private key will be ignored.");
191 return SSH_ERR_KEY_BAD_PERMISSIONS;
196 /* XXX kill perm_ok now that we have SSH_ERR_KEY_BAD_PERMISSIONS? */
198 sshkey_load_private_type(int type, const char *filename, const char *passphrase,
199 struct sshkey **keyp, char **commentp, int *perm_ok)
204 if (commentp != NULL)
207 if ((fd = open(filename, O_RDONLY)) < 0) {
210 return SSH_ERR_SYSTEM_ERROR;
212 if (sshkey_perm_ok(fd, filename) != 0) {
215 r = SSH_ERR_KEY_BAD_PERMISSIONS;
221 r = sshkey_load_private_type_fd(fd, type, passphrase, keyp, commentp);
228 sshkey_load_private_type_fd(int fd, int type, const char *passphrase,
229 struct sshkey **keyp, char **commentp)
231 struct sshbuf *buffer = NULL;
234 if ((buffer = sshbuf_new()) == NULL) {
235 r = SSH_ERR_ALLOC_FAIL;
238 if ((r = sshkey_load_file(fd, buffer)) != 0 ||
239 (r = sshkey_parse_private_fileblob_type(buffer, type,
240 passphrase, keyp, commentp)) != 0)
251 /* XXX this is almost identical to sshkey_load_private_type() */
253 sshkey_load_private(const char *filename, const char *passphrase,
254 struct sshkey **keyp, char **commentp)
256 struct sshbuf *buffer = NULL;
260 if (commentp != NULL)
263 if ((fd = open(filename, O_RDONLY)) < 0)
264 return SSH_ERR_SYSTEM_ERROR;
265 if (sshkey_perm_ok(fd, filename) != 0) {
266 r = SSH_ERR_KEY_BAD_PERMISSIONS;
270 if ((buffer = sshbuf_new()) == NULL) {
271 r = SSH_ERR_ALLOC_FAIL;
274 if ((r = sshkey_load_file(fd, buffer)) != 0 ||
275 (r = sshkey_parse_private_fileblob(buffer, passphrase, filename,
276 keyp, commentp)) != 0)
287 sshkey_try_load_public(struct sshkey *k, const char *filename, char **commentp)
290 char line[SSH_MAX_PUBKEY_BYTES];
295 if (commentp != NULL)
297 if ((f = fopen(filename, "r")) == NULL)
298 return SSH_ERR_SYSTEM_ERROR;
299 while (read_keyfile_line(f, filename, line, sizeof(line),
308 /* Abort loading if this looks like a private key */
309 if (strncmp(cp, "-----BEGIN", 10) == 0 ||
310 strcmp(cp, "SSH PRIVATE KEY FILE") == 0)
312 /* Skip leading whitespace. */
313 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
316 if ((r = sshkey_read(k, &cp)) == 0) {
317 cp[strcspn(cp, "\r\n")] = '\0';
319 *commentp = strdup(*cp ?
321 if (*commentp == NULL)
322 r = SSH_ERR_ALLOC_FAIL;
330 return SSH_ERR_INVALID_FORMAT;
333 /* load public key from ssh v1 private or any pubkey file */
335 sshkey_load_public(const char *filename, struct sshkey **keyp, char **commentp)
337 struct sshkey *pub = NULL;
343 if (commentp != NULL)
346 /* XXX should load file once and attempt to parse each format */
348 if ((fd = open(filename, O_RDONLY)) < 0)
351 /* try rsa1 private key */
352 r = sshkey_load_public_rsa1(fd, keyp, commentp);
355 case SSH_ERR_INTERNAL_ERROR:
356 case SSH_ERR_ALLOC_FAIL:
357 case SSH_ERR_INVALID_ARGUMENT:
358 case SSH_ERR_SYSTEM_ERROR:
362 #else /* WITH_SSH1 */
364 #endif /* WITH_SSH1 */
366 /* try ssh2 public key */
367 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL)
368 return SSH_ERR_ALLOC_FAIL;
369 if ((r = sshkey_try_load_public(pub, filename, commentp)) == 0) {
377 /* try rsa1 public key */
378 if ((pub = sshkey_new(KEY_RSA1)) == NULL)
379 return SSH_ERR_ALLOC_FAIL;
380 if ((r = sshkey_try_load_public(pub, filename, commentp)) == 0) {
386 #endif /* WITH_SSH1 */
389 /* try .pub suffix */
390 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL)
391 return SSH_ERR_ALLOC_FAIL;
392 r = SSH_ERR_ALLOC_FAIL; /* in case strlcpy or strlcat fail */
393 if ((strlcpy(file, filename, sizeof file) < sizeof(file)) &&
394 (strlcat(file, ".pub", sizeof file) < sizeof(file)) &&
395 (r = sshkey_try_load_public(pub, file, commentp)) == 0) {
405 /* Load the certificate associated with the named private key */
407 sshkey_load_cert(const char *filename, struct sshkey **keyp)
409 struct sshkey *pub = NULL;
411 int r = SSH_ERR_INTERNAL_ERROR;
415 if (asprintf(&file, "%s-cert.pub", filename) == -1)
416 return SSH_ERR_ALLOC_FAIL;
418 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
421 if ((r = sshkey_try_load_public(pub, file, NULL)) != 0)
436 /* Load private key and certificate */
438 sshkey_load_private_cert(int type, const char *filename, const char *passphrase,
439 struct sshkey **keyp, int *perm_ok)
441 struct sshkey *key = NULL, *cert = NULL;
451 #endif /* WITH_OPENSSL */
456 return SSH_ERR_KEY_TYPE_UNKNOWN;
459 if ((r = sshkey_load_private_type(type, filename,
460 passphrase, &key, NULL, perm_ok)) != 0 ||
461 (r = sshkey_load_cert(filename, &cert)) != 0)
464 /* Make sure the private key matches the certificate */
465 if (sshkey_equal_public(key, cert) == 0) {
466 r = SSH_ERR_KEY_CERT_MISMATCH;
470 if ((r = sshkey_to_certified(key)) != 0 ||
471 (r = sshkey_cert_copy(cert, key)) != 0)
485 * Returns success if the specified "key" is listed in the file "filename",
486 * SSH_ERR_KEY_NOT_FOUND: if the key is not listed or another error.
487 * If "strict_type" is set then the key type must match exactly,
488 * otherwise a comparison that ignores certficiate data is performed.
489 * If "check_ca" is set and "key" is a certificate, then its CA key is
490 * also checked and sshkey_in_file() will return success if either is found.
493 sshkey_in_file(struct sshkey *key, const char *filename, int strict_type,
497 char line[SSH_MAX_PUBKEY_BYTES];
501 struct sshkey *pub = NULL;
502 int (*sshkey_compare)(const struct sshkey *, const struct sshkey *) =
503 strict_type ? sshkey_equal : sshkey_equal_public;
505 if ((f = fopen(filename, "r")) == NULL)
506 return SSH_ERR_SYSTEM_ERROR;
508 while (read_keyfile_line(f, filename, line, sizeof(line),
512 /* Skip leading whitespace. */
513 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
516 /* Skip comments and empty lines */
524 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
525 r = SSH_ERR_ALLOC_FAIL;
528 if ((r = sshkey_read(pub, &cp)) != 0)
530 if (sshkey_compare(key, pub) ||
531 (check_ca && sshkey_is_cert(key) &&
532 sshkey_compare(key->cert->signature_key, pub))) {
539 r = SSH_ERR_KEY_NOT_FOUND;
548 * Checks whether the specified key is revoked, returning 0 if not,
549 * SSH_ERR_KEY_REVOKED if it is or another error code if something
550 * unexpected happened.
551 * This will check both the key and, if it is a certificate, its CA key too.
552 * "revoked_keys_file" may be a KRL or a one-per-line list of public keys.
555 sshkey_check_revoked(struct sshkey *key, const char *revoked_keys_file)
559 r = ssh_krl_file_contains_key(revoked_keys_file, key);
560 /* If this was not a KRL to begin with then continue below */
561 if (r != SSH_ERR_KRL_BAD_MAGIC)
565 * If the file is not a KRL or we can't handle KRLs then attempt to
566 * parse the file as a flat list of keys.
568 switch ((r = sshkey_in_file(key, revoked_keys_file, 0, 1))) {
570 /* Key found => revoked */
571 return SSH_ERR_KEY_REVOKED;
572 case SSH_ERR_KEY_NOT_FOUND:
573 /* Key not found => not revoked */
576 /* Some other error occurred */