1 /* $OpenBSD: authfile.c,v 1.131 2018/09/21 12:20:12 djm 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>
52 #define MAX_KEY_FILE_SIZE (1024 * 1024)
54 /* Save a key blob to a file */
56 sshkey_save_private_blob(struct sshbuf *keybuf, const char *filename)
60 if ((fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600)) < 0)
61 return SSH_ERR_SYSTEM_ERROR;
62 if (atomicio(vwrite, fd, sshbuf_mutable_ptr(keybuf),
63 sshbuf_len(keybuf)) != sshbuf_len(keybuf)) {
68 return SSH_ERR_SYSTEM_ERROR;
75 sshkey_save_private(struct sshkey *key, const char *filename,
76 const char *passphrase, const char *comment,
77 int force_new_format, const char *new_format_cipher, int new_format_rounds)
79 struct sshbuf *keyblob = NULL;
82 if ((keyblob = sshbuf_new()) == NULL)
83 return SSH_ERR_ALLOC_FAIL;
84 if ((r = sshkey_private_to_fileblob(key, keyblob, passphrase, comment,
85 force_new_format, new_format_cipher, new_format_rounds)) != 0)
87 if ((r = sshkey_save_private_blob(keyblob, filename)) != 0)
95 /* Load a key from a fd into a buffer */
97 sshkey_load_file(int fd, struct sshbuf *blob)
104 if (fstat(fd, &st) < 0)
105 return SSH_ERR_SYSTEM_ERROR;
106 if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
107 st.st_size > MAX_KEY_FILE_SIZE)
108 return SSH_ERR_INVALID_FORMAT;
110 if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
113 r = SSH_ERR_SYSTEM_ERROR;
116 if ((r = sshbuf_put(blob, buf, len)) != 0)
118 if (sshbuf_len(blob) > MAX_KEY_FILE_SIZE) {
119 r = SSH_ERR_INVALID_FORMAT;
123 if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
124 st.st_size != (off_t)sshbuf_len(blob)) {
125 r = SSH_ERR_FILE_CHANGED;
131 explicit_bzero(buf, sizeof(buf));
138 /* XXX remove error() calls from here? */
140 sshkey_perm_ok(int fd, const char *filename)
144 if (fstat(fd, &st) < 0)
145 return SSH_ERR_SYSTEM_ERROR;
147 * if a key owned by the user is accessed, then we check the
148 * permissions of the file. if the key owned by a different user,
149 * then we don't care.
152 if (check_ntsec(filename))
154 if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) {
155 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
156 error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
157 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
158 error("Permissions 0%3.3o for '%s' are too open.",
159 (u_int)st.st_mode & 0777, filename);
160 error("It is required that your private key files are NOT accessible by others.");
161 error("This private key will be ignored.");
162 return SSH_ERR_KEY_BAD_PERMISSIONS;
167 /* XXX kill perm_ok now that we have SSH_ERR_KEY_BAD_PERMISSIONS? */
169 sshkey_load_private_type(int type, const char *filename, const char *passphrase,
170 struct sshkey **keyp, char **commentp, int *perm_ok)
176 if (commentp != NULL)
179 if ((fd = open(filename, O_RDONLY)) < 0) {
182 return SSH_ERR_SYSTEM_ERROR;
184 if (sshkey_perm_ok(fd, filename) != 0) {
187 r = SSH_ERR_KEY_BAD_PERMISSIONS;
193 r = sshkey_load_private_type_fd(fd, type, passphrase, keyp, commentp);
194 if (r == 0 && keyp && *keyp)
195 r = sshkey_set_filename(*keyp, filename);
202 sshkey_load_private_type_fd(int fd, int type, const char *passphrase,
203 struct sshkey **keyp, char **commentp)
205 struct sshbuf *buffer = NULL;
210 if ((buffer = sshbuf_new()) == NULL) {
211 r = SSH_ERR_ALLOC_FAIL;
214 if ((r = sshkey_load_file(fd, buffer)) != 0 ||
215 (r = sshkey_parse_private_fileblob_type(buffer, type,
216 passphrase, keyp, commentp)) != 0)
226 /* XXX this is almost identical to sshkey_load_private_type() */
228 sshkey_load_private(const char *filename, const char *passphrase,
229 struct sshkey **keyp, char **commentp)
231 struct sshbuf *buffer = NULL;
236 if (commentp != NULL)
239 if ((fd = open(filename, O_RDONLY)) < 0)
240 return SSH_ERR_SYSTEM_ERROR;
241 if (sshkey_perm_ok(fd, filename) != 0) {
242 r = SSH_ERR_KEY_BAD_PERMISSIONS;
246 if ((buffer = sshbuf_new()) == NULL) {
247 r = SSH_ERR_ALLOC_FAIL;
250 if ((r = sshkey_load_file(fd, buffer)) != 0 ||
251 (r = sshkey_parse_private_fileblob(buffer, passphrase, keyp,
255 (r = sshkey_set_filename(*keyp, filename)) != 0)
265 sshkey_try_load_public(struct sshkey *k, const char *filename, char **commentp)
268 char *line = NULL, *cp;
272 if (commentp != NULL)
274 if ((f = fopen(filename, "r")) == NULL)
275 return SSH_ERR_SYSTEM_ERROR;
276 while (getline(&line, &linesize, f) != -1) {
284 /* Abort loading if this looks like a private key */
285 if (strncmp(cp, "-----BEGIN", 10) == 0 ||
286 strcmp(cp, "SSH PRIVATE KEY FILE") == 0)
288 /* Skip leading whitespace. */
289 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
292 if ((r = sshkey_read(k, &cp)) == 0) {
293 cp[strcspn(cp, "\r\n")] = '\0';
295 *commentp = strdup(*cp ?
297 if (*commentp == NULL)
298 r = SSH_ERR_ALLOC_FAIL;
308 return SSH_ERR_INVALID_FORMAT;
311 /* load public key from any pubkey file */
313 sshkey_load_public(const char *filename, struct sshkey **keyp, char **commentp)
315 struct sshkey *pub = NULL;
321 if (commentp != NULL)
324 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL)
325 return SSH_ERR_ALLOC_FAIL;
326 if ((r = sshkey_try_load_public(pub, filename, commentp)) == 0) {
336 /* try .pub suffix */
337 if (asprintf(&file, "%s.pub", filename) == -1)
338 return SSH_ERR_ALLOC_FAIL;
339 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
340 r = SSH_ERR_ALLOC_FAIL;
343 if ((r = sshkey_try_load_public(pub, file, commentp)) == 0) {
356 /* Load the certificate associated with the named private key */
358 sshkey_load_cert(const char *filename, struct sshkey **keyp)
360 struct sshkey *pub = NULL;
362 int r = SSH_ERR_INTERNAL_ERROR;
367 if (asprintf(&file, "%s-cert.pub", filename) == -1)
368 return SSH_ERR_ALLOC_FAIL;
370 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
373 if ((r = sshkey_try_load_public(pub, file, NULL)) != 0)
387 /* Load private key and certificate */
389 sshkey_load_private_cert(int type, const char *filename, const char *passphrase,
390 struct sshkey **keyp, int *perm_ok)
392 struct sshkey *key = NULL, *cert = NULL;
403 #endif /* WITH_OPENSSL */
409 return SSH_ERR_KEY_TYPE_UNKNOWN;
412 if ((r = sshkey_load_private_type(type, filename,
413 passphrase, &key, NULL, perm_ok)) != 0 ||
414 (r = sshkey_load_cert(filename, &cert)) != 0)
417 /* Make sure the private key matches the certificate */
418 if (sshkey_equal_public(key, cert) == 0) {
419 r = SSH_ERR_KEY_CERT_MISMATCH;
423 if ((r = sshkey_to_certified(key)) != 0 ||
424 (r = sshkey_cert_copy(cert, key)) != 0)
438 * Returns success if the specified "key" is listed in the file "filename",
439 * SSH_ERR_KEY_NOT_FOUND: if the key is not listed or another error.
440 * If "strict_type" is set then the key type must match exactly,
441 * otherwise a comparison that ignores certficiate data is performed.
442 * If "check_ca" is set and "key" is a certificate, then its CA key is
443 * also checked and sshkey_in_file() will return success if either is found.
446 sshkey_in_file(struct sshkey *key, const char *filename, int strict_type,
450 char *line = NULL, *cp;
453 struct sshkey *pub = NULL;
455 int (*sshkey_compare)(const struct sshkey *, const struct sshkey *) =
456 strict_type ? sshkey_equal : sshkey_equal_public;
458 if ((f = fopen(filename, "r")) == NULL)
459 return SSH_ERR_SYSTEM_ERROR;
461 while (getline(&line, &linesize, f) != -1) {
466 /* Skip leading whitespace. */
467 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
470 /* Skip comments and empty lines */
478 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
479 r = SSH_ERR_ALLOC_FAIL;
482 switch (r = sshkey_read(pub, &cp)) {
485 case SSH_ERR_KEY_LENGTH:
490 if (sshkey_compare(key, pub) ||
491 (check_ca && sshkey_is_cert(key) &&
492 sshkey_compare(key->cert->signature_key, pub))) {
497 r = SSH_ERR_KEY_NOT_FOUND;
506 * Checks whether the specified key is revoked, returning 0 if not,
507 * SSH_ERR_KEY_REVOKED if it is or another error code if something
508 * unexpected happened.
509 * This will check both the key and, if it is a certificate, its CA key too.
510 * "revoked_keys_file" may be a KRL or a one-per-line list of public keys.
513 sshkey_check_revoked(struct sshkey *key, const char *revoked_keys_file)
517 r = ssh_krl_file_contains_key(revoked_keys_file, key);
518 /* If this was not a KRL to begin with then continue below */
519 if (r != SSH_ERR_KRL_BAD_MAGIC)
523 * If the file is not a KRL or we can't handle KRLs then attempt to
524 * parse the file as a flat list of keys.
526 switch ((r = sshkey_in_file(key, revoked_keys_file, 0, 1))) {
528 /* Key found => revoked */
529 return SSH_ERR_KEY_REVOKED;
530 case SSH_ERR_KEY_NOT_FOUND:
531 /* Key not found => not revoked */
534 /* Some other error occurred */