1 /* $OpenBSD: authfile.c,v 1.144 2023/03/14 07:26:25 dtucker 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)
62 r = sshbuf_write_file(filename, keybuf);
68 sshkey_save_private(struct sshkey *key, const char *filename,
69 const char *passphrase, const char *comment,
70 int format, const char *openssh_format_cipher, int openssh_format_rounds)
72 struct sshbuf *keyblob = NULL;
75 if ((keyblob = sshbuf_new()) == NULL)
76 return SSH_ERR_ALLOC_FAIL;
77 if ((r = sshkey_private_to_fileblob(key, keyblob, passphrase, comment,
78 format, openssh_format_cipher, openssh_format_rounds)) != 0)
80 if ((r = sshkey_save_private_blob(keyblob, filename)) != 0)
88 /* XXX remove error() calls from here? */
90 sshkey_perm_ok(int fd, const char *filename)
94 if (fstat(fd, &st) == -1)
95 return SSH_ERR_SYSTEM_ERROR;
97 * if a key owned by the user is accessed, then we check the
98 * permissions of the file. if the key owned by a different user,
102 if (check_ntsec(filename))
104 if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) {
105 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
106 error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @");
107 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
108 error("Permissions 0%3.3o for '%s' are too open.",
109 (u_int)st.st_mode & 0777, filename);
110 error("It is required that your private key files are NOT accessible by others.");
111 error("This private key will be ignored.");
112 return SSH_ERR_KEY_BAD_PERMISSIONS;
118 sshkey_load_private_type(int type, const char *filename, const char *passphrase,
119 struct sshkey **keyp, char **commentp)
125 if (commentp != NULL)
128 if ((fd = open(filename, O_RDONLY)) == -1)
129 return SSH_ERR_SYSTEM_ERROR;
131 r = sshkey_perm_ok(fd, filename);
135 r = sshkey_load_private_type_fd(fd, type, passphrase, keyp, commentp);
136 if (r == 0 && keyp && *keyp)
137 r = sshkey_set_filename(*keyp, filename);
144 sshkey_load_private(const char *filename, const char *passphrase,
145 struct sshkey **keyp, char **commentp)
147 return sshkey_load_private_type(KEY_UNSPEC, filename, passphrase,
152 sshkey_load_private_type_fd(int fd, int type, const char *passphrase,
153 struct sshkey **keyp, char **commentp)
155 struct sshbuf *buffer = NULL;
160 if ((r = sshbuf_load_fd(fd, &buffer)) != 0 ||
161 (r = sshkey_parse_private_fileblob_type(buffer, type,
162 passphrase, keyp, commentp)) != 0)
172 /* Load a pubkey from the unencrypted envelope of a new-format private key */
174 sshkey_load_pubkey_from_private(const char *filename, struct sshkey **pubkeyp)
176 struct sshbuf *buffer = NULL;
177 struct sshkey *pubkey = NULL;
183 if ((fd = open(filename, O_RDONLY)) == -1)
184 return SSH_ERR_SYSTEM_ERROR;
185 if ((r = sshbuf_load_fd(fd, &buffer)) != 0 ||
186 (r = sshkey_parse_pubkey_from_private_fileblob_type(buffer,
187 KEY_UNSPEC, &pubkey)) != 0)
189 if ((r = sshkey_set_filename(pubkey, filename)) != 0)
192 if (pubkeyp != NULL) {
205 sshkey_try_load_public(struct sshkey **kp, const char *filename,
209 char *line = NULL, *cp;
212 struct sshkey *k = NULL;
215 return SSH_ERR_INVALID_ARGUMENT;
217 if (commentp != NULL)
219 if ((f = fopen(filename, "r")) == NULL)
220 return SSH_ERR_SYSTEM_ERROR;
221 if ((k = sshkey_new(KEY_UNSPEC)) == NULL) {
223 return SSH_ERR_ALLOC_FAIL;
225 while (getline(&line, &linesize, f) != -1) {
233 /* Abort loading if this looks like a private key */
234 if (strncmp(cp, "-----BEGIN", 10) == 0 ||
235 strcmp(cp, "SSH PRIVATE KEY FILE") == 0)
237 /* Skip leading whitespace. */
238 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
241 if ((r = sshkey_read(k, &cp)) == 0) {
242 cp[strcspn(cp, "\r\n")] = '\0';
244 *commentp = strdup(*cp ?
246 if (*commentp == NULL)
247 r = SSH_ERR_ALLOC_FAIL;
260 return SSH_ERR_INVALID_FORMAT;
263 /* load public key from any pubkey file */
265 sshkey_load_public(const char *filename, struct sshkey **keyp, char **commentp)
267 char *pubfile = NULL;
272 if (commentp != NULL)
275 if ((r = sshkey_try_load_public(keyp, filename, commentp)) == 0)
278 /* try .pub suffix */
279 if (asprintf(&pubfile, "%s.pub", filename) == -1)
280 return SSH_ERR_ALLOC_FAIL;
281 if ((r = sshkey_try_load_public(keyp, pubfile, commentp)) == 0)
284 /* finally, try to extract public key from private key file */
285 if ((r = sshkey_load_pubkey_from_private(filename, keyp)) == 0)
288 /* Pretend we couldn't find the key */
289 r = SSH_ERR_SYSTEM_ERROR;
299 /* Load the certificate associated with the named private key */
301 sshkey_load_cert(const char *filename, struct sshkey **keyp)
303 struct sshkey *pub = NULL;
305 int r = SSH_ERR_INTERNAL_ERROR;
310 if (asprintf(&file, "%s-cert.pub", filename) == -1)
311 return SSH_ERR_ALLOC_FAIL;
313 r = sshkey_try_load_public(keyp, file, NULL);
319 /* Load private key and certificate */
321 sshkey_load_private_cert(int type, const char *filename, const char *passphrase,
322 struct sshkey **keyp)
324 struct sshkey *key = NULL, *cert = NULL;
335 #endif /* WITH_OPENSSL */
341 return SSH_ERR_KEY_TYPE_UNKNOWN;
344 if ((r = sshkey_load_private_type(type, filename,
345 passphrase, &key, NULL)) != 0 ||
346 (r = sshkey_load_cert(filename, &cert)) != 0)
349 /* Make sure the private key matches the certificate */
350 if (sshkey_equal_public(key, cert) == 0) {
351 r = SSH_ERR_KEY_CERT_MISMATCH;
355 if ((r = sshkey_to_certified(key)) != 0 ||
356 (r = sshkey_cert_copy(cert, key)) != 0)
370 * Returns success if the specified "key" is listed in the file "filename",
371 * SSH_ERR_KEY_NOT_FOUND: if the key is not listed or another error.
372 * If "strict_type" is set then the key type must match exactly,
373 * otherwise a comparison that ignores certificate data is performed.
374 * If "check_ca" is set and "key" is a certificate, then its CA key is
375 * also checked and sshkey_in_file() will return success if either is found.
378 sshkey_in_file(struct sshkey *key, const char *filename, int strict_type,
382 char *line = NULL, *cp;
385 struct sshkey *pub = NULL;
387 int (*sshkey_compare)(const struct sshkey *, const struct sshkey *) =
388 strict_type ? sshkey_equal : sshkey_equal_public;
390 if ((f = fopen(filename, "r")) == NULL)
391 return SSH_ERR_SYSTEM_ERROR;
393 while (getline(&line, &linesize, f) != -1) {
398 /* Skip leading whitespace. */
399 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++)
402 /* Skip comments and empty lines */
410 if ((pub = sshkey_new(KEY_UNSPEC)) == NULL) {
411 r = SSH_ERR_ALLOC_FAIL;
414 switch (r = sshkey_read(pub, &cp)) {
417 case SSH_ERR_KEY_LENGTH:
422 if (sshkey_compare(key, pub) ||
423 (check_ca && sshkey_is_cert(key) &&
424 sshkey_compare(key->cert->signature_key, pub))) {
429 r = SSH_ERR_KEY_NOT_FOUND;
438 * Checks whether the specified key is revoked, returning 0 if not,
439 * SSH_ERR_KEY_REVOKED if it is or another error code if something
440 * unexpected happened.
441 * This will check both the key and, if it is a certificate, its CA key too.
442 * "revoked_keys_file" may be a KRL or a one-per-line list of public keys.
445 sshkey_check_revoked(struct sshkey *key, const char *revoked_keys_file)
449 r = ssh_krl_file_contains_key(revoked_keys_file, key);
450 /* If this was not a KRL to begin with then continue below */
451 if (r != SSH_ERR_KRL_BAD_MAGIC)
455 * If the file is not a KRL or we can't handle KRLs then attempt to
456 * parse the file as a flat list of keys.
458 switch ((r = sshkey_in_file(key, revoked_keys_file, 0, 1))) {
460 /* Key found => revoked */
461 return SSH_ERR_KEY_REVOKED;
462 case SSH_ERR_KEY_NOT_FOUND:
463 /* Key not found => not revoked */
466 /* Some other error occurred */
472 * Advanced *cpp past the end of key options, defined as the first unquoted
473 * whitespace character. Returns 0 on success or -1 on failure (e.g.
474 * unterminated quotes).
477 sshkey_advance_past_options(char **cpp)
482 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
483 if (*cp == '\\' && cp[1] == '"')
484 cp++; /* Skip both */
489 /* return failure for unterminated quotes */
490 return (*cp == '\0' && quoted) ? -1 : 0;
493 /* Save a public key */
495 sshkey_save_public(const struct sshkey *key, const char *path,
500 int r = SSH_ERR_INTERNAL_ERROR;
502 if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
503 return SSH_ERR_SYSTEM_ERROR;
504 if ((f = fdopen(fd, "w")) == NULL) {
505 r = SSH_ERR_SYSTEM_ERROR;
509 if ((r = sshkey_write(key, f)) != 0)
511 fprintf(f, " %s\n", comment);
513 r = SSH_ERR_SYSTEM_ERROR;
516 if (fclose(f) != 0) {
517 r = SSH_ERR_SYSTEM_ERROR;