xref: /openbsd-src/lib/libc/crypt/cryptutil.c (revision af808b3f20e1ab1f31409a978e9420cbbddfad1e)
1 /* $OpenBSD: cryptutil.c,v 1.6 2014/12/24 22:10:34 tedu Exp $ */
2 /*
3  * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 #include <stdlib.h>
18 #include <unistd.h>
19 #include <string.h>
20 #include <pwd.h>
21 #include <login_cap.h>
22 #include <errno.h>
23 
24 int
25 crypt_checkpass(const char *pass, const char *goodhash)
26 {
27 	char dummy[_PASSWORD_LEN];
28 	char *res;
29 
30 	if (goodhash == NULL) {
31 		/* fake it */
32 		goto fake;
33 	}
34 
35 	/* empty password */
36 	if (strlen(goodhash) == 0 && strlen(pass) == 0)
37 		return 0;
38 
39 	if (goodhash[0] == '$' && goodhash[1] == '2') {
40 		if (bcrypt_checkpass(pass, goodhash))
41 			goto fail;
42 		return 0;
43 	}
44 
45 	/* unsupported. fake it. */
46 fake:
47 	bcrypt_newhash(pass, 8, dummy, sizeof(dummy));
48 fail:
49 	errno = EACCES;
50 	return -1;
51 }
52 
53 int
54 crypt_newhash(const char *pass, const char *pref, char *hash, size_t hashlen)
55 {
56 	int rv = -1;
57 	const char *defaultpref = "blowfish,8";
58 	const char *errstr;
59 	int rounds;
60 
61 	if (pref == NULL)
62 		pref = defaultpref;
63 	if (strncmp(pref, "blowfish,", 9) != 0) {
64 		errno = EINVAL;
65 		goto err;
66 	}
67 	rounds = strtonum(pref + 9, 4, 31, &errstr);
68 	if (errstr)
69 		goto err;
70 	rv = bcrypt_newhash(pass, rounds, hash, hashlen);
71 
72 err:
73 	return rv;
74 }
75