xref: /illumos-gate/usr/src/lib/libcryptoutil/common/random.c (revision bea83d026ee1bd1b2a2419e1d0232f107a5d7d9b)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <stdio.h>
29 #include <string.h>
30 #include <fcntl.h>
31 #include <locale.h>
32 #include <cryptoutil.h>
33 
34 #define	RANDOM_DEVICE		"/dev/urandom"	/* random device name */
35 
36 /*
37  * Put the requested amount of random data into a preallocated buffer.
38  * Good for passphrase salts, initialization vectors.
39  */
40 int
41 pkcs11_random_data(void *dbuf, size_t dlen)
42 {
43 	int	fd;
44 
45 	if (dbuf == NULL || dlen == 0)
46 		return (0);
47 
48 	/* Read random data directly from /dev/urandom */
49 	if ((fd = open(RANDOM_DEVICE, O_RDONLY)) != -1) {
50 		if (read(fd, dbuf, dlen) == dlen) {
51 			(void) close(fd);
52 			return (0);
53 		}
54 		(void) close(fd);
55 	}
56 	return (-1);
57 }
58