xref: /titanic_41/usr/src/lib/pkcs11/libpkcs11/common/metaRand.c (revision 4b22b9337f359bfd063322244f5336cc7c6ffcfa)
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 2006 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 /*
29  * Random Number Generation Functions
30  * (as defined in PKCS#11 spec section 11.15)
31  *
32  */
33 
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <fcntl.h>
37 #include <errno.h>
38 #include <string.h>
39 
40 #include "metaGlobal.h"
41 
42 /*
43  * meta_SeedRandom
44  *
45  * Unlike most other metaslot functions, meta_SeedRandom does not distribute
46  * the call to a specific provider. Rather, we assume that the /dev/urandom
47  * implementation is a kCF consumer, and is pulling randomness from everywhere
48  * it can. Thus, by seeding /dev/urandom we let kCF potentially do all the
49  * work.
50  *
51  * NOTES:
52  * 1) /dev/urandom vs. /dev/random... Unfortunately P11 does not allow app
53  *    to request a "quality", so we'll just assume urandom is good enough.
54  *    Concerned apps can pull hardcore randomness from specific places they
55  *    trust (eg by checking for CKF_HW?)..
56  *
57  */
58 CK_RV
59 meta_SeedRandom(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pSeed,
60     CK_ULONG ulSeedLen)
61 {
62 	CK_RV rv;
63 	meta_session_t *session;
64 	ssize_t n;
65 
66 	if (pSeed == NULL || ulSeedLen == 0)
67 		return (CKR_ARGUMENTS_BAD);
68 
69 	/* Just check handle for validity, we don't need it for anything. */
70 	rv = meta_handle2session(hSession, &session);
71 	if (rv != CKR_OK)
72 		return (rv);
73 	REFRELEASE(session);
74 
75 	if (meta_urandom_seed_fd < 0) {
76 		(void) pthread_mutex_lock(&initmutex);
77 			/* Check again holding the mutex */
78 			if (meta_urandom_seed_fd < 0) {
79 				while ((meta_urandom_seed_fd = open(
80 				    RANDOM_DEVICE, O_WRONLY)) < 0) {
81 					if (errno != EINTR)
82 						break;
83 				}
84 				if (meta_urandom_seed_fd < 0) {
85 					(void) pthread_mutex_unlock(&initmutex);
86 					if (errno == EACCES)
87 						return (
88 						CKR_RANDOM_SEED_NOT_SUPPORTED);
89 					return (CKR_DEVICE_ERROR);
90 				}
91 				(void) fcntl(meta_urandom_seed_fd, F_SETFD,
92 				    FD_CLOEXEC);
93 			}
94 		(void) pthread_mutex_unlock(&initmutex);
95 	}
96 
97 	n = looping_write(meta_urandom_seed_fd, pSeed, ulSeedLen);
98 	if (n <= 0) {
99 		return (CKR_DEVICE_ERROR);
100 	}
101 
102 	return (CKR_OK);
103 }
104 
105 /*
106  * meta_GenerateRandom
107  *
108  * Unlike most other metaslot functions, meta_GenerateRandom does not distribute
109  * the call to a specific provider. Rather, we assume that the /dev/urandom
110  * implementation is a kCF consumer, and is pulling randomness from everywhere
111  * it can. Thus, by reading /dev/urandom we let kCF potentially do all the
112  * work.
113  *
114  */
115 CK_RV
116 meta_GenerateRandom(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pRandomData,
117     CK_ULONG ulRandomLen)
118 {
119 	CK_RV rv;
120 	meta_session_t *session;
121 	int fd;
122 	ssize_t n;
123 
124 	if (pRandomData == NULL || ulRandomLen < 1)
125 		return (CKR_ARGUMENTS_BAD);
126 
127 	/* Just check handle for validity, we don't need it for anything. */
128 	rv = meta_handle2session(hSession, &session);
129 	if (rv != CKR_OK)
130 		return (rv);
131 	REFRELEASE(session);
132 
133 	while ((fd = open(RANDOM_DEVICE, O_RDONLY)) < 0) {
134 		if (errno != EINTR)
135 			break;
136 	}
137 	if (fd == -1) {
138 		return (CKR_DEVICE_ERROR);
139 	}
140 
141 	n = looping_read(fd, pRandomData, ulRandomLen);
142 	if (n <= 0) {
143 		(void) close(fd);
144 		return (CKR_DEVICE_ERROR);
145 	}
146 
147 	(void) close(fd);
148 
149 	return (CKR_OK);
150 }
151