xref: /illumos-gate/usr/src/lib/pkcs11/libpkcs11/common/metaRand.c (revision c211fc479225fa54805cf480633bf6689ca9a2db)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Random Number Generation Functions
28  * (as defined in PKCS#11 spec section 11.15)
29  *
30  */
31 
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 #include <fcntl.h>
35 #include <errno.h>
36 #include <string.h>
37 
38 #include "metaGlobal.h"
39 
40 /*
41  * meta_SeedRandom
42  *
43  * Unlike most other metaslot functions, meta_SeedRandom does not distribute
44  * the call to a specific provider. Rather, we assume that the /dev/urandom
45  * implementation is a kCF consumer, and is pulling randomness from everywhere
46  * it can. Thus, by seeding /dev/urandom we let kCF potentially do all the
47  * work.
48  *
49  * NOTES:
50  * 1) /dev/urandom vs. /dev/random... Unfortunately P11 does not allow app
51  *    to request a "quality", so we'll just assume urandom is good enough.
52  *    Concerned apps can pull hardcore randomness from specific places they
53  *    trust (eg by checking for CKF_HW?)..
54  *
55  */
56 CK_RV
57 meta_SeedRandom(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pSeed,
58     CK_ULONG ulSeedLen)
59 {
60 	CK_RV rv;
61 	meta_session_t *session;
62 	ssize_t n;
63 
64 	if (pSeed == NULL || ulSeedLen == 0)
65 		return (CKR_ARGUMENTS_BAD);
66 
67 	/* Just check handle for validity, we don't need it for anything. */
68 	rv = meta_handle2session(hSession, &session);
69 	if (rv != CKR_OK)
70 		return (rv);
71 	REFRELEASE(session);
72 
73 	if (meta_urandom_seed_fd < 0) {
74 		(void) pthread_mutex_lock(&initmutex);
75 		/* Check again holding the mutex */
76 		if (meta_urandom_seed_fd < 0) {
77 			meta_urandom_seed_fd = open_nointr(RANDOM_DEVICE,
78 			    O_WRONLY);
79 			if (meta_urandom_seed_fd < 0) {
80 				(void) pthread_mutex_unlock(&initmutex);
81 				if (errno == EACCES)
82 					return (CKR_RANDOM_SEED_NOT_SUPPORTED);
83 				return (CKR_DEVICE_ERROR);
84 			}
85 		}
86 		(void) pthread_mutex_unlock(&initmutex);
87 	}
88 
89 	n = writen_nointr(meta_urandom_seed_fd, pSeed, ulSeedLen);
90 	if (n <= 0) {
91 		return (CKR_DEVICE_ERROR);
92 	}
93 
94 	return (CKR_OK);
95 }
96 
97 /*
98  * meta_GenerateRandom
99  *
100  * Unlike most other metaslot functions, meta_GenerateRandom does not distribute
101  * the call to a specific provider. Rather, we assume that the /dev/urandom
102  * implementation is a kCF consumer, and is pulling randomness from everywhere
103  * it can. Thus, by reading /dev/urandom we let kCF potentially do all the
104  * work.
105  *
106  */
107 CK_RV
108 meta_GenerateRandom(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pRandomData,
109     CK_ULONG ulRandomLen)
110 {
111 	CK_RV rv;
112 	meta_session_t *session;
113 	int fd;
114 	ssize_t n;
115 
116 	if (pRandomData == NULL || ulRandomLen < 1)
117 		return (CKR_ARGUMENTS_BAD);
118 
119 	/* Just check handle for validity, we don't need it for anything. */
120 	rv = meta_handle2session(hSession, &session);
121 	if (rv != CKR_OK)
122 		return (rv);
123 	REFRELEASE(session);
124 
125 	fd = open_nointr(RANDOM_DEVICE, O_RDONLY);
126 	if (fd == -1) {
127 		return (CKR_DEVICE_ERROR);
128 	}
129 
130 	n = readn_nointr(fd, pRandomData, ulRandomLen);
131 	if (n <= 0) {
132 		(void) close(fd);
133 		return (CKR_DEVICE_ERROR);
134 	}
135 
136 	(void) close(fd);
137 
138 	return (CKR_OK);
139 }
140