xref: /illumos-gate/usr/src/uts/common/gssapi/mechs/krb5/crypto/prng.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 #pragma ident	"%Z%%M%	%I%	%E% SMI"
7 
8 /*
9  * Copyright (C) 1998 by the FundsXpress, INC.
10  *
11  * All rights reserved.
12  *
13  * Export of this software from the United States of America may require
14  * a specific license from the United States Government.  It is the
15  * responsibility of any person or organization contemplating export to
16  * obtain such a license before exporting.
17  *
18  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
19  * distribute this software and its documentation for any purpose and
20  * without fee is hereby granted, provided that the above copyright
21  * notice appear in all copies and that both that copyright notice and
22  * this permission notice appear in supporting documentation, and that
23  * the name of FundsXpress. not be used in advertising or publicity pertaining
24  * to distribution of the software without specific, written prior
25  * permission.  FundsXpress makes no representations about the suitability of
26  * this software for any purpose.  It is provided "as is" without express
27  * or implied warranty.
28  *
29  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
30  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
31  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
32  */
33 
34 #include <k5-int.h>
35 
36 #ifdef _KERNEL
37 #include <sys/random.h>
38 #endif
39 
40 #ifndef _KERNEL
41 
42 /*
43  * Solaris kerberos:  we don't need a random number generator
44  * for the /dev/[u]random, as it uses entropy in the kernel.
45  * Keep this function as some apps might call it directly.
46  */
47 
48 /*ARGSUSED*/
49 KRB5_DLLIMP krb5_error_code KRB5_CALLCONV
50 krb5_c_random_seed(krb5_context context, krb5_data *data)
51 {
52 	/*
53 	 * We can't do much if this fails, so ignore the
54 	 * return code.  /dev/urandom has its own entropy
55 	 * source, so seeding it from here is of questionable
56 	 * value in the first place.
57 	 */
58 	(void) C_SeedRandom(krb_ctx_hSession(context),
59 		(CK_BYTE_PTR)data->data,
60 		(CK_ULONG)data->length);
61 
62 	return(0);
63 }
64 #endif /* !_KERNEL */
65 
66 /*
67  * krb5_get_random_octets
68  *   New for Solaris 9.  This routine takes advantage of the new
69  * /dev/[u]random interface provided in Solaris 9 for getting random
70  * bytes generated from the kernel.  The entropy produced there is generally
71  * considered better than the current MIT PRNG code that we are replacing.
72  *
73  * This func is visible so that it can be used to generate a
74  * random confounder.
75  */
76 
77 #ifndef _KERNEL
78 
79 #endif /* ! _KERNEL */
80 
81 /*
82  * We can assume that the memory for data is already malloc'd.
83  * Return an error if there is an error, but don't clear the data->length
84  * or free data->data.  This will be done by the calling function.
85  */
86 
87 /*ARGSUSED*/
88 KRB5_DLLIMP krb5_error_code KRB5_CALLCONV
89 krb5_c_random_make_octets(krb5_context context, krb5_data *data)
90 {
91 /*
92  * Solaris kerberos uses /dev/[u]random
93  */
94 #ifndef _KERNEL /* User space code */
95 
96     krb5_error_code err = 0;
97     CK_RV rv;
98 
99     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() start, user space using "
100 	"krb5_get_random_octets()\n");
101 
102     rv = C_GenerateRandom(krb_ctx_hSession(context), (CK_BYTE_PTR)data->data,
103 		(CK_ULONG)data->length);
104 
105     if (rv != CKR_OK) {
106 	KRB5_LOG(KRB5_ERR, "C_GenerateRandom failed in "
107 		"krb5_c_random_make_octets: rv = 0x%x.", rv);
108 	err = PKCS_ERR;
109     }
110     if (err != 0) {
111 	KRB5_LOG0(KRB5_ERR, "krb5_c_random_make_octets() end, error");
112 	return (err);
113     }
114 
115 #else  /* Kernel code section */
116 
117     /*
118      * Solaris Kerberos: for kernel code we use the randomness generator native
119      * to Solaris 9.  We avoid global variables and other nastiness this way.
120      *
121      * Using random_get_pseudo_bytes() instead of random_get_bytes() because it
122      * will not return an error code if there isn't enough entropy but will use
123      * a pseudo random algorithm to produce randomness.  Most of the time it
124      * should be as good as random_get_bytes() and we don't have to worry about
125      * dealing with a non-fatal error.
126      */
127     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() start, kernel using "
128 	    "random_get_pseudo_bytes()\n ");
129 
130     if(random_get_pseudo_bytes((uint8_t *)data->data, data->length) != 0) {
131 	KRB5_LOG0(KRB5_ERR, "krb5_c_random_make_octets() end, "
132 		"random_get_pseudo_bytes() error.\n");
133 	return(KRB5_CRYPTO_INTERNAL);
134     }
135 
136 #endif /* !_KERNEL */
137 
138     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() end\n");
139     return(0);
140 }
141