xref: /illumos-gate/usr/src/uts/common/gssapi/mechs/krb5/crypto/prng.c (revision 9fb67ea305c66b6a297583b9b0db6796b0dfe497)
1 /*
2  * Copyright 2005 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 
30 #include <k5-int.h>
31 
32 #ifdef _KERNEL
33 #include <sys/random.h>
34 #endif
35 
36 #ifndef _KERNEL
37 
38 /*
39  * Solaris kerberos:  we don't need a random number generator
40  * for the /dev/[u]random, as it uses entropy in the kernel.
41  * Keep this function as some apps might call it directly.
42  */
43 
44 /*ARGSUSED*/
45 krb5_error_code KRB5_CALLCONV
46 krb5_c_random_seed(krb5_context context, krb5_data *data)
47 {
48 	/*
49 	 * We can't do much if this fails, so ignore the
50 	 * return code.  /dev/urandom has its own entropy
51 	 * source, so seeding it from here is of questionable
52 	 * value in the first place.
53 	 */
54 	(void) C_SeedRandom(krb_ctx_hSession(context),
55 		(CK_BYTE_PTR)data->data,
56 		(CK_ULONG)data->length);
57 
58 	return(0);
59 }
60 #endif /* !_KERNEL */
61 
62 /*
63  * krb5_get_random_octets
64  *   New for Solaris 9.  This routine takes advantage of the new
65  * /dev/[u]random interface provided in Solaris 9 for getting random
66  * bytes generated from the kernel.  The entropy produced there is generally
67  * considered better than the current MIT PRNG code that we are replacing.
68  *
69  * This func is visible so that it can be used to generate a
70  * random confounder.
71  */
72 
73 #ifndef _KERNEL
74 
75 #endif /* ! _KERNEL */
76 
77 /*
78  * We can assume that the memory for data is already malloc'd.
79  * Return an error if there is an error, but don't clear the data->length
80  * or free data->data.  This will be done by the calling function.
81  */
82 
83 /*ARGSUSED*/
84 krb5_error_code KRB5_CALLCONV
85 krb5_c_random_make_octets(krb5_context context, krb5_data *data)
86 {
87 /*
88  * Solaris kerberos uses /dev/[u]random
89  */
90 #ifndef _KERNEL /* User space code */
91 
92     krb5_error_code err = 0;
93     CK_RV rv;
94 
95     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() start, user space using "
96 	"krb5_get_random_octets()\n");
97 
98     rv = C_GenerateRandom(krb_ctx_hSession(context), (CK_BYTE_PTR)data->data,
99 		(CK_ULONG)data->length);
100 
101     if (rv != CKR_OK) {
102 	KRB5_LOG(KRB5_ERR, "C_GenerateRandom failed in "
103 		"krb5_c_random_make_octets: rv = 0x%x.", rv);
104 	err = PKCS_ERR;
105     }
106     if (err != 0) {
107 	KRB5_LOG0(KRB5_ERR, "krb5_c_random_make_octets() end, error");
108 	return (err);
109     }
110 
111 #else  /* Kernel code section */
112 
113     /*
114      * Solaris Kerberos: for kernel code we use the randomness generator native
115      * to Solaris 9.  We avoid global variables and other nastiness this way.
116      *
117      * Using random_get_pseudo_bytes() instead of random_get_bytes() because it
118      * will not return an error code if there isn't enough entropy but will use
119      * a pseudo random algorithm to produce randomness.  Most of the time it
120      * should be as good as random_get_bytes() and we don't have to worry about
121      * dealing with a non-fatal error.
122      */
123     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() start, kernel using "
124 	    "random_get_pseudo_bytes()\n ");
125 
126     if(random_get_pseudo_bytes((uint8_t *)data->data, data->length) != 0) {
127 	KRB5_LOG0(KRB5_ERR, "krb5_c_random_make_octets() end, "
128 		"random_get_pseudo_bytes() error.\n");
129 	return(KRB5_CRYPTO_INTERNAL);
130     }
131 
132 #endif /* !_KERNEL */
133 
134     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() end\n");
135     return(0);
136 }
137