xref: /illumos-gate/usr/src/uts/common/gssapi/mechs/krb5/crypto/prng.c (revision 9164a50bf932130cbb5097a16f6986873ce0e6e5)
1 /*
2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (C) 1998 by the FundsXpress, INC.
8  *
9  * All rights reserved.
10  *
11  * Export of this software from the United States of America may require
12  * a specific license from the United States Government.  It is the
13  * responsibility of any person or organization contemplating export to
14  * obtain such a license before exporting.
15  *
16  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
17  * distribute this software and its documentation for any purpose and
18  * without fee is hereby granted, provided that the above copyright
19  * notice appear in all copies and that both that copyright notice and
20  * this permission notice appear in supporting documentation, and that
21  * the name of FundsXpress. not be used in advertising or publicity pertaining
22  * to distribution of the software without specific, written prior
23  * permission.  FundsXpress makes no representations about the suitability of
24  * this software for any purpose.  It is provided "as is" without express
25  * or implied warranty.
26  */
27 
28 #include <k5-int.h>
29 
30 #ifdef _KERNEL
31 #include <sys/random.h>
32 #endif
33 
34 #ifndef _KERNEL
35 
36 /*
37  * Solaris kerberos:  we don't need a random number generator
38  * for the /dev/[u]random, as it uses entropy in the kernel.
39  * Keep this function as some apps might call it directly.
40  */
41 
42 /*ARGSUSED*/
43 krb5_error_code KRB5_CALLCONV
44 krb5_c_random_seed(krb5_context context, krb5_data *data)
45 {
46 	/*
47 	 * We can't do much if this fails, so ignore the
48 	 * return code.  /dev/urandom has its own entropy
49 	 * source, so seeding it from here is of questionable
50 	 * value in the first place.
51 	 */
52 	(void) C_SeedRandom(krb_ctx_hSession(context),
53 		(CK_BYTE_PTR)data->data,
54 		(CK_ULONG)data->length);
55 
56 	return(0);
57 }
58 #endif /* !_KERNEL */
59 
60 /*
61  * krb5_get_random_octets
62  *   New for Solaris 9.  This routine takes advantage of the new
63  * /dev/[u]random interface provided in Solaris 9 for getting random
64  * bytes generated from the kernel.  The entropy produced there is generally
65  * considered better than the current MIT PRNG code that we are replacing.
66  *
67  * This func is visible so that it can be used to generate a
68  * random confounder.
69  */
70 
71 #ifndef _KERNEL
72 
73 #endif /* ! _KERNEL */
74 
75 /*
76  * We can assume that the memory for data is already malloc'd.
77  * Return an error if there is an error, but don't clear the data->length
78  * or free data->data.  This will be done by the calling function.
79  */
80 
81 /*ARGSUSED*/
82 krb5_error_code KRB5_CALLCONV
83 krb5_c_random_make_octets(krb5_context context, krb5_data *data)
84 {
85 /*
86  * Solaris kerberos uses /dev/[u]random
87  */
88 #ifndef _KERNEL /* User space code */
89 
90     krb5_error_code err = 0;
91     CK_RV rv;
92 
93     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() start, user space using "
94 	"krb5_get_random_octets()\n");
95 
96     rv = C_GenerateRandom(krb_ctx_hSession(context), (CK_BYTE_PTR)data->data,
97 		(CK_ULONG)data->length);
98 
99     if (rv != CKR_OK) {
100 	KRB5_LOG(KRB5_ERR, "C_GenerateRandom failed in "
101 		"krb5_c_random_make_octets: rv = 0x%x.", rv);
102 	err = PKCS_ERR;
103     }
104     if (err != 0) {
105 	KRB5_LOG0(KRB5_ERR, "krb5_c_random_make_octets() end, error");
106 	return (err);
107     }
108 
109 #else  /* Kernel code section */
110 
111     /*
112      * Solaris Kerberos: for kernel code we use the randomness generator native
113      * to Solaris 9.  We avoid global variables and other nastiness this way.
114      *
115      * Using random_get_pseudo_bytes() instead of random_get_bytes() because it
116      * will not return an error code if there isn't enough entropy but will use
117      * a pseudo random algorithm to produce randomness.  Most of the time it
118      * should be as good as random_get_bytes() and we don't have to worry about
119      * dealing with a non-fatal error.
120      */
121     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() start, kernel using "
122 	    "random_get_pseudo_bytes()\n ");
123 
124     if(random_get_pseudo_bytes((uint8_t *)data->data, data->length) != 0) {
125 	KRB5_LOG0(KRB5_ERR, "krb5_c_random_make_octets() end, "
126 		"random_get_pseudo_bytes() error.\n");
127 	return(KRB5_CRYPTO_INTERNAL);
128     }
129 
130 #endif /* !_KERNEL */
131 
132     KRB5_LOG0(KRB5_INFO, "krb5_c_random_make_octets() end\n");
133     return(0);
134 }
135