1 /* $NetBSD: rand-w32.c,v 1.2 2017/01/28 21:31:47 christos Exp $ */
2
3 /*
4 * Copyright (c) 2006 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37 #include <krb5/roken.h>
38
39 #include <wincrypt.h>
40
41 #include <rand.h>
42 #include <heim_threads.h>
43
44 #include "randi.h"
45
46 volatile static HCRYPTPROV g_cryptprovider = NULL;
47
48 static HCRYPTPROV
_hc_CryptProvider(void)49 _hc_CryptProvider(void)
50 {
51 BOOL rv;
52 HCRYPTPROV cryptprovider = NULL;
53
54 if (g_cryptprovider != NULL)
55 goto out;
56
57 rv = CryptAcquireContext(&cryptprovider, NULL,
58 MS_ENHANCED_PROV, PROV_RSA_FULL,
59 CRYPT_VERIFYCONTEXT);
60
61 if (GetLastError() == NTE_BAD_KEYSET) {
62 rv = CryptAcquireContext(&cryptprovider, NULL,
63 MS_ENHANCED_PROV, PROV_RSA_FULL,
64 CRYPT_NEWKEYSET);
65 }
66
67 if (rv) {
68 /* try the default provider */
69 rv = CryptAcquireContext(&cryptprovider, NULL, 0, PROV_RSA_FULL,
70 CRYPT_VERIFYCONTEXT);
71
72 if (GetLastError() == NTE_BAD_KEYSET) {
73 rv = CryptAcquireContext(&cryptprovider, NULL,
74 MS_ENHANCED_PROV, PROV_RSA_FULL,
75 CRYPT_NEWKEYSET);
76 }
77 }
78
79 if (rv) {
80 /* try just a default random number generator */
81 rv = CryptAcquireContext(&cryptprovider, NULL, 0, PROV_RNG,
82 CRYPT_VERIFYCONTEXT);
83 }
84
85 if (rv == 0 &&
86 InterlockedCompareExchangePointer((PVOID *) &g_cryptprovider,
87 (PVOID) cryptprovider, NULL) != 0) {
88
89 CryptReleaseContext(cryptprovider, 0);
90 }
91
92 out:
93 return g_cryptprovider;
94 }
95
96 /*
97 *
98 */
99
100
101 static void
w32crypto_seed(const void * indata,int size)102 w32crypto_seed(const void *indata, int size)
103 {
104 }
105
106
107 static int
w32crypto_bytes(unsigned char * outdata,int size)108 w32crypto_bytes(unsigned char *outdata, int size)
109 {
110 if (CryptGenRandom(_hc_CryptProvider(), size, outdata))
111 return 1;
112 return 0;
113 }
114
115 static void
w32crypto_cleanup(void)116 w32crypto_cleanup(void)
117 {
118 HCRYPTPROV cryptprovider;
119
120 if (InterlockedCompareExchangePointer((PVOID *) &cryptprovider,
121 0, (PVOID) g_cryptprovider) == 0) {
122 CryptReleaseContext(cryptprovider, 0);
123 }
124 }
125
126 static void
w32crypto_add(const void * indata,int size,double entropi)127 w32crypto_add(const void *indata, int size, double entropi)
128 {
129 }
130
131 static int
w32crypto_status(void)132 w32crypto_status(void)
133 {
134 if (_hc_CryptProvider() == 0)
135 return 0;
136 return 1;
137 }
138
139 const RAND_METHOD hc_rand_w32crypto_method = {
140 w32crypto_seed,
141 w32crypto_bytes,
142 w32crypto_cleanup,
143 w32crypto_add,
144 w32crypto_bytes,
145 w32crypto_status
146 };
147
148 const RAND_METHOD *
RAND_w32crypto_method(void)149 RAND_w32crypto_method(void)
150 {
151 return &hc_rand_w32crypto_method;
152 }
153