1/*
2 * Copyright (c) 2006 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <config.h>
35#include <roken.h>
36
37#include <wincrypt.h>
38
39#include <stdio.h>
40#include <stdlib.h>
41#include <rand.h>
42#include <heim_threads.h>
43
44#include "randi.h"
45
46volatile static HCRYPTPROV g_cryptprovider = 0;
47
48static HCRYPTPROV
49_hc_CryptProvider(void)
50{
51    BOOL rv;
52    HCRYPTPROV cryptprovider = 0;
53
54    if (g_cryptprovider != 0)
55	return g_cryptprovider;
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 &&
86        InterlockedCompareExchangePointer((PVOID *) &g_cryptprovider,
87					  (PVOID) cryptprovider, 0) != 0) {
88
89        CryptReleaseContext(cryptprovider, 0);
90        cryptprovider = g_cryptprovider;
91    }
92
93    return cryptprovider;
94}
95
96/*
97 *
98 */
99
100
101static void
102w32crypto_seed(const void *indata, int size)
103{
104}
105
106
107static int
108w32crypto_bytes(unsigned char *outdata, int size)
109{
110    if (CryptGenRandom(_hc_CryptProvider(), size, outdata))
111	return 1;
112    return 0;
113}
114
115static void
116w32crypto_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
126static void
127w32crypto_add(const void *indata, int size, double entropi)
128{
129}
130
131static int
132w32crypto_status(void)
133{
134    if (_hc_CryptProvider() == 0)
135	return 0;
136    return 1;
137}
138
139const 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
148const RAND_METHOD *
149RAND_w32crypto_method(void)
150{
151    return &hc_rand_w32crypto_method;
152}
153