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 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 102 w32crypto_seed(const void *indata, int size) 103 { 104 } 105 106 107 static int 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 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 127 w32crypto_add(const void *indata, int size, double entropi) 128 { 129 } 130 131 static int 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 * 149 RAND_w32crypto_method(void) 150 { 151 return &hc_rand_w32crypto_method; 152 } 153