getentropy from Theo de Raadt

git-svn-id: file:///svn/unbound/trunk@3189 be551aaa-1e26-0410-a405-d3ace91eadb9

diff --git a/compat/getentropy_win.c b/compat/getentropy_win.c
index cad15d4aabd0c76323147482bf85c4671ded4e0d..00cce559a073397172b1e09a5a7d68c06128438a 100644 (file)
--- a/compat/getentropy_win.c
+++ b/compat/getentropy_win.c
@@ -1,65 +1,55 @@
-/* getentropy_win.c - get entropy on Windows.
-*
- * Copyright (c) 2014, NLnet Labs. All rights reserved.
+/*     $OpenBSD$       */
+
+/*
+ * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org> 
+ * Copyright (c) 2014, Bob Beck <beck@obtuse.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
  *
- * This software is open source.
- * 
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 
- * Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- * 
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- * 
- * Neither the name of the NLNET LABS nor the names of its contributors may
- * be used to endorse or promote products derived from this software without
- * specific prior written permission.
- * 
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
- * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 #include "config.h"
 
+#include <stdint.h>
+#include <sys/types.h>
+#include <wincrypt.h>
+#include <process.h>
+
+int    getentropy(void *buf, size_t len);
+
+/*
+ * On Windows, CryptGenRandom is supposed to be a well-seeded
+ * cryptographically strong random number generator.
+ */
 int
 getentropy(void *buf, size_t len)
 {
-       HMODULE lib;
+       HCRYPTPROV provider;
 
-       if(len > 256) {
+       if (len > 256) {
                errno = EIO;
                return -1;
        }
 
-       /* Get entropy with windows secure random number generator,
-        * for windows XP and later, it is in the ADVAPI32 dll */
-       lib = LoadLibrary("ADVAPI32.DLL");
-       if(lib) {
-               /* Load the RtlGenRandom function */
-               BOOLEAN (APIENTRY* genrandom)(void*,ULONG) =
-                       (BOOLEAN (APIENTRY*)(void*,ULONG))
-                       GetProcAddress(lib, "SystemFunction036");
-               if(genrandom) {
-                       if(genrandom(buf, len)) {
-                               FreeLibrary(lib);
-                               return 0; /* success */
-                       }
-               }
-               FreeLibrary(lib);
+       if (CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL,
+           CRYPT_VERIFYCONTEXT) != 0)
+               goto fail;
+       if (CryptGenRandom(provider, len, buf) != 0) {
+               CryptReleaseContext(provider, 0);
+               goto fail;
        }
+       CryptReleaseContext(provider, 0);
+       return (0);
 
+fail:
        errno = EIO;
-       return -1;
+       return (-1);
 }