1 /*
   2  * Copyright (c) 2002, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /* Need to define this to get CAPI functions included */
  27 #ifndef _WIN32_WINNT
  28 #define _WIN32_WINNT 0x0400
  29 #endif
  30 
  31 #include <windows.h>
  32 #include <wincrypt.h>
  33 #include <jni.h>
  34 #include "sun_security_provider_NativeSeedGenerator.h"
  35 
  36 /*
  37  * Get a random seed from the MS CryptoAPI. Return true if successful, false
  38  * otherwise.
  39  *
  40  * Some early versions of Windows 95 do not support the required functions.
  41  * Use runtime linking to avoid problems.
  42  *
  43  */
  44 JNIEXPORT jboolean JNICALL Java_sun_security_provider_NativeSeedGenerator_nativeGenerateSeed
  45   (JNIEnv *env, jclass clazz, jbyteArray randArray)
  46 {
  47     HCRYPTPROV hCryptProv;
  48     jboolean result = JNI_FALSE;
  49     jsize numBytes;
  50     jbyte* randBytes;
  51 
  52     if (CryptAcquireContextA(&hCryptProv, "J2SE", NULL, PROV_RSA_FULL, 0) == FALSE) {
  53         /* If CSP context hasn't been created, create one. */
  54         if (CryptAcquireContextA(&hCryptProv, "J2SE", NULL, PROV_RSA_FULL,
  55                 CRYPT_NEWKEYSET) == FALSE) {
  56             return result;
  57         }
  58     }
  59 
  60     numBytes = (*env)->GetArrayLength(env, randArray);
  61     randBytes = (*env)->GetByteArrayElements(env, randArray, NULL);




  62     if (CryptGenRandom(hCryptProv, numBytes, randBytes)) {
  63         result = JNI_TRUE;
  64     }
  65     (*env)->ReleaseByteArrayElements(env, randArray, randBytes, 0);
  66 

  67     CryptReleaseContext(hCryptProv, 0);
  68 
  69     return result;
  70 }
--- EOF ---