/*

 * Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/* Need to define this to get CAPI functions included */

#ifndef _WIN32_WINNT

#define _WIN32_WINNT 0x0400

#endif

#include <windows.h>

#include <wincrypt.h>

#include <jni.h>

#include "sun_security_provider_NativeSeedGenerator.h"

/*

 * Get a random seed from the MS CryptoAPI. Return true if successful, false

 * otherwise.

 *

 * Some early versions of Windows 95 do not support the required functions.

 * Use runtime linking to avoid problems.

 *

 */

JNIEXPORT jboolean JNICALL Java_sun_security_provider_NativeSeedGenerator_nativeGenerateSeed

  (JNIEnv *env, jclass clazz, jbyteArray randArray)

{

    HCRYPTPROV hCryptProv;

    jboolean result = JNI_FALSE;

    jsize numBytes;

    jbyte* randBytes;

    if (CryptAcquireContextA(&hCryptProv, "J2SE", NULL, PROV_RSA_FULL, 0) == FALSE) {

        /* If CSP context hasn't been created, create one. */

        if (CryptAcquireContextA(&hCryptProv, "J2SE", NULL, PROV_RSA_FULL,

                CRYPT_NEWKEYSET) == FALSE) {

            return result;

        }

    }

    numBytes = (*env)->GetArrayLength(env, randArray);

    randBytes = (*env)->GetByteArrayElements(env, randArray, NULL);

    if (randBytes == NULL) {

        goto cleanup;

    }

    if (CryptGenRandom(hCryptProv, numBytes, randBytes)) {

        result = JNI_TRUE;

    }

    (*env)->ReleaseByteArrayElements(env, randArray, randBytes, 0);

cleanup:

    CryptReleaseContext(hCryptProv, 0);

    return result;

}