jdk

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/*
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 * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.  Oracle designates this
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 * particular file as subject to the "Classpath" exception as provided
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 * by Oracle in the LICENSE file that accompanied this code.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 */
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#include <windows.h>
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#include <wincrypt.h>
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#include <jni.h>
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#include "sun_security_provider_NativeSeedGenerator.h"
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/*
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 * Get a random seed from the MS CryptoAPI. Return true if successful, false
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 * otherwise.
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 *
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 * Some early versions of Windows 95 do not support the required functions.
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 * Use runtime linking to avoid problems.
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 *
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 */
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JNIEXPORT jboolean JNICALL Java_sun_security_provider_NativeSeedGenerator_nativeGenerateSeed
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  (JNIEnv *env, jclass clazz, jbyteArray randArray)
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{
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    HCRYPTPROV hCryptProv;
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    jboolean result = JNI_FALSE;
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    jsize numBytes;
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    jbyte* randBytes;
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    if (CryptAcquireContextA(&hCryptProv, "J2SE", NULL, PROV_RSA_FULL, 0) == FALSE) {
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        /* If CSP context hasn't been created, create one. */
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        if (CryptAcquireContextA(&hCryptProv, "J2SE", NULL, PROV_RSA_FULL,
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                CRYPT_NEWKEYSET) == FALSE) {
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            return result;
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        }
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    }
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    numBytes = (*env)->GetArrayLength(env, randArray);
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    randBytes = (*env)->GetByteArrayElements(env, randArray, NULL);
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    if (randBytes == NULL) {
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        goto cleanup;
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    }
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    if (CryptGenRandom(hCryptProv, numBytes, randBytes)) {
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        result = JNI_TRUE;
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    }
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    (*env)->ReleaseByteArrayElements(env, randArray, randBytes, 0);
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cleanup:
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    CryptReleaseContext(hCryptProv, 0);
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    return result;
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}
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