1/*
2 * Copyright (c) 2002, 2014, 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 */
44JNIEXPORT 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 (randBytes == NULL) {
63        goto cleanup;
64    }
65
66    if (CryptGenRandom(hCryptProv, numBytes, randBytes)) {
67        result = JNI_TRUE;
68    }
69    (*env)->ReleaseByteArrayElements(env, randArray, randBytes, 0);
70
71cleanup:
72    CryptReleaseContext(hCryptProv, 0);
73
74    return result;
75}
76