1 /* 2 * Copyright (c) 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 #include <windows.h> 27 28 #include <jni.h> 29 #include "jni_util.h" 30 #include "sun_misc_SystemRandomImpl.h" 31 32 static BOOLEAN (APIENTRY *rtlGenRandomFn)(void*, ULONG) = 0; 33 34 /* 35 * Load library (increment reference count), obtain the rtlGenRandomFn 36 * function pointer and return a library handle 37 */ 38 JNIEXPORT jlong JNICALL Java_sun_misc_SystemRandomImpl_init0 39 (JNIEnv *env, jclass clazz) 40 { 41 HMODULE hLib = LoadLibraryA("ADVAPI32.DLL"); 42 if (!hLib) { 43 JNU_ThrowByName(env, "java/lang/UnsupportedOperationException", "Can't load ADVAPI32.DLL"); 44 return 0; 45 } 46 47 if (!rtlGenRandomFn) { 48 rtlGenRandomFn = (BOOLEAN (APIENTRY *)(void*,ULONG))GetProcAddress(hLib, "SystemFunction036"); 49 } 50 51 if (!rtlGenRandomFn) { 52 FreeLibrary(hLib); 53 JNU_ThrowByName(env, "java/lang/UnsupportedOperationException", "Can't obtain ADVAPI32!RtlGenRandom function."); 54 return 0; 55 } 56 57 return (jlong)hLib; 58 } 59 60 /* 61 * Obtain random bytes 62 */ 63 JNIEXPORT void JNICALL Java_sun_misc_SystemRandomImpl_getBytes0 64 (JNIEnv *env, jclass clazz, jbyteArray randArray) 65 { 66 jsize numBytes = (*env)->GetArrayLength(env, randArray); 67 jbyte* randBytes = (*env)->GetByteArrayElements(env, randArray, NULL); 68 if (randBytes == NULL) { 69 JNU_ThrowByName(env, "java/lang/RuntimeException", "Can't obtain byte[] elements."); 70 return; 71 } 72 73 if (!rtlGenRandomFn(randBytes, numBytes)) { 74 (*env)->ReleaseByteArrayElements(env, randArray, randBytes, 0); 75 JNU_ThrowByName(env, "java/lang/RuntimeException", "RtlGenRandom function failed."); 76 return; 77 } 78 79 (*env)->ReleaseByteArrayElements(env, randArray, randBytes, 0); 80 } 81 82 /* 83 * Unload the library (decrement reference count) 84 */ 85 JNIEXPORT void JNICALL Java_sun_misc_SystemRandomImpl_deinit0 86 (JNIEnv *env, jclass clazz, jlong libraryHandle) 87 { 88 FreeLibrary((HMODULE) libraryHandle); 89 }