/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.crypto;
import java.nio.ByteBuffer;
import java.security.NoSuchAlgorithmException;
import java.util.StringTokenizer;
import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.ShortBufferException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.util.NativeCodeLoader;
import com.google.common.base.Preconditions;
/**
* OpenSSL cipher using JNI.
* Currently only AES-CTR is supported. It's flexible to add
* other crypto algorithms/modes.
*/
@InterfaceAudience.Private
public final class OpensslCipher {
private static final Log LOG =
LogFactory.getLog(OpensslCipher.class.getName());
public static final int ENCRYPT_MODE = 1;
public static final int DECRYPT_MODE = 0;
/** Currently only support AES/CTR/NoPadding. */
private static enum AlgMode {
AES_CTR;
static int get(String algorithm, String mode)
throws NoSuchAlgorithmException {
try {
return AlgMode.valueOf(algorithm + "_" + mode).ordinal();
} catch (Exception e) {
throw new NoSuchAlgorithmException("Doesn't support algorithm: " +
algorithm + " and mode: " + mode);
}
}
}
private static enum Padding {
NoPadding;
static int get(String padding) throws NoSuchPaddingException {
try {
return Padding.valueOf(padding).ordinal();
} catch (Exception e) {
throw new NoSuchPaddingException("Doesn't support padding: " + padding);
}
}
}
private long context = 0;
private final int alg;
private final int padding;
private static final String loadingFailureReason;
static {
String loadingFailure = null;
try {
if (!NativeCodeLoader.buildSupportsOpenssl()) {
loadingFailure = "build does not support openssl.";
} else {
initIDs();
}
} catch (Throwable t) {
loadingFailure = t.getMessage();
LOG.debug("Failed to load OpenSSL Cipher.", t);
} finally {
loadingFailureReason = loadingFailure;
}
}
public static String getLoadingFailureReason() {
return loadingFailureReason;
}
private OpensslCipher(long context, int alg, int padding) {
this.context = context;
this.alg = alg;
this.padding = padding;
}
/**
* Return an <code>OpensslCipher<code> object that implements the specified
* transformation.
*
* @param transformation the name of the transformation, e.g.,
* AES/CTR/NoPadding.
* @return OpensslCipher an <code>OpensslCipher<code> object
* @throws NoSuchAlgorithmException if <code>transformation</code> is null,
* empty, in an invalid format, or if Openssl doesn't implement the
* specified algorithm.
* @throws NoSuchPaddingException if <code>transformation</code> contains
* a padding scheme that is not available.
*/
public static final OpensslCipher getInstance(String transformation)
throws NoSuchAlgorithmException, NoSuchPaddingException {
Transform transform = tokenizeTransformation(transformation);
int algMode = AlgMode.get(transform.alg, transform.mode);
int padding = Padding.get(transform.padding);
long context = initContext(algMode, padding);
return new OpensslCipher(context, algMode, padding);
}
/** Nested class for algorithm, mode and padding. */
private static class Transform {
final String alg;
final String mode;
final String padding;
public Transform(String alg, String mode, String padding) {
this.alg = alg;
this.mode = mode;
this.padding = padding;
}
}
private static Transform tokenizeTransformation(String transformation)
throws NoSuchAlgorithmException {
if (transformation == null) {
throw new NoSuchAlgorithmException("No transformation given.");
}
/*
* Array containing the components of a Cipher transformation:
*
* index 0: algorithm (e.g., AES)
* index 1: mode (e.g., CTR)
* index 2: padding (e.g., NoPadding)
*/
String[] parts = new String[3];
int count = 0;
StringTokenizer parser = new StringTokenizer(transformation, "/");
while (parser.hasMoreTokens() && count < 3) {
parts[count++] = parser.nextToken().trim();
}
if (count != 3 || parser.hasMoreTokens()) {
throw new NoSuchAlgorithmException("Invalid transformation format: " +
transformation);
}
return new Transform(parts[0], parts[1], parts[2]);
}
/**
* Initialize this cipher with a key and IV.
*
* @param mode {@link #ENCRYPT_MODE} or {@link #DECRYPT_MODE}
* @param key crypto key
* @param iv crypto iv
*/
public void init(int mode, byte[] key, byte[] iv) {
context = init(context, mode, alg, padding, key, iv);
}
/**
* Continues a multiple-part encryption or decryption operation. The data
* is encrypted or decrypted, depending on how this cipher was initialized.
* <p/>
*
* All <code>input.remaining()</code> bytes starting at
* <code>input.position()</code> are processed. The result is stored in
* the output buffer.
* <p/>
*
* Upon return, the input buffer's position will be equal to its limit;
* its limit will not have changed. The output buffer's position will have
* advanced by n, when n is the value returned by this method; the output
* buffer's limit will not have changed.
* <p/>
*
* If <code>output.remaining()</code> bytes are insufficient to hold the
* result, a <code>ShortBufferException</code> is thrown.
*
* @param input the input ByteBuffer
* @param output the output ByteBuffer
* @return int number of bytes stored in <code>output</code>
* @throws ShortBufferException if there is insufficient space in the
* output buffer
*/
public int update(ByteBuffer input, ByteBuffer output)
throws ShortBufferException {
checkState();
Preconditions.checkArgument(input.isDirect() && output.isDirect(),
"Direct buffers are required.");
int len = update(context, input, input.position(), input.remaining(),
output, output.position(), output.remaining());
input.position(input.limit());
output.position(output.position() + len);
return len;
}
/**
* Finishes a multiple-part operation. The data is encrypted or decrypted,
* depending on how this cipher was initialized.
* <p/>
*
* The result is stored in the output buffer. Upon return, the output buffer's
* position will have advanced by n, where n is the value returned by this
* method; the output buffer's limit will not have changed.
* <p/>
*
* If <code>output.remaining()</code> bytes are insufficient to hold the result,
* a <code>ShortBufferException</code> is thrown.
* <p/>
*
* Upon finishing, this method resets this cipher object to the state it was
* in when previously initialized. That is, the object is available to encrypt
* or decrypt more data.
* <p/>
*
* If any exception is thrown, this cipher object need to be reset before it
* can be used again.
*
* @param output the output ByteBuffer
* @return int number of bytes stored in <code>output</code>
* @throws ShortBufferException
* @throws IllegalBlockSizeException
* @throws BadPaddingException
*/
public int doFinal(ByteBuffer output) throws ShortBufferException,
IllegalBlockSizeException, BadPaddingException {
checkState();
Preconditions.checkArgument(output.isDirect(), "Direct buffer is required.");
int len = doFinal(context, output, output.position(), output.remaining());
output.position(output.position() + len);
return len;
}
/** Forcibly clean the context. */
public void clean() {
if (context != 0) {
clean(context);
context = 0;
}
}
/** Check whether context is initialized. */
private void checkState() {
Preconditions.checkState(context != 0);
}
@Override
protected void finalize() throws Throwable {
clean();
}
private native static void initIDs();
private native static long initContext(int alg, int padding);
private native long init(long context, int mode, int alg, int padding,
byte[] key, byte[] iv);
private native int update(long context, ByteBuffer input, int inputOffset,
int inputLength, ByteBuffer output, int outputOffset, int maxOutputLength);
private native int doFinal(long context, ByteBuffer output, int offset,
int maxOutputLength);
private native void clean(long context);
public native static String getLibraryName();
}