java/com/google/security/wycheproof/testcases/AesGcmTest.java - platform/external/wycheproof - Gitiles

 /**
  * @license
  * Copyright 2016 Google Inc. All rights reserved.
  * Licensed 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 com.google.security.wycheproof;

 import java.nio.ByteBuffer;
 import java.security.AlgorithmParameterGenerator;
 import java.security.AlgorithmParameters;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
 import java.security.Security;
 import javax.crypto.Cipher;
 import javax.crypto.ShortBufferException;
 import javax.crypto.spec.GCMParameterSpec;
 import javax.crypto.spec.IvParameterSpec;
 import javax.crypto.spec.SecretKeySpec;
 import junit.framework.TestCase;

 // TODO(bleichen):
 //   - For EAX I was able to derive some special cases by inverting OMAC.
 //     Not sure if that is possible here.
 //   - Gcm used to skip the tag verification in BouncyCastle when using ByteBuffers.
 //     test this.
 //   - Other Bytebuffer tests: Buffers with offset, Readonly buffers
 //   - The SUNJce provider requires tags that are at least 96 bits long.
 //     It would make sense to require this for all providers and add a test.
 //   - conscrypt only allows 12 byte IVs.
 /**
  * Testing AES-GCM
  *
  * <p>Other tests using AES-GCM are: CipherInputStreamTest.java CipherOuputStreamTest.java
  */
 public class AesGcmTest extends TestCase {

   /** Test vectors */
   public static class GcmTestVector {
     final byte[] pt;
     final byte[] aad;
     final byte[] ct;
     final String ptHex;
     final String ctHex;
     final GCMParameterSpec parameters;
     final SecretKeySpec key;

     public GcmTestVector(
         String message,
         String keyMaterial,
         String nonce,
         String aad,
         String ciphertext,
         String tag) {
       this.ptHex = message;
       this.pt = TestUtil.hexToBytes(message);
       this.aad = TestUtil.hexToBytes(aad);
       this.ct = TestUtil.hexToBytes(ciphertext + tag);
       this.ctHex = ciphertext + tag;
       int tagLength = 4 * tag.length();
       this.parameters = new GCMParameterSpec(tagLength, TestUtil.hexToBytes(nonce));
       this.key = new SecretKeySpec(TestUtil.hexToBytes(keyMaterial), "AES");
     }
   };

   // default, used for BouncyCastle
   private static final GcmTestVector[] DEFAULT_GCM_TEST_VECTORS = {
     new GcmTestVector(
         "001d0c231287c1182784554ca3a21908",
         "5b9604fe14eadba931b0ccf34843dab9",
         "028318abc1824029138141a2",
         "",
         "26073cc1d851beff176384dc9896d5ff",
         "0a3ea7a5487cb5f7d70fb6c58d038554"),
     new GcmTestVector(
         "001d0c231287c1182784554ca3a21908",
         "5b9604fe14eadba931b0ccf34843dab9",
         "921d2507fa8007b7bd067d34",
         "00112233445566778899aabbccddeeff",
         "49d8b9783e911913d87094d1f63cc765",
         "1e348ba07cca2cf04c618cb4"),
     new GcmTestVector(
         "2035af313d1346ab00154fea78322105",
         "aa023d0478dcb2b2312498293d9a9129",
         "0432bc49ac34412081288127",
         "aac39231129872a2",
         "eea945f3d0f98cc0fbab472a0cf24e87",
         "4bb9b4812519dadf9e1232016d068133"),
     new GcmTestVector(
         "2035af313d1346ab00154fea78322105",
         "aa023d0478dcb2b2312498293d9a9129",
         "0432bc49ac344120",
         "aac39231129872a2",
         "64c36bb3b732034e3a7d04efc5197785",
         "b7d0dd70b00d65b97cfd080ff4b819d1"),
   };

   // Conscrypt doesn't support 8-byte nonces
   private static final GcmTestVector[] OPENSSL_PROVIDER_GCM_TEST_VECTORS = {
     new GcmTestVector(
         "001d0c231287c1182784554ca3a21908",
         "5b9604fe14eadba931b0ccf34843dab9",
         "028318abc1824029138141a2",
         "",
         "26073cc1d851beff176384dc9896d5ff",
         "0a3ea7a5487cb5f7d70fb6c58d038554"),
     new GcmTestVector(
         "001d0c231287c1182784554ca3a21908",
         "5b9604fe14eadba931b0ccf34843dab9",
         "921d2507fa8007b7bd067d34",
         "00112233445566778899aabbccddeeff",
         "49d8b9783e911913d87094d1f63cc765",
         "1e348ba07cca2cf0"),
     new GcmTestVector(
         "2035af313d1346ab00154fea78322105",
         "aa023d0478dcb2b2312498293d9a9129",
         "0432bc49ac34412081288127",
         "aac39231129872a2",
         "eea945f3d0f98cc0fbab472a0cf24e87",
         "4bb9b4812519dadf9e1232016d068133"),
   };

   // SunJCE doesn't support 8-byte tags
   private static final GcmTestVector[] SUNJCE_PROVIDER_GCM_TEST_VECTORS = {
     new GcmTestVector(
         "001d0c231287c1182784554ca3a21908",
         "5b9604fe14eadba931b0ccf34843dab9",
         "028318abc1824029138141a2",
         "",
         "26073cc1d851beff176384dc9896d5ff",
         "0a3ea7a5487cb5f7d70fb6c58d038554"),
     new GcmTestVector(
         "2035af313d1346ab00154fea78322105",
         "aa023d0478dcb2b2312498293d9a9129",
         "0432bc49ac34412081288127",
         "aac39231129872a2",
         "eea945f3d0f98cc0fbab472a0cf24e87",
         "4bb9b4812519dadf9e1232016d068133"),
     new GcmTestVector(
         "2035af313d1346ab00154fea78322105",
         "aa023d0478dcb2b2312498293d9a9129",
         "0432bc49ac344120",
         "aac39231129872a2",
         "64c36bb3b732034e3a7d04efc5197785",
         "b7d0dd70b00d65b97cfd080ff4b819d1"),
   };

   private GcmTestVector[] getTestVectors() {
     GcmTestVector[] gcmTestVectors = DEFAULT_GCM_TEST_VECTORS;
     if (Security.getProvider("AndroidOpenSSL") != null) {
       gcmTestVectors = OPENSSL_PROVIDER_GCM_TEST_VECTORS;
     } else if (Security.getProvider("SunJCE") != null) {
       gcmTestVectors = SUNJCE_PROVIDER_GCM_TEST_VECTORS;
     }
     return gcmTestVectors;
   }

   public void testVectors() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       cipher.updateAAD(test.aad);
       byte[] ct = cipher.doFinal(test.pt);
       assertEquals(test.ctHex, TestUtil.bytesToHex(ct));
     }
   }

   /**
    * Typically one should always call updateAAD before any call to update. This test checks what
    * happens if the order is reversed. The test expects that a correct implementation either
    * computes the tag correctly or throws an exception.
    *
    * <p>For example, OpenJdk did compute incorrect tags in this case. The bug has been fixed in
    * http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/rev/89c06ca1e6cc
    *
    * <p>For example BouncyCastle computes correct tags if the calls are reversed, SunJCE and OpenJdk
    * now throw exceptions.
    */
   public void testLateUpdateAAD() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       byte[] c0 = cipher.update(test.pt);
       try {
         cipher.updateAAD(test.aad);
       } catch (java.lang.IllegalStateException ex) {
         // Throwing an exception is valid behaviour.
         continue;
       }
       byte[] c1 = cipher.doFinal();
       String result = TestUtil.bytesToHex(c0) + TestUtil.bytesToHex(c1);
       assertEquals(test.ctHex, result);
     }
   }

   /** Encryption with ByteBuffers. */
   public void testByteBuffer() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       // Encryption
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       ByteBuffer ptBuffer = ByteBuffer.wrap(test.pt);
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       int outputSize = cipher.getOutputSize(test.pt.length);
       ByteBuffer ctBuffer = ByteBuffer.allocate(outputSize);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ptBuffer, ctBuffer);
       assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));

       // Decryption
       ctBuffer.flip();
       cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
       outputSize = cipher.getOutputSize(test.ct.length);
       ByteBuffer decrypted = ByteBuffer.allocate(outputSize);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ctBuffer, decrypted);
       assertEquals(test.ptHex, TestUtil.byteBufferToHex(decrypted));
     }
   }

   /** Encryption with ByteBuffers should be copy-safe. */
   public void testByteBufferAlias() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       // Encryption
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       int outputSize = cipher.getOutputSize(test.pt.length);
       byte[] backingArray = new byte[outputSize];
       ByteBuffer ptBuffer = ByteBuffer.wrap(backingArray);
       ptBuffer.put(test.pt);
       ptBuffer.flip();
       ByteBuffer ctBuffer = ByteBuffer.wrap(backingArray);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ptBuffer, ctBuffer);
       assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));

       // Decryption
       ByteBuffer decrypted = ByteBuffer.wrap(backingArray);
       ctBuffer.flip();
       cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ctBuffer, decrypted);
       assertEquals(test.ptHex, TestUtil.byteBufferToHex(decrypted));
     }
   }

   public void testReadOnlyByteBuffer() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       // Encryption
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       ByteBuffer ptBuffer = ByteBuffer.wrap(test.pt).asReadOnlyBuffer();
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       int outputSize = cipher.getOutputSize(test.pt.length);
       ByteBuffer ctBuffer = ByteBuffer.allocate(outputSize);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ptBuffer, ctBuffer);
       assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));

       // Decryption
       ctBuffer.flip();
       ctBuffer = ctBuffer.asReadOnlyBuffer();
       cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
       outputSize = cipher.getOutputSize(test.ct.length);
       ByteBuffer decrypted = ByteBuffer.allocate(outputSize);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ctBuffer, decrypted);
       assertEquals(test.ptHex, TestUtil.byteBufferToHex(decrypted));
     }
   }

   /**
    * If a ByteBuffer is backed by an array and not readonly, then it is possible to access the data
    * through the .array() method. An implementation using this possiblity must ensure that it
    * considers the offset.
    */
   public void testByteBufferWithOffset() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       // Encryption
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       ByteBuffer ptBuffer = ByteBuffer.wrap(new byte[test.pt.length + 50]);
       ptBuffer.position(5);
       ptBuffer = ptBuffer.slice();
       ptBuffer.put(test.pt);
       ptBuffer.flip();

       ByteBuffer ctBuffer = ByteBuffer.wrap(new byte[test.ct.length + 50]);
       ctBuffer.position(8);
       ctBuffer = ctBuffer.slice();
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ptBuffer, ctBuffer);
       assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));
       ctBuffer.flip();

       // Decryption
       ByteBuffer decBuffer = ByteBuffer.wrap(new byte[test.pt.length + 50]);
       decBuffer.position(6);
       decBuffer = decBuffer.slice();
       cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
       cipher.updateAAD(test.aad);
       cipher.doFinal(ctBuffer, decBuffer);
       assertEquals(test.ptHex, TestUtil.byteBufferToHex(decBuffer));
     }
   }

   public void testByteBufferTooShort() throws Exception {
     GcmTestVector[] gcmTestVectors = getTestVectors();
     for (GcmTestVector test : gcmTestVectors) {
       // Encryption
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
       ByteBuffer ptBuffer = ByteBuffer.wrap(test.pt);
       ByteBuffer ctBuffer = ByteBuffer.allocate(test.ct.length - 1);
       cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
       cipher.updateAAD(test.aad);
       try {
         cipher.doFinal(ptBuffer, ctBuffer);
         fail("This should not work");
       } catch (ShortBufferException ex) {
         // expected
       }

       // Decryption
       ctBuffer = ByteBuffer.wrap(test.ct);
       ByteBuffer decrypted = ByteBuffer.allocate(test.pt.length - 1);
       cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
       cipher.updateAAD(test.aad);
       try {
         cipher.doFinal(ctBuffer, decrypted);
         fail("This should not work");
       } catch (ShortBufferException ex) {
         // expected
       }
     }
   }

   /**
    * The default authentication tag size should be 128-bit by default for the following reasons:
    * <br>
    * (1) Security: Ferguson, N., Authentication Weaknesses in GCM, Natl. Inst. Stand. Technol. [Web
    * page], http://www.csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/
    * CWC-GCM/Ferguson2.pdf, May 20, 2005. This paper points out that a n-bit tag has lower strength
    * than expected. <br>
    * (2) Compatibility: Assume an implementer tests some code using one provider than switches to
    * another provider. Such a switch should ideally not lower the security. <br>
    * Conscrypt used to have only 12-byte authentication tag (b/26186727).
    */
   public void testDefaultTagSizeIvParameterSpec() throws Exception {
     byte[] counter = new byte[12];
     byte[] input = new byte[16];
     byte[] key = new byte[16];
     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
     try {
       cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), new IvParameterSpec(counter));
     } catch (InvalidAlgorithmParameterException ex) {
       // OpenJDK8 does not support IvParameterSpec for GCM.
       System.out.println(ex);
       return;
     }
     byte[] output = cipher.doFinal(input);
     assertEquals(input.length + 16, output.length);
   }

   /**
    * The default authentication tag size should be 128-bit by default for the following reasons:
    * <br>
    * (1) Security: Ferguson, N., Authentication Weaknesses in GCM, Natl. Inst. Stand. Technol. [Web
    * page], http://www.csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/
    * CWC-GCM/Ferguson2.pdf, May 20, 2005. This paper points out that a n-bit tag has lower strength
    * than expected. <br>
    * (2) Compatibility: Assume an implementer tests some code using one provider than switches to
    * another provider. Such a switch should ideally not lower the security. <br>
    * BouncyCastle used to have only 12-byte authentication tag (b/26186727).
    */
   public void testDefaultTagSizeAlgorithmParameterGenerator() throws Exception {
     byte[] input = new byte[10];
     byte[] key = new byte[16];
     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
     try {
       AlgorithmParameterGenerator.getInstance("GCM");
     } catch (NoSuchAlgorithmException ex) {
       // Conscrypt does not support AlgorithmParameterGenerator for GCM.
       System.out.println(ex);
       return;
     }
     AlgorithmParameters param = AlgorithmParameterGenerator.getInstance("GCM").generateParameters();
     cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), param);
     byte[] output = cipher.doFinal(input);
     assertEquals(input.length + 16, output.length);
   }
 }
	/**
	* @license
	* Copyright 2016 Google Inc. All rights reserved.
	* Licensed 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 com.google.security.wycheproof;

	import java.nio.ByteBuffer;
	import java.security.AlgorithmParameterGenerator;
	import java.security.AlgorithmParameters;
	import java.security.InvalidAlgorithmParameterException;
	import java.security.NoSuchAlgorithmException;
	import java.security.Security;
	import javax.crypto.Cipher;
	import javax.crypto.ShortBufferException;
	import javax.crypto.spec.GCMParameterSpec;
	import javax.crypto.spec.IvParameterSpec;
	import javax.crypto.spec.SecretKeySpec;
	import junit.framework.TestCase;

	// TODO(bleichen):
	// - For EAX I was able to derive some special cases by inverting OMAC.
	// Not sure if that is possible here.
	// - Gcm used to skip the tag verification in BouncyCastle when using ByteBuffers.
	// test this.
	// - Other Bytebuffer tests: Buffers with offset, Readonly buffers
	// - The SUNJce provider requires tags that are at least 96 bits long.
	// It would make sense to require this for all providers and add a test.
	// - conscrypt only allows 12 byte IVs.
	/**
	* Testing AES-GCM
	*
	* <p>Other tests using AES-GCM are: CipherInputStreamTest.java CipherOuputStreamTest.java
	*/
	public class AesGcmTest extends TestCase {

	/** Test vectors */
	public static class GcmTestVector {
	final byte[] pt;
	final byte[] aad;
	final byte[] ct;
	final String ptHex;
	final String ctHex;
	final GCMParameterSpec parameters;
	final SecretKeySpec key;

	public GcmTestVector(
	String message,
	String keyMaterial,
	String nonce,
	String aad,
	String ciphertext,
	String tag) {
	this.ptHex = message;
	this.pt = TestUtil.hexToBytes(message);
	this.aad = TestUtil.hexToBytes(aad);
	this.ct = TestUtil.hexToBytes(ciphertext + tag);
	this.ctHex = ciphertext + tag;
	int tagLength = 4 * tag.length();
	this.parameters = new GCMParameterSpec(tagLength, TestUtil.hexToBytes(nonce));
	this.key = new SecretKeySpec(TestUtil.hexToBytes(keyMaterial), "AES");
	}
	};

	// default, used for BouncyCastle
	private static final GcmTestVector[] DEFAULT_GCM_TEST_VECTORS = {
	new GcmTestVector(
	"001d0c231287c1182784554ca3a21908",
	"5b9604fe14eadba931b0ccf34843dab9",
	"028318abc1824029138141a2",
	"",
	"26073cc1d851beff176384dc9896d5ff",
	"0a3ea7a5487cb5f7d70fb6c58d038554"),
	new GcmTestVector(
	"001d0c231287c1182784554ca3a21908",
	"5b9604fe14eadba931b0ccf34843dab9",
	"921d2507fa8007b7bd067d34",
	"00112233445566778899aabbccddeeff",
	"49d8b9783e911913d87094d1f63cc765",
	"1e348ba07cca2cf04c618cb4"),
	new GcmTestVector(
	"2035af313d1346ab00154fea78322105",
	"aa023d0478dcb2b2312498293d9a9129",
	"0432bc49ac34412081288127",
	"aac39231129872a2",
	"eea945f3d0f98cc0fbab472a0cf24e87",
	"4bb9b4812519dadf9e1232016d068133"),
	new GcmTestVector(
	"2035af313d1346ab00154fea78322105",
	"aa023d0478dcb2b2312498293d9a9129",
	"0432bc49ac344120",
	"aac39231129872a2",
	"64c36bb3b732034e3a7d04efc5197785",
	"b7d0dd70b00d65b97cfd080ff4b819d1"),
	};

	// Conscrypt doesn't support 8-byte nonces
	private static final GcmTestVector[] OPENSSL_PROVIDER_GCM_TEST_VECTORS = {
	new GcmTestVector(
	"001d0c231287c1182784554ca3a21908",
	"5b9604fe14eadba931b0ccf34843dab9",
	"028318abc1824029138141a2",
	"",
	"26073cc1d851beff176384dc9896d5ff",
	"0a3ea7a5487cb5f7d70fb6c58d038554"),
	new GcmTestVector(
	"001d0c231287c1182784554ca3a21908",
	"5b9604fe14eadba931b0ccf34843dab9",
	"921d2507fa8007b7bd067d34",
	"00112233445566778899aabbccddeeff",
	"49d8b9783e911913d87094d1f63cc765",
	"1e348ba07cca2cf0"),
	new GcmTestVector(
	"2035af313d1346ab00154fea78322105",
	"aa023d0478dcb2b2312498293d9a9129",
	"0432bc49ac34412081288127",
	"aac39231129872a2",
	"eea945f3d0f98cc0fbab472a0cf24e87",
	"4bb9b4812519dadf9e1232016d068133"),
	};

	// SunJCE doesn't support 8-byte tags
	private static final GcmTestVector[] SUNJCE_PROVIDER_GCM_TEST_VECTORS = {
	new GcmTestVector(
	"001d0c231287c1182784554ca3a21908",
	"5b9604fe14eadba931b0ccf34843dab9",
	"028318abc1824029138141a2",
	"",
	"26073cc1d851beff176384dc9896d5ff",
	"0a3ea7a5487cb5f7d70fb6c58d038554"),
	new GcmTestVector(
	"2035af313d1346ab00154fea78322105",
	"aa023d0478dcb2b2312498293d9a9129",
	"0432bc49ac34412081288127",
	"aac39231129872a2",
	"eea945f3d0f98cc0fbab472a0cf24e87",
	"4bb9b4812519dadf9e1232016d068133"),
	new GcmTestVector(
	"2035af313d1346ab00154fea78322105",
	"aa023d0478dcb2b2312498293d9a9129",
	"0432bc49ac344120",
	"aac39231129872a2",
	"64c36bb3b732034e3a7d04efc5197785",
	"b7d0dd70b00d65b97cfd080ff4b819d1"),
	};

	private GcmTestVector[] getTestVectors() {
	GcmTestVector[] gcmTestVectors = DEFAULT_GCM_TEST_VECTORS;
	if (Security.getProvider("AndroidOpenSSL") != null) {
	gcmTestVectors = OPENSSL_PROVIDER_GCM_TEST_VECTORS;
	} else if (Security.getProvider("SunJCE") != null) {
	gcmTestVectors = SUNJCE_PROVIDER_GCM_TEST_VECTORS;
	}
	return gcmTestVectors;
	}

	public void testVectors() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	cipher.updateAAD(test.aad);
	byte[] ct = cipher.doFinal(test.pt);
	assertEquals(test.ctHex, TestUtil.bytesToHex(ct));
	}
	}

	/**
	* Typically one should always call updateAAD before any call to update. This test checks what
	* happens if the order is reversed. The test expects that a correct implementation either
	* computes the tag correctly or throws an exception.
	*
	* <p>For example, OpenJdk did compute incorrect tags in this case. The bug has been fixed in
	* http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/rev/89c06ca1e6cc
	*
	* <p>For example BouncyCastle computes correct tags if the calls are reversed, SunJCE and OpenJdk
	* now throw exceptions.
	*/
	public void testLateUpdateAAD() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	byte[] c0 = cipher.update(test.pt);
	try {
	cipher.updateAAD(test.aad);
	} catch (java.lang.IllegalStateException ex) {
	// Throwing an exception is valid behaviour.
	continue;
	}
	byte[] c1 = cipher.doFinal();
	String result = TestUtil.bytesToHex(c0) + TestUtil.bytesToHex(c1);
	assertEquals(test.ctHex, result);
	}
	}

	/** Encryption with ByteBuffers. */
	public void testByteBuffer() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	// Encryption
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	ByteBuffer ptBuffer = ByteBuffer.wrap(test.pt);
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	int outputSize = cipher.getOutputSize(test.pt.length);
	ByteBuffer ctBuffer = ByteBuffer.allocate(outputSize);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ptBuffer, ctBuffer);
	assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));

	// Decryption
	ctBuffer.flip();
	cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
	outputSize = cipher.getOutputSize(test.ct.length);
	ByteBuffer decrypted = ByteBuffer.allocate(outputSize);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ctBuffer, decrypted);
	assertEquals(test.ptHex, TestUtil.byteBufferToHex(decrypted));
	}
	}

	/** Encryption with ByteBuffers should be copy-safe. */
	public void testByteBufferAlias() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	// Encryption
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	int outputSize = cipher.getOutputSize(test.pt.length);
	byte[] backingArray = new byte[outputSize];
	ByteBuffer ptBuffer = ByteBuffer.wrap(backingArray);
	ptBuffer.put(test.pt);
	ptBuffer.flip();
	ByteBuffer ctBuffer = ByteBuffer.wrap(backingArray);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ptBuffer, ctBuffer);
	assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));

	// Decryption
	ByteBuffer decrypted = ByteBuffer.wrap(backingArray);
	ctBuffer.flip();
	cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ctBuffer, decrypted);
	assertEquals(test.ptHex, TestUtil.byteBufferToHex(decrypted));
	}
	}

	public void testReadOnlyByteBuffer() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	// Encryption
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	ByteBuffer ptBuffer = ByteBuffer.wrap(test.pt).asReadOnlyBuffer();
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	int outputSize = cipher.getOutputSize(test.pt.length);
	ByteBuffer ctBuffer = ByteBuffer.allocate(outputSize);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ptBuffer, ctBuffer);
	assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));

	// Decryption
	ctBuffer.flip();
	ctBuffer = ctBuffer.asReadOnlyBuffer();
	cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
	outputSize = cipher.getOutputSize(test.ct.length);
	ByteBuffer decrypted = ByteBuffer.allocate(outputSize);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ctBuffer, decrypted);
	assertEquals(test.ptHex, TestUtil.byteBufferToHex(decrypted));
	}
	}

	/**
	* If a ByteBuffer is backed by an array and not readonly, then it is possible to access the data
	* through the .array() method. An implementation using this possiblity must ensure that it
	* considers the offset.
	*/
	public void testByteBufferWithOffset() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	// Encryption
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	ByteBuffer ptBuffer = ByteBuffer.wrap(new byte[test.pt.length + 50]);
	ptBuffer.position(5);
	ptBuffer = ptBuffer.slice();
	ptBuffer.put(test.pt);
	ptBuffer.flip();

	ByteBuffer ctBuffer = ByteBuffer.wrap(new byte[test.ct.length + 50]);
	ctBuffer.position(8);
	ctBuffer = ctBuffer.slice();
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ptBuffer, ctBuffer);
	assertEquals(test.ctHex, TestUtil.byteBufferToHex(ctBuffer));
	ctBuffer.flip();

	// Decryption
	ByteBuffer decBuffer = ByteBuffer.wrap(new byte[test.pt.length + 50]);
	decBuffer.position(6);
	decBuffer = decBuffer.slice();
	cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
	cipher.updateAAD(test.aad);
	cipher.doFinal(ctBuffer, decBuffer);
	assertEquals(test.ptHex, TestUtil.byteBufferToHex(decBuffer));
	}
	}

	public void testByteBufferTooShort() throws Exception {
	GcmTestVector[] gcmTestVectors = getTestVectors();
	for (GcmTestVector test : gcmTestVectors) {
	// Encryption
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	ByteBuffer ptBuffer = ByteBuffer.wrap(test.pt);
	ByteBuffer ctBuffer = ByteBuffer.allocate(test.ct.length - 1);
	cipher.init(Cipher.ENCRYPT_MODE, test.key, test.parameters);
	cipher.updateAAD(test.aad);
	try {
	cipher.doFinal(ptBuffer, ctBuffer);
	fail("This should not work");
	} catch (ShortBufferException ex) {
	// expected
	}

	// Decryption
	ctBuffer = ByteBuffer.wrap(test.ct);
	ByteBuffer decrypted = ByteBuffer.allocate(test.pt.length - 1);
	cipher.init(Cipher.DECRYPT_MODE, test.key, test.parameters);
	cipher.updateAAD(test.aad);
	try {
	cipher.doFinal(ctBuffer, decrypted);
	fail("This should not work");
	} catch (ShortBufferException ex) {
	// expected
	}
	}
	}

	/**
	* The default authentication tag size should be 128-bit by default for the following reasons:
	* <br>
	* (1) Security: Ferguson, N., Authentication Weaknesses in GCM, Natl. Inst. Stand. Technol. [Web
	* page], http://www.csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/
	* CWC-GCM/Ferguson2.pdf, May 20, 2005. This paper points out that a n-bit tag has lower strength
	* than expected. <br>
	* (2) Compatibility: Assume an implementer tests some code using one provider than switches to
	* another provider. Such a switch should ideally not lower the security. <br>
	* Conscrypt used to have only 12-byte authentication tag (b/26186727).
	*/
	public void testDefaultTagSizeIvParameterSpec() throws Exception {
	byte[] counter = new byte[12];
	byte[] input = new byte[16];
	byte[] key = new byte[16];
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	try {
	cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), new IvParameterSpec(counter));
	} catch (InvalidAlgorithmParameterException ex) {
	// OpenJDK8 does not support IvParameterSpec for GCM.
	System.out.println(ex);
	return;
	}
	byte[] output = cipher.doFinal(input);
	assertEquals(input.length + 16, output.length);
	}

	/**
	* The default authentication tag size should be 128-bit by default for the following reasons:
	* <br>
	* (1) Security: Ferguson, N., Authentication Weaknesses in GCM, Natl. Inst. Stand. Technol. [Web
	* page], http://www.csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/
	* CWC-GCM/Ferguson2.pdf, May 20, 2005. This paper points out that a n-bit tag has lower strength
	* than expected. <br>
	* (2) Compatibility: Assume an implementer tests some code using one provider than switches to
	* another provider. Such a switch should ideally not lower the security. <br>
	* BouncyCastle used to have only 12-byte authentication tag (b/26186727).
	*/
	public void testDefaultTagSizeAlgorithmParameterGenerator() throws Exception {
	byte[] input = new byte[10];
	byte[] key = new byte[16];
	Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
	try {
	AlgorithmParameterGenerator.getInstance("GCM");
	} catch (NoSuchAlgorithmException ex) {
	// Conscrypt does not support AlgorithmParameterGenerator for GCM.
	System.out.println(ex);
	return;
	}
	AlgorithmParameters param = AlgorithmParameterGenerator.getInstance("GCM").generateParameters();
	cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), param);
	byte[] output = cipher.doFinal(input);
	assertEquals(input.length + 16, output.length);
	}
	}