Remove Unnecessary Backwards Compatability

Since this is going to be merged into Spring Security 7 (a major release) and AESFastEngine is deprecated,
we should no longer support it (as it will likely be removed from Bouncy Castle)

crypto/src/main/java/org/springframework/security/crypto/encrypt/BouncyCastleAesCbcBytesEncryptor.java

@@ -16,12 +16,9 @@
 
 package org.springframework.security.crypto.encrypt;
 
-import java.util.function.Supplier;
-
 import org.bouncycastle.crypto.BufferedBlockCipher;
 import org.bouncycastle.crypto.InvalidCipherTextException;
 import org.bouncycastle.crypto.engines.AESEngine;
-import org.bouncycastle.crypto.engines.AESFastEngine;
 import org.bouncycastle.crypto.modes.CBCBlockCipher;
 import org.bouncycastle.crypto.modes.CBCModeCipher;
 import org.bouncycastle.crypto.paddings.PKCS7Padding;
@@ -41,8 +38,6 @@ import org.springframework.security.crypto.util.EncodingUtils;
  */
 public class BouncyCastleAesCbcBytesEncryptor extends BouncyCastleAesBytesEncryptor {
 
-	private Supplier<CBCModeCipher> cipherFactory = () -> CBCBlockCipher.newInstance(AESEngine.newInstance());
-
 	public BouncyCastleAesCbcBytesEncryptor(String password, CharSequence salt) {
 		super(password, salt);
 	}
@@ -54,8 +49,8 @@ public class BouncyCastleAesCbcBytesEncryptor extends BouncyCastleAesBytesEncryp
 	@Override
 	public byte[] encrypt(byte[] bytes) {
 		byte[] iv = this.ivGenerator.generateKey();
-		PaddedBufferedBlockCipher blockCipher = new PaddedBufferedBlockCipher(this.cipherFactory.get(),
-				new PKCS7Padding());
+		CBCModeCipher cbcModeCipher = CBCBlockCipher.newInstance(AESEngine.newInstance());
+		PaddedBufferedBlockCipher blockCipher = new PaddedBufferedBlockCipher(cbcModeCipher, new PKCS7Padding());
 		blockCipher.init(true, new ParametersWithIV(this.secretKey, iv));
 		byte[] encrypted = process(blockCipher, bytes);
 		return (iv != null) ? EncodingUtils.concatenate(iv, encrypted) : encrypted;
@@ -63,10 +58,10 @@ public class BouncyCastleAesCbcBytesEncryptor extends BouncyCastleAesBytesEncryp
 
 	@Override
 	public byte[] decrypt(byte[] encryptedBytes) {
+		CBCModeCipher cbcModeCipher = CBCBlockCipher.newInstance(AESEngine.newInstance());
 		byte[] iv = EncodingUtils.subArray(encryptedBytes, 0, this.ivGenerator.getKeyLength());
 		encryptedBytes = EncodingUtils.subArray(encryptedBytes, this.ivGenerator.getKeyLength(), encryptedBytes.length);
-		PaddedBufferedBlockCipher blockCipher = new PaddedBufferedBlockCipher(this.cipherFactory.get(),
-				new PKCS7Padding());
+		PaddedBufferedBlockCipher blockCipher = new PaddedBufferedBlockCipher(cbcModeCipher, new PKCS7Padding());
 		blockCipher.init(false, new ParametersWithIV(this.secretKey, iv));
 		return process(blockCipher, encryptedBytes);
 	}
@@ -88,17 +83,4 @@ public class BouncyCastleAesCbcBytesEncryptor extends BouncyCastleAesBytesEncryp
 		return out;
 	}
 
-	/**
-	 * Used to test compatibility with deprecated {@link AESFastEngine}.
-	 */
-	@SuppressWarnings("deprecation")
-	static BouncyCastleAesCbcBytesEncryptor withAESFastEngine(String password, CharSequence salt,
-			BytesKeyGenerator ivGenerator) {
-		BouncyCastleAesCbcBytesEncryptor bytesEncryptor = new BouncyCastleAesCbcBytesEncryptor(password, salt,
-				ivGenerator);
-		bytesEncryptor.cipherFactory = () -> new CBCBlockCipher(new AESFastEngine());
-
-		return bytesEncryptor;
-	}
-
 }

crypto/src/main/java/org/springframework/security/crypto/encrypt/BouncyCastleAesGcmBytesEncryptor.java

@@ -16,11 +16,8 @@
 
 package org.springframework.security.crypto.encrypt;
 
-import java.util.function.Supplier;
-
 import org.bouncycastle.crypto.InvalidCipherTextException;
 import org.bouncycastle.crypto.engines.AESEngine;
-import org.bouncycastle.crypto.engines.AESFastEngine;
 import org.bouncycastle.crypto.modes.AEADBlockCipher;
 import org.bouncycastle.crypto.modes.GCMBlockCipher;
 import org.bouncycastle.crypto.params.AEADParameters;
@@ -39,9 +36,6 @@ import org.springframework.security.crypto.util.EncodingUtils;
  */
 public class BouncyCastleAesGcmBytesEncryptor extends BouncyCastleAesBytesEncryptor {
 
-	private Supplier<GCMBlockCipher> cipherFactory = () -> (GCMBlockCipher) GCMBlockCipher
-		.newInstance(AESEngine.newInstance());
-
 	public BouncyCastleAesGcmBytesEncryptor(String password, CharSequence salt) {
 		super(password, salt);
 	}
@@ -53,7 +47,7 @@ public class BouncyCastleAesGcmBytesEncryptor extends BouncyCastleAesBytesEncryp
 	@Override
 	public byte[] encrypt(byte[] bytes) {
 		byte[] iv = this.ivGenerator.generateKey();
-		AEADBlockCipher blockCipher = this.cipherFactory.get();
+		AEADBlockCipher blockCipher = GCMBlockCipher.newInstance(AESEngine.newInstance());
 		blockCipher.init(true, new AEADParameters(this.secretKey, 128, iv, null));
 		byte[] encrypted = process(blockCipher, bytes);
 		return (iv != null) ? EncodingUtils.concatenate(iv, encrypted) : encrypted;
@@ -63,7 +57,7 @@ public class BouncyCastleAesGcmBytesEncryptor extends BouncyCastleAesBytesEncryp
 	public byte[] decrypt(byte[] encryptedBytes) {
 		byte[] iv = EncodingUtils.subArray(encryptedBytes, 0, this.ivGenerator.getKeyLength());
 		encryptedBytes = EncodingUtils.subArray(encryptedBytes, this.ivGenerator.getKeyLength(), encryptedBytes.length);
-		AEADBlockCipher blockCipher = this.cipherFactory.get();
+		AEADBlockCipher blockCipher = GCMBlockCipher.newInstance(AESEngine.newInstance());
 		blockCipher.init(false, new AEADParameters(this.secretKey, 128, iv, null));
 		return process(blockCipher, encryptedBytes);
 	}
@@ -85,17 +79,4 @@ public class BouncyCastleAesGcmBytesEncryptor extends BouncyCastleAesBytesEncryp
 		return out;
 	}
 
-	/**
-	 * Used to test compatibility with deprecated {@link AESFastEngine}.
-	 */
-	@SuppressWarnings("deprecation")
-	static BouncyCastleAesGcmBytesEncryptor withAESFastEngine(String password, CharSequence salt,
-			BytesKeyGenerator ivGenerator) {
-		BouncyCastleAesGcmBytesEncryptor bytesEncryptor = new BouncyCastleAesGcmBytesEncryptor(password, salt,
-				ivGenerator);
-		bytesEncryptor.cipherFactory = () -> new GCMBlockCipher(new AESFastEngine());
-
-		return bytesEncryptor;
-	}
-
 }

crypto/src/test/java/org/springframework/security/crypto/encrypt/BouncyCastleAesBytesEncryptorEquivalencyTests.java

@@ -23,8 +23,6 @@ import java.util.Random;
 import java.util.UUID;
 
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
-import org.junit.jupiter.api.RepeatedTest;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.security.crypto.codec.Hex;
@@ -93,64 +91,6 @@ public class BouncyCastleAesBytesEncryptorEquivalencyTests {
 		testCompatibility(bcEncryptor, jceEncryptor);
 	}
 
-	@Test
-	public void bouncyCastleAesGcmWithAESFastEngineCompatible() throws Exception {
-		CryptoAssumptions.assumeGCMJCE();
-		BytesEncryptor fastEngineEncryptor = BouncyCastleAesGcmBytesEncryptor.withAESFastEngine(this.password,
-				this.salt, KeyGenerators.secureRandom(16));
-		BytesEncryptor defaultEngineEncryptor = new BouncyCastleAesGcmBytesEncryptor(this.password, this.salt,
-				KeyGenerators.secureRandom(16));
-		testCompatibility(fastEngineEncryptor, defaultEngineEncryptor);
-	}
-
-	@Test
-	public void bouncyCastleAesCbcWithAESFastEngineCompatible() throws Exception {
-		CryptoAssumptions.assumeCBCJCE();
-		BytesEncryptor fastEngineEncryptor = BouncyCastleAesCbcBytesEncryptor.withAESFastEngine(this.password,
-				this.salt, KeyGenerators.secureRandom(16));
-		BytesEncryptor defaultEngineEncryptor = new BouncyCastleAesCbcBytesEncryptor(this.password, this.salt,
-				KeyGenerators.secureRandom(16));
-		testCompatibility(fastEngineEncryptor, defaultEngineEncryptor);
-	}
-
-	/**
-	 * Comment out @Disabled below to compare relative speed of deprecated AESFastEngine
-	 * with the default AESEngine.
-	 */
-	@Disabled
-	@RepeatedTest(100)
-	public void bouncyCastleAesGcmWithAESFastEngineSpeedTest() throws Exception {
-		CryptoAssumptions.assumeGCMJCE();
-		BytesEncryptor defaultEngineEncryptor = new BouncyCastleAesGcmBytesEncryptor(this.password, this.salt,
-				KeyGenerators.secureRandom(16));
-		BytesEncryptor fastEngineEncryptor = BouncyCastleAesGcmBytesEncryptor.withAESFastEngine(this.password,
-				this.salt, KeyGenerators.secureRandom(16));
-		long defaultNanos = testSpeed(defaultEngineEncryptor);
-		long fastNanos = testSpeed(fastEngineEncryptor);
-		System.out.println(nanosToReadableString("AES GCM w/Default Engine", defaultNanos));
-		System.out.println(nanosToReadableString("AES GCM w/   Fast Engine", fastNanos));
-		assertThat(fastNanos).isLessThan(defaultNanos);
-	}
-
-	/**
-	 * Comment out @Disabled below to compare relative speed of deprecated AESFastEngine
-	 * with the default AESEngine.
-	 */
-	@Disabled
-	@RepeatedTest(100)
-	public void bouncyCastleAesCbcWithAESFastEngineSpeedTest() throws Exception {
-		CryptoAssumptions.assumeCBCJCE();
-		BytesEncryptor defaultEngineEncryptor = new BouncyCastleAesCbcBytesEncryptor(this.password, this.salt,
-				KeyGenerators.secureRandom(16));
-		BytesEncryptor fastEngineEncryptor = BouncyCastleAesCbcBytesEncryptor.withAESFastEngine(this.password,
-				this.salt, KeyGenerators.secureRandom(16));
-		long defaultNanos = testSpeed(defaultEngineEncryptor);
-		long fastNanos = testSpeed(fastEngineEncryptor);
-		System.out.println(nanosToReadableString("AES CBC w/Default Engine", defaultNanos));
-		System.out.println(nanosToReadableString("AES CBC w/   Fast Engine", fastNanos));
-		assertThat(fastNanos).isLessThan(defaultNanos);
-	}
-
 	private void testEquivalence(BytesEncryptor left, BytesEncryptor right) {
 		for (int size = 1; size < 2048; size++) {
 			this.testData = new byte[size];