/*
* Copyright (C) 2012 The Android Open Source Project
*
* 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 org.conscrypt;
import java.io.IOException;
import java.security.AlgorithmParameters;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.InvalidParameterException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.InvalidParameterSpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Arrays;
import java.util.Locale;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.CipherSpi;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.ShortBufferException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.conscrypt.util.EmptyArray;
public abstract class OpenSSLCipher extends CipherSpi {
/**
* Modes that a block cipher may support.
*/
protected static enum Mode {
CBC,
CFB, CFB1, CFB8, CFB128,
CTR,
CTS,
ECB,
OFB, OFB64, OFB128,
PCBC,
}
/**
* Paddings that a block cipher may support.
*/
protected static enum Padding {
NOPADDING,
PKCS5PADDING,
ISO10126PADDING,
}
/**
* Native pointer for the OpenSSL EVP_CIPHER context.
*/
private OpenSSLCipherContext cipherCtx = new OpenSSLCipherContext(
NativeCrypto.EVP_CIPHER_CTX_new());
/**
* The current cipher mode.
*/
private Mode mode = Mode.ECB;
/**
* The current cipher padding.
*/
private Padding padding = Padding.PKCS5PADDING;
/**
* May be used when reseting the cipher instance after calling
* {@code doFinal}.
*/
private byte[] encodedKey;
/**
* The Initial Vector (IV) used for the current cipher.
*/
private byte[] iv;
/**
* Current cipher mode: encrypting or decrypting.
*/
private boolean encrypting;
/**
* The block size of the current cipher.
*/
private int blockSize;
/**
* The block size of the current mode.
*/
private int modeBlockSize;
/**
* Whether the cipher has processed any data yet. OpenSSL doesn't like
* calling "doFinal()" in decryption mode without processing any updates.
*/
private boolean calledUpdate;
protected OpenSSLCipher() {
}
protected OpenSSLCipher(Mode mode, Padding padding) {
this.mode = mode;
this.padding = padding;
blockSize = getCipherBlockSize();
}
/**
* Returns the standard name for the particular algorithm.
*/
protected abstract String getBaseCipherName();
/**
* Returns the OpenSSL cipher name for the particular {@code keySize} and
* cipher {@code mode}.
*/
protected abstract String getCipherName(int keySize, Mode mode);
/**
* Checks whether the cipher supports this particular {@code keySize} (in
* bytes) and throws {@code InvalidKeyException} if it doesn't.
*/
protected abstract void checkSupportedKeySize(int keySize) throws InvalidKeyException;
/**
* Checks whether the cipher supports this particular cipher {@code mode}
* and throws {@code NoSuchAlgorithmException} if it doesn't.
*/
protected abstract void checkSupportedMode(Mode mode) throws NoSuchAlgorithmException;
/**
* Checks whether the cipher supports this particular cipher {@code padding}
* and throws {@code NoSuchPaddingException} if it doesn't.
*/
protected abstract void checkSupportedPadding(Padding padding) throws NoSuchPaddingException;
protected abstract int getCipherBlockSize();
protected boolean supportsVariableSizeKey() {
return false;
}
@Override
protected void engineSetMode(String modeStr) throws NoSuchAlgorithmException {
final Mode mode;
try {
mode = Mode.valueOf(modeStr.toUpperCase(Locale.US));
} catch (IllegalArgumentException e) {
NoSuchAlgorithmException newE = new NoSuchAlgorithmException("No such mode: "
+ modeStr);
newE.initCause(e);
throw newE;
}
checkSupportedMode(mode);
this.mode = mode;
}
@Override
protected void engineSetPadding(String paddingStr) throws NoSuchPaddingException {
final String paddingStrUpper = paddingStr.toUpperCase(Locale.US);
final Padding padding;
try {
padding = Padding.valueOf(paddingStrUpper);
} catch (IllegalArgumentException e) {
NoSuchPaddingException newE = new NoSuchPaddingException("No such padding: "
+ paddingStr);
newE.initCause(e);
throw newE;
}
checkSupportedPadding(padding);
this.padding = padding;
}
@Override
protected int engineGetBlockSize() {
return blockSize;
}
/**
* The size of output if {@code doFinal()} is called with this
* {@code inputLen}. If padding is enabled and the size of the input puts it
* right at the block size, it will add another block for the padding.
*/
private int getOutputSize(int inputLen) {
if (modeBlockSize == 1) {
return inputLen;
} else {
final int buffered = NativeCrypto.get_EVP_CIPHER_CTX_buf_len(cipherCtx.getContext());
if (padding == Padding.NOPADDING) {
return buffered + inputLen;
} else {
final int totalLen = inputLen + buffered + modeBlockSize;
return totalLen - (totalLen % modeBlockSize);
}
}
}
@Override
protected int engineGetOutputSize(int inputLen) {
return getOutputSize(inputLen);
}
@Override
protected byte[] engineGetIV() {
return iv;
}
@Override
protected AlgorithmParameters engineGetParameters() {
if (iv != null && iv.length > 0) {
try {
AlgorithmParameters params = AlgorithmParameters.getInstance(getBaseCipherName());
params.init(iv);
return params;
} catch (NoSuchAlgorithmException e) {
return null;
} catch (IOException e) {
return null;
}
}
return null;
}
private void engineInitInternal(int opmode, Key key, byte[] iv, SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
if (opmode == Cipher.ENCRYPT_MODE || opmode == Cipher.WRAP_MODE) {
encrypting = true;
} else if (opmode == Cipher.DECRYPT_MODE || opmode == Cipher.UNWRAP_MODE) {
encrypting = false;
} else {
throw new InvalidParameterException("Unsupported opmode " + opmode);
}
if (!(key instanceof SecretKey)) {
throw new InvalidKeyException("Only SecretKey is supported");
}
final byte[] encodedKey = key.getEncoded();
if (encodedKey == null) {
throw new InvalidKeyException("key.getEncoded() == null");
}
checkSupportedKeySize(encodedKey.length);
this.encodedKey = encodedKey;
final long cipherType = NativeCrypto.EVP_get_cipherbyname(getCipherName(encodedKey.length,
mode));
if (cipherType == 0) {
throw new InvalidAlgorithmParameterException("Cannot find name for key length = "
+ (encodedKey.length * 8) + " and mode = " + mode);
}
final int ivLength = NativeCrypto.EVP_CIPHER_iv_length(cipherType);
if (iv == null && ivLength != 0) {
iv = new byte[ivLength];
if (encrypting) {
if (random == null) {
random = new SecureRandom();
}
random.nextBytes(iv);
}
} else if (iv != null && iv.length != ivLength) {
throw new InvalidAlgorithmParameterException("expected IV length of " + ivLength);
}
this.iv = iv;
if (supportsVariableSizeKey()) {
NativeCrypto.EVP_CipherInit_ex(cipherCtx.getContext(), cipherType, null, null,
encrypting);
NativeCrypto.EVP_CIPHER_CTX_set_key_length(cipherCtx.getContext(), encodedKey.length);
NativeCrypto.EVP_CipherInit_ex(cipherCtx.getContext(), 0, encodedKey, iv, encrypting);
} else {
NativeCrypto.EVP_CipherInit_ex(cipherCtx.getContext(), cipherType, encodedKey, iv,
encrypting);
}
// OpenSSL only supports PKCS5 Padding.
NativeCrypto.EVP_CIPHER_CTX_set_padding(cipherCtx.getContext(),
padding == Padding.PKCS5PADDING);
modeBlockSize = NativeCrypto.EVP_CIPHER_CTX_block_size(cipherCtx.getContext());
calledUpdate = false;
}
@Override
protected void engineInit(int opmode, Key key, SecureRandom random) throws InvalidKeyException {
try {
engineInitInternal(opmode, key, null, random);
} catch (InvalidAlgorithmParameterException e) {
throw new RuntimeException(e);
}
}
@Override
protected void engineInit(int opmode, Key key, AlgorithmParameterSpec params,
SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException {
final byte[] iv;
if (params instanceof IvParameterSpec) {
IvParameterSpec ivParams = (IvParameterSpec) params;
iv = ivParams.getIV();
} else {
iv = null;
}
engineInitInternal(opmode, key, iv, random);
}
@Override
protected void engineInit(int opmode, Key key, AlgorithmParameters params, SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
final AlgorithmParameterSpec spec;
if (params != null) {
try {
spec = params.getParameterSpec(IvParameterSpec.class);
} catch (InvalidParameterSpecException e) {
throw new InvalidAlgorithmParameterException(e);
}
} else {
spec = null;
}
engineInit(opmode, key, spec, random);
}
private final int updateInternal(byte[] input, int inputOffset, int inputLen, byte[] output,
int outputOffset, int maximumLen) throws ShortBufferException {
final int intialOutputOffset = outputOffset;
final int bytesLeft = output.length - outputOffset;
if (bytesLeft < maximumLen) {
throw new ShortBufferException("output buffer too small during update: " + bytesLeft
+ " < " + maximumLen);
}
outputOffset += NativeCrypto.EVP_CipherUpdate(cipherCtx.getContext(), output, outputOffset,
input, inputOffset, inputLen);
calledUpdate = true;
return outputOffset - intialOutputOffset;
}
@Override
protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen) {
final int maximumLen = getOutputSize(inputLen);
/* See how large our output buffer would need to be. */
final byte[] output;
if (maximumLen > 0) {
output = new byte[maximumLen];
} else {
output = EmptyArray.BYTE;
}
final int bytesWritten;
try {
bytesWritten = updateInternal(input, inputOffset, inputLen, output, 0, maximumLen);
} catch (ShortBufferException e) {
/* This shouldn't happen. */
throw new RuntimeException("calculated buffer size was wrong: " + maximumLen);
}
if (output.length == bytesWritten) {
return output;
} else if (bytesWritten == 0) {
return EmptyArray.BYTE;
} else {
return Arrays.copyOfRange(output, 0, bytesWritten);
}
}
@Override
protected int engineUpdate(byte[] input, int inputOffset, int inputLen, byte[] output,
int outputOffset) throws ShortBufferException {
final int maximumLen = getOutputSize(inputLen);
return updateInternal(input, inputOffset, inputLen, output, outputOffset, maximumLen);
}
/**
* Reset this Cipher instance state to process a new chunk of data.
*/
private void reset() {
NativeCrypto.EVP_CipherInit_ex(cipherCtx.getContext(), 0, encodedKey, iv, encrypting);
calledUpdate = false;
}
private int doFinalInternal(byte[] input, int inputOffset, int inputLen, byte[] output,
int outputOffset, int maximumLen) throws IllegalBlockSizeException,
BadPaddingException, ShortBufferException {
/* Remember this so we can tell how many characters were written. */
final int initialOutputOffset = outputOffset;
if (inputLen > 0) {
final int updateBytesWritten = updateInternal(input, inputOffset, inputLen, output,
outputOffset, maximumLen);
outputOffset += updateBytesWritten;
maximumLen -= updateBytesWritten;
}
/*
* If we're decrypting and haven't had any input, we should return null.
* Otherwise OpenSSL will complain if we call final.
*/
if (!encrypting && !calledUpdate) {
return 0;
}
/* Allow OpenSSL to pad if necessary and clean up state. */
final int bytesLeft = output.length - outputOffset;
final int writtenBytes;
if (bytesLeft >= maximumLen) {
writtenBytes = NativeCrypto.EVP_CipherFinal_ex(cipherCtx.getContext(), output,
outputOffset);
} else {
final byte[] lastBlock = new byte[maximumLen];
writtenBytes = NativeCrypto.EVP_CipherFinal_ex(cipherCtx.getContext(), lastBlock, 0);
if (writtenBytes > bytesLeft) {
throw new ShortBufferException("buffer is too short: " + writtenBytes + " > "
+ bytesLeft);
} else if (writtenBytes > 0) {
System.arraycopy(lastBlock, 0, output, outputOffset, writtenBytes);
}
}
outputOffset += writtenBytes;
reset();
return outputOffset - initialOutputOffset;
}
@Override
protected byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen)
throws IllegalBlockSizeException, BadPaddingException {
/*
* Other implementations return null if we've never called update()
* while decrypting.
*/
if (!encrypting && !calledUpdate && inputLen == 0) {
reset();
return null;
}
final int maximumLen = getOutputSize(inputLen);
/* Assume that we'll output exactly on a byte boundary. */
final byte[] output = new byte[maximumLen];
final int bytesWritten;
try {
bytesWritten = doFinalInternal(input, inputOffset, inputLen, output, 0, maximumLen);
} catch (ShortBufferException e) {
/* This should not happen since we sized our own buffer. */
throw new RuntimeException("our calculated buffer was too small", e);
}
if (bytesWritten == output.length) {
return output;
} else if (bytesWritten == 0) {
return EmptyArray.BYTE;
} else {
return Arrays.copyOfRange(output, 0, bytesWritten);
}
}
@Override
protected int engineDoFinal(byte[] input, int inputOffset, int inputLen, byte[] output,
int outputOffset) throws ShortBufferException, IllegalBlockSizeException,
BadPaddingException {
if (output == null) {
throw new NullPointerException("output == null");
}
final int maximumLen = getOutputSize(inputLen);
return doFinalInternal(input, inputOffset, inputLen, output, outputOffset, maximumLen);
}
@Override
protected byte[] engineWrap(Key key) throws IllegalBlockSizeException, InvalidKeyException {
try {
byte[] encoded = key.getEncoded();
return engineDoFinal(encoded, 0, encoded.length);
} catch (BadPaddingException e) {
IllegalBlockSizeException newE = new IllegalBlockSizeException();
newE.initCause(e);
throw newE;
}
}
@Override
protected Key engineUnwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, int wrappedKeyType)
throws InvalidKeyException, NoSuchAlgorithmException {
try {
byte[] encoded = engineDoFinal(wrappedKey, 0, wrappedKey.length);
if (wrappedKeyType == Cipher.PUBLIC_KEY) {
KeyFactory keyFactory = KeyFactory.getInstance(wrappedKeyAlgorithm);
return keyFactory.generatePublic(new X509EncodedKeySpec(encoded));
} else if (wrappedKeyType == Cipher.PRIVATE_KEY) {
KeyFactory keyFactory = KeyFactory.getInstance(wrappedKeyAlgorithm);
return keyFactory.generatePrivate(new PKCS8EncodedKeySpec(encoded));
} else if (wrappedKeyType == Cipher.SECRET_KEY) {
return new SecretKeySpec(encoded, wrappedKeyAlgorithm);
} else {
throw new UnsupportedOperationException("wrappedKeyType == " + wrappedKeyType);
}
} catch (IllegalBlockSizeException e) {
throw new InvalidKeyException(e);
} catch (BadPaddingException e) {
throw new InvalidKeyException(e);
} catch (InvalidKeySpecException e) {
throw new InvalidKeyException(e);
}
}
public static class AES extends OpenSSLCipher {
private static final int AES_BLOCK_SIZE = 16;
protected AES(Mode mode, Padding padding) {
super(mode, padding);
}
public static class CBC extends AES {
public CBC(Padding padding) {
super(Mode.CBC, padding);
}
public static class NoPadding extends CBC {
public NoPadding() {
super(Padding.NOPADDING);
}
}
public static class PKCS5Padding extends CBC {
public PKCS5Padding() {
super(Padding.PKCS5PADDING);
}
}
}
public static class CFB extends AES {
public CFB() {
super(Mode.CFB, Padding.NOPADDING);
}
}
public static class CTR extends AES {
public CTR() {
super(Mode.CTR, Padding.NOPADDING);
}
}
public static class ECB extends AES {
public ECB(Padding padding) {
super(Mode.ECB, padding);
}
public static class NoPadding extends ECB {
public NoPadding() {
super(Padding.NOPADDING);
}
}
public static class PKCS5Padding extends ECB {
public PKCS5Padding() {
super(Padding.PKCS5PADDING);
}
}
}
public static class OFB extends AES {
public OFB() {
super(Mode.OFB, Padding.NOPADDING);
}
}
@Override
protected void checkSupportedKeySize(int keyLength) throws InvalidKeyException {
switch (keyLength) {
case 16: // AES 128
case 24: // AES 192
case 32: // AES 256
return;
default:
throw new InvalidKeyException("Unsupported key size: " + keyLength + " bytes");
}
}
@Override
protected void checkSupportedMode(Mode mode) throws NoSuchAlgorithmException {
switch (mode) {
case CBC:
case CFB:
case CFB1:
case CFB8:
case CFB128:
case CTR:
case ECB:
case OFB:
return;
default:
throw new NoSuchAlgorithmException("Unsupported mode " + mode.toString());
}
}
@Override
protected void checkSupportedPadding(Padding padding) throws NoSuchPaddingException {
switch (padding) {
case NOPADDING:
case PKCS5PADDING:
return;
default:
throw new NoSuchPaddingException("Unsupported padding " + padding.toString());
}
}
@Override
protected String getBaseCipherName() {
return "AES";
}
@Override
protected String getCipherName(int keyLength, Mode mode) {
return "aes-" + (keyLength * 8) + "-" + mode.toString().toLowerCase(Locale.US);
}
@Override
protected int getCipherBlockSize() {
return AES_BLOCK_SIZE;
}
}
public static class DESEDE extends OpenSSLCipher {
private static int DES_BLOCK_SIZE = 8;
public DESEDE(Mode mode, Padding padding) {
super(mode, padding);
}
public static class CBC extends DESEDE {
public CBC(Padding padding) {
super(Mode.CBC, padding);
}
public static class NoPadding extends CBC {
public NoPadding() {
super(Padding.NOPADDING);
}
}
public static class PKCS5Padding extends CBC {
public PKCS5Padding() {
super(Padding.PKCS5PADDING);
}
}
}
public static class CFB extends DESEDE {
public CFB() {
super(Mode.CFB, Padding.NOPADDING);
}
}
public static class ECB extends DESEDE {
public ECB(Padding padding) {
super(Mode.ECB, padding);
}
public static class NoPadding extends ECB {
public NoPadding() {
super(Padding.NOPADDING);
}
}
public static class PKCS5Padding extends ECB {
public PKCS5Padding() {
super(Padding.PKCS5PADDING);
}
}
}
public static class OFB extends DESEDE {
public OFB() {
super(Mode.OFB, Padding.NOPADDING);
}
}
@Override
protected String getBaseCipherName() {
return "DESede";
}
@Override
protected String getCipherName(int keySize, Mode mode) {
final String baseCipherName;
if (keySize == 16) {
baseCipherName = "des-ede";
} else {
baseCipherName = "des-ede3";
}
if (mode == Mode.ECB) {
return baseCipherName;
} else {
return baseCipherName + "-" + mode.toString().toLowerCase(Locale.US);
}
}
@Override
protected void checkSupportedKeySize(int keySize) throws InvalidKeyException {
if (keySize != 16 && keySize != 24) {
throw new InvalidKeyException("key size must be 128 or 192 bits");
}
}
@Override
protected void checkSupportedMode(Mode mode) throws NoSuchAlgorithmException {
switch (mode) {
case CBC:
case CFB:
case CFB1:
case CFB8:
case ECB:
case OFB:
return;
default:
throw new NoSuchAlgorithmException("Unsupported mode " + mode.toString());
}
}
@Override
protected void checkSupportedPadding(Padding padding) throws NoSuchPaddingException {
switch (padding) {
case NOPADDING:
case PKCS5PADDING:
return;
default:
throw new NoSuchPaddingException("Unsupported padding " + padding.toString());
}
}
@Override
protected int getCipherBlockSize() {
return DES_BLOCK_SIZE;
}
}
public static class ARC4 extends OpenSSLCipher {
public ARC4() {
}
@Override
protected String getBaseCipherName() {
return "ARCFOUR";
}
@Override
protected String getCipherName(int keySize, Mode mode) {
return "rc4";
}
@Override
protected void checkSupportedKeySize(int keySize) throws InvalidKeyException {
}
@Override
protected void checkSupportedMode(Mode mode) throws NoSuchAlgorithmException {
throw new NoSuchAlgorithmException("ARC4 does not support modes");
}
@Override
protected void checkSupportedPadding(Padding padding) throws NoSuchPaddingException {
throw new NoSuchPaddingException("ARC4 does not support padding");
}
@Override
protected int getCipherBlockSize() {
return 0;
}
@Override
protected boolean supportsVariableSizeKey() {
return true;
}
}
}