org.bouncycastle.jcajce.provider.asymmetric.elgamal.CipherSpi Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcprov-jdk18on Show documentation
Show all versions of bcprov-jdk18on Show documentation
The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.8 and up.
package org.bouncycastle.jcajce.provider.asymmetric.elgamal;
import java.security.AlgorithmParameters;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.InvalidParameterException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.MGF1ParameterSpec;
import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.ShortBufferException;
import javax.crypto.interfaces.DHKey;
import javax.crypto.interfaces.DHPrivateKey;
import javax.crypto.interfaces.DHPublicKey;
import javax.crypto.spec.OAEPParameterSpec;
import javax.crypto.spec.PSource;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.crypto.AsymmetricBlockCipher;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.encodings.ISO9796d1Encoding;
import org.bouncycastle.crypto.encodings.OAEPEncoding;
import org.bouncycastle.crypto.encodings.PKCS1Encoding;
import org.bouncycastle.crypto.engines.ElGamalEngine;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.jcajce.provider.asymmetric.util.BaseCipherSpi;
import org.bouncycastle.jcajce.provider.util.BadBlockException;
import org.bouncycastle.jcajce.provider.util.DigestFactory;
import org.bouncycastle.jce.interfaces.ElGamalKey;
import org.bouncycastle.util.Strings;
public class CipherSpi
extends BaseCipherSpi
{
private AsymmetricBlockCipher cipher;
private AlgorithmParameterSpec paramSpec;
private AlgorithmParameters engineParams;
private ErasableOutputStream bOut = new ErasableOutputStream();
public CipherSpi(
AsymmetricBlockCipher engine)
{
cipher = engine;
}
private void initFromSpec(
OAEPParameterSpec pSpec)
throws NoSuchPaddingException
{
MGF1ParameterSpec mgfParams = (MGF1ParameterSpec)pSpec.getMGFParameters();
Digest digest = DigestFactory.getDigest(mgfParams.getDigestAlgorithm());
if (digest == null)
{
throw new NoSuchPaddingException("no match on OAEP constructor for digest algorithm: "+ mgfParams.getDigestAlgorithm());
}
cipher = new OAEPEncoding(new ElGamalEngine(), digest, ((PSource.PSpecified)pSpec.getPSource()).getValue());
paramSpec = pSpec;
}
protected int engineGetBlockSize()
{
return cipher.getInputBlockSize();
}
protected int engineGetKeySize(
Key key)
{
if (key instanceof ElGamalKey)
{
ElGamalKey k = (ElGamalKey)key;
return k.getParameters().getP().bitLength();
}
else if (key instanceof DHKey)
{
DHKey k = (DHKey)key;
return k.getParams().getP().bitLength();
}
throw new IllegalArgumentException("not an ElGamal key!");
}
protected int engineGetOutputSize(
int inputLen)
{
return cipher.getOutputBlockSize();
}
protected AlgorithmParameters engineGetParameters()
{
if (engineParams == null)
{
if (paramSpec != null)
{
try
{
engineParams = createParametersInstance("OAEP");
engineParams.init(paramSpec);
}
catch (Exception e)
{
throw new RuntimeException(e.toString());
}
}
}
return engineParams;
}
protected void engineSetMode(
String mode)
throws NoSuchAlgorithmException
{
String md = Strings.toUpperCase(mode);
if (md.equals("NONE") || md.equals("ECB"))
{
return;
}
throw new NoSuchAlgorithmException("can't support mode " + mode);
}
protected void engineSetPadding(
String padding)
throws NoSuchPaddingException
{
String pad = Strings.toUpperCase(padding);
if (pad.equals("NOPADDING"))
{
cipher = new ElGamalEngine();
}
else if (pad.equals("PKCS1PADDING"))
{
cipher = new PKCS1Encoding(new ElGamalEngine());
}
else if (pad.equals("ISO9796-1PADDING"))
{
cipher = new ISO9796d1Encoding(new ElGamalEngine());
}
else if (pad.equals("OAEPPADDING"))
{
initFromSpec(OAEPParameterSpec.DEFAULT);
}
else if (pad.equals("OAEPWITHMD5ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("MD5", "MGF1", new MGF1ParameterSpec("MD5"), PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA1ANDMGF1PADDING"))
{
initFromSpec(OAEPParameterSpec.DEFAULT);
}
else if (pad.equals("OAEPWITHSHA224ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA-224", "MGF1", new MGF1ParameterSpec("SHA-224"), PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA256ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256, PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA384ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA-384", "MGF1", MGF1ParameterSpec.SHA384, PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA512ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA-512", "MGF1", MGF1ParameterSpec.SHA512, PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA3-224ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA3-224", "MGF1", new MGF1ParameterSpec("SHA3-224"), PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA3-256ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA3-256", "MGF1", new MGF1ParameterSpec("SHA3-256"), PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA3-384ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA3-384", "MGF1", new MGF1ParameterSpec("SHA3-384"), PSource.PSpecified.DEFAULT));
}
else if (pad.equals("OAEPWITHSHA3-512ANDMGF1PADDING"))
{
initFromSpec(new OAEPParameterSpec("SHA3-512", "MGF1", new MGF1ParameterSpec("SHA3-512"), PSource.PSpecified.DEFAULT));
}
else
{
throw new NoSuchPaddingException(padding + " unavailable with ElGamal.");
}
}
protected void engineInit(
int opmode,
Key key,
AlgorithmParameterSpec params,
SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException
{
CipherParameters param;
if (key instanceof DHPublicKey)
{
param = ElGamalUtil.generatePublicKeyParameter((PublicKey)key);
}
else if (key instanceof DHPrivateKey)
{
param = ElGamalUtil.generatePrivateKeyParameter((PrivateKey)key);
}
else
{
throw new InvalidKeyException("unknown key type passed to ElGamal");
}
if (params instanceof OAEPParameterSpec)
{
OAEPParameterSpec spec = (OAEPParameterSpec)params;
paramSpec = params;
if (!spec.getMGFAlgorithm().equalsIgnoreCase("MGF1") && !spec.getMGFAlgorithm().equals(PKCSObjectIdentifiers.id_mgf1.getId()))
{
throw new InvalidAlgorithmParameterException("unknown mask generation function specified");
}
if (!(spec.getMGFParameters() instanceof MGF1ParameterSpec))
{
throw new InvalidAlgorithmParameterException("unkown MGF parameters");
}
Digest digest = DigestFactory.getDigest(spec.getDigestAlgorithm());
if (digest == null)
{
throw new InvalidAlgorithmParameterException("no match on digest algorithm: "+ spec.getDigestAlgorithm());
}
MGF1ParameterSpec mgfParams = (MGF1ParameterSpec)spec.getMGFParameters();
Digest mgfDigest = DigestFactory.getDigest(mgfParams.getDigestAlgorithm());
if (mgfDigest == null)
{
throw new InvalidAlgorithmParameterException("no match on MGF digest algorithm: "+ mgfParams.getDigestAlgorithm());
}
cipher = new OAEPEncoding(new ElGamalEngine(), digest, mgfDigest, ((PSource.PSpecified)spec.getPSource()).getValue());
}
else if (params != null)
{
throw new InvalidAlgorithmParameterException("unknown parameter type.");
}
if (random != null)
{
param = new ParametersWithRandom(param, random);
}
switch (opmode)
{
case javax.crypto.Cipher.ENCRYPT_MODE:
case javax.crypto.Cipher.WRAP_MODE:
cipher.init(true, param);
break;
case javax.crypto.Cipher.DECRYPT_MODE:
case javax.crypto.Cipher.UNWRAP_MODE:
cipher.init(false, param);
break;
default:
throw new InvalidParameterException("unknown opmode " + opmode + " passed to ElGamal");
}
}
protected void engineInit(
int opmode,
Key key,
AlgorithmParameters params,
SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException
{
throw new InvalidAlgorithmParameterException("can't handle parameters in ElGamal");
}
protected void engineInit(
int opmode,
Key key,
SecureRandom random)
throws InvalidKeyException
{
try
{
engineInit(opmode, key, (AlgorithmParameterSpec)null, random);
}
catch (InvalidAlgorithmParameterException e)
{
// this shouldn't happen
throw new InvalidKeyException("Eeeek! " + e.toString(), e);
}
}
protected byte[] engineUpdate(
byte[] input,
int inputOffset,
int inputLen)
{
bOut.write(input, inputOffset, inputLen);
return null;
}
protected int engineUpdate(
byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
{
bOut.write(input, inputOffset, inputLen);
return 0;
}
protected byte[] engineDoFinal(
byte[] input,
int inputOffset,
int inputLen)
throws IllegalBlockSizeException, BadPaddingException
{
if (input != null)
{
bOut.write(input, inputOffset, inputLen);
}
if (cipher instanceof ElGamalEngine)
{
if (bOut.size() > cipher.getInputBlockSize() + 1)
{
throw new ArrayIndexOutOfBoundsException("too much data for ElGamal block");
}
}
else
{
if (bOut.size() > cipher.getInputBlockSize())
{
throw new ArrayIndexOutOfBoundsException("too much data for ElGamal block");
}
}
return getOutput();
}
protected int engineDoFinal(
byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
throws IllegalBlockSizeException, BadPaddingException, ShortBufferException
{
if (outputOffset + engineGetOutputSize(inputLen) > output.length)
{
throw new ShortBufferException("output buffer too short for input.");
}
if (input != null)
{
bOut.write(input, inputOffset, inputLen);
}
if (cipher instanceof ElGamalEngine)
{
if (bOut.size() > cipher.getInputBlockSize() + 1)
{
throw new ArrayIndexOutOfBoundsException("too much data for ElGamal block");
}
}
else
{
if (bOut.size() > cipher.getInputBlockSize())
{
throw new ArrayIndexOutOfBoundsException("too much data for ElGamal block");
}
}
byte[] out = getOutput();
for (int i = 0; i != out.length; i++)
{
output[outputOffset + i] = out[i];
}
return out.length;
}
private byte[] getOutput()
throws BadPaddingException
{
try
{
return cipher.processBlock(bOut.getBuf(), 0, bOut.size());
}
catch (InvalidCipherTextException e)
{
throw new BadBlockException("unable to decrypt block", e);
}
catch (ArrayIndexOutOfBoundsException e)
{
throw new BadBlockException("unable to decrypt block", e);
}
finally
{
bOut.erase();
}
}
/**
* classes that inherit from us.
*/
static public class NoPadding
extends CipherSpi
{
public NoPadding()
{
super(new ElGamalEngine());
}
}
static public class PKCS1v1_5Padding
extends CipherSpi
{
public PKCS1v1_5Padding()
{
super(new PKCS1Encoding(new ElGamalEngine()));
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy