117 lines
3.9 KiB
Java
117 lines
3.9 KiB
Java
/**
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* Copyright (c) 2016 Vincent Breitmoser
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*
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* Licensed under the Bouncy Castle License (MIT license). See LICENSE file for details.
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*/
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package org.bouncycastle.openpgp.operator.jcajce;
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import java.security.InvalidAlgorithmParameterException;
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import java.security.InvalidKeyException;
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import java.security.Provider;
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import javax.crypto.BadPaddingException;
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import javax.crypto.Cipher;
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import javax.crypto.IllegalBlockSizeException;
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import javax.crypto.spec.IvParameterSpec;
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import org.bouncycastle.bcpg.S2K;
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import org.bouncycastle.jcajce.util.DefaultJcaJceHelper;
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import org.bouncycastle.jcajce.util.NamedJcaJceHelper;
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import org.bouncycastle.jcajce.util.ProviderJcaJceHelper;
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import org.bouncycastle.openpgp.PGPException;
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import org.bouncycastle.openpgp.operator.PBESecretKeyDecryptor;
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import org.bouncycastle.openpgp.operator.PGPDigestCalculatorProvider;
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/** This is a builder for a special PBESecretKeyDecryptor which is parametrized by a
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* fixed session key, which is used in place of the one obtained from a passphrase.
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*/
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public class SessionKeySecretKeyDecryptorBuilder
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{
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private OperatorHelper helper = new OperatorHelper(new DefaultJcaJceHelper());
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private PGPDigestCalculatorProvider calculatorProvider;
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private JcaPGPDigestCalculatorProviderBuilder calculatorProviderBuilder;
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public SessionKeySecretKeyDecryptorBuilder()
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{
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this.calculatorProviderBuilder = new JcaPGPDigestCalculatorProviderBuilder();
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}
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public SessionKeySecretKeyDecryptorBuilder(PGPDigestCalculatorProvider calculatorProvider)
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{
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this.calculatorProvider = calculatorProvider;
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}
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public SessionKeySecretKeyDecryptorBuilder setProvider(Provider provider)
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{
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this.helper = new OperatorHelper(new ProviderJcaJceHelper(provider));
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if (calculatorProviderBuilder != null)
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{
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calculatorProviderBuilder.setProvider(provider);
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}
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return this;
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}
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public SessionKeySecretKeyDecryptorBuilder setProvider(String providerName)
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{
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this.helper = new OperatorHelper(new NamedJcaJceHelper(providerName));
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if (calculatorProviderBuilder != null)
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{
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calculatorProviderBuilder.setProvider(providerName);
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}
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return this;
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}
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public PBESecretKeyDecryptor build(final byte[] sessionKey)
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throws PGPException
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{
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if (calculatorProvider == null)
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{
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calculatorProvider = calculatorProviderBuilder.build();
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}
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return new PBESecretKeyDecryptor(null, calculatorProvider)
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{
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@Override
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public byte[] makeKeyFromPassPhrase(int keyAlgorithm, S2K s2k) throws PGPException {
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return sessionKey;
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}
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public byte[] recoverKeyData(int encAlgorithm, byte[] key, byte[] iv, byte[] keyData, int keyOff, int keyLen)
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throws PGPException
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{
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try
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{
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Cipher c = helper.createCipher(PGPUtil.getSymmetricCipherName(encAlgorithm) + "/CFB/NoPadding");
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c.init(Cipher.DECRYPT_MODE, PGPUtil.makeSymmetricKey(encAlgorithm, key), new IvParameterSpec(iv));
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return c.doFinal(keyData, keyOff, keyLen);
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}
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catch (IllegalBlockSizeException e)
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{
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throw new PGPException("illegal block size: " + e.getMessage(), e);
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}
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catch (BadPaddingException e)
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{
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throw new PGPException("bad padding: " + e.getMessage(), e);
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}
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catch (InvalidAlgorithmParameterException e)
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{
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throw new PGPException("invalid parameter: " + e.getMessage(), e);
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}
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catch (InvalidKeyException e)
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{
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throw new PGPException("invalid key: " + e.getMessage(), e);
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}
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}
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};
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}
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}
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