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package org.spongycastle.openpgp.operator.bc;
import java.io.InputStream;
import org.spongycastle.crypto.BlockCipher;
import org.spongycastle.crypto.BufferedBlockCipher;
import org.spongycastle.crypto.io.CipherInputStream;
import org.spongycastle.crypto.modes.CFBBlockCipher;
import org.spongycastle.crypto.modes.OpenPGPCFBBlockCipher;
import org.spongycastle.crypto.params.KeyParameter;
import org.spongycastle.crypto.params.ParametersWithIV;
import org.spongycastle.openpgp.operator.PGPDataDecryptor;
import org.spongycastle.openpgp.operator.PGPDigestCalculator;
class BcUtil
{
static BufferedBlockCipher createStreamCipher(boolean forEncryption, BlockCipher engine, boolean withIntegrityPacket, byte[] key)
{
BufferedBlockCipher c;
if (withIntegrityPacket)
{
c = new BufferedBlockCipher(new CFBBlockCipher(engine, engine.getBlockSize() * 8));
}
else
{
c = new BufferedBlockCipher(new OpenPGPCFBBlockCipher(engine));
}
KeyParameter keyParameter = new KeyParameter(key);
if (withIntegrityPacket)
{
c.init(forEncryption, new ParametersWithIV(keyParameter, new byte[engine.getBlockSize()]));
}
else
{
c.init(forEncryption, keyParameter);
}
return c;
}
public static PGPDataDecryptor createDataDecryptor(boolean withIntegrityPacket, BlockCipher engine, byte[] key)
{
final BufferedBlockCipher c = createStreamCipher(false, engine, withIntegrityPacket, key);
return new PGPDataDecryptor()
{
public InputStream getInputStream(InputStream in)
{
return new CipherInputStream(in, c);
}
public int getBlockSize()
{
return c.getBlockSize();
}
public PGPDigestCalculator getIntegrityCalculator()
{
return new SHA1PGPDigestCalculator();
}
};
}
public static BufferedBlockCipher createSymmetricKeyWrapper(boolean forEncryption, BlockCipher engine, byte[] key, byte[] iv)
{
BufferedBlockCipher c = new BufferedBlockCipher(new CFBBlockCipher(engine, engine.getBlockSize() * 8));
c.init(forEncryption, new ParametersWithIV(new KeyParameter(key), iv));
return c;
}
}
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