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The Bouncy Castle Java API for handling the OpenPGP protocol. This jar contains the OpenPGP API for JDK 1.5 to JDK 1.7. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
package org.bouncycastle.openpgp.operator;
import java.io.IOException;
import java.io.OutputStream;
import org.bouncycastle.bcpg.HashAlgorithmTags;
import org.bouncycastle.bcpg.S2K;
import org.bouncycastle.bcpg.SymmetricKeyAlgorithmTags;
import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.util.Strings;
/**
* Basic utility class
*/
class PGPUtil
implements HashAlgorithmTags
{
static byte[] makeKeyFromPassPhrase(
PGPDigestCalculator digestCalculator,
int algorithm,
S2K s2k,
char[] passPhrase)
throws PGPException
{
// TODO: Never used
String algName = null;
int keySize = 0;
switch (algorithm)
{
case SymmetricKeyAlgorithmTags.TRIPLE_DES:
keySize = 192;
algName = "DES_EDE";
break;
case SymmetricKeyAlgorithmTags.IDEA:
keySize = 128;
algName = "IDEA";
break;
case SymmetricKeyAlgorithmTags.CAST5:
keySize = 128;
algName = "CAST5";
break;
case SymmetricKeyAlgorithmTags.BLOWFISH:
keySize = 128;
algName = "Blowfish";
break;
case SymmetricKeyAlgorithmTags.SAFER:
keySize = 128;
algName = "SAFER";
break;
case SymmetricKeyAlgorithmTags.DES:
keySize = 64;
algName = "DES";
break;
case SymmetricKeyAlgorithmTags.AES_128:
keySize = 128;
algName = "AES";
break;
case SymmetricKeyAlgorithmTags.AES_192:
keySize = 192;
algName = "AES";
break;
case SymmetricKeyAlgorithmTags.AES_256:
keySize = 256;
algName = "AES";
break;
case SymmetricKeyAlgorithmTags.TWOFISH:
keySize = 256;
algName = "Twofish";
break;
case SymmetricKeyAlgorithmTags.CAMELLIA_128:
keySize = 128;
algName = "Camellia";
break;
case SymmetricKeyAlgorithmTags.CAMELLIA_192:
keySize = 192;
algName = "Camellia";
break;
case SymmetricKeyAlgorithmTags.CAMELLIA_256:
keySize = 256;
algName = "Camellia";
break;
default:
throw new PGPException("unknown symmetric algorithm: " + algorithm);
}
byte[] pBytes = Strings.toUTF8ByteArray(passPhrase);
byte[] keyBytes = new byte[(keySize + 7) / 8];
int generatedBytes = 0;
int loopCount = 0;
if (s2k != null)
{
if (s2k.getHashAlgorithm() != digestCalculator.getAlgorithm())
{
throw new PGPException("s2k/digestCalculator mismatch");
}
}
else
{
if (digestCalculator.getAlgorithm() != HashAlgorithmTags.MD5)
{
throw new PGPException("digestCalculator not for MD5");
}
}
OutputStream dOut = digestCalculator.getOutputStream();
try
{
while (generatedBytes < keyBytes.length)
{
if (s2k != null)
{
for (int i = 0; i != loopCount; i++)
{
dOut.write(0);
}
byte[] iv = s2k.getIV();
switch (s2k.getType())
{
case S2K.SIMPLE:
dOut.write(pBytes);
break;
case S2K.SALTED:
dOut.write(iv);
dOut.write(pBytes);
break;
case S2K.SALTED_AND_ITERATED:
long count = s2k.getIterationCount();
dOut.write(iv);
dOut.write(pBytes);
count -= iv.length + pBytes.length;
while (count > 0)
{
if (count < iv.length)
{
dOut.write(iv, 0, (int)count);
break;
}
else
{
dOut.write(iv);
count -= iv.length;
}
if (count < pBytes.length)
{
dOut.write(pBytes, 0, (int)count);
count = 0;
}
else
{
dOut.write(pBytes);
count -= pBytes.length;
}
}
break;
default:
throw new PGPException("unknown S2K type: " + s2k.getType());
}
}
else
{
for (int i = 0; i != loopCount; i++)
{
dOut.write((byte)0);
}
dOut.write(pBytes);
}
dOut.close();
byte[] dig = digestCalculator.getDigest();
if (dig.length > (keyBytes.length - generatedBytes))
{
System.arraycopy(dig, 0, keyBytes, generatedBytes, keyBytes.length - generatedBytes);
}
else
{
System.arraycopy(dig, 0, keyBytes, generatedBytes, dig.length);
}
generatedBytes += dig.length;
loopCount++;
}
}
catch (IOException e)
{
throw new PGPException("exception calculating digest: " + e.getMessage(), e);
}
for (int i = 0; i != pBytes.length; i++)
{
pBytes[i] = 0;
}
return keyBytes;
}
public static byte[] makeKeyFromPassPhrase(
PGPDigestCalculatorProvider digCalcProvider,
int algorithm,
S2K s2k,
char[] passPhrase)
throws PGPException
{
PGPDigestCalculator digestCalculator;
if (s2k != null)
{
digestCalculator = digCalcProvider.get(s2k.getHashAlgorithm());
}
else
{
digestCalculator = digCalcProvider.get(HashAlgorithmTags.MD5);
}
return makeKeyFromPassPhrase(digestCalculator, algorithm, s2k, passPhrase);
}
}