public PublicKey getPublicKey(PGPPublicKey publicKey) throws PGPException {
KeyFactory fact;
PublicKeyPacket publicPk = publicKey.getPublicKeyPacket();
try {
switch (publicPk.getAlgorithm()) {
case PublicKeyAlgorithmTags.RSA_ENCRYPT:
case PublicKeyAlgorithmTags.RSA_GENERAL:
case PublicKeyAlgorithmTags.RSA_SIGN:
RSAPublicBCPGKey rsaK = (RSAPublicBCPGKey) publicPk.getKey();
RSAPublicKeySpec rsaSpec =
new RSAPublicKeySpec(rsaK.getModulus(), rsaK.getPublicExponent());
fact = helper.createKeyFactory("RSA");
return fact.generatePublic(rsaSpec);
case PublicKeyAlgorithmTags.DSA:
DSAPublicBCPGKey dsaK = (DSAPublicBCPGKey) publicPk.getKey();
DSAPublicKeySpec dsaSpec =
new DSAPublicKeySpec(dsaK.getY(), dsaK.getP(), dsaK.getQ(), dsaK.getG());
fact = helper.createKeyFactory("DSA");
return fact.generatePublic(dsaSpec);
case PublicKeyAlgorithmTags.ELGAMAL_ENCRYPT:
case PublicKeyAlgorithmTags.ELGAMAL_GENERAL:
ElGamalPublicBCPGKey elK = (ElGamalPublicBCPGKey) publicPk.getKey();
ElGamalPublicKeySpec elSpec =
new ElGamalPublicKeySpec(
elK.getY(), new ElGamalParameterSpec(elK.getP(), elK.getG()));
fact = helper.createKeyFactory("ElGamal");
return fact.generatePublic(elSpec);
default:
throw new PGPException("unknown public key algorithm encountered");
}
} catch (PGPException e) {
throw e;
} catch (Exception e) {
throw new PGPException("exception constructing public key", e);
}
}
public byte[] calculateFingerprint(PublicKeyPacket publicPk) throws PGPException {
BCPGKey key = publicPk.getKey();
Digest digest;
if (publicPk.getVersion() <= 3) {
RSAPublicBCPGKey rK = (RSAPublicBCPGKey) key;
try {
digest = new MD5Digest();
byte[] bytes = new MPInteger(rK.getModulus()).getEncoded();
digest.update(bytes, 2, bytes.length - 2);
bytes = new MPInteger(rK.getPublicExponent()).getEncoded();
digest.update(bytes, 2, bytes.length - 2);
} catch (IOException e) {
throw new PGPException("can't encode key components: " + e.getMessage(), e);
}
} else {
try {
byte[] kBytes = publicPk.getEncodedContents();
digest = new SHA1Digest();
digest.update((byte) 0x99);
digest.update((byte) (kBytes.length >> 8));
digest.update((byte) kBytes.length);
digest.update(kBytes, 0, kBytes.length);
} catch (IOException e) {
throw new PGPException("can't encode key components: " + e.getMessage(), e);
}
}
byte[] digBuf = new byte[digest.getDigestSize()];
digest.doFinal(digBuf, 0);
return digBuf;
}