private static PrivateKey derivePrivateKeyPBES2(
org.bouncycastle.asn1.pkcs.EncryptedPrivateKeyInfo eIn,
AlgorithmIdentifier algId,
char[] password)
throws GeneralSecurityException, InvalidCipherTextException {
PBES2Parameters pbeParams = new PBES2Parameters((ASN1Sequence) algId.getParameters());
CipherParameters cipherParams = extractPBES2CipherParams(password, pbeParams);
EncryptionScheme scheme = pbeParams.getEncryptionScheme();
BufferedBlockCipher cipher;
if (scheme.getAlgorithm().equals(PKCSObjectIdentifiers.RC2_CBC)) {
RC2CBCParameter rc2Params = new RC2CBCParameter((ASN1Sequence) scheme.getObject());
byte[] iv = rc2Params.getIV();
CipherParameters param = new ParametersWithIV(cipherParams, iv);
cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new RC2Engine()));
cipher.init(false, param);
} else {
byte[] iv = ((ASN1OctetString) scheme.getObject()).getOctets();
CipherParameters param = new ParametersWithIV(cipherParams, iv);
cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new DESedeEngine()));
cipher.init(false, param);
}
byte[] data = eIn.getEncryptedData();
byte[] out = new byte[cipher.getOutputSize(data.length)];
int len = cipher.processBytes(data, 0, data.length, out, 0);
len += cipher.doFinal(out, len);
byte[] pkcs8 = new byte[len];
System.arraycopy(out, 0, pkcs8, 0, len);
KeyFactory fact = KeyFactory.getInstance("RSA"); // It seems to work for both RSA and DSA.
return fact.generatePrivate(new PKCS8EncodedKeySpec(pkcs8));
}
private PasswordBasedCipherFactory getPBES2CipherFactory(EncryptionScheme scheme) {
try {
if (scheme.getAlgorithm().equals(PKCSObjectIdentifiers.encryptionAlgorithm.branch("9"))) {
RC5CBCParameter rc5Param = RC5CBCParameter.getInstance(scheme.getParameters());
if (rc5Param.getBlockSizeInBits().intValue() > 64) {
// RC5-CBC-Pad with a 128bits block size
return this.manager.getInstance(PasswordBasedCipherFactory.class, "PBES2-RC5-64-CBC-Pad");
}
}
return this.manager.getInstance(
PasswordBasedCipherFactory.class, scheme.getAlgorithm().getId());
} catch (ComponentLookupException e) {
throw new UnsupportedOperationException("Password based cipher factory not found.", e);
}
}
public PBES2Parameters(ASN1Sequence obj) {
Enumeration e = obj.getObjects();
ASN1Sequence funcSeq =
ASN1Sequence.getInstance(((DEREncodable) e.nextElement()).getDERObject());
if (funcSeq.getObjectAt(0).equals(id_PBKDF2)) {
func = new KeyDerivationFunc(id_PBKDF2, PBKDF2Params.getInstance(funcSeq.getObjectAt(1)));
} else {
func = new KeyDerivationFunc(funcSeq);
}
scheme = (EncryptionScheme) EncryptionScheme.getInstance(e.nextElement());
}
