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 static CipherParameters extractPBES2CipherParams(
char[] password, PBES2Parameters pbeParams) {
PBKDF2Params pbkdfParams =
PBKDF2Params.getInstance(pbeParams.getKeyDerivationFunc().getParameters());
int keySize = 192;
if (pbkdfParams.getKeyLength() != null) {
keySize = pbkdfParams.getKeyLength().intValue() * 8;
}
int iterationCount = pbkdfParams.getIterationCount().intValue();
byte[] salt = pbkdfParams.getSalt();
PBEParametersGenerator generator = new PKCS5S2ParametersGenerator();
generator.init(PBEParametersGenerator.PKCS5PasswordToBytes(password), salt, iterationCount);
return generator.generateDerivedParameters(keySize);
}
public OutputEncryptor build() throws OperatorCreationException {
final AlgorithmIdentifier algID;
salt = new byte[20];
if (random == null) {
random = new SecureRandom();
}
random.nextBytes(salt);
try {
this.cipher = helper.createCipher(algOID.getId());
if (PEMUtilities.isPKCS5Scheme2(algOID)) {
this.paramGen = helper.createAlgorithmParameterGenerator(algOID.getId());
} else {
this.secKeyFact = helper.createSecretKeyFactory(algOID.getId());
}
} catch (GeneralSecurityException e) {
throw new OperatorCreationException(algOID + " not available: " + e.getMessage(), e);
}
if (PEMUtilities.isPKCS5Scheme2(algOID)) {
params = paramGen.generateParameters();
try {
KeyDerivationFunc scheme =
new KeyDerivationFunc(algOID, ASN1Primitive.fromByteArray(params.getEncoded()));
KeyDerivationFunc func =
new KeyDerivationFunc(
PKCSObjectIdentifiers.id_PBKDF2, new PBKDF2Params(salt, iterationCount));
ASN1EncodableVector v = new ASN1EncodableVector();
v.add(func);
v.add(scheme);
algID =
new AlgorithmIdentifier(
PKCSObjectIdentifiers.id_PBES2, PBES2Parameters.getInstance(new DERSequence(v)));
} catch (IOException e) {
throw new OperatorCreationException(e.getMessage(), e);
}
key =
PEMUtilities.generateSecretKeyForPKCS5Scheme2(
algOID.getId(), password, salt, iterationCount);
try {
cipher.init(Cipher.ENCRYPT_MODE, key, params);
} catch (GeneralSecurityException e) {
throw new OperatorCreationException(e.getMessage(), e);
}
} else if (PEMUtilities.isPKCS12(algOID)) {
ASN1EncodableVector v = new ASN1EncodableVector();
v.add(new DEROctetString(salt));
v.add(new ASN1Integer(iterationCount));
algID = new AlgorithmIdentifier(algOID, PKCS12PBEParams.getInstance(new DERSequence(v)));
try {
PBEKeySpec pbeSpec = new PBEKeySpec(password);
PBEParameterSpec defParams = new PBEParameterSpec(salt, iterationCount);
key = secKeyFact.generateSecret(pbeSpec);
cipher.init(Cipher.ENCRYPT_MODE, key, defParams);
} catch (GeneralSecurityException e) {
throw new OperatorCreationException(e.getMessage(), e);
}
} else {
throw new OperatorCreationException("unknown algorithm: " + algOID, null);
}
return new OutputEncryptor() {
public AlgorithmIdentifier getAlgorithmIdentifier() {
return algID;
}
public OutputStream getOutputStream(OutputStream encOut) {
return new CipherOutputStream(encOut, cipher);
}
public GenericKey getKey() {
return new JceGenericKey(algID, key);
}
};
}
