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);
}
protected RecipientOperator getRecipientOperator(Recipient recipient)
throws CMSException, IOException {
PasswordRecipient pbeRecipient = (PasswordRecipient) recipient;
AlgorithmIdentifier kekAlg = AlgorithmIdentifier.getInstance(info.getKeyEncryptionAlgorithm());
ASN1Sequence kekAlgParams = (ASN1Sequence) kekAlg.getParameters();
DERObjectIdentifier kekAlgName = DERObjectIdentifier.getInstance(kekAlgParams.getObjectAt(0));
PBKDF2Params params =
PBKDF2Params.getInstance(info.getKeyDerivationAlgorithm().getParameters());
byte[] derivedKey;
int keySize = ((Integer) KEYSIZES.get(kekAlgName)).intValue();
if (pbeRecipient.getPasswordConversionScheme() == PasswordRecipient.PKCS5_SCHEME2) {
PKCS5S2ParametersGenerator gen = new PKCS5S2ParametersGenerator();
gen.init(
PBEParametersGenerator.PKCS5PasswordToBytes(pbeRecipient.getPassword()),
params.getSalt(),
params.getIterationCount().intValue());
derivedKey = ((KeyParameter) gen.generateDerivedParameters(keySize)).getKey();
} else {
PKCS5S2ParametersGenerator gen = new PKCS5S2ParametersGenerator();
gen.init(
PBEParametersGenerator.PKCS5PasswordToUTF8Bytes(pbeRecipient.getPassword()),
params.getSalt(),
params.getIterationCount().intValue());
derivedKey = ((KeyParameter) gen.generateDerivedParameters(keySize)).getKey();
}
return pbeRecipient.getRecipientOperator(
AlgorithmIdentifier.getInstance(kekAlg.getParameters()),
messageAlgorithm,
derivedKey,
info.getEncryptedKey().getOctets());
}