Examples with AlgorithmIdentifier org.mozilla.jss.pkix.primitive.AlgorithmIdentifier used on opensource projects

Example 11 with AlgorithmIdentifier

use of org.mozilla.jss.pkix.primitive.AlgorithmIdentifier in project jss by dogtagpki.

the class EncryptedContentInfo method decrypt.

/**
 * Decrypts the content of an EncryptedContentInfo encrypted with a
 * PBE key.
 *
 * @param pass The password to use in generating the PBE decryption key.
 * @param charToByteConverter The converter for converting the password
 *      characters into bytes.  May be null to use the default.
 * @return The decrypted contents of the EncryptedContentInfo. The contents
 *      are first unpadded using the PKCS padding mechanism.
 */
public byte[] decrypt(Password pass, KeyGenerator.CharToByteConverter charToByteConverter) throws IllegalStateException, NotInitializedException, NoSuchAlgorithmException, InvalidBERException, IOException, InvalidKeyException, InvalidAlgorithmParameterException, TokenException, IllegalBlockSizeException, BadPaddingException {
    if (encryptedContent == null) {
        return null;
    }
    // get the key gen parameters
    AlgorithmIdentifier algid = contentEncryptionAlgorithm;
    KeyGenAlgorithm kgAlg = KeyGenAlgorithm.fromOID(algid.getOID());
    if (!(kgAlg instanceof PBEAlgorithm)) {
        throw new NoSuchAlgorithmException("KeyGenAlgorithm is not a" + " PBE algorithm");
    }
    ASN1Value params = algid.getParameters();
    if (params == null) {
        throw new InvalidAlgorithmParameterException("PBE algorithms require parameters");
    }
    PBEParameter pbeParams;
    if (params instanceof PBEParameter) {
        pbeParams = (PBEParameter) params;
    } else {
        byte[] encodedParams = ASN1Util.encode(params);
        pbeParams = (PBEParameter) ASN1Util.decode(PBEParameter.getTemplate(), encodedParams);
    }
    PBEKeyGenParams kgp = new PBEKeyGenParams(pass, pbeParams.getSalt(), pbeParams.getIterations());
    // compute the key and IV
    CryptoToken token = CryptoManager.getInstance().getInternalCryptoToken();
    KeyGenerator kg = token.getKeyGenerator(kgAlg);
    if (charToByteConverter != null) {
        kg.setCharToByteConverter(charToByteConverter);
    }
    kg.initialize(kgp);
    SymmetricKey key = kg.generate();
    // compute algorithm parameters
    EncryptionAlgorithm encAlg = ((PBEAlgorithm) kgAlg).getEncryptionAlg();
    AlgorithmParameterSpec algParams = null;
    Class<?>[] paramClasses = encAlg.getParameterClasses();
    for (int i = 0; i < paramClasses.length; i++) {
        if (paramClasses[i].equals(javax.crypto.spec.IvParameterSpec.class)) {
            algParams = new IVParameterSpec(kg.generatePBE_IV());
            break;
        }
    }
    // perform the decryption
    Cipher cipher = token.getCipherContext(encAlg);
    cipher.initDecrypt(key, algParams);
    return Cipher.unPad(cipher.doFinal(encryptedContent.toByteArray()));
}