org.bouncycastle.tls.crypto.impl.jcajce.RSAUtil Maven / Gradle / Ivy

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The Bouncy Castle Java APIs for the TLS, including a JSSE provider. The APIs are designed primarily to be used in conjunction with the BC FIPS provider. The APIs may also be used with other providers although if being used in a FIPS context it is the responsibility of the user to ensure that any other providers used are FIPS certified and used appropriately.

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package org.bouncycastle.tls.crypto.impl.jcajce;

import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.PSSParameterSpec;

import org.bouncycastle.jcajce.util.JcaJceHelper;
import org.bouncycastle.tls.crypto.TlsCryptoUtils;

class RSAUtil
{
    static String getDigestSigAlgName(
        String name)
    {
        int dIndex = name.indexOf('-');
        if (dIndex > 0 && !name.startsWith("SHA3"))
        {
            return name.substring(0, dIndex) + name.substring(dIndex + 1);
        }

        return name;
    }

    static AlgorithmParameterSpec getPSSParameterSpec(int cryptoHashAlgorithm, String digestName, JcaJceHelper helper)
    {
        int saltLength = TlsCryptoUtils.getHashOutputSize(cryptoHashAlgorithm);

        // Used where providers can't handle PSSParameterSpec properly.
//        AlgorithmIdentifier hashAlg = getHashAlgorithmID(cryptoHashAlgorithm);
//
//        RSASSAPSSparams pssParams = new RSASSAPSSparams(
//            hashAlg,
//            new AlgorithmIdentifier(PKCSObjectIdentifiers.id_mgf1, hashAlg),
//            new ASN1Integer(saltLength),
//            RSASSAPSSparams.DEFAULT_TRAILER_FIELD);
//
//        try
//        {
//            AlgorithmParameters params = helper.createAlgorithmParameters("PSS");
//
//            params.init(pssParams.getEncoded(), "ASN.1");
//
//            return params.getParameterSpec(AlgorithmParameterSpec.class);
//        }
//        catch (IOException e)
//        {   // this should never happen!
//            throw new IllegalStateException("cannot encode RSASSAPSSparams: " + e.getMessage());
//        }
//        catch (GeneralSecurityException e)
//        {
//            throw new IllegalStateException("cannot recover PSS paramSpec: " + e.getMessage());
//        }

        MGF1ParameterSpec mgf1Spec = new MGF1ParameterSpec(digestName);
        return new PSSParameterSpec(digestName, "MGF1", mgf1Spec, saltLength, 1);
    }

//    private static AlgorithmIdentifier getHashAlgorithmID(int cryptoHashAlgorithm)
//    {
//        switch (cryptoHashAlgorithm)
//        {
//        case CryptoHashAlgorithm.sha256:
//            return new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha256, DERNull.INSTANCE);
//        case CryptoHashAlgorithm.sha384:
//            return new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha384, DERNull.INSTANCE);
//        case CryptoHashAlgorithm.sha512:
//            return new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha512, DERNull.INSTANCE);
//        default:
//            return null;
//        }
//    }
}