package org.bouncycastle.jcajce.util;

import java.util.HashMap;
import java.util.Map;

import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.cryptopro.CryptoProObjectIdentifiers;
import org.bouncycastle.asn1.gm.GMObjectIdentifiers;
import org.bouncycastle.asn1.nist.NISTObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.teletrust.TeleTrusTObjectIdentifiers;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.internal.asn1.gnu.GNUObjectIdentifiers;
import org.bouncycastle.internal.asn1.iso.ISOIECObjectIdentifiers;
import org.bouncycastle.internal.asn1.misc.MiscObjectIdentifiers;
import org.bouncycastle.internal.asn1.oiw.OIWObjectIdentifiers;

public class MessageDigestUtils
{
    private static Map<ASN1ObjectIdentifier, String> digestOidMap = new HashMap<ASN1ObjectIdentifier, String>();
    private static Map<String, AlgorithmIdentifier> digestAlgIdMap = new HashMap<String, AlgorithmIdentifier>();

    static
    {
        digestOidMap.put(PKCSObjectIdentifiers.md2, "MD2");
        digestOidMap.put(PKCSObjectIdentifiers.md4, "MD4");
        digestOidMap.put(PKCSObjectIdentifiers.md5, "MD5");
        digestOidMap.put(OIWObjectIdentifiers.idSHA1, "SHA-1");
        digestOidMap.put(NISTObjectIdentifiers.id_sha224, "SHA-224");
        digestOidMap.put(NISTObjectIdentifiers.id_sha256, "SHA-256");
        digestOidMap.put(NISTObjectIdentifiers.id_sha384, "SHA-384");
        digestOidMap.put(NISTObjectIdentifiers.id_sha512, "SHA-512");
        digestOidMap.put(NISTObjectIdentifiers.id_sha512_224, "SHA-512(224)");
        digestOidMap.put(NISTObjectIdentifiers.id_sha512_256, "SHA-512(256)");
        digestOidMap.put(TeleTrusTObjectIdentifiers.ripemd128, "RIPEMD-128");
        digestOidMap.put(TeleTrusTObjectIdentifiers.ripemd160, "RIPEMD-160");
        digestOidMap.put(TeleTrusTObjectIdentifiers.ripemd256, "RIPEMD-128");
        digestOidMap.put(ISOIECObjectIdentifiers.ripemd128, "RIPEMD-128");
        digestOidMap.put(ISOIECObjectIdentifiers.ripemd160, "RIPEMD-160");
        digestOidMap.put(CryptoProObjectIdentifiers.gostR3411, "GOST3411");
        digestOidMap.put(GNUObjectIdentifiers.Tiger_192, "Tiger");
        digestOidMap.put(ISOIECObjectIdentifiers.whirlpool, "Whirlpool");
        digestOidMap.put(NISTObjectIdentifiers.id_sha3_224, "SHA3-224");
        digestOidMap.put(NISTObjectIdentifiers.id_sha3_256, "SHA3-256");
        digestOidMap.put(NISTObjectIdentifiers.id_sha3_384, "SHA3-384");
        digestOidMap.put(NISTObjectIdentifiers.id_sha3_512, "SHA3-512");
        digestOidMap.put(NISTObjectIdentifiers.id_shake128, "SHAKE128");
        digestOidMap.put(NISTObjectIdentifiers.id_shake256, "SHAKE256");
        digestOidMap.put(GMObjectIdentifiers.sm3, "SM3");
        digestOidMap.put(MiscObjectIdentifiers.blake3_256, "BLAKE3-256");

        digestAlgIdMap.put("SHA-1", new AlgorithmIdentifier(OIWObjectIdentifiers.idSHA1, DERNull.INSTANCE));
        digestAlgIdMap.put("SHA-224", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha224));
        digestAlgIdMap.put("SHA224", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha224));
        digestAlgIdMap.put("SHA-256", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha256));
        digestAlgIdMap.put("SHA256", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha256));
        digestAlgIdMap.put("SHA-384", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha384));
        digestAlgIdMap.put("SHA384", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha384));
        digestAlgIdMap.put("SHA-512", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha512));
        digestAlgIdMap.put("SHA512", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha512));
        digestAlgIdMap.put("SHA3-224", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha3_224));
        digestAlgIdMap.put("SHA3-256", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha3_256));
        digestAlgIdMap.put("SHA3-384", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha3_384));
        digestAlgIdMap.put("SHA3-512", new AlgorithmIdentifier(NISTObjectIdentifiers.id_sha3_512));
        digestAlgIdMap.put("BLAKE3-256", new AlgorithmIdentifier(MiscObjectIdentifiers.blake3_256));
    }

    /**
     * Attempt to find a standard JCA name for the digest represented by the passed in OID.
     *
     * @param digestName name of the digest algorithm of interest.
     * @return an algorithm identifier representing the digest.
     */
    public static AlgorithmIdentifier getDigestAlgID(String digestName)
    {
        if (digestAlgIdMap.containsKey(digestName))
        {
            return (AlgorithmIdentifier)digestAlgIdMap.get(digestName);
        }
        throw new IllegalArgumentException("unknown digest: " + digestName);
    }

    /**
     * Attempt to find a standard JCA name for the digest represented by the passed in OID.
     *
     * @param digestAlgOID the OID of the digest algorithm of interest.
     * @return a string representing the standard name - the OID as a string if none available.
     */
    public static String getDigestName(ASN1ObjectIdentifier digestAlgOID)
    {
        String name = (String)digestOidMap.get(digestAlgOID);  // for pre 1.5 JDK
        if (name != null)
        {
            return name;
        }

        return digestAlgOID.getId();
    }
}
