package org.bouncycastle.jcajce.provider.digest;

import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

import javax.crypto.SecretKey;
import javax.crypto.spec.PBEKeySpec;

import org.bouncycastle.asn1.iana.IANAObjectIdentifiers;
import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.crypto.CipherKeyGenerator;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.jcajce.provider.config.ConfigurableProvider;
import org.bouncycastle.jcajce.provider.symmetric.util.BCPBEKey;
import org.bouncycastle.jcajce.provider.symmetric.util.BaseKeyGenerator;
import org.bouncycastle.jcajce.provider.symmetric.util.BaseMac;
import org.bouncycastle.jcajce.provider.symmetric.util.BaseSecretKeyFactory;
import org.bouncycastle.jcajce.provider.symmetric.util.PBE;
import org.bouncycastle.jcajce.provider.symmetric.util.PBESecretKeyFactory;

public class SHA1
{
    private SHA1()
    {

    }

    static public class Digest
        extends BCMessageDigest
        implements Cloneable
    {
        public Digest()
        {
            super(new SHA1Digest());
        }

        public Object clone()
            throws CloneNotSupportedException
        {
            Digest d = (Digest)super.clone();
            d.digest = new SHA1Digest((SHA1Digest)digest);

            return d;
        }
    }

    /**
     * SHA1 HMac
     */
    public static class HashMac
        extends BaseMac
    {
        public HashMac()
        {
            super(new HMac(new SHA1Digest()));
        }
    }

    public static class KeyGenerator
        extends BaseKeyGenerator
    {
        public KeyGenerator()
        {
            super("HMACSHA1", 160, new CipherKeyGenerator());
        }
    }

    /**
     * SHA1 HMac
     */
    public static class SHA1Mac
        extends BaseMac
    {
        public SHA1Mac()
        {
            super(new HMac(new SHA1Digest()));
        }
    }

    /**
     * PBEWithHmacSHA
     */
    public static class PBEWithMacKeyFactory
        extends PBESecretKeyFactory
    {
        public PBEWithMacKeyFactory()
        {
            super("PBEwithHmacSHA", null, false, PKCS12, SHA1, 160, 0);
        }
    }


    public static class BasePBKDF2WithHmacSHA1
        extends BaseSecretKeyFactory
    {
        private int scheme;

        public BasePBKDF2WithHmacSHA1(String name, int scheme)
        {
            super(name, PKCSObjectIdentifiers.id_PBKDF2);

            this.scheme = scheme;
        }

        protected SecretKey engineGenerateSecret(
            KeySpec keySpec)
            throws InvalidKeySpecException
        {
            if (keySpec instanceof PBEKeySpec)
            {
                PBEKeySpec pbeSpec = (PBEKeySpec)keySpec;

                if (pbeSpec.getSalt() == null)
                {
                    throw new InvalidKeySpecException("missing required salt");
                }

                if (pbeSpec.getIterationCount() <= 0)
                {
                    throw new InvalidKeySpecException("positive iteration count required: "
                        + pbeSpec.getIterationCount());
                }

                if (pbeSpec.getKeyLength() <= 0)
                {
                    throw new InvalidKeySpecException("positive key length required: "
                        + pbeSpec.getKeyLength());
                }

                if (pbeSpec.getPassword().length == 0)
                {
                    throw new IllegalArgumentException("password empty");
                }

                int digest = SHA1;
                int keySize = pbeSpec.getKeyLength();
                int ivSize = -1;    // JDK 1,2 and earlier does not understand simplified version.
                CipherParameters param = PBE.Util.makePBEMacParameters(pbeSpec, scheme, digest, keySize);

                return new BCPBEKey(this.algName, this.algOid, scheme, digest, keySize, ivSize, pbeSpec, param);
            }

            throw new InvalidKeySpecException("Invalid KeySpec");
        }
    }

    public static class PBKDF2WithHmacSHA1UTF8
        extends BasePBKDF2WithHmacSHA1
    {
        public PBKDF2WithHmacSHA1UTF8()
        {
            super("PBKDF2WithHmacSHA1", PKCS5S2_UTF8);
        }
    }

    public static class PBKDF2WithHmacSHA18BIT
        extends BasePBKDF2WithHmacSHA1
    {
        public PBKDF2WithHmacSHA18BIT()
        {
            super("PBKDF2WithHmacSHA1And8bit", PKCS5S2);
        }
    }

    public static class Mappings
        extends DigestAlgorithmProvider
    {
        private static final String PREFIX = SHA1.class.getName();

        public Mappings()
        {
        }

        public void configure(ConfigurableProvider provider)
        {
            provider.addAlgorithm("MessageDigest.SHA-1", PREFIX + "$Digest");
            provider.addAlgorithm("Alg.Alias.MessageDigest.SHA1", "SHA-1");
            provider.addAlgorithm("Alg.Alias.MessageDigest.SHA", "SHA-1");
            provider.addAlgorithm("Alg.Alias.MessageDigest." + OIWObjectIdentifiers.idSHA1, "SHA-1");

            addHMACAlgorithm(provider, "SHA1", PREFIX + "$HashMac", PREFIX + "$KeyGenerator");
            addHMACAlias(provider, "SHA1", PKCSObjectIdentifiers.id_hmacWithSHA1);
            addHMACAlias(provider, "SHA1", IANAObjectIdentifiers.hmacSHA1);

            provider.addAlgorithm("Mac.PBEWITHHMACSHA", PREFIX + "$SHA1Mac");
            provider.addAlgorithm("Mac.PBEWITHHMACSHA1", PREFIX + "$SHA1Mac");
            provider.addAlgorithm("Alg.Alias.SecretKeyFactory.PBEWITHHMACSHA", "PBEWITHHMACSHA1");
            provider.addAlgorithm("Alg.Alias.SecretKeyFactory." + OIWObjectIdentifiers.idSHA1, "PBEWITHHMACSHA1");
            provider.addAlgorithm("Alg.Alias.Mac." + OIWObjectIdentifiers.idSHA1, "PBEWITHHMACSHA");

            provider.addAlgorithm("SecretKeyFactory.PBEWITHHMACSHA1", PREFIX + "$PBEWithMacKeyFactory");
            provider.addAlgorithm("SecretKeyFactory.PBKDF2WithHmacSHA1", PREFIX + "$PBKDF2WithHmacSHA1UTF8");
            provider.addAlgorithm("Alg.Alias.SecretKeyFactory." + PKCSObjectIdentifiers.id_PBKDF2, "PBKDF2WithHmacSHA1");
            provider.addAlgorithm("Alg.Alias.SecretKeyFactory.PBKDF2WithHmacSHA1AndUTF8", "PBKDF2WithHmacSHA1");
            provider.addAlgorithm("SecretKeyFactory.PBKDF2WithHmacSHA1And8BIT", PREFIX + "$PBKDF2WithHmacSHA18BIT");
        }
    }
}