package org.bouncycastle.crypto.test;

import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.util.encoders.Hex;
import org.bouncycastle.util.test.SimpleTestResult;
import org.bouncycastle.util.test.Test;
import org.bouncycastle.util.test.TestResult;

/**
 * SHA256 HMac Test
 */
public class SHA256HMacTest
    implements Test
{
    final static String[] keys = {
        "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
        "4a656665",
        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
        "0102030405060708090a0b0c0d0e0f10111213141516171819",
        "0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c",
        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
    };

    final static String[] digests = {
        "b0344c61d8db38535ca8afceaf0bf12b881dc200c9833da726e9376c2e32cff7",
        "5bdcc146bf60754e6a042426089575c75a003f089d2739839dec58b964ec3843",
        "773ea91e36800e46854db8ebd09181a72959098b3ef8c122d9635514ced565fe",
        "82558a389a443c0ea4cc819899f2083a85f0faa3e578f8077a2e3ff46729665b",
        "a3b6167473100ee06e0c796c2955552bfa6f7c0a6a8aef8b93f860aab0cd20c5",
        "60e431591ee0b67f0d8a26aacbf5b77f8e0bc6213728c5140546040f0ee37f54",
        "9b09ffa71b942fcb27635fbcd5b0e944bfdc63644f0713938a7f51535c3a35e2"
    };

    final static String[] messages = {
        "Hi There",
        "what do ya want for nothing?",
        "0xdddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd",
        "0xcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd",
        "Test With Truncation",
        "Test Using Larger Than Block-Size Key - Hash Key First",
        "This is a test using a larger than block-size key and a larger than block-size data. The key needs to be hashed before being used by the HMAC algorithm."
    };

    public static boolean arraysEqual(byte[] a, byte[] b)
    {
        if (a == b) return true;
        if (a.length != b.length) return false;

        for (int i = 0; i < a.length; i++)
        {
            if (a[i] != b[i]) return false;
        }

        return true;
    }
        
    public String getName()
    {
        return "SHA256HMac";
    }

    public TestResult perform()
    {
        HMac hmac = new HMac(new SHA256Digest());
        byte[] resBuf = new byte[hmac.getMacSize()];

        for (int i = 0; i < messages.length; i++)
        {
            byte[] m = messages[i].getBytes();
            if (messages[i].startsWith("0x"))
            {
                m = Hex.decode(messages[i].substring(2));
            }
            hmac.init(new KeyParameter(Hex.decode(keys[i])));
            hmac.update(m, 0, m.length);
            hmac.doFinal(resBuf, 0);

            if (!arraysEqual(resBuf, Hex.decode(digests[i])))
            {
                return new SimpleTestResult(false, getName() + ": Vector " + i + " failed got -" + new String(Hex.encode(resBuf)));
            }
        }

        //
        // test reset
        //
        int vector = 0; // vector used for test
        byte[] m = messages[vector].getBytes();
        if (messages[vector].startsWith("0x"))
        {
            m = Hex.decode(messages[vector].substring(2));
        }
        hmac.init(new KeyParameter(Hex.decode(keys[vector])));
        hmac.update(m, 0, m.length);
        hmac.doFinal(resBuf, 0);
        hmac.reset();
        hmac.update(m, 0, m.length);
        hmac.doFinal(resBuf, 0);

        if (!arraysEqual(resBuf, Hex.decode(digests[vector])))
        {
            return new SimpleTestResult(false, getName() +
                    "Reset with vector " + vector + " failed");
        }

        return new SimpleTestResult(true, getName() + ": Okay");
    }

    public static void main(
        String[]    args)
    {
        SHA256HMacTest    test = new SHA256HMacTest();
        TestResult      result = test.perform();

        System.out.println(result);
    }
}
