/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package javax.xml.crypto.test.dsig;

import java.lang.reflect.Constructor;
import java.nio.charset.StandardCharsets;
import java.security.Key;
import java.security.Provider;
import java.security.Security;
import java.util.Collections;

import javax.xml.crypto.KeySelector;
import javax.xml.crypto.dom.DOMStructure;
import javax.xml.crypto.dsig.CanonicalizationMethod;
import javax.xml.crypto.dsig.DigestMethod;
import javax.xml.crypto.dsig.Reference;
import javax.xml.crypto.dsig.SignatureMethod;
import javax.xml.crypto.dsig.SignedInfo;
import javax.xml.crypto.dsig.XMLObject;
import javax.xml.crypto.dsig.XMLSignature;
import javax.xml.crypto.dsig.XMLSignatureFactory;
import javax.xml.crypto.dsig.dom.DOMSignContext;
import javax.xml.crypto.dsig.dom.DOMValidateContext;
import javax.xml.crypto.dsig.keyinfo.KeyInfo;
import javax.xml.crypto.dsig.spec.C14NMethodParameterSpec;
import javax.xml.crypto.dsig.spec.HMACParameterSpec;
import javax.xml.crypto.test.KeySelectors;

import org.junit.jupiter.api.Assumptions;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;


/**
 * Test signing using all available HMAC signing algorithms
 */
public class HMACSignatureAlgorithmTest {

    private static boolean bcInstalled;
    private KeySelector sks;
    private CanonicalizationMethod withoutComments;
    private DigestMethod sha1;
    private SignatureMethod hmacSha1, hmacSha224, hmacSha256, hmacSha384, hmacSha512, ripemd160, hmacSha256ParamSpec;
    private XMLSignatureFactory fac;

    static {
        Security.insertProviderAt
            (new org.apache.jcp.xml.dsig.internal.dom.XMLDSigRI(), 1);
    }

    @org.junit.jupiter.api.BeforeAll
    public static void setup() throws Exception {
        //
        // If the BouncyCastle provider is not installed, then try to load it
        // via reflection.
        //
        if (Security.getProvider("BC") == null) {
            Constructor<?> cons = null;
            try {
                Class<?> c = Class.forName("org.bouncycastle.jce.provider.BouncyCastleProvider");
                cons = c.getConstructor(new Class[] {});
            } catch (Exception e) {
                //ignore
            }
            if (cons != null) {
                Provider provider = (Provider)cons.newInstance();
                Security.insertProviderAt(provider, 2);
                bcInstalled = true;
            }
        }
    }

    public HMACSignatureAlgorithmTest() throws Exception {

        // create common objects
        fac = XMLSignatureFactory.getInstance("DOM", new org.apache.jcp.xml.dsig.internal.dom.XMLDSigRI());
        withoutComments = fac.newCanonicalizationMethod
            (CanonicalizationMethod.INCLUSIVE, (C14NMethodParameterSpec) null);

        // Digest Methods
        sha1 = fac.newDigestMethod(DigestMethod.SHA1, null);

        hmacSha1 = fac.newSignatureMethod("http://www.w3.org/2000/09/xmldsig#hmac-sha1", null);
        hmacSha224 = fac.newSignatureMethod("http://www.w3.org/2001/04/xmldsig-more#hmac-sha224", null);
        hmacSha256 = fac.newSignatureMethod("http://www.w3.org/2001/04/xmldsig-more#hmac-sha256", null);
        hmacSha256ParamSpec  = fac.newSignatureMethod("http://www.w3.org/2001/04/xmldsig-more#hmac-sha256",
                                                      new HMACParameterSpec(256));
        hmacSha384 = fac.newSignatureMethod("http://www.w3.org/2001/04/xmldsig-more#hmac-sha384", null);
        hmacSha512 = fac.newSignatureMethod("http://www.w3.org/2001/04/xmldsig-more#hmac-sha512", null);
        ripemd160 = fac.newSignatureMethod("http://www.w3.org/2001/04/xmldsig-more#hmac-ripemd160", null);

        sks = new KeySelectors.SecretKeySelector("testkey".getBytes(StandardCharsets.US_ASCII));
    }

    @org.junit.jupiter.api.AfterAll
    public static void cleanup() throws Exception {
        Security.removeProvider("BC");
    }

    @org.junit.jupiter.api.Test
    public void testHMACSHA1() throws Exception {
        test_create_signature_enveloping(hmacSha1, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    @org.junit.jupiter.api.Test
    public void testHMACSHA_224() throws Exception {
        test_create_signature_enveloping(hmacSha224, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    @org.junit.jupiter.api.Test
    public void testHMACSHA_256() throws Exception {
        test_create_signature_enveloping(hmacSha256, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    @org.junit.jupiter.api.Test
    public void testHMACSHA_256_ParamSpec() throws Exception {
        test_create_signature_enveloping(hmacSha256ParamSpec, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    @org.junit.jupiter.api.Test
    public void testHMACSHA_384() throws Exception {
        test_create_signature_enveloping(hmacSha384, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    @org.junit.jupiter.api.Test
    public void testHMACSHA_512() throws Exception {
        test_create_signature_enveloping(hmacSha512, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    @org.junit.jupiter.api.Test
    public void testHMACRIPEMD160() throws Exception {
        Assumptions.assumeTrue(bcInstalled);
        test_create_signature_enveloping(ripemd160, sha1, null,
                                         TestUtils.getSecretKey("testkey".getBytes(StandardCharsets.US_ASCII)), sks);
    }

    private void test_create_signature_enveloping(
        SignatureMethod sm, DigestMethod dm, KeyInfo ki, Key signingKey, KeySelector ks
    ) throws Exception {

        // create reference
        Reference ref = fac.newReference("#DSig.Object_1", dm, null,
                                         XMLObject.TYPE, null);

        // create SignedInfo
        SignedInfo si = fac.newSignedInfo(withoutComments, sm,
                                          Collections.singletonList(ref));

        Document doc = TestUtils.newDocument();
        // create Objects
        Element webElem = doc.createElementNS(null, "Web");
        Text text = doc.createTextNode("up up and away");
        webElem.appendChild(text);
        XMLObject obj = fac.newXMLObject(Collections.singletonList
                                         (new DOMStructure(webElem)), "DSig.Object_1", "text/xml", null);

        // create XMLSignature
        XMLSignature sig = fac.newXMLSignature
        (si, ki, Collections.singletonList(obj), null, null);

        DOMSignContext dsc = new DOMSignContext(signingKey, doc);
        dsc.setDefaultNamespacePrefix("dsig");

        sig.sign(dsc);
        TestUtils.validateSecurityOrEncryptionElement(doc.getDocumentElement());

        // XMLUtils.outputDOM(doc.getDocumentElement(), System.out);

        DOMValidateContext dvc = new DOMValidateContext
        (ks, doc.getDocumentElement());
        XMLSignature sig2 = fac.unmarshalXMLSignature(dvc);

        assertEquals(sig, sig2);
        assertTrue(sig2.validate(dvc));
    }

}