ECDSAAlgorithmTest.java

package com.auth0.jwt.algorithms;

import com.auth0.jwt.JWT;
import com.auth0.jwt.exceptions.SignatureGenerationException;
import com.auth0.jwt.exceptions.SignatureVerificationException;
import com.auth0.jwt.interfaces.ECDSAKeyProvider;
import com.auth0.jwt.interfaces.JWTVerifier;
import org.hamcrest.Matchers;
import org.hamcrest.collection.IsIn;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import java.io.ByteArrayOutputStream;
import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.interfaces.ECKey;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.ECParameterSpec;
import java.util.Arrays;
import java.util.Base64;

import static com.auth0.jwt.PemUtils.readPrivateKeyFromFile;
import static com.auth0.jwt.PemUtils.readPublicKeyFromFile;
import static com.auth0.jwt.algorithms.CryptoTestHelper.asJWT;
import static com.auth0.jwt.algorithms.CryptoTestHelper.assertSignaturePresent;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.Matchers.isA;
import static org.hamcrest.Matchers.nullValue;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.internal.matchers.ThrowableMessageMatcher.hasMessage;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

public class ECDSAAlgorithmTest {

    private static final String PRIVATE_KEY_FILE_256 = "src/test/resources/ec256-key-private.pem";
    private static final String PUBLIC_KEY_FILE_256 = "src/test/resources/ec256-key-public.pem";
    private static final String INVALID_PUBLIC_KEY_FILE_256 = "src/test/resources/ec256-key-public-invalid.pem";
    
    private static final String PRIVATE_KEY_FILE_384 = "src/test/resources/ec384-key-private.pem";
    private static final String PUBLIC_KEY_FILE_384 = "src/test/resources/ec384-key-public.pem";
    private static final String INVALID_PUBLIC_KEY_FILE_384 = "src/test/resources/ec384-key-public-invalid.pem";

    private static final String PRIVATE_KEY_FILE_512 = "src/test/resources/ec512-key-private.pem";
    private static final String PUBLIC_KEY_FILE_512 = "src/test/resources/ec512-key-public.pem";
    private static final String INVALID_PUBLIC_KEY_FILE_512 = "src/test/resources/ec512-key-public-invalid.pem";

    @Rule
    public ExpectedException exception = ExpectedException.none();

    //JOSE Signatures obtained using Node 'jwa' lib: https://github.com/brianloveswords/node-jwa
    //DER Signatures obtained from source JOSE signature using 'ecdsa-sig-formatter' lib: https://github.com/Brightspace/node-ecdsa-sig-formatter

    //These tests use the default preferred SecurityProvider to handle ECDSA algorithms

    // Verify

    @Test
    public void shouldPassECDSA256VerificationWithJOSESignature() throws Exception {
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.4iVk3-Y0v4RT4_9IaQlp-8dZ_4fsTzIylgrPTDLrEvTHBTyVS3tgPbr2_IZfLETtiKRqCg0aQ5sh9eIsTTwB1g";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        Algorithm algorithm = Algorithm.ECDSA256(key);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnECDSA256VerificationWithDERSignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.MEYCIQDiJWTf5jShFPj0hpCWn7x1nhxPMjKWCs9MMusS9AIhAMcFPJVLe2A9uvb8hl8sRO2IpGoKDRpDmyH14ixNPAHW";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        Algorithm algorithm = Algorithm.ECDSA256(key);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA256VerificationWithJOSESignatureWithBothKeys() throws Exception {
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.4iVk3-Y0v4RT4_9IaQlp-8dZ_4fsTzIylgrPTDLrEvTHBTyVS3tgPbr2_IZfLETtiKRqCg0aQ5sh9eIsTTwB1g";
        Algorithm algorithm = Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnECDSA256VerificationWithDERSignatureWithBothKeys() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.MEYCIQDiJWTf5jShFPj0hpCWn7x1nhxPMjKWCs9MMusS9AIhAMcFPJVLe2A9uvb8hl8sRO2IpGoKDRpDmyH14ixNPAHW";
        Algorithm algorithm = Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA256VerificationWithProvidedPublicKey() throws Exception {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        PublicKey publicKey = readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        when(provider.getPublicKeyById("my-key-id")).thenReturn((ECPublicKey) publicKey);
        String jwt = "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15LWtleS1pZCJ9.eyJpc3MiOiJhdXRoMCJ9.D_oU4CB0ZEsxHOjcWnmS3ZJvlTzm6WcGFx-HASxnvcB2Xu2WjI-axqXH9xKq45aPBDs330JpRhJmqBSc2K8MXQ";
        Algorithm algorithm = Algorithm.ECDSA256(provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA256VerificationWhenProvidedPublicKeyIsNull() {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Public Key is null.")));
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPublicKeyById("my-key-id")).thenReturn(null);
        String jwt = "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15LWtleS1pZCJ9.eyJpc3MiOiJhdXRoMCJ9.D_oU4CB0ZEsxHOjcWnmS3ZJvlTzm6WcGFx-HASxnvcB2Xu2WjI-axqXH9xKq45aPBDs330JpRhJmqBSc2K8MXQ";
        Algorithm algorithm = Algorithm.ECDSA256(provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA256VerificationWithInvalidPublicKey() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.W9qfN1b80B9hnMo49WL8THrOsf1vEjOhapeFemPMGySzxTcgfyudS5esgeBTO908X5SLdAr5jMwPUPBs9b6nNg";
        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA256VerificationWhenUsingPrivateKey() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Public Key is null.")));
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.W9qfN1b80B9hnMo49WL8THrOsf1vEjOhapeFemPMGySzxTcgfyudS5esgeBTO908X5SLdAr5jMwPUPBs9b6nNg";
        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA256VerificationOnInvalidJOSESignatureLength() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        byte[] bytes = new byte[63];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA256VerificationOnInvalidJOSESignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");

        byte[] bytes = new byte[64];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA256VerificationOnInvalidDERSignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");

        byte[] bytes = new byte[64];
        bytes[0] = 0x30;
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_256, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA384VerificationWithJOSESignature() throws Exception {
        String jwt = "eyJhbGciOiJFUzM4NCJ9.eyJpc3MiOiJhdXRoMCJ9.50UU5VKNdF1wfykY8jQBKpvuHZoe6IZBJm5NvoB8bR-hnRg6ti-CHbmvoRtlLfnHfwITa_8cJMy6TenMC2g63GQHytc8rYoXqbwtS4R0Ko_AXbLFUmfxnGnMC6v4MS_z";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC");
        Algorithm algorithm = Algorithm.ECDSA384(key);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnECDSA384VerificationWithDERSignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        String jwt = "eyJhbGciOiJFUzM4NCJ9.eyJpc3MiOiJhdXRoMCJ9.MGUCMQDnRRTlUo10XXBKRjyNAEqm4dmh7ohkEmbk2gHxtH6GdGDq2L4IduahG2UtccCMH8CE2vHCTMuk3pzAtoOtxkB8rXPK2KF6m8LUuEdCqPwF2yxVJn8ZxpzAurDEv8w";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC");
        Algorithm algorithm = Algorithm.ECDSA384(key);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA384VerificationWithJOSESignatureWithBothKeys() throws Exception {
        String jwt = "eyJhbGciOiJFUzM4NCJ9.eyJpc3MiOiJhdXRoMCJ9.50UU5VKNdF1wfykY8jQBKpvuHZoe6IZBJm5NvoB8bR-hnRg6ti-CHbmvoRtlLfnHfwITa_8cJMy6TenMC2g63GQHytc8rYoXqbwtS4R0Ko_AXbLFUmfxnGnMC6v4MS_z";
        Algorithm algorithm = Algorithm.ECDSA384((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnECDSA384VerificationWithDERSignatureWithBothKeys() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        String jwt = "eyJhbGciOiJFUzM4NCJ9.eyJpc3MiOiJhdXRoMCJ9.MGUCMQDnRRTlUo10XXBKRjyNAEqm4dmh7ohkEmbk2gHxtH6GdGDq2L4IduahG2UccCMH8CE2vHCTMuk3pzAtoOtxkB8rXPK2KF6m8LUuEdCqPwF2yxVJn8ZxpzAurDEv8w";
        Algorithm algorithm = Algorithm.ECDSA384((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA384VerificationWithProvidedPublicKey() throws Exception {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        PublicKey publicKey = readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC");
        when(provider.getPublicKeyById("my-key-id")).thenReturn((ECPublicKey) publicKey);
        String jwt = "eyJhbGciOiJFUzM4NCIsImtpZCI6Im15LWtleS1pZCJ9.eyJpc3MiOiJhdXRoMCJ9.9kjGuFTPx3ylfpqL0eY9H7TGmPepjQOBKI8UPoEvby6N7dDLF5HxLohosNxxFymNT7LzpeSgOPAB0wJEwG2Nl2ukgdUOpZOf492wog_i5ZcZmAykd3g1QH7onrzd69GU";
        Algorithm algorithm = Algorithm.ECDSA384(provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA384VerificationWhenProvidedPublicKeyIsNull() {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Public Key is null.")));
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPublicKeyById("my-key-id")).thenReturn(null);
        String jwt = "eyJhbGciOiJFUzM4NCIsImtpZCI6Im15LWtleS1pZCJ9.eyJpc3MiOiJhdXRoMCJ9.9kjGuFTPx3ylfpqL0eY9H7TGmPepjQOBKI8UPoEvby6N7dDLF5HxLohosNxxFymNT7LzpeSgOPAB0wJEwG2Nl2ukgdUOpZOf492wog_i5ZcZmAykd3g1QH7onrzd69GU";
        Algorithm algorithm = Algorithm.ECDSA384(provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA384VerificationWithInvalidPublicKey() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");
        String jwt = "eyJhbGciOiJFUzM4NCJ9.eyJpc3MiOiJhdXRoMCJ9._k5h1KyO-NE0R2_HAw0-XEc0bGT5atv29SxHhOGC9JDqUHeUdptfCK_ljQ01nLVt2OQWT2SwGs-TuyHDFmhPmPGFZ9wboxvq_ieopmYqhQilNAu-WF-frioiRz9733fU";
        Algorithm algorithm = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA384VerificationWhenUsingPrivateKey() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Public Key is null.")));
        String jwt = "eyJhbGciOiJFUzM4NCJ9.eyJpc3MiOiJhdXRoMCJ9._k5h1KyO-NE0R2_HAw0-XEc0bGT5atv29SxHhOGC9JDqUHeUdptfCK_ljQ01nLVt2OQWT2SwGs-TuyHDFmhPmPGFZ9wboxvq_ieopmYqhQilNAu-WF-frioiRz9733fU";
        Algorithm algorithm = Algorithm.ECDSA384((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA384VerificationOnInvalidJOSESignatureLength() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        byte[] bytes = new byte[95];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA384VerificationOnInvalidJOSESignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");

        byte[] bytes = new byte[96];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA384VerificationOnInvalidDERSignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA384withECDSA");

        byte[] bytes = new byte[96];
        new SecureRandom().nextBytes(bytes);
        bytes[0] = 0x30;
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_384, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA512VerificationWithJOSESignature() throws Exception {
        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.AeCJPDIsSHhwRSGZCY6rspi8zekOw0K9qYMNridP1Fu9uhrA1QrG-EUxXlE06yvmh2R7Rz0aE7kxBwrnq8L8aOBCAYAsqhzPeUvyp8fXjjgs0Eto5I0mndE2QHlgcMSFASyjHbU8wD2Rq7ZNzGQ5b2MZfpv030WGUajT-aZYWFUJHVg2";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        Algorithm algorithm = Algorithm.ECDSA512(key);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnECDSA512VerificationWithDERSignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.MIGIAkIB4Ik8MixIeHBFIZkJjquymLzN6Q7DQr2pgw2uJ0UW726GsDVCsb4RTFeUTTrKaHZHtHPRoTuTEHCuerwvxo4EICQgGALKocz3lL8qfH1444LNBLaOSNJp3RNkB5YHDEhQEsox21PMA9kau2TcxkOW9jGX6b9N9FhlGo0mmWFhVCR1YNg";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        Algorithm algorithm = Algorithm.ECDSA512(key);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA512VerificationWithJOSESignatureWithBothKeys() throws Exception {
        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.AeCJPDIsSHhwRSGZCY6rspi8zekOw0K9qYMNridP1Fu9uhrA1QrG-EUxXlE06yvmh2R7Rz0aE7kxBwrnq8L8aOBCAYAsqhzPeUvyp8fXjjgs0Eto5I0mndE2QHlgcMSFASyjHbU8wD2Rq7ZNzGQ5b2MZfpv030WGUajT-aZYWFUJHVg2";
        Algorithm algorithm = Algorithm.ECDSA512((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowECDSA512VerificationWithDERSignatureWithBothKeys() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.MIGIAkIB4Ik8MixIeHBFIZkJjquymLzN6Q7DQr2pgw2uJ0UW726GsDVCsb4RTFeUTTrKaHZHtHPRoTuTEHCuerwvxo4EICQgGALKocz3lL8qfH1444LNBLaOSNJp3RNkB5YHDEhQEsox21PMA9kau2TcxkOW9jGX6b9N9FhlGo0mmWFhVCR1YNg";
        Algorithm algorithm = Algorithm.ECDSA512((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldPassECDSA512VerificationWithProvidedPublicKey() throws Exception {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        PublicKey publicKey = readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        when(provider.getPublicKeyById("my-key-id")).thenReturn((ECPublicKey) publicKey);
        String jwt = "eyJhbGciOiJFUzUxMiIsImtpZCI6Im15LWtleS1pZCJ9.eyJpc3MiOiJhdXRoMCJ9.AGxEwbsYa2bQ7Y7DAcTQnVD8PmLSlhJ20jg2OfdyPnqdXI8SgBaG6lGciq3_pofFhs1HEoFoJ33Jcluha24oMHIvAfwu8qbv_Wq3L2eI9Q0L0p6ul8Pd_BS8adRa2PgLc36xXGcRc7ID5YH-CYaQfsTp5YIaF0Po3h0QyCoQ6ZiYQkqm";
        Algorithm algorithm = Algorithm.ECDSA512(provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA512VerificationWhenProvidedPublicKeyIsNull() {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Public Key is null.")));
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPublicKeyById("my-key-id")).thenReturn(null);
        String jwt = "eyJhbGciOiJFUzUxMiIsImtpZCI6Im15LWtleS1pZCJ9.eyJpc3MiOiJhdXRoMCJ9.AGxEwbsYa2bQ7Y7DAcTQnVD8PmLSlhJ20jg2OfdyPnqdXI8SgBaG6lGciq3_pofFhs1HEoFoJ33Jcluha24oMHIvAfwu8qbv_Wq3L2eI9Q0L0p6ul8Pd_BS8adRa2PgLc36xXGcRc7ID5YH-CYaQfsTp5YIaF0Po3h0QyCoQ6ZiYQkqm";
        Algorithm algorithm = Algorithm.ECDSA512(provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA512VerificationWithInvalidPublicKey() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");
        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.AZgdopFFsN0amCSs2kOucXdpylD31DEm5ChK1PG0_gq5Mf47MrvVph8zHSVuvcrXzcE1U3VxeCg89mYW1H33Y-8iAF0QFkdfTUQIWKNObH543WNMYYssv3OtOj0znPv8atDbaF8DMYAtcT1qdmaSJRhx-egRE9HGZkinPh9CfLLLt58X";
        Algorithm algorithm = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA512VerificationWhenUsingPrivateKey() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Public Key is null.")));
        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.AZgdopFFsN0amCSs2kOucXdpylD31DEm5ChK1PG0_gq5Mf47MrvVph8zHSVuvcrXzcE1U3VxeCg89mYW1H33Y-8iAF0QFkdfTUQIWKNObH543WNMYYssv3OtOj0znPv8atDbaF8DMYAtcT1qdmaSJRhx-egRE9HGZkinPh9CfLLLt58X";
        Algorithm algorithm = Algorithm.ECDSA512((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA512VerificationOnInvalidJOSESignatureLength() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        byte[] bytes = new byte[131];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA512VerificationOnInvalidJOSESignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");

        byte[] bytes = new byte[132];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailECDSA512VerificationOnInvalidDERSignature() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA512withECDSA");

        byte[] bytes = new byte[132];
        new SecureRandom().nextBytes(bytes);
        bytes[0] = 0x30;
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;
        Algorithm algorithm = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(INVALID_PUBLIC_KEY_FILE_512, "EC"));
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailJOSEToDERConversionOnInvalidJOSESignatureLength() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(SignatureException.class));
        exception.expectCause(hasMessage(is("Invalid JOSE signature format.")));

        byte[] bytes = new byte[256];
        new SecureRandom().nextBytes(bytes);
        String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9." + signature;

        ECPublicKey publicKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm("ES256", "SHA256withECDSA", 128, provider);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnVerifyWhenSignatureAlgorithmDoesNotExists() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: some-alg");
        exception.expectCause(isA(NoSuchAlgorithmException.class));

        CryptoHelper crypto = mock(CryptoHelper.class);
        when(crypto.verifySignatureFor(anyString(), any(PublicKey.class), any(String.class), any(String.class), any(byte[].class)))
                .thenThrow(NoSuchAlgorithmException.class);

        ECPublicKey publicKey = mock(ECPublicKey.class);
        when(publicKey.getParams()).thenReturn(mock(ECParameterSpec.class));
        byte[] a = new byte[64];
        Arrays.fill(a, Byte.MAX_VALUE);
        when(publicKey.getParams().getOrder()).thenReturn(new BigInteger(a));
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, provider);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.4iVk3-Y0v4RT4_9IaQlp-8dZ_4fsTzIylgrPTDLrEvTHBTyVS3tgPbr2_IZfLETtiKRqCg0aQ5sh9eIsTTwB1g";
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnVerifyWhenThePublicKeyIsInvalid() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: some-alg");
        exception.expectCause(isA(InvalidKeyException.class));

        CryptoHelper crypto = mock(CryptoHelper.class);
        when(crypto.verifySignatureFor(anyString(), any(PublicKey.class), any(String.class), any(String.class), any(byte[].class)))
                .thenThrow(InvalidKeyException.class);

        ECPublicKey publicKey = mock(ECPublicKey.class);
        when(publicKey.getParams()).thenReturn(mock(ECParameterSpec.class));
        byte[] a = new byte[64];
        Arrays.fill(a, Byte.MAX_VALUE);
        when(publicKey.getParams().getOrder()).thenReturn(new BigInteger(a));
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, provider);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.4iVk3-Y0v4RT4_9IaQlp-8dZ_4fsTzIylgrPTDLrEvTHBTyVS3tgPbr2_IZfLETtiKRqCg0aQ5sh9eIsTTwB1g";
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowOnVerifyWhenTheSignatureIsNotPrepared() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectMessage("The Token's Signature resulted invalid when verified using the Algorithm: some-alg");
        exception.expectCause(isA(SignatureException.class));

        CryptoHelper crypto = mock(CryptoHelper.class);
        when(crypto.verifySignatureFor(anyString(), any(PublicKey.class), any(String.class), any(String.class), any(byte[].class)))
                .thenThrow(SignatureException.class);

        ECPublicKey publicKey = mock(ECPublicKey.class);
        when(publicKey.getParams()).thenReturn(mock(ECParameterSpec.class));
        byte[] a = new byte[64];
        Arrays.fill(a, Byte.MAX_VALUE);
        when(publicKey.getParams().getOrder()).thenReturn(new BigInteger(a));
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, provider);
        String jwt = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.4iVk3-Y0v4RT4_9IaQlp-8dZ_4fsTzIylgrPTDLrEvTHBTyVS3tgPbr2_IZfLETtiKRqCg0aQ5sh9eIsTTwB1g";
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldThrowWhenSignatureNotValidBase64() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectCause(isA(IllegalArgumentException.class));

        String jwt = "eyJhbGciOiJFUzUxMiJ9.eyJpc3MiOiJhdXRoMCJ9.MIGIAkIB4Ik8MixIeHBFIZkJjquymLzN6Q7DQr2pgw2uJ0UW726GsDVCsb4RTFeUTTrKaHZHtHPRoTuTEHCuerwvxo4+EICQgGALKocz3lL8qfH1444LNBLaOSNJp3RNkB5YHDEhQEsox21PMA9kau2TcxkOW9jGX6b9N9FhlGo0mmWFhVCR1YNg";
        ECKey key = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        Algorithm algorithm = Algorithm.ECDSA512(key);
        algorithm.verify(JWT.decode(jwt));
    }

        //Sign
    private static final String ES256Header = "eyJhbGciOiJFUzI1NiJ9";
    private static final String ES384Header = "eyJhbGciOiJFUzM4NCJ9";
    private static final String ES512Header = "eyJhbGciOiJFUzUxMiJ9";
    private static final String auth0IssPayload = "eyJpc3MiOiJhdXRoMCJ9";

    private static final byte[] ES256HeaderBytes = ES256Header.getBytes(StandardCharsets.UTF_8);
    private static final byte[] ES384HeaderBytes = ES384Header.getBytes(StandardCharsets.UTF_8);
    private static final byte[] ES512HeaderBytes = ES512Header.getBytes(StandardCharsets.UTF_8);
    private static final byte[] auth0IssPayloadBytes = auth0IssPayload.getBytes(StandardCharsets.UTF_8);


    @Test
    public void shouldDoECDSA256Signing() throws Exception {
        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        Algorithm algorithmVerify = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"));
        String jwt = asJWT(algorithm, ES256Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithmVerify.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldDoECDSA256SigningWithBothKeys() throws Exception {
        Algorithm algorithm = Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        byte[] signatureBytes = algorithm.sign(ES256HeaderBytes, auth0IssPayloadBytes);
        String jwtSignature = Base64.getUrlEncoder().withoutPadding().encodeToString(signatureBytes);
        String jwt = String.format("%s.%s.%s", ES256Header, auth0IssPayload, jwtSignature);

        assertSignaturePresent(jwt);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldDoECDSA256SigningWithProvidedPrivateKey() throws Exception {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        PrivateKey privateKey = readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC");
        PublicKey publicKey = readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        when(provider.getPrivateKey()).thenReturn((ECPrivateKey) privateKey);
        when(provider.getPublicKeyById(null)).thenReturn((ECPublicKey) publicKey);
        Algorithm algorithm = Algorithm.ECDSA256(provider);

        String jwt = asJWT(algorithm, ES256Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailOnECDSA256SigningWhenProvidedPrivateKeyIsNull() {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPrivateKey()).thenReturn(null);
        Algorithm algorithm = Algorithm.ECDSA256(provider);
        algorithm.sign(new byte[0], new byte[0]);
    }

    @Test
    public void shouldFailOnECDSA256SigningWhenUsingPublicKey() throws Exception {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        Algorithm algorithm = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"));
        algorithm.sign(new byte[0], new byte[0]);
    }

    @Test
    public void shouldDoECDSA384Signing() throws Exception {
        Algorithm algorithmSign = Algorithm.ECDSA384((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
        Algorithm algorithmVerify = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"));
        String jwt = asJWT(algorithmSign, ES384Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithmVerify.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldDoECDSA384SigningWithBothKeys() throws Exception {
        Algorithm algorithm = Algorithm.ECDSA384((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
        String jwt = asJWT(algorithm, ES384Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldDoECDSA384SigningWithProvidedPrivateKey() throws Exception {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        PrivateKey privateKey = readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC");
        PublicKey publicKey = readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC");
        when(provider.getPrivateKey()).thenReturn((ECPrivateKey) privateKey);
        when(provider.getPublicKeyById(null)).thenReturn((ECPublicKey) publicKey);
        Algorithm algorithm = Algorithm.ECDSA384(provider);

        String jwt = asJWT(algorithm, ES384Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailOnECDSA384SigningWhenProvidedPrivateKeyIsNull() {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPrivateKey()).thenReturn(null);
        Algorithm algorithm = Algorithm.ECDSA384(provider);
        algorithm.sign(new byte[0], new byte[0]);
    }

    @Test
    public void shouldFailOnECDSA384SigningWhenUsingPublicKey() throws Exception {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA384withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        Algorithm algorithm = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"));
        algorithm.sign(new byte[0], new byte[0]);
    }

    @Test
    public void shouldDoECDSA512Signing() throws Exception {
        Algorithm algorithmSign = Algorithm.ECDSA512((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));
        Algorithm algorithmVerify = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"));

        String jwt = asJWT(algorithmSign, ES512Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithmVerify.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldDoECDSA512SigningWithBothKeys() throws Exception {
        Algorithm algorithm = Algorithm.ECDSA512((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));

        String jwt = asJWT(algorithm, ES512Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithm.verify(JWT.decode(jwt));
    }


    @Test
    public void shouldDoECDSA512SigningWithProvidedPrivateKey() throws Exception {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        PrivateKey privateKey = readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC");
        PublicKey publicKey = readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        when(provider.getPrivateKey()).thenReturn((ECPrivateKey) privateKey);
        when(provider.getPublicKeyById(null)).thenReturn((ECPublicKey) publicKey);
        Algorithm algorithm = Algorithm.ECDSA512(provider);

        String jwt = asJWT(algorithm, ES512Header, auth0IssPayload);

        assertSignaturePresent(jwt);
        algorithm.verify(JWT.decode(jwt));
    }

    @Test
    public void shouldFailOnECDSA512SigningWhenProvidedPrivateKeyIsNull() {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPrivateKey()).thenReturn(null);
        Algorithm algorithm = Algorithm.ECDSA512(provider);
        algorithm.sign(new byte[0], new byte[0]);
    }

    @Test
    public void shouldFailOnECDSA512SigningWhenUsingPublicKey() throws Exception {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA512withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        Algorithm algorithm = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"));
        algorithm.sign(new byte[0], new byte[0]);
    }

    @Test
    public void shouldThrowOnSignWhenSignatureAlgorithmDoesNotExists() throws Exception {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: some-algorithm");
        exception.expectCause(isA(NoSuchAlgorithmException.class));

        CryptoHelper crypto = mock(CryptoHelper.class);
        when(crypto.createSignatureFor(anyString(), any(PrivateKey.class), any(byte[].class), any(byte[].class)))
                .thenThrow(NoSuchAlgorithmException.class);

        ECPublicKey publicKey = mock(ECPublicKey.class);
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, provider);
        algorithm.sign(ES256HeaderBytes, new byte[0]);
    }

    @Test
    public void shouldThrowOnSignWhenThePrivateKeyIsInvalid() throws Exception {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: some-algorithm");
        exception.expectCause(isA(InvalidKeyException.class));

        CryptoHelper crypto = mock(CryptoHelper.class);
        when(crypto.createSignatureFor(anyString(), any(PrivateKey.class), any(byte[].class), any(byte[].class)))
                .thenThrow(InvalidKeyException.class);

        ECPublicKey publicKey = mock(ECPublicKey.class);
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, provider);
        algorithm.sign(ES256HeaderBytes, new byte[0]);
    }

    @Test
    public void shouldThrowOnSignWhenTheSignatureIsNotPrepared() throws Exception {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: some-algorithm");
        exception.expectCause(isA(SignatureException.class));

        CryptoHelper crypto = mock(CryptoHelper.class);
        when(crypto.createSignatureFor(anyString(), any(PrivateKey.class), any(byte[].class), any(byte[].class)))
                .thenThrow(SignatureException.class);

        ECPublicKey publicKey = mock(ECPublicKey.class);
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, provider);
        algorithm.sign(ES256HeaderBytes, new byte[0]);
    }

    @Test
    public void shouldReturnNullSigningKeyIdIfCreatedWithDefaultProvider() {
        ECPublicKey publicKey = mock(ECPublicKey.class);
        ECPrivateKey privateKey = mock(ECPrivateKey.class);
        ECDSAKeyProvider provider = ECDSAAlgorithm.providerForKeys(publicKey, privateKey);
        Algorithm algorithm = new ECDSAAlgorithm("some-alg", "some-algorithm", 32, provider);

        assertThat(algorithm.getSigningKeyId(), is(nullValue()));
    }

    @Test
    public void shouldReturnSigningKeyIdFromProvider() {
        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPrivateKeyId()).thenReturn("keyId");
        Algorithm algorithm = new ECDSAAlgorithm("some-alg", "some-algorithm", 32, provider);

        assertThat(algorithm.getSigningKeyId(), is("keyId"));
    }

    @Test
    public void shouldThrowOnDERSignatureConversionIfDoesNotStartWithCorrectSequenceByte() throws Exception {
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid DER signature format.");

        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        String content256 = "eyJhbGciOiJFUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9";

        byte[] signature = algorithm256.sign(content256.getBytes(), new byte[0]);
        signature[0] = (byte) 0x02;
        algorithm256.DERToJOSE(signature);
    }

    @Test
    public void shouldThrowOnDERSignatureConversionIfDoesNotHaveExpectedLength() throws Exception {
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        byte[] derSignature = createDERSignature(32, false, false);
        int received = (int) derSignature[1];
        received--;
        derSignature[1] = (byte) received;
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid DER signature format.");

        algorithm256.DERToJOSE(derSignature);
    }

    @Test
    public void shouldThrowOnDERSignatureConversionIfRNumberDoesNotHaveExpectedLength() throws Exception {
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        byte[] derSignature = createDERSignature(32, false, false);
        derSignature[3] = (byte) 34;
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid DER signature format.");

        algorithm256.DERToJOSE(derSignature);
    }

    @Test
    public void shouldThrowOnDERSignatureConversionIfSNumberDoesNotHaveExpectedLength() throws Exception {
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        byte[] derSignature = createDERSignature(32, false, false);
        derSignature[4 + 32 + 1] = (byte) 34;
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid DER signature format.");

        algorithm256.DERToJOSE(derSignature);
    }

    @Test
    public void shouldThrowOnJOSESignatureConversionIfDoesNotHaveExpectedLength() throws Exception {
        ECPublicKey publicKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256(publicKey, (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        byte[] joseSignature = new byte[32 * 2 - 1];
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid JOSE signature format.");

        algorithm256.validateSignatureStructure(joseSignature, publicKey);
    }

    @Test
    public void shouldSignAndVerifyWithECDSA256() throws Exception {
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        String header256 = "eyJhbGciOiJFUzI1NiJ9";
        String body = "eyJpc3MiOiJhdXRoMCJ9";

        for (int i = 0; i < 10; i++) {
            String jwt = asJWT(algorithm256, header256, body);
            algorithm256.verify(JWT.decode(jwt));
        }
    }

    @Test
    public void shouldSignAndVerifyWithECDSA384() throws Exception {
        ECDSAAlgorithm algorithm384 = (ECDSAAlgorithm) Algorithm.ECDSA384((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
        String header384 = "eyJhbGciOiJFUzM4NCJ9";
        String body = "eyJpc3MiOiJhdXRoMCJ9";

        for (int i = 0; i < 10; i++) {
            String jwt = asJWT(algorithm384, header384, body);
            algorithm384.verify(JWT.decode(jwt));
        }
    }

    @Test
    public void shouldSignAndVerifyWithECDSA512() throws Exception {
        ECDSAAlgorithm algorithm512 = (ECDSAAlgorithm) Algorithm.ECDSA512((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));
        String header512 = "eyJhbGciOiJFUzUxMiJ9";
        String body = "eyJpc3MiOiJhdXRoMCJ9";

        for (int i = 0; i < 10; i++) {
            String jwt = asJWT(algorithm512, header512, body);
            algorithm512.verify(JWT.decode(jwt));
        }
    }

    @Test
    public void shouldDecodeECDSA256JOSE() throws Exception {
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));

        //Without padding
        byte[] joseSignature = createJOSESignature(32, false, false);
        byte[] derSignature = algorithm256.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 32, false, false);

        //With R padding
        joseSignature = createJOSESignature(32, true, false);
        derSignature = algorithm256.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 32, true, false);

        //With S padding
        joseSignature = createJOSESignature(32, false, true);
        derSignature = algorithm256.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 32, false, true);

        //With both paddings
        joseSignature = createJOSESignature(32, true, true);
        derSignature = algorithm256.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 32, true, true);
    }

    @Test
    public void shouldDecodeECDSA256DER() throws Exception {
        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));

        //Without padding
        byte[] derSignature = createDERSignature(32, false, false);
        byte[] joseSignature = algorithm256.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 32, false, false);

        //With R padding
        derSignature = createDERSignature(32, true, false);
        joseSignature = algorithm256.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 32, true, false);

        //With S padding
        derSignature = createDERSignature(32, false, true);
        joseSignature = algorithm256.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 32, false, true);

        //With both paddings
        derSignature = createDERSignature(32, true, true);
        joseSignature = algorithm256.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 32, true, true);
    }

    @Test
    public void shouldDecodeECDSA384JOSE() throws Exception {
        ECDSAAlgorithm algorithm384 = (ECDSAAlgorithm) Algorithm.ECDSA384((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));

        //Without padding
        byte[] joseSignature = createJOSESignature(48, false, false);
        byte[] derSignature = algorithm384.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 48, false, false);

        //With R padding
        joseSignature = createJOSESignature(48, true, false);
        derSignature = algorithm384.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 48, true, false);

        //With S padding
        joseSignature = createJOSESignature(48, false, true);
        derSignature = algorithm384.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 48, false, true);

        //With both paddings
        joseSignature = createJOSESignature(48, true, true);
        derSignature = algorithm384.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 48, true, true);
    }

    @Test
    public void shouldDecodeECDSA384DER() throws Exception {
        ECDSAAlgorithm algorithm384 = (ECDSAAlgorithm) Algorithm.ECDSA384((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));

        //Without padding
        byte[] derSignature = createDERSignature(48, false, false);
        byte[] joseSignature = algorithm384.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 48, false, false);

        //With R padding
        derSignature = createDERSignature(48, true, false);
        joseSignature = algorithm384.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 48, true, false);

        //With S padding
        derSignature = createDERSignature(48, false, true);
        joseSignature = algorithm384.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 48, false, true);

        //With both paddings
        derSignature = createDERSignature(48, true, true);
        joseSignature = algorithm384.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 48, true, true);
    }

    @Test
    public void shouldDecodeECDSA512JOSE() throws Exception {
        ECDSAAlgorithm algorithm512 = (ECDSAAlgorithm) Algorithm.ECDSA512((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));

        //Without padding
        byte[] joseSignature = createJOSESignature(66, false, false);
        byte[] derSignature = algorithm512.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 66, false, false);

        //With R padding
        joseSignature = createJOSESignature(66, true, false);
        derSignature = algorithm512.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 66, true, false);

        //With S padding
        joseSignature = createJOSESignature(66, false, true);
        derSignature = algorithm512.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 66, false, true);

        //With both paddings
        joseSignature = createJOSESignature(66, true, true);
        derSignature = algorithm512.JOSEToDER(joseSignature);
        assertValidDERSignature(derSignature, 66, true, true);
    }

    @Test
    public void shouldDecodeECDSA512DER() throws Exception {
        ECDSAAlgorithm algorithm512 = (ECDSAAlgorithm) Algorithm.ECDSA512((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));

        //Without padding
        byte[] derSignature = createDERSignature(66, false, false);
        byte[] joseSignature = algorithm512.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 66, false, false);

        //With R padding
        derSignature = createDERSignature(66, true, false);
        joseSignature = algorithm512.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 66, true, false);

        //With S padding
        derSignature = createDERSignature(66, false, true);
        joseSignature = algorithm512.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 66, false, true);

        //With both paddings
        derSignature = createDERSignature(66, true, true);
        joseSignature = algorithm512.DERToJOSE(derSignature);
        assertValidJOSESignature(joseSignature, 66, true, true);
    }


    //Test Helpers
    static void assertValidJOSESignature(byte[] joseSignature, int numberSize, boolean withRPadding, boolean withSPadding) {
        assertThat(joseSignature, is(Matchers.notNullValue()));
        assertThat(numberSize, is(IsIn.oneOf(32, 48, 66)));

        assertThat(joseSignature.length, is(numberSize * 2));

        byte[] rCopy = Arrays.copyOfRange(joseSignature, 0, numberSize);
        byte[] sCopy = Arrays.copyOfRange(joseSignature, numberSize, numberSize * 2);

        byte[] rNumber = new byte[numberSize];
        byte[] sNumber = new byte[numberSize];
        Arrays.fill(rNumber, (byte) 0x11);
        Arrays.fill(sNumber, (byte) 0x22);
        if (withRPadding) {
            rNumber[0] = (byte) 0;
        }
        if (withSPadding) {
            sNumber[0] = (byte) 0;
        }
        assertThat(Arrays.equals(rNumber, rCopy), is(true));
        assertThat(Arrays.equals(sNumber, sCopy), is(true));
    }

    static byte[] createDERSignature(int numberSize, boolean withRPadding, boolean withSPadding) {
        assertThat(numberSize, is(IsIn.oneOf(32, 48, 66)));

        int rLength = withRPadding ? numberSize - 1 : numberSize;
        int sLength = withSPadding ? numberSize - 1 : numberSize;
        int totalLength = 2 + (2 + rLength) + (2 + sLength);

        byte[] rNumber = new byte[rLength];
        byte[] sNumber = new byte[sLength];
        Arrays.fill(rNumber, (byte) 0x11);
        Arrays.fill(sNumber, (byte) 0x22);

        byte[] derSignature;
        int offset = 0;
        if (totalLength > 0x7f) {
            totalLength++;
            derSignature = new byte[totalLength];
            //Start sequence and sign
            derSignature[offset++] = (byte) 0x30;
            derSignature[offset++] = (byte) 0x81;
        } else {
            derSignature = new byte[totalLength];
            //Start sequence
            derSignature[offset++] = (byte) 0x30;
        }

        //Sequence length
        derSignature[offset++] = (byte) (totalLength - offset);

        //R number
        derSignature[offset++] = (byte) 0x02;
        derSignature[offset++] = (byte) rLength;
        System.arraycopy(rNumber, 0, derSignature, offset, rLength);
        offset += rLength;

        //S number
        derSignature[offset++] = (byte) 0x02;
        derSignature[offset++] = (byte) sLength;
        System.arraycopy(sNumber, 0, derSignature, offset, sLength);

        return derSignature;
    }

    static byte[] createJOSESignature(int numberSize, boolean withRPadding, boolean withSPadding) {
        assertThat(numberSize, is(IsIn.oneOf(32, 48, 66)));

        byte[] rNumber = new byte[numberSize];
        byte[] sNumber = new byte[numberSize];
        Arrays.fill(rNumber, (byte) 0x11);
        Arrays.fill(sNumber, (byte) 0x22);
        if (withRPadding) {
            rNumber[0] = (byte) 0;
        }
        if (withSPadding) {
            sNumber[0] = (byte) 0;
        }
        byte[] joseSignature = new byte[numberSize * 2];
        System.arraycopy(rNumber, 0, joseSignature, 0, numberSize);
        System.arraycopy(sNumber, 0, joseSignature, numberSize, numberSize);
        return joseSignature;
    }

    static void assertValidDERSignature(byte[] derSignature, int numberSize, boolean withRPadding, boolean withSPadding) {
        assertThat(derSignature, is(Matchers.notNullValue()));
        assertThat(numberSize, is(IsIn.oneOf(32, 48, 66)));

        int rLength = withRPadding ? numberSize - 1 : numberSize;
        int sLength = withSPadding ? numberSize - 1 : numberSize;
        int totalLength = 2 + (2 + rLength) + (2 + sLength);
        int offset = 0;

        //Start sequence
        assertThat(derSignature[offset++], is((byte) 0x30));
        if (totalLength > 0x7f) {
            //Add sign before sequence length
            totalLength++;
            assertThat(derSignature[offset++], is((byte) 0x81));
        }
        //Sequence length
        assertThat(derSignature[offset++], is((byte) (totalLength - offset)));

        //R number
        assertThat(derSignature[offset++], is((byte) 0x02));
        assertThat(derSignature[offset++], is((byte) rLength));
        byte[] rCopy = Arrays.copyOfRange(derSignature, offset, offset + rLength);
        offset += rLength;

        //S number
        assertThat(derSignature[offset++], is((byte) 0x02));
        assertThat(derSignature[offset++], is((byte) sLength));
        byte[] sCopy = Arrays.copyOfRange(derSignature, offset, offset + sLength);


        byte[] rNumber = new byte[rLength];
        byte[] sNumber = new byte[sLength];
        Arrays.fill(rNumber, (byte) 0x11);
        Arrays.fill(sNumber, (byte) 0x22);
        assertThat(Arrays.equals(rNumber, rCopy), is(true));
        assertThat(Arrays.equals(sNumber, sCopy), is(true));
        assertThat(derSignature.length, is(totalLength));
    }

    @Test
    public void shouldBeEqualSignatureMethodDecodeResults() throws Exception {
        // signatures are not deterministic in value, so instead of directly comparing the signatures,
        // check that both sign(..) methods can be used to create a jwt which can be
        // verified
        Algorithm algorithm = Algorithm.ECDSA256((ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"), (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));

        String header = "eyJhbGciOiJFUzI1NiJ9";
        String payload = "eyJpc3MiOiJhdXRoMCJ9";

        byte[] headerBytes = header.getBytes(StandardCharsets.UTF_8);
        byte[] payloadBytes = payload.getBytes(StandardCharsets.UTF_8);

        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        bout.write(headerBytes);
        bout.write('.');
        bout.write(payloadBytes);

        String jwtSignature1 = Base64.getUrlEncoder().withoutPadding().encodeToString(algorithm.sign(bout.toByteArray()));
        String jwt1 = String.format("%s.%s.%s", header, payload, jwtSignature1);

        algorithm.verify(JWT.decode(jwt1));

        String jwtSignature2 = Base64.getUrlEncoder().withoutPadding().encodeToString(algorithm.sign(headerBytes, payloadBytes));
        String jwt2 = String.format("%s.%s.%s", header, payload, jwtSignature2);

        algorithm.verify(JWT.decode(jwt2));
    }

    /**
     * Test deprecated signing method error handling.
     *
     * @see {@linkplain #shouldFailOnECDSA256SigningWhenProvidedPrivateKeyIsNull}
     * @throws Exception expected exception
     */

    @Test
    public void shouldFailOnECDSA256SigningWithDeprecatedMethodWhenProvidedPrivateKeyIsNull() {
        exception.expect(SignatureGenerationException.class);
        exception.expectMessage("The Token's Signature couldn't be generated when signing using the Algorithm: SHA256withECDSA");
        exception.expectCause(isA(IllegalStateException.class));
        exception.expectCause(hasMessage(is("The given Private Key is null.")));

        ECDSAKeyProvider provider = mock(ECDSAKeyProvider.class);
        when(provider.getPrivateKey()).thenReturn(null);
        Algorithm algorithm = Algorithm.ECDSA256(provider);
        algorithm.sign(new byte[0]);
    }

    @Test
    public void invalidECDSA256SignatureShouldFailTokenVerification() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectCause(isA(SignatureException.class));

        String jwtWithInvalidSig = "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTUxNjIzOTAyMn0._____wAAAAD__________7zm-q2nF56E87nKwvxjJVH_____AAAAAP__________vOb6racXnoTzucrC_GMlUQ";

        ECKey key256 = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECKey key384 = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC");
        ECKey key512 = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        JWTVerifier verifier256 = JWT.require(Algorithm.ECDSA256(key256)).build();
        JWTVerifier verifier384 = JWT.require(Algorithm.ECDSA256(key384)).build();
        JWTVerifier verifier512 = JWT.require(Algorithm.ECDSA256(key512)).build();
        verifier256.verify(jwtWithInvalidSig);
        verifier384.verify(jwtWithInvalidSig);
        verifier512.verify(jwtWithInvalidSig);
    }

    @Test
    public void emptyECDSA256SignatureShouldFailTokenVerification() throws Exception {
        exception.expect(SignatureVerificationException.class);
        exception.expectCause(isA(SignatureException.class));

        String jwtWithInvalidSig = "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTUxNjIzOTAyMn0.AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";

        ECKey key256 = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECKey key384 = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC");
        ECKey key512 = (ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC");
        JWTVerifier verifier256 = JWT.require(Algorithm.ECDSA256(key256)).build();
        JWTVerifier verifier384 = JWT.require(Algorithm.ECDSA256(key384)).build();
        JWTVerifier verifier512 = JWT.require(Algorithm.ECDSA256(key512)).build();
        verifier256.verify(jwtWithInvalidSig);
        verifier384.verify(jwtWithInvalidSig);
        verifier512.verify(jwtWithInvalidSig);
    }

    @Test
    public void signatureWithAllZerosShouldFail() throws Exception {
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid signature format.");

        ECPublicKey pubKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");

        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256(pubKey, (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
        byte[] signatureBytes = new byte[64];
        algorithm256.validateSignatureStructure(signatureBytes, pubKey);
    }

    @Test
    public void signatureWithRZeroShouldFail() throws Exception {
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid signature format.");

        ECPublicKey publicKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECPrivateKey privateKey = (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC");

        String signedJwt = JWT.create().sign(Algorithm.ECDSA256(publicKey, privateKey));

        String[] chunks = signedJwt.split("\\.");
        byte[] signature = Base64.getUrlDecoder().decode(chunks[2]);

        byte[] sigWithBlankR = new byte[signature.length];
        for (int i = 0; i < signature.length; i++) {
            if (i < signature.length / 2) {
                sigWithBlankR[i] = 0;
            } else {
                sigWithBlankR[i] = signature[i];
            }
        }

        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256(publicKey, privateKey);
        algorithm256.validateSignatureStructure(sigWithBlankR, publicKey);
    }

    @Test
    public void signatureWithSZeroShouldFail() throws Exception {
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid signature format.");

        ECPublicKey publicKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECPrivateKey privateKey = (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC");

        String signedJwt = JWT.create().sign(Algorithm.ECDSA256(publicKey, privateKey));

        String[] chunks = signedJwt.split("\\.");
        byte[] signature = Base64.getUrlDecoder().decode(chunks[2]);

        byte[] sigWithBlankS = new byte[signature.length];
        for (int i = 0; i < signature.length; i++) {
            if (i < signature.length / 2) {
                sigWithBlankS[i] = signature[i];
            } else {
                sigWithBlankS[i] = 0;
            }
        }

        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256(publicKey, privateKey);
        algorithm256.validateSignatureStructure(sigWithBlankS, publicKey);
    }

    @Test
    public void signatureWithRValueNotLessThanOrderShouldFail() throws Exception {
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid signature format.");

        ECPublicKey publicKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECPrivateKey privateKey = (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC");

        String signedJwt = JWT.create().sign(Algorithm.ECDSA256(publicKey, privateKey));
        String jwtWithInvalidSig = signedJwt.substring(0, signedJwt.lastIndexOf('.') + 1) + "_____wAAAAD__________7zm-q2nF56E87nKwvxjJVH_____AAAAAP__________vOb6racXnoTzucrC_GMlUQ";

        String[] chunks = jwtWithInvalidSig.split("\\.");
        byte[] invalidSignature = Base64.getUrlDecoder().decode(chunks[2]);

        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256(publicKey, privateKey);
        algorithm256.validateSignatureStructure(invalidSignature, publicKey);
    }

    @Test
    public void signatureWithSValueNotLessThanOrderShouldFail() throws Exception {
        exception.expect(SignatureException.class);
        exception.expectMessage("Invalid signature format.");

        ECPublicKey publicKey = (ECPublicKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC");
        ECPrivateKey privateKey = (ECPrivateKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC");

        String signedJwt = JWT.create().sign(Algorithm.ECDSA256(publicKey, privateKey));
        String jwtWithInvalidSig = signedJwt.substring(0, signedJwt.lastIndexOf('.') + 1) + "_____wAAAAD__________7zm-q2nF56E87nKwvxjJVH_____AAAAAP__________vOb6racXnoTzucrC_GMlUQ";

        String[] chunks = jwtWithInvalidSig.split("\\.");
        byte[] invalidSignature = Base64.getUrlDecoder().decode(chunks[2]);
        invalidSignature[0] = Byte.MAX_VALUE;

        ECDSAAlgorithm algorithm256 = (ECDSAAlgorithm) Algorithm.ECDSA256(publicKey, privateKey);
        algorithm256.validateSignatureStructure(invalidSignature, publicKey);
    }
}