Test NimbusJwtEncoder & NimbusJwtDecoder symmetrically

This test encodes an JWT with NimbusJwtEncoder, and then decodes it with
NimbusJwtDecoder.

This test will fail when NimbusJwtEncoder emits a JWT with a wrong `typ'
parameter in the header, as NimbusJwtDecoder validates the JWT with
JwtTypeValidator by default.  It may be beneficial for finding out other
similiar bugs too.

Signed-off-by: Ziqin Wang <ziqin@wangziqin.net>

oauth2/oauth2-jose/src/test/java/org/springframework/security/oauth2/jwt/NimbusJwtEncoderDecoderTests.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2004-present the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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 org.springframework.security.oauth2.jwt;
+
+import java.security.GeneralSecurityException;
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.interfaces.ECPrivateKey;
+import java.security.interfaces.ECPublicKey;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.interfaces.RSAPublicKey;
+import java.security.spec.ECGenParameterSpec;
+import java.util.Objects;
+import java.util.Set;
+
+import javax.crypto.KeyGenerator;
+import javax.crypto.SecretKey;
+
+import com.nimbusds.jose.JOSEException;
+import com.nimbusds.jose.crypto.impl.ECDSA;
+import com.nimbusds.jose.jwk.Curve;
+import com.nimbusds.jose.jwk.ECKey;
+import com.nimbusds.jose.jwk.JWK;
+import com.nimbusds.jose.jwk.JWKSet;
+import com.nimbusds.jose.jwk.KeyOperation;
+import com.nimbusds.jose.jwk.KeyUse;
+import com.nimbusds.jose.jwk.source.ImmutableJWKSet;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.security.oauth2.jose.jws.SignatureAlgorithm;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Use {@link NimbusJwtDecoder} to decode JWT's encoded with {@link NimbusJwtEncoder}
+ *
+ * @author Ziqin Wang
+ */
+public class NimbusJwtEncoderDecoderTests {
+
+	@Test
+	public void encodeAndDecodeHS256() throws GeneralSecurityException {
+		KeyGenerator keyGenerator = KeyGenerator.getInstance("HmacSHA256");
+		SecretKey secretKey = keyGenerator.generateKey();
+
+		NimbusJwtEncoder jwtEncoder = NimbusJwtEncoder.withSecretKey(secretKey).build();
+		JwtClaimsSet claims = TestJwtClaimsSets.jwtClaimsSet().build();
+		String jwt = jwtEncoder.encode(JwtEncoderParameters.from(claims)).getTokenValue();
+
+		NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withSecretKey(secretKey).build();
+		Jwt decodedJwt = jwtDecoder.decode(jwt);
+
+		assertThat(decodedJwt.getSubject()).isEqualTo("subject");
+	}
+
+	@Test
+	public void encodeAndDecodeRS256() throws GeneralSecurityException {
+		KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
+		keyPairGenerator.initialize(2048);
+		KeyPair keyPair = keyPairGenerator.generateKeyPair();
+		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
+		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
+
+		NimbusJwtEncoder jwtEncoder = NimbusJwtEncoder.withKeyPair(publicKey, privateKey).build();
+		JwtClaimsSet claims = TestJwtClaimsSets.jwtClaimsSet().build();
+		String jwt = jwtEncoder.encode(JwtEncoderParameters.from(claims)).getTokenValue();
+
+		NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withPublicKey(publicKey).build();
+		Jwt decodedJwt = jwtDecoder.decode(jwt);
+
+		assertThat(decodedJwt.getSubject()).isEqualTo("subject");
+	}
+
+	@Test
+	public void encodeAndDecodeES256() throws GeneralSecurityException, JOSEException {
+		KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");
+		keyPairGenerator.initialize(new ECGenParameterSpec("secp256r1"));
+		KeyPair keyPair = keyPairGenerator.generateKeyPair();
+		ECPublicKey publicKey = (ECPublicKey) keyPair.getPublic();
+		ECPrivateKey privateKey = (ECPrivateKey) keyPair.getPrivate();
+
+		NimbusJwtEncoder jwtEncoder = NimbusJwtEncoder.withKeyPair(publicKey, privateKey).build();
+		JwtClaimsSet claims = TestJwtClaimsSets.jwtClaimsSet().build();
+		String jwt = jwtEncoder.encode(JwtEncoderParameters.from(claims)).getTokenValue();
+
+		Curve curve = Curve.forECParameterSpec(publicKey.getParams());
+		JWK jwk = new ECKey.Builder(curve, publicKey).keyOperations(Set.of(KeyOperation.VERIFY))
+			.keyUse(KeyUse.SIGNATURE)
+			.algorithm(ECDSA.resolveAlgorithm(curve))
+			.keyIDFromThumbprint()
+			.build();
+		NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withJwkSource(new ImmutableJWKSet<>(new JWKSet(jwk)))
+			.jwsAlgorithm(Objects.requireNonNull(SignatureAlgorithm.from(jwk.getAlgorithm().getName())))
+			.build();
+		Jwt decodedJwt = jwtDecoder.decode(jwt);
+
+		assertThat(decodedJwt.getSubject()).isEqualTo("subject");
+	}
+
+}