Add JWKContextJWKSource

Issue: gh-5330

oauth2/oauth2-jose/src/main/java/org/springframework/security/oauth2/jwt/JWKContextJWKSource.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      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 org.springframework.security.oauth2.jwt;
+
+import com.nimbusds.jose.jwk.JWK;
+import com.nimbusds.jose.jwk.JWKSelector;
+import com.nimbusds.jose.jwk.source.JWKSource;
+
+import java.util.List;
+
+/**
+ * A {@link JWKSource} used for reactive applications that returns the {@link JWK} from the {@link JWKContext}.
+ *
+ * <p>
+ * The Nimbus {@link JWKSource} is a blocking API which means the {@link JWK} cannot be resolved using code that blocks.
+ * This means that the JWK Set could not be retrieved from HTTP endpoint. To work around this the {@link JWK} is
+ * resolved in the {@link ReactiveJwtDecoder} and provided via the {@link JWKContext}.
+ * </p>
+ *
+ * @author Rob Winch
+ * @since 5.1
+ */
+class JWKContextJWKSource implements JWKSource<JWKContext> {
+
+	@Override
+	public List<JWK> get(JWKSelector jwkSelector, JWKContext context) {
+		return context.getJwkList();
+	}
+}

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

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      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 org.springframework.security.oauth2.jwt;
+
+import com.nimbusds.jose.jwk.JWK;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.mock;
+
+/**
+ * @author Rob Winch
+ * @since 5.1
+ */
+public class JWKContextJWKSourceTests {
+	private JWKContextJWKSource source = new JWKContextJWKSource();
+
+	@Test
+	public void getWhenKeysNotEmptyThenContainsKeys() {
+		JWK key = mock(JWK.class);
+		JWKContext jwkContext = new JWKContext(Arrays.asList(key));
+
+		assertThat(this.source.get(null, jwkContext)).containsOnly(key);
+	}
+
+}