Moved the code from Spring Cloud Security

spring-cloud-openfeign-core/pom.xml

@@ -119,6 +119,11 @@
 			<artifactId>okhttp</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.security.oauth.boot</groupId>
+			<artifactId>spring-security-oauth2-autoconfigure</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-autoconfigure-processor</artifactId>

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/FeignAutoConfiguration.java

@@ -27,6 +27,7 @@
 
 import feign.Client;
 import feign.Feign;
+import feign.RequestInterceptor;
 import feign.httpclient.ApacheHttpClient;
 import feign.okhttp.OkHttpClient;
 import okhttp3.ConnectionPool;
@@ -39,6 +40,7 @@
 import org.apache.http.impl.client.CloseableHttpClient;
 
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
@@ -48,11 +50,14 @@
 import org.springframework.cloud.commons.httpclient.ApacheHttpClientFactory;
 import org.springframework.cloud.commons.httpclient.OkHttpClientConnectionPoolFactory;
 import org.springframework.cloud.commons.httpclient.OkHttpClientFactory;
+import org.springframework.cloud.openfeign.security.OAuth2FeignRequestInterceptor;
 import org.springframework.cloud.openfeign.support.DefaultGzipDecoderConfiguration;
 import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.security.oauth2.client.OAuth2ClientContext;
+import org.springframework.security.oauth2.client.resource.OAuth2ProtectedResourceDetails;
 
 /**
  * @author Spencer Gibb
@@ -209,4 +214,19 @@ public Client feignClient(okhttp3.OkHttpClient client) {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass(OAuth2ClientContext.class)
+	@ConditionalOnProperty("feign.oauth2.enabled")
+	protected static class Oauth2FeignConfiguration {
+
+		@Bean
+		@ConditionalOnMissingBean(OAuth2FeignRequestInterceptor.class)
+		@ConditionalOnBean({ OAuth2ClientContext.class, OAuth2ProtectedResourceDetails.class })
+		public RequestInterceptor oauth2FeignRequestInterceptor(OAuth2ClientContext oAuth2ClientContext,
+				OAuth2ProtectedResourceDetails resource) {
+			return new OAuth2FeignRequestInterceptor(oAuth2ClientContext, resource);
+		}
+
+	}
+
 }

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/security/OAuth2FeignRequestInterceptor.java

@@ -0,0 +1,182 @@
+/*
+ * Copyright 2015-2019 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.cloud.openfeign.security;
+
+import java.util.Arrays;
+
+import feign.RequestInterceptor;
+import feign.RequestTemplate;
+
+import org.springframework.security.oauth2.client.OAuth2ClientContext;
+import org.springframework.security.oauth2.client.http.AccessTokenRequiredException;
+import org.springframework.security.oauth2.client.resource.OAuth2ProtectedResourceDetails;
+import org.springframework.security.oauth2.client.resource.UserRedirectRequiredException;
+import org.springframework.security.oauth2.client.token.AccessTokenProvider;
+import org.springframework.security.oauth2.client.token.AccessTokenProviderChain;
+import org.springframework.security.oauth2.client.token.AccessTokenRequest;
+import org.springframework.security.oauth2.client.token.grant.client.ClientCredentialsAccessTokenProvider;
+import org.springframework.security.oauth2.client.token.grant.code.AuthorizationCodeAccessTokenProvider;
+import org.springframework.security.oauth2.client.token.grant.implicit.ImplicitAccessTokenProvider;
+import org.springframework.security.oauth2.client.token.grant.password.ResourceOwnerPasswordAccessTokenProvider;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+
+/**
+ * Pre-defined custom RequestInterceptor for Feign Requests. It uses the
+ * {@link OAuth2ClientContext OAuth2ClientContext} provided from the environment and
+ * construct a new header on the request before it is made by Feign.
+ *
+ * @author Joao Pedro Evangelista
+ * @author Tim Ysewyn
+ * @since 3.0.0
+ */
+public class OAuth2FeignRequestInterceptor implements RequestInterceptor {
+
+	/**
+	 * The name of the token.
+	 */
+	public static final String BEARER = "Bearer";
+
+	/**
+	 * The name of the header.
+	 */
+	public static final String AUTHORIZATION = "Authorization";
+
+	private final OAuth2ClientContext oAuth2ClientContext;
+
+	private final OAuth2ProtectedResourceDetails resource;
+
+	private final String tokenType;
+
+	private final String header;
+
+	private AccessTokenProvider accessTokenProvider = new AccessTokenProviderChain(Arrays.<AccessTokenProvider>asList(
+			new AuthorizationCodeAccessTokenProvider(), new ImplicitAccessTokenProvider(),
+			new ResourceOwnerPasswordAccessTokenProvider(), new ClientCredentialsAccessTokenProvider()));
+
+	/**
+	 * Default constructor which uses the provided OAuth2ClientContext and Bearer tokens
+	 * within Authorization header.
+	 * @param oAuth2ClientContext provided context
+	 * @param resource type of resource to be accessed
+	 */
+	public OAuth2FeignRequestInterceptor(OAuth2ClientContext oAuth2ClientContext,
+			OAuth2ProtectedResourceDetails resource) {
+		this(oAuth2ClientContext, resource, BEARER, AUTHORIZATION);
+	}
+
+	/**
+	 * Fully customizable constructor for changing token type and header name, in cases of
+	 * Bearer and Authorization is not the default such as "bearer", "authorization".
+	 * @param oAuth2ClientContext current oAuth2 Context
+	 * @param resource type of resource to be accessed
+	 * @param tokenType type of token e.g. "token", "Bearer"
+	 * @param header name of the header e.g. "Authorization", "authorization"
+	 */
+	public OAuth2FeignRequestInterceptor(OAuth2ClientContext oAuth2ClientContext,
+			OAuth2ProtectedResourceDetails resource, String tokenType, String header) {
+		this.oAuth2ClientContext = oAuth2ClientContext;
+		this.resource = resource;
+		this.tokenType = tokenType;
+		this.header = header;
+	}
+
+	/**
+	 * Create a template with the header of provided name and extracted extract.
+	 *
+	 * @see RequestInterceptor#apply(RequestTemplate)
+	 */
+	@Override
+	public void apply(RequestTemplate template) {
+		template.header(header); // Clears out the header, no "clear" method available.
+		template.header(header, extract(tokenType));
+	}
+
+	/**
+	 * Extracts the token extract id the access token exists or returning an empty extract
+	 * if there is no one on the context it may occasionally causes Unauthorized response
+	 * since the token extract is empty.
+	 * @param tokenType type name of token
+	 * @return token value from context if it exists otherwise empty String
+	 */
+	protected String extract(String tokenType) {
+		OAuth2AccessToken accessToken = getToken();
+		return String.format("%s %s", tokenType, accessToken.getValue());
+	}
+
+	/**
+	 * Extract the access token within the request or try to acquire a new one by
+	 * delegating it to {@link #acquireAccessToken()}.
+	 * @return valid token
+	 */
+	public OAuth2AccessToken getToken() {
+
+		OAuth2AccessToken accessToken = oAuth2ClientContext.getAccessToken();
+		if (accessToken == null || accessToken.isExpired()) {
+			try {
+				accessToken = acquireAccessToken();
+			}
+			catch (UserRedirectRequiredException e) {
+				oAuth2ClientContext.setAccessToken(null);
+				String stateKey = e.getStateKey();
+				if (stateKey != null) {
+					Object stateToPreserve = e.getStateToPreserve();
+					if (stateToPreserve == null) {
+						stateToPreserve = "NONE";
+					}
+					oAuth2ClientContext.setPreservedState(stateKey, stateToPreserve);
+				}
+				throw e;
+			}
+		}
+		return accessToken;
+	}
+
+	/**
+	 * Try to acquire the token using a access token provider.
+	 * @return valid access token
+	 * @throws UserRedirectRequiredException in case the user needs to be redirected to an
+	 * approval page or login page
+	 */
+	protected OAuth2AccessToken acquireAccessToken() throws UserRedirectRequiredException {
+		AccessTokenRequest tokenRequest = oAuth2ClientContext.getAccessTokenRequest();
+		if (tokenRequest == null) {
+			throw new AccessTokenRequiredException(
+					"Cannot find valid context on request for resource '" + resource.getId() + "'.", resource);
+		}
+		String stateKey = tokenRequest.getStateKey();
+		if (stateKey != null) {
+			tokenRequest.setPreservedState(oAuth2ClientContext.removePreservedState(stateKey));
+		}
+		OAuth2AccessToken existingToken = oAuth2ClientContext.getAccessToken();
+		if (existingToken != null) {
+			oAuth2ClientContext.setAccessToken(existingToken);
+		}
+		OAuth2AccessToken obtainableAccessToken;
+		obtainableAccessToken = accessTokenProvider.obtainAccessToken(resource, tokenRequest);
+		if (obtainableAccessToken == null || obtainableAccessToken.getValue() == null) {
+			throw new IllegalStateException(
+					" Access token provider returned a null token, which is illegal according to the contract.");
+		}
+		oAuth2ClientContext.setAccessToken(obtainableAccessToken);
+		return obtainableAccessToken;
+	}
+
+	public void setAccessTokenProvider(AccessTokenProvider accessTokenProvider) {
+		this.accessTokenProvider = accessTokenProvider;
+	}
+
+}

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/security/MockAccessTokenProvider.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2015-2015 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.cloud.openfeign.security;
+
+import org.springframework.security.access.AccessDeniedException;
+import org.springframework.security.oauth2.client.resource.OAuth2ProtectedResourceDetails;
+import org.springframework.security.oauth2.client.resource.UserApprovalRequiredException;
+import org.springframework.security.oauth2.client.resource.UserRedirectRequiredException;
+import org.springframework.security.oauth2.client.token.AccessTokenProvider;
+import org.springframework.security.oauth2.client.token.AccessTokenRequest;
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.security.oauth2.common.OAuth2RefreshToken;
+
+/**
+ * Mocks the access token provider
+ *
+ * @author Mihhail Verhovtsov
+ */
+public class MockAccessTokenProvider implements AccessTokenProvider {
+
+	private OAuth2AccessToken token;
+
+	public MockAccessTokenProvider(OAuth2AccessToken token) {
+		this.token = token;
+	}
+
+	@Override
+	public OAuth2AccessToken obtainAccessToken(OAuth2ProtectedResourceDetails oAuth2ProtectedResourceDetails,
+			AccessTokenRequest accessTokenRequest)
+			throws UserRedirectRequiredException, UserApprovalRequiredException, AccessDeniedException {
+		return token;
+	}
+
+	@Override
+	public boolean supportsResource(OAuth2ProtectedResourceDetails oAuth2ProtectedResourceDetails) {
+		return true;
+	}
+
+	@Override
+	public OAuth2AccessToken refreshAccessToken(OAuth2ProtectedResourceDetails oAuth2ProtectedResourceDetails,
+			OAuth2RefreshToken oAuth2RefreshToken, AccessTokenRequest accessTokenRequest)
+			throws UserRedirectRequiredException {
+		return null;
+	}
+
+	@Override
+	public boolean supportsRefresh(OAuth2ProtectedResourceDetails oAuth2ProtectedResourceDetails) {
+		return false;
+	}
+
+}

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/security/MockOAuth2AccessToken.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2015-2015 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.cloud.openfeign.security;
+
+import java.util.Date;
+import java.util.Map;
+import java.util.Set;
+
+import org.springframework.security.oauth2.common.OAuth2AccessToken;
+import org.springframework.security.oauth2.common.OAuth2RefreshToken;
+
+/**
+ * Mocks the OAuth2 access token
+ *
+ * @author Mihhail Verhovtsov
+ */
+public class MockOAuth2AccessToken implements OAuth2AccessToken {
+
+	private String value;
+
+	public MockOAuth2AccessToken(String value) {
+		this.value = value;
+	}
+
+	@Override
+	public Map<String, Object> getAdditionalInformation() {
+		return null;
+	}
+
+	@Override
+	public Set<String> getScope() {
+		return null;
+	}
+
+	@Override
+	public OAuth2RefreshToken getRefreshToken() {
+		return null;
+	}
+
+	@Override
+	public String getTokenType() {
+		return null;
+	}
+
+	@Override
+	public boolean isExpired() {
+		return false;
+	}
+
+	@Override
+	public Date getExpiration() {
+		return null;
+	}
+
+	@Override
+	public int getExpiresIn() {
+		return 0;
+	}
+
+	@Override
+	public String getValue() {
+		return value;
+	}
+
+}