Introduce proxy support for backend oauth security

modules/core/src/main/java/org/apache/synapse/endpoints/OAuthConfiguredHTTPEndpoint.java

@@ -64,10 +64,10 @@ public void send(MessageContext synCtx) {
 
         } catch (AuthException e) {
             handleError(synCtx,
-                    "Could not generate access token for oauth configured http endpoint " + this.getName(), e);
+                    "Could not generate access token for oauth configured http endpoint " + this.getName() + ".", e);
         } catch (AxisFault axisFault) {
             handleError(synCtx,
-                    "Error cloning the message context for oauth configured http endpoint " + this.getName(),
+                    "Error cloning the message context for oauth configured http endpoint " + this.getName() + ".",
                     axisFault);
         }
     }

modules/core/src/main/java/org/apache/synapse/endpoints/ProxyConfigs.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2024, WSO2 LLC. (https://www.wso2.com/).
+ *
+ * WSO2 LLC. licenses this file to you under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.synapse.endpoints;
+
+/**
+ * This class represents a model for proxy configurations which is used for the OAuth authentication of endpoints
+ */
+public class ProxyConfigs {
+    private String proxyHost;
+    private String proxyPort;
+    private String proxyUsername;
+    private String proxyPassword;
+    private String proxyProtocol;
+    private boolean proxyEnabled;
+
+    public void setProxyEnabled(boolean proxyEnabled) {
+        this.proxyEnabled = proxyEnabled;
+    }
+
+    public void setProxyHost(String proxyHost) {
+        this.proxyHost = proxyHost;
+    }
+
+    public void setProxyPort(String proxyPort) {
+        this.proxyPort = proxyPort;
+    }
+
+    public void setProxyUsername(String proxyUsername) {
+        this.proxyUsername = proxyUsername;
+    }
+
+    public void setProxyPassword(String proxyPassword) {
+        this.proxyPassword = proxyPassword;
+    }
+
+    public void setProxyProtocol(String proxyProtocol) {
+        this.proxyProtocol = proxyProtocol;
+    }
+
+    public boolean isProxyEnabled() {
+        return proxyEnabled;
+    }
+
+    public String getProxyHost() {
+        return proxyHost;
+    }
+
+    public String getProxyPort() {
+        return proxyPort;
+    }
+
+    public String getProxyUsername() {
+        return proxyUsername;
+    }
+
+    public String getProxyPassword() {
+        return proxyPassword;
+    }
+
+    public String getProxyProtocol() {
+        return proxyProtocol;
+    }
+}
+
+

modules/core/src/main/java/org/apache/synapse/endpoints/auth/AuthConstants.java

@@ -87,4 +87,12 @@ public class AuthConstants {
     public static final String BASIC_AUTH_USERNAME = "username";
     public static final String BASIC_AUTH_PASSWORD = "password";
 
+    public static final String PROXY_CONFIGS = "proxyConfigs";
+    public static final String PROXY_HOST = "proxyHost";
+    public static final String PROXY_PORT = "proxyPort";
+    public static final String PROXY_USERNAME = "proxyUsername";
+    public static final String PROXY_PASSWORD = "proxyPassword";
+    public static final String OAUTH_PROXY_PROTOCOL = "proxyProtocol";
+
+    public static final String HTTPS_PROTOCOL = "https";
 }

modules/core/src/main/java/org/apache/synapse/endpoints/auth/oauth/AuthorizationCodeHandler.java

@@ -23,6 +23,7 @@
 import org.apache.commons.lang.StringUtils;
 import org.apache.synapse.MessageContext;
 import org.apache.synapse.SynapseConstants;
+import org.apache.synapse.endpoints.ProxyConfigs;
 import org.apache.synapse.endpoints.auth.AuthConstants;
 import org.apache.synapse.endpoints.auth.AuthException;
 
@@ -35,13 +36,12 @@ public class AuthorizationCodeHandler extends OAuthHandler {
 
     private final String refreshToken;
 
-    public AuthorizationCodeHandler(String tokenApiUrl, String clientId, String clientSecret,
-                                    String refreshToken, String authMode, int connectionTimeout,
-                                    int connectionRequestTimeout, int socketTimeout,
-                                    TokenCacheProvider tokenCacheProvider) {
+    public AuthorizationCodeHandler(String tokenApiUrl, String clientId, String clientSecret, String refreshToken,
+            String authMode, int connectionTimeout, int connectionRequestTimeout, int socketTimeout,
+            TokenCacheProvider tokenCacheProvider, ProxyConfigs proxyConfigs) {
 
-        super(tokenApiUrl, clientId, clientSecret, authMode, connectionTimeout, connectionRequestTimeout,
-                socketTimeout, tokenCacheProvider);
+        super(tokenApiUrl, clientId, clientSecret, authMode, connectionTimeout, connectionRequestTimeout, socketTimeout,
+                tokenCacheProvider,proxyConfigs);
         this.refreshToken = refreshToken;
     }
 

modules/core/src/main/java/org/apache/synapse/endpoints/auth/oauth/ClientCredentialsHandler.java

@@ -23,6 +23,7 @@
 import org.apache.commons.lang.StringUtils;
 import org.apache.synapse.MessageContext;
 import org.apache.synapse.SynapseConstants;
+import org.apache.synapse.endpoints.ProxyConfigs;
 import org.apache.synapse.endpoints.auth.AuthConstants;
 import org.apache.synapse.endpoints.auth.AuthException;
 
@@ -34,11 +35,11 @@
 public class ClientCredentialsHandler extends OAuthHandler {
 
     public ClientCredentialsHandler(String tokenApiUrl, String clientId, String clientSecret, String authMode,
-                                    int connectionTimeout, int connectionRequestTimeout, int socketTimeout,
-                                    TokenCacheProvider tokenCacheProvider) {
+            int connectionTimeout, int connectionRequestTimeout, int socketTimeout,
+            TokenCacheProvider tokenCacheProvider, ProxyConfigs proxyConfigs) {
 
         super(tokenApiUrl, clientId, clientSecret, authMode, connectionTimeout, connectionRequestTimeout, socketTimeout,
-                tokenCacheProvider);
+                tokenCacheProvider, proxyConfigs);
     }
 
     @Override