feign_client_impl | error handling with other grant types.

auth_token_generator/src/main/java/io/entgra/auth_token_getter/exceptions/ErrorResponse.java

@@ -0,0 +1,19 @@
+package io.entgra.auth_token_getter.exceptions;
+
+import lombok.Data;
+
+@Data
+public class ErrorResponse {
+
+    private int code;
+    private String description;
+    private String message;
+
+    public static ErrorResponse createErrorResponse(int code, String message, String description) {
+        ErrorResponse errorResponse = new ErrorResponse();
+        errorResponse.setCode(code);
+        errorResponse.setMessage(message);
+        errorResponse.setDescription(description);
+        return errorResponse;
+    }
+}

auth_token_generator/src/main/java/io/entgra/auth_token_getter/service/TokenService.java

@@ -12,11 +12,12 @@ import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.Map;
 
+import static io.entgra.auth_token_getter.exceptions.ErrorResponse.createErrorResponse;
+
 @Slf4j
 @Component
 public class TokenService {
 
-
     @Autowired
     private AuthFeignClient authFeignClient;
 
@@ -24,37 +25,111 @@ public class TokenService {
     private TokenDataHolder tokenDataHolder;
 
     @Value("${client-id}")
-    String clientId;
+    private String clientId;
 
     @Value("${client-secret}")
-    String clientSecret;
+    private String clientSecret;
 
     @Value("${grant-type}")
-    String grantType;
+    private String grantType;
+
+    @Value("${user-name}")
+    private String userName;
+
+    @Value("${password}")
+    private String password;
+
+    @Value("${refresh-token}")
+    private String refreshToken;
+
+    @Value("${jwt-token}")
+    private String jwtToken;
+
+    @Value("${saml2-assertion}")
+    private String saml2Assertion;
 
     // Method to fetch the token and store it in TokenDataHolder
-    public String fetchToken(String scope) {
-        // Check if scope is null or empty
+    public Object fetchToken(String scope) {
+
+        if (clientId == null || clientId.isEmpty()) {
+            return createErrorResponse(400,
+                    "Missing client ID",
+                    "clientId is not configured.");
+        }
+
+        if (clientSecret == null || clientSecret.isEmpty()) {
+            return createErrorResponse(400,
+                    "Missing client secret",
+                    "clientSecret is not configured.");
+        }
+
+        if (grantType == null || grantType.isEmpty()) {
+            return createErrorResponse(400,
+                    "Missing grant type",
+                    "grantType is not configured.");
+        }
+
         if (scope == null || scope.isEmpty()) {
-            log.error("Scope is null or empty, cannot fetch token.");
-            return null;
+            return createErrorResponse(400,
+                    "Missing scope",
+                    "Scope is required to fetch the token.");
         }
 
-        // Create Authorization header (Basic auth)
         String auth = clientId + ":" + clientSecret;
         String encodedAuth = Base64.getEncoder().encodeToString(auth.getBytes(StandardCharsets.UTF_8));
-        String authHeader = "Basic " + encodedAuth;
-        String body = "grant_type=" + grantType + "&scope=" + scope + "&username = admin" + "&password = admin";
+        String authHeader;
+        String body;
+
+        switch (grantType) {
+
+            case "implicit":
+                return createErrorResponse(501,
+                        "Not Implemented",
+                        "Implicit grant type not handled directly.");
+
+            case "password":
+                authHeader = "Basic " + encodedAuth;
+                body = "grant_type=" + grantType+ "&username=" + userName + "&password=" + password + "&scope=" + scope;
+                break;
+
+            case "client_credentials":
+                authHeader = "Basic " + encodedAuth;
+                body = "grant_type=client_credentials&scope=" + scope;
+                break;
+
+            case "refresh_token":
+                authHeader = "Basic " + encodedAuth;
+                body = "grant_type=refresh_token&refresh_token=" + refreshToken;
+                break;
+
+            case "urn:ietf:params:oauth:grant-type:jwt-bearer":
+                authHeader = "Basic " + encodedAuth;
+                body = "grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&assertion=" + jwtToken;
+                break;
+
+            case "urn:ietf:params:oauth:grant-type:saml2-bearer":
+                authHeader = "Basic " + encodedAuth;
+                body = "grant_type=urn:ietf:params:oauth:grant-type:saml2-bearer&assertion=" + saml2Assertion;
+                break;
+
+            case "iwa-ntlm":
+                return createErrorResponse(501,
+                        "Not Implemented",
+                        "IWA-NTLM grant type not handled directly.");
+
+            default:
+                return createErrorResponse(400,
+                        "Invalid grant type",
+                        "Unsupported grant type: " + grantType);
+        }
 
-        // Declare the response map outside the try block
         Map<String, String> response;
 
         try {
             // Call FeignClient to generate the token
             response = authFeignClient.getToken(body, authHeader);
-            log.info("Request sent to oauth2 to get the token");
+            log.info("Request sent to OAuth2 server to get the token");
 
-            // Store the token in TokenDataHolder
             if (response != null) {
                 String accessToken = response.get("access_token");
                 if (accessToken != null) {
@@ -66,14 +141,26 @@ public class TokenService {
                     return accessToken;
                 } else {
                     log.error("Access token not found in response");
+                    return createErrorResponse(500,
+                            "Token Error",
+                            "Access token not found in the response.");
                 }
             }
         } catch (FeignException e) {
-            log.error("Error while fetching token: " + e.getMessage());
+            log.error("Error while fetching token:{}",e.getMessage());
+            return createErrorResponse(500,
+                    "Feign Client Error",
+                    e.getMessage());
         } catch (Exception e) {
-            log.error("An unexpected error occurred: " + e.getMessage());
+            log.error("An unexpected error occurred:{}",e.getMessage());
+            return createErrorResponse(500,
+                    "Unexpected Error",
+                    e.getMessage());
         }
-        return null;
+
+        return createErrorResponse(500,
+                "Unknown Error",
+                "Failed to fetch the token for unknown reasons.");
     }
 
 }

auth_token_generator/src/main/java/io/entgra/auth_token_getter/util/TokenDataHolder.java

@@ -1,11 +1,11 @@
 package io.entgra.auth_token_getter.util;
 
+import lombok.Data;
 import lombok.Getter;
 import lombok.Setter;
 import org.springframework.stereotype.Component;
 
-@Setter
-@Getter
+@Data
 @Component
 public class TokenDataHolder {
 

auth_token_generator/src/main/resources/application.properties

@@ -3,4 +3,9 @@ auth_token_generation_uri=https://mgt.sg.local/
 client-id=AtczeBBwunLMt7Ol4Xc7eNDEuXsa
 client-secret=DX8dGTmN7elF3zQsSfbH4yjVm08a
 grant-type=client_credentials
-
+#grant-type=password
+refresh-token=""
+jwt-token =""
+saml2-assertion=""
+user-name =admin
+password = admin