Add method to get access token by providing refresh token in case of offline_access scope (2)

src/main/java/eu/dnetlib/authentication/configuration/AuthenticationConfiguration.java

@@ -1,10 +1,13 @@
 package eu.dnetlib.authentication.configuration;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
+import org.springframework.web.client.RestTemplate;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -39,4 +42,13 @@ public class AuthenticationConfiguration {
         map.put("authentication.authorities-mapper", properties.getAuthoritiesMapper());
         return map;
     }
+
+    @Bean
+    RestTemplate restTemplate() {
+        RestTemplate restTemplate = new RestTemplate();
+        MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
+        converter.setObjectMapper(new ObjectMapper());
+        restTemplate.getMessageConverters().add(converter);
+        return restTemplate;
+    }
 }

src/main/java/eu/dnetlib/authentication/controllers/UserController.java

@@ -1,12 +1,15 @@
 package eu.dnetlib.authentication.controllers;
 
+import eu.dnetlib.authentication.entities.TokenResponse;
 import eu.dnetlib.authentication.entities.User;
 import eu.dnetlib.authentication.configuration.Properties;
 import eu.dnetlib.authentication.services.UserInfoService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.ResponseEntity;
+import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import javax.servlet.http.HttpServletRequest;
@@ -31,6 +34,12 @@ public class UserController {
         return ResponseEntity.ok(userInfoService.getUserInfo());
     }
 
+    @RequestMapping(value = "/accessToken", method = RequestMethod.GET)
+    @PreAuthorize("@SecurityService.hasRefreshToken()")
+    public ResponseEntity<TokenResponse> getAccessToken(@RequestParam(name = "refreshToken") String refreshToken) {
+        return ResponseEntity.ok(this.userInfoService.getAccessToken(refreshToken));
+    }
+
     @RequestMapping(value = "/redirect",method = RequestMethod.GET)
     public void redirect(HttpServletRequest request, HttpServletResponse response) throws IOException {
         HttpSession session = request.getSession();

src/main/java/eu/dnetlib/authentication/entities/TokenResponse.java

@@ -1,2 +1,37 @@
-package eu.dnetlib.authentication.entities;public class TokenResponse {
+package eu.dnetlib.authentication.entities;
+
+public class TokenResponse {
+    String access_token;
+    Long expires_in;
+    String id_token;
+    String refresh_token;
+    String scope;
+    String token_type;
+
+    public TokenResponse() {
+    }
+
+    public String getAccess_token() {
+        return access_token;
+    }
+
+    public Long getExpires_in() {
+        return expires_in;
+    }
+
+    public String getId_token() {
+        return id_token;
+    }
+
+    public String getRefresh_token() {
+        return refresh_token;
+    }
+
+    public String getScope() {
+        return scope;
+    }
+
+    public String getToken_type() {
+        return token_type;
+    }
 }

src/main/java/eu/dnetlib/authentication/services/SecurityService.java

@@ -1,2 +1,22 @@
-package eu.dnetlib.authentication.services;public class SecurityService {
+package eu.dnetlib.authentication.services;
+
+import eu.dnetlib.authentication.utils.PropertyReader;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.Set;
+
+@Component(value = "SecurityService")
+public class SecurityService {
+
+    Set<String> scopes;
+
+    @Autowired
+    public SecurityService(PropertyReader reader) {
+        this.scopes = reader.getScopes();
+    }
+
+    public boolean hasRefreshToken() {
+        return this.scopes.contains("offline_access");
+    }
 }

src/main/java/eu/dnetlib/authentication/services/UserInfoService.java

@@ -1,20 +1,56 @@
 package eu.dnetlib.authentication.services;
 
+import eu.dnetlib.authentication.entities.TokenResponse;
 import eu.dnetlib.authentication.entities.User;
 import eu.dnetlib.authentication.exception.ResourceNotFoundException;
+import org.mitre.oauth2.model.RegisteredClient;
+import org.mitre.openid.connect.config.ServerConfiguration;
 import org.mitre.openid.connect.model.OIDCAuthenticationToken;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Service;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
 
 @Service
 public class UserInfoService {
 
+    RestTemplate restTemplate;
+    RegisteredClient client;
+    ServerConfiguration server;
+
+    public UserInfoService(RestTemplate restTemplate, RegisteredClient client, ServerConfiguration server) {
+        this.restTemplate = restTemplate;
+        this.client = client;
+        this.server = server;
+    }
+
     public User getUserInfo() throws ResourceNotFoundException {
         Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
-        if(authentication instanceof OIDCAuthenticationToken) {
+        if (authentication instanceof OIDCAuthenticationToken) {
             return new User((OIDCAuthenticationToken) authentication);
         }
         throw new ResourceNotFoundException("No Session has been found");
     }
+
+    public TokenResponse getAccessToken(String refreshToken) {
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+        HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<>(getTokenRequest(refreshToken), headers);
+        return restTemplate.postForObject(this.server.getTokenEndpointUri(), entity, TokenResponse.class);
+    }
+
+    public MultiValueMap<String, String> getTokenRequest(String refreshToken) {
+        MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("client_id", this.client.getClientId());
+        map.add("client_secret", this.client.getClientSecret());
+        map.add("grant_type", "refresh_token");
+        map.add("refresh_token", refreshToken);
+        map.add("scope", "openid");
+        return map;
+    }
 }