diff --git a/src/main/java/org/gcube/portal/oauth/OauthService.java b/src/main/java/org/gcube/portal/oauth/OauthService.java
index f7bf7ef..e2bc9de 100644
--- a/src/main/java/org/gcube/portal/oauth/OauthService.java
+++ b/src/main/java/org/gcube/portal/oauth/OauthService.java
@@ -39,7 +39,7 @@ public class OauthService {
 	private static final org.slf4j.Logger logger = LoggerFactory.getLogger(OauthService.class);
 
 	/**
-	 * This map contains couples <code, {qualifier-token, insert time}>
+	 * This map contains couples <code, {qualifier-token, insert time, scope, redirect uri, client id}>
 	 */
 	private Map<String, CacheBean> entries;
 
@@ -115,8 +115,25 @@ public class OauthService {
 			return Response.status(status).entity("{\"error\"=\"Trying to access push-authentication-code method via a token different than USER is not allowed\"").build();
 		}else{
 
-			logger.info("Saving entry defined by " + bean + " in cache, token is " + token.substring(0, 10));
-			entries.put(bean.getCode(), new CacheBean(token, ScopeProvider.instance.get(), bean.getRedirectUri(), bean.getClientId(), System.currentTimeMillis()));
+			// check parameters
+			String code = bean.getCode();
+			String clientId = bean.getClientId();
+			String redirectUri = bean.getRedirectUri();
+
+			if(code == null || code.isEmpty())
+				return Response.status(Status.BAD_REQUEST).
+						entity("{\"error\"=\"'code' cannot be null or missing\"").build();
+
+			if(clientId == null || clientId.isEmpty())
+				return Response.status(Status.BAD_REQUEST).
+						entity("{\"error\"=\"'client_id' cannot be null or missing\"").build();
+
+			if(redirectUri == null || redirectUri.isEmpty())
+				return Response.status(Status.BAD_REQUEST).
+						entity("{\"error\"=\"'redirect_uri' cannot be null or missing\"").build();
+
+			logger.info("Saving entry defined by " + bean + " in cache, token is " + token.substring(0, 10) + "***************");
+			entries.put(code, new CacheBean(token, ScopeProvider.instance.get(), redirectUri, clientId, System.currentTimeMillis()));
 			return Response.status(status).build();
 		}
 
diff --git a/src/main/java/org/gcube/portal/oauth/cache/CacheBean.java b/src/main/java/org/gcube/portal/oauth/cache/CacheBean.java
index 7c5cc72..a904be9 100644
--- a/src/main/java/org/gcube/portal/oauth/cache/CacheBean.java
+++ b/src/main/java/org/gcube/portal/oauth/cache/CacheBean.java
@@ -39,8 +39,6 @@ public class CacheBean {
 		this.scope = scope;
 	}
 
-
-
 	public String getToken() {
 		return token;
 	}
diff --git a/src/main/java/org/gcube/portal/oauth/cache/CacheCleaner.java b/src/main/java/org/gcube/portal/oauth/cache/CacheCleaner.java
index 7381c55..95e61fb 100644
--- a/src/main/java/org/gcube/portal/oauth/cache/CacheCleaner.java
+++ b/src/main/java/org/gcube/portal/oauth/cache/CacheCleaner.java
@@ -50,7 +50,7 @@ public class CacheCleaner extends Thread {
 					}
 				}
 
-				logger.info("Going to sleep . Number of removed entries is " + removedEntries + " [" + new Date() + "]");
+				logger.info("Going to sleep. Number of removed entries is " + removedEntries + " [" + new Date() + "]");
 
 			} catch (InterruptedException e) {
 				logger.warn("Exception was " + e.getMessage());
diff --git a/src/main/java/org/gcube/portal/oauth/input/PushCodeBean.java b/src/main/java/org/gcube/portal/oauth/input/PushCodeBean.java
index 15ed14f..519a640 100644
--- a/src/main/java/org/gcube/portal/oauth/input/PushCodeBean.java
+++ b/src/main/java/org/gcube/portal/oauth/input/PushCodeBean.java
@@ -1,7 +1,5 @@
 package org.gcube.portal.oauth.input;
 
-import javax.validation.constraints.NotNull;
-
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
@@ -11,17 +9,18 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 public class PushCodeBean {
 
 	@JsonProperty("code") 
-	@NotNull(message="code cannot be null")
 	private String code;
-	
+
 	@JsonProperty("redirect_uri") 
-	@NotNull(message="redirect_uri cannot be null")
 	private String redirectUri;
-	
+
 	@JsonProperty("client_id") 
-	@NotNull(message="client_id cannot be null")
 	private String clientId;
 
+	public PushCodeBean() {
+		super();
+	}
+
 	/**
 	 * @param code
 	 * @param redirectUri
@@ -41,7 +40,7 @@ public class PushCodeBean {
 	public void setCode(String code) {
 		this.code = code;
 	}
-	
+
 	public String getRedirectUri() {
 		return redirectUri;
 	}