diff --git a/extensions/app_sip/userauthorization.c b/extensions/app_sip/userauthorization.c
new file mode 100644
index 0000000..f87ceb6
--- /dev/null
+++ b/extensions/app_sip/userauthorization.c
@@ -0,0 +1,337 @@
+/*********************************************************************************************************
+* Software License Agreement (BSD License)                                                               *
+* Author: Alexandre Westfahl <awestfahl@freediameter.net>						 *
+*													 *
+* Copyright (c) 2010, Alexandre Westfahl, Teraoka Laboratory (Keio University), and the WIDE Project. 	 *		
+*													 *
+* All rights reserved.											 *
+* 													 *
+* Redistribution and use of this software in source and binary forms, with or without modification, are  *
+* permitted provided that the following conditions are met:						 *
+* 													 *
+* * Redistributions of source code must retain the above 						 *
+*   copyright notice, this list of conditions and the 							 *
+*   following disclaimer.										 *
+*    													 *
+* * Redistributions in binary form must reproduce the above 						 *
+*   copyright notice, this list of conditions and the 							 *
+*   following disclaimer in the documentation and/or other						 *
+*   materials provided with the distribution.								 *
+* 													 *
+* * Neither the name of the Teraoka Laboratory nor the 							 *
+*   names of its contributors may be used to endorse or 						 *
+*   promote products derived from this software without 						 *
+*   specific prior written permission of Teraoka Laboratory 						 *
+*   													 *
+* 													 *
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED *
+* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *
+* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR *
+* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 	 *
+* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 	 *
+* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR *
+* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF   *
+* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.								 *
+*********************************************************************************************************/
+#include "app_sip.h"
+
+
+int app_sip_UAR_cb( struct msg ** msg, struct avp * paramavp, struct session * sess, void * opaque, enum disp_action * act)
+{
+	TRACE_ENTRY("%p %p %p %p", msg, paramavp, sess, act);
+	
+	struct msg *ans, *qry;
+	struct avp *avp, *groupedavp=NULL;
+	struct avp_hdr *avphdr, *sipaorhdr, *visitednethdr, *usernamehdr;
+	union avp_value value;
+	int ret=0, hascap=0;
+	
+	//Result_Code to return in the answer
+	char result[55];
+	
+	if (msg == NULL)
+		return EINVAL;
+
+	
+	// Create answer header 
+	qry = *msg;
+	CHECK_FCT( fd_msg_new_answer_from_req ( fd_g_config->cnf_dict, msg, 0 ) );
+	ans = *msg;
+	
+	//Add the Auth-Application-Id 
+	{
+		CHECK_FCT( fd_msg_avp_new ( sip_dict.Auth_Application_Id, 0, &avp ) );
+		value.i32 = 6;
+		CHECK_FCT( fd_msg_avp_setvalue ( avp, &value ) );
+		CHECK_FCT( fd_msg_avp_add ( ans, MSG_BRW_LAST_CHILD, avp) );
+	}
+	// Add the Auth-Session-State AVP 
+	{
+		
+		CHECK_FCT( fd_msg_search_avp ( qry, sip_dict.Auth_Session_State, &avp) );
+		CHECK_FCT( fd_msg_avp_hdr( avp, &avphdr )  );
+		
+		CHECK_FCT( fd_msg_avp_new ( sip_dict.Auth_Session_State, 0, &avp ) );
+		CHECK_FCT( fd_msg_avp_setvalue( avp, avphdr->avp_value ) );
+		CHECK_FCT( fd_msg_avp_add( ans, MSG_BRW_LAST_CHILD, avp ) );
+	}
+	
+	//Retrieve SIP-AOR
+	{
+		CHECK_FCT( fd_msg_search_avp ( qry, sip_dict.SIP_AOR, &avp) );
+		CHECK_FCT( fd_msg_avp_hdr( avp, &sipaorhdr )  );
+	}
+	
+	//We check if we have a User-Name AVP
+	{
+		CHECK_FCT( fd_msg_search_avp ( qry, sip_dict.User_Name, &avp) );
+		if(avp!=NULL)
+		{
+			CHECK_FCT( fd_msg_avp_hdr( avp, &usernamehdr )  );
+			
+			ret=get_password(usernamehdr->avp_value->os.data, usernamehdr->avp_value->os.len, NULL);
+			
+			
+			if(ret==1)
+			{//not found
+				strcpy(result,"DIAMETER_ERROR_USER_UNKNOWN");
+				goto out;
+			}
+			else if(ret==2)
+			{//error
+				//We couldn't make the request, we must stop process!
+				strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+				goto out;
+			}
+			else if(ret==0)
+			{//found
+				
+				//We must check that this user can use this SIP-AOR
+				ret=check_sipaor(usernamehdr->avp_value->os.data, usernamehdr->avp_value->os.len, (const char *)sipaorhdr->avp_value->os.data,sipaorhdr->avp_value->os.len);
+				
+				if(ret==0)
+				{
+					//The SIP-AOR and Username are ok!
+				}
+				else if(ret==1)
+				{//not found
+					strcpy(result,"DIAMETER_ERROR_IDENTITIES_DONT_MATCH");
+					goto out;
+				}
+				else
+				{//error
+					//We couldn't make the request, we must stop process!
+					strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+					goto out;
+				}
+			}
+		}
+	}
+	
+	//We check if we have a SIP-Visited-Network-Id AVP
+	{
+		CHECK_FCT( fd_msg_search_avp ( qry, sip_dict.SIP_Visited_Network_Id, &avp) );
+		
+		if(avp!=NULL)
+		{
+			CHECK_FCT( fd_msg_avp_hdr( avp, &visitednethdr )  );
+		}
+		else
+			visitednethdr=NULL;
+	}
+	
+	//We check if we have a SIP_User_Authorization_Type
+	{
+		int auth_type;
+		
+		CHECK_FCT( fd_msg_search_avp ( qry, sip_dict.SIP_User_Authorization_Type, &avp) );
+		
+		if(avp!=NULL)
+		{
+			CHECK_FCT( fd_msg_avp_hdr( avp, &avphdr )  );
+			auth_type=avphdr->avp_value->i32;
+			
+			if(auth_type==0 || auth_type==2)
+			{
+				if(visitednethdr!=NULL)
+				{
+					/*
+					If there is a SIP-Visited-Network-Id AVP in the Diameter UAR message,
+					and the SIP-User-Authorization-Type AVP value received in the
+					Diameter UAR message is set to REGISTRATION or REGISTRATION&
+					CAPABILITIES, then the Diameter server SHOULD verify whether the user
+					is allowed to roam into the network specified in the
+					SIP-Visited-Network-Id AVP in the Diameter UAR message.  If the user
+					is not allowed to roam into that network, the Diameter AAA server
+					MUST set the Result-Code AVP value in the Diameter UAA message to
+					DIAMETER_ERROR_ROAMING_NOT_ALLOWED.
+					*/
+					ret=allow_roaming(usernamehdr->avp_value->os.data, usernamehdr->avp_value->os.len, (const char *)visitednethdr->avp_value->os.data,visitednethdr->avp_value->os.len);
+					
+					if(ret==0)
+					{
+						//This user can come in this network
+					}
+					else if(ret==1)
+					{
+						strcpy(result,"DIAMETER_ERROR_ROAMING_NOT_ALLOWED");
+						goto out;
+					}
+					else
+					{
+						strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+						goto out;
+					}
+					
+				}
+				/*
+				If the SIP-User-Authorization-Type AVP value received in the Diameter
+				UAR message is set to REGISTRATION or REGISTRATION&CAPABILITIES, then
+				the Diameter server SHOULD verify whether the SIP-AOR AVP value is
+				authorized to register in the Home Realm.  Where the SIP AOR is not
+				authorized to register in the Home Realm, the Diameter server MUST
+				set the Result-Code AVP to DIAMETER_AUTHORIZATION_REJECTED and send
+				it in a Diameter UAA message.
+				*/
+				ret=exist_username(sipaorhdr->avp_value->os.data, sipaorhdr->avp_value->os.len);
+				if(ret==0)
+				{
+					//The SIP_AOR exists in this realm
+				}
+				else if(ret==1)
+				{
+					strcpy(result,"DIAMETER_AUTHORIZATION_REJECTED");
+					goto out;
+				}
+				else
+				{
+					strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+					goto out;
+				}
+			}
+		}
+		else
+			auth_type=0; //Registration only (default value if absent)
+		
+		
+		//Let's look for the SIP_Server_URI'
+		unsigned char *sipserver_uri;
+		size_t sipserverurilen;
+		
+		ret=get_sipserver_uri(sipaorhdr->avp_value->os.data, sipaorhdr->avp_value->os.len, &sipserver_uri, &sipserverurilen);
+		
+		if(ret==0)
+		{//We know a SIP Server so we must provide it
+			//We only add this AVP when we have registration or deregistration
+			if(auth_type==0 ||auth_type==1)
+			{
+				CHECK_FCT( fd_msg_avp_new ( sip_dict.SIP_Server_URI, 0, &avp ) );
+				value.os.data=sipserver_uri;
+				value.os.len=sipserverurilen;
+				CHECK_FCT( fd_msg_avp_setvalue( avp, &value ) );
+				CHECK_FCT( fd_msg_avp_add( ans, MSG_BRW_LAST_CHILD, avp ) );
+			}
+		}
+		else if(ret==1)
+		{
+			sipserver_uri=NULL;
+			sipserverurilen=0;
+			
+		}
+		else
+		{
+			strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+			goto out;
+		}
+		
+		//If we have a REGISTRATION or REGISTRATION & CAPABILITIES
+		if(auth_type==0 ||auth_type==2)
+		{
+			//Adding SIP-Server-Capabilities
+			CHECK_FCT( fd_msg_avp_new ( sip_dict.SIP_Server_Capabilities, 0, &groupedavp ) );
+			
+			ret=get_sipserver_cap(sipaorhdr->avp_value->os.data, sipaorhdr->avp_value->os.len,&groupedavp);
+			
+			if(ret==0)
+			{
+				CHECK_FCT( fd_msg_avp_add ( ans, MSG_BRW_LAST_CHILD, groupedavp) );
+				hascap=1;
+			}
+			else if(ret==1)
+			{
+				
+				hascap=0;
+			}
+			else
+			{
+				CHECK_FCT( fd_msg_free( groupedavp ) );
+				strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+				goto out;
+			}
+		}
+		
+		
+		
+		if(auth_type==0)
+		{//Registration
+			
+			if(sipserver_uri==NULL)
+			{
+				strcpy(result,"DIAMETER_FIRST_REGISTRATION");
+			}
+			else
+			{
+				if(hascap==1)
+				{
+					strcpy(result,"DIAMETER_SERVER_SELECTION");
+				}
+				else
+				{
+					//We free the Capabilities AVP because we didn't found any'
+					if(groupedavp!=NULL)
+						CHECK_FCT( fd_msg_free( groupedavp ) );
+					strcpy(result,"DIAMETER_SUBSEQUENT_REGISTRATION");
+				}
+			}
+		}
+		else if(auth_type==2)
+		{//Registration & Capabilities
+			//We let the groupedavp in the message even if there is no capabilities
+			
+			if(hascap==0)
+			{
+				CHECK_FCT( fd_msg_avp_add ( ans, MSG_BRW_LAST_CHILD, groupedavp) );
+			}
+			strcpy(result,"DIAMETER_SUCCESS");	
+		}
+		else if(auth_type==1)
+		{//Deregistration
+			if(sipserver_uri==NULL)
+			{
+				strcpy(result,"DIAMETER_ERROR_IDENTITY_NOT_REGISTERED");
+			}
+			else
+			{
+				strcpy(result,"DIAMETER_SUCCESS");	
+			}
+		}
+		else
+		{//We should never be here!!
+			strcpy(result,"DIAMETER_UNABLE_TO_COMPLY");
+			goto out;
+		}
+	}
+	
+	
+out:
+	CHECK_FCT( fd_msg_rescode_set( ans, result, NULL, NULL, 1 ) );
+	
+	
+	//fd_msg_dump_walk(INFO,ans);
+	
+	CHECK_FCT( fd_msg_send( msg, NULL, NULL ));
+	
+	
+	
+	return 0;
+}