Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(révision 111858)
+++ channels/chan_sip.c	(copie de travail)
@@ -11551,6 +11551,7 @@
 	const char *secret;
 	const char *md5secret;
 	struct sip_auth *auth = NULL;	/* Realm authentication */
+	struct sip_user *user = NULL;   /* User credential propagation */
 
 	if (!ast_strlen_zero(p->domain))
 		ast_copy_string(uri, p->domain, sizeof(uri));
@@ -11570,14 +11571,21 @@
  		md5secret = auth->md5secret;
 		if (sipdebug)
  			ast_log(LOG_DEBUG,"Using realm %s authentication for call %s\n", p->realm, p->callid);
- 	} else {
- 		/* No authentication, use peer or register= config */
- 		username = p->authname;
- 		secret =  p->peersecret;
- 		md5secret = p->peermd5secret;
- 	}
-	if (ast_strlen_zero(username))	/* We have no authentication */
-		return -1;
+	} else {
+		/* IVeS: propagate USER credentials to the remote proxy */
+		user = find_user(p->fromuser, 1);
+		if ( user ) {
+			username = user->name;
+			secret = user->secret;
+			md5secret = user->md5secret;
+			ast_log(LOG_DEBUG,"proxy auth: propagating credentials of user %s to external proxy\n", p->realm, p->callid);
+		} else {
+			/* no auth. fail */
+			ast_log(LOG_WARNING, "proxy auth: no auth available for call %s\n",
+			p->callid);
+			return -1;
+		}
+	}
 
  	/* Calculate SIP digest response */
  	snprintf(a1,sizeof(a1),"%s:%s:%s", username, p->realm, secret);