don't check TRANSIENT destination

libi2pd_client/SAM.cpp

@@ -367,13 +367,16 @@ namespace client
 			return;
 		}
 
-		//ensure it's a base64 string
-		i2p::data::PrivateKeys keys;
-		if (!keys.FromBase64(destination))
-		{
-			SendMessageReply(SAM_SESSION_STATUS_INVALID_KEY, strlen(SAM_SESSION_STATUS_INVALID_KEY), true);
-			return;
-		}
+		if (destination != SAM_VALUE_TRANSIENT)
+		{	
+			//ensure it's a base64 string
+			i2p::data::PrivateKeys keys;
+			if (!keys.FromBase64(destination))
+			{
+				SendMessageReply(SAM_SESSION_STATUS_INVALID_KEY, strlen(SAM_SESSION_STATUS_INVALID_KEY), true);
+				return;
+			}
+		}		
 
 		// create destination
 		auto session = m_Owner.CreateSession (id, destination == SAM_VALUE_TRANSIENT ? "" : destination, &params);