Inner configuration/credential management virtualized to reduce cluttering code

lib/TTLS/include/Credentials.h

@@ -29,10 +29,8 @@ namespace eap
 #pragma once
 
 #include "../../TLS/include/Credentials.h"
-#include "../../PAP/include/Credentials.h"
 
 #include <memory>
-#include <utility>
 
 
 namespace eap
@@ -180,18 +178,19 @@ namespace eap
         /// 2. Pre-configured credentials
         /// 3. Stored credentials
         ///
-        /// \param[in] cred_cached    Cached credentials (optional, can be \c NULL)
-        /// \param[in] cfg            Method configuration
+        /// \param[in] cred_cached    Cached credentials (optional, can be \c NULL, must be credentials_ttls* type)
+        /// \param[in] cfg            Method configuration (must be config_method_ttls type)
         /// \param[in] pszTargetName  The name in Windows Credential Manager to retrieve credentials from (optional, can be \c NULL)
         ///
         /// \returns
-        /// - \c true  if credentials were set;
-        /// - \c false otherwise
+        /// - \c source_cache      Credentials were obtained from EapHost cache
+        /// - \c source_preshared  Credentials were set by method configuration
+        /// - \c source_storage    Credentials were loaded from Windows Credential Manager
         ///
-        std::pair<source_t, source_t> combine(
-            _In_       const credentials_ttls   *cred_cached,
-            _In_       const config_method_ttls &cfg,
-            _In_opt_z_       LPCTSTR            pszTargetName);
+        virtual source_t combine(
+            _In_       const credentials             *cred_cached,
+            _In_       const config_method_with_cred &cfg,
+            _In_opt_z_       LPCTSTR                 pszTargetName);
 
     public:
         std::unique_ptr<credentials> m_inner;   ///< Inner credentials