Digest Authentication in Webserver Library (#3053)

* Add Digest Auth

* Check for Opaque and Nonce

* Remove Serial Debug and fix Indentation

* Added example sketch with documentation,Fixed indentation and Defaults

* Digest Authentication minor changes + new padded 32 digit random function

* update license to public domain

* renaming functions

libraries/ESP8266WebServer/src/ESP8266WebServer.h

@@ -31,6 +31,7 @@ enum HTTPMethod { HTTP_ANY, HTTP_GET, HTTP_POST, HTTP_PUT, HTTP_PATCH, HTTP_DELE
 enum HTTPUploadStatus { UPLOAD_FILE_START, UPLOAD_FILE_WRITE, UPLOAD_FILE_END,
                         UPLOAD_FILE_ABORTED };
 enum HTTPClientStatus { HC_NONE, HC_WAIT_READ, HC_WAIT_CLOSE };
+enum HTTPAuthMethod { BASIC_AUTH, DIGEST_AUTH };
 
 #define HTTP_DOWNLOAD_UNIT_SIZE 1460
 
@@ -78,7 +79,7 @@ public:
   void stop();
 
   bool authenticate(const char * username, const char * password);
-  void requestAuthentication();
+  void requestAuthentication(HTTPAuthMethod mode = BASIC_AUTH, const char* realm = NULL, const String& authFailMsg = String("") );
 
   typedef std::function<void(void)> THandlerFunction;
   void on(const String &uri, THandlerFunction handler);
@@ -149,6 +150,10 @@ protected:
   uint8_t _uploadReadByte(WiFiClient& client);
   void _prepareHeader(String& response, int code, const char* content_type, size_t contentLength);
   bool _collectHeader(const char* headerName, const char* headerValue);
+  
+  String _getRandomHexString();
+  // for extracting Auth parameters
+  String _exractParam(String& authReq,const String& param,const char delimit = '"');
 
   struct RequestArgument {
     String key;
@@ -182,6 +187,10 @@ protected:
   String           _hostHeader;
   bool             _chunked;
 
+  String           _snonce;  // Store noance and opaque for future comparison
+  String           _sopaque;
+  String           _srealm;  // Store the Auth realm between Calls
+
 };