DOTNETIDS.IDS.Detect C# (CSharp) Method

        private List<Filter> Detect(string key, string val)
        {
            if (_exclusions.Contains(key))
            {
                return null;
            }

            if (key == null)
            {
                key = string.Empty;
            }

            if (val == null)
            {
                val = string.Empty;
            }

            //Check if input match a-Z_- for which there is no exploit
            string pattern = "^(\\w+)$";

            if (System.Text.RegularExpressions.Regex.IsMatch(key, pattern) && System.Text.RegularExpressions.Regex.IsMatch(val, pattern))
            {
                //No need to detect further
                return null;
            }

            List<Filter> ret = new List<Filter>();

            //START DECODING

            /* Match PHPIDS' conversion order
            $value = IDS_Converter::convertFromUTF7($value);
            $value = IDS_Converter::convertQuotes($value);
            $value = IDS_Converter::convertFromJSCharcode($value);
            $value = IDS_Converter::convertFromCommented($value);
            $value = IDS_Converter::convertConcatenations($value);
            */

            string keydecoded = key;
            string valdecoded = val;

            //UTF7 Decode
            if (UTF7Decode)
            {
                keydecoded = CharsetConverter.convertFromUTF7(keydecoded);
                valdecoded = CharsetConverter.convertFromUTF7(valdecoded);
            }

            //Quotes Decode
            keydecoded += CharsetConverter.convertQuotes(keydecoded);
            valdecoded += CharsetConverter.convertQuotes(valdecoded);
            
            //JS Decode
            if (JSDecode)
            {
                keydecoded += CharsetConverter.convertFromJSCharcode(keydecoded);
                valdecoded += CharsetConverter.convertFromJSCharcode(valdecoded);
            }

            //Comment decode
            keydecoded += CharsetConverter.convertComments(keydecoded);
            valdecoded += CharsetConverter.convertComments(valdecoded);

            //Concat decode
            keydecoded += CharsetConverter.convertConcats(keydecoded);
            valdecoded += CharsetConverter.convertConcats(valdecoded);

            //Centrifuge decode
            //keydecoded += CharsetConverter.convertCentrifuge(keydecoded);
            //valdecoded += CharsetConverter.convertCentrifuge(valdecoded);

            foreach (Filter f in _store.FilterSet)
            {
                if (f.Match(valdecoded))
                {
                    ret.Add(f);
                }

                if (ScanKeys)
                {
                    if (f.Match(keydecoded))
                    {
                        ret.Add(f);
                    }
                }
            }

            return ret;
        }
        #endregion