js加密+c#後臺解密

 <script>
  var result = getEncodeString( "123xx");
 alert（result ）；
        var getEncodeString = function (srcString) {
            var BASE32CHAR = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
            var i = 0;
            var index = 0;
            var digit = 0;
            var currByte;
            var nextByte;
            var retrunString = '';

            for (var i = 0; i < srcString.length;) {
                //var          index    = 0;   
                currByte = (srcString.charCodeAt(i) >= 0) ? srcString.charCodeAt(i)
                                        : (srcString.charCodeAt(i) + 256);

                if (index > 3) {
                    if ((i + 1) < srcString.length) {
                        nextByte = (srcString.charCodeAt(i + 1) >= 0)
                                                    ? srcString.charCodeAt(i + 1)
                                                    : (srcString.charCodeAt(i + 1) + 256);
                    } else {
                        nextByte = 0;
                    }

                    digit = currByte & (0xFF >> index);
                    index = (index + 5) % 8;
                    digit <<= index;
                    digit |= (nextByte >> (8 - index));
                    i++;
                } else {
                    digit = (currByte >> (8 - (index + 5))) & 0x1F;
                    index = (index + 5) % 8;

                    if (index == 0) {
                        i++;
                    }
                }

                retrunString = retrunString + BASE32CHAR.charAt(digit);
            }
            return retrunString.toLowerCase();
        }

    </script>

        /// <summary>
        /// BASE32解碼
        /// </summary>
        /// <param name="encodeString"></param>
        /// <returns></returns>
        private string getDecodeString(string encodeString)
        {
            int i;
            int index;
            int lookup;
            int offset;
            int digit;
            string en_string = encodeString.ToUpper();
            int[] BASE32LOOOKUP = new int[]{
               0xFF, 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, // '0', '1', '2', '3', '4', '5', '6', '7'
               0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // '8', '9', ':', ';', '<', '=', '>', '?'
               0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, // '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G'
               0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, // 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O'
               0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, // 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W'
               0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 'X', 'Y', 'Z', '[', '\', ']', '^', '_'
               0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, // '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g'
               0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, // 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o'
               0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, // 'p', 'q', 'r', 's', 't', 'u', 'v', 'w'
               0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF,0xFF
               };
            int stringLen = ((en_string.Length * 5) / 8);
            int[] bytes = new int[stringLen];
            for (var a = 0; a < stringLen; a++)
            {
                bytes[a] = 0;
            }

            for (i = 0, index = 0, offset = 0; i < en_string.Length; i++)
            {
                var charCode0 = (short)'0';
                lookup = (short)en_string[i] - charCode0;

                if ((lookup < 0) || (lookup >= BASE32LOOOKUP.Length))
                {
                    continue;
                }

                digit = BASE32LOOOKUP[lookup];

                if (digit == 0xFF)
                {
                    continue;
                }

                if (index <= 3)
                {
                    index = (index + 5) % 8;

                    if (index == 0)
                    {
                        bytes[offset] = bytes[offset] | digit;

                        offset++;

                        if (offset >= bytes.Length)
                        {
                            break;
                        }
                    }
                    else
                    {
                        bytes[offset] = bytes[offset] | (digit << (8 - index));

                    }
                }
                else
                {
                    index = (index + 5) % 8;
                    bytes[offset] = bytes[offset] | (digit >> index);

                    offset++;

                    if (offset >= bytes.Length)
                    {
                        break;
                    }

                    bytes[offset] = bytes[offset] | (digit << (8 - index));
                    if (bytes[offset] >= 256)
                    {
                        bytes[offset] %= 256;
                    }
                }
            }
            string realkeyString = "";
            for (var a = 0; a < bytes.Length; a++)
            {

                var realkey = (char)bytes[a];
                realkeyString += realkey;
            }
            return realkeyString;
        }