using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace Masuit.Tools.Security;
///
/// 零宽字符串编解码器
///
public static class ZeroWidthCodec
{
///
/// 注入零宽字符串
///
///
///
///
public static string InjectZeroWidthString(this string s, string hidden)
{
return Encrypt(s, hidden);
}
///
/// 编码为零宽字符串
///
///
///
public static string EncodeToZeroWidthText(this string s)
{
return Encode(s);
}
///
/// 解码零宽字符串
///
///
///
public static string DecodeZeroWidthString(this string s)
{
return Decrypt(s);
}
///
/// 注入零宽字符串
///
/// 显示字符串
/// 隐式字符串
///
public static string Encrypt(string pub, string hidden)
{
// 将字符串拆分成单个字符
var pubMsg = pub.ToCharArray();
var hiddenMsg = Str2Bin(Encoding.UTF8.GetBytes(hidden));// 将需要隐藏的字符串转换成二进制格式
hiddenMsg = Bin2Hidden(hiddenMsg);// 将二进制转换成隐藏字符格式
hiddenMsg = $"\uFEFF{hiddenMsg}\uFEFF";// 用边界字符包装隐藏的字符
if (pubMsg.Length == 1)
{
return pub + hiddenMsg;
}
// 将编码的隐藏消息注入到公共字符串的大约中间位置
int half = pub.Length / 2;
var chars = new List();
for (var i = 0; i < pubMsg.Length; i++)
{
if (i == half)
{
chars.AddRange(hiddenMsg);
}
chars.Add(pubMsg[i]);
}
return string.Concat(chars);
}
///
/// 编码为零宽字符串
///
///
///
public static string Encode(string str)
{
var encodeText = new StringBuilder(string.Join(" ", Encoding.UTF8.GetBytes(str).Select(byt => Convert.ToString(byt, 2).PadLeft(8, '0'))))
.Replace('\u0030', '\u200B')
.Replace('\u0031', '\u200C')
.Replace('\u0020', '\u200D')
.ToString();
return encodeText;
}
///
/// 解码零宽字符串
///
///
///
public static string Decrypt(string pub)
{
var unwrapped = Unwrap(pub);
var message = Bin2Str(unwrapped == "false" ? Hidden2Bin(pub) : Hidden2Bin(unwrapped));
return message.Length < 2 ? "No private message was found in that text." : message;
}
private static string Str2Bin(byte[] text)
{
return string.Join(" ", text.Select(byt => Convert.ToString(byt, 2).PadLeft(8, '0')));
}
private static string Unwrap(string text)
{
var tmp = text.Split("\uFEFF".ToCharArray());
return tmp.Length == 1 ? "false" : tmp[1];
}
private static string Bin2Str(string bin)
{
bin = Regex.Replace(bin, "[^0-1]", " ");
return Encoding.UTF8.GetString(Enumerable.Range(0, bin.Split().Length).Select(vw => Convert.ToByte(Regex.Replace(bin.Split()[vw], @"\s", ""), 2)).ToArray());
}
private static string Bin2Hidden(string text)
{
text = text.Replace(" ", "\u2060"); // Unicode Character 'WORD JOINER' (U+2060) 0xE2 0x81 0xA0
text = text.Replace("0", "\u200B"); // Unicode Character 'ZERO WIDTH SPACE' (U+200B) 0xE2 0x80 0x8B
text = text.Replace("1", "\u200C"); // Unicode Character 'ZERO WIDTH NON-JOINER' (U+200C) 0xE2 0x80 0x8C
return text;
}
private static string Hidden2Bin(string text)
{
text = text.Replace("\u2060", " "); // Unicode Character 'WORD JOINER' (U+2060) 0xE2 0x81 0xA0
text = text.Replace("\u200B", "0"); // Unicode Character 'ZERO WIDTH SPACE' (U+200B) 0xE2 0x80 0x8B
text = text.Replace("\u200C", "1"); // Unicode Character 'ZERO WIDTH NON-JOINER' (U+200C) 0xE2 0x80 0x8C
return text;
}
}