C#破解Access MDB 数据库加密的密码

支持Access97和Access2000密码的查看和破解！由于密码加密部分在文件头，所以不需要读取所有的文件即可快速计算出文件密码

关键字节：

Access2000 [0xbe, 0xec, 0x65, 0x9c, 0xfe,0x28, 0x2b, 0x8a, 0x6c, 0x7b,0xcd, 0xdf, 0x4f]

Access97 [0x86,0xfb,0xec,0x37,0x5d,0x44,0x9c,0xfa,0xc6,0x5e,0x28,0xe6,0x13]

快速读取Access MDB数据库加密的密码，不管你几个G的数据库，理论上也是秒读

/// <summary>
/// 获取Access数据库的密码
/// </summary>
/// <param name="file">文件路径</param>
/// <returns></returns>

public static string GetMdbPassword(string file)
{
    // 未加密的文件0x42开始至0x61之前的每间隔一字节的数值
    byte[] baseByte =
    {
        0xbe, 0xec, 0x65, 0x9c, 0xfe, 0x28, 0x2b, 0x8a, 0x6c, 0x7b, 0xcd, 0xdf, 0x4f, 0x13, 0xf7, 0xb1,
    };
    // 标志 0x62 处的数值
    const byte flagByte = 0x0c;
    var password = "";
    try
    {
        using (var fs = File.OpenRead(file))
        {
            fs.Seek(0x14, SeekOrigin.Begin);
            // 取得版本, 1为Access2000, 0为Access97
            var ver = (byte)fs.ReadByte();
            fs.Seek(0x42, SeekOrigin.Begin);
            var bs = new byte[33];
            if (fs.Read(bs, 0, 33) != 33) return "";
            var flag = (byte)(bs[32] ^ flagByte);
            for (int i = 0; i < 16; i++)
            {
                var b = (byte)(baseByte[i] ^ bs[i * 2]);
                if (i % 2 == 0 && ver == 1) b ^= flag; //Access 2000
                if (b <= 0) continue;
                var ch = (char)b;
                password += ch;
            }
        }
    }
    catch
    {
    }

    return password;
}