/// <summary>
/// 解密
/// </summary>
/// <param name="packageInfo">消息包</param>
/// <param name="buffer">数据</param>
/// <param name="structure">结构</param>
/// <param name="offset">偏移量</param>
/// <returns></returns>
public override void Decrypt(IJTTPackageInfo packageInfo, ReadOnlySpan <byte> buffer, StructureInfo structure, int offset)
{
try
{
if (protocol.Encrypt.Targets?.ContainsKey(structure.Id) != true)
{
return;
}
var encryptProperty = protocol.Encrypt.Targets[structure.Id];
var flag = (bool)packageInfo.GetPropertyValue(encryptProperty.Flag.Split('.'));
if (!flag)
{
return;
}
var length = buffer.Length - offset - protocol.Structures.Where(o => o.Order > structure.Order).Sum(o => o.Length.Value);
var key = (UInt32)packageInfo.GetPropertyValue(encryptProperty.Key.Split('.'));
using MemoryStream ms_encrypt = new MemoryStream();
var writer = new BinaryWriter(ms_encrypt);
using (MemoryStream ms = new MemoryStream(buffer.ToArray()))
{
var reader = new BinaryReader(ms);
//获取加密的数据
ms.Seek(offset, SeekOrigin.Begin);
//解密
while (ms.Position < length)
{
var Char = reader.ReadChar();
//将传输的数据与伪随机码按字节进行异或运算
key = protocol.Encrypt.IA1 * (key % protocol.Encrypt.M1) + protocol.Encrypt.IC1;
Char ^= (Char)((key << 20) & 0xff);
//写入解密的数据
writer.Write(Char);
}
}
buffer = ms_encrypt.ToArray();
}
catch (Exception ex)
{
throw new JTTException($"解密时发生错误, structureId: {structure.Id}.", ex);
}
}
public override void Encrypt(IJTTPackageInfo packageInfo, byte[] buffer, StructureInfo structure)
{
try
{
if (protocol.Encrypt.Targets?.ContainsKey(structure.Id) != true)
{
return;
}
var encryptProperty = protocol.Encrypt.Targets[structure.Id];
if (!(bool)packageInfo.GetPropertyValue(encryptProperty.Flag.Split('.')))
{
return;
}
//生成Key
var key_bytes = new byte[4];
new Random().NextBytes(key_bytes);
var key = BitConverter.ToUInt32(key_bytes);
//写入Key
packageInfo.SetValueToProperty(encryptProperty.Key.Split('.'), key);
using MemoryStream ms_encrypt = new MemoryStream();
var writer = new BinaryWriter(ms_encrypt);
using (MemoryStream ms = new MemoryStream(buffer))
{
var reader = new BinaryReader(ms);
while (ms.Position < ms.Length)
{
var @char = reader.ReadChar();
//将待传输的数据与伪随机码按字节进行异或运算
key = protocol.Encrypt.IA1 * (key % protocol.Encrypt.M1) + protocol.Encrypt.IC1;
@char ^= (Char)((key >> 20) & 0xff);
//写入加密的数据
writer.Write(@char);
}
}
buffer = ms_encrypt.ToArray();
}
catch (Exception ex)
{
throw new JTTException($"加密时发生错误, structureId: {structure.Id}.", ex);
}
}