Packet CommadnLogin3

[Necessary 0]

Hey hey,

I want to send packets to a server.

The basic struct of the CommandLogin3 is the following(in my knowledge):

 

1 byte Header

31 byte loginname

17 byte password

16 byte encryption key 

Result = 65 Bytes

Now the problem: The server I want to connect expects 66 bytes and not 65 bytes.

anyone knows the structure of the login paket? 

[ds_aim 263]

1 hour ago, Necessary said:

Hey hey,

I want to send packets to a server.

The basic struct of the CommandLogin3 is the following(in my knowledge):

 

1 byte Header

31 byte loginname

17 byte password

16 byte encryption key 

Result = 65 Bytes

Now the problem: The server I want to connect expects 66 bytes and not 65 bytes.

anyone knows the structure of the login paket? 

#pragma pack instructs the compiler to pack structure members with particular alignment. Most compilers, when you declare a struct, will insert padding between members to ensure that they are aligned to appropriate addresses in memory (usually a multiple of the type's size). This avoids the performance penalty (or outright error) on some architectures associated with accessing variables that are not aligned properly. For example, given 4-byte integers and the following struct:

struct Test
{
   char AA;
   int BB;
   char CC;
};

The compiler could choose to lay the struct out in memory like this:

|   1   |   2   |   3   |   4   |  

| AA(1) | pad.................. |
| BB(1) | BB(2) | BB(3) | BB(4) | 
| CC(1) | pad.................. |

and sizeof(Test) would be 4 × 3 = 12, even though it only contains 6 bytes of data. The most common use case for the #pragma (to my knowledge) is when working with hardware devices where you need to ensure that the compiler does not insert padding into the data and each member follows the previous one. With #pragma pack(1), the struct above would be laid out like this:

|   1   |

| AA(1) |
| BB(1) |
| BB(2) |
| BB(3) |
| BB(4) |
| CC(1) |

And sizeof(Test) would be 1 × 6 = 6.

With #pragma pack(2), the struct above would be laid out like this:

|   1   |   2   | 

| AA(1) | pad.. |
| BB(1) | BB(2) |
| BB(3) | BB(4) |
| CC(1) | pad.. |

And sizeof(Test) would be 2 × 4 = 8.

 

 

 

Use pragma pack

[Necessary 0]

First of all thanks for your answer. Im programming in c# so i use   [StructLayout(LayoutKind.Sequential, Pack = 1)] and it works.

Handshake paket works, Keyagreement, keyagreement_completed works too. But the login paket (CommandLogin3) only sends 65 bytes.

If i login with original metin2client and sniff the pakets it sends 66 bytes, my program only sends 65 ..

maybe they changed the structure?