does anybody knows how to generate the server seed?

[elfalcon]

header.please help me ... my emulator recieves the clientseed and then what..how should i generate the serverseed? i have the whole communication sniffed in wireshark but i cant just copypaste it cause its dynamic right? please help im sure someone of you know this

[WOST]

Ah, if you're going to developing gw2 emulator and you've already stuck here, I don't know how you're going to do it...

1) After generating of the shared key, the server generates a random seed and xors it with the shared key;
2) The server sends SS (= serverseed) to the client;
3) Both the client and the server hashes this SS with a hash custom function;
4) Using rc4 for cryptography... etc

If you've more questions, then ask me here.
P.S. Sorry for d-posting.

[WOST]

Ah, if you're going to developing gw2 emulator and you've already stuck here, I don't know how you're going to do it...

1) After generating of the shared key, the server generates a random seed and xors it with the shared key;
2) The server sends SS (= serverseed) to the client;
3) Both the client and the server hashes this SS with a hash custom function;
4) Using rc4 for cryptography... etc

If you've more questions, then ask me here.

[elfalcon]

Ah, if you're going to developing gw2 emulator and you've already stuck here, I don't know how you're going to do it...

1) After generating of the shared key, the server generates a random seed and xors it with the shared key;
2) The server sends SS (= serverseed) to the client;
3) Both the client and the server hashes this SS with a hash custom function;
4) Using rc4 for cryptography... etc

If you've more questions, then ask me here.

thanks for the reply ...i started to think that this thread is dead... so the serverseed is the shareedkey xored with a random value? it must be something specific? or anything 20byte long will do? i mean... will the client reply?..cause i dont know how to get the shared key.. im developing it with my friend and hes the reverse engineer but he is low on time :/

[WOST]

Gw2 client use RC4 encryption and Diffie-Hellman key exchange. So, I tell you about this crypto system.

1) At the server side:
a_server - (random) server private key;
g ^ (a_server) mod prime - server public key;

2) At the client side (the moment of exchange):
private - client private key;
public ^ private mod prime - shared key(Diffie-Hellman);
y_client (g ^ private mod prime) - client public key;

3) Client send y_client to the server;

4) At the server side (the moment of exchange):
y_client^x_server mod prime - shared key(Diffie-Hellman).

The size of public, prime and private key is 64 byte(512bit).
Prime is the constant of this schema, public key is static and private key is generating at process run.

There you go.

[WOST]

It's hard to understand you. Please, write correctly.

[Analhammer]

Gw2 client use RC4 encryption and Diffie-Hellman key exchange. So, I tell you about this crypto system.

1) At the server side:
a_server - (random) server private key;
g ^ (a_server) mod prime - server public key;

2) At the client side (the moment of exchange):
private - client private key;
public ^ private mod prime - shared key(Diffie-Hellman);
y_client (g ^ private mod prime) - client public key;

3) Client send y_client to the server;

4) At the server side (the moment of exchange):
y_client^x_server mod prime - shared key(Diffie-Hellman).

The size of public, prime and private key is 64 byte(512bit).
Prime is the constant of this schema, public key is static and private key is generating at process run.

There you go.

x_server should be a_server

I guess the shared key is the RC4 crypto key?
Seems not too difficult.

[WOST]

Doesn't matter, I showed you the scheme. Right, you need to get all the keys, then you can calculate the shared key.
Yep, it isn't too difficult, but your ASM should be an excelent to find the keys, replace, decrypt etc.
By the way, I've already reversed the client.

[WOST]

Hm, generally, I can help you with encryption and packets. But the question is in my desire...
Okay, if you need my help, write me here and we will discuss.

[cr0c]

Why the hell isn't this topic a sticky thread?

I have been looking for such valuable information on my own, and with the right keyword I've eventually ended up here.

Now I can tell you that I can (almost) deal a key with the server.