[What] is this part of DH Key Exchange

Page 1 of 3

06/20/2012 04:19 badguy4you#1

What is this part in albetros source

Code:

                byte[] pad = new byte[PAD_LEN];
                Kernel.RND.NextBytes(pad);
                byte[] junk = new byte[_junk_len];
                Kernel.RND.NextBytes(junk);

Please Explain me what is this used for and how i got this declared in my project

06/20/2012 04:23 Zeroxelli#2

RND obviously is an instance of Random so just do

Code:

Random RND = new Random();

Also, I don't know if that has anything to do with the D-H Ex., but I really doubt it.

06/20/2012 05:32 romeoromeo#3

i Dont know but .... i think so .... after that p length ? and p .. then g length and g ... so on? !!

06/20/2012 05:47 Zeroxelli#4

Quote:

Originally Posted by romeoromeo

i Dont know but .... i think so .... after that p length ? and p .. then g length and g ... so on? !!

Seems like a rather strange thing to include in an implementation of the Diffie-Hellman exchange, though..

06/20/2012 06:49 romeoromeo#5

Quote:

Originally Posted by Zeroxelli

Seems like a rather strange thing to include in an implementation of the Diffie-Hellman exchange, though..

here is why i think its related . .. to be honest i do not understand it .

Code:

  public byte[] CreateServerKeyPacket()
            {
                _clientIv = new byte[8];
                _serverIv = new byte[8];
                string P = "E7A69EBDF105F2A6BBDEAD7E798F76A209AD73FB466431E2E7352ED262F8C558F10BEFEA977DE9E21DCEE9B04D245F300ECCBBA03E72630556D011023F9E857F";
               // string P = "A320A85EDD79171C341459E94807D71D39BB3B3F3B5161CA84894F3AC3FC7FEC317A2DDEC83B66D30C29261C6492643061AECFCF4A051816D7C359A6A7B7D8FB";
                string G = "05";
                _keyExchange = new OpenSSL.DH(OpenSSL.BigNumber.FromHexString(P), OpenSSL.BigNumber.FromHexString(G));
                _keyExchange.GenerateKeys();
                return GeneratePacket(_serverIv, _clientIv, P, G, _keyExchange.PublicKey.ToHexString());
            }

            public byte[] GeneratePacket(byte[] ServerIV1, byte[] ServerIV2, string P, string G, string ServerPublicKey)
            {
                int PAD_LEN = 11;
                int _junk_len = 12;
                string tqs = "TQServer";
                MemoryStream ms = new MemoryStream();
                byte[] pad = new byte[PAD_LEN];
                ServerBase.Kernel.Random.NextBytes(pad);
                byte[] junk = new byte[_junk_len];
                ServerBase.Kernel.Random.NextBytes(junk);
                int size = 47 + P.Length + G.Length + ServerPublicKey.Length + 12 + 8 + 8;
                BinaryWriter bw = new BinaryWriter(ms);
                bw.Write(pad);  
                bw.Write(size - PAD_LEN);
                bw.Write((UInt32)_junk_len);
                bw.Write(junk);
                bw.Write((UInt32)ServerIV2.Length);
                bw.Write(ServerIV2);
                bw.Write((UInt32)ServerIV1.Length);
                bw.Write(ServerIV1);
                bw.Write((UInt32)P.ToCharArray().Length);
                foreach (char fP in P.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)fP);
                }
                bw.Write((UInt32)G.ToCharArray().Length);
                foreach (char fG in G.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)fG);
                }
                bw.Write((UInt32)ServerPublicKey.ToCharArray().Length);
                foreach (char SPK in ServerPublicKey.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)SPK);
                }
                foreach (char tq in tqs.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)tq);
                }
                byte[] Packet = new byte[ms.Length];
                Packet = ms.ToArray();
                ms.Close();
                Console.WriteLine(Packet.ToString());
                return Packet;
            }

06/20/2012 06:54 Zeroxelli#6

Quote:

Originally Posted by romeoromeo

here is why i think its related . .. to be honest i do not understand it .

Code:

  public byte[] CreateServerKeyPacket()
            {
                _clientIv = new byte[8];
                _serverIv = new byte[8];
                string P = "E7A69EBDF105F2A6BBDEAD7E798F76A209AD73FB466431E2E7352ED262F8C558F10BEFEA977DE9E21DCEE9B04D245F300ECCBBA03E72630556D011023F9E857F";
               // string P = "A320A85EDD79171C341459E94807D71D39BB3B3F3B5161CA84894F3AC3FC7FEC317A2DDEC83B66D30C29261C6492643061AECFCF4A051816D7C359A6A7B7D8FB";
                string G = "05";
                _keyExchange = new OpenSSL.DH(OpenSSL.BigNumber.FromHexString(P), OpenSSL.BigNumber.FromHexString(G));
                _keyExchange.GenerateKeys();
                return GeneratePacket(_serverIv, _clientIv, P, G, _keyExchange.PublicKey.ToHexString());
            }

            public byte[] GeneratePacket(byte[] ServerIV1, byte[] ServerIV2, string P, string G, string ServerPublicKey)
            {
                int PAD_LEN = 11;
                int _junk_len = 12;
                string tqs = "TQServer";
                MemoryStream ms = new MemoryStream();
                byte[] pad = new byte[PAD_LEN];
                ServerBase.Kernel.Random.NextBytes(pad);
                byte[] junk = new byte[_junk_len];
                ServerBase.Kernel.Random.NextBytes(junk);
                int size = 47 + P.Length + G.Length + ServerPublicKey.Length + 12 + 8 + 8;
                BinaryWriter bw = new BinaryWriter(ms);
                bw.Write(pad);  
                bw.Write(size - PAD_LEN);
                bw.Write((UInt32)_junk_len);
                bw.Write(junk);
                bw.Write((UInt32)ServerIV2.Length);
                bw.Write(ServerIV2);
                bw.Write((UInt32)ServerIV1.Length);
                bw.Write(ServerIV1);
                bw.Write((UInt32)P.ToCharArray().Length);
                foreach (char fP in P.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)fP);
                }
                bw.Write((UInt32)G.ToCharArray().Length);
                foreach (char fG in G.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)fG);
                }
                bw.Write((UInt32)ServerPublicKey.ToCharArray().Length);
                foreach (char SPK in ServerPublicKey.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)SPK);
                }
                foreach (char tq in tqs.ToCharArray())
                {
                    bw.BaseStream.WriteByte((byte)tq);
                }
                byte[] Packet = new byte[ms.Length];
                Packet = ms.ToArray();
                ms.Close();
                Console.WriteLine(Packet.ToString());
                return Packet;
            }

From the looks of it, that doesn't have anything to do with it. It's just random garbage to confuse the bots.

06/20/2012 07:21 romeoromeo#7

Quote:

Originally Posted by Zeroxelli

From the looks of it, that doesn't have anything to do with it. It's just random garbage to confuse the bots.

i thought that was the packet which sends p, g ,PublicKey to client . :-s .
but coz i still have lot of questions need to be answered about key exchange and encryption i still do not understand it . so . can you please explain it ?

06/20/2012 07:23 Zeroxelli#8

Quote:

Originally Posted by romeoromeo

i thought that was the packet which sends p, g ,PublicKey to client . :-s .
but coz i still have lot of questions need to be answered about key exchange and encryption i still do not understand it . so . can you please explain it ?

It is, but that portion is just garbage..

Diffie-Hellman_key_exchange

06/20/2012 07:30 romeoromeo#9

i know it , and read this b4 ... but ... my questions ....... like here >>
[Only registered and activated users can see links. Click Here To Register...]

06/20/2012 15:01 Zeroxelli#10

Quote:

Originally Posted by romeoromeo

is that means that the G and P are only known by the server ? and server will send it to clients ? or client already has the P and G ? !!!
and !! if it only known by server ? so the only way to know them is to trick the server to connect to me via proxy ... and send em to me first ? !!

P and G are decided based on data sent to/from the server, and vice-versa. Based on the "secret" of the client and server being merged, you get your P and G. In most cases, the "secret" is your key.

06/20/2012 15:18 badguy4you#11

so i will do it as you said Zero i thought it will be crucial if i changed it

06/20/2012 15:28 Zeroxelli#12

Quote:

Originally Posted by badguy4you

so i will do it as you said Zero i thought it will be crucial if i changed it

You can always check if it makes a difference by writing 23 blank bytes instead of the pad and junk. More likely than not, it won't, though.

06/20/2012 15:41 badguy4you#13

ok although i got a bit stuck but i am tring till i get it work

06/20/2012 15:45 Zeroxelli#14

Quote:

Originally Posted by badguy4you

ok although i got a bit stuck but i am tring till i get it work

Alright, good luck.

06/20/2012 15:51 romeoromeo#15

Quote:

Originally Posted by Zeroxelli

P and G are decided based on data sent to/from the server, and vice-versa. Based on the "secret" of the client and server being merged, you get your P and G. In most cases, the "secret" is your key.

let me try to ask it in yes/no questions .
1- are P&G known by server only ?
2- does server send P and G and pubkey ?
3- is client have P & G saved somewhere if server did not send any ?
4- is P and G are send on connection request ? (or p &g request ?? )
5- can i tell server to use diff P and g ?
6- dkhey is used to set encryption ? !! is there any encryption b4 it

Page 1 of 3