#include "stdafx.h"

RealmSocket::RealmSocket(SocketHandler &h) : TcpSocket(h)
{
    N.SetHexStr("894B645E89E1535BBDAD5B8B290650530801B18EBFBF5E8FAB3C82872A3E9BB7");
    g.SetDword(7);
    _authed = false;
    acct = NULL;
}

RealmSocket::~RealmSocket()
{

}

void RealmSocket::OnAccept()
{
    TcpSocket::OnAccept();
    Log.Text("[REALMLIST] Connection accepted from %s", GetRemoteAddress().c_str());
    s.SetRand(s_BYTE_SIZE * 8);
}

void RealmSocket::OnRead()
{
    TcpSocket::OnRead();

    if(!ibuf.GetLength())
        return; // abort on no data

    unsigned char cmdid = 0;
    ibuf.SoftRead((char*)&cmdid, sizeof(unsigned char));

    switch(cmdid)
    {
    case 0x00:  // CLIENT LOGON CHALLENGE
        this->_HandleLogonChallenge();
        break;
    case 0x01:  // CLIENT LOGON PROOF
        this->_HandleLogonProof();
        break;
    case 0x10:  // CLIENT REALM LIST
        this->_HandleRealmList();
        break;
    default:
        Log.Text("[REALMLIST] Received unknown cmdid: %d of size %u", cmdid, ibuf.GetLength());
        break;
    }
}

void RealmSocket::_HandleLogonChallenge()
{
    if(ibuf.GetLength() < 4)
        return;     // wtf?

    std::vector<uint8> buf;
    buf.resize(4);
    ibuf.Read((char*)&buf[0], 4);

    uint16 r = ((sAuthLogonChallenge_C *)&buf[0])->size;
    Log.Text("[REALMLIST] Got Auth Challenge Header. Body is %u bytes.", r);

    if(ibuf.GetLength() < r)
        return; // incomplete packet

    buf.resize(r+ buf.size() + 1);
    buf[buf.size() - 1] = 0;
    ibuf.Read((char *)&buf[4], r);

    sAuthLogonChallenge_C *ch = (sAuthLogonChallenge_C*)&buf[0];

    Log.Text("[REALMLIST] Got full packet. Client is build %u.", ch->build);

    Log.Text("            Username: %s", (const char*)ch->I);

    acct = AccountMgr.GetAccount((const char*)ch->I);
    if(!acct)
    {
        acct = AccountMgr.AddAccount((const char*)ch->I, "NOPASS");
    }
    ByteBuffer outpacket;

    if(!acct)
    {
        outpacket << uint8(AUTH_LOGON_CHALLENGE);
        outpacket << uint8(0);
        outpacket << uint8(0x04);
    }
    else
    {
        outpacket << uint8(AUTH_LOGON_CHALLENGE);
        outpacket << uint8(0);
        outpacket << uint8(0x00);

        password = acct->password;
        username = acct->username;

        Sha1Hash I;
        std::string sI = username + ":" + password;
        I.UpdateData(sI);
        I.Finalize();

        Sha1Hash sha;
        sha.UpdateData(s.AsByteArray(), s.GetNumBytes());
        sha.UpdateData(I.GetDigest(), SHA_DIGEST_LENGTH);
        sha.Finalize();

        BigNumber x;
        x.SetBinary(sha.GetDigest(), sha.GetLength());

        v = g.ModExp(x, N);
        b.SetRand(19 * 8);

        BigNumber gmod = g.ModExp(b, N);
        B = ((v * 3) + gmod) % N;
        ASSERT(gmod.GetNumBytes() <= 32);

        BigNumber unk3;
        unk3.SetRand(16*8);

        outpacket.append(B.AsByteArray(), 32);
        outpacket // g_len, g
            << (uint8)1;
        outpacket.append(g.AsByteArray(), 1);
        // N_len, N
        outpacket << (uint8)32;
        outpacket.append(N.AsByteArray(), 32);

        outpacket.append(s.AsByteArray(), s.GetNumBytes());
        outpacket.append(unk3.AsByteArray(), 16);
        outpacket << uint8(0x00);     // new in 1.11
    }

    SendBuf(((char*)outpacket.contents()), outpacket.size());
}

void RealmSocket::_HandleLogonProof()
{
    Log.Text("[REALMLIST] Got Logon Proof. Checking.");

    sAuthLogonProof_C lp;
    ibuf.Read((char *)&lp, sizeof(sAuthLogonProof_C));

    BigNumber A;
    A.SetBinary(lp.A, 32);

    Sha1Hash sha;
    sha.UpdateBigNumbers(&A, &B, NULL);
    sha.Finalize();
    BigNumber u;
    u.SetBinary(sha.GetDigest(), 20);
    BigNumber S = (A * (v.ModExp(u, N))).ModExp(b, N);

    uint8 t[32];
    uint8 t1[16];
    uint8 vK[40];
    memcpy(t, S.AsByteArray(), 32);
    for (int i = 0; i < 16; i++)
    {
        t1[i] = t[i*2];
    }
    sha.Initialize();
    sha.UpdateData(t1, 16);
    sha.Finalize();
    for (int i = 0; i < 20; i++)
    {
        vK[i*2] = sha.GetDigest()[i];
    }
    for (int i = 0; i < 16; i++)
    {
        t1[i] = t[i*2+1];
    }
    sha.Initialize();
    sha.UpdateData(t1, 16);
    sha.Finalize();
    for (int i = 0; i < 20; i++)
    {
        vK[i*2+1] = sha.GetDigest()[i];
    }
    K.SetBinary(vK, 40);

    uint8 hash[20];

    sha.Initialize();
    sha.UpdateBigNumbers(&N, NULL);
    sha.Finalize();
    memcpy(hash, sha.GetDigest(), 20);
    sha.Initialize();
    sha.UpdateBigNumbers(&g, NULL);
    sha.Finalize();
    for (int i = 0; i < 20; i++)
    {
        hash[i] ^= sha.GetDigest()[i];
    }
    BigNumber t3;
    t3.SetBinary(hash, 20);

    sha.Initialize();
    sha.UpdateData(username);
    sha.Finalize();
    BigNumber t4;
    t4.SetBinary(sha.GetDigest(), 20);

    sha.Initialize();
    sha.UpdateBigNumbers(&t3, &t4, &s, &A, &B, &K, NULL);
    sha.Finalize();
    BigNumber M;
    M.SetBinary(sha.GetDigest(), 20);

    if (!memcmp(M.AsByteArray(), lp.M1, 20))
    {
        Log.Text("           Successful.");
        //memcpy(acct->sessionkey, K.AsHexStr(), 40);
        acct->sessionkey = K.AsHexStr();

        sha.Initialize();
        sha.UpdateBigNumbers(&A, &M, &K, NULL);
        sha.Finalize();

        sAuthLogonProof_S proof;
        memcpy(proof.M2, sha.GetDigest(), 20);
        proof.cmd = AUTH_LOGON_PROOF;
        proof.error = 0;
        proof.unk2 = 0;
        proof.unk203 = 0;
        proof.unk203_more = 0;

        SendBuf((char *)&proof, sizeof(proof));
    }
    else
    {
        ByteBuffer pkt;
        pkt << (uint8) AUTH_LOGON_PROOF;
        pkt << (uint8) 4; // bad password
        pkt << (uint32) 3;

        SendBuf((char *)pkt.contents(), pkt.size());
    }
}

void RealmSocket::_HandleRealmList()
{
    // static realmlist for now.
    ByteBuffer pkt;

    if (ibuf.GetLength() < 5)
        return;
    ibuf.Remove(5);

    pkt << uint8(REALM_LIST);
    pkt << uint16(0);   // size placeholder

    pkt << uint32(0);
    pkt << uint16(1);

    pkt << uint8(1);//type
    pkt << uint8(0);//lock
    pkt << uint8(0);//offline
    pkt << "Burlex WotLK Sandbox";
    pkt << "127.0.0.1:3725";
    pkt << float(1.6); //pop
    pkt << uint8(1); //ch count
    pkt << uint8(1); //realm category
    pkt << uint8(6); //unk
    pkt << uint8(0); //unk
    pkt << uint8(0x17);//unk

    *(uint16*)&pkt.contents()[1] = (pkt.size() - 3);

    SendBuf((char*)pkt.contents(), pkt.size());
}