void SshIncomingPacket::decrypt()
{
Q_ASSERT(isComplete());
const quint32 netDataLength = length() + 4;
m_decrypter.decrypt(m_data, cipherBlockSize(),
netDataLength - cipherBlockSize());
const QByteArray &mac = m_data.mid(netDataLength, macLength());
if (mac != generateMac(m_decrypter, m_serverSeqNr)) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_MAC_ERROR,
"Message authentication failed.");
}
}
void SshIncomingPacket::calculateLength() const
{
Q_ASSERT(currentDataSize() >= minPacketSize());
#ifdef CREATOR_SSH_DEBUG
qDebug("Length field before decryption: %d-%d-%d-%d", m_data.at(0) & 0xff,
m_data.at(1) & 0xff, m_data.at(2) & 0xff, m_data.at(3) & 0xff);
#endif
m_decrypter.decrypt(m_data, 0, cipherBlockSize());
#ifdef CREATOR_SSH_DEBUG
qDebug("Length field after decryption: %d-%d-%d-%d", m_data.at(0) & 0xff, m_data.at(1) & 0xff, m_data.at(2) & 0xff, m_data.at(3) & 0xff);
qDebug("message type = %d", m_data.at(TypeOffset));
#endif
m_length = SshPacketParser::asUint32(m_data, static_cast<quint32>(0));
#ifdef CREATOR_SSH_DEBUG
qDebug("decrypted length is %u", m_length);
#endif
}
quint32 AbstractSshPacket::minPacketSize() const
{
return qMax<quint32>(cipherBlockSize(), 16) + macLength();
}
int SshOutgoingPacket::sizeDivisor() const
{
return qMax(cipherBlockSize(), 8U);
}