bool AbstractSshPacket::isComplete() const
{
if (currentDataSize() < minPacketSize())
return false;
Q_ASSERT(4 + length() + macLength() >= currentDataSize());
return 4 + length() + macLength() == currentDataSize();
}
void SshIncomingPacket::consumeData(QByteArray &newData)
{
#ifdef CREATOR_SSH_DEBUG
qDebug("%s: current data size = %d, new data size = %d",
Q_FUNC_INFO, m_data.size(), newData.size());
#endif
if (isComplete() || newData.isEmpty())
return;
/*
* Until we have reached the minimum packet size, we cannot decrypt the
* length field.
*/
const quint32 minSize = minPacketSize();
if (currentDataSize() < minSize) {
const int bytesToTake
= qMin<quint32>(minSize - currentDataSize(), newData.size());
moveFirstBytes(m_data, newData, bytesToTake);
#ifdef CREATOR_SSH_DEBUG
qDebug("Took %d bytes from new data", bytesToTake);
#endif
if (currentDataSize() < minSize)
return;
}
if (4 + length() + macLength() < currentDataSize())
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR, "Server sent invalid packet.");
const int bytesToTake
= qMin<quint32>(length() + 4 + macLength() - currentDataSize(),
newData.size());
moveFirstBytes(m_data, newData, bytesToTake);
#ifdef CREATOR_SSH_DEBUG
qDebug("Took %d bytes from new data", bytesToTake);
#endif
if (isComplete()) {
#ifdef CREATOR_SSH_DEBUG
qDebug("Message complete. Overall size: %u, payload size: %u",
m_data.size(), m_length - paddingLength() - 1);
#endif
decrypt();
++m_serverSeqNr;
}
}
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
}
SshKeyExchangeReply SshIncomingPacket::extractKeyExchangeReply(const QByteArray &pubKeyAlgo) const
{
Q_ASSERT(isComplete());
Q_ASSERT(type() == SSH_MSG_KEXDH_REPLY);
try {
SshKeyExchangeReply replyData;
quint32 offset = TypeOffset + 1;
const quint32 k_sLength
= SshPacketParser::asUint32(m_data, &offset);
if (offset + k_sLength > currentDataSize())
throw SshPacketParseException();
replyData.k_s = m_data.mid(offset - 4, k_sLength + 4);
if (SshPacketParser::asString(m_data, &offset) != pubKeyAlgo)
throw SshPacketParseException();
// DSS: p and q, RSA: e and n
replyData.parameters << SshPacketParser::asBigInt(m_data, &offset);
replyData.parameters << SshPacketParser::asBigInt(m_data, &offset);
// g and y
if (pubKeyAlgo == SshCapabilities::PubKeyDss) {
replyData.parameters << SshPacketParser::asBigInt(m_data, &offset);
replyData.parameters << SshPacketParser::asBigInt(m_data, &offset);
}
replyData.f = SshPacketParser::asBigInt(m_data, &offset);
offset += 4;
if (SshPacketParser::asString(m_data, &offset) != pubKeyAlgo)
throw SshPacketParseException();
replyData.signatureBlob = SshPacketParser::asString(m_data, &offset);
return replyData;
} catch (SshPacketParseException &) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
"Key exchange failed: "
"Server sent invalid SSH_MSG_KEXDH_REPLY packet.");
}
}
