t.c.s.t.SSHServerTransport(SSHTransportBase) : class documentation

Part of twisted.conch.ssh.transport View Source View In Hierarchy

SSHServerTransport implements the server side of the SSH protocol.
Instance VariablesisClientsince we are never the client, this is always False.
ignoreNextPacketif True, ignore the next key exchange packet. This is set when the client sends a guessed key exchange packet but with an incorrect guess.
dhGexRequestthe KEX_DH_GEX_REQUEST(_OLD) that the client sent. The key generation needs this to be stored.
gthe Diffie-Hellman group generator.
pthe Diffie-Hellman group prime.
Method ssh_KEXINIT No summary
Method ssh_KEX_DH_GEX_REQUEST_OLD No summary
Method ssh_KEX_DH_GEX_REQUEST No summary
Method ssh_KEX_DH_GEX_INIT Called when we get a MSG_KEX_DH_GEX_INIT message. Payload:: integer e (client DH public key)
Method ssh_NEWKEYS Called when we get a MSG_NEWKEYS message. No payload. When we get this, the keys have been set on both sides, and we start using them to encrypt and authenticate the connection.
Method ssh_SERVICE_REQUEST Called when we get a MSG_SERVICE_REQUEST message. Payload:: string serviceName
Method _ssh_KEXDH_INIT Called to handle the beginning of a diffie-hellman-group1-sha1 key exchange.

Inherited from SSHTransportBase:

Method connectionLost Called when the connection is shut down.
Method connectionMade Called when the connection is made to the other side. We sent our version and the MSG_KEXINIT packet.
Method sendKexInit Send a KEXINIT message to initiate key exchange or to respond to a key exchange initiated by the peer.
Method sendPacket Sends a packet. If it's been set up, compress the data, encrypt it, and authenticate it before sending. If key exchange is in progress and the message is not part of key exchange, queue it to be sent later.
Method getPacket Try to return a decrypted, authenticated, and decompressed packet out of the buffer. If there is not enough data, return None.
Method dataReceived First, check for the version string (SSH-2.0-*). After that has been received, this method adds data to the buffer, and pulls out any packets.
Method dispatchMessage Send a received message to the appropriate method.
Method ssh_DISCONNECT Called when we receive a MSG_DISCONNECT message. Payload:: long code string description
Method ssh_IGNORE Called when we receieve a MSG_IGNORE message. No payload. This means nothing; we simply return.
Method ssh_UNIMPLEMENTED Called when we receieve a MSG_UNIMPLEMENTED message. Payload:: long packet
Method ssh_DEBUG No summary
Method setService Set our service to service and start it running. If we were running a service previously, stop it first.
Method sendDebug Send a debug message to the other side.
Method sendIgnore Send a message that will be ignored by the other side. This is useful to fool attacks based on guessing packet sizes in the encrypted stream.
Method sendUnimplemented Send a message to the other side that the last packet was not understood.
Method sendDisconnect Send a disconnect message to the other side and then disconnect.
Method isEncrypted Return True if the connection is encrypted in the given direction. Direction must be one of ["out", "in", "both"].
Method isVerified Return True if the connecction is verified/authenticated in the given direction. Direction must be one of ["out", "in", "both"].
Method loseConnection Lose the connection to the other side, sending a DISCONNECT_CONNECTION_LOST message.
Method receiveError Called when we receive a disconnect error message from the other side.
Method receiveUnimplemented Called when we receive an unimplemented packet message from the other side.
Method receiveDebug Called when we receive a debug message from the other side.
Method _allowedKeyExchangeMessageType Determine if the given message type may be sent while key exchange is in progress.
Method _unsupportedVersionReceived Called when an unsupported version of the ssh protocol is received from the remote endpoint.
Method _getKey Get one of the keys for authentication/encryption.
Method _keySetup Set up the keys for the connection and sends MSG_NEWKEYS when finished,
Method _newKeys No summary

Inherited from BaseProtocol (via SSHTransportBase, Protocol):

Method makeConnection Make a connection to a transport and a server.
def ssh_KEXINIT(self, packet): (source)
Called when we receive a MSG_KEXINIT message. For a description of the packet, see SSHTransportBase.ssh_KEXINIT(). Additionally, this method checks if a guessed key exchange packet was sent. If it was sent, and it guessed incorrectly, the next key exchange packet MUST be ignored.
def _ssh_KEXDH_INIT(self, packet): (source)

Called to handle the beginning of a diffie-hellman-group1-sha1 key exchange.

Unlike other message types, this is not dispatched automatically. It is called from ssh_KEX_DH_GEX_REQUEST_OLD because an extra check is required to determine if this is really a KEXDH_INIT message or if it is a KEX_DH_GEX_REQUEST_OLD message.

The KEXDH_INIT (for diffie-hellman-group1-sha1 exchanges) payload:
       integer e (the client's Diffie-Hellman public key)

   We send the KEXDH_REPLY with our host key and signature.
def ssh_KEX_DH_GEX_REQUEST_OLD(self, packet): (source)
This represents two different key exchange methods that share the same integer value. If the message is determined to be a KEXDH_INIT, _ssh_KEXDH_INIT is called to handle it. Otherwise, for KEX_DH_GEX_REQUEST_OLD (for diffie-hellman-group-exchange-sha1) payload:
       integer ideal (ideal size for the Diffie-Hellman prime)

   We send the KEX_DH_GEX_GROUP message with the group that is
   closest in size to ideal.
If we were told to ignore the next key exchange packet by ssh_KEXINIT, drop it on the floor and return.
def ssh_KEX_DH_GEX_REQUEST(self, packet): (source)
Called when we receive a MSG_KEX_DH_GEX_REQUEST message. Payload:
   integer minimum
   integer ideal
   integer maximum

The client is asking for a Diffie-Hellman group between minimum and maximum size, and close to ideal if possible. We reply with a MSG_KEX_DH_GEX_GROUP message.

If we were told to ignore the next key exchange packet by ssh_KEXINIT, drop it on the floor and return.
def ssh_KEX_DH_GEX_INIT(self, packet): (source)
Called when we get a MSG_KEX_DH_GEX_INIT message. Payload:
   integer e (client DH public key)
We send the MSG_KEX_DH_GEX_REPLY message with our host key and signature.
def ssh_NEWKEYS(self, packet): (source)
Called when we get a MSG_NEWKEYS message. No payload. When we get this, the keys have been set on both sides, and we start using them to encrypt and authenticate the connection.
def ssh_SERVICE_REQUEST(self, packet): (source)
Called when we get a MSG_SERVICE_REQUEST message. Payload:
   string serviceName
The client has requested a service. If we can start the service, start it; otherwise, disconnect with DISCONNECT_SERVICE_NOT_AVAILABLE.
API Documentation for Twisted, generated by pydoctor at 2011-10-27 16:27:37.