twisted.conch.ssh.transport.SSHServerTransport : API documentation

SSHServerTransport implements the server side of the SSH protocol.

Instance Variables	isClient	since we are never the client, this is always False.
	ignoreNextPacket	if True, ignore the next key exchange packet. This is set when the client sends a guessed key exchange packet but with an incorrect guess.
	dhGexRequest	the KEX_DH_GEX_REQUEST(_OLD) that the client sent. The key generation needs this to be stored.
	g	the Diffie-Hellman group generator.
	p	the Diffie-Hellman group prime.

Method	ssh_KEXINIT	Called when we receive a MSG_KEXINIT message. For a description
Method	ssh_KEX_DH_GEX_REQUEST_OLD	This represents two different key exchange methods that share the same
Method	ssh_KEX_DH_GEX_REQUEST	Called when we receive a MSG_KEX_DH_GEX_REQUEST message. Payload:
Method	ssh_KEX_DH_GEX_INIT	Called when we get a MSG_KEX_DH_GEX_INIT message. Payload:
Method	ssh_NEWKEYS	Called when we get a MSG_NEWKEYS message. No payload.
Method	ssh_SERVICE_REQUEST	Called when we get a MSG_SERVICE_REQUEST message. Payload:
Method	_ssh_KEXDH_INIT	Called to handle the beginning of a diffie-hellman-group1-sha1 key

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
Method	sendKexInit	Send a KEXINIT message to initiate key exchange or to respond to a
Method	sendPacket	Sends a packet. If it's been set up, compress the data, encrypt it, and
Method	getPacket	Try to return a decrypted, authenticated, and decompressed packet
Method	dataReceived	First, check for the version string (SSH-2.0-*). After that has been
Method	dispatchMessage	Send a received message to the appropriate method.
Method	ssh_DISCONNECT	Called when we receive a MSG_DISCONNECT message. Payload:
Method	ssh_IGNORE	Called when we receieve a MSG_IGNORE message. No payload.
Method	ssh_UNIMPLEMENTED	Called when we receieve a MSG_UNIMPLEMENTED message. Payload:
Method	ssh_DEBUG	Called when we receieve a MSG_DEBUG message. Payload:
Method	setService	Set our service to service and start it running. If we were
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
Method	sendUnimplemented	Send a message to the other side that the last packet was not
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.
Method	isVerified	Return True if the connecction is verified/authenticated in the
Method	loseConnection	Lose the connection to the other side, sending a
Method	receiveError	Called when we receive a disconnect error message from the other
Method	receiveUnimplemented	Called when we receive an unimplemented packet message from the other
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
Method	_unsupportedVersionReceived	Called when an unsupported version of the ssh protocol is received from
Method	_getKey	Get one of the keys for authentication/encryption.
Method	_keySetup	Set up the keys for the connection and sends MSG_NEWKEYS when
Method	_newKeys	Called back by a subclass once a MSG_NEWKEYS message has been

Inherited from BaseProtocol (via SSHTransportBase, Protocol):

Method

makeConnection

Make a connection to a transport and a server.

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.

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.

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.

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.

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.

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.

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.

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