org.eclipse.californium.scandium.dtls

Interface SessionCache

All Known Subinterfaces:

ClientSessionCache

public interface SessionCache

A second level cache for current state of DTLS sessions.

Session state can be put to the cache and later retrieved by the DTLS session's ID for resumption handshakes. The provided cache is required to be thread-safe because it will be accessed concurrently.

Note: get(SessionId) is called to validate session ids, if DtlsConnectorConfig.getVerifyPeersOnResumptionThreshold() is larger than 0. If the implementation is expensive, please ensure, that the value is configured with 0. Otherwise, CLIENT_HELLOs with invalid session ids may be spoofed and gets too expensive.

Method Summary

Methods

Modifier and Type	Method and Description
SessionTicket	get(SessionId id) Gets a session from the cache.
void	put(DTLSSession session) Adds an established session to the cache.
void	remove(SessionId id) Removes a session from the cache.

Method Detail

put

void put(DTLSSession session)

Adds an established session to the cache. If the session doesn't support resumption (session id is empty), it's not added to the cache

Parameters:

session - The session to add.

get

SessionTicket get(SessionId id)

Gets a session from the cache. Note: This method is called to validate session ids, if DtlsConnectorConfig.getVerifyPeersOnResumptionThreshold() is larger than 0. If this implementation is expensive, please ensure, that the value is configured with 0. Otherwise, CLIENT_HELLOs with invalid session ids may be spoofed and gets too expensive.

Parameters:

id - The session identifier to look up.

Returns:

a session ticker for the session with the given ID, or null, if the cache does not contain a session with the given ID. A returned ticket is to be destroyed after usage. The session ticket can only be used for resumption handshakes.

remove

void remove(SessionId id)

Removes a session from the cache.

Parameters:

id - The identifier of the session to remove.