Package org.signal.libsignal.protocol

Class SessionBuilder

java.lang.Object

org.signal.libsignal.protocol.SessionBuilder

public class SessionBuilder
extends java.lang.Object

SessionBuilder is responsible for setting up encrypted sessions. Once a session has been established, SessionCipher can be used to encrypt/decrypt messages in that session.

Sessions are built from one of three different possible vectors:

1. A PreKeyBundle retrieved from a server.
2. A PreKeySignalMessage received from a client.

Sessions are constructed per recipientId + deviceId tuple. Remote logical users are identified by their recipientId, and each logical recipientId can have multiple physical devices. This class is not thread-safe.

Constructor Summary

Constructors

Constructor	Description
SessionBuilder(SessionStore sessionStore, PreKeyStore preKeyStore, SignedPreKeyStore signedPreKeyStore, IdentityKeyStore identityKeyStore, SignalProtocolAddress remoteAddress)	Constructs a SessionBuilder.
SessionBuilder(SignalProtocolStore store, SignalProtocolAddress remoteAddress)	Constructs a SessionBuilder

Method Summary

Modifier and Type	Method	Description
void	process(PreKeyBundle preKey)	Build a new session from a PreKeyBundle retrieved from a server.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SessionBuilder

public SessionBuilder(SessionStore sessionStore,
                      PreKeyStore preKeyStore,
                      SignedPreKeyStore signedPreKeyStore,
                      IdentityKeyStore identityKeyStore,
                      SignalProtocolAddress remoteAddress)

Constructs a SessionBuilder.

Parameters:

sessionStore - The SessionStore to store the constructed session in.

preKeyStore - The PreKeyStore where the client's local PreKeyRecords are stored.

identityKeyStore - The IdentityKeyStore containing the client's identity key information.

remoteAddress - The address of the remote user to build a session with.

SessionBuilder

public SessionBuilder(SignalProtocolStore store,
                      SignalProtocolAddress remoteAddress)

Constructs a SessionBuilder

Parameters:

store - The SignalProtocolStore to store all state information in.

remoteAddress - The address of the remote user to build a session with.

Method Detail

process

public void process(PreKeyBundle preKey)
             throws InvalidKeyException,
                    UntrustedIdentityException

Build a new session from a PreKeyBundle retrieved from a server.

Parameters:

preKey - A PreKey for the destination recipient, retrieved from a server.

Throws:

InvalidKeyException - when the PreKeyBundle is badly formatted.

UntrustedIdentityException - when the sender's IdentityKey is not trusted.