Package org.signal.libsignal.protocol.groups

Class GroupCipher

java.lang.Object

org.signal.libsignal.protocol.groups.GroupCipher

public class GroupCipher
extends java.lang.Object

The main entry point for Signal Protocol group encrypt/decrypt operations. Once a session has been established with GroupSessionBuilder and a SenderKeyDistributionMessage has been distributed to each member of the group, this class can be used for all subsequent encrypt/decrypt operations within that session (ie: until group membership changes). This class is not thread-safe.

Constructor Summary

Constructors

Constructor	Description
GroupCipher(SenderKeyStore senderKeyStore, SignalProtocolAddress sender)

Method Summary

Modifier and Type	Method	Description
byte[]	decrypt(byte[] senderKeyMessageBytes)	Decrypt a SenderKey group message.
CiphertextMessage	encrypt(java.util.UUID distributionId, byte[] paddedPlaintext)	Encrypt a message.

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupCipher

public GroupCipher(SenderKeyStore senderKeyStore,
                   SignalProtocolAddress sender)

Method Detail

encrypt

public CiphertextMessage encrypt(java.util.UUID distributionId,
                                 byte[] paddedPlaintext)
                          throws NoSessionException

Encrypt a message.

Parameters:

paddedPlaintext - The plaintext message bytes, optionally padded.

Returns:

Ciphertext.

Throws:

NoSessionException

decrypt

public byte[] decrypt(byte[] senderKeyMessageBytes)
               throws LegacyMessageException,
                      DuplicateMessageException,
                      InvalidMessageException,
                      NoSessionException

Decrypt a SenderKey group message.

Parameters:

senderKeyMessageBytes - The received ciphertext.

Returns:

Plaintext

Throws:

LegacyMessageException

InvalidMessageException

DuplicateMessageException

NoSessionException