private byte[] decrypt(SessionState sessionState, WhisperMessage ciphertextMessage)
		{
			if (!sessionState.hasSenderChain())
			{
				throw new InvalidMessageException("Uninitialized session!");
			}

			if (ciphertextMessage.getMessageVersion() != sessionState.getSessionVersion())
			{
				throw new InvalidMessageException($"Message version {ciphertextMessage.getMessageVersion()}, but session version {sessionState.getSessionVersion()}");
			}

			uint messageVersion = ciphertextMessage.getMessageVersion();
			ECPublicKey theirEphemeral = ciphertextMessage.getSenderRatchetKey();
			uint counter = ciphertextMessage.getCounter();
			ChainKey chainKey = getOrCreateChainKey(sessionState, theirEphemeral);
			MessageKeys messageKeys = getOrCreateMessageKeys(sessionState, theirEphemeral,
																	  chainKey, counter);

		/*	ciphertextMessage.verifyMac(messageVersion,
											sessionState.getRemoteIdentityKey(),
											sessionState.getLocalIdentityKey(),
											messageKeys.getMacKey());*/

			byte[] plaintext = getPlaintext(messageVersion, messageKeys, ciphertextMessage.getBody());

			sessionState.clearUnacknowledgedPreKeyMessage();

			return plaintext;
		}