使用@signalapp/libsignal-client时收到PreKeySignalMessage而非SignalMessage的问题

我正尝试在TypeScript中实现Signal协议，使用*@signalapp/libsignal-client库，但找不到相关实现文档。当前核心问题是：接收端始终收到PreKeySignalMessage*，而我预期应该收到SignalMessage。

相关代码 #

发送群消息函数

async function sendGroupMessage(
    senderId: string,
    groupMembers: string[],
    message: string,
    sessionStore: SessionStore,
    identityStore: IdentityKeyStore
): Promise<Map<string, CiphertextMessage>> {
    const encryptedMessages = new Map<string, CiphertextMessage>();

    for (const memberId of groupMembers) {
        if (memberId !== senderId) {
            const address = ProtocolAddress.new(memberId, 1);

            const encryptedMessage = await signalEncrypt(
                Buffer.from(message, 'utf-8'),
                address,
                sessionStore,
                identityStore,
                new Date()
            );
            encryptedMessages.set(memberId, encryptedMessage);
        }
    }

    return encryptedMessages;
}

接收群消息函数

async function receiveGroupMessage(
    receiverId: string,
    senderId: string,
    encryptedMessage: CiphertextMessage,
    sessionStore: SessionStore,
    identityStore: IdentityKeyStore
): Promise<string> {
    const address = ProtocolAddress.new(senderId, 1);

    const messageType = encryptedMessage.type();
    switch (messageType) {
        case CiphertextMessageType.Whisper: {
            const signalMessage = SignalMessage.deserialize(encryptedMessage.serialize());
            const decryptedContent = await signalDecrypt(
                signalMessage,
                address,
                sessionStore,
                identityStore
            );
            return decryptedContent.toString('utf-8');
        }
        case CiphertextMessageType.PreKey: {
            console.error("Unexpected PreKeySignalMessage received. The session might not have been established correctly.");
            return "Error: PreKeySignalMessage received instead of SignalMessage.";
        }
        default:
            throw new Error(`Unsupported message type: ${messageType}`);
    }
}

运行环境 #

Node.js 18+

内容的提问来源于stack exchange，提问作者alisterion