Function decryptMessageUpdate

packages/consortium-web/src/lib/socket.ts:178–195

(
  event: Extract<UpdateEvent, { type: 'new-message' }>,
  session: DecryptedSession,
)

 * Decrypt an incoming new-message update event
 */
export async function decryptMessageUpdate(
  event: Extract<UpdateEvent, { type: 'new-message' }>,
  session: DecryptedSession,
): Promise<MessageContent | null> {
  if (event.message.content?.t === 'encrypted' && event.message.content.c) {
    try {
      const decrypted = await decrypt(
        session.encryptionKey,
        session.encryptionVariant,
        decodeBase64(event.message.content.c),
      );
      return decrypted as MessageContent | null;
    } catch {
      return null;
    }
  }
  return null;
}