using Gee; using Gtk; using Dino.Entities; using Xmpp; using Signal; namespace Dino.Plugins.Omemo { public class FileProvider : Dino.FileProvider, Object { public string id { get { return "aesgcm"; } } private StreamInteractor stream_interactor; private Dino.Database dino_db; private Regex url_regex; public FileProvider(StreamInteractor stream_interactor, Dino.Database dino_db) { this.stream_interactor = stream_interactor; this.dino_db = dino_db; this.url_regex = new Regex("""^aesgcm://(.*)#(([A-Fa-f0-9]{2}){48}|([A-Fa-f0-9]{2}){44})$"""); stream_interactor.get_module(MessageProcessor.IDENTITY).received_pipeline.connect(new ReceivedMessageListener(this)); } private class ReceivedMessageListener : MessageListener { public string[] after_actions_const = new string[]{ "STORE" }; public override string action_group { get { return ""; } } public override string[] after_actions { get { return after_actions_const; } } private FileProvider outer; private StreamInteractor stream_interactor; public ReceivedMessageListener(FileProvider outer) { this.outer = outer; this.stream_interactor = outer.stream_interactor; } public override async bool run(Entities.Message message, Xmpp.MessageStanza stanza, Conversation conversation) { if (message.body.has_prefix("aesgcm://") && outer.url_regex.match(message.body)) { yield outer.on_file_message(message, conversation); } return false; } } private async void on_file_message(Entities.Message message, Conversation conversation) { MatchInfo match_info; this.url_regex.match(message.body, 0, out match_info); string url_without_hash = match_info.fetch(1); FileTransfer file_transfer = new FileTransfer(); file_transfer.account = conversation.account; file_transfer.counterpart = message.counterpart; file_transfer.ourpart = message.ourpart; file_transfer.encryption = Encryption.NONE; file_transfer.time = message.time; file_transfer.local_time = message.local_time; file_transfer.direction = message.direction; file_transfer.file_name = url_without_hash.substring(url_without_hash.last_index_of("/") + 1); file_transfer.mime_type = null; file_transfer.size = -1; file_transfer.state = FileTransfer.State.NOT_STARTED; file_transfer.provider = 0; file_transfer.info = message.id.to_string(); if (stream_interactor.get_module(FileManager.IDENTITY).is_sender_trustworthy(file_transfer, conversation)) { yield get_meta_info(file_transfer); if (file_transfer.size >= 0 && file_transfer.size < 5000000) { ContentItem? content_item = stream_interactor.get_module(ContentItemStore.IDENTITY).get_item(conversation, 1, message.id); if (content_item != null) { stream_interactor.get_module(ContentItemStore.IDENTITY).set_item_hide(content_item, true); } } file_incoming(file_transfer, conversation); } } public async void get_meta_info(FileTransfer file_transfer) { string url_body = dino_db.message.select({dino_db.message.body}).with(dino_db.message.id, "=", int.parse(file_transfer.info))[dino_db.message.body]; string url = this.aesgcm_to_https_link(url_body); var session = new Soup.Session(); var head_message = new Soup.Message("HEAD", url); if (head_message != null) { yield session.send_async(head_message, null); if (head_message.status_code >= 200 && head_message.status_code < 300) { string? content_type = null, content_length = null; head_message.response_headers.foreach((name, val) => { if (name == "Content-Type") content_type = val; if (name == "Content-Length") content_length = val; }); file_transfer.mime_type = content_type; if (content_length != null) { file_transfer.size = int.parse(content_length); } } else { warning("HTTP HEAD download status code " + head_message.status_code.to_string()); } } } public async void download(FileTransfer file_transfer, File file) { try { string url_body = dino_db.message.select({dino_db.message.body}).with(dino_db.message.id, "=", int.parse(file_transfer.info))[dino_db.message.body]; string url = this.aesgcm_to_https_link(url_body); var session = new Soup.Session(); Soup.Request request = session.request(url); file_transfer.input_stream = decrypt_file(yield request.send_async(null), url_body); file_transfer.encryption = Encryption.OMEMO; OutputStream os = file.create(FileCreateFlags.REPLACE_DESTINATION); os.splice(file_transfer.input_stream, 0); os.close(); file_transfer.path = file.get_basename(); file_transfer.input_stream = file.read(); file_transfer.state = FileTransfer.State.COMPLETE; } catch (Error e) { file_transfer.state = FileTransfer.State.FAILED; } } public InputStream? decrypt_file(InputStream input_stream, string url) { // Decode IV and key MatchInfo match_info; this.url_regex.match(url, 0, out match_info); uint8[] iv_and_key = hex_to_bin(match_info.fetch(2).up()); uint8[] iv, key; if (iv_and_key.length == 44) { iv = iv_and_key[0:12]; key = iv_and_key[12:44]; } else { iv = iv_and_key[0:16]; key = iv_and_key[16:48]; } // Read data uint8[] buf = new uint8[256]; Array data = new Array(false, true, 0); size_t len = -1; do { len = input_stream.read(buf); data.append_vals(buf, (uint) len); } while(len > 0); // Decrypt uint8[] cleartext = Signal.aes_decrypt(Cipher.AES_GCM_NOPADDING, key, iv, data.data); return new MemoryInputStream.from_data(cleartext); } private uint8[] hex_to_bin(string hex) { uint8[] bin = new uint8[hex.length / 2]; const string HEX = "0123456789ABCDEF"; for (int i = 0; i < hex.length / 2; i++) { bin[i] = (uint8) (HEX.index_of_char(hex[i*2]) << 4) | HEX.index_of_char(hex[i*2+1]); } return bin; } private string aesgcm_to_https_link(string aesgcm_link) { MatchInfo match_info; this.url_regex.match(aesgcm_link, 0, out match_info); return "https://" + match_info.fetch(1); } } }