From e8664e27303e6028bc335e33172d84025ff3fa30 Mon Sep 17 00:00:00 2001 From: Maximilian Wuttke Date: Mon, 29 Mar 2021 21:53:51 +0200 Subject: OMEMO: Fail if message keys couldn't be encrypted for any recipient device If the message (key) can't be encrypted for any device, sending the message is refused and an informative error message is presented to the user. Also, don't encrypt for the same device, since the OMEMO XEP disallows this. --- src/omemo/omemo.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'src/omemo') diff --git a/src/omemo/omemo.c b/src/omemo/omemo.c index a552cd57..495842bf 100644 --- a/src/omemo/omemo.c +++ b/src/omemo/omemo.c @@ -705,6 +705,7 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_ memcpy(key_tag, key, AES128_GCM_KEY_LENGTH); memcpy(key_tag + AES128_GCM_KEY_LENGTH, tag, AES128_GCM_TAG_LENGTH); + // List of barejids of the recipients of this message GList* recipients = NULL; if (muc) { ProfMucWin* mucwin = (ProfMucWin*)win; @@ -727,6 +728,7 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_ omemo_ctx.identity_key_store.recv = false; + // Encrypt keys for the recipients GList* recipients_iter; for (recipients_iter = recipients; recipients_iter != NULL; recipients_iter = recipients_iter->next) { GList* recipient_device_id = NULL; @@ -772,6 +774,17 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_ g_list_free_full(recipients, free); + // Don't send the message if no key could be encrypted. + // (Since none of the recipients would be able to read the message.) + if (keys == NULL) { + win_println(win, THEME_ERROR, "!", "This message cannot be decrypted for any recipient.\n" + "You should trust your recipients' device fingerprint(s) using \"/omemo fingerprint trust FINGERPRINT\".\n" + "It could also be that the key bundle of the recipient(s) have not been received. " + "In this case, you could try \"omemo end\", \"omemo start\", and send the message again."); + goto out; + } + + // Encrypt keys for the sender if (!muc) { GList* sender_device_id = g_hash_table_lookup(omemo_ctx.device_list, jid->barejid); for (device_ids_iter = sender_device_id; device_ids_iter != NULL; device_ids_iter = device_ids_iter->next) { @@ -784,6 +797,12 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_ .device_id = GPOINTER_TO_INT(device_ids_iter->data) }; + // Don't encrypt for this device (according to + // ). + if (address.device_id == omemo_ctx.device_id) { + continue; + } + res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal); if (res != 0) { log_error("[OMEMO] cannot create cipher for %s device id %d", address.name, address.device_id); @@ -808,6 +827,7 @@ omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_ } } + // Send the message if (muc) { ProfMucWin* mucwin = (ProfMucWin*)win; assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK); -- cgit 1.4.1-2-gfad0