feat: log the logic for (not) doing AEAP

This commit is contained in:
link2xt
2024-10-17 20:27:32 +00:00
parent 9e88764a8a
commit 3d07db6e62

View File

@@ -766,23 +766,65 @@ pub(crate) async fn maybe_do_aeap_transition(
// If the from addr is different from the peerstate address we know,
// we may want to do an AEAP transition.
if !addr_cmp(&peerstate.addr, &mime_parser.from.addr)
// Check if it's a chat message; we do this to avoid
// some accidental transitions if someone writes from multiple
// addresses with an MUA.
&& mime_parser.has_chat_version()
// Check if the message is encrypted and signed correctly. If it's not encrypted, it's
// probably from a new contact sharing the same key.
&& !mime_parser.signatures.is_empty()
// Check if the From: address was also in the signed part of the email.
// Without this check, an attacker could replay a message from Alice
// to Bob. Then Bob's device would do an AEAP transition from Alice's
// to the attacker's address, allowing for easier phishing.
&& mime_parser.from_is_signed
// DC avoids sending messages with the same timestamp, that's why `>` is here unlike in
// `Peerstate::apply_header()`.
&& info.message_time > peerstate.last_seen
{
if !addr_cmp(&peerstate.addr, &mime_parser.from.addr) {
// Check if it's a chat message; we do this to avoid
// some accidental transitions if someone writes from multiple
// addresses with an MUA.
if !mime_parser.has_chat_version() {
info!(
context,
"Not doing AEAP from {} to {} because the message is not a chat message.",
&peerstate.addr,
&mime_parser.from.addr
);
return Ok(());
}
// Check if the message is encrypted and signed correctly. If it's not encrypted, it's
// probably from a new contact sharing the same key.
if mime_parser.signatures.is_empty() {
info!(
context,
"Not doing AEAP from {} to {} because the message is not encrypted and signed.",
&peerstate.addr,
&mime_parser.from.addr
);
return Ok(());
}
// Check if the From: address was also in the signed part of the email.
// Without this check, an attacker could replay a message from Alice
// to Bob. Then Bob's device would do an AEAP transition from Alice's
// to the attacker's address, allowing for easier phishing.
if !mime_parser.from_is_signed {
info!(
context,
"Not doing AEAP from {} to {} because From: is not signed.",
&peerstate.addr,
&mime_parser.from.addr
);
return Ok(());
}
// DC avoids sending messages with the same timestamp, that's why messages
// with equal timestamps are ignored here unlike in `Peerstate::apply_header()`.
if info.message_time <= peerstate.last_seen {
info!(
context,
"Not doing AEAP from {} to {} because {} < {}.",
&peerstate.addr,
&mime_parser.from.addr,
info.message_time,
peerstate.last_seen
);
return Ok(());
}
info!(
context,
"Doing AEAP transition from {} to {}.", &peerstate.addr, &mime_parser.from.addr
);
let info = &mut mime_parser.decryption_info;
let peerstate = info.peerstate.as_mut().context("no peerstate??")?;
// Add info messages to chats with this (verified) contact