Mirrors/chatmail-core
1
0
Fork 0
mirror of https://github.com/chatmail/core.git synced 2026-04-17 21:46:35 +03:00
Code Issues Packages Projects Releases Wiki Activity

feat: mimeparser: Omit Legacy Display Elements (#7130)

Browse Source 
Omit Legacy Display Elements from "text/plain" and "text/html" (implement 4.5.3.{2,3} of
https://www.rfc-editor.org/rfc/rfc9788 "Header Protection for Cryptographically Protected Email").
This commit is contained in:
iequidoo
2025-10-28 04:48:15 -03:00
committed by iequidoo
parent 966ea28f83
commit e2ae6ae013
7 changed files with 140 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/config.rs
View File

@@ -438,6 +438,11 @@ pub enum Config {
/// storing the same token multiple times on the server.
EncryptedDeviceToken,
/// Enables running test hooks, e.g. see `InnerContext::pre_encrypt_mime_hook`.
/// This way is better than conditional compilation, i.e. `#[cfg(test)]`, because tests not
/// using this still run unmodified code.
TestHooks,
/// Return an error from `receive_imf_inner()` for a fully downloaded message. For tests.
FailOnReceivingFullMsg,
}

19
src/context.rs
View File

@@ -303,6 +303,17 @@ pub struct InnerContext {
/// `Connectivity` values for mailboxes, unordered. Used to compute the aggregate connectivity,
/// see [`Context::get_connectivity()`].
pub(crate) connectivities: parking_lot::Mutex<Vec<ConnectivityStore>>,
#[expect(clippy::type_complexity)]
/// Transforms the root of the cryptographic payload before encryption.
pub(crate) pre_encrypt_mime_hook: parking_lot::Mutex<
Option<
for<'a> fn(
&Context,
mail_builder::mime::MimePart<'a>,
) -> mail_builder::mime::MimePart<'a>,
>,
>,
}
/// The state of ongoing process.
@@ -467,6 +478,7 @@ impl Context {
iroh: Arc::new(RwLock::new(None)),
self_fingerprint: OnceLock::new(),
connectivities: parking_lot::Mutex::new(Vec::new()),
pre_encrypt_mime_hook: None.into(),
};
let ctx = Context {
@@ -1051,6 +1063,13 @@ impl Context {
.await?
.to_string(),
);
res.insert(
"test_hooks",
self.sql
.get_raw_config("test_hooks")
.await?
.unwrap_or_default(),
);
res.insert(
"fail_on_receiving_full_msg",
self.sql

46
src/dehtml.rs
View File

@@ -13,6 +13,7 @@ use quick_xml::{
use crate::simplify::{SimplifiedText, simplify_quote};
#[derive(Default)]
struct Dehtml {
strbuilder: String,
quote: String,
@@ -25,6 +26,9 @@ struct Dehtml {
/// Everything between `<div name="quote">` and `<div name="quoted-content">` is usually metadata
/// If this is > `0`, then we are inside a `<div name="quoted-content">`.
divs_since_quoted_content_div: u32,
/// `<div class="header-protection-legacy-display">` elements should be omitted, see
/// <https://www.rfc-editor.org/rfc/rfc9788.html#section-4.5.3.3>.
divs_since_hp_legacy_display: u32,
/// All-Inkl just puts the quote into `<blockquote> </blockquote>`. This count is
/// increased at each `<blockquote>` and decreased at each `</blockquote>`.
blockquotes_since_blockquote: u32,
@@ -48,20 +52,25 @@ impl Dehtml {
}
fn get_add_text(&self) -> AddText {
if self.divs_since_quote_div > 0 && self.divs_since_quoted_content_div == 0 {
AddText::No // Everything between `<div name="quoted">` and `<div name="quoted_content">` is metadata which we don't want
// Everything between `<div name="quoted">` and `<div name="quoted_content">` is
// metadata which we don't want.
if self.divs_since_quote_div > 0 && self.divs_since_quoted_content_div == 0
|| self.divs_since_hp_legacy_display > 0
{
AddText::No
} else {
self.add_text
}
}
}
#[derive(Debug, PartialEq, Clone, Copy)]
#[derive(Debug, Default, PartialEq, Clone, Copy)]
enum AddText {
/// Inside `<script>`, `<style>` and similar tags
/// which contents should not be displayed.
No,
#[default]
YesRemoveLineEnds,
/// Inside `<pre>`.
@@ -121,12 +130,7 @@ fn dehtml_quick_xml(buf: &str) -> (String, String) {
let mut dehtml = Dehtml {
strbuilder: String::with_capacity(buf.len()),
quote: String::new(),
add_text: AddText::YesRemoveLineEnds,
last_href: None,
divs_since_quote_div: 0,
divs_since_quoted_content_div: 0,
blockquotes_since_blockquote: 0,
..Default::default()
};
let mut reader = quick_xml::Reader::from_str(buf);
@@ -244,6 +248,7 @@ fn dehtml_endtag_cb(event: &BytesEnd, dehtml: &mut Dehtml) {
"div" => {
pop_tag(&mut dehtml.divs_since_quote_div);
pop_tag(&mut dehtml.divs_since_quoted_content_div);
pop_tag(&mut dehtml.divs_since_hp_legacy_display);
*dehtml.get_buf() += "\n\n";
dehtml.add_text = AddText::YesRemoveLineEnds;
@@ -295,6 +300,8 @@ fn dehtml_starttag_cb<B: std::io::BufRead>(
"div" => {
maybe_push_tag(event, reader, "quote", &mut dehtml.divs_since_quote_div);
maybe_push_tag(event, reader, "quoted-content", &mut dehtml.divs_since_quoted_content_div);
maybe_push_tag(event, reader, "header-protection-legacy-display",
&mut dehtml.divs_since_hp_legacy_display);
*dehtml.get_buf() += "\n\n";
dehtml.add_text = AddText::YesRemoveLineEnds;
@@ -539,6 +546,27 @@ mod tests {
assert_eq!(txt.text.trim(), "two\nlines");
}
#[test]
fn test_hp_legacy_display() {
let input = r#"
<html><head><title></title></head><body>
<div class="header-protection-legacy-display">
<pre>Subject: Dinner plans</pre>
</div>
<p>
Let's meet at Rama's Roti Shop at 8pm and go to the park
from there.
</p>
</body>
</html>
"#;
let txt = dehtml(input).unwrap();
assert_eq!(
txt.text.trim(),
"Let's meet at Rama's Roti Shop at 8pm and go to the park from there."
);
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn test_quote_div() {
let input = include_str!("../test-data/message/gmx-quote-body.eml");

6
src/mimefactory.rs
View File

@@ -1232,6 +1232,12 @@ impl MimeFactory {
// once new core versions are sufficiently deployed.
let anonymous_recipients = false;
if context.get_config_bool(Config::TestHooks).await? {
if let Some(hook) = &*context.pre_encrypt_mime_hook.lock() {
message = hook(context, message);
}
}
let encrypted = if let Some(shared_secret) = shared_secret {
encrypt_helper
.encrypt_symmetrically(context, &shared_secret, message, compress)

48
src/mimeparser.rs
View File

@@ -1323,6 +1323,10 @@ impl MimeMessage {
let is_html = mime_type == mime::TEXT_HTML;
if is_html {
self.is_mime_modified = true;
// NB: This unconditionally removes Legacy Display Elements (see
// <https://www.rfc-editor.org/rfc/rfc9788.html#section-4.5.3.3>). We
// don't check for the "hp-legacy-display" Content-Type parameter
// for simplicity.
if let Some(text) = dehtml(&decoded_data) {
text
} else {
@@ -1350,16 +1354,30 @@ impl MimeMessage {
let (simplified_txt, simplified_quote) = if mime_type.type_() == mime::TEXT
&& mime_type.subtype() == mime::PLAIN
&& is_format_flowed
{
let delsp = if let Some(delsp) = mail.ctype.params.get("delsp") {
delsp.as_str().eq_ignore_ascii_case("yes")
} else {
false
// Don't check that we're inside an encrypted or signed part for
// simplicity.
let simplified_txt = match mail
.ctype
.params
.get("hp-legacy-display")
.is_some_and(|v| v == "1")
{
false => simplified_txt,
true => rm_legacy_display_elements(&simplified_txt),
};
let unflowed_text = unformat_flowed(&simplified_txt, delsp);
let unflowed_quote = top_quote.map(|q| unformat_flowed(&q, delsp));
(unflowed_text, unflowed_quote)
if is_format_flowed {
let delsp = if let Some(delsp) = mail.ctype.params.get("delsp") {
delsp.as_str().eq_ignore_ascii_case("yes")
} else {
false
};
let unflowed_text = unformat_flowed(&simplified_txt, delsp);
let unflowed_quote = top_quote.map(|q| unformat_flowed(&q, delsp));
(unflowed_text, unflowed_quote)
} else {
(simplified_txt, top_quote)
}
} else {
(simplified_txt, top_quote)
};
@@ -1981,6 +1999,20 @@ impl MimeMessage {
}
}
fn rm_legacy_display_elements(text: &str) -> String {
let mut res = None;
for l in text.lines() {
res = res.map(|r: String| match r.is_empty() {
true => l.to_string(),
false => r + "\r\n" + l,
});
if l.is_empty() {
res = Some(String::new());
}
}
res.unwrap_or_default()
}
fn remove_header(
headers: &mut HashMap<String, String>,
key: &str,

33
src/mimeparser/mimeparser_tests.rs
View File

@@ -1751,6 +1751,39 @@ async fn test_time_in_future() -> Result<()> {
Ok(())
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn test_hp_legacy_display() -> Result<()> {
let mut tcm = TestContextManager::new();
let alice = &tcm.alice().await;
let bob = &tcm.bob().await;
let mut msg = Message::new_text(
"Subject: Dinner plans\n\
\n\
Let's eat"
.to_string(),
);
msg.set_subject("Dinner plans".to_string());
let chat_id = alice.create_chat(bob).await.id;
alice.set_config_bool(Config::TestHooks, true).await?;
*alice.pre_encrypt_mime_hook.lock() = Some(|_, mut mime| {
for (h, v) in &mut mime.headers {
if h == "Content-Type" {
if let mail_builder::headers::HeaderType::ContentType(ct) = v {
*ct = ct.clone().attribute("hp-legacy-display", "1");
}
}
}
mime
});
let sent_msg = alice.send_msg(chat_id, &mut msg).await;
let msg_bob = bob.recv_msg(&sent_msg).await;
assert_eq!(msg_bob.subject, "Dinner plans");
assert_eq!(msg_bob.text, "Let's eat");
Ok(())
}
/// Tests that subject is not prepended to the message
/// when bot receives it.
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]

1
src/test_utils.rs
View File

@@ -1679,7 +1679,6 @@ Until the false-positive is fixed:
}
}
#[cfg(test)]
mod tests {
use super::*;