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//! # MIME message parsing module.
use std::cmp::min;
use std::collections::{BTreeMap, HashMap, HashSet};
use std::path::Path;
use std::str;
use std::str::FromStr;
use anyhow::{Context as _, Result, bail, ensure};
use deltachat_contact_tools::{addr_cmp, addr_normalize, sanitize_bidi_characters};
use deltachat_derive::{FromSql, ToSql};
use format_flowed::unformat_flowed;
use mailparse::{DispositionType, MailHeader, MailHeaderMap, SingleInfo, addrparse_header};
use mime::Mime;
use crate::aheader::Aheader;
use crate::blob::BlobObject;
use crate::chat::{Chat, ChatId};
use crate::config::Config;
use crate::constants;
use crate::contact::{ContactId, import_public_key};
use crate::context::Context;
use crate::decrypt::{self, validate_detached_signature};
use crate::dehtml::dehtml;
use crate::download::PostMsgMetadata;
use crate::events::EventType;
use crate::headerdef::{HeaderDef, HeaderDefMap};
use crate::key::{self, DcKey, Fingerprint, SignedPublicKey};
use crate::log::warn;
use crate::message::{self, Message, MsgId, Viewtype, get_vcard_summary, set_msg_failed};
use crate::param::{Param, Params};
use crate::simplify::{SimplifiedText, simplify};
use crate::sync::SyncItems;
use crate::tools::{
get_filemeta, parse_receive_headers, smeared_time, time, truncate_msg_text, validate_id,
};
use crate::{chatlist_events, location, tools};
/// Public key extracted from `Autocrypt-Gossip`
/// header with associated information.
#[derive(Debug)]
pub struct GossipedKey {
/// Public key extracted from `keydata` attribute.
pub public_key: SignedPublicKey,
/// True if `Autocrypt-Gossip` has a `_verified` attribute.
pub verified: bool,
}
/// A parsed MIME message.
///
/// This represents the relevant information of a parsed MIME message
/// for deltachat. The original MIME message might have had more
/// information but this representation should contain everything
/// needed for deltachat's purposes.
///
/// It is created by parsing the raw data of an actual MIME message
/// using the [MimeMessage::from_bytes] constructor.
#[derive(Debug)]
pub(crate) struct MimeMessage {
/// Parsed MIME parts.
pub parts: Vec<Part>,
/// Message headers.
headers: HashMap<String, String>,
#[cfg(test)]
/// Names of removed (ignored) headers. Used by `header_exists()` needed for tests.
headers_removed: HashSet<String>,
/// List of addresses from the `To` and `Cc` headers.
///
/// Addresses are normalized and lowercase.
pub recipients: Vec<SingleInfo>,
/// List of addresses from the `Chat-Group-Past-Members` header.
pub past_members: Vec<SingleInfo>,
/// `From:` address.
pub from: SingleInfo,
/// Whether the message is incoming or outgoing (self-sent).
pub incoming: bool,
/// The List-Post address is only set for mailing lists. Users can send
/// messages to this address to post them to the list.
pub list_post: Option<String>,
pub chat_disposition_notification_to: Option<SingleInfo>,
/// Decryption error if decryption of the message has failed.
pub decryption_error: Option<String>,
/// Valid signature fingerprint if a message is an
/// Autocrypt encrypted and signed message and corresponding intended recipient fingerprints
/// (<https://www.rfc-editor.org/rfc/rfc9580.html#name-intended-recipient-fingerpr>) if any.
///
/// If a message is not encrypted or the signature is not valid,
/// this is `None`.
pub signature: Option<(Fingerprint, HashSet<Fingerprint>)>,
/// The addresses for which there was a gossip header
/// and their respective gossiped keys.
pub gossiped_keys: BTreeMap<String, GossipedKey>,
/// Fingerprint of the key in the Autocrypt header.
///
/// It is not verified that the sender can use this key.
pub autocrypt_fingerprint: Option<String>,
/// True if the message is a forwarded message.
pub is_forwarded: bool,
pub is_system_message: SystemMessage,
pub location_kml: Option<location::Kml>,
pub message_kml: Option<location::Kml>,
pub(crate) sync_items: Option<SyncItems>,
pub(crate) webxdc_status_update: Option<String>,
pub(crate) user_avatar: Option<AvatarAction>,
pub(crate) group_avatar: Option<AvatarAction>,
pub(crate) mdn_reports: Vec<Report>,
pub(crate) delivery_report: Option<DeliveryReport>,
/// Standard USENET signature, if any.
///
/// `None` means no text part was received, empty string means a text part without a footer is
/// received.
pub(crate) footer: Option<String>,
/// If set, this is a modified MIME message; clients should offer a way to view the original
/// MIME message in this case.
pub is_mime_modified: bool,
/// Decrypted raw MIME structure.
pub decoded_data: Vec<u8>,
/// Hop info for debugging.
pub(crate) hop_info: String,
/// Whether the message is auto-generated.
///
/// If chat message (with `Chat-Version` header) is auto-generated,
/// the contact sending this should be marked as bot.
///
/// If non-chat message is auto-generated,
/// it could be a holiday notice auto-reply,
/// in which case the message should be marked as bot-generated,
/// but the contact should not be.
pub(crate) is_bot: Option<bool>,
/// When the message was received, in secs since epoch.
pub(crate) timestamp_rcvd: i64,
/// Sender timestamp in secs since epoch. Allowed to be in the future due to unsynchronized
/// clocks, but not too much.
pub(crate) timestamp_sent: i64,
pub(crate) pre_message: PreMessageMode,
}
#[derive(Debug, Clone, PartialEq)]
pub(crate) enum PreMessageMode {
/// This is a post-message.
/// It replaces its pre-message attachment if it exists already,
/// and if the pre-message does not exist, it is treated as a normal message.
Post,
/// This is a Pre-Message,
/// it adds a message preview for a Post-Message
/// and it is ignored if the Post-Message was downloaded already
Pre {
post_msg_rfc724_mid: String,
metadata: Option<PostMsgMetadata>,
},
/// Atomic ("normal") message.
None,
}
#[derive(Debug, PartialEq)]
pub(crate) enum AvatarAction {
Delete,
Change(String),
}
/// System message type.
#[derive(
Debug, Default, Display, Clone, Copy, PartialEq, Eq, FromPrimitive, ToPrimitive, ToSql, FromSql,
)]
#[repr(u32)]
pub enum SystemMessage {
/// Unknown type of system message.
#[default]
Unknown = 0,
/// Group or broadcast channel name changed.
GroupNameChanged = 2,
/// Group or broadcast channel avatar changed.
GroupImageChanged = 3,
/// Member was added to the group.
MemberAddedToGroup = 4,
/// Member was removed from the group.
MemberRemovedFromGroup = 5,
/// Autocrypt Setup Message.
///
/// Deprecated as of 2026-03-15, such messages should not be created
/// but may exist in the database.
AutocryptSetupMessage = 6,
/// Secure-join message.
SecurejoinMessage = 7,
/// Location streaming is enabled.
LocationStreamingEnabled = 8,
/// Location-only message.
LocationOnly = 9,
/// Chat ephemeral message timer is changed.
EphemeralTimerChanged = 10,
/// "Messages are end-to-end encrypted."
ChatProtectionEnabled = 11,
/// "%1$s sent a message from another device.", deprecated 2025-07
ChatProtectionDisabled = 12,
/// Message can't be sent because of `Invalid unencrypted mail to <>`
/// which is sent by chatmail servers.
InvalidUnencryptedMail = 13,
/// 1:1 chats info message telling that SecureJoin has started and the user should wait for it
/// to complete.
SecurejoinWait = 14,
/// 1:1 chats info message telling that SecureJoin is still running, but the user may already
/// send messages.
SecurejoinWaitTimeout = 15,
/// Self-sent-message that contains only json used for multi-device-sync;
/// if possible, we attach that to other messages as for locations.
MultiDeviceSync = 20,
/// Sync message that contains a json payload
/// sent to the other webxdc instances
/// These messages are not shown in the chat.
WebxdcStatusUpdate = 30,
/// Webxdc info added with `info` set in `send_webxdc_status_update()`.
WebxdcInfoMessage = 32,
/// This message contains a users iroh node address.
IrohNodeAddr = 40,
/// "Messages are end-to-end encrypted."
ChatE2ee = 50,
/// Message indicating that a call was accepted.
CallAccepted = 66,
/// Message indicating that a call was ended.
CallEnded = 67,
/// Group or broadcast channel description changed.
GroupDescriptionChanged = 70,
}
impl MimeMessage {
/// Parse a mime message.
///
/// This method has some side-effects,
/// such as saving blobs and saving found public keys to the database.
pub(crate) async fn from_bytes(context: &Context, body: &[u8]) -> Result<Self> {
let mail = mailparse::parse_mail(body)?;
let timestamp_rcvd = smeared_time(context);
let mut timestamp_sent =
Self::get_timestamp_sent(&mail.headers, timestamp_rcvd, timestamp_rcvd);
let hop_info = parse_receive_headers(&mail.get_headers());
let mut headers = Default::default();
let mut headers_removed = HashSet::<String>::new();
let mut recipients = Default::default();
let mut past_members = Default::default();
let mut from = Default::default();
let mut list_post = Default::default();
let mut chat_disposition_notification_to = None;
// Parse IMF headers.
MimeMessage::merge_headers(
context,
&mut headers,
&mut headers_removed,
&mut recipients,
&mut past_members,
&mut from,
&mut list_post,
&mut chat_disposition_notification_to,
&mail,
);
headers_removed.extend(
headers
.extract_if(|k, _v| is_hidden(k))
.map(|(k, _v)| k.to_string()),
);
// Parse hidden headers.
let mimetype = mail.ctype.mimetype.parse::<Mime>()?;
let (part, mimetype) =
if mimetype.type_() == mime::MULTIPART && mimetype.subtype().as_str() == "signed" {
if let Some(part) = mail.subparts.first() {
// We don't remove "subject" from `headers` because currently just signed
// messages are shown as unencrypted anyway.
timestamp_sent =
Self::get_timestamp_sent(&part.headers, timestamp_sent, timestamp_rcvd);
MimeMessage::merge_headers(
context,
&mut headers,
&mut headers_removed,
&mut recipients,
&mut past_members,
&mut from,
&mut list_post,
&mut chat_disposition_notification_to,
part,
);
(part, part.ctype.mimetype.parse::<Mime>()?)
} else {
// Not a valid signed message, handle it as plaintext.
(&mail, mimetype)
}
} else {
// Currently we do not sign unencrypted messages by default.
(&mail, mimetype)
};
if mimetype.type_() == mime::MULTIPART
&& mimetype.subtype().as_str() == "mixed"
&& let Some(part) = part.subparts.first()
{
for field in &part.headers {
let key = field.get_key().to_lowercase();
if !headers.contains_key(&key) && is_hidden(&key) || key == "message-id" {
headers.insert(key.to_string(), field.get_value());
}
}
}
// Overwrite Message-ID with X-Microsoft-Original-Message-ID.
// However if we later find Message-ID in the protected part,
// it will overwrite both.
if let Some(microsoft_message_id) = remove_header(
&mut headers,
HeaderDef::XMicrosoftOriginalMessageId.get_headername(),
&mut headers_removed,
) {
headers.insert(
HeaderDef::MessageId.get_headername().to_string(),
microsoft_message_id,
);
}
// Remove headers that are allowed _only_ in the encrypted+signed part. It's ok to leave
// them in signed-only emails, but has no value currently.
let encrypted = false;
Self::remove_secured_headers(&mut headers, &mut headers_removed, encrypted);
let mut from = from.context("No from in message")?;
let mut gossiped_keys = Default::default();
let from_is_not_self_addr = !context.is_self_addr(&from.addr).await?;
let mut aheader_values = mail.headers.get_all_values(HeaderDef::Autocrypt.into());
let mut pre_message = if mail
.headers
.get_header_value(HeaderDef::ChatIsPostMessage)
.is_some()
{
PreMessageMode::Post
} else {
PreMessageMode::None
};
let mail_raw; // Memory location for a possible decrypted message.
let decrypted_msg; // Decrypted signed OpenPGP message.
let expected_sender_fingerprint: Option<String>;
let (mail, is_encrypted) = match decrypt::decrypt(context, &mail).await {
Ok(Some((mut msg, expected_sender_fp))) => {
mail_raw = msg.as_data_vec().unwrap_or_default();
let decrypted_mail = mailparse::parse_mail(&mail_raw)?;
if std::env::var(crate::DCC_MIME_DEBUG).is_ok() {
info!(
context,
"decrypted message mime-body:\n{}",
String::from_utf8_lossy(&mail_raw),
);
}
decrypted_msg = Some(msg);
timestamp_sent = Self::get_timestamp_sent(
&decrypted_mail.headers,
timestamp_sent,
timestamp_rcvd,
);
let protected_aheader_values = decrypted_mail
.headers
.get_all_values(HeaderDef::Autocrypt.into());
if !protected_aheader_values.is_empty() {
aheader_values = protected_aheader_values;
}
expected_sender_fingerprint = expected_sender_fp;
(Ok(decrypted_mail), true)
}
Ok(None) => {
mail_raw = Vec::new();
decrypted_msg = None;
expected_sender_fingerprint = None;
(Ok(mail), false)
}
Err(err) => {
mail_raw = Vec::new();
decrypted_msg = None;
expected_sender_fingerprint = None;
warn!(context, "decryption failed: {:#}", err);
(Err(err), false)
}
};
let mut autocrypt_header = None;
if from_is_not_self_addr {
// See `get_all_addresses_from_header()` for why we take the last valid header.
for val in aheader_values.iter().rev() {
autocrypt_header = match Aheader::from_str(val) {
Ok(header) if addr_cmp(&header.addr, &from.addr) => Some(header),
Ok(header) => {
warn!(
context,
"Autocrypt header address {:?} is not {:?}.", header.addr, from.addr
);
continue;
}
Err(err) => {
warn!(context, "Failed to parse Autocrypt header: {:#}.", err);
continue;
}
};
break;
}
}
let autocrypt_fingerprint = if let Some(autocrypt_header) = &autocrypt_header {
let fingerprint = autocrypt_header.public_key.dc_fingerprint().hex();
import_public_key(context, &autocrypt_header.public_key)
.await
.context("Failed to import public key from the Autocrypt header")?;
Some(fingerprint)
} else {
None
};
let mut public_keyring = if from_is_not_self_addr {
if let Some(autocrypt_header) = autocrypt_header {
vec![autocrypt_header.public_key]
} else {
vec![]
}
} else {
key::load_self_public_keyring(context).await?
};
if let Some(signature) = match &decrypted_msg {
Some(pgp::composed::Message::Literal { .. }) => None,
Some(pgp::composed::Message::Compressed { .. }) => {
// One layer of compression should already be handled by now.
// We don't decompress messages compressed multiple times.
None
}
Some(pgp::composed::Message::Signed { reader, .. }) => reader.signature(0),
Some(pgp::composed::Message::Encrypted { .. }) => {
// The message is already decrypted once.
None
}
None => None,
} {
for issuer_fingerprint in signature.issuer_fingerprint() {
let issuer_fingerprint =
crate::key::Fingerprint::from(issuer_fingerprint.clone()).hex();
if let Some(public_key_bytes) = context
.sql
.query_row_optional(
"SELECT public_key
FROM public_keys
WHERE fingerprint=?",
(&issuer_fingerprint,),
|row| {
let bytes: Vec<u8> = row.get(0)?;
Ok(bytes)
},
)
.await?
{
let public_key = SignedPublicKey::from_slice(&public_key_bytes)?;
public_keyring.push(public_key)
}
}
}
let mut signatures = if let Some(ref decrypted_msg) = decrypted_msg {
crate::pgp::valid_signature_fingerprints(decrypted_msg, &public_keyring)
} else {
HashMap::new()
};
let mail = mail.as_ref().map(|mail| {
let (content, signatures_detached) = validate_detached_signature(mail, &public_keyring)
.unwrap_or((mail, Default::default()));
let signatures_detached = signatures_detached
.into_iter()
.map(|fp| (fp, Vec::new()))
.collect::<HashMap<_, _>>();
signatures.extend(signatures_detached);
content
});
if let Some(expected_sender_fingerprint) = expected_sender_fingerprint {
ensure!(
!signatures.is_empty(),
"Unsigned message is not allowed to be encrypted with this shared secret"
);
ensure!(
signatures.len() == 1,
"Too many signatures on symm-encrypted message"
);
ensure!(
signatures.contains_key(&expected_sender_fingerprint.parse()?),
"This sender is not allowed to encrypt with this secret key"
);
}
if let (Ok(mail), true) = (mail, is_encrypted) {
if !signatures.is_empty() {
// Unsigned "Subject" mustn't be prepended to messages shown as encrypted
// (<https://github.com/deltachat/deltachat-core-rust/issues/1790>).
// Other headers are removed by `MimeMessage::merge_headers()` except for "List-ID".
remove_header(&mut headers, "subject", &mut headers_removed);
remove_header(&mut headers, "list-id", &mut headers_removed);
}
// let known protected headers from the decrypted
// part override the unencrypted top-level
// Signature was checked for original From, so we
// do not allow overriding it.
let mut inner_from = None;
MimeMessage::merge_headers(
context,
&mut headers,
&mut headers_removed,
&mut recipients,
&mut past_members,
&mut inner_from,
&mut list_post,
&mut chat_disposition_notification_to,
mail,
);
if !signatures.is_empty() {
// Handle any gossip headers if the mail was encrypted. See section
// "3.6 Key Gossip" of <https://autocrypt.org/autocrypt-spec-1.1.0.pdf>
// but only if the mail was correctly signed. Probably it's ok to not require
// encryption here, but let's follow the standard.
let gossip_headers = mail.headers.get_all_values("Autocrypt-Gossip");
gossiped_keys =
parse_gossip_headers(context, &from.addr, &recipients, gossip_headers).await?;
}
if let Some(inner_from) = inner_from {
if !addr_cmp(&inner_from.addr, &from.addr) {
// There is a From: header in the encrypted
// part, but it doesn't match the outer one.
// This _might_ be because the sender's mail server
// replaced the sending address, e.g. in a mailing list.
// Or it's because someone is doing some replay attack.
// Resending encrypted messages via mailing lists
// without reencrypting is not useful anyway,
// so we return an error below.
warn!(
context,
"From header in encrypted part doesn't match the outer one",
);
// Return an error from the parser.
// This will result in creating a tombstone
// and no further message processing
// as if the MIME structure is broken.
bail!("From header is forged");
}
from = inner_from;
}
}
if signatures.is_empty() {
Self::remove_secured_headers(&mut headers, &mut headers_removed, is_encrypted);
}
if !is_encrypted {
signatures.clear();
}
if let (Ok(mail), true) = (mail, is_encrypted)
&& let Some(post_msg_rfc724_mid) =
mail.headers.get_header_value(HeaderDef::ChatPostMessageId)
{
let post_msg_rfc724_mid = parse_message_id(&post_msg_rfc724_mid)?;
let metadata = if let Some(value) = mail
.headers
.get_header_value(HeaderDef::ChatPostMessageMetadata)
{
match PostMsgMetadata::try_from_header_value(&value) {
Ok(metadata) => Some(metadata),
Err(error) => {
error!(
context,
"Failed to parse metadata header in pre-message for {post_msg_rfc724_mid}: {error:#}."
);
None
}
}
} else {
warn!(
context,
"Expected pre-message for {post_msg_rfc724_mid} to have metadata header."
);
None
};
pre_message = PreMessageMode::Pre {
post_msg_rfc724_mid,
metadata,
};
}
let signature = signatures
.into_iter()
.last()
.map(|(fp, recipient_fps)| (fp, recipient_fps.into_iter().collect::<HashSet<_>>()));
let incoming = if let Some((ref sig_fp, _)) = signature {
sig_fp.hex() != key::self_fingerprint(context).await?
} else {
// rare case of getting a cleartext message
// so we determine 'incoming' flag by From-address
from_is_not_self_addr
};
let mut parser = MimeMessage {
parts: Vec::new(),
headers,
#[cfg(test)]
headers_removed,
recipients,
past_members,
list_post,
from,
incoming,
chat_disposition_notification_to,
decryption_error: mail.err().map(|err| format!("{err:#}")),
// only non-empty if it was a valid autocrypt message
signature,
autocrypt_fingerprint,
gossiped_keys,
is_forwarded: false,
mdn_reports: Vec::new(),
is_system_message: SystemMessage::Unknown,
location_kml: None,
message_kml: None,
sync_items: None,
webxdc_status_update: None,
user_avatar: None,
group_avatar: None,
delivery_report: None,
footer: None,
is_mime_modified: false,
decoded_data: Vec::new(),
hop_info,
is_bot: None,
timestamp_rcvd,
timestamp_sent,
pre_message,
};
match mail {
Ok(mail) => {
parser.parse_mime_recursive(context, mail, false).await?;
}
Err(err) => {
let txt = "[This message cannot be decrypted.\n\n• It might already help to simply reply to this message and ask the sender to send the message again.\n\n• If you just re-installed Delta Chat then it is best if you re-setup Delta Chat now and choose \"Add as second device\" or import a backup.]";
let part = Part {
typ: Viewtype::Text,
msg_raw: Some(txt.to_string()),
msg: txt.to_string(),
// Don't change the error prefix for now,
// receive_imf.rs:lookup_chat_by_reply() checks it.
error: Some(format!("Decrypting failed: {err:#}")),
..Default::default()
};
parser.do_add_single_part(part);
}
};
let is_location_only = parser.location_kml.is_some() && parser.parts.is_empty();
if parser.mdn_reports.is_empty()
&& !is_location_only
&& parser.sync_items.is_none()
&& parser.webxdc_status_update.is_none()
{
let is_bot =
parser.headers.get("auto-submitted") == Some(&"auto-generated".to_string());
parser.is_bot = Some(is_bot);
}
parser.maybe_remove_bad_parts();
parser.maybe_remove_inline_mailinglist_footer();
parser.heuristically_parse_ndn(context).await;
parser.parse_headers(context).await?;
parser.decoded_data = mail_raw;
Ok(parser)
}
#[expect(clippy::arithmetic_side_effects)]
fn get_timestamp_sent(
hdrs: &[mailparse::MailHeader<'_>],
default: i64,
timestamp_rcvd: i64,
) -> i64 {
hdrs.get_header_value(HeaderDef::Date)
.and_then(|v| mailparse::dateparse(&v).ok())
.map_or(default, |value| {
min(value, timestamp_rcvd + constants::TIMESTAMP_SENT_TOLERANCE)
})
}
/// Parses system messages.
fn parse_system_message_headers(&mut self) {
if let Some(value) = self.get_header(HeaderDef::ChatContent) {
if value == "location-streaming-enabled" {
self.is_system_message = SystemMessage::LocationStreamingEnabled;
} else if value == "ephemeral-timer-changed" {
self.is_system_message = SystemMessage::EphemeralTimerChanged;
} else if value == "protection-enabled" {
self.is_system_message = SystemMessage::ChatProtectionEnabled;
} else if value == "protection-disabled" {
self.is_system_message = SystemMessage::ChatProtectionDisabled;
} else if value == "group-avatar-changed" {
self.is_system_message = SystemMessage::GroupImageChanged;
} else if value == "call-accepted" {
self.is_system_message = SystemMessage::CallAccepted;
} else if value == "call-ended" {
self.is_system_message = SystemMessage::CallEnded;
}
} else if self.get_header(HeaderDef::ChatGroupMemberRemoved).is_some() {
self.is_system_message = SystemMessage::MemberRemovedFromGroup;
} else if self.get_header(HeaderDef::ChatGroupMemberAdded).is_some() {
self.is_system_message = SystemMessage::MemberAddedToGroup;
} else if self.get_header(HeaderDef::ChatGroupNameChanged).is_some() {
self.is_system_message = SystemMessage::GroupNameChanged;
} else if self
.get_header(HeaderDef::ChatGroupDescriptionChanged)
.is_some()
{
self.is_system_message = SystemMessage::GroupDescriptionChanged;
}
}
/// Parses avatar action headers.
fn parse_avatar_headers(&mut self, context: &Context) -> Result<()> {
if let Some(header_value) = self.get_header(HeaderDef::ChatGroupAvatar) {
self.group_avatar =
self.avatar_action_from_header(context, header_value.to_string())?;
}
if let Some(header_value) = self.get_header(HeaderDef::ChatUserAvatar) {
self.user_avatar = self.avatar_action_from_header(context, header_value.to_string())?;
}
Ok(())
}
fn parse_videochat_headers(&mut self) {
let content = self
.get_header(HeaderDef::ChatContent)
.unwrap_or_default()
.to_string();
let room = self
.get_header(HeaderDef::ChatWebrtcRoom)
.map(|s| s.to_string());
let accepted = self
.get_header(HeaderDef::ChatWebrtcAccepted)
.map(|s| s.to_string());
let has_video = self
.get_header(HeaderDef::ChatWebrtcHasVideoInitially)
.map(|s| s.to_string());
if let Some(part) = self.parts.first_mut() {
if let Some(room) = room {
if content == "call" {
part.typ = Viewtype::Call;
part.param.set(Param::WebrtcRoom, room);
}
} else if let Some(accepted) = accepted {
part.param.set(Param::WebrtcAccepted, accepted);
}
if let Some(has_video) = has_video {
part.param.set(Param::WebrtcHasVideoInitially, has_video);
}
}
}
/// Squashes mutitpart chat messages with attachment into single-part messages.
///
/// Delta Chat sends attachments, such as images, in two-part messages, with the first message
/// containing a description. If such a message is detected, text from the first part can be
/// moved to the second part, and the first part dropped.
fn squash_attachment_parts(&mut self) {
if self.parts.len() == 2
&& self.parts.first().map(|textpart| textpart.typ) == Some(Viewtype::Text)
&& self
.parts
.get(1)
.is_some_and(|filepart| match filepart.typ {
Viewtype::Image
| Viewtype::Gif
| Viewtype::Sticker
| Viewtype::Audio
| Viewtype::Voice
| Viewtype::Video
| Viewtype::Vcard
| Viewtype::File
| Viewtype::Webxdc => true,
Viewtype::Unknown | Viewtype::Text | Viewtype::Call => false,
})
{
let mut parts = std::mem::take(&mut self.parts);
let Some(mut filepart) = parts.pop() else {
// Should never happen.
return;
};
let Some(textpart) = parts.pop() else {
// Should never happen.
return;
};
filepart.msg.clone_from(&textpart.msg);
if let Some(quote) = textpart.param.get(Param::Quote) {
filepart.param.set(Param::Quote, quote);
}
self.parts = vec![filepart];
}
}
/// Processes chat messages with attachments.
fn parse_attachments(&mut self) {
// Attachment messages should be squashed into a single part
// before calling this function.
if self.parts.len() != 1 {
return;
}
if let Some(mut part) = self.parts.pop() {
if part.typ == Viewtype::Audio && self.get_header(HeaderDef::ChatVoiceMessage).is_some()
{
part.typ = Viewtype::Voice;
}
if (part.typ == Viewtype::Image || part.typ == Viewtype::Gif)
&& let Some(value) = self.get_header(HeaderDef::ChatContent)
&& value == "sticker"
{
part.typ = Viewtype::Sticker;
}
if (part.typ == Viewtype::Audio
|| part.typ == Viewtype::Voice
|| part.typ == Viewtype::Video)
&& let Some(field_0) = self.get_header(HeaderDef::ChatDuration)
{
let duration_ms = field_0.parse().unwrap_or_default();
if duration_ms > 0 && duration_ms < 24 * 60 * 60 * 1000 {
part.param.set_int(Param::Duration, duration_ms);
}
}
self.parts.push(part);
}
}
async fn parse_headers(&mut self, context: &Context) -> Result<()> {
self.parse_system_message_headers();
self.parse_avatar_headers(context)?;
self.parse_videochat_headers();
if self.delivery_report.is_none() {
self.squash_attachment_parts();
}
if !context.get_config_bool(Config::Bot).await?
&& let Some(ref subject) = self.get_subject()
{
let mut prepend_subject = true;
if self.decryption_error.is_none() {
let colon = subject.find(':');
if colon == Some(2)
|| colon == Some(3)
|| self.has_chat_version()
|| subject.contains("Chat:")
{
prepend_subject = false
}
}
// For mailing lists, always add the subject because sometimes there are different topics
// and otherwise it might be hard to keep track:
if self.is_mailinglist_message() && !self.has_chat_version() {
prepend_subject = true;
}
if prepend_subject && !subject.is_empty() {
let part_with_text = self
.parts
.iter_mut()
.find(|part| !part.msg.is_empty() && !part.is_reaction);
if let Some(part) = part_with_text {
// Message bubbles are small, so we use en dash to save space. In some
// languages there may be em dashes in the message text added by the author,
// they may look stronger than Subject separation, this is a known thing.
// Anyway, classic email support isn't a priority as of 2025.
part.msg = format!("{} – {}", subject, part.msg);
}
}
}
if self.is_forwarded {
for part in &mut self.parts {
part.param.set_int(Param::Forwarded, 1);
}
}
self.parse_attachments();
// See if an MDN is requested from the other side
let mut wants_mdn = false;
if self.decryption_error.is_none()
&& (!self.parts.is_empty() || matches!(&self.pre_message, PreMessageMode::Pre { .. }))
&& let Some(ref dn_to) = self.chat_disposition_notification_to
{
// Check that the message is not outgoing.
let from = &self.from.addr;
if !context.is_self_addr(from).await? {
if from.to_lowercase() == dn_to.addr.to_lowercase() {
wants_mdn = true;
if let Some(part) = self.parts.last_mut() {
part.param.set_int(Param::WantsMdn, 1);
}
} else {
warn!(
context,
"{} requested a read receipt to {}, ignoring", from, dn_to.addr
);
}
}
}
// If there were no parts, especially a non-DC mail user may
// just have send a message in the subject with an empty body.
// Besides, we want to show something in case our incoming-processing
// failed to properly handle an incoming message.
if self.parts.is_empty() && self.mdn_reports.is_empty() {
let mut part = Part {
typ: Viewtype::Text,
..Default::default()
};
if wants_mdn {
part.param.set_int(Param::WantsMdn, 1);
}
if let Some(ref subject) = self.get_subject()
&& !self.has_chat_version()
&& self.webxdc_status_update.is_none()
{
part.msg = subject.to_string();
}
self.do_add_single_part(part);
}
if self.is_bot == Some(true) {
for part in &mut self.parts {
part.param.set(Param::Bot, "1");