feat: support receiving Autocrypt-Gossip with _verified attribute

This commit is a preparation for
sending Autocrypt-Gossip with `_verified` attribute
instead of `Chat-Verified` header.

src/mimeparser.rs

@@ -1,7 +1,7 @@
 //! # MIME message parsing module.
 
 use std::cmp::min;
-use std::collections::{HashMap, HashSet};
+use std::collections::{BTreeMap, HashMap, HashSet};
 use std::path::Path;
 use std::str;
 use std::str::FromStr;
@@ -36,6 +36,17 @@ use crate::tools::{
 };
 use crate::{chatlist_events, location, stock_str, 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
@@ -85,7 +96,7 @@ pub(crate) struct MimeMessage {
 
     /// The addresses for which there was a gossip header
     /// and their respective gossiped keys.
-    pub gossiped_keys: HashMap<String, SignedPublicKey>,
+    pub gossiped_keys: BTreeMap<String, GossipedKey>,
 
     /// Fingerprint of the key in the Autocrypt header.
     ///
@@ -1963,9 +1974,9 @@ async fn parse_gossip_headers(
     from: &str,
     recipients: &[SingleInfo],
     gossip_headers: Vec<String>,
-) -> Result<HashMap<String, SignedPublicKey>> {
+) -> Result<BTreeMap<String, GossipedKey>> {
     // XXX split the parsing from the modification part
-    let mut gossiped_keys: HashMap<String, SignedPublicKey> = Default::default();
+    let mut gossiped_keys: BTreeMap<String, GossipedKey> = Default::default();
 
     for value in &gossip_headers {
         let header = match value.parse::<Aheader>() {
@@ -2007,7 +2018,12 @@ async fn parse_gossip_headers(
             )
             .await?;
 
-        gossiped_keys.insert(header.addr.to_lowercase(), header.public_key);
+        let gossiped_key = GossipedKey {
+            public_key: header.public_key,
+
+            verified: header.verified,
+        };
+        gossiped_keys.insert(header.addr.to_lowercase(), gossiped_key);
     }
 
     Ok(gossiped_keys)