Code to add mail to inbox

2 files changed, 148 insertions, 7 deletions

diff --git a/src/mail/incoming.rs b/src/mail/incoming.rs
index d87456f..86cbc07 100644
--- a/src/mail/incoming.rs
+++ b/src/mail/incoming.rs
@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::convert::TryFrom;
 use std::pin::Pin;
 use std::sync::{Arc, Weak};
 use std::time::Duration;
@@ -6,7 +7,10 @@ use std::time::Duration;
 use anyhow::{anyhow, bail, Result};
 use futures::{future::BoxFuture, Future, FutureExt};
 use k2v_client::{CausalValue, CausalityToken, K2vClient, K2vValue};
-use rusoto_s3::{PutObjectRequest, S3Client, S3};
+use rusoto_s3::{
+    GetObjectRequest, HeadObjectRequest, ListObjectsV2Request, PutObjectRequest, S3Client, S3,
+};
+use tokio::io::AsyncReadExt;
 use tokio::sync::watch;
 use tracing::{error, info, warn};
 
@@ -16,12 +20,15 @@ use crate::mail::mailbox::Mailbox;
 use crate::mail::uidindex::ImapUidvalidity;
 use crate::mail::unique_ident::*;
 use crate::mail::user::User;
+use crate::mail::IMF;
 use crate::time::now_msec;
 
 const INCOMING_PK: &str = "incoming";
 const INCOMING_LOCK_SK: &str = "lock";
 const INCOMING_WATCH_SK: &str = "watch";
 
+const MESSAGE_KEY: &str = "Message-Key";
+
 // When a lock is held, it is held for LOCK_DURATION (here 5 minutes)
 // It is renewed every LOCK_DURATION/3
 // If we are at 2*LOCK_DURATION/3 and haven't renewed, we assume we
@@ -113,10 +120,10 @@ async fn incoming_mail_watch_process_internal(
             }
         }
 
-        // If we were able to open INBOX, and we have mail (implies lock is held),
+        // If we were able to open INBOX, and we have mail,
         // fetch new mail
         if let (Some(inbox), Some(new_ct)) = (&inbox, new_mail) {
-            match handle_incoming_mail(&user, &s3, inbox).await {
+            match handle_incoming_mail(&user, &s3, inbox, &lock_held).await {
                 Ok(()) => {
                     prev_ct = Some(new_ct);
                 }
@@ -131,8 +138,84 @@ async fn incoming_mail_watch_process_internal(
     Ok(())
 }
 
-async fn handle_incoming_mail(user: &Arc<User>, s3: &S3Client, inbox: &Arc<Mailbox>) -> Result<()> {
-    unimplemented!()
+async fn handle_incoming_mail(
+    user: &Arc<User>,
+    s3: &S3Client,
+    inbox: &Arc<Mailbox>,
+    lock_held: &watch::Receiver<bool>,
+) -> Result<()> {
+    let mut lor = ListObjectsV2Request::default();
+    lor.bucket = user.creds.storage.bucket.clone();
+    lor.max_keys = Some(1000);
+    lor.prefix = Some("incoming/".into());
+    let mails_res = s3.list_objects_v2(lor).await?;
+
+    for object in mails_res.contents.unwrap_or_default() {
+        if !*lock_held.borrow() {
+            break;
+        }
+        if let Some(key) = object.key {
+            if let Some(mail_id) = key.strip_prefix("incoming/") {
+                if let Ok(mail_id) = mail_id.parse::<UniqueIdent>() {
+                    move_incoming_message(user, s3, inbox, mail_id).await?;
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+async fn move_incoming_message(
+    user: &Arc<User>,
+    s3: &S3Client,
+    inbox: &Arc<Mailbox>,
+    id: UniqueIdent,
+) -> Result<()> {
+    info!("Moving incoming message: {}", id);
+
+    let object_key = format!("incoming/{}", id);
+
+    // 1. Fetch message from S3
+    let mut gor = GetObjectRequest::default();
+    gor.bucket = user.creds.storage.bucket.clone();
+    gor.key = object_key.clone();
+    let get_result = s3.get_object(gor).await?;
+
+    // 1.a decrypt message key from headers
+    let key_encrypted_b64 = get_result
+        .metadata
+        .as_ref()
+        .ok_or(anyhow!("Missing key in metadata"))?
+        .get(MESSAGE_KEY)
+        .ok_or(anyhow!("Missing key in metadata"))?;
+    let key_encrypted = base64::decode(key_encrypted_b64)?;
+    let message_key = sodiumoxide::crypto::sealedbox::open(
+        &key_encrypted,
+        &user.creds.keys.public,
+        &user.creds.keys.secret,
+    )
+    .map_err(|_| anyhow!("Cannot decrypt message key"))?;
+    let message_key =
+        cryptoblob::Key::from_slice(&message_key).ok_or(anyhow!("Invalid message key"))?;
+
+    // 1.b retrieve message body
+    let obj_body = get_result.body.ok_or(anyhow!("Missing object body"))?;
+    let mut mail_buf = Vec::with_capacity(get_result.content_length.unwrap_or(128) as usize);
+    obj_body
+        .into_async_read()
+        .read_to_end(&mut mail_buf)
+        .await?;
+    let plain_mail = cryptoblob::open(&mail_buf, &message_key)
+        .map_err(|_| anyhow!("Cannot decrypt email content"))?;
+
+    // 2 parse mail and add to inbox
+    let msg = IMF::try_from(&plain_mail[..]).map_err(|_| anyhow!("Invalid email body"))?;
+    inbox
+        .append_from_s3(msg, id, &object_key, message_key)
+        .await?;
+
+    Ok(())
 }
 
 // ---- UTIL: K2V locking loop, use this to try to grab a lock using a K2V entry as a signal ----
@@ -307,7 +390,6 @@ async fn k2v_lock_loop_internal(
     if let Some(ct) = release {
         let _ = k2v.delete_item(pk, sk, ct.clone()).await;
     }
-
 }
 
 // ---- UTIL: function to wait for a value to have changed in K2V ----
@@ -372,7 +454,7 @@ impl EncryptedMessage {
         por.bucket = creds.storage.bucket.clone();
         por.key = format!("incoming/{}", gen_ident().to_string());
         por.metadata = Some(
-            [("Message-Key".to_string(), key_header)]
+            [(MESSAGE_KEY.to_string(), key_header)]
                 .into_iter()
                 .collect::<HashMap<_, _>>(),
         );
diff --git a/src/mail/mailbox.rs b/src/mail/mailbox.rs
index 35b681a..e63f712 100644
--- a/src/mail/mailbox.rs
+++ b/src/mail/mailbox.rs
@@ -98,6 +98,21 @@ impl Mailbox {
         self.mbox.write().await.append(msg, ident).await
     }
 
+    /// Insert an email into the mailbox, copying it from an existing S3 object
+    pub async fn append_from_s3<'a>(
+        &self,
+        msg: IMF<'a>,
+        ident: UniqueIdent,
+        s3_key: &str,
+        message_key: Key,
+    ) -> Result<()> {
+        self.mbox
+            .write()
+            .await
+            .append_from_s3(msg, ident, s3_key, message_key)
+            .await
+    }
+
     /// Delete a message definitively from the mailbox
     pub async fn delete<'a>(&self, id: UniqueIdent) -> Result<()> {
         self.mbox.write().await.delete(id).await
@@ -279,6 +294,50 @@ impl MailboxInternal {
         Ok(())
     }
 
+    async fn append_from_s3<'a>(
+        &mut self,
+        mail: IMF<'a>,
+        ident: UniqueIdent,
+        s3_key: &str,
+        message_key: Key,
+    ) -> Result<()> {
+        futures::try_join!(
+            async {
+                // Copy mail body from previous location
+                let mut cor = CopyObjectRequest::default();
+                cor.bucket = self.bucket.clone();
+                cor.key = format!("{}/{}", self.mail_path, ident);
+                cor.copy_source = format!("{}/{}", self.bucket, s3_key);
+                cor.metadata_directive = Some("REPLACE".into());
+                self.s3.copy_object(cor).await?;
+                Ok::<_, anyhow::Error>(())
+            },
+            async {
+                // Save mail meta
+                let meta = MailMeta {
+                    internaldate: now_msec(),
+                    headers: mail.raw[..mail.parsed.offset_body].to_vec(),
+                    message_key: message_key.clone(),
+                    rfc822_size: mail.raw.len(),
+                };
+                let meta_blob = seal_serialize(&meta, &self.encryption_key)?;
+                self.k2v
+                    .insert_item(&self.mail_path, &ident.to_string(), meta_blob, None)
+                    .await?;
+                Ok::<_, anyhow::Error>(())
+            }
+        )?;
+
+        // Add mail to Bayou mail index
+        let add_mail_op = self
+            .uid_index
+            .state()
+            .op_mail_add(ident, vec!["\\Unseen".into()]);
+        self.uid_index.push(add_mail_op).await?;
+
+        Ok(())
+    }
+
     async fn delete(&mut self, ident: UniqueIdent) -> Result<()> {
         if !self.uid_index.state().table.contains_key(&ident) {
             bail!("Cannot delete mail that doesn't exit");