implement imape secure upgrade

Cargo.lock

@@ -93,7 +93,7 @@ dependencies = [
 [[package]]
 name = "async-imap"
 version = "0.2.0"
-source = "git+https://github.com/async-email/async-imap?branch=feat/send#be7b9cace12d0f323ef1e6e0a9fc698f4e26b64d"
+source = "git+https://github.com/async-email/async-imap?branch=feat/send#94a48158d6cc622aa0ed99d10b84088e9e53eb2f"
 dependencies = [
  "async-native-tls 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "async-std 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)",

src/imap/client.rs

@@ -120,21 +120,24 @@ impl Client {
 
     pub async fn secure<S: AsRef<str>>(
         self,
-        _domain: S,
-        _certificate_checks: CertificateChecks,
+        domain: S,
+        certificate_checks: CertificateChecks,
     ) -> ImapResult<Client> {
         if self.is_secure {
             Ok(self)
         } else {
-            unimplemented!()
-            // let Client { inner, .. } = self;
-            // let tls = dc_build_tls(certificate_checks);
-            // let client_sec = inner.secure(domain, tls).await?;
+            let Client { mut inner, .. } = self;
+            let tls = dc_build_tls(certificate_checks);
+            inner.run_command_and_check_ok("STARTTLS", None).await?;
 
-            // Ok(Client {
-            //     is_secure: true,
-            //     inner: client_sec,
-            // })
+            let stream = inner.into_inner();
+            let ssl_stream = tls.connect(domain.as_ref(), stream).await?;
+            let boxed: Box<dyn SessionStream> = Box::new(ssl_stream);
+
+            Ok(Client {
+                is_secure: true,
+                inner: ImapClient::new(boxed),
+            })
         }
     }
 }

src/imap/session.rs

@@ -14,6 +14,7 @@ pub(crate) trait SessionStream:
 {
 }
 
+impl SessionStream for TlsStream<Box<dyn SessionStream>> {}
 impl SessionStream for TlsStream<TcpStream> {}
 impl SessionStream for TcpStream {}