From f07374fa089e3a4041e3ac8871eb20cf42e53c05 Mon Sep 17 00:00:00 2001
From: M66B <M66B@users.noreply.github.com>
Date: Fri, 19 Jun 2020 18:35:42 +0200
Subject: [PATCH] Added protocol hint

---
 app/src/main/java/eu/faircode/email/EmailService.java | 11 +++++++++++
 app/src/main/res/values/strings.xml                   |  1 +
 2 files changed, 12 insertions(+)

diff --git a/app/src/main/java/eu/faircode/email/EmailService.java b/app/src/main/java/eu/faircode/email/EmailService.java
index ea6b27865c..c7c606c632 100644
--- a/app/src/main/java/eu/faircode/email/EmailService.java
+++ b/app/src/main/java/eu/faircode/email/EmailService.java
@@ -73,6 +73,8 @@ import javax.mail.event.StoreListener;
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLException;
+import javax.net.ssl.SSLHandshakeException;
 import javax.net.ssl.SSLSocket;
 import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.TrustManager;
@@ -369,6 +371,15 @@ public class EmailService implements AutoCloseable {
         } catch (MessagingException ex) {
             if (port == 995 && !("pop3".equals(protocol) || "pop3s".equals(protocol)))
                 throw new MessagingException(context.getString(R.string.title_service_port), ex);
+            else if (ex.getMessage() != null &&
+                    ex.getMessage().contains("Got bad greeting"))
+                throw new MessagingException(context.getString(R.string.title_service_protocol), ex);
+            else if (ex.getCause() instanceof SSLException &&
+                    ex.getCause().getMessage() != null &&
+                    ex.getCause().getMessage().contains("Unable to parse TLS packet header"))
+                throw new MessagingException(context.getString(R.string.title_service_protocol), ex);
+            else if (ex.getCause() instanceof SSLHandshakeException)
+                throw new MessagingException(context.getString(R.string.title_service_protocol), ex);
             else
                 throw ex;
         }
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0a8a6d0601..0768d59920 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -643,6 +643,7 @@
     <string name="title_hint_alias">Long press an identity to display options, like copy to create alias identities</string>
     <string name="title_service_vpn">This might be caused by the VPN that is being used</string>
     <string name="title_service_port">Please double check the port number</string>
+    <string name="title_service_protocol">Please double check the protocol (SSL/TLS or STARTTLS)</string>
 
     <string name="title_advanced_browse">Browse messages on the server</string>
     <string name="title_advanced_expand_read">Mark messages read on expanding</string>