From 3b1dded8c2fc232e2de999af50d35d428a2054c2 Mon Sep 17 00:00:00 2001
From: M66B <M66B@users.noreply.github.com>
Date: Thu, 19 Dec 2019 17:15:29 +0100
Subject: [PATCH] Show subject DN

---
 app/src/main/java/eu/faircode/email/MailService.java | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/eu/faircode/email/MailService.java b/app/src/main/java/eu/faircode/email/MailService.java
index db5e84ebe9..6af243e257 100644
--- a/app/src/main/java/eu/faircode/email/MailService.java
+++ b/app/src/main/java/eu/faircode/email/MailService.java
@@ -26,6 +26,7 @@ import java.net.UnknownHostException;
 import java.security.GeneralSecurityException;
 import java.security.KeyStore;
 import java.security.NoSuchAlgorithmException;
+import java.security.Principal;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateParsingException;
@@ -491,7 +492,15 @@ public class MailService implements AutoCloseable {
                             }
 
                             // Check certificates
-                            rtm.checkServerTrusted(chain, authType);
+                            try {
+                                rtm.checkServerTrusted(chain, authType);
+                            } catch (CertificateException ex) {
+                                Principal principal = certificate.getSubjectDN();
+                                if (principal == null)
+                                    throw ex;
+                                else
+                                    throw new CertificateException(principal.getName(), ex);
+                            }
 
                             // Check host name
                             List<String> names = getDnsNames(certificate);