view: error explanation string for failed SSL server cert verification

Author: abika

src/main/java/org/kontalk/misc/KonException.java

@@ -48,22 +48,20 @@ public enum Error {
     }
 
     private final Error mError;
-    private final Class<?> mExceptionClass;
 
     public KonException(Error error, Exception ex) {
-        super();
+        super(ex);
         mError = error;
-        mExceptionClass = ex.getClass();
     }
 
     public KonException(Error error) {
         super();
         mError = error;
-        mExceptionClass = this.getClass();
     }
 
-    public Class<?> getExceptionClass() {
-        return mExceptionClass;
+    public Class<?> getCauseClass() {
+        Throwable cause = this.getCause();
+        return cause == null ? this.getClass() : cause.getClass();
     }
 
     public Error getError() {

src/main/java/org/kontalk/view/Utils.java

@@ -268,10 +268,10 @@ static String getErrorText(KonException ex) {
                 break;
             case IMPORT_KEY:
                 errorText = Tr.tr("Can't create personal key from key files.") + " ";
-                if (ex.getExceptionClass().equals(IOException.class)) {
+                if (ex.getCauseClass().equals(IOException.class)) {
                     errorText += eol + Tr.tr("Is the public key file valid?");
                 }
-                if (ex.getExceptionClass().equals(CertificateException.class)) {
+                if (ex.getCauseClass().equals(CertificateException.class)) {
                     errorText += eol + Tr.tr("Are all key files valid?");
                 }
                 break;
@@ -299,19 +299,27 @@ static String getErrorText(KonException ex) {
                 break;
             case CLIENT_CONNECT:
                 errorText = Tr.tr("Can't connect to server.");
-                if (ex.getExceptionClass().equals(SmackException.ConnectionException.class)) {
+
+                if (ex.getCauseClass().equals(SmackException.ConnectionException.class)) {
                     errorText += eol + Tr.tr("Is the server address correct?");
-                }
-                if (ex.getExceptionClass().equals(SSLHandshakeException.class)) {
+                } else if (ex.getCauseClass().equals(SSLHandshakeException.class)) {
                     errorText += eol + Tr.tr("The server rejects the key.");
-                }
-                if (ex.getExceptionClass().equals(SmackException.NoResponseException.class)) {
+                } else if (ex.getCauseClass().equals(SmackException.NoResponseException.class)) {
                     errorText += eol + Tr.tr("The server does not respond.");
+                } else {
+                    Throwable cause = ex.getCause();
+                    if (cause != null) {
+                        Throwable causeCause = cause.getCause();
+                        if (causeCause != null &&
+                                causeCause.getClass().equals(SSLHandshakeException.class)) {
+                            errorText += eol + Tr.tr("The server certificate could not be validated.");
+                        }
+                    }
                 }
                 break;
             case CLIENT_LOGIN:
                 errorText = Tr.tr("Can't login to server.");
-                if (ex.getExceptionClass().equals(SASLErrorException.class)) {
+                if (ex.getCauseClass().equals(SASLErrorException.class)) {
                     errorText += eol + Tr.tr("The server rejects the account. Is the specified server correct and the account valid?");
                 }
                 break;