From 490a8d1b04f9f91e86b126a8da21de6e6cc047dd Mon Sep 17 00:00:00 2001
From: Tim Young <tim.young@lightsys.org>
Date: Wed, 9 Aug 2017 15:52:31 -0500
Subject: [PATCH] Throw a better error when we try and fail to load something.

---
 .../TrippleDESDocumentEncryption.cs           | 30 +++++++++++++++++--
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/EduNetworkBuilder/TrippleDESDocumentEncryption.cs b/EduNetworkBuilder/TrippleDESDocumentEncryption.cs
index 790a851..e0f02fb 100644
--- a/EduNetworkBuilder/TrippleDESDocumentEncryption.cs
+++ b/EduNetworkBuilder/TrippleDESDocumentEncryption.cs
@@ -128,10 +128,19 @@ namespace EduNetworkBuilder
             EncryptedXml exml = new EncryptedXml();
 
             // Decrypt the element using the symmetric key.
-            byte[] rgbOutput = exml.DecryptData(ed, algValue);
+            try
+            {
+                //Do the decryption
+                byte[] rgbOutput = exml.DecryptData(ed, algValue);
+                // Replace the encryptedData element with the plaintext XML elemnt.
+                exml.ReplaceData(encryptedElement, rgbOutput);
+            }
+            catch
+            {
+                //The decryption failed.
+                throw new LoginException("Key/Salt unable to decrypt.");
+            }
 
-            // Replace the encryptedData element with the plaintext XML elemnt.
-            exml.ReplaceData(encryptedElement, rgbOutput);
 
         }
 
@@ -186,4 +195,19 @@ namespace EduNetworkBuilder
         }
 
     }
+
+    /// <summary>
+    /// Create a simple login exception that we can throw when we try to decrypt and it fails
+    /// </summary>
+    public class LoginException : System.Exception
+    {
+        public LoginException() : base()
+        { }
+
+        public LoginException(String message) : base(message)
+        { }
+
+        public LoginException(String message, Exception innerException) : base(message, innerException)
+        { }
+    }
 }