From 1e598470efbf915f30815274db6d9d3150e39a21 Mon Sep 17 00:00:00 2001
From: Tim Young <tim.young@lightsys.org>
Date: Wed, 9 Aug 2017 16:34:42 -0500
Subject: [PATCH] Get the load func in place

---
 EduNetworkBuilder/PersonClass.cs | 68 ++++++++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 4 deletions(-)

diff --git a/EduNetworkBuilder/PersonClass.cs b/EduNetworkBuilder/PersonClass.cs
index 078a12b..88b11a7 100644
--- a/EduNetworkBuilder/PersonClass.cs
+++ b/EduNetworkBuilder/PersonClass.cs
@@ -88,14 +88,19 @@ namespace EduNetworkBuilder
 
         #region Load and Save 
         //Load and save functions
-        public void Load(string filename)
+        public bool Load(string filename, string password = "")
         {
             XmlDocument xmlDoc = new XmlDocument();
             if (File.Exists(filename))
             {
                 xmlDoc.Load(filename);
-                Load(xmlDoc);
+                if (TryToDecrypt(xmlDoc, password) != null)
+                {
+                    Load(xmlDoc);
+                    return true;
+                }
             }
+            return false;
         }
 
         public void Load(XmlNode TheNode)
@@ -263,9 +268,64 @@ namespace EduNetworkBuilder
             }
             return xmlTDES.Doc;
         }
-        #endregion
 
-        public bool AddHomework(SchoolworkClass ToAdd)
+        private XmlDocument TryToDecrypt(XmlDocument What, string PassToTry)
+        {
+            bool first_failed = false;
+            XmlElement inputElement = What.GetElementsByTagName("Salt")[0] as XmlElement;
+            if (inputElement == null) return What; //No salt means it was never encrypted.  Load as normal
+            string salt = inputElement.InnerText;
+            // Create a new TripleDES key. 
+            TripleDES tDESkey = TrippleDESDocumentEncryption.GenKey(PassToTry, salt);
+            TrippleDESDocumentEncryption xmlTDES = new TrippleDESDocumentEncryption(What, tDESkey);
+
+            //First, try to decrypt it using the user password.
+            try
+            {
+                xmlTDES.Decrypt("User");
+            }
+            catch (LoginException le)
+            {
+                //we ignore this.  Just try it again.
+                first_failed = true;
+            }
+            catch(Exception e) //This is bad.  Blow up and exit the function
+            {
+                MessageBox.Show(e.ToString());
+                return null;
+            }
+
+            if (first_failed)
+            {   //try a second one, decrypting the alt key and then using that.  The admin does this.
+                // Create a new instance of the TrippleDESDocumentEncryption object
+                // defined in this sample.
+                try
+                {
+                    xmlTDES.Decrypt("EncryptedKey");
+
+                    inputElement = xmlTDES.Doc.GetElementsByTagName("EncryptedKey")[0] as XmlElement;
+
+                    string userpw = inputElement.InnerText;
+                    xmlTDES.SetKey(userpw, salt);
+
+                    xmlTDES.Decrypt("User");
+                }
+                catch (LoginException le)
+                {
+                    //Neither password worked.  Exit out so we can prompt for an appropriate password
+                    return null;
+                }
+                catch (Exception e) //This is bad.  Blow up and exit the function
+                {
+                    MessageBox.Show(e.ToString());
+                    return null;
+                }
+            }
+            return xmlTDES.Doc;
+        }
+            #endregion
+
+            public bool AddHomework(SchoolworkClass ToAdd)
         {
             //Check to see if we already exist
             foreach(SchoolworkClass one in Projects)