Tips On Brazilain Waxing

errors in a text file in encrypted form

always a good practice to keep a record of errors that occur in any application, I believe that the most common errors is to place a text file as a sort of log, or possibly within of a database to keep track. The more sophisticated there will make the information as an event of windows.

But if we want users of the application that are the curious, seeing and reading errors that occur in our application, a practical way is to encrypt the file. The problem with this is that if the text file becomes too large can slow the encryption application, and you have to open decrypt the file, post a message, and re-encrypt the file. Being

above a little impractical decided best to put the messages encrypted within the file. To modify the class which I am using to save your messages:

  1:     Public Shared Sub    WriteError (ByVal    errorMessage As String   ) 

  2: Try    

  3: Dim     path As String    =  "error.txt"  

     4:                  If   (  Not   File.Exists(System.Web.HttpContext.Current.Server.MapPath(path)))   Then   

      5:                    File.Create(System.Web.HttpContext.Current.Server.MapPath(path)).Close() 

      6:                  End     If   

      7:                Using w   As   StreamWriter = File.AppendText(System.Web.HttpContext.Current.Server.MapPath(path)) 

      8:                    w.WriteLine(Constants.vbCrLf &   "Error : "  ) 

      9:                  w.WriteLine ( "{0}" , DateTime.Now.ToString (CultureInfo.InvariantCulture)) 

  10:    Dim err As     String =  "In line:"  & System . Web.HttpContext.Current.Request.Url.ToString () & . "Message:" & errorMessage  

  11:  w.WriteLine (Encrypt (err,   True)) 

  12:  w.WriteLine ( "__________________________" ) 

  13:  w.Flush () 

  14:                   w.Close() 

     15:                  End   Using 

     16:              Catch   ex   As   Exception 

     17:                WriteError(ex.Message) 

     18:              End     Try   

     19:          End   Sub 
   
 
 

If you look at line 11 I put the word Encrypt, is there where I'm calling another function, the file imported into the library. NET Cryptography: Imports System.Security.Cryptography

 Public     Function Encrypt (ByVal   toEncrypt    As String , ByVal   useHashing    As Boolean )    As String Dim  

   keyArray  As    Byte () Dim 

   toEncryptArray  As    Byte () = UTF8Encoding. UTF8.GetBytes (toEncrypt) Dim 

     key   As     String   =   "MyKEY"   

           If   useHashing   Then   

               Dim   hashmd5   As     New   MD5CryptoServiceProvider() 

             keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key)) 

             hashmd5.Clear() 

           Else   

             keyArray = UTF8Encoding.UTF8.GetBytes(key) 

           End     If   

           Dim   tdes   As     New   TripleDESCryptoServiceProvider() 

        tdes.Key keyArray 

 tdes.Mode = = = CipherMode.ECB 

 tdes.Padding PaddingMode.PKCS7 

  Dim  ctransform  The  ICryptoTransform tdes.CreateEncryptor = () Dim 

   resultArray  The   GB  () = cTransform.TransformFinalBlock (toEncryptArray, 0, toEncryptArray.Length) 

 tdes.Clear () Return 

   Convert.ToBase64String (resultArray, 0, resultArray.Length) 

  End  function 

Now we have our encrypted messages. If we want to decrypt messages only have to use the following function somewhere and call it:

    Public Shared Function    Decrypt (ByVal   cipherString  As    String, ByVal   useHashing As     Boolean) As    String Dim  

   keyArray  As    Byte () Dim 

     toEncryptArray   As     Byte  () = Convert.FromBase64String(cipherString) 

           Dim   key   As     String   =   "MyKEY"   

           If   useHashing   Then   

               Dim   hashmd5   As     New   MD5CryptoServiceProvider() 

             keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key)) 

             hashmd5.Clear() 

           Else   

             keyArray = UTF8Encoding.UTF8.GetBytes(key) 

           End     If  

  Dim TDES   The New    TripleDESCryptoServiceProvider () 

 tdes.Key keyArray 

 tdes.Mode = = = CipherMode.ECB 

 tdes.Padding PaddingMode.PKCS7 

  Dim  ctransform  The  ICryptoTransform tdes.CreateDecryptor = () Dim 

   resultArray  The    Byte () = cTransform.TransformFinalBlock (toEncryptArray, 0, toEncryptArray.Length) 

 tdes.Clear () Return 

   UTF8Encoding.UTF8. GetString (resultArray) 

  End      Function   

} Maybe use an aspx form to receive the encrypted code:

  \u0026lt;% @ Page Language = "vb" AutoEventWireup = "false" CodeBehind = "WebForm1.aspx.vb" Inherits = "Bintech . WebForm1 "%>  

  \u0026lt;!   DOCTYPE html       PUBLIC "- / / W3C / / DTD XHTML 1.0 Transitional / / EN"   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd "     >   

   <    html     xmlns    ="http://www.w3.org/1999/xhtml"     >   

   <    head     runat    ="server"    >   

       <    title    >  Untitled Page  </    title    >   

   </    head    >   

   <    body    >    

       <    form     id    ="form1"     runat    ="server"    >   

       <    div    >   

         Forma de desencriptacion:  <    br     />   

           <    asp:TextBox     ID    ="TextBoxEncriptado"     runat    ="server"     Height    ="173px"     TextMode    ="MultiLine"     Width = "308px"  > \u0026lt;/   asp: TextBox  >  

  \u0026lt;    br />  

  \u0026lt;  asp: Button     ID = "Button1"  

    runat = "server" Text     = "Button"  >  

  \u0026lt;    br />  

  \u0026lt;  asp: Label      ID    ="LabelResult"     runat    ="server"    ></    asp:Label    ></    div    >   

       </    form    >   

   </    body    >   

   </    html    >   

and add an event to the button:

    Protected Sub Button1_Click  (  ByVal sender As   System.   Object, ByVal    and  As System.EventArgs) Handles   Button1.Click 

 LabelResult.Text = Decrypt (TextBoxEncriptado.Text,   False) End 

   Sub 

Ready!