Encryption of email address in vb.net - vb.net

Question

I would like to know how I can encrypt an email address via vb.net code.
I found one sample which doesn't quite work with special characters and I am getting this error:
The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or a non-white space character among the padding characters.
Here is the code I am trying:
'The function used to encrypt the text
Private Function Encrypt(ByVal strText As String, ByVal strEncrKey _
As String) As String
Dim byKey() As Byte = {}
Dim IV() As Byte = {&H12, &H34, &H56, &H78, &H90, &HAB, &HCD, &HEF}
Try
byKey = System.Text.Encoding.UTF8.GetBytes(Left(strEncrKey, 8))
Dim des As New DESCryptoServiceProvider()
Dim inputByteArray() As Byte = Encoding.UTF8.GetBytes(strText)
Dim ms As New MemoryStream()
Dim cs As New CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write)
cs.Write(inputByteArray, 0, inputByteArray.Length)
cs.FlushFinalBlock()
Return Convert.ToBase64String(ms.ToArray())
Catch ex As Exception
Return ex.Message
End Try
End Function
What do you guys think? What am I doing wrong?
Thanks, Laziale
UPDATE: Full Stack trace:
System.FormatException was caught
Message=The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or a non-white space character among the padding characters.
Source=mscorlib
StackTrace:
at System.Convert.FromBase64String(String s)
at WEbsite.Login.Decrypt(String strText, String sDecrKey) in D:\Website\Account\Login.aspx.vb:line 213
InnerException:
UPDATE 2:
Encryption method added:
'The function used to decrypt the text
Private Function Decrypt(ByVal strText As String, ByVal sDecrKey _
As String) As String
Dim byKey() As Byte = {}
Dim IV() As Byte = {&H12, &H34, &H56, &H78, &H90, &HAB, &HCD, &HEF}
Dim inputByteArray(strText.Length) As Byte
Try
byKey = System.Text.Encoding.UTF8.GetBytes(Left(sDecrKey, 8))
Dim des As New DESCryptoServiceProvider()
inputByteArray = Convert.FromBase64String(strText)
Dim ms As New MemoryStream()
Dim cs As New CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write)
cs.Write(inputByteArray, 0, inputByteArray.Length)
cs.FlushFinalBlock()
Dim encoding As System.Text.Encoding = System.Text.Encoding.UTF8
Return encoding.GetString(ms.ToArray())
Catch ex As Exception
Return ex.Message
End Try
End Function

Answer 1

I have tried your Decrypt using, as input, the encrypted text and the same key.
It works as expected. The only change I have made to your code is the use of the Substring method instead of Left as in
byKey = System.Text.Encoding.UTF8.GetBytes(strDecrKey.Substring(0, 8))
I call the two methods in this way:
Dim result as String = Encrypt("test#gmail.com", "ABCD9876")
Dim decrypted = Decrypt(result, "ABCD9876")
I get back "test#gmail.com".
-Buon Weekend anche a te-

Answer 2

Use an String Builder instead of string as the parameter with the special characters.
Best regards.