How do I Iterate Through DataTable and Decrypt a field? - vb.net

Question

Good-day,
I need help with iterating through a DataTable (dbTable) and decrypting a particular field (ccNumber) before assigning its items to a Listview control (ListViewRecords).
I've already used the decryption code below elsewhere in my project on a Textbox with success, but can't figure out how to do it with the DataTable. Your assistance would be greatly appreciated, thanks.
HERE'S THE DECRYPTION CODE:
Dim DES As New System.Security.Cryptography.TripleDESCryptoServiceProvider
Dim Hash As New System.Security.Cryptography.MD5CryptoServiceProvider
Try
DES.Key = Hash.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(My.Settings.Key))
DES.Mode = System.Security.Cryptography.CipherMode.ECB
Dim DESDecrypter As System.Security.Cryptography.ICryptoTransform = DES.CreateDecryptor
Dim Buffer As Byte() = Convert.FromBase64String(TextBoxCard.Text)
TextBoxCard.Text = System.Text.ASCIIEncoding.ASCII.GetString(DESDecrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
Catch ex As Exception
MessageBox.Show("The following error(s) have occurred: " & ex.Message, Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
HERE'S THE CODE TO QUERY THE DB AND FILL THE LISTVIEW:
Private Sub loadRecords()
'FOR MySQL DATABASE USE
Dim dbConn As New MySqlConnection
Dim dbTable As New DataTable
Dim dbQuery As String = ""
Dim dbCmd As New MySqlCommand
Dim dbAdapter As New MySqlDataAdapter
dbTable.Clear()
Try
If dbConn.State = ConnectionState.Closed Then
dbConn.ConnectionString = String.Format("Server={0};Port={1};Uid={2};Password={3};Database=accounting", FormLogin.ComboBoxServerIP.SelectedItem, My.Settings.DB_Port, My.Settings.DB_UserID, My.Settings.DB_Password)
dbConn.Open()
End If
dbQuery = "SELECT *" & _
"FROM cc_master INNER JOIN customer ON customer.accountNumber = cc_master.customer_accountNumber " & _
"ORDER BY nameCOMPANY ASC"
With dbCmd
.CommandText = dbQuery
.Connection = dbConn
End With
With dbAdapter
.SelectCommand = dbCmd
.Fill(dbTable)
End With
ListViewRecords.Items.Clear()
For i = 0 To dbTable.Rows.Count - 1
With ListViewRecords
.Items.Add(dbTable.Rows(i)("ccID"))
With .Items(.Items.Count - 1).SubItems
.Add(dbTable.Rows(i)("nameCOMPANY"))
.Add(dbTable.Rows(i)("ccNumber"))
.Add(dbTable.Rows(i)("ccExpireMonth"))
.Add(dbTable.Rows(i)("ccExpireYear"))
.Add(dbTable.Rows(i)("ccType"))
.Add(dbTable.Rows(i)("ccAuthorizedUseStart"))
.Add(dbTable.Rows(i)("ccAuthorizedUseEnd"))
.Add(dbTable.Rows(i)("ccLocation"))
.Add(dbTable.Rows(i)("cardholderSalutation"))
.Add(dbTable.Rows(i)("cardholderLastname"))
.Add(dbTable.Rows(i)("cardholderFirstname"))
.Add(dbTable.Rows(i)("ccZipcode"))
End With
End With
Next
Catch ex As MySqlException
MessageBox.Show("A DATABASE ERROR HAS OCCURED" & vbCrLf & vbCrLf & ex.Message & vbCrLf & _
vbCrLf + "Please report this to the IT/Systems Helpdesk at Ext 131.")
End Try
dbConn.Close()
End Sub

Answer 1

Put the decryption thing in a function:
Function Decrypt(ByVal ToDecrypt) as String
Dim DES As New System.Security.Cryptography.TripleDESCryptoServiceProvider
Dim Hash As New System.Security.Cryptography.MD5CryptoServiceProvider
Try
DES.Key = Hash.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(My.Settings.Key))
DES.Mode = System.Security.Cryptography.CipherMode.ECB
Dim DESDecrypter As System.Security.Cryptography.ICryptoTransform = DES.CreateDecryptor
Dim Buffer As Byte() = Convert.FromBase64String(ToDecrypt)
return System.Text.ASCIIEncoding.ASCII.GetString(DESDecrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
Catch ex As Exception
return "Whatever failed message you want"
End Try
End Function
Then loop through your table like this and change the value:
for i as Integer = 0 to dbTable.Rows.Count - 1
dbTable.Rows(i)("ccNumber")) = Decrypt(dbTable.Rows(i)("ccNumber"))
This should work if I'm not totally off.