Bishnu Dev Bishnu Dev - 3 months ago 15
Vb.net Question

Decrypt Data From DB Table Encrypted With CryptProtectData in VB.net

Hello i am trying to fetch data from a sqlite database table but the data is protected with CryptProtectData.

Can Someone tell me how do i decrypt the data?

Public Sub Name()
Dim ConnectionString As String = "Data Source=Employee.sqlite"
Dim SQLString As String = "SELECT dateofbirth From info"
Dim dt As DataTable = Nothing
Dim ds As New DataSet

Dim con As New SQLiteConnection(ConnectionString)
Dim cmd As New SQLiteCommand(SQLString, con)
con.Open()
Dim Reader As SQLite.SQLiteDataReader = cmd.ExecuteReader
While Reader.Read
Console.WriteLine(Reader("dateofbirth"))
End While

End Sub


in the above code, the field dateofbirth is encrypted.

Answer

Without knowing how your data is encoded and stored in the database I can only give a generic example, but hopefully this will get you started and/or point to different questions. This example assumes that the data stored in the database is a UTF8 encoded string.

Imports System.Security.Cryptography
'...
Dim Reader As SQLite.SQLiteDataReader = cmd.ExecuteReader
While Reader.Read
    ' Get data from BLOB column
    Dim encData As Byte() = DirectCast(rdr("dateofbirth"), Byte())
    ' Decrypt the data using DPAPI for the current user
    Dim outputData As Byte() = ProtectedData.Unprotect(encData, Nothing, DataProtectionScope.CurrentUser)
    ' Convert the decrypted data back to a string using UTF8 encoding
    Dim output As String = Encoding.UTF8.GetString(outputData)
    Console.WriteLine(output)
End While

You will need a reference to System.Security.dll and the import shown to find the ProtectedData class.