Bishnu Dev Bishnu Dev - 1 year ago 74
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 Source

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.