Encrypt column data in SSIS

Case
I want to encrypt a column with sensitive data. How do I do that in SSIS?

Solutions
A) If your source is a SQL Server table, you could use T-SQL to encrypt your data.
B) An other option is the Script Component with some .Net coding to encrypt your sensitive data.

Note: see this post for encrypting a whole file instead of certain columns.

Let's elaborate that Script Component solution. Let's assume you have an user table that you want to export to a csv file, but you don't want to export the password (or salary) column in plaintext.

Usertable in SQL Server

1) Variable
Create a string variable named EncryptionKey to store your encryption key in and give it a value.

Rightclick in the Control Flow

2) Data Flow Task
Create a new Data Flow Task with a source connection to your table. This example has two columns: Name and Password (see screenshot above step 1).

Data Flow Task with source

3) Script Component
Add a Script Component after the source and choose Transformation. Connect it to the source and give it a suitable name.

Script Component Type Transformation

4) Select Variable
Edit the Script Component and select the variable EncryptionKey from step 1 as a ReadOnlyVariable.

ReadOnlyVariables

5) Input Column
Go to the Input Columns section and select the column that you want to encrypt as a ReadOnly input column.

Readonly input column

6) Output Column
Go to the Inputs and Outputs section and create a new output column to store the excrypted password in. The encypted string will be larger than the original string so make sure it will fit.

New output column named EncryptedPassword

7) The Script
Hit the Edit Script button and remove the PreExecute and PostExecute methods because we don't need them. Copy the code below. I have created two new static methods (Encrypt and Decrypt) that will do the job. They are simplified versions of these examples at CodeProject. If you want to use these scripts commercially, make sure you read the documentation and test it thoroughly! I don't take any responsibility whatsoever.

// C# code
using System;
using System.Data;
using System.IO;                        // Added
using System.Security.Cryptography;     // Added
using Microsoft.SqlServer.Dts.Pipeline.Wrapper;
using Microsoft.SqlServer.Dts.Runtime.Wrapper;
using System.Windows.Forms;

[Microsoft.SqlServer.Dts.Pipeline.SSISScriptComponentEntryPointAttribute]
public class ScriptMain : UserComponent
{

    public override void Input0_ProcessInputRow(Input0Buffer Row)
    {
       // Fill the new column with an encrypted version of the password column.
        Row.EncryptedPassword = Encrypt(Row.Password.ToString(), this.Variables.EncryptionKey.ToString());
    }

    // Encrypt text with Rijndael encryption
    public static string Encrypt(string clearText, string Password)
    {
        // Convert password string into byte array
        byte[] clearBytes = System.Text.Encoding.Unicode.GetBytes(clearText);

        // Create Key and IV from the password with salt technique
        PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });

        // Create a symmetric algorithm with Rijndael
        Rijndael alg = Rijndael.Create();

        // Set Key and IV
        alg.Key = pdb.GetBytes(32);
        alg.IV = pdb.GetBytes(16);

        // Create a MemoryStream  
        MemoryStream ms = new MemoryStream();

        // Create a CryptoStream
        CryptoStream cs = new CryptoStream(ms, alg.CreateEncryptor(), CryptoStreamMode.Write);

        // Write the data and make it do the encryption 
        cs.Write(clearBytes, 0, clearBytes.Length);

        // Close CryptoStream
        cs.Close();

        // Get Encypted data from MemoryStream
        byte[] encryptedData = ms.ToArray();

        // return the Encypted data as a String
        return Convert.ToBase64String(encryptedData);
    }

    // Decrypt text with Rijndael encryption
    public static string Decrypt(string cipherText, string Password)
    {
        // Convert password string into byte array
        byte[] cipherBytes = Convert.FromBase64String(cipherText);

        // Create Key and IV from the password with salt technique
        PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });

        // Create a symmetric algorithm with Rijndael
        Rijndael alg = Rijndael.Create();

        // Set Key and IV
        alg.Key = pdb.GetBytes(32);
        alg.IV = pdb.GetBytes(16);

        // Create a MemoryStream  
        MemoryStream ms = new MemoryStream();

        // Create a CryptoStream 
        CryptoStream cs = new CryptoStream(ms, alg.CreateDecryptor(), CryptoStreamMode.Write);

        // Write the data and make it do the decryption 
        cs.Write(cipherBytes, 0, cipherBytes.Length);

        // Close CryptoStream
        cs.Close();

        // Get Decypted data from MemoryStream
        byte[] decryptedData = ms.ToArray();

        // return the Decypted data as a String
        return System.Text.Encoding.Unicode.GetString(decryptedData);
    }
}

Or VB.Net

' VB.Net code
Imports System
Imports System.Data
Imports System.IO                       ' Added
Imports System.Security.Cryptography    ' Added
Imports System.Math
Imports Microsoft.SqlServer.Dts.Pipeline.Wrapper
Imports Microsoft.SqlServer.Dts.Runtime.Wrapper

<Microsoft.SqlServer.Dts.Pipeline.SSISScriptComponentEntryPointAttribute> _
<CLSCompliant(False)> _
Public Class ScriptMain
    Inherits UserComponent

    Public Overrides Sub Input0_ProcessInputRow(ByVal Row As Input0Buffer)
        ' Fill the new column with an encrypted version of the password column.
        Row.EncryptedPassword = Encrypt(Row.Password.ToString(), Me.Variables.EncryptionKey.ToString())
    End Sub

    ' Encrypt text with Rijndael encryption
    Public Shared Function Encrypt(ByVal clearText As String, ByVal Password As String) As String
        ' Convert password string into byte array
        Dim clearBytes As Byte() = System.Text.Encoding.Unicode.GetBytes(clearText)

        ' Create Key and IV from the password with salt technique
        Dim pdb As New PasswordDeriveBytes(Password, New Byte() {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64, &H76, &H65, &H64, &H65, &H76})

        ' Create a symmetric algorithm with Rijndael
        Dim alg As Rijndael = Rijndael.Create()

        ' Set Key and IV
        alg.Key = pdb.GetBytes(32)
        alg.IV = pdb.GetBytes(16)

        ' Create a MemoryStream  
        Dim ms As MemoryStream = New MemoryStream()

        ' Create a CryptoStream
        Dim cs As CryptoStream = New CryptoStream(ms, alg.CreateEncryptor(), CryptoStreamMode.Write)

        ' Write the data and make it do the encryption 
        cs.Write(clearBytes, 0, clearBytes.Length)

        ' Close CryptoStream
        cs.Close()

        ' Get Encypted data from MemoryStream
        Dim encryptedData As Byte() = ms.ToArray()

        ' return the Encypted data as a String
        Encrypt = Convert.ToBase64String(encryptedData)
    End Function

    ' Decrypt text with Rijndael encryption
    Public Shared Function Decrypt(ByVal cipherText As String, ByVal Password As String) As String
        ' Convert password string into byte array
        Dim cipherBytes As Byte() = Convert.FromBase64String(cipherText)

        ' Create Key and IV from the password with salt technique
        Dim pdb As New PasswordDeriveBytes(Password, New Byte() {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64, &H76, &H65, &H64, &H65, &H76})

        ' Create a symmetric algorithm with Rijndael
        Dim alg As Rijndael = Rijndael.Create()

        ' Set Key and IV
        alg.Key = pdb.GetBytes(32)
        alg.IV = pdb.GetBytes(16)

        ' Create a MemoryStream  
        Dim ms As MemoryStream = New MemoryStream()

        ' Create a CryptoStream 
        Dim cs As CryptoStream = New CryptoStream(ms, alg.CreateDecryptor(), CryptoStreamMode.Write)

        ' Write the data and make it do the decryption 
        cs.Write(cipherBytes, 0, cipherBytes.Length)

        ' Close CryptoStream
        cs.Close()

        ' Get Decypted data from MemoryStream
        Dim decryptedData As Byte() = ms.ToArray()

        ' return the Decypted data as a String
        Decrypt = System.Text.Encoding.Unicode.GetString(decryptedData)
    End Function

End Class

8) The result
Now finish the Data Flow by adding a destination. I added a Data Viewer to see the result.

The result: encrypted data

9) Reverse
By reversing the Data Flow we can decrypt the data.

The result: decrypted data

// C# code
public override void Input0_ProcessInputRow(Input0Buffer Row)
{
    // Fill the new column with the decrypted version of the encrypted password column.
    Row.DecryptedPassword = Decrypt(Row.Password.ToString(), this.Variables.EncryptionKey.ToString());
}

Or VB.Net

' VB.Net code
Public Overrides Sub Input0_ProcessInputRow(ByVal Row As Input0Buffer)
    ' Fill the new column with the decrypted version of the encrypted password column.
    Row.DecryptedPassword = Decrypt(Row.Password.ToString(), Me.Variables.EncryptionKey.ToString())
End Sub

Note: This example uses Rijndael, but there are more methods available in .Net