Home » Customization » Encrypt Web Forms For Marketers Fields in Sitecore

Encrypt Web Forms For Marketers Fields in Sitecore

Sitecore Technology MVP 2016
Sitecore MVP 2015
Sitecore MVP 2014

Enter your email address to follow this blog and receive notifications of new posts by email.

Tweets

In an earlier post, I walked you through how I experimented with data encryption of field values in Sitecore, and alluded to how I had done a similar thing for the Web Forms For Marketers (WFFM) module on a past project at work.

Months have gone by, and guilt has begun to gnaw away at my entire being — no, not really, I’m exaggerating a bit — but I definitely have been feeling bad for not sharing a solution.

In order to shake feeling bad, I decided to put my nose to the grindstone over the past few days to come up with a different solution than the one I had built at work, and this post shows the fruits of that labor.

I decided to reuse the interface I had created in my older post on data encryption. I am re-posting it here for reference:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace Sitecore.Sandbox.Security.Encryption.Base
{
    public interface IEncryptor
    {
        string Encrypt(string input);
 
        string Decrypt(string input);
    }
}

I then asked myself “What encryption algorithm should I use?” I scavenged through the System.Security.Cryptography namespace in mscorlib.dll using .NET Reflector, and discovered some classes, when used together, achieve data encryption using the RC2 algorithm — an algorithm I know nothing about:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

using Sitecore.Diagnostics;

using Sitecore.Sandbox.Security.Encryption.Base;

namespace Sitecore.Sandbox.Security.Encryption
{
    public class RC2Encryptor : IEncryptor
    {
        public string Key { get; set; }

        private RC2Encryptor(string key)
        {
            SetKey(key);
        }

        private void SetKey(string key)
        {
            Assert.ArgumentNotNullOrEmpty(key, "key");
            Key = key;
        }

        public string Encrypt(string input)
        {
            return Encrypt(input, Key);
        }

        public static string Encrypt(string input, string key)
        {
            byte[] inputArray = UTF8Encoding.UTF8.GetBytes(input);
            RC2CryptoServiceProvider rc2 = new RC2CryptoServiceProvider();
            rc2.Key = UTF8Encoding.UTF8.GetBytes(key);
            rc2.Mode = CipherMode.ECB;
            rc2.Padding = PaddingMode.PKCS7;
            ICryptoTransform cTransform = rc2.CreateEncryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
            rc2.Clear();
            return System.Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }

        public string Decrypt(string input)
        {
            return Decrypt(input, Key);
        }

        public static string Decrypt(string input, string key)
        {
            byte[] inputArray = System.Convert.FromBase64String(input);
            RC2CryptoServiceProvider rc2 = new RC2CryptoServiceProvider();
            rc2.Key = UTF8Encoding.UTF8.GetBytes(key);
            rc2.Mode = CipherMode.ECB;
            rc2.Padding = PaddingMode.PKCS7;
            ICryptoTransform cTransform = rc2.CreateDecryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
            rc2.Clear();
            return UTF8Encoding.UTF8.GetString(resultArray);
        }

        public static IEncryptor CreateNewRC2Encryptor(string key)
        {
            return new RC2Encryptor(key);
        }
    }
}

As I had mentioned in my previous post on data encryption, I am not a cryptography expert, nor a security expert.

I am not aware of how strong the RC2 encryption algorithm is, or what it would take to crack it. I strongly advise against using this algorithm in any production system without first consulting with a security expert. I am using it in this post only as an example.

If you happen to be a security expert, or are able to compare encryption algorithms defined in the System.Security.Cryptography namespace in mscorlib.dll, please share in a comment.

In a previous post on manipulating field values for WFFM forms, I had to define a new class that implements Sitecore.Forms.Data.IField in Sitecore.Forms.Core.dll in order to change field values — it appears the property mutator for the “out of the box” class is ignored — and decided to reuse it here:

using System;

using Sitecore.Forms.Data;

namespace Sitecore.Sandbox.Utilities.Manipulators.DTO
{
    public class WFFMField : IField
    {
        public string Data { get; set; }

        public Guid FieldId { get; set; }

        public string FieldName { get; set; }

        public IForm Form { get; set; }

        public Guid Id { get; internal set; }

        public string Value { get; set; }
    }
}

Next, I created a WFFM Data Provider that encrypts and decrypts field names and values:

using System;
using System.Collections.Generic;

using Sitecore.Configuration;
using Sitecore.Diagnostics;
using Sitecore.Forms.Data;
using Sitecore.Forms.Data.DataProviders;
using Sitecore.Reflection;

using Sitecore.Sandbox.Security.DTO;
using Sitecore.Sandbox.Security.Encryption.Base;
using Sitecore.Sandbox.Security.Encryption;
using Sitecore.Sandbox.Utilities.Manipulators.DTO;

namespace Sitecore.Sandbox.WFFM.Forms.Data.DataProviders
{
    public class WFFMEncryptionDataProvider : WFMDataProviderBase
    {
        private WFMDataProviderBase InnerProvider { get; set; }
        private IEncryptor Encryptor { get; set; }

        public WFFMEncryptionDataProvider(string innerProvider)
            : this(CreateInnerProvider(innerProvider), CreateDefaultEncryptor())
        {
        }

        public WFFMEncryptionDataProvider(string connectionString, string innerProvider)
            : this(CreateInnerProvider(innerProvider, connectionString), CreateDefaultEncryptor())
        {
        }

        public WFFMEncryptionDataProvider(WFMDataProviderBase innerProvider)
            : this(innerProvider, CreateDefaultEncryptor())
        {
        }

        public WFFMEncryptionDataProvider(WFMDataProviderBase innerProvider, IEncryptor encryptor)
        {
            SetInnerProvider(innerProvider);
            SetEncryptor(encryptor);
        }

        private static WFMDataProviderBase CreateInnerProvider(string innerProvider, string connectionString = null)
        {
            Assert.ArgumentNotNullOrEmpty(innerProvider, "innerProvider");
            if (!string.IsNullOrWhiteSpace(connectionString))
            {
                return ReflectionUtil.CreateObject(innerProvider, new[] { connectionString }) as WFMDataProviderBase;
            }

            return ReflectionUtil.CreateObject(innerProvider, new object[0]) as WFMDataProviderBase;
        }
        
        private void SetInnerProvider(WFMDataProviderBase innerProvider)
        {
            Assert.ArgumentNotNull(innerProvider, "innerProvider");
            InnerProvider = innerProvider;
        }

        private static IEncryptor CreateDefaultEncryptor()
        {
            return DataNullTerminatorEncryptor.CreateNewDataNullTerminatorEncryptor(GetEncryptorSettings());
        }

        private static DataNullTerminatorEncryptorSettings GetEncryptorSettings()
        {
            return new DataNullTerminatorEncryptorSettings
            {
                EncryptionDataNullTerminator = Settings.GetSetting("WFFM.Encryption.DataNullTerminator"),
                InnerEncryptor = RC2Encryptor.CreateNewRC2Encryptor(Settings.GetSetting("WFFM.Encryption.Key"))
            };
        }

        private void SetEncryptor(IEncryptor encryptor)
        {
            Assert.ArgumentNotNull(encryptor, "encryptor");
            Encryptor = encryptor;
        }

        public override void ChangeStorage(Guid formItemId, string newStorage)
        {
            InnerProvider.ChangeStorage(formItemId, newStorage);
        }

        public override void ChangeStorageForForms(IEnumerable<Guid> ids, string storageName)
        {
            InnerProvider.ChangeStorageForForms(ids, storageName);
        }

        public override void DeleteForms(IEnumerable<Guid> formSubmitIds)
        {
            InnerProvider.DeleteForms(formSubmitIds);
        }

        public override void DeleteForms(Guid formItemId, string storageName)
        {
            InnerProvider.DeleteForms(formItemId, storageName);
        }

        public override IEnumerable<IPool> GetAbundantPools(Guid fieldId, int top, out int total)
        {
            return InnerProvider.GetAbundantPools(fieldId, top, out total);
        }

        public override IEnumerable<IForm> GetForms(QueryParams queryParams, out int total)
        {
            IEnumerable<IForm> forms = InnerProvider.GetForms(queryParams, out total);
            DecryptForms(forms);
            return forms;
        }

        public override IEnumerable<IForm> GetFormsByIds(IEnumerable<Guid> ids)
        {
            IEnumerable<IForm> forms = InnerProvider.GetFormsByIds(ids);
            DecryptForms(forms);
            return forms;
        }

        public override int GetFormsCount(Guid formItemId, string storageName, string filter)
        {
            return InnerProvider.GetFormsCount(formItemId, storageName, filter);
        }

        public override IEnumerable<IPool> GetPools(Guid fieldId)
        {
            return InnerProvider.GetPools(fieldId);
        }

        public override void InsertForm(IForm form)
        {
            EncryptForm(form);
            InnerProvider.InsertForm(form);
        }

        public override void ResetPool(Guid fieldId)
        {
            InnerProvider.ResetPool(fieldId);
        }

        public override IForm SelectSingleForm(Guid fieldId, string likeValue)
        {
            IForm form = InnerProvider.SelectSingleForm(fieldId, likeValue);
            DecryptForm(form);
            return form;
        }

        public override bool UpdateForm(IForm form)
        {
            EncryptForm(form);
            return InnerProvider.UpdateForm(form);
        }

        private void EncryptForms(IEnumerable<IForm> forms)
        {
            Assert.ArgumentNotNull(forms, "forms");
            foreach (IForm form in forms)
            {
                EncryptForm(form);
            }
        }

        private void EncryptForm(IForm form)
        {
            Assert.ArgumentNotNull(form, "form");
            Assert.ArgumentNotNull(form.Field, "form.Field");
            form.Field = EncryptFields(form.Field);
        }

        private IEnumerable<IField> EncryptFields(IEnumerable<IField> fields)
        {
            Assert.ArgumentNotNull(fields, "fields");
            IList<IField> encryptedFields = new List<IField>();
            foreach (IField field in fields)
            {
                encryptedFields.Add(EncryptField(field));
            }

            return encryptedFields;
        }

        private IField EncryptField(IField field)
        {
            Assert.ArgumentNotNull(field, "field");
            return CreateNewWFFMField(field, Encrypt(field.FieldName), Encrypt(field.Value));
        }

        private void DecryptForms(IEnumerable<IForm> forms)
        {
            Assert.ArgumentNotNull(forms, "forms");
            foreach (IForm form in forms)
            {
                DecryptForm(form);
            }
        }

        private void DecryptForm(IForm form)
        {
            Assert.ArgumentNotNull(form, "form");
            Assert.ArgumentNotNull(form.Field, "form.Field");
            form.Field = DecryptFields(form.Field);
        }

        private IEnumerable<IField> DecryptFields(IEnumerable<IField> fields)
        {
            Assert.ArgumentNotNull(fields, "fields");
            IList<IField> decryptedFields = new List<IField>();
            foreach (IField field in fields)
            {
                decryptedFields.Add(DecryptField(field));
            }

            return decryptedFields;
        }

        private IField DecryptField(IField field)
        {
            Assert.ArgumentNotNull(field, "field");
            return CreateNewWFFMField(field, Decrypt(field.FieldName), Decrypt(field.Value));
        }

        private string Encrypt(string input)
        {
            return Encryptor.Encrypt(input);
        }

        private string Decrypt(string input)
        {
            return Encryptor.Decrypt(input);
        }

        private static IField CreateNewWFFMField(IField field, string fieldName, string value)
        {
            if (field != null)
            {
                return new WFFMField
                {
                    Data = field.Data,
                    FieldId = field.FieldId,
                    FieldName = fieldName,
                    Form = field.Form,
                    Id = field.Id,
                    Value = value
                };
            }

            return null;
        }
    }
}

The above class employs the decorator pattern. An inner WFFM Data Provider — which is supplied via a parameter configuration node in \App_Config\Include\forms.config, and is created via magic within the Sitecore.Reflection.ReflectionUtil class — is wrapped.

Methods that save and retrieve form data in the above Data Provider decorate the same methods defined on the inner WFFM Data Provider.

Methods that save form data pass form(s) — and eventually their fields — through a chain of Encrypt methods. The Encrypt method that takes in an IField instance as an argument encrypts the instance’s field name and value, and returns a new instance of the WFFMField class using the encrypted data and the other properties on the IField instance untouched.

Similarly, a chain of Decrypt methods are called for form(s) being retrieved from the inner Data Provider — field names and values are decrypted and saved into a new instance of the WFFMField class, and the manipulated form(s) are returned.

I want to point out that the IEncryptor instance is actually an instance of DataNullTerminatorEncryptor — see my earlier post on data encryption to see how this is implemented — which decorates our RC2Encryptor. This decorating encryptor stamps encrypted strings with a special string so we don’t accidentally encrypt a value twice, and it also won’t try to decrypt a string value that isn’t encrypted.

I added a new include configuration file to hold encryption related settings — the IEncryptor’s key, and the string that will be put at the end of all encrypted data via the DataNullTerminatorEncryptor instance:

<?xml version="1.0" encoding="utf-8"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <settings>
      <!-- TODO: change the terminator so it does not scream "PLEASE TRY TO CRACK ME!" -->
      <setting name="WFFM.Encryption.DataNullTerminator" value="#I_AM_ENCRYPTED#" />

      <!-- I found this key somewhere on the internet, so it must be secure -->
      <setting name="WFFM.Encryption.Key" value="88bca90e90875a" />
    </settings>
  </sitecore>
</configuration>

I then hooked in the encryption WFFM Data Provider in \App_Config\Include\forms.config, and set the type for the inner provider:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:x="http://www.sitecore.net/xmlconfig/">
  <sitecore>
  
	<!-- There is stuff up here -->
  
	<!-- MS SQL -->
	<formsDataProvider type="Sitecore.Sandbox.WFFM.Forms.Data.DataProviders.WFFMEncryptionDataProvider, Sitecore.Sandbox">
		<!-- No, this is not my real connection string -->
		<param desc="connection string">user id=(user);password=(password);Data Source=(database)</param>
		<param desc="inner provider">Sitecore.Forms.Data.DataProviders.WFMDataProvider, Sitecore.Forms.Core</param>
	</formsDataProvider>

	<!-- There is stuff down here -->
	
	</sitecore>
</configuration>

Let’s see this in action.

I created a new WFFM form with some fields for testing:

the-form-in-sitecore

I then mapped the above form to a new page in Sitecore, and published both the form and page.

I navigated to the form page, and filled it out:

the-form-page

After clicking submit, I was given a ‘thank you’ page’:

the-form-page-confirmation

Let’s see what our field data looks like in the WFFM database:

the-form-submission-encrypted-db

As you can see, the data is encrypted.

Now, let’s see if the data is also encrypted in the Forms Report for our test form:

forms-report-encryption

As you can see, the end-user would be unaware that any data manipulation is happening under the hood.

If you have any thoughts on this, please leave a comment.

Advertisements

2 Comments

  1. chad3c says:

    Awesome post. Very helpful for what I needed.

    I made a few modifications. If you are going through the trouble of encrypting, don’t use RC2, but use TripleDES or AES. I implemented AES 256. I also changed the DataNullTerminatorEncryptor to leave empty strings alone, and not try to concatenate the terminator. Lastly, I wanted to encrypt the value and data fields, not the field name, as those were what the customer typed or selected.

    For anyone implementing this, some of the needed code is in the other experiments post.

    Thanks for the writeup!

Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: