X.EntityFrameworkCore.FieldEncryption 1.8.2.1

Disclaimer

<h4 align="center">:warning: This project is not affiliated with Microsoft. ⚠️</h4><br>

This library has been developed initialy for a personal project of mine which suits my use case. It provides a simple way to encrypt column data.

I do not take responsability if you use/deploy this in a production environment and loose your encryption key or corrupt your data.

How to install

Install the package from NuGet or from the Package Manager Console :

PM> Install-Package X.EntityFrameworkCore.FieldEncryption

Supported types

How to use

X.EntityFrameworkCore.FieldEncryption supports 2 differents initialization methods:

• Attribute
• Fluent configuration

Depending on the initialization method you will use, you will need to decorate your string or byte[] properties of your entities with the [Encrypted] attribute or use the fluent IsEncrypted() method in your model configuration process. To use an encryption provider on your EF Core model, and enable the encryption on the ModelBuilder.

Example with AesFieldEncryptionProvider and attribute

public class UserEntity
{
	public int Id { get; set; }
	
	[Encrypted]
	public string Username { get; set; }
	
	[Encrypted]
	public string Password { get; set; }
	
	public int Age { get; set; }
}

public class DatabaseContext : DbContext
{
	// Get key and IV from a Base64String or any other ways.
	// You can generate a key and IV using "AesFieldEncryptionProvider.GenerateKey()"
	private readonly byte[] _encryptionKey = ...; 
	private readonly byte[] _encryptionIV = ...;
	private readonly IFieldEncryptionProvider _provider;

	public DbSet<UserEntity> Users { get; set; }
	
	public DatabaseContext(DbContextOptions options)
		: base(options)
	{
		_provider = new AesFieldEncryptionProvider(this._encryptionKey, this._encryptionIV);
	}
	
	protected override void OnModelCreating(ModelBuilder modelBuilder)
	{
		modelBuilder.UseEncryption(_provider);
	}
}

The code bellow creates a new AesFieldEncryptionProvider and gives it to the current model. It will encrypt every string fields of your model that has the [Encrypted] attribute when saving changes to database. As for the decrypt process, it will be done when reading the DbSet<T> of your DbContext.

Example with AesFieldEncryptionProvider and fluent configuration

public class UserEntity
{
	public int Id { get; set; }
	public string Username { get; set; }
	public string Password { get; set; }
	public int Age { get; set; }
}

public class DatabaseContext : DbContext
{
	// Get key and IV from a Base64String or any other ways.
	// You can generate a key and IV using "AesFieldEncryptionProvider.GenerateKey()"
	private readonly byte[] _encryptionKey = ...; 
	private readonly byte[] _encryptionIV = ...;
	private readonly IFieldEncryptionProvider _provider;

	public DbSet<UserEntity> Users { get; set; }
	
	public DatabaseContext(DbContextOptions options)
		: base(options)
	{
		_provider = new AesFieldEncryptionProvider(this._encryptionKey, this._encryptionIV);
	}
	
	protected override void OnModelCreating(ModelBuilder modelBuilder)
	{
		// Entities builder *MUST* be called before UseEncryption().
		var userEntityBuilder = modelBuilder.Entity<UserEntity>();
		
		userEntityBuilder.Property(x => x.Username).IsRequired().IsEncrypted();
		userEntityBuilder.Property(x => x.Password).IsRequired().IsEncrypted();

		modelBuilder.UseEncryption(_provider);
	}
}

Create an encryption provider

X.EntityFrameworkCore.FieldEncryption gives the possibility to create your own encryption providers. To do so, create a new class and make it inherit from IFieldEncryptionProvider. You will need to implement the Encrypt(string) and Decrypt(string) methods.

public class MyCustomEncryptionProvider : IFieldEncryptionProvider
{
	public byte[] Encrypt(byte[] input)
	{
		// Encrypt the given input and return the encrypted data as a byte[].
	}
	
	public byte[] Decrypt(byte[] input)
	{
		// Decrypt the given input and return the decrypted data as a byte[].
	}
}

To use it, simply create a new MyCustomEncryptionProvider in your DbContext and pass it to the UseEncryption method:

public class DatabaseContext : DbContext
{
	private readonly IFieldEncryptionProvider _provider;

	public DatabaseContext(DbContextOptions options)
		: base(options)
	{
		_provider = new MyCustomEncryptionProvider();
	}

	protected override void OnModelCreating(ModelBuilder modelBuilder)
	{
		modelBuilder.UseEncryption(_provider);
	}
}