# Cloak.Ecto
[](https://coveralls.io/github/danielberkompas/cloak_ecto?branch=master)
[](https://travis-ci.org/danielberkompas/cloak_ecto)
Easily encrypt fields in your [Ecto](https://github.com/elixir-ecto/ecto)
schemas. Relies on [Cloak](https://github.com/danielberkompas/cloak) for
encryption.
- [Hex Documentation](https://hexdocs.pm/cloak_ecto)
## Usage
`Cloak.Ecto` helps you create `Ecto.Type` modules which automatically encrypt
and decrypt your data. You simply set the type of your fields, and
`Cloak.Ecto` handles the rest.
```elixir
defmodule MyApp.EctoSchema do
use Ecto.Schema
schema "table_name" do
field :encrypted_field, MyApp.Encrypted.Binary
# ...
end
end
```
When Ecto writes the fields to the database, Cloak encrypts the values into a
binary blob, using a configured encryption algorithm chosen by you.
```elixir
iex> Repo.insert!(%MyApp.EctoSchema{encrypted_field: "plaintext"})
08:46:08.862 [debug] QUERY OK db=3.4ms
INSERT INTO "table_name" ("encrypted_field")
VALUES ($1) RETURNING "id", "encrypted_field" [
<<1,10, 65, 69, 83, 46, 67, 84, 82, 46, 86, 49,
69, 92, 173, 219, 203, 238, 26, 58, 236, 5,
104, 23, 12, 10, 182, 31, 221, 89, 22, 58,
34, 79, 109, 30, 70, 254, 56, 93, 102, 84>>
]
```
Likewise, when Ecto reads the encrypted blob out of the database, Cloak will
automatically decrypt the value into the intended data type at runtime.
```elixir
iex> Repo.get(MyApp.EctoSchema, 1)
%MyApp.EctoSchema{encrypted_field: "plaintext"}
```
For complete usage instructions, see the [Hex documentation](https://hexdocs.pm/cloak_ecto).
## Notable Features
- Transparent, easy to use encryption for database fields
- Fully compatible with umbrella projects
- Bring your own encryption algorithm, if you want
- Mix task for key rotation: `mix cloak.migrate`
## Security Notes
- **Supported Algorithms**: Cloak's built-in encryption modules rely on Erlang's
`:crypto` module. Cloak supports the following algorithms out of the box:
- AES.GCM
- AES.CTR
- **Encrypted Data Not Searchable**: Cloak uses random IVs for each ciphertext. This
means that the same value will not encrypt to the same value twice. As a result,
encrypted columns are not queryable. However, Cloak does provide easy ways to
create hashed, searchable columns.
- **Runtime Data is not Encrypted**: Cloak encrypts data _at rest_ in the database.
The data in your Ecto structs at runtime is not encrypted.
- **No Support for User-specific Encryption Keys**: Cloak's `Ecto.Type` modules do not
support user-specific encryption keys, due to limitations on the `Ecto.Type`
behaviour. However, you can still use Cloak's ciphers to implement these in your
application logic.
## Use Without Ecto
If you want to use `Cloak` without Ecto, see
[`cloak`](https://hex.pm/packages/cloak) instead.
