# Felix
Allows user to create a new account or log in by providing a passkey.
WebAuthN/Fido2 integration.
[](https://hex.pm/packages/felix)
[](https://hexdocs.pm/felix/)
## JS only
This library is bindings for the [SimpleWebAuthn server package](https://github.com/MasterKale/SimpleWebAuthn/).
Therefore it only works on JS server environments.
*I have a prototype for pure Gleam implementation but it is incomplete, get in touch if you need the use of an erlang based implementation.*
## Usage
```sh
npm i --save @simplewebauthn/server
gleam add felix@1
```
### Verify registration
```gleam
import felix/server
pub fn verify_registration(response: String) {
// generated for each registration and sent to the client earlier
let expected_challenge =
bit_array.base64_url_encode(<<"secret challenge">>, False)
use #(verified, info) <- promise.map_try(server.verify_registration(
response: response,
expected_challenge: expected_challenge,
expected_origin: "http://localhost:8080",
// rpid matches origin without scheme and port
expected_rpid: "localhost",
require_user_presence: False,
require_user_verification: False,
))
case verified {
True ->
// save the info.public_key in your database
Ok(Nil)
False -> Error("invalid")
}
}
```
**NOTE:** client side registration can be handled using the [plinth](https://github.com/crowdhailer/plinth) library bindings to the Web credentials API.
```gleam
import plinth/browser/credentials
import plinth/browser/credentials/public_key
pub fn main(){
let assert Ok(container) = credentials.from_navigator()
let options =
public_key.creation(
<<"secret challenge">>,
public_key.ES256,
"New service",
<<"my user id">>,
"bob@example.com",
"Bob",
)
use response <- promise.try_await(public_key.create(container, options))
let response = json.to_string(public_key.to_json(response))
// send to server to validate_registration
}
```
### Verify authentication
```gleam
import felix/server
pub fn verify_authentication_test(response) {
// generated for each authentication
let expected_challenge =
bit_array.base64_url_encode(<<"another secret">>, False)
let public_key = todo as "pull from DB"
use #(verified, info) <- promise.map_try(server.verify_authentication(
response: response,
expected_challenge: expected_challenge,
expected_origin: "http://localhost:8080",
expected_rpid: "localhost",
public_key: public_key,
require_user_verification: False,
))
verified
|> should.be_true
info.user_verified
|> should.be_true
info.credential_device_type
|> should.equal(server.MultiDevice)
info.credential_backed_up
|> should.be_true
info.origin
|> should.equal("http://localhost:8080")
info.rp_id
|> should.equal("localhost")
Ok(Nil)
}
```
**NOTE:** client side registration can be handled using the [plinth](https://github.com/crowdhailer/plinth) library bindings to the Web credentials API.
```gleam
import plinth/browser/credentials
import plinth/browser/credentials/public_key
pub fn main(){
let assert Ok(container) = credentials.from_navigator()
let options = public_key.request(<<"another secret">>)
use response <- promise.try_await(public_key.get(container, options))
let response = json.to_string(public_key.to_json(response))
// send to server to validate_authentication
}
```
---
Further documentation can be found at <https://hexdocs.pm/felix>.
## Development
```sh
gleam run # Run the project
gleam test # Run the tests
```
## Credit
Created for [EYG](https://eyg.run/), a new integration focused programming language.
