Ktor Authenticator

this is a ktor plugin for more authentication schema.

1. firebase authentication
2. header authentication (like 'API_KEY', 'X_API_KEY' and more.....)

Installation

repositories {
    mavenCentral()
    maven { url 'https://jitpack.io' }
}

dependencies {
    implementation("com.github.koron0902:KtorAuthenticator:0.1.6")
}

Usage

Firebase Authenticate

Pre-Requirements

• firebase_admin.json

Supported authentication keyword

JWT

when use JWT, request header format is Authorization: JWT xxxxxxxxxxxx

Bearer

when use Bearer, request header format is Authorization: Bearer xxxxxxxxxxxx

Handle errors

FirebaseAuthProvider throws these exceptions when authentication failed.

TokenNotProvidedException

throws when request header not contains Authorization

ClaimNotFoundException

throws when malformed Authorization header.
example

• Authorization: JWTxxxxxxxxxxxxxxxxxxxxxxxx
• Authorization: xxxxxxxxxxxxxxxxxx

correct format is Authorization: JWT xxxxxxxxxxxxxxxxxx

FirebaseAuthException

firebase library's exception.
throws on token which provided from client is not correct, expired, or user is disabled(when checkRevoked is true)

IllegalArgumentException

throws when FirebaseApp is not valid

sample

setup firebase authorization with Authentication plugin

install(Authentication){
    firebase("firebase") { // name is optional. if not set 'FIREBASE_AUTH' is used
        firebaseApp = <your firebase instance>
        authorizationType = FirebaseAuthProvider.AuthorizationType.Jwt
        checkRevoked = false
        whenReject = { call, throwable ->
            when(throwable){
                is FirebaseAuthProvider.TokenNotProvidedException ->{
                    call.respondText("token is not provided", status = HttpStatusCode.Unauthorized)
                }
                is FirebaseAuthException ->{
                    call.respondText("firebase auth failed", status = HttpStatusCode.Unauthorized)
                }
                is IllegalArgumentException ->{
                    call.respondText("some error occured", status = HttpStatusCode.Unauthorized)
                }
                is FirebaseAuthProvider.ClaimNotProvidedException ->{
                    call.respondText("missing token", status = HttpStatusCode.Unauthorized)
                }
            }
        }
    }
}

now, you can use firebase authentication.

routing {
    authenticate("firebase") {
        get("/firebase"){
            call.respondText("firebase jwt")
        }
    }

    get("/") {
        call.respondText("Hello, World!")
    }
}

Header Authenticate

when use this, you can use more authentication schema.

Validation

validate func called with ApplicationCall and <HeaderValue>, so you can check this.
if value is correct you should return true, otherwise return false

Handling errors

HeaderAuthProvider throws these exceptions when authentication failed.

HeaderNotProvidedException

throws when specified header is not passed.

ValidateFailedException

throws when validate returns false

install(Authentication){
    header(name = "meow"){
        headerName = "meow"
        validate = { call, headerValue ->
            headerValue == "meow!!!!"
        }
        whenReject = { call, throwable ->
            when(throwable){
                is HeaderAuthProvider.HeaderNotProvidedException ->{
                    call.respondText("header is not provided(meow)", status = HttpStatusCode.Unauthorized)
                }
                is HeaderAuthProvider.ValidateFailedException ->{
                    call.respondText("header value is not correct(meow)", status = HttpStatusCode.Unauthorized)

                }
            }
        }
    }
}

routing {
    authenticate("meow") {
        get("/meow"){
            call.respondText("meow!")
        }
    }
    get("/") {
        call.respondText("Hello, World!")
    }
}