如何在Kotlin的Ktor中提取访问权限验证

import io.ktor.application.*
import io.ktor.auth.*
import io.ktor.features.ContentNegotiation
import io.ktor.http.HttpStatusCode
import io.ktor.jackson.jackson
import io.ktor.request.receive
import io.ktor.response.respond
import io.ktor.routing.*
import io.ktor.server.engine.embeddedServer
import io.ktor.server.netty.Netty

data class User(val username: String, val password: String)

val users = listOf(
    User("admin", "admin123"),
    User("user", "user123")
)

fun Application.module() {
    install(ContentNegotiation) {
        jackson { }
    }

    install(Authentication) {
        basic {
            realm = "Ktor Server"
            validate { credentials ->
                val user = users.find { it.username == credentials.name }
                if (user != null && user.password == credentials.password) {
                    UserIdPrincipal(credentials.name)
                } else {
                    null
                }
            }
        }
    }

    routing {
        authenticate {
            get("/protected") {
                call.respond(HttpStatusCode.OK, "Access granted")
            }
        }

        post("/login") {
            val credentials = call.receive<User>()
            val principal = call.authentication.principal<UserIdPrincipal>()
            if (principal != null) {
                call.respond(HttpStatusCode.OK, "Login successful")
            } else {
                call.respond(HttpStatusCode.Unauthorized, "Invalid credentials")
            }
        }
    }
}

fun main() {
    embeddedServer(Netty, port = 8080, module = Application::module).start(wait = true)
}