auth – Flamego

auth

The auth middleware provides request authentication for Flame instances, including basic and bearer authentications.

You can read source code of this middleware on GitHub and API documentation on pkg.go.dev.

Installation

go get github.com/flamego/auth

Usage examples

Basic authentication

The auth.Basic takes a static combination of username and password to protect routes behind it. Upon successful authentication, the auth.User is injected into the request context, which simply contains the username:

package main

import (
	"github.com/flamego/auth"
	"github.com/flamego/flamego"
)

func main() {
	f := flamego.Classic()
	f.Use(auth.Basic("username", "secretpassword"))
	f.Get("/", func(user auth.User) string {
		return "Welcome, " + string(user)
	})
	f.Run()
}

The auth.BasicFunc can be used to support dynamic combinations of username and password:

package main

import (
	"github.com/flamego/auth"
	"github.com/flamego/flamego"
)

func main() {
	credentials := map[string]string{
		"alice": "pa$$word",
		"bob":   "secretpassword",
	}

	f := flamego.Classic()
	f.Use(auth.BasicFunc(func(username, password string) bool {
		return auth.SecureCompare(credentials[username], password)
	}))
	f.Get("/", func(user auth.User) string {
		return "Welcome, " + string(user)
	})
	f.Run()
}

The auth.SecureCompare is a function that does constant time compare of two strings to prevent timing attacks.

Bearer authentication

The auth.Bearer takes a static token to protect routes behind it. Upon successful authentication, the auth.Token is injected into the request context, which simply contains the token:

package main

import (
	"github.com/flamego/auth"
	"github.com/flamego/flamego"
)

func main() {
	f := flamego.Classic()
	f.Use(auth.Bearer("secrettoken"))
	f.Get("/", func(token auth.Token) string {
		return "Authenticated through " + string(token)
	})
	f.Run()
}

The auth.BearerFunc can be used to support dynamic tokens:

package main

import (
	"github.com/flamego/auth"
	"github.com/flamego/flamego"
)

func main() {
	tokens := map[string]struct{}{
		"token":       {},
		"secrettoken": {},
	}

	f := flamego.Classic()
	f.Use(auth.BearerFunc(func(token string) bool {
		_, ok := tokens[token]
		return ok
	}))
	f.Get("/", func(token auth.Token) string {
		return "Authenticated through " + string(token)
	})
	f.Run()
}