KeyAuth

The KeyAuth middleware implements API key authentication.

Signatures

func New(config ...Config) fiber.Handler
func TokenFromContext(c fiber.Ctx) string

Examples

Basic example

This example registers KeyAuth with an API key stored in a cookie.

package main

import (
    "crypto/sha256"
    "crypto/subtle"
    "github.com/gofiber/fiber/v3"
    "github.com/gofiber/fiber/v3/middleware/keyauth"
)

var (
    apiKey = "correct horse battery staple"
)

func validateAPIKey(c fiber.Ctx, key string) (bool, error) {
    hashedAPIKey := sha256.Sum256([]byte(apiKey))
    hashedKey := sha256.Sum256([]byte(key))

    if subtle.ConstantTimeCompare(hashedAPIKey[:], hashedKey[:]) == 1 {
        return true, nil
    }
    return false, keyauth.ErrMissingOrMalformedAPIKey
}

func main() {
    app := fiber.New()

    // Register middleware before the routes that need it
    app.Use(keyauth.New(keyauth.Config{
        Extractor:  keyauth.FromCookie("access_token"),
        Validator:  validateAPIKey,
    }))

    app.Get("/", func(c fiber.Ctx) error {
        return c.SendString("Successfully authenticated!")
    })

    app.Listen(":3000")
}

Test:

# No API key specified -> 401 Missing or invalid API Key
curl http://localhost:3000
#> Missing or invalid API Key

# Correct API key -> 200 OK
curl --cookie "access_token=correct horse battery staple" http://localhost:3000
#> Successfully authenticated!

# Incorrect API key -> 401 Missing or invalid API Key
curl --cookie "access_token=Clearly A Wrong Key" http://localhost:3000
#> Missing or invalid API Key

For a more detailed example, see the fiber-envoy-extauthz recipe in the gofiber/recipes repository.

Authenticate only certain endpoints

Use the Next function to run KeyAuth only on selected routes.

package main

import (
    "crypto/sha256"
    "crypto/subtle"
    "github.com/gofiber/fiber/v3"
    "github.com/gofiber/fiber/v3/middleware/keyauth"
    "regexp"
    "strings"
)

var (
    apiKey        = "correct horse battery staple"
    protectedURLs = []*regexp.Regexp{
        regexp.MustCompile("^/authenticated$"),
        regexp.MustCompile("^/auth2$"),
    }
)

func validateAPIKey(c fiber.Ctx, key string) (bool, error) {
    hashedAPIKey := sha256.Sum256([]byte(apiKey))
    hashedKey := sha256.Sum256([]byte(key))

    if subtle.ConstantTimeCompare(hashedAPIKey[:], hashedKey[:]) == 1 {
        return true, nil
    }
    return false, keyauth.ErrMissingOrMalformedAPIKey
}

func authFilter(c fiber.Ctx) bool {
    originalURL := strings.ToLower(c.OriginalURL())

    for _, pattern := range protectedURLs {
        if pattern.MatchString(originalURL) {
            // Run middleware for protected routes
            return false
        }
    }
    // Skip middleware for non-protected routes
    return true
}

func main() {
    app := fiber.New()

    app.Use(keyauth.New(keyauth.Config{
        Next:      authFilter,
        Extractor: keyauth.FromCookie("access_token"),
        Validator: validateAPIKey,
    }))

    app.Get("/", func(c fiber.Ctx) error {
        return c.SendString("Welcome")
    })
    app.Get("/authenticated", func(c fiber.Ctx) error {
        return c.SendString("Successfully authenticated!")
    })
    app.Get("/auth2", func(c fiber.Ctx) error {
        return c.SendString("Successfully authenticated 2!")
    })

    app.Listen(":3000")
}

Test:

# / doesn't require authentication
curl http://localhost:3000
#> Welcome

# /authenticated requires authentication
curl --cookie "access_token=correct horse battery staple" http://localhost:3000/authenticated
#> Successfully authenticated!

# /auth2 requires authentication too
curl --cookie "access_token=correct horse battery staple" http://localhost:3000/auth2
#> Successfully authenticated 2!

Apply middleware in the handler

You can apply the middleware to specific routes or groups instead of globally. This example uses the default extractor (FromAuthHeader).

package main

import (
    "crypto/sha256"
    "crypto/subtle"
    "github.com/gofiber/fiber/v3"
    "github.com/gofiber/fiber/v3/middleware/keyauth"
)

const (
  apiKey = "my-super-secret-key"
)

func main() {
    app := fiber.New()

    authMiddleware := keyauth.New(keyauth.Config{
        Validator:  func(c fiber.Ctx, key string) (bool, error) {
            hashedAPIKey := sha256.Sum256([]byte(apiKey))
            hashedKey := sha256.Sum256([]byte(key))

            if subtle.ConstantTimeCompare(hashedAPIKey[:], hashedKey[:]) == 1 {
                return true, nil
            }
            return false, keyauth.ErrMissingOrMalformedAPIKey
        },
    })

    app.Get("/", func(c fiber.Ctx) error {
        return c.SendString("Welcome")
    })

    app.Get("/allowed",  authMiddleware, func(c fiber.Ctx) error {
        return c.SendString("Successfully authenticated!")
    })

    app.Listen(":3000")
}

Test:

# / doesn't require authentication
curl http://localhost:3000
#> Welcome

# /allowed requires authentication
curl --header "Authorization: Bearer my-super-secret-key"  http://localhost:3000/allowed
#> Successfully authenticated!

Key Extractors

The middleware extracts the API key from the request using an Extractor. You can specify one or more extractors in the configuration.

Built-in Extractors

The following extractors are available:

• keyauth.FromHeader(header string): Extracts the key from the specified header.
• keyauth.FromAuthHeader(header, authScheme string): Extracts the key from an authorization header (e.g., Authorization: Bearer <key>).
• keyauth.FromQuery(param string): Extracts the key from a URL query parameter.
• keyauth.FromParam(param string): Extracts the key from a URL path parameter.
• keyauth.FromCookie(name string): Extracts the key from a cookie.
• keyauth.FromForm(name string): Extracts the key from a form field.

Chaining Extractors

You can use keyauth.Chain to try multiple extractors until one succeeds. The first successful extraction is used.

// This will try to extract the key from:
// 1. The "X-API-Key" header
// 2. The "api_key" query parameter
app.Use(keyauth.New(keyauth.Config{
    Extractor: keyauth.Chain(
        keyauth.FromHeader("X-API-Key"),
        keyauth.FromQuery("api_key"),
    ),
    Validator: validateAPIKey,
}))

Config

Property	Type	Description	Default
Next	func(fiber.Ctx) bool	Next defines a function to skip this middleware when it returns true.	nil
SuccessHandler	fiber.Handler	SuccessHandler defines a function which is executed for a valid key.	c.Next()
ErrorHandler	fiber.ErrorHandler	ErrorHandler defines a function which is executed for an invalid key. By default a 401 response with a WWW-Authenticate challenge is sent.	Default error handler
Validator	func(fiber.Ctx, string) (bool, error)	Required. Validator is a function to validate the key.	nil (panic)
Extractor	keyauth.Extractor	Extractor defines how to retrieve the key from the request. Use helper functions like keyauth.FromAuthHeader or keyauth.FromCookie.	keyauth.FromAuthHeader("Authorization", "Bearer")
Realm	string	Realm specifies the protected area name used in the WWW-Authenticate header.	"Restricted"

Default Config

var ConfigDefault = Config{
    SuccessHandler: func(c fiber.Ctx) error {
        return c.Next()
    },
    ErrorHandler: func(c fiber.Ctx, _ error) error {
        return c.Status(fiber.StatusUnauthorized).SendString(ErrMissingOrMalformedAPIKey.Error())
    },
    Realm:     "Restricted",
    Extractor: FromAuthHeader(fiber.HeaderAuthorization, "Bearer"),
}