Go OpenID Connect (OIDC) HTTP Middleware

Introduction

This is a middleware for http to make it easy to use OpenID Connect.

Stability notice

This library is under active development and the api will have breaking changes until v0.1.0 - after that only breaking changes will be introduced between minor versions (v0.1.0 -> v0.2.0).

Currently tested providers

• Azure AD
• Auth0
• Okta
• Cognito

Currently Supported frameworks

• net/http, mux & chi
• gin
• fiber
• Echo (JWT ParseTokenFunc)
• Build your own middleware

Using options

Import: "github.com/xenitab/go-oidc-middleware/options"

net/http, mux & chi

Import

"github.com/xenitab/go-oidc-middleware/oidchttp"

Middleware

oidcHandler := oidchttp.New(h,
	options.WithIssuer(cfg.Issuer),
	options.WithRequiredTokenType("JWT"),
	options.WithRequiredAudience(cfg.Audience),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"tid": cfg.TenantID,
	}),
)

Handler

func newClaimsHandler() http.HandlerFunc {
	fn := func(w http.ResponseWriter, r *http.Request) {
		claims, ok := r.Context().Value(options.DefaultClaimsContextKeyName).(map[string]interface{})
		if !ok {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		err := json.NewEncoder(w).Encode(claims)
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
	}

	return http.HandlerFunc(fn)
}

gin

Import

"github.com/xenitab/go-oidc-middleware/oidcgin"

Middleware

oidcHandler := oidcgin.New(
	options.WithIssuer(cfg.Issuer),
	options.WithRequiredTokenType("JWT"),
	options.WithRequiredAudience(cfg.Audience),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"tid": cfg.TenantID,
	}),
)

Handler

func newClaimsHandler() gin.HandlerFunc {
	return func(c *gin.Context) {
		claimsValue, found := c.Get("claims")
		if !found {
			c.AbortWithStatus(http.StatusUnauthorized)
			return
		}

		claims, ok := claimsValue.(map[string]interface{})
		if !ok {
			c.AbortWithStatus(http.StatusUnauthorized)
			return
		}

		c.JSON(http.StatusOK, claims)
	}
}

fiber

Import

"github.com/xenitab/go-oidc-middleware/oidcfiber"

Middleware

oidcHandler := oidcfiber.New(
	options.WithIssuer(cfg.Issuer),
	options.WithRequiredTokenType("JWT"),
	options.WithRequiredAudience(cfg.Audience),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"tid": cfg.TenantID,
	}),
)

Handler

func newClaimsHandler() fiber.Handler {
	return func(c *fiber.Ctx) error {
		claims, ok := c.Locals("claims").(map[string]interface{})
		if !ok {
			return c.SendStatus(fiber.StatusUnauthorized)
		}

		return c.JSON(claims)
	}
}

Echo (JWT ParseTokenFunc)

Import

"github.com/xenitab/go-oidc-middleware/oidcechojwt"

Middleware

e.Use(middleware.JWTWithConfig(middleware.JWTConfig{
    ParseTokenFunc: oidcechojwt.New(
		options.WithIssuer(cfg.Issuer),
		options.WithRequiredTokenType("JWT"),
		options.WithRequiredAudience(cfg.Audience),
		options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
		options.WithRequiredClaims(map[string]interface{}{
			"tid": cfg.TenantID,
		}),
	),
}))

Handler

func newClaimsHandler(c echo.Context) error {
	claims, ok := c.Get("user").(map[string]interface{})
	if !ok {
		return echo.NewHTTPError(http.StatusUnauthorized, "invalid token")
	}

	return c.JSON(http.StatusOK, claims)
}

Build your own middleware

Import

"github.com/xenitab/go-oidc-middleware/oidctoken"

Example

oidcTokenHandler := oidctoken.New(h,
	options.WithIssuer(cfg.Issuer),
	options.WithRequiredTokenType("JWT"),
	options.WithRequiredAudience(cfg.Audience),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"tid": cfg.TenantID,
	}),
)

// oidctoken.GetTokenString is optional, but you will need the JWT token as a string
tokenString, err := oidctoken.GetTokenString(...)
if err != nil {
	panic(err)
}

token, err := oidcTokenHandler.ParseToken(ctx, tokenString)
if err != nil {
	panic(err)
}

Other options

Deeply nested required claims

If you want to use options.WithRequiredClaims() with nested values, you need to specify the actual type when configuring it and not an interface and the middleware will use this to infer what types the token claims are.

Example claims could look like this:

{
  "foo": {
    "bar": ["uno", "dos", "baz", "tres"]
  }
}

This would then be interpreted as the following inside the code:

"foo": map[string]interface {}{
	"bar":[]interface {}{
		"uno",
		"dos",
		"baz",
		"tres"
	},
}

If you want to require the claim foo.bar to contain the value baz, it would look like this:

options.WithRequiredClaims(map[string]interface{}{
	"foo": map[string][]string{
		"bar": {"baz"},
	}
})

Extract token from multiple headers

Example for Authorization and Foo headers. If token is found in Authorization, Foo will not be tried. If Authorization extraction fails but there's a header Foo = Bar_baz then baz would be extracted as the token.

oidcHandler := oidcgin.New(
	options.WithIssuer(cfg.Issuer),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"cid": cfg.ClientID,
	}),
	options.WithTokenString(
		options.WithTokenStringHeaderName("Authorization"),
		options.WithTokenStringTokenPrefix("Bearer "),
	),
	options.WithTokenString(
		options.WithTokenStringHeaderName("Foo"),
		options.WithTokenStringTokenPrefix("Bar_"),
	),
)

Manipulate the token string after extraction

If you want to do any kind of manipulation of the token string after extraction, the option WithTokenStringPostExtractionFn is available.

The following would be used by a the Kubernetes api server, where the kubernetes client can use both Authorization and Sec-WebSocket-Protocol.

oidcHandler := oidcgin.New(
	options.WithIssuer(cfg.Issuer),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"cid": cfg.ClientID,
	}),
	options.WithTokenString(
		options.WithTokenStringHeaderName("Authorization"),
		options.WithTokenStringTokenPrefix("Bearer "),
	),
	options.WithTokenString(
		options.WithTokenStringHeaderName("Sec-WebSocket-Protocol"),
		options.WithTokenStringTokenPrefix("base64url.bearer.authorization.k8s.io."),
		options.WithTokenStringListSeparator(","),
		options.WithTokenStringPostExtractionFn(func(s string) (string, error) {
			bytes, err := base64.RawStdEncoding.DecodeString(s)
			if err != nil {
				return "", err
			}

			return string(bytes), nil
		}),
	),
)

Custom error handler

It is possible to add a custom function to handle errors. It will not be possible to change anything using it, but you will be able to add logic for logging as an example.

errorHandler := func(description options.ErrorDescription, err error) {
	fmt.Printf("Description: %s\tError: %v\n", description, err)
}

oidcHandler := oidcgin.New(
	options.WithIssuer(cfg.Issuer),
	options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
	options.WithRequiredClaims(map[string]interface{}{
		"cid": cfg.ClientID,
	}),
	options.WithErrorHandler(errorHandler),
)

Testing with the middleware enabled

There's a small package that simulates an OpenID Provider that can be used with tests.

package main

import (
	"testing"

	"github.com/xenitab/go-oidc-middleware/optest"
)

func TestFoobar(t *testing.T) {
	op := optest.NewTesting(t)
	defer op.Close(t)

	[...]

	oidcHandler := oidchttp.New(h,
		options.WithIssuer(op.GetURL(t)),
		options.WithRequiredTokenType("JWT+AT"),
		options.WithRequiredAudience("test-client"),
	)

	token := op.GetToken(t)

	[...]

	token.SetAuthHeader(req)

	[...]
}

You can also configure multiple users by setting the following:

func TestFoobar(t *testing.T) {
	testUsers := map[string]TestUser{
		"test": {
			Audience:           "test-client",
			Subject:            "test",
			Name:               "Test Testersson",
			GivenName:          "Test",
			FamilyName:         "Testersson",
			Locale:             "en-US",
			Email:              "[email protected]",
			AccessTokenKeyType: "JWT+AT",
			IdTokenKeyType:     "JWT",
		},
		"foo": {
			Audience:           "foo-client",
			Subject:            "foo",
			Name:               "Foo Bar",
			GivenName:          "Foo",
			FamilyName:         "Bar",
			Locale:             "en-US",
			Email:              "[email protected]",
			AccessTokenKeyType: "JWT+AT",
			IdTokenKeyType:     "JWT",
		},
	}

	op := optest.NewTesting(t, optest.WithTestUsers(testUsers), optest.WithDefaultTestUser("test"))
	defer op.Close(t)

	[...]

	token1 := op.GetToken(t) // for user `test`
	token2 := op.GetTokenByUser(t, "test") // for user `test`
	token3 := op.GetTokenByUser(t, "foo") // for user `foo`
}

It is also possible to enable opaque access tokens with the option optest.WithOpaqueAccessTokens().

Examples

See examples readme for more information.

Roadmap

GitHub Project