README
¶
Go OpenID Connect (OIDC) HTTP Middleware
Introduction
This is a middleware for http to make it easy to use OpenID Connect.
Changelog
Below, large (breaking) changes will be documented:
v0.0.42
Error handlers now have access to the request and have full control over the HTTP response sent to the client. Among other things, this can be used to return structured error responses a la RFC7807. However, this comes with a breaking interface change: error handler contract changes from type ErrorHandler func(description ErrorDescription, err error) to errorHandler(ctx context.Context, oidcErr *options.OidcError) *options.Response. To retain the behavior of your error handler, update your error handler signature accordingly, change description to oidcErr.Status, err to oidcErr.Error and add an explicit return nil.
v0.0.41
The oidcechojwt adapter is replaced by oidcecho which brings in line with the other adapters in that it operates as a ordinary middleware. This makes all adapters full HTTP middlewares. That makes it easier to add new features, such as the the upcoming error handling changes. The new adapter provides identical features.
v0.0.37
From v0.0.37 and forward, the options.WithRequiredClaims() has been deprecated and generics are used to provide the claims type. A new validation function can be provided instead of options.WithRequiredClaims(). If you don't need claims validation, you can pass nil instead of a ClaimsValidationFn.
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
Using options
Import: "github.com/xenitab/go-oidc-middleware/options"
Claims validation example
From v0.0.37 and forward, claim validation is done using a ClaimsValidationFn. The below examples will use the following claims type and validation function:
type AzureADClaims struct {
Aio string `json:"aio"`
Audience []string `json:"aud"`
Azp string `json:"azp"`
Azpacr string `json:"azpacr"`
ExpiresAt time.Time `json:"exp"`
IssuedAt time.Time `json:"iat"`
Idp string `json:"idp"`
Issuer string `json:"iss"`
Name string `json:"name"`
NotBefore time.Time `json:"nbf"`
Oid string `json:"oid"`
PreferredUsername string `json:"preferred_username"`
Rh string `json:"rh"`
Scope string `json:"scp"`
Subject string `json:"sub"`
TenantId string `json:"tid"`
Uti string `json:"uti"`
TokenVersion string `json:"ver"`
}
func GetAzureADClaimsValidationFn(requiredTenantId string) options.ClaimsValidationFn[AzureADClaims] {
return func(claims *AzureADClaims) error {
if requiredTenantId != "" && claims.TenantId != requiredTenantId {
return fmt.Errorf("tid claim is required to be %q but was: %s", requiredTenantId, claims.TenantId)
}
return nil
}
}
If you don't want typed claims, use type Claims map[string]interface{} and provide it. If you don't want to use a ClaimsValidationFn (as it will provide the type) the handlers will need to be configured as below:
type Claims map[string]interface{}
oidcHandler := oidchttp.New[Claims](h, nil, opts...)
or
oidcHandler := oidchttp.New[map[string]interface{}](h, nil, opts...)
net/http, mux & chi
Import
"github.com/xenitab/go-oidc-middleware/oidchttp"
Middleware
oidcHandler := oidchttp.New(h,
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithRequiredTokenType("JWT"),
options.WithRequiredAudience(cfg.Audience),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
)
Handler
func newClaimsHandler() http.HandlerFunc {
fn := func(w http.ResponseWriter, r *http.Request) {
claims, ok := r.Context().Value(options.DefaultClaimsContextKeyName).(AzureADClaims)
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(
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithRequiredTokenType("JWT"),
options.WithRequiredAudience(cfg.Audience),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
)
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.(AzureADClaims)
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(
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithRequiredTokenType("JWT"),
options.WithRequiredAudience(cfg.Audience),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
)
Handler
func newClaimsHandler() fiber.Handler {
return func(c *fiber.Ctx) error {
claims, ok := c.Locals("claims").(AzureADClaims)
if !ok {
return c.SendStatus(fiber.StatusUnauthorized)
}
return c.JSON(claims)
}
}
Echo
Import
"github.com/xenitab/go-oidc-middleware/oidcecho"
Middleware
oidcHandler := oidcecho.New(
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithRequiredTokenType("JWT"),
options.WithRequiredAudience(cfg.Audience),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
)
Handler
func newClaimsHandler(c echo.Context) error {
claims, ok := c.Get("user").(AzureADClaims)
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,
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithRequiredTokenType("JWT"),
options.WithRequiredAudience(cfg.Audience),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
)
// 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
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(
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
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(
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
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. The error handler can return an options.Response which will be rendered by the middleware. Returning nil will result in a default 400/401 error.
type Message struct {
Message string `json:"message"`
Url string `json:"url"`
}
func errorHandler(ctx context.Context, oidcErr *options.OidcError) *options.Response {
message := Message{
Message: string(oidcErr.Status),
Url: oidcErr.Url.String(),
}
var headers map[string]string
json, err := json.Marshal(message)
if err != nil {
headers["Content-Type"] = "text/plain"
return &options.Response{
StatusCode: 500,
Headers: headers,
Body: []byte("Internal encoding failure\r\n"),
}
}
headers["Content-Type"] = "text/plain"
return &options.Response{
StatusCode: 418,
Headers: headers,
Body: json,
}
}
oidcHandler := oidcgin.New(
GetAzureADClaimsValidationFn(cfg.TenantID),
options.WithIssuer(cfg.Issuer),
options.WithFallbackSignatureAlgorithm(cfg.FallbackSignatureAlgorithm),
options.WithErrorHandler(errorHandler),
)
This error handling interface was changed in v0.0.42. The previous interface was func(description ErrorDescription, err error). In order to retain the same behavior, you need to update your error handler to read desctiption and err from oidcErr and return nil.
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,
GetAzureADClaimsValidationFn(cfg.TenantID),
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: "test@testersson.com",
AccessTokenKeyType: "JWT+AT",
IdTokenKeyType: "JWT",
},
"foo": {
Audience: "foo-client",
Subject: "foo",
Name: "Foo Bar",
GivenName: "Foo",
FamilyName: "Bar",
Locale: "en-US",
Email: "foo@bar.com",
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(). If you add optest.WithLoginPrompt() you will have a simple HTML page with the different test users to choose from when going to /authorization.
Examples
See examples readme for more information.
Directories