feat(op): dynamic issuer depending on request / host

BREAKING CHANGE: The OpenID Provider package is now able to handle multiple issuers with a single storage implementation. The issuer will be selected from the host of the request and passed into the context, where every function can read it from if necessary. This results in some fundamental changes: - `Configuration` interface: - `Issuer() string` has been changed to `IssuerFromRequest(r *http.Request) string` - `Insecure() bool` has been added - OpenIDProvider interface and dependants: - `Issuer` has been removed from Config struct - `NewOpenIDProvider` now takes an additional parameter `issuer` and returns a pointer to the public/default implementation and not an OpenIDProvider interface: `NewOpenIDProvider(ctx context.Context, config *Config, storage Storage, opOpts ...Option) (OpenIDProvider, error)` changed to `NewOpenIDProvider(ctx context.Context, issuer string, config *Config, storage Storage, opOpts ...Option) (*Provider, error)` - therefore the parameter type Option changed to the public type as well: `Option func(o *Provider) error` - `AuthCallbackURL(o OpenIDProvider) func(string) string` has been changed to `AuthCallbackURL(o OpenIDProvider) func(context.Context, string) string` - `IDTokenHintVerifier() IDTokenHintVerifier` (Authorizer, OpenIDProvider, SessionEnder interfaces), `AccessTokenVerifier() AccessTokenVerifier` (Introspector, OpenIDProvider, Revoker, UserinfoProvider interfaces) and `JWTProfileVerifier() JWTProfileVerifier` (IntrospectorJWTProfile, JWTAuthorizationGrantExchanger, OpenIDProvider, RevokerJWTProfile interfaces) now take a context.Context parameter `IDTokenHintVerifier(context.Context) IDTokenHintVerifier`, `AccessTokenVerifier(context.Context) AccessTokenVerifier` and `JWTProfileVerifier(context.Context) JWTProfileVerifier` - `OidcDevMode` (CAOS_OIDC_DEV) environment variable check has been removed, use `WithAllowInsecure()` Option - Signing: the signer is not kept in memory anymore, but created on request from the loaded key: - `Signer` interface and func `NewSigner` have been removed - `ReadySigner(s Signer) ProbesFn` has been removed - `CreateDiscoveryConfig(c Configuration, s Signer) *oidc.DiscoveryConfiguration` has been changed to `CreateDiscoveryConfig(r *http.Request, config Configuration, storage DiscoverStorage) *oidc.DiscoveryConfiguration` - `Storage` interface: - `GetSigningKey(context.Context, chan<- jose.SigningKey)` has been changed to `SigningKey(context.Context) (SigningKey, error)` - `KeySet(context.Context) ([]Key, error)` has been added - `GetKeySet(context.Context) (*jose.JSONWebKeySet, error)` has been changed to `KeySet(context.Context) ([]Key, error)` - `SigAlgorithms(s Signer) []string` has been changed to `SigAlgorithms(ctx context.Context, storage DiscoverStorage) []string` - KeyProvider interface: `GetKeySet(context.Context) (*jose.JSONWebKeySet, error)` has been changed to `KeySet(context.Context) ([]Key, error)` - `CreateIDToken`: the Signer parameter has been removed
2022-04-19 14:33:07 +02:00 · 2022-04-19 14:33:07 +02:00 · a27ba09872
commit a27ba09872
parent 885fe0d45c
33 changed files with 1504 additions and 657 deletions
--- a/pkg/op/auth_request.go
+++ b/pkg/op/auth_request.go
@ -37,10 +37,8 @@ type Authorizer interface {
 	Storage() Storage
 	Decoder() httphelper.Decoder
 	Encoder() httphelper.Encoder
-	Signer() Signer
-	IDTokenHintVerifier() IDTokenHintVerifier
+	IDTokenHintVerifier(context.Context) IDTokenHintVerifier
 	Crypto() Crypto
-	Issuer() string
 	RequestObjectSupported() bool
 }

@ -71,8 +69,9 @@ func Authorize(w http.ResponseWriter, r *http.Request, authorizer Authorizer) {
 		AuthRequestError(w, r, authReq, err, authorizer.Encoder())
 		return
 	}
+	ctx := r.Context()
 	if authReq.RequestParam != "" && authorizer.RequestObjectSupported() {
-		authReq, err = ParseRequestObject(r.Context(), authReq, authorizer.Storage(), authorizer.Issuer())
+		authReq, err = ParseRequestObject(ctx, authReq, authorizer.Storage(), IssuerFromContext(ctx))
 		if err != nil {
 			AuthRequestError(w, r, authReq, err, authorizer.Encoder())
 			return
@ -82,7 +81,7 @@ func Authorize(w http.ResponseWriter, r *http.Request, authorizer Authorizer) {
 	if validater, ok := authorizer.(AuthorizeValidator); ok {
 		validation = validater.ValidateAuthRequest
 	}
-	userID, err := validation(r.Context(), authReq, authorizer.Storage(), authorizer.IDTokenHintVerifier())
+	userID, err := validation(ctx, authReq, authorizer.Storage(), authorizer.IDTokenHintVerifier(ctx))
 	if err != nil {
 		AuthRequestError(w, r, authReq, err, authorizer.Encoder())
 		return
@ -91,12 +90,12 @@ func Authorize(w http.ResponseWriter, r *http.Request, authorizer Authorizer) {
 		AuthRequestError(w, r, authReq, oidc.ErrRequestNotSupported(), authorizer.Encoder())
 		return
 	}
-	req, err := authorizer.Storage().CreateAuthRequest(r.Context(), authReq, userID)
+	req, err := authorizer.Storage().CreateAuthRequest(ctx, authReq, userID)
 	if err != nil {
 		AuthRequestError(w, r, authReq, oidc.DefaultToServerError(err, "unable to save auth request"), authorizer.Encoder())
 		return
 	}
-	client, err := authorizer.Storage().GetClientByClientID(r.Context(), req.GetClientID())
+	client, err := authorizer.Storage().GetClientByClientID(ctx, req.GetClientID())
 	if err != nil {
 		AuthRequestError(w, r, req, oidc.DefaultToServerError(err, "unable to retrieve client by id"), authorizer.Encoder())
 		return
--- a/pkg/op/config.go
+++ b/pkg/op/config.go
@ -2,16 +2,24 @@ package op

 import (
 	"errors"
+	"net/http"
 	"net/url"
-	"os"
+	"strings"

 	"golang.org/x/text/language"
 )

-const OidcDevMode = "CAOS_OIDC_DEV"
+var (
+	ErrInvalidIssuerPath        = errors.New("no fragments or query allowed for issuer")
+	ErrInvalidIssuerNoIssuer    = errors.New("missing issuer")
+	ErrInvalidIssuerURL         = errors.New("invalid url for issuer")
+	ErrInvalidIssuerMissingHost = errors.New("host for issuer missing")
+	ErrInvalidIssuerHTTPS       = errors.New("scheme for issuer must be `https`")
+)

 type Configuration interface {
-	Issuer() string
+	IssuerFromRequest(r *http.Request) string
+	Insecure() bool
 	AuthorizationEndpoint() Endpoint
 	TokenEndpoint() Endpoint
 	IntrospectionEndpoint() Endpoint
@ -37,32 +45,74 @@ type Configuration interface {
 	SupportedUILocales() []language.Tag
 }

-func ValidateIssuer(issuer string) error {
+type IssuerFromRequest func(r *http.Request) string
+
+func IssuerFromHost(path string) func(bool) (IssuerFromRequest, error) {
+	return func(allowInsecure bool) (IssuerFromRequest, error) {
+		issuerPath, err := url.Parse(path)
+		if err != nil {
+			return nil, ErrInvalidIssuerURL
+		}
+		if err := ValidateIssuerPath(issuerPath); err != nil {
+			return nil, err
+		}
+		return func(r *http.Request) string {
+			return dynamicIssuer(r.Host, path, allowInsecure)
+		}, nil
+	}
+}
+
+func StaticIssuer(issuer string) func(bool) (IssuerFromRequest, error) {
+	return func(allowInsecure bool) (IssuerFromRequest, error) {
+		if err := ValidateIssuer(issuer, allowInsecure); err != nil {
+			return nil, err
+		}
+		return func(_ *http.Request) string {
+			return issuer
+		}, nil
+	}
+}
+
+func ValidateIssuer(issuer string, allowInsecure bool) error {
 	if issuer == "" {
-		return errors.New("missing issuer")
+		return ErrInvalidIssuerNoIssuer
 	}
 	u, err := url.Parse(issuer)
 	if err != nil {
-		return errors.New("invalid url for issuer")
+		return ErrInvalidIssuerURL
 	}
 	if u.Host == "" {
-		return errors.New("host for issuer missing")
+		return ErrInvalidIssuerMissingHost
 	}
 	if u.Scheme != "https" {
-		if !devLocalAllowed(u) {
-			return errors.New("scheme for issuer must be `https`")
+		if !devLocalAllowed(u, allowInsecure) {
+			return ErrInvalidIssuerHTTPS
 		}
 	}
-	if u.Fragment != "" || len(u.Query()) > 0 {
-		return errors.New("no fragments or query allowed for issuer")
+	return ValidateIssuerPath(u)
+}
+
+func ValidateIssuerPath(issuer *url.URL) error {
+	if issuer.Fragment != "" || len(issuer.Query()) > 0 {
+		return ErrInvalidIssuerPath
 	}
 	return nil
 }

-func devLocalAllowed(url *url.URL) bool {
-	_, b := os.LookupEnv(OidcDevMode)
-	if !b {
-		return b
+func devLocalAllowed(url *url.URL, allowInsecure bool) bool {
+	if !allowInsecure {
+		return false
 	}
 	return url.Scheme == "http"
 }
+
+func dynamicIssuer(issuer, path string, allowInsecure bool) string {
+	schema := "https"
+	if allowInsecure {
+		schema = "http"
+	}
+	if len(path) > 0 && !strings.HasPrefix(path, "/") {
+		path = "/" + path
+	}
+	return schema + "://" + issuer + path
+}
--- a/pkg/op/config_test.go
+++ b/pkg/op/config_test.go
@ -1,13 +1,17 @@
 package op

 import (
-	"os"
+	"net/http/httptest"
+	"net/url"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )

 func TestValidateIssuer(t *testing.T) {
 	type args struct {
-		issuer string
+		issuer        string
+		allowInsecure bool
 	}
 	tests := []struct {
 		name    string
@ -16,65 +20,97 @@ func TestValidateIssuer(t *testing.T) {
 	}{
 		{
 			"missing issuer fails",
-			args{""},
+			args{
+				issuer: "",
+			},
 			true,
 		},
 		{
 			"invalid url for issuer fails",
-			args{":issuer"},
-			true,
-		},
-		{
-			"invalid url for issuer fails",
-			args{":issuer"},
+			args{
+				issuer: ":issuer",
+			},
 			true,
 		},
 		{
 			"host for issuer missing fails",
-			args{"https:///issuer"},
-			true,
-		},
-		{
-			"host for not https fails",
-			args{"http://issuer.com"},
+			args{
+				issuer: "https:///issuer",
+			},
 			true,
 		},
 		{
 			"host with fragment fails",
-			args{"https://issuer.com/#issuer"},
+			args{
+				issuer: "https://issuer.com/#issuer",
+			},
 			true,
 		},
 		{
 			"host with query fails",
-			args{"https://issuer.com?issuer=me"},
+			args{
+				issuer: "https://issuer.com?issuer=me",
+			},
+			true,
+		},
+		{
+			"host with http fails",
+			args{
+				issuer: "http://issuer.com",
+			},
 			true,
 		},
 		{
 			"host with https ok",
-			args{"https://issuer.com"},
+			args{
+				issuer: "https://issuer.com",
+			},
 			false,
 		},
 		{
-			"localhost with http fails",
-			args{"http://localhost:9999"},
+			"custom scheme fails",
+			args{
+				issuer: "custom://localhost:9999",
+			},
+			true,
+		},
+		{
+			"http with allowInsecure ok",
+			args{
+				issuer:        "http://localhost:9999",
+				allowInsecure: true,
+			},
+			false,
+		},
+		{
+			"https with allowInsecure ok",
+			args{
+				issuer:        "https://localhost:9999",
+				allowInsecure: true,
+			},
+			false,
+		},
+		{
+			"custom scheme with allowInsecure fails",
+			args{
+				issuer:        "custom://localhost:9999",
+				allowInsecure: true,
+			},
 			true,
 		},
 	}
-	//ensure env is not set
-	//nolint:errcheck
-	os.Unsetenv(OidcDevMode)
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if err := ValidateIssuer(tt.args.issuer); (err != nil) != tt.wantErr {
+			if err := ValidateIssuer(tt.args.issuer, tt.args.allowInsecure); (err != nil) != tt.wantErr {
 				t.Errorf("ValidateIssuer() error = %v, wantErr %v", err, tt.wantErr)
 			}
 		})
 	}
 }

-func TestValidateIssuerDevLocalAllowed(t *testing.T) {
+func TestValidateIssuerPath(t *testing.T) {
 	type args struct {
-		issuer string
+		issuerPath *url.URL
 	}
 	tests := []struct {
 		name    string
@ -82,17 +118,217 @@ func TestValidateIssuerDevLocalAllowed(t *testing.T) {
 		wantErr bool
 	}{
 		{
-			"localhost with http with dev ok",
-			args{"http://localhost:9999"},
+			"empty ok",
+			args{func() *url.URL {
+				u, _ := url.Parse("")
+				return u
+			}()},
 			false,
 		},
+		{
+			"custom ok",
+			args{func() *url.URL {
+				u, _ := url.Parse("/custom")
+				return u
+			}()},
+			false,
+		},
+		{
+			"fragment fails",
+			args{func() *url.URL {
+				u, _ := url.Parse("#fragment")
+				return u
+			}()},
+			true,
+		},
+		{
+			"query fails",
+			args{func() *url.URL {
+				u, _ := url.Parse("?query=value")
+				return u
+			}()},
+			true,
+		},
 	}
-	//nolint:errcheck
-	os.Setenv(OidcDevMode, "true")
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if err := ValidateIssuer(tt.args.issuer); (err != nil) != tt.wantErr {
-				t.Errorf("ValidateIssuer() error = %v, wantErr %v", err, tt.wantErr)
+			if err := ValidateIssuerPath(tt.args.issuerPath); (err != nil) != tt.wantErr {
+				t.Errorf("ValidateIssuerPath() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestIssuerFromHost(t *testing.T) {
+	type args struct {
+		path          string
+		allowInsecure bool
+		target        string
+	}
+	type res struct {
+		issuer string
+		err    error
+	}
+	tests := []struct {
+		name string
+		args args
+		res  res
+	}{
+		{
+			"invalid issuer path",
+			args{
+				path:          "/#fragment",
+				allowInsecure: false,
+			},
+			res{
+				issuer: "",
+				err:    ErrInvalidIssuerPath,
+			},
+		},
+		{
+			"empty path secure",
+			args{
+				path:          "",
+				allowInsecure: false,
+				target:        "https://issuer.com",
+			},
+			res{
+				issuer: "https://issuer.com",
+				err:    nil,
+			},
+		},
+		{
+			"custom path secure",
+			args{
+				path:          "/custom/",
+				allowInsecure: false,
+				target:        "https://issuer.com",
+			},
+			res{
+				issuer: "https://issuer.com/custom/",
+				err:    nil,
+			},
+		},
+		{
+			"custom path no leading slash",
+			args{
+				path:          "custom/",
+				allowInsecure: false,
+				target:        "https://issuer.com",
+			},
+			res{
+				issuer: "https://issuer.com/custom/",
+				err:    nil,
+			},
+		},
+		{
+			"empty path unsecure",
+			args{
+				path:          "",
+				allowInsecure: true,
+				target:        "http://issuer.com",
+			},
+			res{
+				issuer: "http://issuer.com",
+				err:    nil,
+			},
+		},
+		{
+			"custom path unsecure",
+			args{
+				path:          "/custom/",
+				allowInsecure: true,
+				target:        "http://issuer.com",
+			},
+			res{
+				issuer: "http://issuer.com/custom/",
+				err:    nil,
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			issuer, err := IssuerFromHost(tt.args.path)(tt.args.allowInsecure)
+			if tt.res.err == nil {
+				assert.NoError(t, err)
+				req := httptest.NewRequest("", tt.args.target, nil)
+				assert.Equal(t, tt.res.issuer, issuer(req))
+			}
+			if tt.res.err != nil {
+				assert.ErrorIs(t, err, tt.res.err)
+			}
+		})
+	}
+}
+
+func TestStaticIssuer(t *testing.T) {
+	type args struct {
+		issuer        string
+		allowInsecure bool
+	}
+	type res struct {
+		issuer string
+		err    error
+	}
+	tests := []struct {
+		name string
+		args args
+		res  res
+	}{
+		{
+			"invalid issuer",
+			args{
+				issuer:        "",
+				allowInsecure: false,
+			},
+			res{
+				issuer: "",
+				err:    ErrInvalidIssuerNoIssuer,
+			},
+		},
+		{
+			"empty path secure",
+			args{
+				issuer:        "https://issuer.com",
+				allowInsecure: false,
+			},
+			res{
+				issuer: "https://issuer.com",
+				err:    nil,
+			},
+		},
+		{
+			"custom path secure",
+			args{
+				issuer:        "https://issuer.com/custom/",
+				allowInsecure: false,
+			},
+			res{
+				issuer: "https://issuer.com/custom/",
+				err:    nil,
+			},
+		},
+		{
+			"unsecure",
+			args{
+				issuer:        "http://issuer.com",
+				allowInsecure: true,
+			},
+			res{
+				issuer: "http://issuer.com",
+				err:    nil,
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			issuer, err := StaticIssuer(tt.args.issuer)(tt.args.allowInsecure)
+			if tt.res.err == nil {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.res.issuer, issuer(nil))
+			}
+			if tt.res.err != nil {
+				assert.ErrorIs(t, err, tt.res.err)
 			}
 		})
 	}
--- a/pkg/op/context.go
+++ b/pkg/op/context.go
@ -0,0 +1,49 @@
+package op
+
+import (
+	"context"
+	"net/http"
+)
+
+type key int
+
+var (
+	issuer key = 0
+)
+
+type IssuerInterceptor struct {
+	issuerFromRequest IssuerFromRequest
+}
+
+//NewIssuerInterceptor will set the issuer into the context
+//by the provided IssuerFromRequest (e.g. returned from StaticIssuer or IssuerFromHost)
+func NewIssuerInterceptor(issuerFromRequest IssuerFromRequest) *IssuerInterceptor {
+	return &IssuerInterceptor{
+		issuerFromRequest: issuerFromRequest,
+	}
+}
+
+func (i *IssuerInterceptor) Handler(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		i.setIssuerCtx(w, r, next)
+	})
+}
+
+func (i *IssuerInterceptor) HandlerFunc(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		i.setIssuerCtx(w, r, next)
+	}
+}
+
+//IssuerFromContext reads the issuer from the context (set by an IssuerInterceptor)
+//it will return an empty string if not found
+func IssuerFromContext(ctx context.Context) string {
+	ctxIssuer, _ := ctx.Value(issuer).(string)
+	return ctxIssuer
+}
+
+func (i *IssuerInterceptor) setIssuerCtx(w http.ResponseWriter, r *http.Request, next http.Handler) {
+	ctx := context.WithValue(r.Context(), issuer, i.issuerFromRequest(r))
+	r = r.WithContext(ctx)
+	next.ServeHTTP(w, r)
+}
--- a/pkg/op/context_test.go
+++ b/pkg/op/context_test.go
@ -0,0 +1,76 @@
+package op
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIssuerInterceptor(t *testing.T) {
+	type fields struct {
+		issuerFromRequest IssuerFromRequest
+	}
+	type args struct {
+		r    *http.Request
+		next http.Handler
+	}
+	type res struct {
+		issuer string
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		args   args
+		res    res
+	}{
+		{
+			"empty",
+			fields{
+				func(r *http.Request) string {
+					return ""
+				},
+			},
+			args{},
+			res{
+				issuer: "",
+			},
+		},
+		{
+			"static",
+			fields{
+				func(r *http.Request) string {
+					return "static"
+				},
+			},
+			args{},
+			res{
+				issuer: "static",
+			},
+		},
+		{
+			"host",
+			fields{
+				func(r *http.Request) string {
+					return r.Host
+				},
+			},
+			args{},
+			res{
+				issuer: "issuer.com",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			i := NewIssuerInterceptor(tt.fields.issuerFromRequest)
+			next := http.HandlerFunc(func(_ http.ResponseWriter, r *http.Request) {
+				assert.Equal(t, tt.res.issuer, IssuerFromContext(r.Context()))
+			})
+			req := httptest.NewRequest("", "https://issuer.com", nil)
+			i.Handler(next).ServeHTTP(nil, req)
+			i.HandlerFunc(next).ServeHTTP(nil, req)
+		})
+	}
+}
--- a/pkg/op/discovery.go
+++ b/pkg/op/discovery.go
@ -1,49 +1,17 @@
 package op

 import (
+	"context"
 	"net/http"

+	"gopkg.in/square/go-jose.v2"
+
 	httphelper "github.com/caos/oidc/pkg/http"
 	"github.com/caos/oidc/pkg/oidc"
 )

-func discoveryHandler(c Configuration, s Signer) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
-		Discover(w, CreateDiscoveryConfig(c, s))
-	}
-}
-
-func Discover(w http.ResponseWriter, config *oidc.DiscoveryConfiguration) {
-	httphelper.MarshalJSON(w, config)
-}
-
-func CreateDiscoveryConfig(c Configuration, s Signer) *oidc.DiscoveryConfiguration {
-	return &oidc.DiscoveryConfiguration{
-		Issuer:                                     c.Issuer(),
-		AuthorizationEndpoint:                      c.AuthorizationEndpoint().Absolute(c.Issuer()),
-		TokenEndpoint:                              c.TokenEndpoint().Absolute(c.Issuer()),
-		IntrospectionEndpoint:                      c.IntrospectionEndpoint().Absolute(c.Issuer()),
-		UserinfoEndpoint:                           c.UserinfoEndpoint().Absolute(c.Issuer()),
-		RevocationEndpoint:                         c.RevocationEndpoint().Absolute(c.Issuer()),
-		EndSessionEndpoint:                         c.EndSessionEndpoint().Absolute(c.Issuer()),
-		JwksURI:                                    c.KeysEndpoint().Absolute(c.Issuer()),
-		ScopesSupported:                            Scopes(c),
-		ResponseTypesSupported:                     ResponseTypes(c),
-		GrantTypesSupported:                        GrantTypes(c),
-		SubjectTypesSupported:                      SubjectTypes(c),
-		IDTokenSigningAlgValuesSupported:           SigAlgorithms(s),
-		RequestObjectSigningAlgValuesSupported:     RequestObjectSigAlgorithms(c),
-		TokenEndpointAuthMethodsSupported:          AuthMethodsTokenEndpoint(c),
-		TokenEndpointAuthSigningAlgValuesSupported: TokenSigAlgorithms(c),
-		IntrospectionEndpointAuthSigningAlgValuesSupported: IntrospectionSigAlgorithms(c),
-		IntrospectionEndpointAuthMethodsSupported:          AuthMethodsIntrospectionEndpoint(c),
-		RevocationEndpointAuthSigningAlgValuesSupported:    RevocationSigAlgorithms(c),
-		RevocationEndpointAuthMethodsSupported:             AuthMethodsRevocationEndpoint(c),
-		ClaimsSupported:                                    SupportedClaims(c),
-		CodeChallengeMethodsSupported:                      CodeChallengeMethods(c),
-		UILocalesSupported:                                 c.SupportedUILocales(),
-		RequestParameterSupported:                          c.RequestObjectSupported(),
-	}
+type DiscoverStorage interface {
+	SignatureAlgorithms(context.Context) ([]jose.SignatureAlgorithm, error)
 }

 var DefaultSupportedScopes = []string{
@ -55,6 +23,46 @@ var DefaultSupportedScopes = []string{
 	oidc.ScopeOfflineAccess,
 }

+func discoveryHandler(c Configuration, s DiscoverStorage) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		Discover(w, CreateDiscoveryConfig(r, c, s))
+	}
+}
+
+func Discover(w http.ResponseWriter, config *oidc.DiscoveryConfiguration) {
+	httphelper.MarshalJSON(w, config)
+}
+
+func CreateDiscoveryConfig(r *http.Request, config Configuration, storage DiscoverStorage) *oidc.DiscoveryConfiguration {
+	issuer := config.IssuerFromRequest(r)
+	return &oidc.DiscoveryConfiguration{
+		Issuer:                                     issuer,
+		AuthorizationEndpoint:                      config.AuthorizationEndpoint().Absolute(issuer),
+		TokenEndpoint:                              config.TokenEndpoint().Absolute(issuer),
+		IntrospectionEndpoint:                      config.IntrospectionEndpoint().Absolute(issuer),
+		UserinfoEndpoint:                           config.UserinfoEndpoint().Absolute(issuer),
+		RevocationEndpoint:                         config.RevocationEndpoint().Absolute(issuer),
+		EndSessionEndpoint:                         config.EndSessionEndpoint().Absolute(issuer),
+		JwksURI:                                    config.KeysEndpoint().Absolute(issuer),
+		ScopesSupported:                            Scopes(config),
+		ResponseTypesSupported:                     ResponseTypes(config),
+		GrantTypesSupported:                        GrantTypes(config),
+		SubjectTypesSupported:                      SubjectTypes(config),
+		IDTokenSigningAlgValuesSupported:           SigAlgorithms(r.Context(), storage),
+		RequestObjectSigningAlgValuesSupported:     RequestObjectSigAlgorithms(config),
+		TokenEndpointAuthMethodsSupported:          AuthMethodsTokenEndpoint(config),
+		TokenEndpointAuthSigningAlgValuesSupported: TokenSigAlgorithms(config),
+		IntrospectionEndpointAuthSigningAlgValuesSupported: IntrospectionSigAlgorithms(config),
+		IntrospectionEndpointAuthMethodsSupported:          AuthMethodsIntrospectionEndpoint(config),
+		RevocationEndpointAuthSigningAlgValuesSupported:    RevocationSigAlgorithms(config),
+		RevocationEndpointAuthMethodsSupported:             AuthMethodsRevocationEndpoint(config),
+		ClaimsSupported:                                    SupportedClaims(config),
+		CodeChallengeMethodsSupported:                      CodeChallengeMethods(config),
+		UILocalesSupported:                                 config.SupportedUILocales(),
+		RequestParameterSupported:                          config.RequestObjectSupported(),
+	}
+}
+
 func Scopes(c Configuration) []string {
 	return DefaultSupportedScopes //TODO: config
 }
@ -84,6 +92,88 @@ func GrantTypes(c Configuration) []oidc.GrantType {
 	return grantTypes
 }

+func SubjectTypes(c Configuration) []string {
+	return []string{"public"} //TODO: config
+}
+
+func SigAlgorithms(ctx context.Context, storage DiscoverStorage) []string {
+	algorithms, err := storage.SignatureAlgorithms(ctx)
+	if err != nil {
+		return nil
+	}
+	algs := make([]string, len(algorithms))
+	for i, algorithm := range algorithms {
+		algs[i] = string(algorithm)
+	}
+	return algs
+}
+
+func RequestObjectSigAlgorithms(c Configuration) []string {
+	if !c.RequestObjectSupported() {
+		return nil
+	}
+	return c.RequestObjectSigningAlgorithmsSupported()
+}
+
+func AuthMethodsTokenEndpoint(c Configuration) []oidc.AuthMethod {
+	authMethods := []oidc.AuthMethod{
+		oidc.AuthMethodNone,
+		oidc.AuthMethodBasic,
+	}
+	if c.AuthMethodPostSupported() {
+		authMethods = append(authMethods, oidc.AuthMethodPost)
+	}
+	if c.AuthMethodPrivateKeyJWTSupported() {
+		authMethods = append(authMethods, oidc.AuthMethodPrivateKeyJWT)
+	}
+	return authMethods
+}
+
+func TokenSigAlgorithms(c Configuration) []string {
+	if !c.AuthMethodPrivateKeyJWTSupported() {
+		return nil
+	}
+	return c.TokenEndpointSigningAlgorithmsSupported()
+}
+
+func IntrospectionSigAlgorithms(c Configuration) []string {
+	if !c.IntrospectionAuthMethodPrivateKeyJWTSupported() {
+		return nil
+	}
+	return c.IntrospectionEndpointSigningAlgorithmsSupported()
+}
+
+func AuthMethodsIntrospectionEndpoint(c Configuration) []oidc.AuthMethod {
+	authMethods := []oidc.AuthMethod{
+		oidc.AuthMethodBasic,
+	}
+	if c.AuthMethodPrivateKeyJWTSupported() {
+		authMethods = append(authMethods, oidc.AuthMethodPrivateKeyJWT)
+	}
+	return authMethods
+}
+
+func RevocationSigAlgorithms(c Configuration) []string {
+	if !c.RevocationAuthMethodPrivateKeyJWTSupported() {
+		return nil
+	}
+	return c.RevocationEndpointSigningAlgorithmsSupported()
+}
+
+func AuthMethodsRevocationEndpoint(c Configuration) []oidc.AuthMethod {
+	authMethods := []oidc.AuthMethod{
+		oidc.AuthMethodNone,
+		oidc.AuthMethodBasic,
+	}
+	if c.AuthMethodPostSupported() {
+		authMethods = append(authMethods, oidc.AuthMethodPost)
+	}
+	if c.AuthMethodPrivateKeyJWTSupported() {
+		authMethods = append(authMethods, oidc.AuthMethodPrivateKeyJWT)
+	}
+	return authMethods
+}
+
 func SupportedClaims(c Configuration) []string {
 	return []string{ //TODO: config
 		"sub",
@ -113,59 +203,6 @@ func SupportedClaims(c Configuration) []string {
 	}
 }

-func SigAlgorithms(s Signer) []string {
-	return []string{string(s.SignatureAlgorithm())}
-}
-
-func SubjectTypes(c Configuration) []string {
-	return []string{"public"} //TODO: config
-}
-
-func AuthMethodsTokenEndpoint(c Configuration) []oidc.AuthMethod {
-	authMethods := []oidc.AuthMethod{
-		oidc.AuthMethodNone,
-		oidc.AuthMethodBasic,
-	}
-	if c.AuthMethodPostSupported() {
-		authMethods = append(authMethods, oidc.AuthMethodPost)
-	}
-	if c.AuthMethodPrivateKeyJWTSupported() {
-		authMethods = append(authMethods, oidc.AuthMethodPrivateKeyJWT)
-	}
-	return authMethods
-}
-
-func TokenSigAlgorithms(c Configuration) []string {
-	if !c.AuthMethodPrivateKeyJWTSupported() {
-		return nil
-	}
-	return c.TokenEndpointSigningAlgorithmsSupported()
-}
-
-func AuthMethodsIntrospectionEndpoint(c Configuration) []oidc.AuthMethod {
-	authMethods := []oidc.AuthMethod{
-		oidc.AuthMethodBasic,
-	}
-	if c.AuthMethodPrivateKeyJWTSupported() {
-		authMethods = append(authMethods, oidc.AuthMethodPrivateKeyJWT)
-	}
-	return authMethods
-}
-
-func AuthMethodsRevocationEndpoint(c Configuration) []oidc.AuthMethod {
-	authMethods := []oidc.AuthMethod{
-		oidc.AuthMethodNone,
-		oidc.AuthMethodBasic,
-	}
-	if c.AuthMethodPostSupported() {
-		authMethods = append(authMethods, oidc.AuthMethodPost)
-	}
-	if c.AuthMethodPrivateKeyJWTSupported() {
-		authMethods = append(authMethods, oidc.AuthMethodPrivateKeyJWT)
-	}
-	return authMethods
-}
-
 func CodeChallengeMethods(c Configuration) []oidc.CodeChallengeMethod {
 	codeMethods := make([]oidc.CodeChallengeMethod, 0, 1)
 	if c.CodeMethodS256Supported() {
@ -173,24 +210,3 @@ func CodeChallengeMethods(c Configuration) []oidc.CodeChallengeMethod {
 	}
 	return codeMethods
 }
-
-func IntrospectionSigAlgorithms(c Configuration) []string {
-	if !c.IntrospectionAuthMethodPrivateKeyJWTSupported() {
-		return nil
-	}
-	return c.IntrospectionEndpointSigningAlgorithmsSupported()
-}
-
-func RevocationSigAlgorithms(c Configuration) []string {
-	if !c.RevocationAuthMethodPrivateKeyJWTSupported() {
-		return nil
-	}
-	return c.RevocationEndpointSigningAlgorithmsSupported()
-}
-
-func RequestObjectSigAlgorithms(c Configuration) []string {
-	if !c.RequestObjectSupported() {
-		return nil
-	}
-	return c.RequestObjectSigningAlgorithmsSupported()
-}
--- a/pkg/op/discovery_test.go
+++ b/pkg/op/discovery_test.go
@ -1,12 +1,13 @@
 package op_test

 import (
+	"context"
 	"net/http"
 	"net/http/httptest"
-	"reflect"
 	"testing"

 	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"gopkg.in/square/go-jose.v2"

@ -47,8 +48,9 @@ func TestDiscover(t *testing.T) {

 func TestCreateDiscoveryConfig(t *testing.T) {
 	type args struct {
-		c op.Configuration
-		s op.Signer
+		request *http.Request
+		c       op.Configuration
+		s       op.DiscoverStorage
 	}
 	tests := []struct {
 		name string
@ -59,9 +61,8 @@ func TestCreateDiscoveryConfig(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := op.CreateDiscoveryConfig(tt.args.c, tt.args.s); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("CreateDiscoveryConfig() = %v, want %v", got, tt.want)
-			}
+			got := op.CreateDiscoveryConfig(tt.args.request, tt.args.c, tt.args.s)
+			assert.Equal(t, tt.want, got)
 		})
 	}
 }
@ -83,9 +84,8 @@ func Test_scopes(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := op.Scopes(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("scopes() = %v, want %v", got, tt.want)
-			}
+			got := op.Scopes(tt.args.c)
+			assert.Equal(t, tt.want, got)
 		})
 	}
 }
@ -99,13 +99,16 @@ func Test_ResponseTypes(t *testing.T) {
 		args args
 		want []string
 	}{
-		// TODO: Add test cases.
+		{
+			"code and implicit flow",
+			args{},
+			[]string{"code", "id_token", "id_token token"},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := op.ResponseTypes(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("responseTypes() = %v, want %v", got, tt.want)
-			}
+			got := op.ResponseTypes(tt.args.c)
+			assert.Equal(t, tt.want, got)
 		})
 	}
 }
@ -117,63 +120,48 @@ func Test_GrantTypes(t *testing.T) {
 	tests := []struct {
 		name string
 		args args
-		want []string
-	}{
-		// TODO: Add test cases.
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := op.GrantTypes(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("grantTypes() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestSupportedClaims(t *testing.T) {
-	type args struct {
-		c op.Configuration
-	}
-	tests := []struct {
-		name string
-		args args
-		want []string
-	}{
-		// TODO: Add test cases.
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := op.SupportedClaims(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("SupportedClaims() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func Test_SigAlgorithms(t *testing.T) {
-	m := mock.NewMockSigner(gomock.NewController(t))
-	type args struct {
-		s op.Signer
-	}
-	tests := []struct {
-		name string
-		args args
-		want []string
+		want []oidc.GrantType
 	}{
 		{
-			"",
-			args{func() op.Signer {
-				m.EXPECT().SignatureAlgorithm().Return(jose.RS256)
-				return m
-			}()},
-			[]string{"RS256"},
+			"code and implicit flow",
+			args{
+				func() op.Configuration {
+					c := mock.NewMockConfiguration(gomock.NewController(t))
+					c.EXPECT().GrantTypeRefreshTokenSupported().Return(false)
+					c.EXPECT().GrantTypeTokenExchangeSupported().Return(false)
+					c.EXPECT().GrantTypeJWTAuthorizationSupported().Return(false)
+					return c
+				}(),
+			},
+			[]oidc.GrantType{
+				oidc.GrantTypeCode,
+				oidc.GrantTypeImplicit,
+			},
+		},
+		{
+			"code, implicit flow, refresh token, token exchange, jwt profile",
+			args{
+				func() op.Configuration {
+					c := mock.NewMockConfiguration(gomock.NewController(t))
+					c.EXPECT().GrantTypeRefreshTokenSupported().Return(true)
+					c.EXPECT().GrantTypeTokenExchangeSupported().Return(true)
+					c.EXPECT().GrantTypeJWTAuthorizationSupported().Return(true)
+					return c
+				}(),
+			},
+			[]oidc.GrantType{
+				oidc.GrantTypeCode,
+				oidc.GrantTypeImplicit,
+				oidc.GrantTypeRefreshToken,
+				oidc.GrantTypeTokenExchange,
+				oidc.GrantTypeBearer,
+			},
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := op.SigAlgorithms(tt.args.s); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("sigAlgorithms() = %v, want %v", got, tt.want)
-			}
+			got := op.GrantTypes(tt.args.c)
+			assert.Equal(t, tt.want, got)
 		})
 	}
 }
@ -195,9 +183,80 @@ func Test_SubjectTypes(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := op.SubjectTypes(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("subjectTypes() = %v, want %v", got, tt.want)
-			}
+			got := op.SubjectTypes(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_SigAlgorithms(t *testing.T) {
+	m := mock.NewMockDiscoverStorage(gomock.NewController(t))
+	type args struct {
+		s op.DiscoverStorage
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			"",
+			args{func() op.DiscoverStorage {
+				m.EXPECT().SignatureAlgorithms(gomock.Any()).Return([]jose.SignatureAlgorithm{jose.RS256}, nil)
+				return m
+			}()},
+			[]string{"RS256"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.SigAlgorithms(context.Background(), tt.args.s)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_RequestObjectSigAlgorithms(t *testing.T) {
+	m := mock.NewMockConfiguration(gomock.NewController(t))
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			"not supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().RequestObjectSupported().Return(false)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().RequestObjectSupported().Return(true)
+				m.EXPECT().RequestObjectSigningAlgorithmsSupported().Return(nil)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, list",
+			args{func() op.Configuration {
+				m.EXPECT().RequestObjectSupported().Return(true)
+				m.EXPECT().RequestObjectSigningAlgorithmsSupported().Return([]string{"RS256"})
+				return m
+			}()},
+			[]string{"RS256"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.RequestObjectSigAlgorithms(tt.args.c)
+			assert.Equal(t, tt.want, got)
 		})
 	}
 }
@ -244,9 +303,311 @@ func Test_AuthMethodsTokenEndpoint(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := op.AuthMethodsTokenEndpoint(tt.args.c); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("authMethods() = %v, want %v", got, tt.want)
-			}
+			got := op.AuthMethodsTokenEndpoint(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_TokenSigAlgorithms(t *testing.T) {
+	m := mock.NewMockConfiguration(gomock.NewController(t))
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			"not supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(false)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(true)
+				m.EXPECT().TokenEndpointSigningAlgorithmsSupported().Return(nil)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, list",
+			args{func() op.Configuration {
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(true)
+				m.EXPECT().TokenEndpointSigningAlgorithmsSupported().Return([]string{"RS256"})
+				return m
+			}()},
+			[]string{"RS256"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.TokenSigAlgorithms(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_IntrospectionSigAlgorithms(t *testing.T) {
+	m := mock.NewMockConfiguration(gomock.NewController(t))
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			"not supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().IntrospectionAuthMethodPrivateKeyJWTSupported().Return(false)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().IntrospectionAuthMethodPrivateKeyJWTSupported().Return(true)
+				m.EXPECT().IntrospectionEndpointSigningAlgorithmsSupported().Return(nil)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, list",
+			args{func() op.Configuration {
+				m.EXPECT().IntrospectionAuthMethodPrivateKeyJWTSupported().Return(true)
+				m.EXPECT().IntrospectionEndpointSigningAlgorithmsSupported().Return([]string{"RS256"})
+				return m
+			}()},
+			[]string{"RS256"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.IntrospectionSigAlgorithms(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_AuthMethodsIntrospectionEndpoint(t *testing.T) {
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []oidc.AuthMethod
+	}{
+		{
+			"basic only",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(false)
+				return m
+			}()},
+			[]oidc.AuthMethod{oidc.AuthMethodBasic},
+		},
+		{
+			"basic and private_key_jwt",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(true)
+				return m
+			}()},
+			[]oidc.AuthMethod{oidc.AuthMethodBasic, oidc.AuthMethodPrivateKeyJWT},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.AuthMethodsIntrospectionEndpoint(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_RevocationSigAlgorithms(t *testing.T) {
+	m := mock.NewMockConfiguration(gomock.NewController(t))
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			"not supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().RevocationAuthMethodPrivateKeyJWTSupported().Return(false)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, empty",
+			args{func() op.Configuration {
+				m.EXPECT().RevocationAuthMethodPrivateKeyJWTSupported().Return(true)
+				m.EXPECT().RevocationEndpointSigningAlgorithmsSupported().Return(nil)
+				return m
+			}()},
+			nil,
+		},
+		{
+			"supported, list",
+			args{func() op.Configuration {
+				m.EXPECT().RevocationAuthMethodPrivateKeyJWTSupported().Return(true)
+				m.EXPECT().RevocationEndpointSigningAlgorithmsSupported().Return([]string{"RS256"})
+				return m
+			}()},
+			[]string{"RS256"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.RevocationSigAlgorithms(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_AuthMethodsRevocationEndpoint(t *testing.T) {
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []oidc.AuthMethod
+	}{
+		{
+			"none and basic",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().AuthMethodPostSupported().Return(false)
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(false)
+				return m
+			}()},
+			[]oidc.AuthMethod{oidc.AuthMethodNone, oidc.AuthMethodBasic},
+		},
+		{
+			"none, basic and post",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().AuthMethodPostSupported().Return(true)
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(false)
+				return m
+			}()},
+			[]oidc.AuthMethod{oidc.AuthMethodNone, oidc.AuthMethodBasic, oidc.AuthMethodPost},
+		},
+		{
+			"none, basic, post and private_key_jwt",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().AuthMethodPostSupported().Return(true)
+				m.EXPECT().AuthMethodPrivateKeyJWTSupported().Return(true)
+				return m
+			}()},
+			[]oidc.AuthMethod{oidc.AuthMethodNone, oidc.AuthMethodBasic, oidc.AuthMethodPost, oidc.AuthMethodPrivateKeyJWT},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.AuthMethodsRevocationEndpoint(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func TestSupportedClaims(t *testing.T) {
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			"scopes",
+			args{},
+			[]string{
+				"sub",
+				"aud",
+				"exp",
+				"iat",
+				"iss",
+				"auth_time",
+				"nonce",
+				"acr",
+				"amr",
+				"c_hash",
+				"at_hash",
+				"act",
+				"scopes",
+				"client_id",
+				"azp",
+				"preferred_username",
+				"name",
+				"family_name",
+				"given_name",
+				"locale",
+				"email",
+				"email_verified",
+				"phone_number",
+				"phone_number_verified",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.SupportedClaims(tt.args.c)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_CodeChallengeMethods(t *testing.T) {
+	type args struct {
+		c op.Configuration
+	}
+	tests := []struct {
+		name string
+		args args
+		want []oidc.CodeChallengeMethod
+	}{
+		{
+			"not supported",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().CodeMethodS256Supported().Return(false)
+				return m
+			}()},
+			[]oidc.CodeChallengeMethod{},
+		},
+		{
+			"S256",
+			args{func() op.Configuration {
+				m := mock.NewMockConfiguration(gomock.NewController(t))
+				m.EXPECT().CodeMethodS256Supported().Return(true)
+				return m
+			}()},
+			[]oidc.CodeChallengeMethod{oidc.CodeChallengeMethodS256},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := op.CodeChallengeMethods(tt.args.c)
+			assert.Equal(t, tt.want, got)
 		})
 	}
 }
--- a/pkg/op/keys.go
+++ b/pkg/op/keys.go
@ -10,7 +10,7 @@ import (
 )

 type KeyProvider interface {
-	GetKeySet(context.Context) (*jose.JSONWebKeySet, error)
+	KeySet(context.Context) ([]Key, error)
 }

 func keysHandler(k KeyProvider) func(http.ResponseWriter, *http.Request) {
@ -20,10 +20,23 @@ func keysHandler(k KeyProvider) func(http.ResponseWriter, *http.Request) {
 }

 func Keys(w http.ResponseWriter, r *http.Request, k KeyProvider) {
-	keySet, err := k.GetKeySet(r.Context())
+	keySet, err := k.KeySet(r.Context())
 	if err != nil {
 		httphelper.MarshalJSONWithStatus(w, err, http.StatusInternalServerError)
 		return
 	}
-	httphelper.MarshalJSON(w, keySet)
+	httphelper.MarshalJSON(w, jsonWebKeySet(keySet))
+}
+
+func jsonWebKeySet(keys []Key) *jose.JSONWebKeySet {
+	webKeys := make([]jose.JSONWebKey, len(keys))
+	for i, key := range keys {
+		webKeys[i] = jose.JSONWebKey{
+			KeyID:     key.ID(),
+			Algorithm: string(key.Algorithm()),
+			Use:       key.Use(),
+			Key:       key.Key(),
+		}
+	}
+	return &jose.JSONWebKeySet{Keys: webKeys}
 }
--- a/pkg/op/keys_test.go
+++ b/pkg/op/keys_test.go
@ -35,7 +35,7 @@ func TestKeys(t *testing.T) {
 			args: args{
 				k: func() op.KeyProvider {
 					m := mock.NewMockKeyProvider(gomock.NewController(t))
-					m.EXPECT().GetKeySet(gomock.Any()).Return(nil, oidc.ErrServerError())
+					m.EXPECT().KeySet(gomock.Any()).Return(nil, oidc.ErrServerError())
 					return m
 				}(),
 			},
@ -51,39 +51,39 @@ func TestKeys(t *testing.T) {
 			args: args{
 				k: func() op.KeyProvider {
 					m := mock.NewMockKeyProvider(gomock.NewController(t))
-					m.EXPECT().GetKeySet(gomock.Any()).Return(nil, nil)
+					m.EXPECT().KeySet(gomock.Any()).Return(nil, nil)
 					return m
 				}(),
 			},
 			res: res{
 				statusCode:  http.StatusOK,
 				contentType: "application/json",
+				body: `{"keys":[]}
+`,
 			},
 		},
 		{
 			name: "list",
 			args: args{
 				k: func() op.KeyProvider {
-					m := mock.NewMockKeyProvider(gomock.NewController(t))
-					m.EXPECT().GetKeySet(gomock.Any()).Return(
-						&jose.JSONWebKeySet{Keys: []jose.JSONWebKey{
-							{
-								Key: &rsa.PublicKey{
-									N: big.NewInt(1),
-									E: 1,
-								},
-								KeyID: "id",
-							},
-						}},
-						nil,
-					)
+					ctrl := gomock.NewController(t)
+					m := mock.NewMockKeyProvider(ctrl)
+					k := mock.NewMockKey(ctrl)
+					k.EXPECT().Key().Return(&rsa.PublicKey{
+						N: big.NewInt(1),
+						E: 1,
+					})
+					k.EXPECT().ID().Return("id")
+					k.EXPECT().Algorithm().Return(jose.RS256)
+					k.EXPECT().Use().Return("sig")
+					m.EXPECT().KeySet(gomock.Any()).Return([]op.Key{k}, nil)
 					return m
 				}(),
 			},
 			res: res{
 				statusCode:  http.StatusOK,
 				contentType: "application/json",
-				body: `{"keys":[{"kty":"RSA","kid":"id","n":"AQ","e":"AQ"}]}
+				body: `{"keys":[{"use":"sig","kty":"RSA","kid":"id","alg":"RS256","n":"AQ","e":"AQ"}]}
 `,
 			},
 		},
--- a/pkg/op/mock/authorizer.mock.go
+++ b/pkg/op/mock/authorizer.mock.go
@ -5,6 +5,7 @@
 package mock

 import (
+	context "context"
 	reflect "reflect"

 	http "github.com/caos/oidc/pkg/http"
@ -78,31 +79,17 @@ func (mr *MockAuthorizerMockRecorder) Encoder() *gomock.Call {
 }

 // IDTokenHintVerifier mocks base method.
-func (m *MockAuthorizer) IDTokenHintVerifier() op.IDTokenHintVerifier {
+func (m *MockAuthorizer) IDTokenHintVerifier(arg0 context.Context) op.IDTokenHintVerifier {
 	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "IDTokenHintVerifier")
+	ret := m.ctrl.Call(m, "IDTokenHintVerifier", arg0)
 	ret0, _ := ret[0].(op.IDTokenHintVerifier)
 	return ret0
 }

 // IDTokenHintVerifier indicates an expected call of IDTokenHintVerifier.
-func (mr *MockAuthorizerMockRecorder) IDTokenHintVerifier() *gomock.Call {
+func (mr *MockAuthorizerMockRecorder) IDTokenHintVerifier(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IDTokenHintVerifier", reflect.TypeOf((*MockAuthorizer)(nil).IDTokenHintVerifier))
-}
-
-// Issuer mocks base method.
-func (m *MockAuthorizer) Issuer() string {
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "Issuer")
-	ret0, _ := ret[0].(string)
-	return ret0
-}
-
-// Issuer indicates an expected call of Issuer.
-func (mr *MockAuthorizerMockRecorder) Issuer() *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Issuer", reflect.TypeOf((*MockAuthorizer)(nil).Issuer))
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IDTokenHintVerifier", reflect.TypeOf((*MockAuthorizer)(nil).IDTokenHintVerifier), arg0)
 }

 // RequestObjectSupported mocks base method.
@ -119,20 +106,6 @@ func (mr *MockAuthorizerMockRecorder) RequestObjectSupported() *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "RequestObjectSupported", reflect.TypeOf((*MockAuthorizer)(nil).RequestObjectSupported))
 }

-// Signer mocks base method.
-func (m *MockAuthorizer) Signer() op.Signer {
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "Signer")
-	ret0, _ := ret[0].(op.Signer)
-	return ret0
-}
-
-// Signer indicates an expected call of Signer.
-func (mr *MockAuthorizerMockRecorder) Signer() *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Signer", reflect.TypeOf((*MockAuthorizer)(nil).Signer))
-}
-
 // Storage mocks base method.
 func (m *MockAuthorizer) Storage() op.Storage {
 	m.ctrl.T.Helper()
--- a/pkg/op/mock/authorizer.mock.impl.go
+++ b/pkg/op/mock/authorizer.mock.impl.go
@ -20,7 +20,7 @@ func NewAuthorizerExpectValid(t *testing.T, wantErr bool) op.Authorizer {
 	m := NewAuthorizer(t)
 	ExpectDecoder(m)
 	ExpectEncoder(m)
-	ExpectSigner(m, t)
+	//ExpectSigner(m, t)
 	ExpectStorage(m, t)
 	ExpectVerifier(m, t)
 	// ExpectErrorHandler(m, t, wantErr)
@ -47,17 +47,18 @@ func ExpectEncoder(a op.Authorizer) {
 	mockA.EXPECT().Encoder().AnyTimes().Return(schema.NewEncoder())
 }

-func ExpectSigner(a op.Authorizer, t *testing.T) {
-	mockA := a.(*MockAuthorizer)
-	mockA.EXPECT().Signer().DoAndReturn(
-		func() op.Signer {
-			return &Sig{}
-		})
-}
+//
+//func ExpectSigner(a op.Authorizer, t *testing.T) {
+//	mockA := a.(*MockAuthorizer)
+//	mockA.EXPECT().Signer().DoAndReturn(
+//		func() op.Signer {
+//			return &Sig{}
+//		})
+//}

 func ExpectVerifier(a op.Authorizer, t *testing.T) {
 	mockA := a.(*MockAuthorizer)
-	mockA.EXPECT().IDTokenHintVerifier().DoAndReturn(
+	mockA.EXPECT().IDTokenHintVerifier(gomock.Any()).DoAndReturn(
 		func() op.IDTokenHintVerifier {
 			return op.NewIDTokenHintVerifier("", nil)
 		})
--- a/pkg/op/mock/configuration.mock.go
+++ b/pkg/op/mock/configuration.mock.go
@ -5,6 +5,7 @@
 package mock

 import (
+	http "net/http"
 	reflect "reflect"

 	op "github.com/caos/oidc/pkg/op"
@ -147,6 +148,20 @@ func (mr *MockConfigurationMockRecorder) GrantTypeTokenExchangeSupported() *gomo
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GrantTypeTokenExchangeSupported", reflect.TypeOf((*MockConfiguration)(nil).GrantTypeTokenExchangeSupported))
 }

+// Insecure mocks base method.
+func (m *MockConfiguration) Insecure() bool {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Insecure")
+	ret0, _ := ret[0].(bool)
+	return ret0
+}
+
+// Insecure indicates an expected call of Insecure.
+func (mr *MockConfigurationMockRecorder) Insecure() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Insecure", reflect.TypeOf((*MockConfiguration)(nil).Insecure))
+}
+
 // IntrospectionAuthMethodPrivateKeyJWTSupported mocks base method.
 func (m *MockConfiguration) IntrospectionAuthMethodPrivateKeyJWTSupported() bool {
 	m.ctrl.T.Helper()
@ -189,18 +204,18 @@ func (mr *MockConfigurationMockRecorder) IntrospectionEndpointSigningAlgorithmsS
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IntrospectionEndpointSigningAlgorithmsSupported", reflect.TypeOf((*MockConfiguration)(nil).IntrospectionEndpointSigningAlgorithmsSupported))
 }

-// Issuer mocks base method.
-func (m *MockConfiguration) Issuer() string {
+// IssuerFromRequest mocks base method.
+func (m *MockConfiguration) IssuerFromRequest(arg0 *http.Request) string {
 	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "Issuer")
+	ret := m.ctrl.Call(m, "IssuerFromRequest", arg0)
 	ret0, _ := ret[0].(string)
 	return ret0
 }

-// Issuer indicates an expected call of Issuer.
-func (mr *MockConfigurationMockRecorder) Issuer() *gomock.Call {
+// IssuerFromRequest indicates an expected call of IssuerFromRequest.
+func (mr *MockConfigurationMockRecorder) IssuerFromRequest(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Issuer", reflect.TypeOf((*MockConfiguration)(nil).Issuer))
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IssuerFromRequest", reflect.TypeOf((*MockConfiguration)(nil).IssuerFromRequest), arg0)
 }

 // KeysEndpoint mocks base method.
--- a/pkg/op/mock/generate.go
+++ b/pkg/op/mock/generate.go
@ -4,5 +4,6 @@ package mock
 //go:generate mockgen -package mock -destination ./authorizer.mock.go github.com/caos/oidc/pkg/op Authorizer
 //go:generate mockgen -package mock -destination ./client.mock.go github.com/caos/oidc/pkg/op Client
 //go:generate mockgen -package mock -destination ./configuration.mock.go github.com/caos/oidc/pkg/op Configuration
-//go:generate mockgen -package mock -destination ./signer.mock.go github.com/caos/oidc/pkg/op Signer
+//go:generate mockgen -package mock -destination ./discovery.mock.go github.com/caos/oidc/pkg/op DiscoverStorage
+//go:generate mockgen -package mock -destination ./signer.mock.go github.com/caos/oidc/pkg/op SigningKey,Key
 //go:generate mockgen -package mock -destination ./key.mock.go github.com/caos/oidc/pkg/op KeyProvider
--- a/pkg/op/mock/key.mock.go
+++ b/pkg/op/mock/key.mock.go
@ -8,8 +8,8 @@ import (
 	context "context"
 	reflect "reflect"

+	op "github.com/caos/oidc/pkg/op"
 	gomock "github.com/golang/mock/gomock"
-	jose "gopkg.in/square/go-jose.v2"
 )

 // MockKeyProvider is a mock of KeyProvider interface.
@ -35,17 +35,17 @@ func (m *MockKeyProvider) EXPECT() *MockKeyProviderMockRecorder {
 	return m.recorder
 }

-// GetKeySet mocks base method.
-func (m *MockKeyProvider) GetKeySet(arg0 context.Context) (*jose.JSONWebKeySet, error) {
+// KeySet mocks base method.
+func (m *MockKeyProvider) KeySet(arg0 context.Context) ([]op.Key, error) {
 	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "GetKeySet", arg0)
-	ret0, _ := ret[0].(*jose.JSONWebKeySet)
+	ret := m.ctrl.Call(m, "KeySet", arg0)
+	ret0, _ := ret[0].([]op.Key)
 	ret1, _ := ret[1].(error)
 	return ret0, ret1
 }

-// GetKeySet indicates an expected call of GetKeySet.
-func (mr *MockKeyProviderMockRecorder) GetKeySet(arg0 interface{}) *gomock.Call {
+// KeySet indicates an expected call of KeySet.
+func (mr *MockKeyProviderMockRecorder) KeySet(arg0 interface{}) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetKeySet", reflect.TypeOf((*MockKeyProvider)(nil).GetKeySet), arg0)
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "KeySet", reflect.TypeOf((*MockKeyProvider)(nil).KeySet), arg0)
 }
--- a/pkg/op/mock/signer.mock.go
+++ b/pkg/op/mock/signer.mock.go
@ -1,56 +1,55 @@
 // Code generated by MockGen. DO NOT EDIT.
-// Source: github.com/caos/oidc/pkg/op (interfaces: Signer)
+// Source: github.com/caos/oidc/pkg/op (interfaces: SigningKey,Key)

 // Package mock is a generated GoMock package.
 package mock

 import (
-	context "context"
 	reflect "reflect"

 	gomock "github.com/golang/mock/gomock"
 	jose "gopkg.in/square/go-jose.v2"
 )

-// MockSigner is a mock of Signer interface.
-type MockSigner struct {
+// MockSigningKey is a mock of SigningKey interface.
+type MockSigningKey struct {
 	ctrl     *gomock.Controller
-	recorder *MockSignerMockRecorder
+	recorder *MockSigningKeyMockRecorder
 }

-// MockSignerMockRecorder is the mock recorder for MockSigner.
-type MockSignerMockRecorder struct {
-	mock *MockSigner
+// MockSigningKeyMockRecorder is the mock recorder for MockSigningKey.
+type MockSigningKeyMockRecorder struct {
+	mock *MockSigningKey
 }

-// NewMockSigner creates a new mock instance.
-func NewMockSigner(ctrl *gomock.Controller) *MockSigner {
-	mock := &MockSigner{ctrl: ctrl}
-	mock.recorder = &MockSignerMockRecorder{mock}
+// NewMockSigningKey creates a new mock instance.
+func NewMockSigningKey(ctrl *gomock.Controller) *MockSigningKey {
+	mock := &MockSigningKey{ctrl: ctrl}
+	mock.recorder = &MockSigningKeyMockRecorder{mock}
 	return mock
 }

 // EXPECT returns an object that allows the caller to indicate expected use.
-func (m *MockSigner) EXPECT() *MockSignerMockRecorder {
+func (m *MockSigningKey) EXPECT() *MockSigningKeyMockRecorder {
 	return m.recorder
 }

-// Health mocks base method.
-func (m *MockSigner) Health(arg0 context.Context) error {
+// Key mocks base method.
+func (m *MockSigningKey) Key() interface{} {
 	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "Health", arg0)
-	ret0, _ := ret[0].(error)
+	ret := m.ctrl.Call(m, "Key")
+	ret0, _ := ret[0].(interface{})
 	return ret0
 }

-// Health indicates an expected call of Health.
-func (mr *MockSignerMockRecorder) Health(arg0 interface{}) *gomock.Call {
+// Key indicates an expected call of Key.
+func (mr *MockSigningKeyMockRecorder) Key() *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Health", reflect.TypeOf((*MockSigner)(nil).Health), arg0)
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Key", reflect.TypeOf((*MockSigningKey)(nil).Key))
 }

 // SignatureAlgorithm mocks base method.
-func (m *MockSigner) SignatureAlgorithm() jose.SignatureAlgorithm {
+func (m *MockSigningKey) SignatureAlgorithm() jose.SignatureAlgorithm {
 	m.ctrl.T.Helper()
 	ret := m.ctrl.Call(m, "SignatureAlgorithm")
 	ret0, _ := ret[0].(jose.SignatureAlgorithm)
@ -58,21 +57,86 @@ func (m *MockSigner) SignatureAlgorithm() jose.SignatureAlgorithm {
 }

 // SignatureAlgorithm indicates an expected call of SignatureAlgorithm.
-func (mr *MockSignerMockRecorder) SignatureAlgorithm() *gomock.Call {
+func (mr *MockSigningKeyMockRecorder) SignatureAlgorithm() *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SignatureAlgorithm", reflect.TypeOf((*MockSigner)(nil).SignatureAlgorithm))
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SignatureAlgorithm", reflect.TypeOf((*MockSigningKey)(nil).SignatureAlgorithm))
 }

-// Signer mocks base method.
-func (m *MockSigner) Signer() jose.Signer {
+// MockKey is a mock of Key interface.
+type MockKey struct {
+	ctrl     *gomock.Controller
+	recorder *MockKeyMockRecorder
+}
+
+// MockKeyMockRecorder is the mock recorder for MockKey.
+type MockKeyMockRecorder struct {
+	mock *MockKey
+}
+
+// NewMockKey creates a new mock instance.
+func NewMockKey(ctrl *gomock.Controller) *MockKey {
+	mock := &MockKey{ctrl: ctrl}
+	mock.recorder = &MockKeyMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockKey) EXPECT() *MockKeyMockRecorder {
+	return m.recorder
+}
+
+// Algorithm mocks base method.
+func (m *MockKey) Algorithm() jose.SignatureAlgorithm {
 	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "Signer")
-	ret0, _ := ret[0].(jose.Signer)
+	ret := m.ctrl.Call(m, "Algorithm")
+	ret0, _ := ret[0].(jose.SignatureAlgorithm)
 	return ret0
 }

-// Signer indicates an expected call of Signer.
-func (mr *MockSignerMockRecorder) Signer() *gomock.Call {
+// Algorithm indicates an expected call of Algorithm.
+func (mr *MockKeyMockRecorder) Algorithm() *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Signer", reflect.TypeOf((*MockSigner)(nil).Signer))
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Algorithm", reflect.TypeOf((*MockKey)(nil).Algorithm))
+}
+
+// ID mocks base method.
+func (m *MockKey) ID() string {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ID")
+	ret0, _ := ret[0].(string)
+	return ret0
+}
+
+// ID indicates an expected call of ID.
+func (mr *MockKeyMockRecorder) ID() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ID", reflect.TypeOf((*MockKey)(nil).ID))
+}
+
+// Key mocks base method.
+func (m *MockKey) Key() interface{} {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Key")
+	ret0, _ := ret[0].(interface{})
+	return ret0
+}
+
+// Key indicates an expected call of Key.
+func (mr *MockKeyMockRecorder) Key() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Key", reflect.TypeOf((*MockKey)(nil).Key))
+}
+
+// Use mocks base method.
+func (m *MockKey) Use() string {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Use")
+	ret0, _ := ret[0].(string)
+	return ret0
+}
+
+// Use indicates an expected call of Use.
+func (mr *MockKeyMockRecorder) Use() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Use", reflect.TypeOf((*MockKey)(nil).Use))
 }
--- a/pkg/op/mock/storage.mock.go
+++ b/pkg/op/mock/storage.mock.go
@ -174,21 +174,6 @@ func (mr *MockStorageMockRecorder) GetKeyByIDAndUserID(arg0, arg1, arg2 interfac
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetKeyByIDAndUserID", reflect.TypeOf((*MockStorage)(nil).GetKeyByIDAndUserID), arg0, arg1, arg2)
 }

-// GetKeySet mocks base method.
-func (m *MockStorage) GetKeySet(arg0 context.Context) (*jose.JSONWebKeySet, error) {
-	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "GetKeySet", arg0)
-	ret0, _ := ret[0].(*jose.JSONWebKeySet)
-	ret1, _ := ret[1].(error)
-	return ret0, ret1
-}
-
-// GetKeySet indicates an expected call of GetKeySet.
-func (mr *MockStorageMockRecorder) GetKeySet(arg0 interface{}) *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetKeySet", reflect.TypeOf((*MockStorage)(nil).GetKeySet), arg0)
-}
-
 // GetPrivateClaimsFromScopes mocks base method.
 func (m *MockStorage) GetPrivateClaimsFromScopes(arg0 context.Context, arg1, arg2 string, arg3 []string) (map[string]interface{}, error) {
 	m.ctrl.T.Helper()
@ -204,18 +189,6 @@ func (mr *MockStorageMockRecorder) GetPrivateClaimsFromScopes(arg0, arg1, arg2,
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetPrivateClaimsFromScopes", reflect.TypeOf((*MockStorage)(nil).GetPrivateClaimsFromScopes), arg0, arg1, arg2, arg3)
 }

-// GetSigningKey mocks base method.
-func (m *MockStorage) GetSigningKey(arg0 context.Context, arg1 chan<- jose.SigningKey) {
-	m.ctrl.T.Helper()
-	m.ctrl.Call(m, "GetSigningKey", arg0, arg1)
-}
-
-// GetSigningKey indicates an expected call of GetSigningKey.
-func (mr *MockStorageMockRecorder) GetSigningKey(arg0, arg1 interface{}) *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetSigningKey", reflect.TypeOf((*MockStorage)(nil).GetSigningKey), arg0, arg1)
-}
-
 // Health mocks base method.
 func (m *MockStorage) Health(arg0 context.Context) error {
 	m.ctrl.T.Helper()
@ -230,6 +203,21 @@ func (mr *MockStorageMockRecorder) Health(arg0 interface{}) *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Health", reflect.TypeOf((*MockStorage)(nil).Health), arg0)
 }

+// KeySet mocks base method.
+func (m *MockStorage) KeySet(arg0 context.Context) ([]op.Key, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "KeySet", arg0)
+	ret0, _ := ret[0].([]op.Key)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// KeySet indicates an expected call of KeySet.
+func (mr *MockStorageMockRecorder) KeySet(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "KeySet", reflect.TypeOf((*MockStorage)(nil).KeySet), arg0)
+}
+
 // RevokeToken mocks base method.
 func (m *MockStorage) RevokeToken(arg0 context.Context, arg1, arg2, arg3 string) *oidc.Error {
 	m.ctrl.T.Helper()
@ -300,6 +288,36 @@ func (mr *MockStorageMockRecorder) SetUserinfoFromToken(arg0, arg1, arg2, arg3,
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SetUserinfoFromToken", reflect.TypeOf((*MockStorage)(nil).SetUserinfoFromToken), arg0, arg1, arg2, arg3, arg4)
 }

+// SignatureAlgorithms mocks base method.
+func (m *MockStorage) SignatureAlgorithms(arg0 context.Context) ([]jose.SignatureAlgorithm, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "SignatureAlgorithms", arg0)
+	ret0, _ := ret[0].([]jose.SignatureAlgorithm)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// SignatureAlgorithms indicates an expected call of SignatureAlgorithms.
+func (mr *MockStorageMockRecorder) SignatureAlgorithms(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SignatureAlgorithms", reflect.TypeOf((*MockStorage)(nil).SignatureAlgorithms), arg0)
+}
+
+// SigningKey mocks base method.
+func (m *MockStorage) SigningKey(arg0 context.Context) (op.SigningKey, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "SigningKey", arg0)
+	ret0, _ := ret[0].(op.SigningKey)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// SigningKey indicates an expected call of SigningKey.
+func (mr *MockStorageMockRecorder) SigningKey(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SigningKey", reflect.TypeOf((*MockStorage)(nil).SigningKey), arg0)
+}
+
 // TerminateSession mocks base method.
 func (m *MockStorage) TerminateSession(arg0 context.Context, arg1, arg2 string) error {
 	m.ctrl.T.Helper()
--- a/pkg/op/mock/storage.mock.impl.go
+++ b/pkg/op/mock/storage.mock.impl.go
@ -3,11 +3,10 @@ package mock
 import (
 	"context"
 	"errors"
-	"github.com/caos/oidc/pkg/oidc"
 	"testing"
 	"time"

-	"gopkg.in/square/go-jose.v2"
+	"github.com/caos/oidc/pkg/oidc"

 	"github.com/golang/mock/gomock"

@ -40,12 +39,12 @@ func NewMockStorageAny(t *testing.T) op.Storage {

 func NewMockStorageSigningKeyInvalid(t *testing.T) op.Storage {
 	m := NewStorage(t)
-	ExpectSigningKeyInvalid(m)
+	//ExpectSigningKeyInvalid(m)
 	return m
 }
 func NewMockStorageSigningKey(t *testing.T) op.Storage {
 	m := NewStorage(t)
-	ExpectSigningKey(m)
+	//ExpectSigningKey(m)
 	return m
 }

@ -83,23 +82,24 @@ func ExpectValidClientID(s op.Storage) {
 		})
 }

-func ExpectSigningKeyInvalid(s op.Storage) {
-	mockS := s.(*MockStorage)
-	mockS.EXPECT().GetSigningKey(gomock.Any(), gomock.Any()).DoAndReturn(
-		func(_ context.Context, keyCh chan<- jose.SigningKey) {
-			keyCh <- jose.SigningKey{}
-		},
-	)
-}
-
-func ExpectSigningKey(s op.Storage) {
-	mockS := s.(*MockStorage)
-	mockS.EXPECT().GetSigningKey(gomock.Any(), gomock.Any()).DoAndReturn(
-		func(_ context.Context, keyCh chan<- jose.SigningKey) {
-			keyCh <- jose.SigningKey{Algorithm: jose.HS256, Key: []byte("key")}
-		},
-	)
-}
+//
+//func ExpectSigningKeyInvalid(s op.Storage) {
+//	mockS := s.(*MockStorage)
+//	mockS.EXPECT().GetSigningKey(gomock.Any(), gomock.Any()).DoAndReturn(
+//		func(_ context.Context, keyCh chan<- jose.SigningKey) {
+//			keyCh <- jose.SigningKey{}
+//		},
+//	)
+//}
+//
+//func ExpectSigningKey(s op.Storage) {
+//	mockS := s.(*MockStorage)
+//	mockS.EXPECT().GetSigningKey(gomock.Any(), gomock.Any()).DoAndReturn(
+//		func(_ context.Context, keyCh chan<- jose.SigningKey) {
+//			keyCh <- jose.SigningKey{Algorithm: jose.HS256, Key: []byte("key")}
+//		},
+//	)
+//}

 type ConfClient struct {
 	id              string
--- a/pkg/op/op.go
+++ b/pkg/op/op.go
@ -46,11 +46,10 @@ type OpenIDProvider interface {
 	Storage() Storage
 	Decoder() httphelper.Decoder
 	Encoder() httphelper.Encoder
-	IDTokenHintVerifier() IDTokenHintVerifier
-	AccessTokenVerifier() AccessTokenVerifier
+	IDTokenHintVerifier(context.Context) IDTokenHintVerifier
+	AccessTokenVerifier(context.Context) AccessTokenVerifier
 	Crypto() Crypto
 	DefaultLogoutRedirectURI() string
-	Signer() Signer
 	Probes() []ProbesFn
 	HttpHandler() http.Handler
 }
@ -62,31 +61,26 @@ var allowAllOrigins = func(_ string) bool {
 }

 func CreateRouter(o OpenIDProvider, interceptors ...HttpInterceptor) *mux.Router {
-	intercept := buildInterceptor(interceptors...)
 	router := mux.NewRouter()
-	router.Use(handlers.CORS(
-		handlers.AllowCredentials(),
-		handlers.AllowedHeaders([]string{"authorization", "content-type"}),
-		handlers.AllowedOriginValidator(allowAllOrigins),
-	))
+	router.Use(intercept(o.IssuerFromRequest, interceptors...))
 	router.HandleFunc(healthEndpoint, healthHandler)
 	router.HandleFunc(readinessEndpoint, readyHandler(o.Probes()))
-	router.HandleFunc(oidc.DiscoveryEndpoint, discoveryHandler(o, o.Signer()))
-	router.Handle(o.AuthorizationEndpoint().Relative(), intercept(authorizeHandler(o)))
-	router.NewRoute().Path(authCallbackPath(o)).Queries("id", "{id}").Handler(intercept(authorizeCallbackHandler(o)))
-	router.Handle(o.TokenEndpoint().Relative(), intercept(tokenHandler(o)))
+	router.HandleFunc(oidc.DiscoveryEndpoint, discoveryHandler(o, o.Storage()))
+	router.HandleFunc(o.AuthorizationEndpoint().Relative(), authorizeHandler(o))
+	router.NewRoute().Path(authCallbackPath(o)).Queries("id", "{id}").HandlerFunc(authorizeCallbackHandler(o))
+	router.HandleFunc(o.TokenEndpoint().Relative(), tokenHandler(o))
 	router.HandleFunc(o.IntrospectionEndpoint().Relative(), introspectionHandler(o))
 	router.HandleFunc(o.UserinfoEndpoint().Relative(), userinfoHandler(o))
 	router.HandleFunc(o.RevocationEndpoint().Relative(), revocationHandler(o))
-	router.Handle(o.EndSessionEndpoint().Relative(), intercept(endSessionHandler(o)))
+	router.HandleFunc(o.EndSessionEndpoint().Relative(), endSessionHandler(o))
 	router.HandleFunc(o.KeysEndpoint().Relative(), keysHandler(o.Storage()))
 	return router
 }

 //AuthCallbackURL builds the url for the redirect (with the requestID) after a successful login
-func AuthCallbackURL(o OpenIDProvider) func(string) string {
-	return func(requestID string) string {
-		return o.AuthorizationEndpoint().Absolute(o.Issuer()) + authCallbackPathSuffix + "?id=" + requestID
+func AuthCallbackURL(o OpenIDProvider) func(context.Context, string) string {
+	return func(ctx context.Context, requestID string) string {
+		return o.AuthorizationEndpoint().Absolute(IssuerFromContext(ctx)) + authCallbackPathSuffix + "?id=" + requestID
 	}
 }

@ -95,7 +89,6 @@ func authCallbackPath(o OpenIDProvider) string {
 }

 type Config struct {
-	Issuer                   string
 	CryptoKey                [32]byte
 	DefaultLogoutRedirectURI string
 	CodeMethodS256           bool
@ -117,13 +110,16 @@ type endpoints struct {
 	JwksURI            Endpoint
 }

-func NewOpenIDProvider(ctx context.Context, config *Config, storage Storage, opOpts ...Option) (OpenIDProvider, error) {
-	err := ValidateIssuer(config.Issuer)
-	if err != nil {
-		return nil, err
-	}
+func NewOpenIDProvider(ctx context.Context, issuer string, config *Config, storage Storage, opOpts ...Option) (*Provider, error) {
+	return newProvider(ctx, config, storage, StaticIssuer(issuer), opOpts...)
+}

-	o := &openidProvider{
+func NewDynamicOpenIDProvider(ctx context.Context, path string, config *Config, storage Storage, opOpts ...Option) (*Provider, error) {
+	return newProvider(ctx, config, storage, IssuerFromHost(path), opOpts...)
+}
+
+func newProvider(ctx context.Context, config *Config, storage Storage, issuer func(bool) (IssuerFromRequest, error), opOpts ...Option) (_ *Provider, err error) {
+	o := &Provider{
 		config:    config,
 		storage:   storage,
 		endpoints: DefaultEndpoints,
@ -136,9 +132,10 @@ func NewOpenIDProvider(ctx context.Context, config *Config, storage Storage, opO
 		}
 	}

-	keyCh := make(chan jose.SigningKey)
-	go storage.GetSigningKey(ctx, keyCh)
-	o.signer = NewSigner(ctx, storage, keyCh)
+	o.issuer, err = issuer(o.insecure)
+	if err != nil {
+		return nil, err
+	}

 	o.httpHandler = CreateRouter(o, o.interceptors...)

@ -152,171 +149,159 @@ func NewOpenIDProvider(ctx context.Context, config *Config, storage Storage, opO
 	return o, nil
 }

-type openidProvider struct {
-	config              *Config
-	endpoints           *endpoints
-	storage             Storage
-	signer              Signer
-	idTokenHintVerifier IDTokenHintVerifier
-	jwtProfileVerifier  JWTProfileVerifier
-	accessTokenVerifier AccessTokenVerifier
-	keySet              *openIDKeySet
-	crypto              Crypto
-	httpHandler         http.Handler
-	decoder             *schema.Decoder
-	encoder             *schema.Encoder
-	interceptors        []HttpInterceptor
-	timer               <-chan time.Time
+type Provider struct {
+	config       *Config
+	issuer       IssuerFromRequest
+	insecure     bool
+	endpoints    *endpoints
+	storage      Storage
+	keySet       *openIDKeySet
+	crypto       Crypto
+	httpHandler  http.Handler
+	decoder      *schema.Decoder
+	encoder      *schema.Encoder
+	interceptors []HttpInterceptor
+	timer        <-chan time.Time
 }

-func (o *openidProvider) Issuer() string {
-	return o.config.Issuer
+func (o *Provider) IssuerFromRequest(r *http.Request) string {
+	return o.issuer(r)
 }

-func (o *openidProvider) AuthorizationEndpoint() Endpoint {
+func (o *Provider) Insecure() bool {
+	return o.insecure
+}
+
+func (o *Provider) AuthorizationEndpoint() Endpoint {
 	return o.endpoints.Authorization
 }

-func (o *openidProvider) TokenEndpoint() Endpoint {
+func (o *Provider) TokenEndpoint() Endpoint {
 	return o.endpoints.Token
 }

-func (o *openidProvider) IntrospectionEndpoint() Endpoint {
+func (o *Provider) IntrospectionEndpoint() Endpoint {
 	return o.endpoints.Introspection
 }

-func (o *openidProvider) UserinfoEndpoint() Endpoint {
+func (o *Provider) UserinfoEndpoint() Endpoint {
 	return o.endpoints.Userinfo
 }

-func (o *openidProvider) RevocationEndpoint() Endpoint {
+func (o *Provider) RevocationEndpoint() Endpoint {
 	return o.endpoints.Revocation
 }

-func (o *openidProvider) EndSessionEndpoint() Endpoint {
+func (o *Provider) EndSessionEndpoint() Endpoint {
 	return o.endpoints.EndSession
 }

-func (o *openidProvider) KeysEndpoint() Endpoint {
+func (o *Provider) KeysEndpoint() Endpoint {
 	return o.endpoints.JwksURI
 }

-func (o *openidProvider) AuthMethodPostSupported() bool {
+func (o *Provider) AuthMethodPostSupported() bool {
 	return o.config.AuthMethodPost
 }

-func (o *openidProvider) CodeMethodS256Supported() bool {
+func (o *Provider) CodeMethodS256Supported() bool {
 	return o.config.CodeMethodS256
 }

-func (o *openidProvider) AuthMethodPrivateKeyJWTSupported() bool {
+func (o *Provider) AuthMethodPrivateKeyJWTSupported() bool {
 	return o.config.AuthMethodPrivateKeyJWT
 }

-func (o *openidProvider) TokenEndpointSigningAlgorithmsSupported() []string {
+func (o *Provider) TokenEndpointSigningAlgorithmsSupported() []string {
 	return []string{"RS256"}
 }

-func (o *openidProvider) GrantTypeRefreshTokenSupported() bool {
+func (o *Provider) GrantTypeRefreshTokenSupported() bool {
 	return o.config.GrantTypeRefreshToken
 }

-func (o *openidProvider) GrantTypeTokenExchangeSupported() bool {
+func (o *Provider) GrantTypeTokenExchangeSupported() bool {
 	return false
 }

-func (o *openidProvider) GrantTypeJWTAuthorizationSupported() bool {
+func (o *Provider) GrantTypeJWTAuthorizationSupported() bool {
 	return true
 }

-func (o *openidProvider) IntrospectionAuthMethodPrivateKeyJWTSupported() bool {
+func (o *Provider) IntrospectionAuthMethodPrivateKeyJWTSupported() bool {
 	return true
 }

-func (o *openidProvider) IntrospectionEndpointSigningAlgorithmsSupported() []string {
+func (o *Provider) IntrospectionEndpointSigningAlgorithmsSupported() []string {
 	return []string{"RS256"}
 }

-func (o *openidProvider) RevocationAuthMethodPrivateKeyJWTSupported() bool {
+func (o *Provider) RevocationAuthMethodPrivateKeyJWTSupported() bool {
 	return true
 }

-func (o *openidProvider) RevocationEndpointSigningAlgorithmsSupported() []string {
+func (o *Provider) RevocationEndpointSigningAlgorithmsSupported() []string {
 	return []string{"RS256"}
 }

-func (o *openidProvider) RequestObjectSupported() bool {
+func (o *Provider) RequestObjectSupported() bool {
 	return o.config.RequestObjectSupported
 }

-func (o *openidProvider) RequestObjectSigningAlgorithmsSupported() []string {
+func (o *Provider) RequestObjectSigningAlgorithmsSupported() []string {
 	return []string{"RS256"}
 }

-func (o *openidProvider) SupportedUILocales() []language.Tag {
+func (o *Provider) SupportedUILocales() []language.Tag {
 	return o.config.SupportedUILocales
 }

-func (o *openidProvider) Storage() Storage {
+func (o *Provider) Storage() Storage {
 	return o.storage
 }

-func (o *openidProvider) Decoder() httphelper.Decoder {
+func (o *Provider) Decoder() httphelper.Decoder {
 	return o.decoder
 }

-func (o *openidProvider) Encoder() httphelper.Encoder {
+func (o *Provider) Encoder() httphelper.Encoder {
 	return o.encoder
 }

-func (o *openidProvider) IDTokenHintVerifier() IDTokenHintVerifier {
-	if o.idTokenHintVerifier == nil {
-		o.idTokenHintVerifier = NewIDTokenHintVerifier(o.Issuer(), o.openIDKeySet())
-	}
-	return o.idTokenHintVerifier
+func (o *Provider) IDTokenHintVerifier(ctx context.Context) IDTokenHintVerifier {
+	return NewIDTokenHintVerifier(IssuerFromContext(ctx), o.openIDKeySet())
 }

-func (o *openidProvider) JWTProfileVerifier() JWTProfileVerifier {
-	if o.jwtProfileVerifier == nil {
-		o.jwtProfileVerifier = NewJWTProfileVerifier(o.Storage(), o.Issuer(), 1*time.Hour, time.Second)
-	}
-	return o.jwtProfileVerifier
+func (o *Provider) JWTProfileVerifier(ctx context.Context) JWTProfileVerifier {
+	return NewJWTProfileVerifier(o.Storage(), IssuerFromContext(ctx), 1*time.Hour, time.Second)
 }

-func (o *openidProvider) AccessTokenVerifier() AccessTokenVerifier {
-	if o.accessTokenVerifier == nil {
-		o.accessTokenVerifier = NewAccessTokenVerifier(o.Issuer(), o.openIDKeySet())
-	}
-	return o.accessTokenVerifier
+func (o *Provider) AccessTokenVerifier(ctx context.Context) AccessTokenVerifier {
+	return NewAccessTokenVerifier(IssuerFromContext(ctx), o.openIDKeySet())
 }

-func (o *openidProvider) openIDKeySet() oidc.KeySet {
+func (o *Provider) openIDKeySet() oidc.KeySet {
 	if o.keySet == nil {
 		o.keySet = &openIDKeySet{o.Storage()}
 	}
 	return o.keySet
 }

-func (o *openidProvider) Crypto() Crypto {
+func (o *Provider) Crypto() Crypto {
 	return o.crypto
 }

-func (o *openidProvider) DefaultLogoutRedirectURI() string {
+func (o *Provider) DefaultLogoutRedirectURI() string {
 	return o.config.DefaultLogoutRedirectURI
 }

-func (o *openidProvider) Signer() Signer {
-	return o.signer
-}
-
-func (o *openidProvider) Probes() []ProbesFn {
+func (o *Provider) Probes() []ProbesFn {
 	return []ProbesFn{
-		ReadySigner(o.Signer()),
 		ReadyStorage(o.Storage()),
 	}
 }

-func (o *openidProvider) HttpHandler() http.Handler {
+func (o *Provider) HttpHandler() http.Handler {
 	return o.httpHandler
 }

@ -327,22 +312,31 @@ type openIDKeySet struct {
 //VerifySignature implements the oidc.KeySet interface
 //providing an implementation for the keys stored in the OP Storage interface
 func (o *openIDKeySet) VerifySignature(ctx context.Context, jws *jose.JSONWebSignature) ([]byte, error) {
-	keySet, err := o.Storage.GetKeySet(ctx)
+	keySet, err := o.Storage.KeySet(ctx)
 	if err != nil {
 		return nil, fmt.Errorf("error fetching keys: %w", err)
 	}
 	keyID, alg := oidc.GetKeyIDAndAlg(jws)
-	key, err := oidc.FindMatchingKey(keyID, oidc.KeyUseSignature, alg, keySet.Keys...)
+	key, err := oidc.FindMatchingKey(keyID, oidc.KeyUseSignature, alg, jsonWebKeySet(keySet).Keys...)
 	if err != nil {
 		return nil, fmt.Errorf("invalid signature: %w", err)
 	}
 	return jws.Verify(&key)
 }

-type Option func(o *openidProvider) error
+type Option func(o *Provider) error
+
+//WithAllowInsecure allows the use of http (instead of https) for issuers
+//this is not recommended for production use and violates the OIDC specification
+func WithAllowInsecure() Option {
+	return func(o *Provider) error {
+		o.insecure = true
+		return nil
+	}
+}

 func WithCustomAuthEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -352,7 +346,7 @@ func WithCustomAuthEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomTokenEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -362,7 +356,7 @@ func WithCustomTokenEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomIntrospectionEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -372,7 +366,7 @@ func WithCustomIntrospectionEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomUserinfoEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -382,7 +376,7 @@ func WithCustomUserinfoEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomRevocationEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -392,7 +386,7 @@ func WithCustomRevocationEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomEndSessionEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -402,7 +396,7 @@ func WithCustomEndSessionEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomKeysEndpoint(endpoint Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		if err := endpoint.Validate(); err != nil {
 			return err
 		}
@ -412,7 +406,7 @@ func WithCustomKeysEndpoint(endpoint Endpoint) Option {
 }

 func WithCustomEndpoints(auth, token, userInfo, revocation, endSession, keys Endpoint) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		o.endpoints.Authorization = auth
 		o.endpoints.Token = token
 		o.endpoints.Userinfo = userInfo
@ -424,24 +418,23 @@ func WithCustomEndpoints(auth, token, userInfo, revocation, endSession, keys End
 }

 func WithHttpInterceptors(interceptors ...HttpInterceptor) Option {
-	return func(o *openidProvider) error {
+	return func(o *Provider) error {
 		o.interceptors = append(o.interceptors, interceptors...)
 		return nil
 	}
 }

-func buildInterceptor(interceptors ...HttpInterceptor) func(http.HandlerFunc) http.Handler {
-	return func(handlerFunc http.HandlerFunc) http.Handler {
-		handler := handlerFuncToHandler(handlerFunc)
+func intercept(i IssuerFromRequest, interceptors ...HttpInterceptor) func(handler http.Handler) http.Handler {
+	cors := handlers.CORS(
+		handlers.AllowCredentials(),
+		handlers.AllowedHeaders([]string{"authorization", "content-type"}),
+		handlers.AllowedOriginValidator(allowAllOrigins),
+	)
+	issuerInterceptor := NewIssuerInterceptor(i)
+	return func(handler http.Handler) http.Handler {
 		for i := len(interceptors) - 1; i >= 0; i-- {
 			handler = interceptors[i](handler)
 		}
-		return handler
+		return cors(issuerInterceptor.Handler(handler))
 	}
 }
-
-func handlerFuncToHandler(handlerFunc http.HandlerFunc) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		handlerFunc(w, r)
-	})
-}
--- a/pkg/op/probes.go
+++ b/pkg/op/probes.go
@ -31,14 +31,6 @@ func Readiness(w http.ResponseWriter, r *http.Request, probes ...ProbesFn) {
 	ok(w)
 }

-func ReadySigner(s Signer) ProbesFn {
-	return func(ctx context.Context) error {
-		if s == nil {
-			return errors.New("no signer")
-		}
-		return s.Health(ctx)
-	}
-}
 func ReadyStorage(s Storage) ProbesFn {
 	return func(ctx context.Context) error {
 		if s == nil {
--- a/pkg/op/session.go
+++ b/pkg/op/session.go
@ -11,7 +11,7 @@ import (
 type SessionEnder interface {
 	Decoder() httphelper.Decoder
 	Storage() Storage
-	IDTokenHintVerifier() IDTokenHintVerifier
+	IDTokenHintVerifier(context.Context) IDTokenHintVerifier
 	DefaultLogoutRedirectURI() string
 }

@ -62,7 +62,7 @@ func ValidateEndSessionRequest(ctx context.Context, req *oidc.EndSessionRequest,
 	if req.IdTokenHint == "" {
 		return session, nil
 	}
-	claims, err := VerifyIDTokenHint(ctx, req.IdTokenHint, ender.IDTokenHintVerifier())
+	claims, err := VerifyIDTokenHint(ctx, req.IdTokenHint, ender.IDTokenHintVerifier(ctx))
 	if err != nil {
 		return nil, oidc.ErrInvalidRequest().WithDescription("id_token_hint invalid").WithParent(err)
 	}
--- a/pkg/op/signer.go
+++ b/pkg/op/signer.go
@ -1,82 +1,38 @@
 package op

 import (
-	"context"
 	"errors"

-	"github.com/caos/logging"
 	"gopkg.in/square/go-jose.v2"
 )

-type Signer interface {
-	Health(ctx context.Context) error
-	Signer() jose.Signer
+var (
+	ErrSignerCreationFailed = errors.New("signer creation failed")
+)
+
+type SigningKey interface {
 	SignatureAlgorithm() jose.SignatureAlgorithm
+	Key() interface{}
+	ID() string
 }

-type tokenSigner struct {
-	signer  jose.Signer
-	storage AuthStorage
-	alg     jose.SignatureAlgorithm
-}
-
-func NewSigner(ctx context.Context, storage AuthStorage, keyCh <-chan jose.SigningKey) Signer {
-	s := &tokenSigner{
-		storage: storage,
-	}
-
-	select {
-	case <-ctx.Done():
-		return nil
-	case key := <-keyCh:
-		s.exchangeSigningKey(key)
-	}
-	go s.refreshSigningKey(ctx, keyCh)
-
-	return s
-}
-
-func (s *tokenSigner) Health(_ context.Context) error {
-	if s.signer == nil {
-		return errors.New("no signer")
-	}
-	if string(s.alg) == "" {
-		return errors.New("no signing algorithm")
-	}
-	return nil
-}
-
-func (s *tokenSigner) Signer() jose.Signer {
-	return s.signer
-}
-
-func (s *tokenSigner) refreshSigningKey(ctx context.Context, keyCh <-chan jose.SigningKey) {
-	for {
-		select {
-		case <-ctx.Done():
-			return
-		case key := <-keyCh:
-			s.exchangeSigningKey(key)
-		}
-	}
-}
-
-func (s *tokenSigner) exchangeSigningKey(key jose.SigningKey) {
-	s.alg = key.Algorithm
-	if key.Algorithm == "" || key.Key == nil {
-		s.signer = nil
-		logging.Warn("signer has no key")
-		return
-	}
-	var err error
-	s.signer, err = jose.NewSigner(key, &jose.SignerOptions{})
+func SignerFromKey(key SigningKey) (jose.Signer, error) {
+	signer, err := jose.NewSigner(jose.SigningKey{
+		Algorithm: key.SignatureAlgorithm(),
+		Key: &jose.JSONWebKey{
+			Key:   key.Key(),
+			KeyID: key.ID(),
+		},
+	}, &jose.SignerOptions{})
 	if err != nil {
-		logging.New().WithError(err).Error("error creating signer")
-		return
+		return nil, ErrSignerCreationFailed //TODO: log / wrap error?
 	}
-	logging.Info("signer exchanged signing key")
+	return signer, nil
 }

-func (s *tokenSigner) SignatureAlgorithm() jose.SignatureAlgorithm {
-	return s.alg
+type Key interface {
+	ID() string
+	Algorithm() jose.SignatureAlgorithm
+	Use() string
+	Key() interface{}
 }
--- a/pkg/op/storage.go
+++ b/pkg/op/storage.go
@ -23,8 +23,9 @@ type AuthStorage interface {
 	TerminateSession(ctx context.Context, userID string, clientID string) error
 	RevokeToken(ctx context.Context, token string, userID string, clientID string) *oidc.Error

-	GetSigningKey(context.Context, chan<- jose.SigningKey)
-	GetKeySet(context.Context) (*jose.JSONWebKeySet, error)
+	SigningKey(context.Context) (SigningKey, error)
+	SignatureAlgorithms(context.Context) ([]jose.SignatureAlgorithm, error)
+	KeySet(context.Context) ([]Key, error)
 }

 type OPStorage interface {
--- a/pkg/op/token.go
+++ b/pkg/op/token.go
@ -10,8 +10,6 @@ import (
 )

 type TokenCreator interface {
-	Issuer() string
-	Signer() Signer
 	Storage() Storage
 	Crypto() Crypto
 }
@ -32,7 +30,7 @@ func CreateTokenResponse(ctx context.Context, request IDTokenRequest, client Cli
 			return nil, err
 		}
 	}
-	idToken, err := CreateIDToken(ctx, creator.Issuer(), request, client.IDTokenLifetime(), accessToken, code, creator.Storage(), creator.Signer(), client)
+	idToken, err := CreateIDToken(ctx, IssuerFromContext(ctx), request, client.IDTokenLifetime(), accessToken, code, creator.Storage(), client)
 	if err != nil {
 		return nil, err
 	}
@ -84,7 +82,7 @@ func CreateAccessToken(ctx context.Context, tokenRequest TokenRequest, accessTok
 	}
 	validity = exp.Add(clockSkew).Sub(time.Now().UTC())
 	if accessTokenType == AccessTokenTypeJWT {
-		accessToken, err = CreateJWT(ctx, creator.Issuer(), tokenRequest, exp, id, creator.Signer(), client, creator.Storage())
+		accessToken, err = CreateJWT(ctx, IssuerFromContext(ctx), tokenRequest, exp, id, client, creator.Storage())
 		return
 	}
 	accessToken, err = CreateBearerToken(id, tokenRequest.GetSubject(), creator.Crypto())
@ -95,7 +93,7 @@ func CreateBearerToken(tokenID, subject string, crypto Crypto) (string, error) {
 	return crypto.Encrypt(tokenID + ":" + subject)
 }

-func CreateJWT(ctx context.Context, issuer string, tokenRequest TokenRequest, exp time.Time, id string, signer Signer, client Client, storage Storage) (string, error) {
+func CreateJWT(ctx context.Context, issuer string, tokenRequest TokenRequest, exp time.Time, id string, client Client, storage Storage) (string, error) {
 	claims := oidc.NewAccessTokenClaims(issuer, tokenRequest.GetSubject(), tokenRequest.GetAudience(), exp, id, client.GetID(), client.ClockSkew())
 	if client != nil {
 		restrictedScopes := client.RestrictAdditionalAccessTokenScopes()(tokenRequest.GetScopes())
@ -105,7 +103,15 @@ func CreateJWT(ctx context.Context, issuer string, tokenRequest TokenRequest, ex
 		}
 		claims.SetPrivateClaims(privateClaims)
 	}
-	return crypto.Sign(claims, signer.Signer())
+	signingKey, err := storage.SigningKey(ctx)
+	if err != nil {
+		return "", err
+	}
+	signer, err := SignerFromKey(signingKey)
+	if err != nil {
+		return "", err
+	}
+	return crypto.Sign(claims, signer)
 }

 type IDTokenRequest interface {
@ -117,7 +123,7 @@ type IDTokenRequest interface {
 	GetSubject() string
 }

-func CreateIDToken(ctx context.Context, issuer string, request IDTokenRequest, validity time.Duration, accessToken, code string, storage Storage, signer Signer, client Client) (string, error) {
+func CreateIDToken(ctx context.Context, issuer string, request IDTokenRequest, validity time.Duration, accessToken, code string, storage Storage, client Client) (string, error) {
 	exp := time.Now().UTC().Add(client.ClockSkew()).Add(validity)
 	var acr, nonce string
 	if authRequest, ok := request.(AuthRequest); ok {
@ -126,8 +132,12 @@ func CreateIDToken(ctx context.Context, issuer string, request IDTokenRequest, v
 	}
 	claims := oidc.NewIDTokenClaims(issuer, request.GetSubject(), request.GetAudience(), exp, request.GetAuthTime(), nonce, acr, request.GetAMR(), request.GetClientID(), client.ClockSkew())
 	scopes := client.RestrictAdditionalIdTokenScopes()(request.GetScopes())
+	signingKey, err := storage.SigningKey(ctx)
+	if err != nil {
+		return "", err
+	}
 	if accessToken != "" {
-		atHash, err := oidc.ClaimHash(accessToken, signer.SignatureAlgorithm())
+		atHash, err := oidc.ClaimHash(accessToken, signingKey.SignatureAlgorithm())
 		if err != nil {
 			return "", err
 		}
@ -145,14 +155,17 @@ func CreateIDToken(ctx context.Context, issuer string, request IDTokenRequest, v
 		claims.SetUserinfo(userInfo)
 	}
 	if code != "" {
-		codeHash, err := oidc.ClaimHash(code, signer.SignatureAlgorithm())
+		codeHash, err := oidc.ClaimHash(code, signingKey.SignatureAlgorithm())
 		if err != nil {
 			return "", err
 		}
 		claims.SetCodeHash(codeHash)
 	}
-
-	return crypto.Sign(claims, signer.Signer())
+	signer, err := SignerFromKey(signingKey)
+	if err != nil {
+		return "", err
+	}
+	return crypto.Sign(claims, signer)
 }

 func removeUserinfoScopes(scopes []string) []string {
--- a/pkg/op/token_intospection.go
+++ b/pkg/op/token_intospection.go
@ -1,6 +1,7 @@
 package op

 import (
+	"context"
 	"errors"
 	"net/http"
 	"net/url"
@ -13,12 +14,12 @@ type Introspector interface {
 	Decoder() httphelper.Decoder
 	Crypto() Crypto
 	Storage() Storage
-	AccessTokenVerifier() AccessTokenVerifier
+	AccessTokenVerifier(context.Context) AccessTokenVerifier
 }

 type IntrospectorJWTProfile interface {
 	Introspector
-	JWTProfileVerifier() JWTProfileVerifier
+	JWTProfileVerifier(context.Context) JWTProfileVerifier
 }

 func introspectionHandler(introspector Introspector) func(http.ResponseWriter, *http.Request) {
@ -62,7 +63,7 @@ func ParseTokenIntrospectionRequest(r *http.Request, introspector Introspector)
 		return "", "", errors.New("unable to parse request")
 	}
 	if introspectorJWTProfile, ok := introspector.(IntrospectorJWTProfile); ok && req.ClientAssertion != "" {
-		profile, err := VerifyJWTAssertion(r.Context(), req.ClientAssertion, introspectorJWTProfile.JWTProfileVerifier())
+		profile, err := VerifyJWTAssertion(r.Context(), req.ClientAssertion, introspectorJWTProfile.JWTProfileVerifier(r.Context()))
 		if err == nil {
 			return req.Token, profile.Issuer, nil
 		}
--- a/pkg/op/token_jwt_profile.go
+++ b/pkg/op/token_jwt_profile.go
@ -11,7 +11,7 @@ import (

 type JWTAuthorizationGrantExchanger interface {
 	Exchanger
-	JWTProfileVerifier() JWTProfileVerifier
+	JWTProfileVerifier(context.Context) JWTProfileVerifier
 }

 //JWTProfile handles the OAuth 2.0 JWT Profile Authorization Grant https://tools.ietf.org/html/rfc7523#section-2.1
@ -21,7 +21,7 @@ func JWTProfile(w http.ResponseWriter, r *http.Request, exchanger JWTAuthorizati
 		RequestError(w, r, err)
 	}

-	tokenRequest, err := VerifyJWTAssertion(r.Context(), profileRequest.Assertion, exchanger.JWTProfileVerifier())
+	tokenRequest, err := VerifyJWTAssertion(r.Context(), profileRequest.Assertion, exchanger.JWTProfileVerifier(r.Context()))
 	if err != nil {
 		RequestError(w, r, err)
 		return
--- a/pkg/op/token_request.go
+++ b/pkg/op/token_request.go
@ -10,10 +10,8 @@ import (
 )

 type Exchanger interface {
-	Issuer() string
 	Storage() Storage
 	Decoder() httphelper.Decoder
-	Signer() Signer
 	Crypto() Crypto
 	AuthMethodPostSupported() bool
 	AuthMethodPrivateKeyJWTSupported() bool
@ -111,7 +109,7 @@ func AuthorizeCodeChallenge(tokenReq *oidc.AccessTokenRequest, challenge *oidc.C
 //AuthorizePrivateJWTKey authorizes a client by validating the client_assertion's signature with a previously
 //registered public key (JWT Profile)
 func AuthorizePrivateJWTKey(ctx context.Context, clientAssertion string, exchanger JWTAuthorizationGrantExchanger) (Client, error) {
-	jwtReq, err := VerifyJWTAssertion(ctx, clientAssertion, exchanger.JWTProfileVerifier())
+	jwtReq, err := VerifyJWTAssertion(ctx, clientAssertion, exchanger.JWTProfileVerifier(ctx))
 	if err != nil {
 		return nil, err
 	}
--- a/pkg/op/token_revocation.go
+++ b/pkg/op/token_revocation.go
@ -14,14 +14,14 @@ type Revoker interface {
 	Decoder() httphelper.Decoder
 	Crypto() Crypto
 	Storage() Storage
-	AccessTokenVerifier() AccessTokenVerifier
+	AccessTokenVerifier(context.Context) AccessTokenVerifier
 	AuthMethodPrivateKeyJWTSupported() bool
 	AuthMethodPostSupported() bool
 }

 type RevokerJWTProfile interface {
 	Revoker
-	JWTProfileVerifier() JWTProfileVerifier
+	JWTProfileVerifier(context.Context) JWTProfileVerifier
 }

 func revocationHandler(revoker Revoker) func(http.ResponseWriter, *http.Request) {
@ -67,7 +67,7 @@ func ParseTokenRevocationRequest(r *http.Request, revoker Revoker) (token, token
 		if !ok || !revoker.AuthMethodPrivateKeyJWTSupported() {
 			return "", "", "", oidc.ErrInvalidClient().WithDescription("auth_method private_key_jwt not supported")
 		}
-		profile, err := VerifyJWTAssertion(r.Context(), req.ClientAssertion, revokerJWTProfile.JWTProfileVerifier())
+		profile, err := VerifyJWTAssertion(r.Context(), req.ClientAssertion, revokerJWTProfile.JWTProfileVerifier(r.Context()))
 		if err == nil {
 			return req.Token, req.TokenTypeHint, profile.Issuer, nil
 		}
@ -128,7 +128,7 @@ func getTokenIDAndSubjectForRevocation(ctx context.Context, userinfoProvider Use
 		}
 		return splitToken[0], splitToken[1], true
 	}
-	accessTokenClaims, err := VerifyAccessToken(ctx, accessToken, userinfoProvider.AccessTokenVerifier())
+	accessTokenClaims, err := VerifyAccessToken(ctx, accessToken, userinfoProvider.AccessTokenVerifier(ctx))
 	if err != nil {
 		return "", "", false
 	}
--- a/pkg/op/userinfo.go
+++ b/pkg/op/userinfo.go
@ -14,7 +14,7 @@ type UserinfoProvider interface {
 	Decoder() httphelper.Decoder
 	Crypto() Crypto
 	Storage() Storage
-	AccessTokenVerifier() AccessTokenVerifier
+	AccessTokenVerifier(context.Context) AccessTokenVerifier
 }

 func userinfoHandler(userinfoProvider UserinfoProvider) func(http.ResponseWriter, *http.Request) {
@ -81,7 +81,7 @@ func getTokenIDAndSubject(ctx context.Context, userinfoProvider UserinfoProvider
 		}
 		return splitToken[0], splitToken[1], true
 	}
-	accessTokenClaims, err := VerifyAccessToken(ctx, accessToken, userinfoProvider.AccessTokenVerifier())
+	accessTokenClaims, err := VerifyAccessToken(ctx, accessToken, userinfoProvider.AccessTokenVerifier(ctx))
 	if err != nil {
 		return "", "", false
 	}