openid: Allow promp=none for https/localhost

handler/openid/validator.go

@@ -74,12 +74,10 @@ func (v *OpenIDConnectRequestValidator) ValidatePrompt(ctx context.Context, req
 		//  unless the identity of the client can be proven, the request SHOULD
 		//  be processed as if no previous request had been approved.
 
-		// To make sure that we are not vulnerable to this type of attack, we will always require consent for public
-		// clients.
-
-		// If prompt is none - meaning that no consent should be requested, we must terminate with an error.
 		if stringslice.Has(prompt, "none") {
-			return errors.WithStack(fosite.ErrConsentRequired.WithHint("OAuth 2.0 Client is marked public and requires end-user consent, but \"prompt=none\" was requested."))
+			if !(req.GetRedirectURI().Scheme == "https" || (fosite.IsLocalhost(req.GetRedirectURI()) && req.GetRedirectURI().Scheme == "http")) {
+				return errors.WithStack(fosite.ErrConsentRequired.WithHint("OAuth 2.0 Client is marked public and redirect uri is not considered secure (https missing), but \"prompt=none\" was requested."))
+			}
 		}
 	}
 

handler/openid/validator_test.go

@@ -47,22 +47,54 @@ func TestValidatePrompt(t *testing.T) {
 	for k, tc := range []struct {
 		d           string
 		prompt      string
+		redirectURL string
 		isPublic    bool
 		expectErr   bool
 		idTokenHint string
 		s           *DefaultSession
 	}{
 		{
-			d:         "should fail because prompt=none should not work together with public clients",
-			prompt:    "none",
-			isPublic:  true,
-			expectErr: true,
+			d:           "should fail because prompt=none should not work together with public clients and non-http-localhost",
+			prompt:      "none",
+			isPublic:    true,
+			expectErr:   true,
+			redirectURL: "http://foo-bar/",
 			s: &DefaultSession{
 				Subject: "foo",
 				Claims: &jwt.IDTokenClaims{
 					Subject:     "foo",
 					RequestedAt: time.Now().UTC(),
-					AuthTime:    time.Now().UTC(),
+					AuthTime:    time.Now().UTC().Add(-time.Minute),
+				},
+			},
+		},
+		{
+			d:           "should fail because prompt=none should not work together with public clients",
+			prompt:      "none",
+			isPublic:    true,
+			expectErr:   false,
+			redirectURL: "http://localhost/",
+			s: &DefaultSession{
+				Subject: "foo",
+				Claims: &jwt.IDTokenClaims{
+					Subject:     "foo",
+					RequestedAt: time.Now().UTC(),
+					AuthTime:    time.Now().UTC().Add(-time.Minute),
+				},
+			},
+		},
+		{
+			d:           "should pass",
+			prompt:      "none",
+			isPublic:    true,
+			expectErr:   false,
+			redirectURL: "https://foo-bar/",
+			s: &DefaultSession{
+				Subject: "foo",
+				Claims: &jwt.IDTokenClaims{
+					Subject:     "foo",
+					RequestedAt: time.Now().UTC(),
+					AuthTime:    time.Now().UTC().Add(-time.Minute),
 				},
 			},
 		},
@@ -230,6 +262,7 @@ func TestValidatePrompt(t *testing.T) {
 					Client:  &fosite.DefaultClient{Public: tc.isPublic},
 					Session: tc.s,
 				},
+				RedirectURI: parse(tc.redirectURL),
 			})
 			if tc.expectErr {
 				assert.Error(t, err)
@@ -239,3 +272,8 @@ func TestValidatePrompt(t *testing.T) {
 		})
 	}
 }
+
+func parse(u string) *url.URL {
+	o, _ := url.Parse(u)
+	return o
+}