From 600028fdd645806c737f25339de79e87eb8f6ae9 Mon Sep 17 00:00:00 2001
From: Henning Perl <henning.perl@ory.sh>
Date: Tue, 28 Jan 2025 13:46:01 +0100
Subject: [PATCH] add netid token claim support

---
 embedx/config.schema.json                     |  6 +++
 .../strategy/oidc/fedcm/definitions.go        |  3 ++
 selfservice/strategy/oidc/provider_config.go  |  4 ++
 selfservice/strategy/oidc/provider_netid.go   | 38 ++++++++++++++++---
 .../strategy/oidc/provider_netid_test.go      | 29 ++++++++++++++
 5 files changed, 74 insertions(+), 6 deletions(-)
 create mode 100644 selfservice/strategy/oidc/provider_netid_test.go

diff --git a/embedx/config.schema.json b/embedx/config.schema.json
index ad4db74df0e9..049de330a512 100644
--- a/embedx/config.schema.json
+++ b/embedx/config.schema.json
@@ -586,6 +586,12 @@
           "type": "string",
           "format": "uri",
           "examples": ["https://example.com/config.json"]
+        },
+        "net_id_token_origin_header": {
+          "title": "NetID Token Origin Header",
+          "description": "Contains the orgin header to be used when exchanging a NetID FedCM token for an ID token",
+          "type": "string",
+          "examples": ["https://example.com"]
         }
       },
       "additionalProperties": false,
diff --git a/selfservice/strategy/oidc/fedcm/definitions.go b/selfservice/strategy/oidc/fedcm/definitions.go
index a21c14a7b0eb..f72a6e676d9e 100644
--- a/selfservice/strategy/oidc/fedcm/definitions.go
+++ b/selfservice/strategy/oidc/fedcm/definitions.go
@@ -85,6 +85,9 @@ type SubmitFedcmTokenBody struct {
 }
 
 // swagger:parameters submitFedcmToken
+//
+//nolint:deadcode,unused
+//lint:ignore U1000 Used to generate Swagger and OpenAPI definitions
 type submitFedcmToken struct {
 	// in: body
 	// required: true
diff --git a/selfservice/strategy/oidc/provider_config.go b/selfservice/strategy/oidc/provider_config.go
index e27dd6db25fc..c9de47e3d799 100644
--- a/selfservice/strategy/oidc/provider_config.go
+++ b/selfservice/strategy/oidc/provider_config.go
@@ -132,6 +132,10 @@ type Configuration struct {
 	// FedCMConfigURL is the URL to the FedCM IdP configuration file.
 	// This is only effective in the Ory Network.
 	FedCMConfigURL string `json:"fedcm_config_url"`
+
+	// NetIDTokenOriginHeader contains the orgin header to be used when exchanging a
+	// NetID FedCM token for an ID token.
+	NetIDTokenOriginHeader string `json:"net_id_token_origin_header"`
 }
 
 func (p Configuration) Redir(public *url.URL) string {
diff --git a/selfservice/strategy/oidc/provider_netid.go b/selfservice/strategy/oidc/provider_netid.go
index 93e3f3532cea..5bbab1931e92 100644
--- a/selfservice/strategy/oidc/provider_netid.go
+++ b/selfservice/strategy/oidc/provider_netid.go
@@ -4,12 +4,14 @@
 package oidc
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/url"
 	"slices"
-	"testing"
+	"strings"
 
 	"github.com/coreos/go-oidc/v3/oidc"
 	"github.com/hashicorp/go-retryablehttp"
@@ -123,13 +125,37 @@ func (n *ProviderNetID) Verify(ctx context.Context, rawIDToken string) (*Claims,
 		return nil, err
 	}
 
+	req, err := retryablehttp.NewRequestWithContext(ctx, "POST", urlx.AppendPaths(n.brokerURL(), "/token").String(), strings.NewReader(url.Values{
+		"grant_type":  {"netid_fedcm"},
+		"fedcm_token": {rawIDToken},
+	}.Encode()))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Origin", n.config.NetIDTokenOriginHeader)
+	res, err := n.reg.HTTPClient(ctx).Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	token := struct {
+		IDToken string `json:"id_token"`
+	}{}
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := json.NewDecoder(bytes.NewBuffer(body)).Decode(&token); err != nil {
+		return nil, err
+	}
+
 	idToken, err := provider.VerifierContext(
 		n.withHTTPClientContext(ctx),
-		&oidc.Config{
-			ClientID:                   n.config.ClientID,
-			InsecureSkipSignatureCheck: testing.Testing(),
-		},
-	).Verify(ctx, rawIDToken)
+		&oidc.Config{ClientID: n.config.ClientID},
+	).Verify(ctx, token.IDToken)
 	if err != nil {
 		return nil, err
 	}
diff --git a/selfservice/strategy/oidc/provider_netid_test.go b/selfservice/strategy/oidc/provider_netid_test.go
new file mode 100644
index 000000000000..759bc663acbe
--- /dev/null
+++ b/selfservice/strategy/oidc/provider_netid_test.go
@@ -0,0 +1,29 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package oidc_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/ory/kratos/internal"
+	"github.com/ory/kratos/selfservice/strategy/oidc"
+)
+
+func TestNetidProvider(t *testing.T) {
+	t.Skip("can't test this automatically, because the token is only valid for a short time")
+	_, reg := internal.NewVeryFastRegistryWithoutDB(t)
+
+	p := oidc.NewProviderNetID(&oidc.Configuration{
+		ClientID: "9b56b26a-e93d-4fce-8f16-951a9858f23e",
+	}, reg)
+
+	rawToken := `...`
+
+	claims, err := p.(oidc.IDTokenVerifier).Verify(context.Background(), rawToken)
+	require.NoError(t, err)
+	require.NotNil(t, claims)
+}