feat(auth): OIDC/Keycloak SSO-Login (additiv) — v1.2.91

SSO per OpenID Connect (Authorization Code + PKCE) zusätzlich zum lokalen Login. - Regeln: kein Auto-Provisioning (E-Mail muss als User existieren), Rolle aus DB (nie aus Token), lokaler Login+TOTP unangetastet. - Migration 0040: oidc_settings (Singleton, client_secret_enc via secrets.Box) + users.oidc_subject. - internal/services/oidc: Settings-Repo (write-only Secret) + lazy go-oidc Client (testbarer Authenticator-Seam). - internal/handlers/oidc.go: GET/PUT /oidc/settings (admin), GET /auth/oidc/{settings,login,callback}. Flow-State (state/PKCE/nonce) stateless im 5-min signierten HttpOnly-Cookie (SameSite=Lax). email_verified erzwungen, opportunistisches sub-Linking, Session via setSessionCookie+Signer. - session.SignBlob/VerifyBlob; users.Get/SetOIDCSubject; main.go-Wiring. - Frontend: App.tsx /auth/me-Bootstrap (für Cookie-Session nach Callback), Login-SSO-Button + sso_error, Settings OIDC-Card, i18n de/en. - Tests (guarded EG_FWTEST_DSN): Secret-Roundtrip + Callback (Rolle-aus-DB, no_account, disabled, unverified, nonce, state). Deps: go-oidc/v3, x/oauth2. Scope v1: nur Login (kein SLO/Refresh). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-05 16:04:13 +02:00
parent f85552a475
commit 3a707e2e3f
18 changed files with 1326 additions and 8 deletions
--- a/internal/services/oidc/client.go
+++ b/internal/services/oidc/client.go
@@ -0,0 +1,181 @@
+package oidc
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+
+	gooidc "github.com/coreos/go-oidc/v3/oidc"
+	"golang.org/x/oauth2"
+)
+
+// Claims sind die aus dem ID-Token extrahierten Felder, die der Login-
+// Flow braucht. Bewusst minimal — Rolle kommt NIE aus dem Token.
+type Claims struct {
+	Subject       string
+	Email         string
+	EmailVerified bool
+	Nonce         string
+}
+
+// Authenticator ist der testbare Seam: Aufbau der Auth-URL und der
+// Code-Exchange inkl. ID-Token-Verifikation + Claim-Extraktion. Der
+// Handler hängt nur hieran, sodass Tests einen Fake injizieren können.
+type Authenticator interface {
+	// AuthCodeURL baut die Redirect-URL zum IdP (state + nonce + PKCE-Challenge).
+	AuthCodeURL(ctx context.Context, redirectURI, state, nonce, pkceVerifier string) (string, error)
+	// Exchange tauscht den Code (PKCE), verifiziert das ID-Token und gibt
+	// die Claims zurück. Prüft Issuer/Audience/Signatur/Expiry.
+	Exchange(ctx context.Context, redirectURI, code, pkceVerifier string) (*Claims, error)
+}
+
+// Client implementiert Authenticator gegen einen echten OIDC-Provider.
+// Provider+Verifier werden lazy aufgebaut und gecached; bei geänderten
+// Settings (Fingerprint) neu aufgebaut.
+type Client struct {
+	repo *Repo
+
+	mu       sync.Mutex
+	cacheKey string
+	provider *gooidc.Provider
+	verifier *gooidc.IDTokenVerifier
+}
+
+func NewClient(repo *Repo) *Client { return &Client{repo: repo} }
+
+// loaded baut (oder reused) Provider+Verifier aus den aktuellen Settings.
+// Cache-Key = Fingerprint(issuer, client_id, scopes); Rebuild bei Änderung.
+func (c *Client) loaded(ctx context.Context) (*gooidc.Provider, *gooidc.IDTokenVerifier, error) {
+	s, err := c.repo.Get(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	if !s.Enabled {
+		return nil, nil, ErrDisabled
+	}
+	if strings.TrimSpace(s.IssuerURL) == "" || strings.TrimSpace(s.ClientID) == "" {
+		return nil, nil, fmt.Errorf("oidc: issuer_url and client_id required")
+	}
+	key := fingerprint(s.IssuerURL, s.ClientID, s.Scopes)
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.provider == nil || c.cacheKey != key {
+		prov, err := gooidc.NewProvider(ctx, s.IssuerURL)
+		if err != nil {
+			return nil, nil, fmt.Errorf("oidc: discovery: %w", err)
+		}
+		c.provider = prov
+		c.verifier = prov.Verifier(&gooidc.Config{ClientID: s.ClientID})
+		c.cacheKey = key
+	}
+	return c.provider, c.verifier, nil
+}
+
+func (c *Client) oauthConfig(prov *gooidc.Provider, clientID, secret, redirectURI, scopes string) oauth2.Config {
+	return oauth2.Config{
+		ClientID:     clientID,
+		ClientSecret: secret,
+		Endpoint:     prov.Endpoint(),
+		RedirectURL:  redirectURI,
+		Scopes:       splitScopes(scopes),
+	}
+}
+
+// AuthCodeURL implementiert Authenticator.
+func (c *Client) AuthCodeURL(ctx context.Context, redirectURI, state, nonce, pkceVerifier string) (string, error) {
+	s, err := c.repo.Get(ctx)
+	if err != nil {
+		return "", err
+	}
+	prov, _, err := c.loaded(ctx)
+	if err != nil {
+		return "", err
+	}
+	secret, _ := c.repo.ClientSecret(ctx)
+	cfg := c.oauthConfig(prov, s.ClientID, secret, redirectURI, s.Scopes)
+	return cfg.AuthCodeURL(state,
+		gooidc.Nonce(nonce),
+		oauth2.S256ChallengeOption(pkceVerifier),
+	), nil
+}
+
+// Exchange implementiert Authenticator.
+func (c *Client) Exchange(ctx context.Context, redirectURI, code, pkceVerifier string) (*Claims, error) {
+	s, err := c.repo.Get(ctx)
+	if err != nil {
+		return nil, err
+	}
+	prov, verifier, err := c.loaded(ctx)
+	if err != nil {
+		return nil, err
+	}
+	secret, _ := c.repo.ClientSecret(ctx)
+	cfg := c.oauthConfig(prov, s.ClientID, secret, redirectURI, s.Scopes)
+
+	tok, err := cfg.Exchange(ctx, code, oauth2.VerifierOption(pkceVerifier))
+	if err != nil {
+		return nil, fmt.Errorf("oidc: code exchange: %w", err)
+	}
+	rawID, ok := tok.Extra("id_token").(string)
+	if !ok || rawID == "" {
+		return nil, errors.New("oidc: no id_token in response")
+	}
+	idToken, err := verifier.Verify(ctx, rawID)
+	if err != nil {
+		return nil, fmt.Errorf("oidc: id_token verify: %w", err)
+	}
+	return extractClaims(idToken, s.EmailClaim)
+}
+
+// extractClaims liest E-Mail (via konfigurierbarem Claim), email_verified,
+// sub und nonce aus dem verifizierten ID-Token.
+func extractClaims(idToken *gooidc.IDToken, emailClaim string) (*Claims, error) {
+	var raw map[string]any
+	if err := idToken.Claims(&raw); err != nil {
+		return nil, fmt.Errorf("oidc: decode claims: %w", err)
+	}
+	if emailClaim == "" {
+		emailClaim = "email"
+	}
+	out := &Claims{Subject: idToken.Subject}
+	if v, ok := raw[emailClaim].(string); ok {
+		out.Email = strings.TrimSpace(strings.ToLower(v))
+	}
+	// email_verified kann bool oder "true"/"false" sein.
+	switch ev := raw["email_verified"].(type) {
+	case bool:
+		out.EmailVerified = ev
+	case string:
+		out.EmailVerified = ev == "true"
+	}
+	if n, ok := raw["nonce"].(string); ok {
+		out.Nonce = n
+	}
+	return out, nil
+}
+
+func splitScopes(s string) []string {
+	out := []string{}
+	for _, p := range strings.Fields(s) {
+		if p != "" {
+			out = append(out, p)
+		}
+	}
+	if len(out) == 0 {
+		out = []string{gooidc.ScopeOpenID, "email", "profile"}
+	}
+	return out
+}
+
+func fingerprint(parts ...string) string {
+	h := sha256.New()
+	for _, p := range parts {
+		h.Write([]byte(p))
+		h.Write([]byte{0})
+	}
+	return hex.EncodeToString(h.Sum(nil))
+}
--- a/internal/services/oidc/settings.go
+++ b/internal/services/oidc/settings.go
@@ -0,0 +1,111 @@
+// Package oidc kapselt die OIDC/Keycloak-SSO-Konfiguration (Singleton-
+// Settings + verschlüsseltes Client-Secret) und einen lazy aufgebauten
+// OIDC-Provider/Verifier. Login-Flow-State ist stateless (signiertes
+// Cookie im Handler), daher hält dieses Paket keinen Request-State.
+package oidc
+
+import (
+	"context"
+	"errors"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"git.netcell-it.de/projekte/edgeguard-native/internal/models"
+	"git.netcell-it.de/projekte/edgeguard-native/internal/services/secrets"
+)
+
+// ErrDisabled signalisiert, dass OIDC nicht aktiviert/konfiguriert ist.
+var ErrDisabled = errors.New("oidc: not enabled")
+
+// Repo liest/schreibt die oidc_settings-Singleton-Row und ver-/entschlüsselt
+// das Client-Secret via secrets.Box.
+type Repo struct {
+	pool *pgxpool.Pool
+	box  *secrets.Box
+}
+
+func New(pool *pgxpool.Pool, box *secrets.Box) *Repo {
+	return &Repo{pool: pool, box: box}
+}
+
+// Get liefert die Settings (client_secret_enc als Bytes, NULL → nil).
+func (r *Repo) Get(ctx context.Context) (*models.OIDCSettings, error) {
+	var s models.OIDCSettings
+	if err := r.pool.QueryRow(ctx, `
+SELECT id, enabled, issuer_url, client_id, client_secret_enc,
+       scopes, email_claim, button_label, created_at, updated_at
+FROM oidc_settings WHERE id = 1`).Scan(
+		&s.ID, &s.Enabled, &s.IssuerURL, &s.ClientID, &s.ClientSecretEnc,
+		&s.Scopes, &s.EmailClaim, &s.ButtonLabel, &s.CreatedAt, &s.UpdatedAt,
+	); err != nil {
+		return nil, err
+	}
+	return &s, nil
+}
+
+// ClientSecret entschlüsselt das gespeicherte Client-Secret ("" wenn keins).
+func (r *Repo) ClientSecret(ctx context.Context) (string, error) {
+	s, err := r.Get(ctx)
+	if err != nil {
+		return "", err
+	}
+	if len(s.ClientSecretEnc) == 0 {
+		return "", nil
+	}
+	pt, err := r.box.Open(s.ClientSecretEnc)
+	if err != nil {
+		return "", err
+	}
+	return string(pt), nil
+}
+
+// HasSecret meldet, ob ein Client-Secret hinterlegt ist (für die Admin-UI,
+// ohne das Secret selbst preiszugeben).
+func (r *Repo) HasSecret(ctx context.Context) (bool, error) {
+	var present bool
+	err := r.pool.QueryRow(ctx,
+		`SELECT client_secret_enc IS NOT NULL FROM oidc_settings WHERE id = 1`).Scan(&present)
+	return present, err
+}
+
+// UpdateInput beschreibt eine Settings-Änderung. ClientSecret nutzt
+// write-only-Semantik: nil = unverändert, "" = löschen, sonst neu sealen.
+type UpdateInput struct {
+	Enabled      bool
+	IssuerURL    string
+	ClientID     string
+	Scopes       string
+	EmailClaim   string
+	ButtonLabel  string
+	ClientSecret *string
+}
+
+// Update schreibt die Settings. Das Secret wird nur angefasst, wenn
+// ClientSecret != nil.
+func (r *Repo) Update(ctx context.Context, in UpdateInput) error {
+	if in.ClientSecret == nil {
+		_, err := r.pool.Exec(ctx, `
+UPDATE oidc_settings
+   SET enabled=$1, issuer_url=$2, client_id=$3, scopes=$4,
+       email_claim=$5, button_label=$6, updated_at=NOW()
+ WHERE id=1`,
+			in.Enabled, in.IssuerURL, in.ClientID, in.Scopes, in.EmailClaim, in.ButtonLabel)
+		return err
+	}
+
+	var enc []byte
+	if *in.ClientSecret != "" {
+		sealed, err := r.box.Seal([]byte(*in.ClientSecret))
+		if err != nil {
+			return err
+		}
+		enc = sealed
+	}
+	_, err := r.pool.Exec(ctx, `
+UPDATE oidc_settings
+   SET enabled=$1, issuer_url=$2, client_id=$3, scopes=$4,
+       email_claim=$5, button_label=$6, client_secret_enc=$7, updated_at=NOW()
+ WHERE id=1`,
+		in.Enabled, in.IssuerURL, in.ClientID, in.Scopes, in.EmailClaim, in.ButtonLabel, enc)
+	return err
+}
--- a/internal/services/oidc/settings_test.go
+++ b/internal/services/oidc/settings_test.go
@@ -0,0 +1,90 @@
+package oidc
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"git.netcell-it.de/projekte/edgeguard-native/internal/database"
+	"git.netcell-it.de/projekte/edgeguard-native/internal/services/secrets"
+)
+
+// migrateRetry umgeht die goose-Erst-Apply-Race, wenn mehrere guarded
+// Test-Pakete dieselbe frische DB parallel migrieren.
+func migrateRetry(ctx context.Context, dsn string) error {
+	var err error
+	for i := 0; i < 3; i++ {
+		if err = database.Migrate(ctx, dsn); err == nil {
+			return nil
+		}
+		time.Sleep(700 * time.Millisecond)
+	}
+	return err
+}
+
+// Guarded integration test: set EG_FWTEST_DSN (sonst skip).
+func testRepo(t *testing.T) *Repo {
+	t.Helper()
+	dsn := os.Getenv("EG_FWTEST_DSN")
+	if dsn == "" {
+		t.Skip("set EG_FWTEST_DSN to run the oidc settings test")
+	}
+	ctx := context.Background()
+	if err := migrateRetry(ctx, dsn); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	pool, err := database.Open(ctx, dsn)
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	t.Cleanup(pool.Close)
+	box := secrets.New(t.TempDir() + "/master_key")
+	// Settings auf einen sauberen Default zurücksetzen.
+	if _, err := pool.Exec(ctx, `UPDATE oidc_settings SET enabled=false, issuer_url='', client_id='', client_secret_enc=NULL WHERE id=1`); err != nil {
+		t.Fatalf("reset: %v", err)
+	}
+	return New(pool, box)
+}
+
+func TestSettings_SecretWriteOnly(t *testing.T) {
+	r := testRepo(t)
+	ctx := context.Background()
+	str := func(s string) *string { return &s }
+
+	// 1) Neues Secret setzen.
+	if err := r.Update(ctx, UpdateInput{Enabled: true, IssuerURL: "https://idp.example/realms/x", ClientID: "eg", ClientSecret: str("s3cr3t")}); err != nil {
+		t.Fatal(err)
+	}
+	if has, _ := r.HasSecret(ctx); !has {
+		t.Fatal("HasSecret should be true after setting a secret")
+	}
+	got, err := r.ClientSecret(ctx)
+	if err != nil || got != "s3cr3t" {
+		t.Fatalf("ClientSecret = %q, %v; want s3cr3t", got, err)
+	}
+
+	// 2) Update mit nil → Secret bleibt unverändert.
+	if err := r.Update(ctx, UpdateInput{Enabled: true, IssuerURL: "https://idp.example/realms/x", ClientID: "eg2", ClientSecret: nil}); err != nil {
+		t.Fatal(err)
+	}
+	got, _ = r.ClientSecret(ctx)
+	if got != "s3cr3t" {
+		t.Fatalf("secret should be preserved on nil update, got %q", got)
+	}
+	if s, _ := r.Get(ctx); s.ClientID != "eg2" {
+		t.Fatalf("client_id should update to eg2, got %q", s.ClientID)
+	}
+
+	// 3) Update mit "" → Secret gelöscht.
+	if err := r.Update(ctx, UpdateInput{Enabled: false, IssuerURL: "", ClientID: "", ClientSecret: str("")}); err != nil {
+		t.Fatal(err)
+	}
+	if has, _ := r.HasSecret(ctx); has {
+		t.Fatal("HasSecret should be false after clearing the secret")
+	}
+	got, _ = r.ClientSecret(ctx)
+	if got != "" {
+		t.Fatalf("secret should be empty after clear, got %q", got)
+	}
+}
--- a/internal/services/session/session.go
+++ b/internal/services/session/session.go
@@ -174,3 +174,67 @@ var (
 	ErrInvalidToken = errors.New("invalid session token")
 	ErrExpiredToken = errors.New("session token expired")
 )
+
+// blobEnvelope umhüllt eine beliebige Payload mit einem Ablaufzeitpunkt.
+type blobEnvelope struct {
+	Exp     int64  `json:"exp"`
+	Payload []byte `json:"p"`
+}
+
+// SignBlob signiert beliebige Bytes mit dem Session-Secret (HMAC-SHA256,
+// gleiches Format wie Tokens: base64url(json).base64url(sig)) und einer
+// TTL. Für stateless, cluster-sichere Kurzzeit-Cookies (z.B. der
+// OIDC-Flow-State). Das Secret ist clusterweit synchron (.jwt_fingerprint).
+func (s *Signer) SignBlob(payload []byte, ttl time.Duration) (string, error) {
+	env := blobEnvelope{
+		Exp:     s.Now().Add(ttl).Unix(),
+		Payload: payload,
+	}
+	data, err := json.Marshal(env)
+	if err != nil {
+		return "", err
+	}
+	mac := hmac.New(sha256.New, s.Secret)
+	mac.Write(data)
+	return base64.RawURLEncoding.EncodeToString(data) + "." +
+		base64.RawURLEncoding.EncodeToString(mac.Sum(nil)), nil
+}
+
+// VerifyBlob prüft Signatur + Ablauf und gibt die ursprüngliche Payload
+// zurück. ErrInvalidToken / ErrExpiredToken bei Fehlern.
+func (s *Signer) VerifyBlob(raw string) ([]byte, error) {
+	if raw == "" {
+		return nil, ErrInvalidToken
+	}
+	dot := -1
+	for i := 0; i < len(raw); i++ {
+		if raw[i] == '.' {
+			dot = i
+			break
+		}
+	}
+	if dot <= 0 || dot >= len(raw)-1 {
+		return nil, ErrInvalidToken
+	}
+	payload, err := base64.RawURLEncoding.DecodeString(raw[:dot])
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+	sig, err := base64.RawURLEncoding.DecodeString(raw[dot+1:])
+	if err != nil {
+		return nil, ErrInvalidToken
+	}
+	mac := hmac.New(sha256.New, s.Secret)
+	mac.Write(payload)
+	if subtle.ConstantTimeCompare(mac.Sum(nil), sig) != 1 {
+		return nil, ErrInvalidToken
+	}
+	var env blobEnvelope
+	if err := json.Unmarshal(payload, &env); err != nil {
+		return nil, ErrInvalidToken
+	}
+	if s.Now().Unix() >= env.Exp {
+		return nil, ErrExpiredToken
+	}
+	return env.Payload, nil
+}
--- a/internal/services/users/users.go
+++ b/internal/services/users/users.go
@@ -240,6 +240,21 @@ func (r *Repo) RecordLogin(ctx context.Context, id int64) {
 	_, _ = r.pool.Exec(ctx, `UPDATE users SET last_login_at=NOW() WHERE id=$1`, id)
 }

+// GetOIDCSubject liefert den gespeicherten OIDC-'sub' des Users ("" wenn
+// noch nicht verknüpft).
+func (r *Repo) GetOIDCSubject(ctx context.Context, id int64) (string, error) {
+	var sub string
+	err := r.pool.QueryRow(ctx, `SELECT COALESCE(oidc_subject, '') FROM users WHERE id=$1`, id).Scan(&sub)
+	return sub, err
+}
+
+// SetOIDCSubject speichert den OIDC-'sub' beim ersten erfolgreichen
+// SSO-Login (opportunistisches Linking).
+func (r *Repo) SetOIDCSubject(ctx context.Context, id int64, sub string) error {
+	_, err := r.pool.Exec(ctx, `UPDATE users SET oidc_subject=$1, updated_at=NOW() WHERE id=$2`, sub, id)
+	return err
+}
+
 // VerifyPassword is a constant-time bcrypt compare.
 func VerifyPassword(hash, password string) bool {
 	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password)) == nil