Add OAuth/OIDC authentication for remote MCP server registries

cmd/thv/app/config_registryauth.go

@@ -0,0 +1,78 @@
+// SPDX-FileCopyrightText: Copyright 2025 Stacklok, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package app
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"github.com/stacklok/toolhive/pkg/config"
+	"github.com/stacklok/toolhive/pkg/registry"
+)
+
+var (
+	authIssuer   string
+	authClientID string
+	authAudience string
+	authScopes   []string
+)
+
+var setRegistryAuthCmd = &cobra.Command{
+	Use:   "set-registry-auth",
+	Short: "Configure OAuth/OIDC authentication for the registry",
+	Long: `Configure OAuth/OIDC authentication for the remote MCP server registry.
+PKCE (S256) is always enforced for security.
+
+The issuer URL is validated via OIDC discovery before saving.
+
+Examples:
+  thv config set-registry-auth --issuer https://auth.company.com --client-id toolhive-cli
+  thv config set-registry-auth \
+    --issuer https://auth.company.com --client-id toolhive-cli \
+    --audience api://my-registry --scopes openid,profile`,
+	RunE: setRegistryAuthCmdFunc,
+}
+
+var unsetRegistryAuthCmd = &cobra.Command{
+	Use:   "unset-registry-auth",
+	Short: "Remove registry authentication configuration",
+	Long:  "Remove the OAuth/OIDC authentication configuration for the registry.",
+	RunE:  unsetRegistryAuthCmdFunc,
+}
+
+func init() {
+	setRegistryAuthCmd.Flags().StringVar(&authIssuer, "issuer", "", "OIDC issuer URL (required)")
+	setRegistryAuthCmd.Flags().StringVar(&authClientID, "client-id", "", "OAuth client ID (required)")
+	setRegistryAuthCmd.Flags().StringVar(&authAudience, "audience", "", "OAuth audience parameter")
+	setRegistryAuthCmd.Flags().StringSliceVar(
+		&authScopes, "scopes", []string{"openid", "offline_access"}, "OAuth scopes",
+	)
+
+	_ = setRegistryAuthCmd.MarkFlagRequired("issuer")
+	_ = setRegistryAuthCmd.MarkFlagRequired("client-id")
+
+	configCmd.AddCommand(setRegistryAuthCmd)
+	configCmd.AddCommand(unsetRegistryAuthCmd)
+}
+
+func setRegistryAuthCmdFunc(_ *cobra.Command, _ []string) error {
+	authManager := registry.NewAuthManager(config.NewDefaultProvider())
+
+	if err := authManager.SetOAuthAuth(authIssuer, authClientID, authAudience, authScopes); err != nil {
+		return fmt.Errorf("failed to configure registry auth: %w", err)
+	}
+
+	return nil
+}
+
+func unsetRegistryAuthCmdFunc(_ *cobra.Command, _ []string) error {
+	authManager := registry.NewAuthManager(config.NewDefaultProvider())
+
+	if err := authManager.UnsetAuth(); err != nil {
+		return fmt.Errorf("failed to remove registry auth: %w", err)
+	}
+
+	return nil
+}

pkg/config/config.go

@@ -45,6 +45,33 @@ type Config struct {
 	BuildEnvFromShell            []string                            `yaml:"build_env_from_shell,omitempty"`
 	BuildAuthFiles               map[string]string                   `yaml:"build_auth_files,omitempty"`
 	RuntimeConfigs               map[string]*templates.RuntimeConfig `yaml:"runtime_configs,omitempty"`
+	RegistryAuth                 RegistryAuth                        `yaml:"registry_auth,omitempty"`
+}
+
+// RegistryAuthTypeOAuth is the auth type for OAuth/OIDC authentication.
+const RegistryAuthTypeOAuth = "oauth"
+
+// RegistryAuth holds authentication configuration for remote registries.
+type RegistryAuth struct {
+	// Type is the authentication type: RegistryAuthTypeOAuth or "" (none).
+	Type string `yaml:"type,omitempty"`
+
+	// OAuth holds OAuth/OIDC authentication configuration.
+	OAuth *RegistryOAuthConfig `yaml:"oauth,omitempty"`
+}
+
+// RegistryOAuthConfig holds OAuth/OIDC configuration for registry authentication.
+// PKCE (S256) is always enforced per OAuth 2.1 requirements for public clients.
+type RegistryOAuthConfig struct {
+	Issuer       string   `yaml:"issuer"`
+	ClientID     string   `yaml:"client_id"`
+	Scopes       []string `yaml:"scopes,omitempty"`
+	Audience     string   `yaml:"audience,omitempty"`
+	CallbackPort int      `yaml:"callback_port,omitempty"`
+
+	// Cached token references for session restoration across CLI invocations.
+	CachedRefreshTokenRef string    `yaml:"cached_refresh_token_ref,omitempty"`
+	CachedTokenExpiry     time.Time `yaml:"cached_token_expiry,omitempty"`
 }
 
 // Secrets contains the settings for secrets management.

pkg/registry/api/client.go

@@ -17,6 +17,7 @@ import (
 	"gopkg.in/yaml.v3"
 
 	"github.com/stacklok/toolhive/pkg/networking"
+	"github.com/stacklok/toolhive/pkg/registry/auth"
 	"github.com/stacklok/toolhive/pkg/versions"
 )
 
@@ -56,8 +57,10 @@ type mcpRegistryClient struct {
 	userAgent      string
 }
 
-// NewClient creates a new MCP Registry API client
-func NewClient(baseURL string, allowPrivateIp bool) (Client, error) {
+// NewClient creates a new MCP Registry API client.
+// If tokenSource is non-nil, the HTTP client transport will be wrapped to inject
+// Bearer tokens into all requests.
+func NewClient(baseURL string, allowPrivateIp bool, tokenSource auth.TokenSource) (Client, error) {
 	// Build HTTP client with security controls
 	// If private IPs are allowed, also allow HTTP (for localhost testing)
 	builder := networking.NewHttpClientBuilder().WithPrivateIPs(allowPrivateIp)
@@ -69,6 +72,9 @@ func NewClient(baseURL string, allowPrivateIp bool) (Client, error) {
 		return nil, fmt.Errorf("failed to build HTTP client: %w", err)
 	}
 
+	// Wrap transport with auth if token source is provided
+	httpClient.Transport = auth.WrapTransport(httpClient.Transport, tokenSource)
+
 	// Ensure base URL doesn't have trailing slash
 	if baseURL[len(baseURL)-1] == '/' {
 		baseURL = baseURL[:len(baseURL)-1]

pkg/registry/auth/auth.go

@@ -0,0 +1,57 @@
+// SPDX-FileCopyrightText: Copyright 2025 Stacklok, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package auth provides authentication support for MCP server registries.
+package auth
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+
+	"github.com/stacklok/toolhive/pkg/config"
+	"github.com/stacklok/toolhive/pkg/secrets"
+)
+
+// ErrRegistryAuthRequired is returned when registry authentication is required
+// but no cached tokens are available in a non-interactive context.
+var ErrRegistryAuthRequired = errors.New("registry authentication required: run 'thv registry login' to authenticate")
+
+// TokenSource provides authentication tokens for registry HTTP requests.
+type TokenSource interface {
+	// Token returns a valid access token string, or empty string if no auth.
+	// Implementations should handle token refresh transparently.
+	Token(ctx context.Context) (string, error)
+}
+
+// NewTokenSource creates a TokenSource from registry OAuth configuration.
+// Returns nil, nil if oauth config is nil (no auth required).
+// The registryURL is used to derive a unique secret key for token storage.
+// The secrets provider may be nil if secret storage is not available.
+// The interactive flag controls whether browser-based OAuth flows are allowed.
+func NewTokenSource(
+	cfg *config.RegistryOAuthConfig,
+	registryURL string,
+	secretsProvider secrets.Provider,
+	interactive bool,
+) (TokenSource, error) {
+	if cfg == nil {
+		return nil, nil
+	}
+
+	return &oauthTokenSource{
+		oauthCfg:        cfg,
+		registryURL:     registryURL,
+		secretsProvider: secretsProvider,
+		interactive:     interactive,
+	}, nil
+}
+
+// DeriveSecretKey computes the secret key for storing a registry's refresh token.
+// The key follows the formula: REGISTRY_OAUTH_<8 hex chars>
+// where the hex is derived from sha256(registryURL + "\x00" + issuer)[:4].
+func DeriveSecretKey(registryURL, issuer string) string {
+	h := sha256.Sum256([]byte(registryURL + "\x00" + issuer))
+	return "REGISTRY_OAUTH_" + hex.EncodeToString(h[:4])
+}