feat(auth): Implement GitHub OAuth authentication flow for package publishing

- Added authentication service and GitHub OAuth integration.
- Introduced new authentication methods and structures in the model.
- Updated the API to handle authentication during the publishing process.
- Created handlers for starting and checking the status of the OAuth flow.
- Enhanced the publish handler to validate authentication credentials.
- Updated configuration to include GitHub OAuth settings.
- Added tests for the OAuth flow and publishing with authentication.
- Updated documentation to reflect changes in the API and authentication process.

internal/auth/auth.go

@@ -0,0 +1,28 @@
+// Package auth provides authentication mechanisms for the MCP registry
+package auth
+
+import (
+	"context"
+	"errors"
+
+	"github.com/modelcontextprotocol/registry/internal/model"
+)
+
+var (
+	// ErrAuthRequired is returned when authentication is required but not provided
+	ErrAuthRequired = errors.New("authentication required")
+	// ErrUnsupportedAuthMethod is returned when an unsupported auth method is used
+	ErrUnsupportedAuthMethod = errors.New("unsupported authentication method")
+)
+
+// Service defines the authentication service interface
+type Service interface {
+	// StartAuthFlow initiates an authentication flow and returns the flow information
+	StartAuthFlow(ctx context.Context, method model.AuthMethod, repoRef string) (map[string]string, string, error)
+
+	// CheckAuthStatus checks the status of an authentication flow using a status token
+	CheckAuthStatus(ctx context.Context, statusToken string) (string, error)
+
+	// ValidateAuth validates the authentication credentials
+	ValidateAuth(ctx context.Context, auth model.Authentication) (bool, error)
+}

internal/auth/github.go

@@ -0,0 +1,158 @@
+// Package auth provides authentication mechanisms for the MCP registry
+package auth
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"regexp"
+)
+
+const (
+	GitHubValidateTokenURL = "https://api.github.com/applications/CLIENT_ID/token"
+)
+
+var (
+	// ErrAuthFailed is returned when authentication fails
+	ErrAuthFailed = errors.New("authentication failed")
+	// ErrInvalidToken is returned when a token is invalid
+	ErrInvalidToken = errors.New("invalid token")
+	// ErrMissingScope is returned when a token doesn't have the required scope
+	ErrMissingScope = errors.New("token missing required scope")
+)
+
+// GitHubOAuthConfig holds the configuration for GitHub OAuth
+type GitHubOAuthConfig struct {
+	ClientID     string
+	ClientSecret string
+}
+
+// DeviceCodeResponse represents the response from GitHub's device code endpoint
+type DeviceCodeResponse struct {
+	DeviceCode      string `json:"device_code"`
+	UserCode        string `json:"user_code"`
+	VerificationURI string `json:"verification_uri"`
+	ExpiresIn       int    `json:"expires_in"`
+	Interval        int    `json:"interval"`
+}
+
+// AccessTokenResponse represents the response from GitHub's access token endpoint
+type AccessTokenResponse struct {
+	AccessToken string `json:"access_token"`
+	TokenType   string `json:"token_type"`
+	Scope       string `json:"scope"`
+	Error       string `json:"error,omitempty"`
+}
+
+// TokenValidationResponse represents the response from GitHub's token validation endpoint
+type TokenValidationResponse struct {
+	ID          int      `json:"id"`
+	URL         string   `json:"url"`
+	Scopes      []string `json:"scopes"`
+	SingleFile  string   `json:"single_file,omitempty"`
+	Repository  string   `json:"repository,omitempty"`
+	Fingerprint string   `json:"fingerprint,omitempty"`
+	Error       string   `json:"error,omitempty"`
+}
+
+// GitHubDeviceAuth provides methods for GitHub device OAuth authentication
+type GitHubDeviceAuth struct {
+	config GitHubOAuthConfig
+}
+
+// NewGitHubDeviceAuth creates a new GitHub device auth instance
+func NewGitHubDeviceAuth(config GitHubOAuthConfig) *GitHubDeviceAuth {
+	return &GitHubDeviceAuth{
+		config: config,
+	}
+}
+
+// ValidateToken checks if a token has write:packages access to the required repository
+func (g *GitHubDeviceAuth) ValidateToken(token string, requiredRepo string) (bool, error) {
+	// If no repo is required, we can't validate properly
+	if requiredRepo == "" {
+		return false, fmt.Errorf("repository reference is required for token validation")
+	}
+
+	// First, check if the token is valid using the app token check endpoint
+	req, err := http.NewRequest("POST", GitHubValidateTokenURL, bytes.NewBuffer([]byte(`{"access_token": "`+token+`"}`)))
+	if err != nil {
+		return false, err
+	}
+
+	req.URL.Path = fmt.Sprintf("/applications/%s/token", g.config.ClientID)
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+	req.SetBasicAuth(g.config.ClientID, g.config.ClientSecret)
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return false, err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return false, err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return false, fmt.Errorf("token validation failed: %s", body)
+	}
+
+	var validationResp TokenValidationResponse
+	err = json.Unmarshal(body, &validationResp)
+	if err != nil {
+		return false, err
+	}
+
+	// Now check if the token has permissions to the specific repository
+	// Use the GitHub API to check repository-specific permissions
+	repoCheckURL := fmt.Sprintf("https://api.github.com/repos/%s", requiredRepo)
+	repoReq, err := http.NewRequest("GET", repoCheckURL, nil)
+	if err != nil {
+		return false, err
+	}
+
+	repoReq.Header.Set("Accept", "application/vnd.github+json")
+	repoReq.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+
+	repoResp, err := client.Do(repoReq)
+	if err != nil {
+		return false, err
+	}
+	defer repoResp.Body.Close()
+
+	// Read and check response
+	if repoResp.StatusCode != http.StatusOK {
+		return false, fmt.Errorf("token does not have access to repository: %s (status: %d)", requiredRepo, repoResp.StatusCode)
+	}
+
+	// If we've reached this point, the token has access the repo
+	return true, nil
+}
+
+func (g *GitHubDeviceAuth) ExtractGitHubRepoFromName(n string) (owner, repo string, err error) {
+	// match io.github.<owner>/<repo>
+	regexp := regexp.MustCompile(`io\.github\.([^/]+)/([^/]+)`)
+	matches := regexp.FindStringSubmatch(n)
+	if len(matches) != 3 {
+		return "", "", fmt.Errorf("invalid GitHub repository name: %s", n)
+	}
+	return matches[1], matches[2], nil
+}
+
+// extractGitHubRepo extracts the owner and repository name from a GitHub repository URL
+func (g *GitHubDeviceAuth) ExtractGitHubRepo(repoURL string) (owner, repo string, err error) {
+	regexp := regexp.MustCompile(`github\.com/([^/]+)/([^/]+)`)
+	matches := regexp.FindStringSubmatch(repoURL)
+	if len(matches) != 3 {
+		return "", "", fmt.Errorf("invalid GitHub repository URL: %s", repoURL)
+	}
+	return matches[1], matches[2], nil
+}

internal/auth/service.go

@@ -0,0 +1,67 @@
+package auth
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/modelcontextprotocol/registry/internal/config"
+	"github.com/modelcontextprotocol/registry/internal/model"
+)
+
+// AuthServiceImpl implements the Service interface
+type AuthServiceImpl struct {
+	config     *config.Config
+	githubAuth *GitHubDeviceAuth
+}
+
+// NewAuthService creates a new authentication service
+func NewAuthService(cfg *config.Config) Service {
+	githubConfig := GitHubOAuthConfig{
+		ClientID:     cfg.GithubClientID,
+		ClientSecret: cfg.GithubClientSecret,
+	}
+
+	return &AuthServiceImpl{
+		config:     cfg,
+		githubAuth: NewGitHubDeviceAuth(githubConfig),
+	}
+}
+
+func (s *AuthServiceImpl) StartAuthFlow(ctx context.Context, method model.AuthMethod, repoRef string) (map[string]string, string, error) {
+	// return not implemented error
+	return nil, "", fmt.Errorf("not implemented")
+}
+
+func (s *AuthServiceImpl) CheckAuthStatus(ctx context.Context, statusToken string) (string, error) {
+	// return not implemented error
+	return "", fmt.Errorf("not implemented")
+}
+
+// ValidateAuth validates authentication credentials
+func (s *AuthServiceImpl) ValidateAuth(ctx context.Context, auth model.Authentication) (bool, error) {
+	// If authentication is not required, allow access
+	if !s.config.RequireAuth {
+		return true, nil
+	}
+
+	// If authentication is required but not provided
+	if auth.Method == "" || auth.Method == model.AuthMethodNone {
+		return false, ErrAuthRequired
+	}
+
+	switch auth.Method {
+	case model.AuthMethodGitHub:
+		// Extract repo reference from the repository URL if it's not provided
+		owner, repo, err := s.githubAuth.ExtractGitHubRepoFromName(auth.RepoRef)
+		if err != nil {
+			return false, err
+		}
+		repoRef := fmt.Sprintf("%s/%s", owner, repo)
+		if repoRef == "" {
+			return false, fmt.Errorf("repository reference is required for GitHub authentication")
+		}
+		return s.githubAuth.ValidateToken(auth.Token, repoRef)
+	default:
+		return false, ErrUnsupportedAuthMethod
+	}
+}