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/api/handlers/v0/auth.go

@@ -0,0 +1,117 @@
+// Package v0 contains API handlers for version 0 of the API
+package v0
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/modelcontextprotocol/registry/internal/auth"
+	"github.com/modelcontextprotocol/registry/internal/model"
+)
+
+// StartAuthHandler handles requests to start an authentication flow
+func StartAuthHandler(authService auth.Service) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		// Only allow POST method
+		if r.Method != http.MethodPost {
+			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+
+		// Read the request body
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			http.Error(w, "Error reading request body", http.StatusBadRequest)
+			return
+		}
+		defer r.Body.Close()
+
+		// Parse request body into AuthRequest struct
+		var authReq struct {
+			Method  string `json:"method"`
+			RepoRef string `json:"repo_ref"`
+		}
+		err = json.Unmarshal(body, &authReq)
+		if err != nil {
+			http.Error(w, "Invalid request payload: "+err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		// Validate required fields
+		if authReq.Method == "" {
+			http.Error(w, "Auth method is required", http.StatusBadRequest)
+			return
+		}
+
+		// Convert string method to enum type
+		var method model.AuthMethod
+		switch authReq.Method {
+		case "github":
+			method = model.AuthMethodGitHub
+		default:
+			http.Error(w, "Unsupported authentication method", http.StatusBadRequest)
+			return
+		}
+
+		// Start auth flow
+		flowInfo, statusToken, err := authService.StartAuthFlow(r.Context(), method, authReq.RepoRef)
+		if err != nil {
+			http.Error(w, "Failed to start auth flow: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		// Return successful response
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"flow_info":    flowInfo,
+			"status_token": statusToken,
+			"expires_in":   300, // 5 minutes
+		})
+	}
+}
+
+// CheckAuthStatusHandler handles requests to check the status of an authentication flow
+func CheckAuthStatusHandler(authService auth.Service) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		// Only allow GET method
+		if r.Method != http.MethodGet {
+			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+
+		// Get status token from query parameter
+		statusToken := r.URL.Query().Get("token")
+		if statusToken == "" {
+			http.Error(w, "Status token is required", http.StatusBadRequest)
+			return
+		}
+
+		// Check auth status
+		token, err := authService.CheckAuthStatus(r.Context(), statusToken)
+		if err != nil {
+			if err.Error() == "pending" {
+				// Auth is still pending
+				w.Header().Set("Content-Type", "application/json")
+				w.WriteHeader(http.StatusOK)
+				json.NewEncoder(w).Encode(map[string]interface{}{
+					"status": "pending",
+				})
+				return
+			}
+
+			// Other error
+			http.Error(w, "Failed to check auth status: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		// Authentication completed successfully
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"status": "complete",
+			"token":  token,
+		})
+	}
+}

internal/api/handlers/v0/publish.go

@@ -6,12 +6,24 @@ import (
 	"io"
 	"net/http"
 
+	"github.com/modelcontextprotocol/registry/internal/auth"
 	"github.com/modelcontextprotocol/registry/internal/model"
 	"github.com/modelcontextprotocol/registry/internal/service"
 )
 
+// httpError represents an HTTP error with a message and status code
+type httpError struct {
+	msg    string
+	status int
+}
+
+// Error returns the error message
+func (e *httpError) Error() string {
+	return e.msg
+}
+
 // PublishHandler handles requests to publish new server details to the registry
-func PublishHandler(registry service.RegistryService) http.HandlerFunc {
+func PublishHandler(registry service.RegistryService, authService auth.Service) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		// Only allow POST method
 		if r.Method != http.MethodPost {
@@ -27,26 +39,48 @@ func PublishHandler(registry service.RegistryService) http.HandlerFunc {
 		}
 		defer r.Body.Close()
 
-		// Parse request body into ServerDetail struct
-		var serverDetail model.ServerDetail
-		err = json.Unmarshal(body, &serverDetail)
+		// Parse request body into PublishRequest struct
+		var publishReq model.PublishRequest
+		err = json.Unmarshal(body, &publishReq)
 		if err != nil {
-			http.Error(w, "Invalid request payload", http.StatusBadRequest)
+			http.Error(w, "Invalid request payload: "+err.Error(), http.StatusBadRequest)
 			return
 		}
 
+		// Get server details from the request
+		serverDetail := publishReq.ServerDetail
+
 		// Validate required fields
 		if serverDetail.Name == "" {
 			http.Error(w, "Name is required", http.StatusBadRequest)
 			return
 		}
 
-		// version is required
+		// Version is required
 		if serverDetail.VersionDetail.Version == "" {
 			http.Error(w, "Version is required", http.StatusBadRequest)
 			return
 		}
 
+		// Validate authentication credentials
+		if authService != nil {
+			publishReq.Authentication.RepoRef = serverDetail.Name
+			valid, err := authService.ValidateAuth(r.Context(), publishReq.Authentication)
+			if err != nil {
+				if err == auth.ErrAuthRequired {
+					http.Error(w, "Authentication is required for publishing", http.StatusUnauthorized)
+					return
+				}
+				http.Error(w, "Authentication failed: "+err.Error(), http.StatusUnauthorized)
+				return
+			}
+
+			if !valid {
+				http.Error(w, "Invalid authentication credentials", http.StatusUnauthorized)
+				return
+			}
+		}
+
 		// Call the publish method on the registry service
 		err = registry.Publish(&serverDetail)
 		if err != nil {