feat!: replace global secret parameter with auto-generated secret (#6)

* feat!: replace global secret parameter with auto-generated secret

- Remove GLOBAL_SECRET environment variable and command line flag
- Add LoadOrGenerateSecret function to automatically generate and persist secrets
- Update documentation to remove global secret references
- Add developer guidelines for conventional commits

BREAKING CHANGE: GLOBAL_SECRET environment variable and --global-secret flag are no longer supported. Secrets are now automatically generated and persisted.

* Update pkg/utils/keys.go

Co-authored-by: Copilot <[email protected]>

* refactor: extract secret size to named constant

Replace magic number 32 with SecretSize constant for better maintainability.

---------

Co-authored-by: Copilot <[email protected]>

Author: hrntknr

README.md

@@ -10,7 +10,6 @@ If this project saves you time, please give it a star — it really helps visibi
 docker run --rm -p 80:80 --net=host \
   -e EXTERNAL_URL=http://localhost \
   -e PROXY_URL=http://localhost:8080 \
-  -e GLOBAL_SECRET=$(openssl rand -hex 32) \
   -e PASSWORD=changeme \
   -v ./data:/data \
   ghcr.io/sigbit/mcp-auth-proxy:latest
@@ -53,7 +52,6 @@ For a simpler approach to publish local MCP servers over OAuth, consider [MCP Wa
 | `DATA_PATH`            | No       | Data directory path                              | `./data`                                         |
 | `EXTERNAL_URL`         | No       | External URL for OAuth callbacks                 | `http://localhost`                               |
 | `PROXY_URL`            | No       | Target MCP server URL                            | `http://localhost:8080`                          |
-| `GLOBAL_SECRET`        | No       | Global secret for session encryption             | `supersecret`                                    |
 | `GOOGLE_CLIENT_ID`     | No       | Google OAuth client ID                           | -                                                |
 | `GOOGLE_CLIENT_SECRET` | No       | Google OAuth client secret                       | -                                                |
 | `GOOGLE_ALLOWED_USERS` | No       | Comma-separated list of allowed Google emails    | -                                                |
@@ -87,7 +85,6 @@ Download the latest binary from [releases](https://github.com/sigbit/mcp-auth-pr
 ./mcp-auth-proxy \
   --external-url "http://localhost:8081" \
   --proxy-url "http://localhost:8080" \
-  --global-secret "$(openssl rand -hex 32)" \
   --google-client-id "your-google-client-id" \
   --google-client-secret "your-google-client-secret" \
   --google-allowed-users "[email protected],[email protected]" \
@@ -103,7 +100,6 @@ Download the latest binary from [releases](https://github.com/sigbit/mcp-auth-pr
 docker run --rm -p 8081:8081 --net=host \
   -e EXTERNAL_URL=http://localhost:8081 \
   -e PROXY_URL=http://localhost:8080 \
-  -e GLOBAL_SECRET=$(openssl rand -hex 32) \
   -e GOOGLE_CLIENT_ID="your-google-client-id" \
   -e GOOGLE_CLIENT_SECRET="your-google-client-secret" \
   -e GOOGLE_ALLOWED_USERS="[email protected],[email protected]" \
@@ -114,3 +110,51 @@ docker run --rm -p 8081:8081 --net=host \
   -v ./data:/data \
   ghcr.io/sigbit/mcp-auth-proxy:latest
 ```
+
+## 👨‍💻 For Developers
+
+### Commit Message Guidelines
+
+This project follows [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) specification for commit messages. This helps with automated versioning, changelog generation, and makes the commit history more readable.
+
+#### Format
+
+```
+<type>[optional scope]: <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+#### Types
+
+- **feat**: A new feature
+- **fix**: A bug fix
+- **docs**: Documentation only changes
+- **style**: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
+- **refactor**: A code change that neither fixes a bug nor adds a feature
+- **perf**: A code change that improves performance
+- **test**: Adding missing tests or correcting existing tests
+- **build**: Changes that affect the build system or external dependencies
+- **ci**: Changes to our CI configuration files and scripts
+- **chore**: Other changes that don't modify src or test files
+- **revert**: Reverts a previous commit
+
+#### Examples
+
+```
+feat: add GitHub OAuth provider support
+fix: resolve token expiration handling
+docs: update OAuth setup instructions
+refactor: simplify authentication middleware
+ci: add automated release workflow
+```
+
+#### Breaking Changes
+
+Breaking changes should be indicated by a `!` after the type/scope:
+
+```
+feat!: change authentication API to support multiple providers
+```

main.go

@@ -34,7 +34,6 @@ func main() {
 	var dataPath string
 	var externalURL string
 	var proxyURL string
-	var globalSecret string
 	var googleClientID string
 	var googleClientSecret string
 	var googleAllowedUsers string
@@ -72,7 +71,6 @@ func main() {
 				dataPath,
 				externalURL,
 				proxyURL,
-				globalSecret,
 				googleClientID,
 				googleClientSecret,
 				googleAllowedUsersList,
@@ -95,7 +93,6 @@ func main() {
 	rootCmd.Flags().StringVarP(&dataPath, "data", "d", getEnvWithDefault("DATA_PATH", "./data"), "Path to the data directory")
 	rootCmd.Flags().StringVarP(&externalURL, "external-url", "e", getEnvWithDefault("EXTERNAL_URL", "http://localhost"), "External URL for the proxy")
 	rootCmd.Flags().StringVarP(&proxyURL, "proxy-url", "p", getEnvWithDefault("PROXY_URL", "http://localhost:8080"), "Proxy URL for the proxy")
-	rootCmd.Flags().StringVarP(&globalSecret, "global-secret", "s", getEnvWithDefault("GLOBAL_SECRET", "supersecret"), "Global secret for the proxy")
 
 	// Google OAuth configuration
 	rootCmd.Flags().StringVar(&googleClientID, "google-client-id", getEnvWithDefault("GOOGLE_CLIENT_ID", ""), "Google OAuth client ID")

pkg/mcp-proxy/main.go

@@ -2,7 +2,6 @@ package mcpproxy
 
 import (
 	"context"
-	"crypto/sha256"
 	"errors"
 	"fmt"
 	"net/http"
@@ -37,7 +36,6 @@ func Run(
 	dataPath string,
 	externalURL string,
 	proxyURL string,
-	globalSecret string,
 	googleClientID string,
 	googleClientSecret string,
 	googleAllowedUsers []string,
@@ -54,8 +52,11 @@ func Run(
 	if parsedExternalURL.Path != "" {
 		return fmt.Errorf("external URL must not have a path, got: %s", parsedExternalURL.Path)
 	}
-	sha256Hash := sha256.Sum256([]byte(globalSecret))
-	secret := sha256Hash[:]
+
+	secret, err := utils.LoadOrGenerateSecret(path.Join(dataPath, "secret"))
+	if err != nil {
+		return fmt.Errorf("failed to load or generate secret: %w", err)
+	}
 
 	var config zap.Config
 	if os.Getenv("MODE") == "debug" {

pkg/utils/keys.go

@@ -9,6 +9,30 @@ import (
 	"os"
 )
 
+const SecretSize = 32
+
+func LoadOrGenerateSecret(secretPath string) ([]byte, error) {
+	_, err := os.Stat(secretPath)
+	if os.IsNotExist(err) {
+		secret := make([]byte, SecretSize)
+		if _, err := rand.Read(secret); err != nil {
+			return nil, fmt.Errorf("failed to generate secret: %w", err)
+		}
+		if err := os.WriteFile(secretPath, secret, 0600); err != nil {
+			return nil, fmt.Errorf("failed to save secret: %w", err)
+		}
+		return secret, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("failed to stat secret file: %w", err)
+	}
+	secret, err := os.ReadFile(secretPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read secret file: %w", err)
+	}
+	return secret, nil
+}
+
 func LoadOrGeneratePrivateKey(keyPath string) (*rsa.PrivateKey, error) {
 	_, err := os.Stat(keyPath)
 	if os.IsNotExist(err) {