# Missing Authentication for Critical Function (CWE-306)

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

**Stack:** Go

- Prevalence: Hoch Häufig ausgenutzt
- Impact: Hoch 6 Regeln mit hohem Schweregrad
- Prevention: Dokumentiert 6 Fix-Beispiele

**OWASP:** Identification and Authentication Failures (A07:2021-Identification and Authentication Failures) - #7

## Description

As data traverses trust boundaries, the data should be validated before being processed. When authentication is not applied to critical functions, attackers can invoke these functions without proving their identity.

## Prevention

### Go

Add Echo JWT middleware to protect API endpoints

Add Fiber JWT middleware to protect API endpoints

Add JWT authentication middleware to protect API endpoints

## Warning Signs

- [HIGH] Gin application missing JWT authentication middleware

## Consequences

- Privilegien erlangen
- Anwendungsdaten lesen
- Anwendungsdaten ändern
- Nicht autorisierten Code ausführen

## Mitigations

- Software in Komponenten mit unterschiedlichen Vertrauensstufen aufteilen
- Alle Bereiche mit sicherheitskritischer Funktionalität identifizieren und Authentifizierung für sie alle vorschreiben
- Sicherstellen, dass angemessene Zugriffskontrollen durchgesetzt werden

## Detection

- Total rules: 6
- Languages: python, go, typescript

## Rules by Language

### Go (3 rules)

- **Echo Missing JWT Middleware** [HIGH]: API endpoints lack JWT authentication middleware protection.
  - Remediation: Add JWT middleware to protect API routes.

```go
import "github.com/labstack/echo-jwt/v4"

api := e.Group("/api")
api.Use(echojwt.JWT([]byte(os.Getenv("JWT_SECRET"))))
api.POST("/transfer", transferHandler)
```

Learn more: https://shoulder.dev/learn/go/cwe-306/jwt-middleware
- **Fiber Missing JWT Middleware** [HIGH]: API endpoints lack JWT authentication middleware protection.
  - Remediation: Add JWT middleware to protect API routes.

```go
import "github.com/gofiber/contrib/jwt"

api := app.Group("/api")
api.Use(jwtware.New(jwtware.Config{
    SigningKey: jwtware.SigningKey{Key: []byte(os.Getenv("JWT_SECRET"))},
}))
api.Post("/transfer", transferHandler)
```

Learn more: https://shoulder.dev/learn/go/cwe-306/jwt-middleware
- **Gin Missing JWT Middleware** [HIGH]: API endpoints lack JWT authentication middleware protection.
  - Remediation: Add JWT middleware to protect API routes.

```go
import jwt "github.com/appleboy/gin-jwt/v2"

auth, _ := jwt.New(&jwt.GinJWTMiddleware{
    Realm: "api",
    Key:   []byte(os.Getenv("JWT_SECRET")),
})
api := r.Group("/api")
api.Use(auth.MiddlewareFunc())
api.POST("/transfer", transferHandler)
```

Learn more: https://shoulder.dev/learn/go/cwe-306/jwt-middleware