# 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: Alta Frecuentemente explotada
- Impact: Alto 6 reglas de severidad alta
- Prevention: Documentada 6 ejemplos de corrección

**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

- Obtener privilegios
- Leer datos de la aplicación
- Modificar datos de la aplicación
- Ejecutar código no autorizado

## Mitigations

- Divide el software en componentes con distintos niveles de confianza
- Identifica todas las áreas con funcionalidad crítica para la seguridad y exige autenticación en todas ellas
- Asegura que se apliquen los controles de acceso apropiados

## 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