Phishing Api Keys in Echo Go

Phishing API keys in Echo Go typically occurs when Echo Go applications inadvertently expose sensitive credentials through their built-in HTTP handlers or when malicious actors create deceptive endpoints that mimic legitimate Echo Go API routes. The Echo Go framework's minimalist approach to routing and middleware can create blind spots where API keys are logged in plain text or returned in error responses.

A common vulnerability pattern in Echo Go involves the default logging middleware capturing request headers containing API keys. Consider this problematic pattern:

func main() {
    e := echo.New()
    
    // Default logging captures ALL headers including Authorization
    e.Use(middleware.Logger())
    
    e.POST("/api/verify", func(c echo.Context) error {
        key := c.Request().Header.Get("Authorization")
        // Process API key
        return c.JSON(http.StatusOK, map[string]string{"status": "verified"})
    })
    
    e.Start(":8080")
}

This code logs the Authorization header to stdout or a log file, creating a persistent record of API keys that could be accessed by unauthorized parties. Attackers can exploit this by sending requests to the endpoint and monitoring log files, or by creating phishing endpoints that appear legitimate to Echo Go developers.

Another Echo Go-specific manifestation involves the framework's flexible parameter binding. When using c.Bind() without proper validation, API keys can be inadvertently exposed through JSON responses or error messages:

type LoginRequest struct {
    APIKey string `json:"api_key"`
}

func login(c echo.Context) error {
    var req LoginRequest
    if err := c.Bind(&req); err != nil {
        // Error response may include the raw request body
        return c.JSON(http.StatusBadRequest, map[string]interface{}{
            "error": err.Error(),
            "received": req, // API key exposed here
        })
    }
    
    // Validate API key
    if !validateAPIKey(req.APIKey) {
        return c.JSON(http.StatusUnauthorized, map[string]string{
            "error": "Invalid API key",
            "key_provided": req.APIKey, // Key exposed in response
        })
    }
    
    return c.JSON(http.StatusOK, map[string]string{"token": "valid"})
}

The Echo Go framework's default behavior of including request data in error responses can inadvertently leak API keys to clients, especially when combined with inadequate error handling. This becomes particularly dangerous in development environments where detailed error messages are enabled by default.

Detecting phishing API key vulnerabilities in Echo Go applications requires both static analysis of the codebase and dynamic runtime scanning. middleBrick's black-box scanning approach is particularly effective for Echo Go applications since it can identify exposed API key patterns without requiring access to source code.

For Echo Go applications, middleBrick's scanning process identifies several key indicators of phishing API key vulnerabilities:

Log File Analysis: middleBrick scans for Echo Go's default log output patterns that may contain API keys. The scanner looks for log entries containing Authorization headers, API key patterns (32-64 character alphanumeric strings, UUIDs, or JWT tokens), and Echo Go's default log format.

Response Analysis: The scanner examines API responses for Echo Go applications to detect whether API keys are being reflected back in error messages or validation responses. middleBrick's Inventory Management check specifically targets Echo Go's parameter binding patterns to identify where API keys might be exposed.

Endpoint Enumeration: middleBrick's black-box scanning discovers all Echo Go endpoints, including those that might not be documented in OpenAPI specifications. This is crucial because Echo Go's flexible routing can create endpoints that developers forget to secure.

Here's how you would scan an Echo Go API using middleBrick's CLI:

npm install -g middlebrick
middlebrick scan https://api.example.com --output json --format table

The scan results will include a security score and specific findings related to API key exposure. For Echo Go applications, middleBrick's LLM/AI Security checks also examine whether the Echo Go application is inadvertently exposing system prompts or AI model configurations that could be exploited.

middleBrick's OpenAPI analysis is particularly valuable for Echo Go applications since it can detect discrepancies between the documented API surface and the actual runtime behavior. This helps identify endpoints that might be vulnerable to API key phishing but aren't properly documented or secured.

Remediating phishing API key vulnerabilities in Echo Go requires implementing proper key handling patterns and leveraging Echo Go's middleware system. The key principle is to ensure API keys never appear in logs, error responses, or any client-facing output.

Secure Logging Middleware: Replace Echo Go's default logger with a custom middleware that redacts sensitive headers:

func secureLogger() echo.MiddlewareFunc {
    return func(next echo.HandlerFunc) echo.HandlerFunc {
        return func(c echo.Context) error {
            // Create a copy of headers without sensitive data
            headers := make(map[string]string)
            for k, v := range c.Request().Header {
                if k == "Authorization" || k == "Api-Key" {
                    headers[k] = "REDACTED"
                } else {
                    headers[k] = strings.Join(v, ", ")
                }
            }
            
            // Log with redacted headers
            log.Printf("Request: %s %s Headers: %v", 
                c.Request().Method, c.Request().URL.Path, headers)
            
            return next(c)
        }
    }
}

func main() {
    e := echo.New()
    e.Use(secureLogger())
    
    e.POST("/api/verify", func(c echo.Context) error {
        key := c.Request().Header.Get("Authorization")
        // Process API key securely
        return c.JSON(http.StatusOK, map[string]string{"status": "verified"})
    })
    
    e.Start(":8080")
}

Input Validation and Error Handling: Implement strict input validation and never include raw API keys in error responses:

type LoginRequest struct {
    APIKey string `json:"api_key" validate:"required"`
}

func login(c echo.Context) error {
    var req LoginRequest
    if err := c.Bind(&req); err != nil {
        return c.JSON(http.StatusBadRequest, map[string]string{
            "error": "Invalid request format",
        })
    }
    
    if !validateAPIKey(req.APIKey) {
        return c.JSON(http.StatusUnauthorized, map[string]string{
            "error": "Invalid API key",
        })
    }
    
    return c.JSON(http.StatusOK, map[string]string{"token": "valid"})
}

Echo Go-Specific Security Middleware: Create middleware that validates and sanitizes API key handling across all endpoints:

func apiSecurityMiddleware() echo.MiddlewareFunc {
    return func(next echo.HandlerFunc) echo.HandlerFunc {
        return func(c echo.Context) error {
            // Validate API key format before processing
            authHeader := c.Request().Header.Get("Authorization")
            if authHeader != "" && !isValidAPIKeyFormat(authHeader) {
                return c.JSON(http.StatusBadRequest, map[string]string{
                    "error": "Malformed API key",
                })
            }
            
            // Set a context value for the key without exposing it
            c.Set("apiKeyHash", hashAPIKey(authHeader))
            
            return next(c)
        }
    }
}

func main() {
    e := echo.New()
    e.Use(apiSecurityMiddleware())
    
    e.POST("/api/secure", func(c echo.Context) error {
        // Retrieve hashed key, never the raw value
        keyHash := c.Get("apiKeyHash")
        
        // Process request using the hashed key
        return c.JSON(http.StatusOK, map[string]string{"status": "processed"})
    })
    
    e.Start(":8080")
}

Continuous Monitoring with middleBrick: Integrate middleBrick's Pro plan into your Echo Go development workflow to continuously scan your API endpoints. The CI/CD integration can automatically fail builds if new phishing vulnerabilities are detected:

# .github/workflows/security.yml
name: API Security Scan
on: [push, pull_request]

jobs:
  security-scan:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    - name: Run middleBrick Scan
      run: |
        npm install -g middlebrick
        middlebrick scan https://staging-api.example.com --threshold B --fail-on-worse
      continue-on-error: false

This approach ensures that any Echo Go-specific API key phishing vulnerabilities are caught before deployment, maintaining the security integrity of your API endpoints.