Golang技术在微服务架构中实现安全性？

// auth.go
package auth

import (
    "context"
    "encoding/base64"
    "fmt"
    "log"
    "net/http"

    "crypto/sha256"
    "crypto/subtle"
)

// Middleware for authentication
func Middleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        // Get the authorization header
        authHeader := r.Header.Get("Authorization")

        // Parse the authorization header
        if authHeader == "" || !strings.HasPrefix(authHeader, "Basic ") {
            http.Error(w, "Unauthorized", http.StatusUnauthorized)
            return
        }

        // Decode the base64 encoded credentials
        credentials, err := base64.StdEncoding.DecodeString(authHeader[6:])
        if err != nil {
            http.Error(w, "Unauthorized", http.StatusUnauthorized)
            return
        }

        // Split the credentials into username and password
        username, password, ok := strings.Cut(string(credentials), ":")
        if !ok {
            http.Error(w, "Unauthorized", http.StatusUnauthorized)
            return
        }

        // Verify the credentials
        if verifyCredentials(username, password) {
            // Set the authenticated user in the context
            ctx := context.WithValue(r.Context(), "user", username)

            // Call the next handler with the authenticated context
            next.ServeHTTP(w, r.WithContext(ctx))
        } else {
            http.Error(w, "Unauthorized", http.StatusUnauthorized)
            return
        }
    })
}

// Function to verify credentials
func verifyCredentials(username, password string) bool {
    // Hash the password using SHA-256
    passwordHash := sha256.Sum256([]byte(password))

    // Compare the hashed password with the stored password
    return subtle.ConstantTimeCompare(passwordHash[:], []byte("storedPasswordHash")) == 1
}