Mengonfigurasi sertifikat SSL untuk koneksi TCP menggunakan Go

Mengonfigurasi sertifikat SSL (Secure Sockets Layer) untuk koneksi TCP ke Cloud SQL untuk MySQL menggunakan paket database/sql Go.

Contoh kode

Go

Untuk melakukan autentikasi ke Cloud SQL untuk MySQL, siapkan Kredensial Default Aplikasi. Untuk mengetahui informasi selengkapnya, baca Menyiapkan autentikasi untuk lingkungan pengembangan lokal.

package cloudsql

import (
	"crypto/tls"
	"crypto/x509"
	"database/sql"
	"errors"
	"fmt"
	"log"
	"os"

	"github.com/go-sql-driver/mysql"
)

// connectTCPSocket initializes a TCP connection pool for a Cloud SQL
// instance of MySQL.
func connectTCPSocket() (*sql.DB, error) {
	mustGetenv := func(k string) string {
		v := os.Getenv(k)
		if v == "" {
			log.Fatalf("Fatal Error in connect_tcp.go: %s environment variable not set.", k)
		}
		return v
	}
	// Note: Saving credentials in environment variables is convenient, but not
	// secure - consider a more secure solution such as
	// Cloud Secret Manager (https://cloud.google.com/secret-manager) to help
	// keep secrets safe.
	var (
		dbUser    = mustGetenv("DB_USER")       // e.g. 'my-db-user'
		dbPwd     = mustGetenv("DB_PASS")       // e.g. 'my-db-password'
		dbName    = mustGetenv("DB_NAME")       // e.g. 'my-database'
		dbPort    = mustGetenv("DB_PORT")       // e.g. '3306'
		dbTCPHost = mustGetenv("INSTANCE_HOST") // e.g. '127.0.0.1' ('172.17.0.1' if deployed to GAE Flex)
	)

	dbURI := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?parseTime=true",
		dbUser, dbPwd, dbTCPHost, dbPort, dbName)

	// (OPTIONAL) Configure SSL certificates
	// For deployments that connect directly to a Cloud SQL instance without
	// using the Cloud SQL Proxy, configuring SSL certificates will ensure the
	// connection is encrypted.
	if dbRootCert, ok := os.LookupEnv("DB_ROOT_CERT"); ok { // e.g., '/path/to/my/server-ca.pem'
		var (
			dbCert = mustGetenv("DB_CERT") // e.g. '/path/to/my/client-cert.pem'
			dbKey  = mustGetenv("DB_KEY")  // e.g. '/path/to/my/client-key.pem'
		)
		pool := x509.NewCertPool()
		pem, err := os.ReadFile(dbRootCert)
		if err != nil {
			return nil, err
		}
		if ok := pool.AppendCertsFromPEM(pem); !ok {
			return nil, errors.New("unable to append root cert to pool")
		}
		cert, err := tls.LoadX509KeyPair(dbCert, dbKey)
		if err != nil {
			return nil, err
		}
		mysql.RegisterTLSConfig("cloudsql", &tls.Config{
			RootCAs:      pool,
			Certificates: []tls.Certificate{cert},
			// InsecureSkipVerify and a custom VerifyPeerCertificate function is
			// required to handle Cloud SQL's custom certificates.
			// As an alternative it's also possible to inspect the server
			// certificate and extract the SAN field and use that a ServerName
			// while removing InsecureSkipVerify and VerifyPeerCertificate.
			InsecureSkipVerify:    true,
			VerifyPeerCertificate: verifyPeerCertFunc(pool),
		})
		dbURI += "&tls=cloudsql"
	}

	// dbPool is the pool of database connections.
	dbPool, err := sql.Open("mysql", dbURI)
	if err != nil {
		return nil, fmt.Errorf("sql.Open: %w", err)
	}

	// ...

	return dbPool, nil
}


// verifyPeerCertFunc returns a function that verifies the peer certificate is
// in the cert pool.
func verifyPeerCertFunc(pool *x509.CertPool) func([][]byte, [][]*x509.Certificate) error {
	return func(rawCerts [][]byte, _ [][]*x509.Certificate) error {
		if len(rawCerts) == 0 {
			return errors.New("no certificates available to verify")
		}

		cert, err := x509.ParseCertificate(rawCerts[0])
		if err != nil {
			return err
		}

		opts := x509.VerifyOptions{Roots: pool}
		if _, err = cert.Verify(opts); err != nil {
			return err
		}
		return nil
	}
}

Langkah selanjutnya

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