vane 0.9.2

/* integration/pkg/env/certs.go */
package env

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"fmt"
	"math/big"
	"os"
	"path/filepath"
	"time"
)

// GenerateCertFile writes a self-signed certificate and key to the sandbox's certs directory.
// name: "default" -> creates default.crt and default.key
func (s *Sandbox) GenerateCertFile(name string, dnsName string) error {
	certPEM, keyPEM, err := generatePEM(dnsName)
	if err != nil {
		return err
	}

	certPath := filepath.Join(s.ConfigDir, "certs", fmt.Sprintf("%s.crt", name))
	keyPath := filepath.Join(s.ConfigDir, "certs", fmt.Sprintf("%s.key", name))

	if err := os.WriteFile(certPath, certPEM, 0644); err != nil {
		return fmt.Errorf("failed to write cert: %w", err)
	}
	if err := os.WriteFile(keyPath, keyPEM, 0600); err != nil {
		return fmt.Errorf("failed to write key: %w", err)
	}

	return nil
}

func generatePEM(dnsName string) ([]byte, []byte, error) {
	key, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		return nil, nil, err
	}

	// Use a large random serial number
	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
	if err != nil {
		return nil, nil, err
	}

	template := x509.Certificate{
		SerialNumber: serialNumber,
		Subject: pkix.Name{
			Organization: []string{"Vane Test Sandbox"},
			CommonName:   dnsName,
		},
		NotBefore:             time.Now().Add(-1 * time.Hour),
		NotAfter:              time.Now().Add(24 * time.Hour),
		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
		BasicConstraintsValid: true,
		DNSNames:              []string{dnsName},
	}

	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &key.PublicKey, key)
	if err != nil {
		return nil, nil, err
	}

	certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
	keyPEM := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key)})

	return certPEM, keyPEM, nil
}