stackrox · juanrh · Feb 8, 2022 · Jan 28, 2022 · Jan 28, 2022 · Jan 28, 2022
@@ -0,0 +1,65 @@
+package localscanner
+
+import (
+	"crypto/x509"
+	"math/rand"
+	"time"
+
+	"github.com/cloudflare/cfssl/helpers"
+	"github.com/pkg/errors"
+	"github.com/stackrox/rox/generated/storage"
+)
+
+var (
+	// ErrEmptyCertificate indicates that the certificate stored in a secret is empty.
+	ErrEmptyCertificate = errors.New("empty certificate")
+)
+
+// GetCertsRenewalTime computes the time when the service certificates should be refreshed.
+// If different services have different expiration times then the earliest time is returned.
+func GetCertsRenewalTime(certificates *storage.TypedServiceCertificateSet) (time.Time, error) {
+	var (
+		renewalTime            time.Time
+		renewalTimeInitialized bool
+	)
+	for _, certificate := range certificates.GetServiceCerts() {
+		certRenewalTime, err := getCertificateRenewalTime(certificate)
+		if err != nil {
+			return renewalTime, err
+		}
+		if !renewalTimeInitialized || certRenewalTime.Before(renewalTime) {
+			renewalTimeInitialized = true
+			renewalTime = certRenewalTime
+		}
+	}
+	return renewalTime, nil
+}
+
+func getCertificateRenewalTime(certificate *storage.TypedServiceCertificate) (time.Time, error) {
+	certBytes := certificate.GetCert().GetCertPem()
+	var (
+		cert *x509.Certificate
+		err  error
+	)
+	if len(certBytes) == 0 {
+		err = ErrEmptyCertificate
+	} else {
+		cert, err = helpers.ParseCertificatePEM(certBytes)
+	}
+	if err != nil {
+		var zeroTime time.Time
+		return zeroTime, err
+	}
+
+	return calculateRenewalTime(cert), nil
+}
+
+// In order to ensure certificates are rotated before expiration, this returns a renewal time no later than
+// half its expiration date.
+func calculateRenewalTime(cert *x509.Certificate) time.Time {
+	certValidityDurationSecs := cert.NotAfter.Sub(cert.NotBefore).Seconds()
+	durationBeforeRenewalAttempt := time.Second *
+		(time.Duration(certValidityDurationSecs/2) - time.Duration(rand.Intn(int(certValidityDurationSecs/10))))
+	certRenewalTime := cert.NotBefore.Add(durationBeforeRenewalAttempt)
+	return certRenewalTime
+}
@@ -0,0 +1,82 @@
+package localscanner
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stackrox/rox/generated/storage"
+	"github.com/stackrox/rox/pkg/mtls"
+	testutilsMTLS "github.com/stackrox/rox/pkg/mtls/testutils"
+	"github.com/stackrox/rox/pkg/testutils/envisolator"
+	"github.com/stretchr/testify/suite"
+)
+
+var (
+	// should be the same as the expiration corresponding to `mtls.WithValidityExpiringInHours()`.
+	afterOffset = 3 * time.Hour
+)
+
+func TestGetSecretRenewalTime(t *testing.T) {
+	suite.Run(t, new(getSecretRenewalTimeSuite))
+}
+
+type getSecretRenewalTimeSuite struct {
+	suite.Suite
+	envIsolator *envisolator.EnvIsolator
+}
+
+func (s *getSecretRenewalTimeSuite) SetupSuite() {
+	s.envIsolator = envisolator.NewEnvIsolator(s.T())
+}
+
+func (s *getSecretRenewalTimeSuite) SetupTest() {
+	err := testutilsMTLS.LoadTestMTLSCerts(s.envIsolator)
+	s.Require().NoError(err)
+}
+
+func (s *getSecretRenewalTimeSuite) TearDownTest() {
+	s.envIsolator.RestoreAll()
+}
+
+func (s *getSecretRenewalTimeSuite) TestGetSecretsCertRenewalTime() {
+	certPEMHours, err := issueCertificatePEM(mtls.WithValidityExpiringInHours())
+	s.Require().NoError(err)
+	certPEMDays, err := issueCertificatePEM(mtls.WithValidityExpiringInDays())
+	s.Require().NoError(err)
+	certificates := &storage.TypedServiceCertificateSet{
+		CaPem: make([]byte, 0),
+		ServiceCerts: []*storage.TypedServiceCertificate{
+			{
+				ServiceType: storage.ServiceType_SCANNER_SERVICE,
+				Cert: &storage.ServiceCertificate{
+					CertPem: certPEMHours,
+				},
+			},
+			{
+				ServiceType: storage.ServiceType_SCANNER_DB_SERVICE,
+				Cert: &storage.ServiceCertificate{
+					CertPem: certPEMDays,
+				},
+			},
+		},
+	}
+
+	certRenewalTime, err := GetCertsRenewalTime(certificates)
+
+	s.Require().NoError(err)
+	certDuration := time.Until(certRenewalTime)
+	s.LessOrEqual(certDuration, afterOffset/2)
+}
+
+func issueCertificatePEM(issueOption mtls.IssueCertOption) ([]byte, error) {
+	ca, err := mtls.CAForSigning()
+	if err != nil {
+		return nil, err
+	}
+	subject := mtls.NewSubject("clusterId", storage.ServiceType_SCANNER_SERVICE)
+	cert, err := ca.IssueCertForSubject(subject, issueOption)
+	if err != nil {
+		return nil, err
+	}
+	return cert.CertPEM, err
+}