Changing minimum certificate rotation period and backdating to 1h

Signed-off-by: Diogo Monica <diogo.monica@gmail.com>

ca/certificates.go

@@ -57,19 +57,17 @@ const (
 	RootCAExpiration = "630720000s"
 	// DefaultNodeCertExpiration represents the default expiration for node certificates (3 months)
 	DefaultNodeCertExpiration = 2160 * time.Hour
+	// CertDefaultBackdate represents the amount of time each certificate is backdated to try to avoid
+	// clock drift issues.
+	CertDefaultBackdate = -1 * time.Hour
 	// CertLowerRotationRange represents the minimum fraction of time that we will wait when randomly
 	// choosing our next certificate rotation
 	CertLowerRotationRange = 0.5
 	// CertUpperRotationRange represents the maximum fraction of time that we will wait when randomly
 	// choosing our next certificate rotation
 	CertUpperRotationRange = 0.8
-	// MinNodeCertExpiration represents the minimum expiration for node certificates (25 + 5 minutes)
-	// X - 5 > CertUpperRotationRange * X <=> X < 5/(1 - CertUpperRotationRange)
-	// Since we're issuing certificates 5 minutes in the past to get around clock drifts, and
-	// we're selecting a random rotation distribution range from CertLowerRotationRange to
-	// CertUpperRotationRange, we need to ensure that we don't accept an expiration time that will
-	// make a node able to randomly choose the next rotation after the expiration of the certificate.
-	MinNodeCertExpiration = 30 * time.Minute
+	// MinNodeCertExpiration represents the minimum expiration for node certificates
+	MinNodeCertExpiration = 1 * time.Hour
 )
 
 // ErrNoLocalRootCA is an error type used to indicate that the local root CA

ca/certificates_test.go

@@ -534,12 +534,12 @@ func TestNewRootCANonDefaultExpiry(t *testing.T) {
 	parsedCerts, err := helpers.ParseCertificatesPEM(cert)
 	assert.NoError(t, err)
 	assert.Len(t, parsedCerts, 2)
-	assert.True(t, time.Now().Add(time.Minute*50).Before(parsedCerts[0].NotAfter))
-	assert.True(t, time.Now().Add(time.Hour).After(parsedCerts[0].NotAfter))
+	assert.True(t, time.Now().Add(time.Minute*59).Before(parsedCerts[0].NotAfter))
+	assert.True(t, time.Now().Add(time.Hour).Add(time.Minute).After(parsedCerts[0].NotAfter))
 
-	// Sign the same CSR again, this time with a 29 Minute expiration RootCA (under the 30 minute minimum).
+	// Sign the same CSR again, this time with a 59 Minute expiration RootCA (under the 60 minute minimum).
 	// This should use the default of 3 months
-	newRootCA, err = ca.NewRootCA(rootCA.Cert, rootCA.Key, 29*time.Minute)
+	newRootCA, err = ca.NewRootCA(rootCA.Cert, rootCA.Key, 59*time.Minute)
 	assert.NoError(t, err)
 
 	cert, err = newRootCA.ParseValidateAndSignCSR(csr, "CN", ca.ManagerRole, "ORG")

ca/config.go

@@ -124,10 +124,15 @@ func SigningPolicy(certExpiry time.Duration) *cfconfig.Signing {
 		certExpiry = DefaultNodeCertExpiration
 	}
 
+	notBefore := time.Now().Round(time.Minute).Add(CertDefaultBackdate).UTC()
+	notAfter := time.Now().Round(time.Minute).Add(certExpiry).UTC()
+
 	return &cfconfig.Signing{
 		Default: &cfconfig.SigningProfile{
-			Usage:  []string{"signing", "key encipherment", "server auth", "client auth"},
-			Expiry: certExpiry,
+			Usage:     []string{"signing", "key encipherment", "server auth", "client auth"},
+			Expiry:    certExpiry,
+			NotBefore: notBefore,
+			NotAfter:  notAfter,
 			// Only trust the key components from the CSR. Everything else should
 			// come directly from API call params.
 			CSRWhitelist: &cfconfig.CSRWhitelist{