Add provisioner option to disable renewal.

Fixes smallstep/ca-component#108

Author: maraino

authority/authority_test.go

@@ -15,6 +15,7 @@ func testAuthority(t *testing.T) *Authority {
 	assert.FatalError(t, err)
 	clijwk, err := stepJOSE.ParseKey("testdata/secrets/step_cli_key_pub.jwk")
 	assert.FatalError(t, err)
+	disableRenewal := true
 	p := []*Provisioner{
 		{
 			Name: "Max",
@@ -26,6 +27,14 @@ func testAuthority(t *testing.T) *Authority {
 			Type: "JWK",
 			Key:  clijwk,
 		},
+		{
+			Name: "dev",
+			Type: "JWK",
+			Key:  maxjwk,
+			Claims: &ProvisionerClaims{
+				DisableRenewal: &disableRenewal,
+			},
+		},
 	}
 	c := &Config{
 		Address:          "127.0.0.1:443",

authority/authorize.go

@@ -1,6 +1,8 @@
 package authority
 
 import (
+	"crypto/x509"
+	"encoding/asn1"
 	"net/http"
 	"time"
 
@@ -117,3 +119,54 @@ func (a *Authority) Authorize(ott string) ([]interface{}, error) {
 
 	return signOps, nil
 }
+
+// authorizeRenewal tries to locate the step provisioner extension, and checks
+// if for the configured provisioner, the renewal is enabled or not. If the
+// extra extension cannot be found, authorize the renewal by default.
+//
+// TODO(mariano): should we authorize by default?
+func (a *Authority) authorizeRenewal(crt *x509.Certificate) error {
+	errContext := map[string]interface{}{"serialNumber": crt.SerialNumber.String()}
+	for _, e := range crt.Extensions {
+		if e.Id.Equal(stepOIDProvisioner) {
+			var provisioner stepProvisionerASN1
+			if _, err := asn1.Unmarshal(e.Value, &provisioner); err != nil {
+				return &apiError{
+					err:     errors.Wrap(err, "error decoding step provisioner extension"),
+					code:    http.StatusInternalServerError,
+					context: errContext,
+				}
+			}
+
+			// Look for the provisioner, if it cannot be found, renewal will not
+			// be authorized.
+			pid := string(provisioner.Name) + ":" + string(provisioner.CredentialID)
+			val, ok := a.provisionerIDIndex.Load(pid)
+			if !ok {
+				return &apiError{
+					err:     errors.Errorf("not found: provisioner %s", pid),
+					code:    http.StatusUnauthorized,
+					context: errContext,
+				}
+			}
+			p, ok := val.(*Provisioner)
+			if !ok {
+				return &apiError{
+					err:     errors.Errorf("invalid type: provisioner %s, type %T", pid, val),
+					code:    http.StatusInternalServerError,
+					context: errContext,
+				}
+			}
+			if p.Claims.IsDisableRenewal() {
+				return &apiError{
+					err:     errors.Errorf("renew disabled: provisioner %s", pid),
+					code:    http.StatusUnauthorized,
+					context: errContext,
+				}
+			}
+			return nil
+		}
+	}
+
+	return nil
+}

authority/config.go

@@ -23,10 +23,12 @@ var (
 		MaxVersion:    1.2,
 		Renegotiation: false,
 	}
+	defaultDisableRenewal   = false
 	globalProvisionerClaims = ProvisionerClaims{
-		MinTLSDur:     &duration{5 * time.Minute},
-		MaxTLSDur:     &duration{24 * time.Hour},
-		DefaultTLSDur: &duration{24 * time.Hour},
+		MinTLSDur:      &duration{5 * time.Minute},
+		MaxTLSDur:      &duration{24 * time.Hour},
+		DefaultTLSDur:  &duration{24 * time.Hour},
+		DisableRenewal: &defaultDisableRenewal,
 	}
 )
 

authority/provisioner.go

@@ -11,10 +11,11 @@ import (
 
 // ProvisionerClaims so that individual provisioners can override global claims.
 type ProvisionerClaims struct {
-	globalClaims  *ProvisionerClaims
-	MinTLSDur     *duration `json:"minTLSCertDuration,omitempty"`
-	MaxTLSDur     *duration `json:"maxTLSCertDuration,omitempty"`
-	DefaultTLSDur *duration `json:"defaultTLSCertDuration,omitempty"`
+	globalClaims   *ProvisionerClaims
+	MinTLSDur      *duration `json:"minTLSCertDuration,omitempty"`
+	MaxTLSDur      *duration `json:"maxTLSCertDuration,omitempty"`
+	DefaultTLSDur  *duration `json:"defaultTLSCertDuration,omitempty"`
+	DisableRenewal *bool     `json:"disableRenewal,omitempty"`
 }
 
 // Init initializes and validates the individual provisioner claims.
@@ -57,6 +58,16 @@ func (pc *ProvisionerClaims) MaxTLSCertDuration() time.Duration {
 	return pc.MaxTLSDur.Duration
 }
 
+// IsDisableRenewal returns if the renewal flow is disabled for the
+// provisioner. If the property is not set withing the provisioner, then the
+// global value from the authority configuration will be used.
+func (pc *ProvisionerClaims) IsDisableRenewal() bool {
+	if pc.DisableRenewal == nil {
+		return pc.globalClaims.IsDisableRenewal()
+	}
+	return *pc.DisableRenewal
+}
+
 // Validate validates and modifies the Claims with default values.
 func (pc *ProvisionerClaims) Validate() error {
 	var (

authority/tls.go

@@ -169,6 +169,12 @@ func (a *Authority) Sign(csr *x509.CertificateRequest, signOpts SignOptions, ext
 // Renew creates a new Certificate identical to the old certificate, except
 // with a validity window that begins 'now'.
 func (a *Authority) Renew(ocx *x509.Certificate) (*x509.Certificate, *x509.Certificate, error) {
+	// Check step provisioner extensions
+	if err := a.authorizeRenewal(ocx); err != nil {
+		return nil, nil, err
+	}
+
+	// Issuer
 	issIdentity := a.intermediateIdentity
 
 	// Convert a realx509.Certificate to the step x509 Certificate.

authority/tls_test.go

@@ -251,6 +251,19 @@ func TestRenew(t *testing.T) {
 	crt, err := x509.ParseCertificate(crtBytes)
 	assert.FatalError(t, err)
 
+	leafNoRenew, err := x509util.NewLeafProfile("norenew", a.intermediateIdentity.Crt,
+		a.intermediateIdentity.Key,
+		x509util.WithNotBeforeAfterDuration(so.NotBefore, so.NotAfter, 0),
+		withDefaultASN1DN(a.config.AuthorityConfig.Template),
+		x509util.WithPublicKey(pub), x509util.WithHosts("test.smallstep.com,test"),
+		withProvisionerOID("dev", a.config.AuthorityConfig.Provisioners[2].Key.KeyID),
+	)
+	assert.FatalError(t, err)
+	crtBytesNoRenew, err := leafNoRenew.CreateCertificate()
+	assert.FatalError(t, err)
+	crtNoRenew, err := x509.ParseCertificate(crtBytesNoRenew)
+	assert.FatalError(t, err)
+
 	type renewTest struct {
 		auth *Authority
 		crt  *x509.Certificate
@@ -274,6 +287,16 @@ func TestRenew(t *testing.T) {
 					http.StatusInternalServerError, context{}},
 			}, nil
 		},
+		"fail-unauthorized": func() (*renewTest, error) {
+			ctx := map[string]interface{}{
+				"serialNumber": crtNoRenew.SerialNumber.String(),
+			}
+			return &renewTest{
+				crt: crtNoRenew,
+				err: &apiError{errors.New("renew disabled"),
+					http.StatusUnauthorized, ctx},
+			}, nil
+		},
 		"success": func() (*renewTest, error) {
 			return &renewTest{
 				crt: crt,