TBD: command to rotate device CAs

Signed-off-by: Volodymyr Khoroz <[email protected]>

subcommands/keys/ca_renewal_resign_device_ca.go

@@ -0,0 +1,66 @@
+package keys
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+
+	//"github.com/foundriesio/fioctl/client"
+	"github.com/foundriesio/fioctl/subcommands"
+	"github.com/foundriesio/fioctl/x509"
+)
+
+func init() {
+	cmd := &cobra.Command{
+		Use:   "re-sign-device-ca <PKI Directory> [<Old PKI Directory>]",
+		Short: "Re-sign all existing Device CAs with a new root CA for your Factory PKI",
+		Run:   doReSignDeviceCaRenewal,
+		Args:  cobra.RangeArgs(1, 2),
+		Long: `Re-sign all existing Device CAs with a new root CA for your Factory PKI.
+
+Both currently active and disabled Device CAs are being re-signed.
+All their properties are preserved, including a serial number.
+Only the signature and authority key ID are being changed.
+This allows old certificates (issued by a previous root CA) to continue being used to issue device client certificates.
+
+Re-signed device CA certificates are stored in the provided PKI directory.
+An old PKI directory is used to locate corresponding private keys, and copy them into the PKI directory.
+Each located device CA gets the same file name, as it was in the old PKI directory.
+If a device CA certificate cannot be located in an old PKI directory - it does not get stored locally.
+If an old PKI directory argument is not provided, new certificates are not stored locally.
+`,
+	}
+	caRenewalCmd.AddCommand(cmd)
+	cmd.Flags().StringVarP(&hsmModule, "hsm-module", "", "", "Load a root CA key from a PKCS#11 compatible HSM using this module")
+	cmd.Flags().StringVarP(&hsmPin, "hsm-pin", "", "", "The PKCS#11 PIN to log into the HSM")
+	cmd.Flags().StringVarP(&hsmTokenLabel, "hsm-token-label", "", "", "The label of the HSM token holding the root CA key")
+}
+
+func doReSignDeviceCaRenewal(cmd *cobra.Command, args []string) {
+	factory := viper.GetString("factory")
+	certsDir := args[0]
+	oldCertsDir := args[1]
+	subcommands.DieNotNil(os.Chdir(certsDir))
+	hsm, err := x509.ValidateHsmArgs(
+		hsmModule, hsmPin, hsmTokenLabel, "--hsm-module", "--hsm-pin", "--hsm-token-label")
+	subcommands.DieNotNil(err)
+	x509.InitHsm(hsm)
+
+	// TBD: load serial-to-filename map from oldCertsDir
+	// TBD: fetch current device CAs from the server, re-sign them, store locally (if matched), and upload back.
+	// TBD - linter
+	fmt.Println(factory, oldCertsDir)
+}
+
+// TBD: commands to add:
+// # Re-sign existing TLS certs. As we don't care for their serial numbers - it is an alias to "fioctl keys rotate-tls".
+// - fioctl keys renewal re-sign-tls <PKI Directory>
+// # Revoke a specific root CA by its serial number. Cannot revoke currently active root CA.
+// # This also revokes the cross-signed renewal bundle root CAs, associated with this root CA.
+// - fioctl keys renewal revoke-root <PKI Directory> --serial
+
+// There will be no such command as `fioctl keys renewal finish`.
+// Otherwise, users would often abuse it, leading to devices losing connectivity.
+// Having harder to grasp command names, like e.g. revoke-root makes this process more controlled.

x509/bash.go

@@ -7,6 +7,7 @@ package x509
 
 import (
 	"crypto"
+	"crypto/x509"
 	"os"
 	"os/exec"
 
@@ -164,6 +165,10 @@ func SignEl2GoCsr(csrPem string) string {
 	return signCaCsr("el2g-*", csrPem)
 }
 
+func ReSignCrt(crt *x509.Certificate) string {
+	return neverland()
+}
+
 func CreateCrl(serials map[string]int) string {
 	return neverland()
 }

x509/golang.go

@@ -34,6 +34,7 @@ func CreateFactoryCrossCa(ou string, pubkey crypto.PublicKey) string {
 	// This function does an inverse: produces a factory CA with a public key "borrowed" from another factory CA.
 	// The end result is the same, but we don't need to export the internal key storage interface.
 	// This certificate is not written to disk, as it is only needed intermittently.
+	// Cannot use a ReSignCrt as we need a new certificate here (with e.g. a new serial number).
 	priv := factoryCaKeyStorage.loadKey()
 	crtTemplate := genFactoryCaTemplate(marshalSubject(factoryCaName, ou))
 	return genCertificate(crtTemplate, crtTemplate, pubkey, priv)
@@ -74,6 +75,13 @@ func SignEstCsr(csrPem string) string {
 	return genTlsCert(csr.Subject, csr.DNSNames, csr.PublicKey)
 }
 
+func ReSignCrt(crt *x509.Certificate) string {
+	// Use an input certificate as a template for a new certificate, preserving all its properties except a signature.
+	factoryKey := factoryCaKeyStorage.loadKey()
+	factoryCa := LoadCertFromFile(FactoryCaCertFile)
+	return genCertificate(crt, factoryCa, crt.PublicKey, factoryKey)
+}
+
 var oidExtensionReasonCode = []int{2, 5, 29, 21}
 
 func CreateCrl(serials map[string]int) string {