docs/signer/api/ecdsa_hardware_crypto_servi...

655 lines
18 KiB
Go

// +build pkcs11
package api
import (
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/sha256"
"crypto/x509"
"errors"
"fmt"
"io"
"math/big"
"github.com/Sirupsen/logrus"
"github.com/docker/notary/passphrase"
"github.com/docker/notary/trustmanager"
"github.com/docker/notary/tuf/data"
"github.com/miekg/pkcs11"
)
const (
USER_PIN = "123456"
SO_USER_PIN = "010203040506070801020304050607080102030405060708"
numSlots = 50 // number of slots in the yubikey
)
// Hardcoded yubikey PKCS11 ID
var YUBIKEY_ROOT_KEY_ID = []byte{2}
type yubiSlot struct {
role string
slotID []byte
}
// YubiPrivateKey represents a private key inside of a yubikey
type YubiPrivateKey struct {
data.ECDSAPublicKey
passRetriever passphrase.Retriever
slot []byte
}
type YubikeySigner struct {
YubiPrivateKey
}
func NewYubiPrivateKey(slot []byte, pubKey data.ECDSAPublicKey, passRetriever passphrase.Retriever) *YubiPrivateKey {
return &YubiPrivateKey{
ECDSAPublicKey: pubKey,
passRetriever: passRetriever,
slot: slot,
}
}
func (ys *YubikeySigner) Public() crypto.PublicKey {
publicKey, err := x509.ParsePKIXPublicKey(ys.YubiPrivateKey.Public())
if err != nil {
return nil
}
return publicKey
}
// CryptoSigner returns a crypto.Signer tha wraps the YubiPrivateKey. Needed for
// Certificate generation only
func (y *YubiPrivateKey) CryptoSigner() crypto.Signer {
return &YubikeySigner{YubiPrivateKey: *y}
}
// Private is not implemented in hardware keys
func (y *YubiPrivateKey) Private() []byte {
// We cannot return the private material from a Yubikey
// TODO(david): We probably want to return an error here
return nil
}
func (y YubiPrivateKey) SignatureAlgorithm() data.SigAlgorithm {
return data.ECDSASignature
}
func (y *YubiPrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) ([]byte, error) {
ctx, session, err := SetupHSMEnv(pkcs11Lib)
if err != nil {
return nil, err
}
defer cleanup(ctx, session)
sig, err := sign(ctx, session, y.slot, y.passRetriever, msg)
if err != nil {
return nil, fmt.Errorf("failed to sign using Yubikey: %v", err)
}
return sig, nil
}
// addECDSAKey adds a key to the yubikey
func addECDSAKey(ctx *pkcs11.Ctx, session pkcs11.SessionHandle, privKey data.PrivateKey, pkcs11KeyID []byte, passRetriever passphrase.Retriever, role string) error {
logrus.Debugf("Got into add key with key: %s\n", privKey.ID())
// TODO(diogo): Figure out CKU_SO with yubikey
err := login(ctx, session, passRetriever, pkcs11.CKU_SO, SO_USER_PIN)
if err != nil {
return err
}
defer ctx.Logout(session)
// Create an ecdsa.PrivateKey out of the private key bytes
ecdsaPrivKey, err := x509.ParseECPrivateKey(privKey.Private())
if err != nil {
return err
}
ecdsaPrivKeyD := ecdsaPrivKey.D.Bytes()
logrus.Debugf("Getting D bytes: %v\n", ecdsaPrivKeyD)
template, err := trustmanager.NewCertificate(role)
if err != nil {
return fmt.Errorf("failed to create the certificate template: %v", err)
}
certBytes, err := x509.CreateCertificate(rand.Reader, template, template, ecdsaPrivKey.Public(), ecdsaPrivKey)
if err != nil {
return fmt.Errorf("failed to create the certificate: %v", err)
}
certTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_CERTIFICATE),
pkcs11.NewAttribute(pkcs11.CKA_VALUE, certBytes),
pkcs11.NewAttribute(pkcs11.CKA_ID, pkcs11KeyID),
}
privateKeyTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_PRIVATE_KEY),
pkcs11.NewAttribute(pkcs11.CKA_KEY_TYPE, pkcs11.CKK_ECDSA),
pkcs11.NewAttribute(pkcs11.CKA_ID, pkcs11KeyID),
pkcs11.NewAttribute(pkcs11.CKA_EC_PARAMS, []byte{0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07}),
pkcs11.NewAttribute(pkcs11.CKA_VALUE, ecdsaPrivKeyD),
// 1 is touch enabled
// 2 is pin once
// 4 is pin always
pkcs11.NewAttribute(pkcs11.CKA_VENDOR_DEFINED, 3),
}
_, err = ctx.CreateObject(session, certTemplate)
if err != nil {
return fmt.Errorf("error importing: %v", err)
}
_, err = ctx.CreateObject(session, privateKeyTemplate)
if err != nil {
return fmt.Errorf("error importing: %v", err)
}
return nil
}
func getECDSAKey(ctx *pkcs11.Ctx, session pkcs11.SessionHandle, pkcs11KeyID []byte) (*data.ECDSAPublicKey, string, error) {
findTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_TOKEN, true),
pkcs11.NewAttribute(pkcs11.CKA_ID, pkcs11KeyID),
pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_PUBLIC_KEY),
}
attrTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_KEY_TYPE, []byte{0}),
pkcs11.NewAttribute(pkcs11.CKA_EC_POINT, []byte{0}),
pkcs11.NewAttribute(pkcs11.CKA_EC_PARAMS, []byte{0}),
}
if err := ctx.FindObjectsInit(session, findTemplate); err != nil {
logrus.Debugf("Failed to init: %s\n", err.Error())
return nil, "", err
}
obj, b, err := ctx.FindObjects(session, 1)
if err != nil {
logrus.Debugf("Failed to find: %s %v\n", err.Error(), b)
return nil, "", err
}
if err := ctx.FindObjectsFinal(session); err != nil {
logrus.Debugf("Failed to finalize: %s\n", err.Error())
return nil, "", err
}
if len(obj) != 1 {
logrus.Debugf("should have found one object")
return nil, "", errors.New("no matching keys found inside of yubikey")
}
// Retrieve the public-key material to be able to create a new HSMRSAKey
attr, err := ctx.GetAttributeValue(session, obj[0], attrTemplate)
if err != nil {
logrus.Debugf("Failed to get Attribute for: %v\n", obj[0])
return nil, "", err
}
// Iterate through all the attributes of this key and saves CKA_PUBLIC_EXPONENT and CKA_MODULUS. Removes ordering specific issues.
var rawPubKey []byte
for _, a := range attr {
if a.Type == pkcs11.CKA_EC_POINT {
rawPubKey = a.Value
}
}
ecdsaPubKey := ecdsa.PublicKey{Curve: elliptic.P256(), X: new(big.Int).SetBytes(rawPubKey[3:35]), Y: new(big.Int).SetBytes(rawPubKey[35:])}
pubBytes, err := x509.MarshalPKIXPublicKey(&ecdsaPubKey)
if err != nil {
logrus.Debugf("Failed to Marshal public key")
return nil, "", err
}
// TODO(diogo): Actually get the right alias from the certificate instead of
// alwars returning data.CanonicalRootRole
return data.NewECDSAPublicKey(pubBytes), data.CanonicalRootRole, nil
}
// Sign returns a signature for a given signature request
func sign(ctx *pkcs11.Ctx, session pkcs11.SessionHandle, pkcs11KeyID []byte, passRetriever passphrase.Retriever, payload []byte) ([]byte, error) {
err := login(ctx, session, passRetriever, pkcs11.CKU_USER, USER_PIN)
if err != nil {
return nil, fmt.Errorf("error logging in: %v", err)
}
defer ctx.Logout(session)
// Define the ECDSA Private key template
class := pkcs11.CKO_PRIVATE_KEY
privateKeyTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_CLASS, class),
pkcs11.NewAttribute(pkcs11.CKA_KEY_TYPE, pkcs11.CKK_ECDSA),
pkcs11.NewAttribute(pkcs11.CKA_ID, pkcs11KeyID),
}
if err := ctx.FindObjectsInit(session, privateKeyTemplate); err != nil {
return nil, err
}
obj, _, err := ctx.FindObjects(session, 1)
if err != nil {
return nil, err
}
if err = ctx.FindObjectsFinal(session); err != nil {
return nil, err
}
if len(obj) != 1 {
return nil, errors.New("length of objects found not 1")
}
var sig []byte
ctx.SignInit(session, []*pkcs11.Mechanism{pkcs11.NewMechanism(pkcs11.CKM_ECDSA, nil)}, obj[0])
// Get the SHA256 of the payload
digest := sha256.Sum256(payload)
sig, err = ctx.Sign(session, digest[:])
if err != nil {
logrus.Debugf("Error while signing: %s", err)
return nil, err
}
if sig == nil {
return nil, errors.New("Failed to create signature")
}
return sig[:], nil
}
func removeKey(ctx *pkcs11.Ctx, session pkcs11.SessionHandle, pkcs11KeyID []byte, passRetriever passphrase.Retriever, keyID string) error {
err := login(ctx, session, passRetriever, pkcs11.CKU_SO, SO_USER_PIN)
if err != nil {
return err
}
defer ctx.Logout(session)
template := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_TOKEN, true),
pkcs11.NewAttribute(pkcs11.CKA_ID, pkcs11KeyID),
//pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_PRIVATE_KEY),
pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_CERTIFICATE),
}
if err := ctx.FindObjectsInit(session, template); err != nil {
logrus.Printf("Failed to init: %s\n", err.Error())
return err
}
obj, b, err := ctx.FindObjects(session, 1)
if err != nil {
logrus.Printf("Failed to find: %s %v\n", err.Error(), b)
return err
}
if err := ctx.FindObjectsFinal(session); err != nil {
logrus.Printf("Failed to finalize: %s\n", err.Error())
return err
}
if len(obj) != 1 {
logrus.Printf("should have found one object")
return err
}
// Delete the certificate
err = ctx.DestroyObject(session, obj[0])
if err != nil {
logrus.Printf("Failed to delete cert")
return err
}
return nil
}
func listKeys(ctx *pkcs11.Ctx, session pkcs11.SessionHandle) (keys map[string]yubiSlot, err error) {
keys = make(map[string]yubiSlot)
findTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_TOKEN, true),
//pkcs11.NewAttribute(pkcs11.CKA_ID, pkcs11KeyID),
pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_CERTIFICATE),
}
attrTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_ID, []byte{0}),
pkcs11.NewAttribute(pkcs11.CKA_VALUE, []byte{0}),
}
if err = ctx.FindObjectsInit(session, findTemplate); err != nil {
logrus.Debugf("Failed to init: %s\n", err.Error())
return
}
objs, b, err := ctx.FindObjects(session, numSlots)
for err == nil {
var o []pkcs11.ObjectHandle
o, b, err = ctx.FindObjects(session, numSlots)
if err != nil {
continue
}
if len(o) == 0 {
break
}
objs = append(objs, o...)
}
if err != nil {
logrus.Debugf("Failed to find: %s %v\n", err.Error(), b)
if len(objs) == 0 {
return nil, err
}
}
if err = ctx.FindObjectsFinal(session); err != nil {
logrus.Debugf("Failed to finalize: %s\n", err.Error())
return
}
if len(objs) == 0 {
return nil, errors.New("No keys found in yubikey.")
}
logrus.Debugf("Found %d objects matching list filters", len(objs))
for _, obj := range objs {
var (
cert *x509.Certificate
slot []byte
)
// Retrieve the public-key material to be able to create a new HSMRSAKey
attr, err := ctx.GetAttributeValue(session, obj, attrTemplate)
if err != nil {
logrus.Debugf("Failed to get Attribute for: %v\n", obj)
continue
}
// Iterate through all the attributes of this key and saves CKA_PUBLIC_EXPONENT and CKA_MODULUS. Removes ordering specific issues.
for _, a := range attr {
if a.Type == pkcs11.CKA_ID {
slot = a.Value
}
if a.Type == pkcs11.CKA_VALUE {
cert, err = x509.ParseCertificate(a.Value)
if err != nil {
continue
}
if !data.ValidRole(cert.Subject.CommonName) {
continue
}
}
}
var ecdsaPubKey *ecdsa.PublicKey
switch cert.PublicKeyAlgorithm {
case x509.ECDSA:
ecdsaPubKey = cert.PublicKey.(*ecdsa.PublicKey)
default:
logrus.Infof("Unsupported x509 PublicKeyAlgorithm: %d", cert.PublicKeyAlgorithm)
continue
}
pubBytes, err := x509.MarshalPKIXPublicKey(ecdsaPubKey)
if err != nil {
logrus.Debugf("Failed to Marshal public key")
continue
}
keys[data.NewECDSAPublicKey(pubBytes).ID()] = yubiSlot{
role: cert.Subject.CommonName,
slotID: slot,
}
}
return
}
func getNextEmptySlot(ctx *pkcs11.Ctx, session pkcs11.SessionHandle) ([]byte, error) {
findTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_TOKEN, true),
}
attrTemplate := []*pkcs11.Attribute{
pkcs11.NewAttribute(pkcs11.CKA_ID, []byte{0}),
}
if err := ctx.FindObjectsInit(session, findTemplate); err != nil {
logrus.Debugf("Failed to init: %s\n", err.Error())
return nil, err
}
objs, b, err := ctx.FindObjects(session, numSlots)
for err == nil {
var o []pkcs11.ObjectHandle
o, b, err = ctx.FindObjects(session, numSlots)
if err != nil {
continue
}
if len(o) == 0 {
break
}
objs = append(objs, o...)
}
taken := make([]bool, numSlots)
if err != nil {
logrus.Debugf("Failed to find: %s %v\n", err.Error(), b)
return nil, err
}
for _, obj := range objs {
// Retrieve the public-key material to be able to create a new HSMRSAKey
attr, err := ctx.GetAttributeValue(session, obj, attrTemplate)
if err != nil {
logrus.Debugf("Failed to get Attribute for: %v\n", obj)
continue
}
// Iterate through all the attributes of this key and saves CKA_PUBLIC_EXPONENT and CKA_MODULUS. Removes ordering specific issues.
for _, a := range attr {
if a.Type == pkcs11.CKA_ID {
if len(a.Value) < 1 {
continue
}
// max 50 slots so a single byte will always represent
// all possible slots positions
slotNum := int(a.Value[0])
if slotNum >= len(taken) {
// defensive
continue
}
taken[slotNum] = true
}
}
}
for i := 0; i < numSlots; i++ {
if !taken[i] {
return []byte{byte(i)}, nil
}
}
return nil, errors.New("Yubikey has no available slots.")
}
type YubiKeyStore struct {
passRetriever passphrase.Retriever
keys map[string]yubiSlot
}
func NewYubiKeyStore(passphraseRetriever passphrase.Retriever) *YubiKeyStore {
s := &YubiKeyStore{
passRetriever: passphraseRetriever,
keys: make(map[string]yubiSlot),
}
s.ListKeys() // populate keys field
return s
}
func (s *YubiKeyStore) ListKeys() map[string]string {
if len(s.keys) > 0 {
return buildKeyMap(s.keys)
}
ctx, session, err := SetupHSMEnv(pkcs11Lib)
if err != nil {
return nil
}
defer cleanup(ctx, session)
keys, err := listKeys(ctx, session)
if err != nil {
return nil
}
s.keys = keys
return buildKeyMap(keys)
}
func (s *YubiKeyStore) AddKey(keyID, role string, privKey data.PrivateKey) error {
// We only allow adding root keys for now
if role != data.CanonicalRootRole {
return fmt.Errorf("yubikey only supports storing root keys, got %s for key: %s\n", role, keyID)
}
ctx, session, err := SetupHSMEnv(pkcs11Lib)
if err != nil {
return err
}
defer cleanup(ctx, session)
if k, ok := s.keys[keyID]; ok {
if k.role == role {
}
}
slot, err := getNextEmptySlot(ctx, session)
if err != nil {
return err
}
logrus.Debugf("Using yubikey slot %v", slot)
return addECDSAKey(ctx, session, privKey, slot, s.passRetriever, role)
}
func (s *YubiKeyStore) GetKey(keyID string) (data.PrivateKey, string, error) {
ctx, session, err := SetupHSMEnv(pkcs11Lib)
if err != nil {
return nil, "", err
}
defer cleanup(ctx, session)
key, ok := s.keys[keyID]
if !ok {
return nil, "", errors.New("no matching keys found inside of yubikey")
}
pubKey, alias, err := getECDSAKey(ctx, session, key.slotID)
if err != nil {
return nil, "", err
}
// Check to see if we're returning the intended keyID
if pubKey.ID() != keyID {
return nil, "", fmt.Errorf("expected root key: %s, but found: %s\n", keyID, pubKey.ID())
}
privKey := NewYubiPrivateKey(key.slotID, *pubKey, s.passRetriever)
if privKey == nil {
return nil, "", errors.New("could not initialize new YubiPrivateKey")
}
return privKey, alias, err
}
func (s *YubiKeyStore) RemoveKey(keyID string) error {
ctx, session, err := SetupHSMEnv(pkcs11Lib)
if err != nil {
return nil
}
defer cleanup(ctx, session)
key, ok := s.keys[keyID]
if !ok {
return errors.New("Key not present in yubikey")
}
return removeKey(ctx, session, key.slotID, s.passRetriever, keyID)
}
func (s *YubiKeyStore) ExportKey(keyID string) ([]byte, error) {
logrus.Debugf("Attempting to export: %s key inside of YubiKeyStore", keyID)
return nil, errors.New("Keys cannot be exported from a Yubikey.")
}
func (s *YubiKeyStore) ImportKey(pemBytes []byte, keyID string) error {
logrus.Debugf("Attempting to import: %s key inside of YubiKeyStore", keyID)
privKey, _, err := trustmanager.GetPasswdDecryptBytes(s.passRetriever, pemBytes, "imported", "root")
if err != nil {
return err
}
return s.AddKey(privKey.ID(), "root", privKey)
}
func cleanup(ctx *pkcs11.Ctx, session pkcs11.SessionHandle) {
ctx.CloseSession(session)
ctx.Finalize()
ctx.Destroy()
}
// SetupHSMEnv is a method that depends on the existences
func SetupHSMEnv(libraryPath string) (*pkcs11.Ctx, pkcs11.SessionHandle, error) {
p := pkcs11.New(libraryPath)
if p == nil {
return nil, 0, errors.New("Failed to init library")
}
if err := p.Initialize(); err != nil {
return nil, 0, fmt.Errorf("Initialize error %s\n", err.Error())
}
slots, err := p.GetSlotList(true)
if err != nil {
return nil, 0, fmt.Errorf("Failed to list HSM slots %s", err)
}
// Check to see if we got any slots from the HSM.
if len(slots) < 1 {
return nil, 0, fmt.Errorf("No HSM Slots found")
}
// CKF_SERIAL_SESSION: TRUE if cryptographic functions are performed in serial with the application; FALSE if the functions may be performed in parallel with the application.
// CKF_RW_SESSION: TRUE if the session is read/write; FALSE if the session is read-only
session, err := p.OpenSession(slots[0], pkcs11.CKF_SERIAL_SESSION|pkcs11.CKF_RW_SESSION)
if err != nil {
return nil, 0, fmt.Errorf("Failed to Start Session with HSM %s", err)
}
return p, session, nil
}
func login(ctx *pkcs11.Ctx, session pkcs11.SessionHandle, passRetriever passphrase.Retriever, userFlag uint, defaultPassw string) error {
// try default password
err := ctx.Login(session, userFlag, defaultPassw)
if err == nil {
return nil
}
// default failed, ask user for password
for attempts := 0; ; attempts++ {
var (
giveup bool
err error
user string
)
if userFlag == pkcs11.CKU_SO {
user = "SO Pin"
} else {
user = "User Pin"
}
passwd, giveup, err := passRetriever(user, "yubikey", false, attempts)
// Check if the passphrase retriever got an error or if it is telling us to give up
if giveup || err != nil {
return trustmanager.ErrPasswordInvalid{}
}
if attempts > 2 {
return trustmanager.ErrAttemptsExceeded{}
}
// Try to convert PEM encoded bytes back to a PrivateKey using the passphrase
err = ctx.Login(session, userFlag, passwd)
if err == nil {
return nil
}
}
return nil
}
func buildKeyMap(keys map[string]yubiSlot) map[string]string {
res := make(map[string]string)
for k, v := range keys {
res[k] = v.role
}
return res
}