chore: vendor

vendor/github.com/theupdateframework/notary/trustmanager/errors.go

@@ -0,0 +1,31 @@
+package trustmanager
+
+import "fmt"
+
+// ErrAttemptsExceeded is returned when too many attempts have been made to decrypt a key
+type ErrAttemptsExceeded struct{}
+
+// ErrAttemptsExceeded is returned when too many attempts have been made to decrypt a key
+func (err ErrAttemptsExceeded) Error() string {
+	return "maximum number of passphrase attempts exceeded"
+}
+
+// ErrPasswordInvalid is returned when signing fails. It could also mean the signing
+// key file was corrupted, but we have no way to distinguish.
+type ErrPasswordInvalid struct{}
+
+// ErrPasswordInvalid is returned when signing fails. It could also mean the signing
+// key file was corrupted, but we have no way to distinguish.
+func (err ErrPasswordInvalid) Error() string {
+	return "password invalid, operation has failed."
+}
+
+// ErrKeyNotFound is returned when the keystore fails to retrieve a specific key.
+type ErrKeyNotFound struct {
+	KeyID string
+}
+
+// ErrKeyNotFound is returned when the keystore fails to retrieve a specific key.
+func (err ErrKeyNotFound) Error() string {
+	return fmt.Sprintf("signing key not found: %s", err.KeyID)
+}

vendor/github.com/theupdateframework/notary/trustmanager/importLogic.md

@@ -0,0 +1,8 @@
+###This document is intended as an overview of the logic we use for importing keys
+
+# A flowchart to detail the logic of our import function in `utils/keys.go` (`func ImportKeys`)
+
+![alt text](http://i.imgur.com/HQICWeO.png "Flowchart of key import logic")
+
+### Should this logic change, you can edit this image at `https://www.draw.io/i/HQICWeO`
+

vendor/github.com/theupdateframework/notary/trustmanager/interfaces.go

@@ -0,0 +1,54 @@
+package trustmanager
+
+import (
+	"github.com/theupdateframework/notary/tuf/data"
+)
+
+// Storage implements the bare bones primitives (no hierarchy)
+type Storage interface {
+	// Add writes a file to the specified location, returning an error if this
+	// is not possible (reasons may include permissions errors). The path is cleaned
+	// before being made absolute against the store's base dir.
+	Set(fileName string, data []byte) error
+
+	// Remove deletes a file from the store relative to the store's base directory.
+	// The path is cleaned before being made absolute to ensure no path traversal
+	// outside the base directory is possible.
+	Remove(fileName string) error
+
+	// Get returns the file content found at fileName relative to the base directory
+	// of the file store. The path is cleaned before being made absolute to ensure
+	// path traversal outside the store is not possible. If the file is not found
+	// an error to that effect is returned.
+	Get(fileName string) ([]byte, error)
+
+	// ListFiles returns a list of paths relative to the base directory of the
+	// filestore. Any of these paths must be retrievable via the
+	// Storage.Get method.
+	ListFiles() []string
+
+	// Location returns a human readable name indicating where the implementer
+	// is storing keys
+	Location() string
+}
+
+// KeyInfo stores the role and gun for a corresponding private key ID
+// It is assumed that each private key ID is unique
+type KeyInfo struct {
+	Gun  data.GUN
+	Role data.RoleName
+}
+
+// KeyStore is a generic interface for private key storage
+type KeyStore interface {
+	// AddKey adds a key to the KeyStore, and if the key already exists,
+	// succeeds.  Otherwise, returns an error if it cannot add.
+	AddKey(keyInfo KeyInfo, privKey data.PrivateKey) error
+	// Should fail with ErrKeyNotFound if the keystore is operating normally
+	// and knows that it does not store the requested key.
+	GetKey(keyID string) (data.PrivateKey, data.RoleName, error)
+	GetKeyInfo(keyID string) (KeyInfo, error)
+	ListKeys() map[string]KeyInfo
+	RemoveKey(keyID string) error
+	Name() string
+}

vendor/github.com/theupdateframework/notary/trustmanager/keys.go

@@ -0,0 +1,246 @@
+package trustmanager
+
+import (
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary"
+	tufdata "github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+// Exporter is a simple interface for the two functions we need from the Storage interface
+type Exporter interface {
+	Get(string) ([]byte, error)
+	ListFiles() []string
+}
+
+// Importer is a simple interface for the one function we need from the Storage interface
+type Importer interface {
+	Set(string, []byte) error
+}
+
+// ExportKeysByGUN exports all keys filtered to a GUN
+func ExportKeysByGUN(to io.Writer, s Exporter, gun string) error {
+	keys := s.ListFiles()
+	sort.Strings(keys) // ensure consistency. ListFiles has no order guarantee
+	for _, loc := range keys {
+		keyFile, err := s.Get(loc)
+		if err != nil {
+			logrus.Warn("Could not parse key file at ", loc)
+			continue
+		}
+		block, _ := pem.Decode(keyFile)
+		keyGun := block.Headers["gun"]
+		if keyGun == gun { // must be full GUN match
+			if err := ExportKeys(to, s, loc); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// ExportKeysByID exports all keys matching the given ID
+func ExportKeysByID(to io.Writer, s Exporter, ids []string) error {
+	want := make(map[string]struct{})
+	for _, id := range ids {
+		want[id] = struct{}{}
+	}
+	keys := s.ListFiles()
+	for _, k := range keys {
+		id := filepath.Base(k)
+		if _, ok := want[id]; ok {
+			if err := ExportKeys(to, s, k); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// ExportKeys copies a key from the store to the io.Writer
+func ExportKeys(to io.Writer, s Exporter, from string) error {
+	// get PEM block
+	k, err := s.Get(from)
+	if err != nil {
+		return err
+	}
+
+	// parse PEM blocks if there are more than one
+	for block, rest := pem.Decode(k); block != nil; block, rest = pem.Decode(rest) {
+		// add from path in a header for later import
+		block.Headers["path"] = from
+		// write serialized PEM
+		err = pem.Encode(to, block)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ImportKeys expects an io.Reader containing one or more PEM blocks.
+// It reads PEM blocks one at a time until pem.Decode returns a nil
+// block.
+// Each block is written to the subpath indicated in the "path" PEM
+// header. If the file already exists, the file is truncated. Multiple
+// adjacent PEMs with the same "path" header are appended together.
+func ImportKeys(from io.Reader, to []Importer, fallbackRole string, fallbackGUN string, passRet notary.PassRetriever) error {
+	// importLogic.md contains a small flowchart I made to clear up my understand while writing the cases in this function
+	// it is very rough, but it may help while reading this piece of code
+	data, err := ioutil.ReadAll(from)
+	if err != nil {
+		return err
+	}
+	var (
+		writeTo   string
+		toWrite   []byte
+		errBlocks []string
+	)
+	for block, rest := pem.Decode(data); block != nil; block, rest = pem.Decode(rest) {
+		handleLegacyPath(block)
+		setFallbacks(block, fallbackGUN, fallbackRole)
+
+		loc, err := checkValidity(block)
+		if err != nil {
+			// already logged in checkValidity
+			errBlocks = append(errBlocks, err.Error())
+			continue
+		}
+
+		// the path header is not of any use once we've imported the key so strip it away
+		delete(block.Headers, "path")
+
+		// we are now all set for import but let's first encrypt the key
+		blockBytes := pem.EncodeToMemory(block)
+		// check if key is encrypted, note: if it is encrypted at this point, it will have had a path header
+		if privKey, err := utils.ParsePEMPrivateKey(blockBytes, ""); err == nil {
+			// Key is not encrypted- ask for a passphrase and encrypt this key
+			var chosenPassphrase string
+			for attempts := 0; ; attempts++ {
+				var giveup bool
+				chosenPassphrase, giveup, err = passRet(loc, block.Headers["role"], true, attempts)
+				if err == nil {
+					break
+				}
+				if giveup || attempts > 10 {
+					return errors.New("maximum number of passphrase attempts exceeded")
+				}
+			}
+			blockBytes, err = utils.ConvertPrivateKeyToPKCS8(privKey, tufdata.RoleName(block.Headers["role"]), tufdata.GUN(block.Headers["gun"]), chosenPassphrase)
+			if err != nil {
+				return errors.New("failed to encrypt key with given passphrase")
+			}
+		}
+
+		if loc != writeTo {
+			// next location is different from previous one. We've finished aggregating
+			// data for the previous file. If we have data, write the previous file,
+			// clear toWrite and set writeTo to the next path we're going to write
+			if toWrite != nil {
+				if err = importToStores(to, writeTo, toWrite); err != nil {
+					return err
+				}
+			}
+			// set up for aggregating next file's data
+			toWrite = nil
+			writeTo = loc
+		}
+
+		toWrite = append(toWrite, blockBytes...)
+	}
+	if toWrite != nil { // close out final iteration if there's data left
+		return importToStores(to, writeTo, toWrite)
+	}
+	if len(errBlocks) > 0 {
+		return fmt.Errorf("failed to import all keys: %s", strings.Join(errBlocks, ", "))
+	}
+	return nil
+}
+
+func handleLegacyPath(block *pem.Block) {
+	// if there is a legacy path then we set the gun header from this path
+	// this is the case when a user attempts to import a key bundle generated by an older client
+	if rawPath := block.Headers["path"]; rawPath != "" && rawPath != filepath.Base(rawPath) {
+		// this is a legacy filepath and we should try to deduce the gun name from it
+		pathWOFileName := filepath.Dir(rawPath)
+		if strings.HasPrefix(pathWOFileName, notary.NonRootKeysSubdir) {
+			// remove the notary keystore-specific segment of the path, and any potential leading or trailing slashes
+			gunName := strings.Trim(strings.TrimPrefix(pathWOFileName, notary.NonRootKeysSubdir), "/")
+			if gunName != "" {
+				block.Headers["gun"] = gunName
+			}
+		}
+		block.Headers["path"] = filepath.Base(rawPath)
+	}
+}
+
+func setFallbacks(block *pem.Block, fallbackGUN, fallbackRole string) {
+	if block.Headers["gun"] == "" {
+		if fallbackGUN != "" {
+			block.Headers["gun"] = fallbackGUN
+		}
+	}
+
+	if block.Headers["role"] == "" {
+		if fallbackRole == "" {
+			block.Headers["role"] = notary.DefaultImportRole
+		} else {
+			block.Headers["role"] = fallbackRole
+		}
+	}
+}
+
+// checkValidity ensures the fields in the pem headers are valid and parses out the location.
+// While importing a collection of keys, errors from this function should result in only the
+// current pem block being skipped.
+func checkValidity(block *pem.Block) (string, error) {
+	// A root key or a delegations key should not have a gun
+	// Note that a key that is not any of the canonical roles (except root) is a delegations key and should not have a gun
+	switch block.Headers["role"] {
+	case tufdata.CanonicalSnapshotRole.String(), tufdata.CanonicalTargetsRole.String(), tufdata.CanonicalTimestampRole.String():
+		// check if the key is missing a gun header or has an empty gun and error out since we don't know what gun it belongs to
+		if block.Headers["gun"] == "" {
+			logrus.Warnf("failed to import key (%s) to store: Cannot have canonical role key without a gun, don't know what gun it belongs to", block.Headers["path"])
+			return "", errors.New("invalid key pem block")
+		}
+	default:
+		delete(block.Headers, "gun")
+	}
+
+	loc, ok := block.Headers["path"]
+	// only if the path isn't specified do we get into this parsing path logic
+	if !ok || loc == "" {
+		// if the path isn't specified, we will try to infer the path rel to trust dir from the role (and then gun)
+		// parse key for the keyID which we will save it by.
+		// if the key is encrypted at this point, we will generate an error and continue since we don't know the ID to save it by
+
+		decodedKey, err := utils.ParsePEMPrivateKey(pem.EncodeToMemory(block), "")
+		if err != nil {
+			logrus.Warn("failed to import key to store: Invalid key generated, key may be encrypted and does not contain path header")
+			return "", errors.New("invalid key pem block")
+		}
+		loc = decodedKey.ID()
+	}
+	return loc, nil
+}
+
+func importToStores(to []Importer, path string, bytes []byte) error {
+	var err error
+	for _, i := range to {
+		if err = i.Set(path, bytes); err != nil {
+			logrus.Errorf("failed to import key to store: %s", err.Error())
+			continue
+		}
+		break
+	}
+	return err
+}

vendor/github.com/theupdateframework/notary/trustmanager/keystore.go

@@ -0,0 +1,262 @@
+package trustmanager
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary"
+	store "github.com/theupdateframework/notary/storage"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+type keyInfoMap map[string]KeyInfo
+
+type cachedKey struct {
+	role data.RoleName
+	key  data.PrivateKey
+}
+
+// GenericKeyStore is a wrapper for Storage instances that provides
+// translation between the []byte form and Public/PrivateKey objects
+type GenericKeyStore struct {
+	store Storage
+	sync.Mutex
+	notary.PassRetriever
+	cachedKeys map[string]*cachedKey
+	keyInfoMap
+}
+
+// NewKeyFileStore returns a new KeyFileStore creating a private directory to
+// hold the keys.
+func NewKeyFileStore(baseDir string, p notary.PassRetriever) (*GenericKeyStore, error) {
+	fileStore, err := store.NewPrivateKeyFileStorage(baseDir, notary.KeyExtension)
+	if err != nil {
+		return nil, err
+	}
+	return NewGenericKeyStore(fileStore, p), nil
+}
+
+// NewKeyMemoryStore returns a new KeyMemoryStore which holds keys in memory
+func NewKeyMemoryStore(p notary.PassRetriever) *GenericKeyStore {
+	memStore := store.NewMemoryStore(nil)
+	return NewGenericKeyStore(memStore, p)
+}
+
+// NewGenericKeyStore creates a GenericKeyStore wrapping the provided
+// Storage instance, using the PassRetriever to enc/decrypt keys
+func NewGenericKeyStore(s Storage, p notary.PassRetriever) *GenericKeyStore {
+	ks := GenericKeyStore{
+		store:         s,
+		PassRetriever: p,
+		cachedKeys:    make(map[string]*cachedKey),
+		keyInfoMap:    make(keyInfoMap),
+	}
+	ks.loadKeyInfo()
+	return &ks
+}
+
+func generateKeyInfoMap(s Storage) map[string]KeyInfo {
+	keyInfoMap := make(map[string]KeyInfo)
+	for _, keyPath := range s.ListFiles() {
+		d, err := s.Get(keyPath)
+		if err != nil {
+			logrus.Error(err)
+			continue
+		}
+		keyID, keyInfo, err := KeyInfoFromPEM(d, keyPath)
+		if err != nil {
+			logrus.Error(err)
+			continue
+		}
+		keyInfoMap[keyID] = keyInfo
+	}
+	return keyInfoMap
+}
+
+func (s *GenericKeyStore) loadKeyInfo() {
+	s.keyInfoMap = generateKeyInfoMap(s.store)
+}
+
+// GetKeyInfo returns the corresponding gun and role key info for a keyID
+func (s *GenericKeyStore) GetKeyInfo(keyID string) (KeyInfo, error) {
+	if info, ok := s.keyInfoMap[keyID]; ok {
+		return info, nil
+	}
+	return KeyInfo{}, fmt.Errorf("Could not find info for keyID %s", keyID)
+}
+
+// AddKey stores the contents of a PEM-encoded private key as a PEM block
+func (s *GenericKeyStore) AddKey(keyInfo KeyInfo, privKey data.PrivateKey) error {
+	var (
+		chosenPassphrase string
+		giveup           bool
+		err              error
+		pemPrivKey       []byte
+	)
+	s.Lock()
+	defer s.Unlock()
+	if keyInfo.Role == data.CanonicalRootRole || data.IsDelegation(keyInfo.Role) || !data.ValidRole(keyInfo.Role) {
+		keyInfo.Gun = ""
+	}
+	keyID := privKey.ID()
+	for attempts := 0; ; attempts++ {
+		chosenPassphrase, giveup, err = s.PassRetriever(keyID, keyInfo.Role.String(), true, attempts)
+		if err == nil {
+			break
+		}
+		if giveup || attempts > 10 {
+			return ErrAttemptsExceeded{}
+		}
+	}
+
+	pemPrivKey, err = utils.ConvertPrivateKeyToPKCS8(privKey, keyInfo.Role, keyInfo.Gun, chosenPassphrase)
+
+	if err != nil {
+		return err
+	}
+
+	s.cachedKeys[keyID] = &cachedKey{role: keyInfo.Role, key: privKey}
+	err = s.store.Set(keyID, pemPrivKey)
+	if err != nil {
+		return err
+	}
+	s.keyInfoMap[privKey.ID()] = keyInfo
+	return nil
+}
+
+// GetKey returns the PrivateKey given a KeyID
+func (s *GenericKeyStore) GetKey(keyID string) (data.PrivateKey, data.RoleName, error) {
+	s.Lock()
+	defer s.Unlock()
+
+	cachedKeyEntry, ok := s.cachedKeys[keyID]
+	if ok {
+		return cachedKeyEntry.key, cachedKeyEntry.role, nil
+	}
+
+	role, err := getKeyRole(s.store, keyID)
+	if err != nil {
+		return nil, "", err
+	}
+
+	keyBytes, err := s.store.Get(keyID)
+	if err != nil {
+		return nil, "", err
+	}
+
+	// See if the key is encrypted. If its encrypted we'll fail to parse the private key
+	privKey, err := utils.ParsePEMPrivateKey(keyBytes, "")
+	if err != nil {
+		privKey, _, err = GetPasswdDecryptBytes(s.PassRetriever, keyBytes, keyID, string(role))
+		if err != nil {
+			return nil, "", err
+		}
+	}
+	s.cachedKeys[keyID] = &cachedKey{role: role, key: privKey}
+	return privKey, role, nil
+}
+
+// ListKeys returns a list of unique PublicKeys present on the KeyFileStore, by returning a copy of the keyInfoMap
+func (s *GenericKeyStore) ListKeys() map[string]KeyInfo {
+	return copyKeyInfoMap(s.keyInfoMap)
+}
+
+// RemoveKey removes the key from the keyfilestore
+func (s *GenericKeyStore) RemoveKey(keyID string) error {
+	s.Lock()
+	defer s.Unlock()
+	delete(s.cachedKeys, keyID)
+
+	err := s.store.Remove(keyID)
+	if err != nil {
+		return err
+	}
+
+	delete(s.keyInfoMap, keyID)
+	return nil
+}
+
+// Name returns a user friendly name for the location this store
+// keeps its data
+func (s *GenericKeyStore) Name() string {
+	return s.store.Location()
+}
+
+// copyKeyInfoMap returns a deep copy of the passed-in keyInfoMap
+func copyKeyInfoMap(keyInfoMap map[string]KeyInfo) map[string]KeyInfo {
+	copyMap := make(map[string]KeyInfo)
+	for keyID, keyInfo := range keyInfoMap {
+		copyMap[keyID] = KeyInfo{Role: keyInfo.Role, Gun: keyInfo.Gun}
+	}
+	return copyMap
+}
+
+// KeyInfoFromPEM attempts to get a keyID and KeyInfo from the filename and PEM bytes of a key
+func KeyInfoFromPEM(pemBytes []byte, filename string) (string, KeyInfo, error) {
+	var keyID string
+	keyID = filepath.Base(filename)
+	role, gun, err := utils.ExtractPrivateKeyAttributes(pemBytes)
+	if err != nil {
+		return "", KeyInfo{}, err
+	}
+	return keyID, KeyInfo{Gun: gun, Role: role}, nil
+}
+
+// getKeyRole finds the role for the given keyID. It attempts to look
+// both in the newer format PEM headers, and also in the legacy filename
+// format. It returns: the role, and an error
+func getKeyRole(s Storage, keyID string) (data.RoleName, error) {
+	name := strings.TrimSpace(strings.TrimSuffix(filepath.Base(keyID), filepath.Ext(keyID)))
+
+	for _, file := range s.ListFiles() {
+		filename := filepath.Base(file)
+		if strings.HasPrefix(filename, name) {
+			d, err := s.Get(file)
+			if err != nil {
+				return "", err
+			}
+
+			role, _, err := utils.ExtractPrivateKeyAttributes(d)
+			if err != nil {
+				return "", err
+			}
+			return role, nil
+		}
+	}
+	return "", ErrKeyNotFound{KeyID: keyID}
+}
+
+// GetPasswdDecryptBytes gets the password to decrypt the given pem bytes.
+// Returns the password and private key
+func GetPasswdDecryptBytes(passphraseRetriever notary.PassRetriever, pemBytes []byte, name, alias string) (data.PrivateKey, string, error) {
+	var (
+		passwd  string
+		privKey data.PrivateKey
+	)
+	for attempts := 0; ; attempts++ {
+		var (
+			giveup bool
+			err    error
+		)
+		if attempts > 10 {
+			return nil, "", ErrAttemptsExceeded{}
+		}
+		passwd, giveup, err = passphraseRetriever(name, alias, false, attempts)
+		// Check if the passphrase retriever got an error or if it is telling us to give up
+		if giveup || err != nil {
+			return nil, "", ErrPasswordInvalid{}
+		}
+
+		// Try to convert PEM encoded bytes back to a PrivateKey using the passphrase
+		privKey, err = utils.ParsePEMPrivateKey(pemBytes, passwd)
+		if err == nil {
+			// We managed to parse the PrivateKey. We've succeeded!
+			break
+		}
+	}
+	return privKey, passwd, nil
+}

vendor/github.com/theupdateframework/notary/trustmanager/yubikey/import.go

@@ -0,0 +1,60 @@
+//go:build pkcs11
+// +build pkcs11
+
+package yubikey
+
+import (
+	"encoding/pem"
+	"errors"
+
+	"github.com/theupdateframework/notary"
+	"github.com/theupdateframework/notary/trustmanager"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+// YubiImport is a wrapper around the YubiStore that allows us to import private
+// keys to the yubikey
+type YubiImport struct {
+	dest          *YubiStore
+	passRetriever notary.PassRetriever
+}
+
+// NewImporter returns a wrapper for the YubiStore provided that enables importing
+// keys via the simple Set(string, []byte) interface
+func NewImporter(ys *YubiStore, ret notary.PassRetriever) *YubiImport {
+	return &YubiImport{
+		dest:          ys,
+		passRetriever: ret,
+	}
+}
+
+// Set determines if we are allowed to set the given key on the Yubikey and
+// calls through to YubiStore.AddKey if it's valid
+func (s *YubiImport) Set(name string, bytes []byte) error {
+	block, _ := pem.Decode(bytes)
+	if block == nil {
+		return errors.New("invalid PEM data, could not parse")
+	}
+	role, ok := block.Headers["role"]
+	if !ok {
+		return errors.New("no role found for key")
+	}
+	ki := trustmanager.KeyInfo{
+		// GUN is ignored by YubiStore
+		Role: data.RoleName(role),
+	}
+	privKey, err := utils.ParsePEMPrivateKey(bytes, "")
+	if err != nil {
+		privKey, _, err = trustmanager.GetPasswdDecryptBytes(
+			s.passRetriever,
+			bytes,
+			name,
+			ki.Role.String(),
+		)
+		if err != nil {
+			return err
+		}
+	}
+	return s.dest.AddKey(ki, privKey)
+}

vendor/github.com/theupdateframework/notary/trustmanager/yubikey/non_pkcs11.go

@@ -0,0 +1,9 @@
+// go list ./... and go test ./... will not pick up this package without this
+// file, because go ? ./... does not honor build tags.
+
+// e.g. "go list -tags pkcs11 ./..." will not list this package if all the
+// files in it have a build tag.
+
+// See https://github.com/golang/go/issues/11246
+
+package yubikey

vendor/github.com/theupdateframework/notary/trustmanager/yubikey/pkcs11_darwin.go

@@ -0,0 +1,10 @@
+//go:build pkcs11 && darwin
+// +build pkcs11,darwin
+
+package yubikey
+
+var possiblePkcs11Libs = []string{
+	"/usr/local/lib/libykcs11.dylib",
+	"/usr/local/docker/lib/libykcs11.dylib",
+	"/usr/local/docker-experimental/lib/libykcs11.dylib",
+}

vendor/github.com/theupdateframework/notary/trustmanager/yubikey/pkcs11_interface.go

@@ -0,0 +1,41 @@
+//go:build pkcs11
+// +build pkcs11
+
+// an interface around the pkcs11 library, so that things can be mocked out
+// for testing
+
+package yubikey
+
+import "github.com/miekg/pkcs11"
+
+// IPKCS11 is an interface for wrapping github.com/miekg/pkcs11
+type pkcs11LibLoader func(module string) IPKCS11Ctx
+
+func defaultLoader(module string) IPKCS11Ctx {
+	return pkcs11.New(module)
+}
+
+// IPKCS11Ctx is an interface for wrapping the parts of
+// github.com/miekg/pkcs11.Ctx that yubikeystore requires
+type IPKCS11Ctx interface {
+	Destroy()
+	Initialize() error
+	Finalize() error
+	GetSlotList(tokenPresent bool) ([]uint, error)
+	OpenSession(slotID uint, flags uint) (pkcs11.SessionHandle, error)
+	CloseSession(sh pkcs11.SessionHandle) error
+	Login(sh pkcs11.SessionHandle, userType uint, pin string) error
+	Logout(sh pkcs11.SessionHandle) error
+	CreateObject(sh pkcs11.SessionHandle, temp []*pkcs11.Attribute) (
+		pkcs11.ObjectHandle, error)
+	DestroyObject(sh pkcs11.SessionHandle, oh pkcs11.ObjectHandle) error
+	GetAttributeValue(sh pkcs11.SessionHandle, o pkcs11.ObjectHandle,
+		a []*pkcs11.Attribute) ([]*pkcs11.Attribute, error)
+	FindObjectsInit(sh pkcs11.SessionHandle, temp []*pkcs11.Attribute) error
+	FindObjects(sh pkcs11.SessionHandle, max int) (
+		[]pkcs11.ObjectHandle, bool, error)
+	FindObjectsFinal(sh pkcs11.SessionHandle) error
+	SignInit(sh pkcs11.SessionHandle, m []*pkcs11.Mechanism,
+		o pkcs11.ObjectHandle) error
+	Sign(sh pkcs11.SessionHandle, message []byte) ([]byte, error)
+}

vendor/github.com/theupdateframework/notary/trustmanager/yubikey/pkcs11_linux.go

@@ -0,0 +1,13 @@
+//go:build pkcs11 && linux
+// +build pkcs11,linux
+
+package yubikey
+
+var possiblePkcs11Libs = []string{
+	"/usr/lib/libykcs11.so",
+	"/usr/lib/libykcs11.so.1", // yubico-piv-tool on Fedora installs here
+	"/usr/lib64/libykcs11.so",
+	"/usr/lib64/libykcs11.so.1", // yubico-piv-tool on Fedora installs here
+	"/usr/lib/x86_64-linux-gnu/libykcs11.so",
+	"/usr/local/lib/libykcs11.so",
+}

vendor/github.com/theupdateframework/notary/trustmanager/yubikey/yubikeystore.go

@@ -0,0 +1,925 @@
+//go:build pkcs11
+// +build pkcs11
+
+package yubikey
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"os"
+	"time"
+
+	"github.com/miekg/pkcs11"
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary"
+	"github.com/theupdateframework/notary/trustmanager"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/signed"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+const (
+	// UserPin is the user pin of a yubikey (in PIV parlance, is the PIN)
+	UserPin = "123456"
+	// SOUserPin is the "Security Officer" user pin - this is the PIV management
+	// (MGM) key, which is different than the admin pin of the Yubikey PGP interface
+	// (which in PIV parlance is the PUK, and defaults to 12345678)
+	SOUserPin = "010203040506070801020304050607080102030405060708"
+	numSlots  = 4 // number of slots in the yubikey
+
+	// KeymodeNone means that no touch or PIN is required to sign with the yubikey
+	KeymodeNone = 0
+	// KeymodeTouch means that only touch is required to sign with the yubikey
+	KeymodeTouch = 1
+	// KeymodePinOnce means that the pin entry is required once the first time to sign with the yubikey
+	KeymodePinOnce = 2
+	// KeymodePinAlways means that pin entry is required every time to sign with the yubikey
+	KeymodePinAlways = 4
+
+	// the key size, when importing a key into yubikey, MUST be 32 bytes
+	ecdsaPrivateKeySize = 32
+
+	sigAttempts = 5
+)
+
+// what key mode to use when generating keys
+var (
+	yubikeyKeymode = KeymodeTouch | KeymodePinOnce
+	// order in which to prefer token locations on the yubikey.
+	// corresponds to: 9c, 9e, 9d, 9a
+	slotIDs = []int{2, 1, 3, 0}
+)
+
+// SetYubikeyKeyMode - sets the mode when generating yubikey keys.
+// This is to be used for testing.  It does nothing if not building with tag
+// pkcs11.
+func SetYubikeyKeyMode(keyMode int) error {
+	// technically 7 (1 | 2 | 4) is valid, but KeymodePinOnce +
+	// KeymdoePinAlways don't really make sense together
+	if keyMode < 0 || keyMode > 5 {
+		return errors.New("Invalid key mode")
+	}
+	yubikeyKeymode = keyMode
+	return nil
+}
+
+// SetTouchToSignUI - allows configurable UX for notifying a user that they
+// need to touch the yubikey to sign. The callback may be used to provide a
+// mechanism for updating a GUI (such as removing a modal) after the touch
+// has been made
+func SetTouchToSignUI(notifier func(), callback func()) {
+	touchToSignUI = notifier
+	if callback != nil {
+		touchDoneCallback = callback
+	}
+}
+
+var touchToSignUI = func() {
+	fmt.Println("Please touch the attached Yubikey to perform signing.")
+}
+
+var touchDoneCallback = func() {
+	// noop
+}
+
+var pkcs11Lib string
+
+func init() {
+	for _, loc := range possiblePkcs11Libs {
+		_, err := os.Stat(loc)
+		if err == nil {
+			p := pkcs11.New(loc)
+			if p != nil {
+				pkcs11Lib = loc
+				return
+			}
+		}
+	}
+}
+
+// ErrBackupFailed is returned when a YubiStore fails to back up a key that
+// is added
+type ErrBackupFailed struct {
+	err string
+}
+
+func (err ErrBackupFailed) Error() string {
+	return fmt.Sprintf("Failed to backup private key to: %s", err.err)
+}
+
+// An error indicating that the HSM is not present (as opposed to failing),
+// i.e. that we can confidently claim that the key is not stored in the HSM
+// without notifying the user about a missing or failing HSM.
+type errHSMNotPresent struct {
+	err string
+}
+
+func (err errHSMNotPresent) Error() string {
+	return err.err
+}
+
+type yubiSlot struct {
+	role   data.RoleName
+	slotID []byte
+}
+
+// YubiPrivateKey represents a private key inside of a yubikey
+type YubiPrivateKey struct {
+	data.ECDSAPublicKey
+	passRetriever notary.PassRetriever
+	slot          []byte
+	libLoader     pkcs11LibLoader
+}
+
+// yubikeySigner wraps a YubiPrivateKey and implements the crypto.Signer interface
+type yubikeySigner struct {
+	YubiPrivateKey
+}
+
+// NewYubiPrivateKey returns a YubiPrivateKey, which implements the data.PrivateKey
+// interface except that the private material is inaccessible
+func NewYubiPrivateKey(slot []byte, pubKey data.ECDSAPublicKey,
+	passRetriever notary.PassRetriever) *YubiPrivateKey {
+
+	return &YubiPrivateKey{
+		ECDSAPublicKey: pubKey,
+		passRetriever:  passRetriever,
+		slot:           slot,
+		libLoader:      defaultLoader,
+	}
+}
+
+// Public is a required method of the crypto.Signer interface
+func (ys *yubikeySigner) Public() crypto.PublicKey {
+	publicKey, err := x509.ParsePKIXPublicKey(ys.YubiPrivateKey.Public())
+	if err != nil {
+		return nil
+	}
+
+	return publicKey
+}
+
+func (y *YubiPrivateKey) setLibLoader(loader pkcs11LibLoader) {
+	y.libLoader = loader
+}
+
+// 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
+}
+
+// SignatureAlgorithm returns which algorithm this key uses to sign - currently
+// hardcoded to ECDSA
+func (y YubiPrivateKey) SignatureAlgorithm() data.SigAlgorithm {
+	return data.ECDSASignature
+}
+
+// Sign is a required method of the crypto.Signer interface and the data.PrivateKey
+// interface
+func (y *YubiPrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) ([]byte, error) {
+	ctx, session, err := SetupHSMEnv(pkcs11Lib, y.libLoader)
+	if err != nil {
+		return nil, err
+	}
+	defer cleanup(ctx, session)
+
+	v := signed.Verifiers[data.ECDSASignature]
+	for i := 0; i < sigAttempts; i++ {
+		sig, err := sign(ctx, session, y.slot, y.passRetriever, msg)
+		if err != nil {
+			return nil, fmt.Errorf("failed to sign using Yubikey: %v", err)
+		}
+		if err := v.Verify(&y.ECDSAPublicKey, sig, msg); err == nil {
+			return sig, nil
+		}
+	}
+	return nil, errors.New("failed to generate signature on Yubikey")
+}
+
+// If a byte array is less than the number of bytes specified by
+// ecdsaPrivateKeySize, left-zero-pad the byte array until
+// it is the required size.
+func ensurePrivateKeySize(payload []byte) []byte {
+	final := payload
+	if len(payload) < ecdsaPrivateKeySize {
+		final = make([]byte, ecdsaPrivateKeySize)
+		copy(final[ecdsaPrivateKeySize-len(payload):], payload)
+	}
+	return final
+}
+
+// addECDSAKey adds a key to the yubikey
+func addECDSAKey(
+	ctx IPKCS11Ctx,
+	session pkcs11.SessionHandle,
+	privKey data.PrivateKey,
+	pkcs11KeyID []byte,
+	passRetriever notary.PassRetriever,
+	role data.RoleName,
+) error {
+	logrus.Debugf("Attempting to add key to yubikey with ID: %s", privKey.ID())
+
+	err := login(ctx, session, passRetriever, pkcs11.CKU_SO, SOUserPin)
+	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 := ensurePrivateKeySize(ecdsaPrivKey.D.Bytes())
+
+	// Hard-coded policy: the generated certificate expires in 10 years.
+	startTime := time.Now()
+	template, err := utils.NewCertificate(role.String(), startTime, startTime.AddDate(10, 0, 0))
+	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),
+		pkcs11.NewAttribute(pkcs11.CKA_VENDOR_DEFINED, yubikeyKeymode),
+	}
+
+	_, 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 IPKCS11Ctx, session pkcs11.SessionHandle, pkcs11KeyID []byte) (*data.ECDSAPublicKey, data.RoleName, 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", err.Error())
+		return nil, "", err
+	}
+	obj, _, err := ctx.FindObjects(session, 1)
+	if err != nil {
+		logrus.Debugf("Failed to find objects: %v", err)
+		return nil, "", err
+	}
+	if err := ctx.FindObjectsFinal(session); err != nil {
+		logrus.Debugf("Failed to finalize: %s", 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 ECSAKey
+	attr, err := ctx.GetAttributeValue(session, obj[0], attrTemplate)
+	if err != nil {
+		logrus.Debugf("Failed to get Attribute for: %v", 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
+	}
+
+	return data.NewECDSAPublicKey(pubBytes), data.CanonicalRootRole, nil
+}
+
+// sign returns a signature for a given signature request
+func sign(ctx IPKCS11Ctx, session pkcs11.SessionHandle, pkcs11KeyID []byte, passRetriever notary.PassRetriever, payload []byte) ([]byte, error) {
+	err := login(ctx, session, passRetriever, pkcs11.CKU_USER, UserPin)
+	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 {
+		logrus.Debugf("Failed to init find objects: %s", err.Error())
+		return nil, err
+	}
+	obj, _, err := ctx.FindObjects(session, 1)
+	if err != nil {
+		logrus.Debugf("Failed to find objects: %v", err)
+		return nil, err
+	}
+	if err = ctx.FindObjectsFinal(session); err != nil {
+		logrus.Debugf("Failed to finalize find objects: %s", err.Error())
+		return nil, err
+	}
+	if len(obj) != 1 {
+		return nil, errors.New("length of objects found not 1")
+	}
+
+	var sig []byte
+	err = ctx.SignInit(
+		session, []*pkcs11.Mechanism{pkcs11.NewMechanism(pkcs11.CKM_ECDSA, nil)}, obj[0])
+	if err != nil {
+		return nil, err
+	}
+
+	// Get the SHA256 of the payload
+	digest := sha256.Sum256(payload)
+
+	if (yubikeyKeymode & KeymodeTouch) > 0 {
+		touchToSignUI()
+		defer touchDoneCallback()
+	}
+	// a call to Sign, whether or not Sign fails, will clear the SignInit
+	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 yubiRemoveKey(ctx IPKCS11Ctx, session pkcs11.SessionHandle, pkcs11KeyID []byte, passRetriever notary.PassRetriever, keyID string) error {
+	err := login(ctx, session, passRetriever, pkcs11.CKU_SO, SOUserPin)
+	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.Debugf("Failed to init find objects: %s", err.Error())
+		return err
+	}
+	obj, b, err := ctx.FindObjects(session, 1)
+	if err != nil {
+		logrus.Debugf("Failed to find objects: %s %v", err.Error(), b)
+		return err
+	}
+	if err := ctx.FindObjectsFinal(session); err != nil {
+		logrus.Debugf("Failed to finalize find objects: %s", err.Error())
+		return err
+	}
+	if len(obj) != 1 {
+		logrus.Debugf("should have found exactly one object")
+		return err
+	}
+
+	// Delete the certificate
+	err = ctx.DestroyObject(session, obj[0])
+	if err != nil {
+		logrus.Debugf("Failed to delete cert")
+		return err
+	}
+	return nil
+}
+
+func yubiListKeys(ctx IPKCS11Ctx, session pkcs11.SessionHandle) (keys map[string]yubiSlot, err error) {
+	keys = make(map[string]yubiSlot)
+
+	attrTemplate := []*pkcs11.Attribute{
+		pkcs11.NewAttribute(pkcs11.CKA_ID, []byte{0}),
+		pkcs11.NewAttribute(pkcs11.CKA_VALUE, []byte{0}),
+	}
+
+	objs, err := listObjects(ctx, session)
+	if err != nil {
+		return nil, err
+	}
+
+	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 ECDSA
+		attr, err := ctx.GetAttributeValue(session, obj, attrTemplate)
+		if err != nil {
+			logrus.Debugf("Failed to get Attribute for: %v", 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(data.RoleName(cert.Subject.CommonName)) {
+					continue
+				}
+			}
+		}
+
+		// we found nothing
+		if cert == nil {
+			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:   data.RoleName(cert.Subject.CommonName),
+			slotID: slot,
+		}
+	}
+	return
+}
+
+func listObjects(ctx IPKCS11Ctx, session pkcs11.SessionHandle) ([]pkcs11.ObjectHandle, error) {
+	findTemplate := []*pkcs11.Attribute{
+		pkcs11.NewAttribute(pkcs11.CKA_TOKEN, true),
+		pkcs11.NewAttribute(pkcs11.CKA_CLASS, pkcs11.CKO_CERTIFICATE),
+	}
+
+	if err := ctx.FindObjectsInit(session, findTemplate); err != nil {
+		logrus.Debugf("Failed to init: %s", 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...)
+	}
+	if err != nil {
+		logrus.Debugf("Failed to find: %s %v", err.Error(), b)
+		if len(objs) == 0 {
+			return nil, err
+		}
+	}
+	if err := ctx.FindObjectsFinal(session); err != nil {
+		logrus.Debugf("Failed to finalize: %s", err.Error())
+		return nil, err
+	}
+	return objs, nil
+}
+
+func getNextEmptySlot(ctx IPKCS11Ctx, 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", err.Error())
+		return nil, err
+	}
+	objs, b, err := ctx.FindObjects(session, numSlots)
+	// if there are more objects than `numSlots`, get all of them until
+	// there are no more to get
+	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(map[int]bool)
+	if err != nil {
+		logrus.Debugf("Failed to find: %s %v", 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
+	}
+	for _, obj := range objs {
+		// Retrieve the slot ID
+		attr, err := ctx.GetAttributeValue(session, obj, attrTemplate)
+		if err != nil {
+			continue
+		}
+
+		// Iterate through attributes. If an ID attr was found, mark it as taken
+		for _, a := range attr {
+			if a.Type == pkcs11.CKA_ID {
+				if len(a.Value) < 1 {
+					continue
+				}
+				// a byte will always be capable of representing all slot IDs
+				// for the Yubikeys
+				slotNum := int(a.Value[0])
+				if slotNum >= numSlots {
+					// defensive
+					continue
+				}
+				taken[slotNum] = true
+			}
+		}
+	}
+	// iterate the token locations in our preferred order and use the first
+	// available one. Otherwise exit the loop and return an error.
+	for _, loc := range slotIDs {
+		if !taken[loc] {
+			return []byte{byte(loc)}, nil
+		}
+	}
+	return nil, errors.New("yubikey has no available slots")
+}
+
+// YubiStore is a KeyStore for private keys inside a Yubikey
+type YubiStore struct {
+	passRetriever notary.PassRetriever
+	keys          map[string]yubiSlot
+	backupStore   trustmanager.KeyStore
+	libLoader     pkcs11LibLoader
+}
+
+// NewYubiStore returns a YubiStore, given a backup key store to write any
+// generated keys to (usually a KeyFileStore)
+func NewYubiStore(backupStore trustmanager.KeyStore, passphraseRetriever notary.PassRetriever) (
+	*YubiStore, error) {
+
+	s := &YubiStore{
+		passRetriever: passphraseRetriever,
+		keys:          make(map[string]yubiSlot),
+		backupStore:   backupStore,
+		libLoader:     defaultLoader,
+	}
+	s.ListKeys() // populate keys field
+	return s, nil
+}
+
+// Name returns a user friendly name for the location this store
+// keeps its data
+func (s YubiStore) Name() string {
+	return "yubikey"
+}
+
+func (s *YubiStore) setLibLoader(loader pkcs11LibLoader) {
+	s.libLoader = loader
+}
+
+// ListKeys returns a list of keys in the yubikey store
+func (s *YubiStore) ListKeys() map[string]trustmanager.KeyInfo {
+	if len(s.keys) > 0 {
+		return buildKeyMap(s.keys)
+	}
+	ctx, session, err := SetupHSMEnv(pkcs11Lib, s.libLoader)
+	if err != nil {
+		logrus.Debugf("No yubikey found, using alternative key storage: %s", err.Error())
+		return nil
+	}
+	defer cleanup(ctx, session)
+
+	keys, err := yubiListKeys(ctx, session)
+	if err != nil {
+		logrus.Debugf("Failed to list key from the yubikey: %s", err.Error())
+		return nil
+	}
+	s.keys = keys
+
+	return buildKeyMap(keys)
+}
+
+// AddKey puts a key inside the Yubikey, as well as writing it to the backup store
+func (s *YubiStore) AddKey(keyInfo trustmanager.KeyInfo, privKey data.PrivateKey) error {
+	added, err := s.addKey(privKey.ID(), keyInfo.Role, privKey)
+	if err != nil {
+		return err
+	}
+	if added && s.backupStore != nil {
+		err = s.backupStore.AddKey(keyInfo, privKey)
+		if err != nil {
+			defer s.RemoveKey(privKey.ID())
+			return ErrBackupFailed{err: err.Error()}
+		}
+	}
+	return nil
+}
+
+// Only add if we haven't seen the key already.  Return whether the key was
+// added.
+func (s *YubiStore) addKey(keyID string, role data.RoleName, privKey data.PrivateKey) (
+	bool, error) {
+
+	// We only allow adding root keys for now
+	if role != data.CanonicalRootRole {
+		return false, fmt.Errorf(
+			"yubikey only supports storing root keys, got %s for key: %s", role, keyID)
+	}
+
+	ctx, session, err := SetupHSMEnv(pkcs11Lib, s.libLoader)
+	if err != nil {
+		logrus.Debugf("No yubikey found, using alternative key storage: %s", err.Error())
+		return false, err
+	}
+	defer cleanup(ctx, session)
+
+	if k, ok := s.keys[keyID]; ok {
+		if k.role == role {
+			// already have the key and it's associated with the correct role
+			return false, nil
+		}
+	}
+
+	slot, err := getNextEmptySlot(ctx, session)
+	if err != nil {
+		logrus.Debugf("Failed to get an empty yubikey slot: %s", err.Error())
+		return false, err
+	}
+	logrus.Debugf("Attempting to store key using yubikey slot %v", slot)
+
+	err = addECDSAKey(
+		ctx, session, privKey, slot, s.passRetriever, role)
+	if err == nil {
+		s.keys[privKey.ID()] = yubiSlot{
+			role:   role,
+			slotID: slot,
+		}
+		return true, nil
+	}
+	logrus.Debugf("Failed to add key to yubikey: %v", err)
+
+	return false, err
+}
+
+// GetKey retrieves a key from the Yubikey only (it does not look inside the
+// backup store)
+func (s *YubiStore) GetKey(keyID string) (data.PrivateKey, data.RoleName, error) {
+	ctx, session, err := SetupHSMEnv(pkcs11Lib, s.libLoader)
+	if err != nil {
+		logrus.Debugf("No yubikey found, using alternative key storage: %s", err.Error())
+		if _, ok := err.(errHSMNotPresent); ok {
+			err = trustmanager.ErrKeyNotFound{KeyID: keyID}
+		}
+		return nil, "", err
+	}
+	defer cleanup(ctx, session)
+
+	key, ok := s.keys[keyID]
+	if !ok {
+		return nil, "", trustmanager.ErrKeyNotFound{KeyID: keyID}
+	}
+
+	pubKey, alias, err := getECDSAKey(ctx, session, key.slotID)
+	if err != nil {
+		logrus.Debugf("Failed to get key from slot %s: %s", key.slotID, err.Error())
+		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", 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
+}
+
+// RemoveKey deletes a key from the Yubikey only (it does not remove it from the
+// backup store)
+func (s *YubiStore) RemoveKey(keyID string) error {
+	ctx, session, err := SetupHSMEnv(pkcs11Lib, s.libLoader)
+	if err != nil {
+		logrus.Debugf("No yubikey found, using alternative key storage: %s", err.Error())
+		return nil
+	}
+	defer cleanup(ctx, session)
+
+	key, ok := s.keys[keyID]
+	if !ok {
+		return errors.New("Key not present in yubikey")
+	}
+	err = yubiRemoveKey(ctx, session, key.slotID, s.passRetriever, keyID)
+	if err == nil {
+		delete(s.keys, keyID)
+	} else {
+		logrus.Debugf("Failed to remove from the yubikey KeyID %s: %v", keyID, err)
+	}
+
+	return err
+}
+
+// GetKeyInfo is not yet implemented
+func (s *YubiStore) GetKeyInfo(keyID string) (trustmanager.KeyInfo, error) {
+	return trustmanager.KeyInfo{}, fmt.Errorf("Not yet implemented")
+}
+
+func cleanup(ctx IPKCS11Ctx, session pkcs11.SessionHandle) {
+	err := ctx.CloseSession(session)
+	if err != nil {
+		logrus.Debugf("Error closing session: %s", err.Error())
+	}
+	finalizeAndDestroy(ctx)
+}
+
+func finalizeAndDestroy(ctx IPKCS11Ctx) {
+	err := ctx.Finalize()
+	if err != nil {
+		logrus.Debugf("Error finalizing: %s", err.Error())
+	}
+	ctx.Destroy()
+}
+
+// SetupHSMEnv is a method that depends on the existences
+func SetupHSMEnv(libraryPath string, libLoader pkcs11LibLoader) (
+	IPKCS11Ctx, pkcs11.SessionHandle, error) {
+
+	if libraryPath == "" {
+		return nil, 0, errHSMNotPresent{err: "no library found"}
+	}
+	p := libLoader(libraryPath)
+
+	if p == nil {
+		return nil, 0, fmt.Errorf("failed to load library %s", libraryPath)
+	}
+
+	if err := p.Initialize(); err != nil {
+		defer finalizeAndDestroy(p)
+		return nil, 0, fmt.Errorf("found library %s, but initialize error %s", libraryPath, err.Error())
+	}
+
+	slots, err := p.GetSlotList(true)
+	if err != nil {
+		defer finalizeAndDestroy(p)
+		return nil, 0, fmt.Errorf(
+			"loaded library %s, but failed to list HSM slots %s", libraryPath, err)
+	}
+	// Check to see if we got any slots from the HSM.
+	if len(slots) < 1 {
+		defer finalizeAndDestroy(p)
+		return nil, 0, fmt.Errorf(
+			"loaded library %s, but no HSM slots found", libraryPath)
+	}
+
+	// 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 {
+		defer cleanup(p, session)
+		return nil, 0, fmt.Errorf(
+			"loaded library %s, but failed to start session with HSM %s",
+			libraryPath, err)
+	}
+
+	logrus.Debugf("Initialized PKCS11 library %s and started HSM session", libraryPath)
+	return p, session, nil
+}
+
+// IsAccessible returns true if a Yubikey can be accessed
+func IsAccessible() bool {
+	if pkcs11Lib == "" {
+		return false
+	}
+	ctx, session, err := SetupHSMEnv(pkcs11Lib, defaultLoader)
+	if err != nil {
+		return false
+	}
+	defer cleanup(ctx, session)
+	return true
+}
+
+func login(ctx IPKCS11Ctx, session pkcs11.SessionHandle, passRetriever notary.PassRetriever, 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{}
+		}
+
+		// attempt to login. Loop if failed
+		err = ctx.Login(session, userFlag, passwd)
+		if err == nil {
+			return nil
+		}
+	}
+}
+
+func buildKeyMap(keys map[string]yubiSlot) map[string]trustmanager.KeyInfo {
+	res := make(map[string]trustmanager.KeyInfo)
+	for k, v := range keys {
+		res[k] = trustmanager.KeyInfo{Role: v.role, Gun: ""}
+	}
+	return res
+}