diff --git a/unum/vendor/github.com/docker/libtrust/key_files.go b/unum/vendor/github.com/docker/libtrust/key_files.go
new file mode 100644
index 0000000..c526de5
--- /dev/null
+++ b/unum/vendor/github.com/docker/libtrust/key_files.go
@@ -0,0 +1,255 @@
+package libtrust
+
+import (
+	"encoding/json"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+var (
+	// ErrKeyFileDoesNotExist indicates that the private key file does not exist.
+	ErrKeyFileDoesNotExist = errors.New("key file does not exist")
+)
+
+func readKeyFileBytes(filename string) ([]byte, error) {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		if os.IsNotExist(err) {
+			err = ErrKeyFileDoesNotExist
+		} else {
+			err = fmt.Errorf("unable to read key file %s: %s", filename, err)
+		}
+
+		return nil, err
+	}
+
+	return data, nil
+}
+
+/*
+	Loading and Saving of Public and Private Keys in either PEM or JWK format.
+*/
+
+// LoadKeyFile opens the given filename and attempts to read a Private Key
+// encoded in either PEM or JWK format (if .json or .jwk file extension).
+func LoadKeyFile(filename string) (PrivateKey, error) {
+	contents, err := readKeyFileBytes(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	var key PrivateKey
+
+	if strings.HasSuffix(filename, ".json") || strings.HasSuffix(filename, ".jwk") {
+		key, err = UnmarshalPrivateKeyJWK(contents)
+		if err != nil {
+			return nil, fmt.Errorf("unable to decode private key JWK: %s", err)
+		}
+	} else {
+		key, err = UnmarshalPrivateKeyPEM(contents)
+		if err != nil {
+			return nil, fmt.Errorf("unable to decode private key PEM: %s", err)
+		}
+	}
+
+	return key, nil
+}
+
+// LoadPublicKeyFile opens the given filename and attempts to read a Public Key
+// encoded in either PEM or JWK format (if .json or .jwk file extension).
+func LoadPublicKeyFile(filename string) (PublicKey, error) {
+	contents, err := readKeyFileBytes(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	var key PublicKey
+
+	if strings.HasSuffix(filename, ".json") || strings.HasSuffix(filename, ".jwk") {
+		key, err = UnmarshalPublicKeyJWK(contents)
+		if err != nil {
+			return nil, fmt.Errorf("unable to decode public key JWK: %s", err)
+		}
+	} else {
+		key, err = UnmarshalPublicKeyPEM(contents)
+		if err != nil {
+			return nil, fmt.Errorf("unable to decode public key PEM: %s", err)
+		}
+	}
+
+	return key, nil
+}
+
+// SaveKey saves the given key to a file using the provided filename.
+// This process will overwrite any existing file at the provided location.
+func SaveKey(filename string, key PrivateKey) error {
+	var encodedKey []byte
+	var err error
+
+	if strings.HasSuffix(filename, ".json") || strings.HasSuffix(filename, ".jwk") {
+		// Encode in JSON Web Key format.
+		encodedKey, err = json.MarshalIndent(key, "", "    ")
+		if err != nil {
+			return fmt.Errorf("unable to encode private key JWK: %s", err)
+		}
+	} else {
+		// Encode in PEM format.
+		pemBlock, err := key.PEMBlock()
+		if err != nil {
+			return fmt.Errorf("unable to encode private key PEM: %s", err)
+		}
+		encodedKey = pem.EncodeToMemory(pemBlock)
+	}
+
+	err = ioutil.WriteFile(filename, encodedKey, os.FileMode(0600))
+	if err != nil {
+		return fmt.Errorf("unable to write private key file %s: %s", filename, err)
+	}
+
+	return nil
+}
+
+// SavePublicKey saves the given public key to the file.
+func SavePublicKey(filename string, key PublicKey) error {
+	var encodedKey []byte
+	var err error
+
+	if strings.HasSuffix(filename, ".json") || strings.HasSuffix(filename, ".jwk") {
+		// Encode in JSON Web Key format.
+		encodedKey, err = json.MarshalIndent(key, "", "    ")
+		if err != nil {
+			return fmt.Errorf("unable to encode public key JWK: %s", err)
+		}
+	} else {
+		// Encode in PEM format.
+		pemBlock, err := key.PEMBlock()
+		if err != nil {
+			return fmt.Errorf("unable to encode public key PEM: %s", err)
+		}
+		encodedKey = pem.EncodeToMemory(pemBlock)
+	}
+
+	err = ioutil.WriteFile(filename, encodedKey, os.FileMode(0644))
+	if err != nil {
+		return fmt.Errorf("unable to write public key file %s: %s", filename, err)
+	}
+
+	return nil
+}
+
+// Public Key Set files
+
+type jwkSet struct {
+	Keys []json.RawMessage `json:"keys"`
+}
+
+// LoadKeySetFile loads a key set
+func LoadKeySetFile(filename string) ([]PublicKey, error) {
+	if strings.HasSuffix(filename, ".json") || strings.HasSuffix(filename, ".jwk") {
+		return loadJSONKeySetFile(filename)
+	}
+
+	// Must be a PEM format file
+	return loadPEMKeySetFile(filename)
+}
+
+func loadJSONKeySetRaw(data []byte) ([]json.RawMessage, error) {
+	if len(data) == 0 {
+		// This is okay, just return an empty slice.
+		return []json.RawMessage{}, nil
+	}
+
+	keySet := jwkSet{}
+
+	err := json.Unmarshal(data, &keySet)
+	if err != nil {
+		return nil, fmt.Errorf("unable to decode JSON Web Key Set: %s", err)
+	}
+
+	return keySet.Keys, nil
+}
+
+func loadJSONKeySetFile(filename string) ([]PublicKey, error) {
+	contents, err := readKeyFileBytes(filename)
+	if err != nil && err != ErrKeyFileDoesNotExist {
+		return nil, err
+	}
+
+	return UnmarshalPublicKeyJWKSet(contents)
+}
+
+func loadPEMKeySetFile(filename string) ([]PublicKey, error) {
+	data, err := readKeyFileBytes(filename)
+	if err != nil && err != ErrKeyFileDoesNotExist {
+		return nil, err
+	}
+
+	return UnmarshalPublicKeyPEMBundle(data)
+}
+
+// AddKeySetFile adds a key to a key set
+func AddKeySetFile(filename string, key PublicKey) error {
+	if strings.HasSuffix(filename, ".json") || strings.HasSuffix(filename, ".jwk") {
+		return addKeySetJSONFile(filename, key)
+	}
+
+	// Must be a PEM format file
+	return addKeySetPEMFile(filename, key)
+}
+
+func addKeySetJSONFile(filename string, key PublicKey) error {
+	encodedKey, err := json.Marshal(key)
+	if err != nil {
+		return fmt.Errorf("unable to encode trusted client key: %s", err)
+	}
+
+	contents, err := readKeyFileBytes(filename)
+	if err != nil && err != ErrKeyFileDoesNotExist {
+		return err
+	}
+
+	rawEntries, err := loadJSONKeySetRaw(contents)
+	if err != nil {
+		return err
+	}
+
+	rawEntries = append(rawEntries, json.RawMessage(encodedKey))
+	entriesWrapper := jwkSet{Keys: rawEntries}
+
+	encodedEntries, err := json.MarshalIndent(entriesWrapper, "", "    ")
+	if err != nil {
+		return fmt.Errorf("unable to encode trusted client keys: %s", err)
+	}
+
+	err = ioutil.WriteFile(filename, encodedEntries, os.FileMode(0644))
+	if err != nil {
+		return fmt.Errorf("unable to write trusted client keys file %s: %s", filename, err)
+	}
+
+	return nil
+}
+
+func addKeySetPEMFile(filename string, key PublicKey) error {
+	// Encode to PEM, open file for appending, write PEM.
+	file, err := os.OpenFile(filename, os.O_CREATE|os.O_APPEND|os.O_RDWR, os.FileMode(0644))
+	if err != nil {
+		return fmt.Errorf("unable to open trusted client keys file %s: %s", filename, err)
+	}
+	defer file.Close()
+
+	pemBlock, err := key.PEMBlock()
+	if err != nil {
+		return fmt.Errorf("unable to encoded trusted key: %s", err)
+	}
+
+	_, err = file.Write(pem.EncodeToMemory(pemBlock))
+	if err != nil {
+		return fmt.Errorf("unable to write trusted keys file: %s", err)
+	}
+
+	return nil
+}