Add glide.yaml and vendor deps

vendor/github.com/docker/distribution/registry/handlers/hmac.go

@@ -0,0 +1,74 @@
+package handlers
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"time"
+)
+
+// blobUploadState captures the state serializable state of the blob upload.
+type blobUploadState struct {
+	// name is the primary repository under which the blob will be linked.
+	Name string
+
+	// UUID identifies the upload.
+	UUID string
+
+	// offset contains the current progress of the upload.
+	Offset int64
+
+	// StartedAt is the original start time of the upload.
+	StartedAt time.Time
+}
+
+type hmacKey string
+
+var errInvalidSecret = fmt.Errorf("invalid secret")
+
+// unpackUploadState unpacks and validates the blob upload state from the
+// token, using the hmacKey secret.
+func (secret hmacKey) unpackUploadState(token string) (blobUploadState, error) {
+	var state blobUploadState
+
+	tokenBytes, err := base64.URLEncoding.DecodeString(token)
+	if err != nil {
+		return state, err
+	}
+	mac := hmac.New(sha256.New, []byte(secret))
+
+	if len(tokenBytes) < mac.Size() {
+		return state, errInvalidSecret
+	}
+
+	macBytes := tokenBytes[:mac.Size()]
+	messageBytes := tokenBytes[mac.Size():]
+
+	mac.Write(messageBytes)
+	if !hmac.Equal(mac.Sum(nil), macBytes) {
+		return state, errInvalidSecret
+	}
+
+	if err := json.Unmarshal(messageBytes, &state); err != nil {
+		return state, err
+	}
+
+	return state, nil
+}
+
+// packUploadState packs the upload state signed with and hmac digest using
+// the hmacKey secret, encoding to url safe base64. The resulting token can be
+// used to share data with minimized risk of external tampering.
+func (secret hmacKey) packUploadState(lus blobUploadState) (string, error) {
+	mac := hmac.New(sha256.New, []byte(secret))
+	p, err := json.Marshal(lus)
+	if err != nil {
+		return "", err
+	}
+
+	mac.Write(p)
+
+	return base64.URLEncoding.EncodeToString(append(mac.Sum(nil), p...)), nil
+}