Move auth package under registry package

Signed-off-by: Stephen J Day <stephen.day@docker.com>

docs/auth/token/util.go

@@ -0,0 +1,58 @@
+package token
+
+import (
+	"encoding/base64"
+	"errors"
+	"strings"
+)
+
+// joseBase64UrlEncode encodes the given data using the standard base64 url
+// encoding format but with all trailing '=' characters ommitted in accordance
+// with the jose specification.
+// http://tools.ietf.org/html/draft-ietf-jose-json-web-signature-31#section-2
+func joseBase64UrlEncode(b []byte) string {
+	return strings.TrimRight(base64.URLEncoding.EncodeToString(b), "=")
+}
+
+// joseBase64UrlDecode decodes the given string using the standard base64 url
+// decoder but first adds the appropriate number of trailing '=' characters in
+// accordance with the jose specification.
+// http://tools.ietf.org/html/draft-ietf-jose-json-web-signature-31#section-2
+func joseBase64UrlDecode(s string) ([]byte, error) {
+	switch len(s) % 4 {
+	case 0:
+	case 2:
+		s += "=="
+	case 3:
+		s += "="
+	default:
+		return nil, errors.New("illegal base64url string")
+	}
+	return base64.URLEncoding.DecodeString(s)
+}
+
+// actionSet is a special type of stringSet.
+type actionSet struct {
+	stringSet
+}
+
+func newActionSet(actions ...string) actionSet {
+	return actionSet{newStringSet(actions...)}
+}
+
+// Contains calls StringSet.Contains() for
+// either "*" or the given action string.
+func (s actionSet) contains(action string) bool {
+	return s.stringSet.contains("*") || s.stringSet.contains(action)
+}
+
+// contains returns true if q is found in ss.
+func contains(ss []string, q string) bool {
+	for _, s := range ss {
+		if s == q {
+			return true
+		}
+	}
+
+	return false
+}