added claims type

jwt.go

@@ -323,7 +323,7 @@ type Token struct {
 	signature    string
 	rawSignature []byte
 	header       map[string]interface{}
-	Claims       map[string]interface{}
+	Claims       Claims
 }
 
 // String returns the tokens encoded string
@@ -352,14 +352,18 @@ func (t *Token) Data() string {
 }
 
 // NewToken returns a new *Token using the provided hash algorithm and claims
-// If h is nil HS256 will be used
-func NewToken(claims map[string]interface{}, h Hash) *Token {
-	if h == nil {
-		h = NewHS256()
+// If claims is nil, an empty map is used
+// If hash is nil, HS256 is used
+func NewToken(claims Claims, hash Hash) *Token {
+	if claims == nil {
+		claims = make(Claims)
+	}
+	if hash == nil {
+		hash = NewHS256()
 	}
 	return &Token{
 		header: map[string]interface{}{
-			"alg": h.Alg(),
+			"alg": hash.Alg(),
 			"typ": typ,
 		},
 		Claims: claims,