add core/error/util files

pkg/core/token_claims.go

@@ -0,0 +1,19 @@
+package core
+
+import (
+	"github.com/dgrijalva/jwt-go"
+)
+
+type TokenType byte
+
+const (
+	USER_TOKEN_TYPE_NORMAL      TokenType = 1
+	USER_TOKEN_TYPE_REQUIRE_2FA TokenType = 2
+)
+
+type UserTokenClaims struct {
+	UserTokenId string    `json:"userTokenId"`
+	Username    string    `json:"username,omitempty"`
+	Type        TokenType `json:"type"`
+	jwt.StandardClaims
+}