add jwt creating and parsing

internal/jwt/signer_HS256.go

@@ -0,0 +1,20 @@
+package jwt
+
+import "github.com/golang-jwt/jwt/v5"
+
+type HMACSigner struct {
+	secret []byte
+}
+
+func NewHMACSigner(secret []byte) *HMACSigner {
+	return &HMACSigner{secret: secret}
+}
+
+func (s *HMACSigner) Sign(claims jwt.Claims) (string, error) {
+	t := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return t.SignedString(s.secret)
+}
+
+func (s *HMACSigner) Verify(tokenStr string) (jwt.Claims, error) {
+	return parse(tokenStr, jwt.SigningMethodHS256, s.secret)
+}