Go语言如何使用golang-jwt/jwt/v4进行JWT鉴权详解

{
  "alg": "HS256",
  "typ": "JWT"
}

{
  "sub": "1234567890",
  "name": "John Doe",
  "admin": true
}

HMACSHA256(
  base64UrlEncode(header) + "." +
  base64UrlEncode(payload),
  secret)

go install "github.com/golang-jwt/jwt/v4"

type MyClaims struct {
	Phone string `json:"phone"`
	jwt.RegisteredClaims  // 注意!这是jwt-go的v4版本新增的，原先是jwt.StandardClaims
}

var MySecret = []byte("手写的从前") // 定义secret，后面会用到

// 这里传入的是手机号，因为我项目登陆用的是手机号和密码
func MakeToken(phone string) (tokenString string, err error) {
	claim := MyClaims{
		Phone: phone,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(3 * time.Hour * time.Duration(1))), // 过期时间3小时
			IssuedAt:  jwt.NewNumericDate(time.Now()),     // 签发时间
			NotBefore: jwt.NewNumericDate(time.Now()),     // 生效时间
		}}
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claim) // 使用HS256算法
	tokenString, err = token.SignedString(MySecret)
	return tokenString, err
}

func Secret() jwt.Keyfunc {
	return func(token *jwt.Token) (interface{}, error) {
		return []byte("手写的从前"), nil  // 这是我的secret
	}
}

func ParseToken(tokenss string) (*MyClaims, error) {
	token, err := jwt.ParseWithClaims(tokenss, &MyClaims{}, Secret())
	if err != nil {
		if ve, ok := err.(*jwt.ValidationError); ok {
			if ve.Errors&jwt.ValidationErrorMalformed != 0 {
				return nil, errors.New("that's not even a token")
			} else if ve.Errors&jwt.ValidationErrorExpired != 0 {
				return nil, errors.New("token is expired")
			} else if ve.Errors&jwt.ValidationErrorNotValidYet != 0 {
				return nil, errors.New("token not active yet")
			} else {
				return nil, errors.New("couldn't handle this token")
			}
		}
	}
	if claims, ok := token.Claims.(*MyClaims); ok && token.Valid {
		return claims, nil
	}
	return nil, errors.New("couldn't handle this token")
}