Files
remark42/app/rest/auth/jwt.go
T
2018-05-22 00:03:03 -05:00

141 lines
3.8 KiB
Go

package auth
import (
"net/http"
"time"
jwt "github.com/dgrijalva/jwt-go"
"github.com/pkg/errors"
"github.com/umputun/remark/app/store"
)
// JWT wraps jwt operations
// supports both header and cookie jwt
type JWT struct {
secret string
secureCookies bool
exp time.Duration
}
// CustomClaims stores user info for auth and state & from from login
type CustomClaims struct {
jwt.StandardClaims
User *store.User `json:"user,omitempty"`
// state and from used for oauth handshake
State string `json:"state,omitempty"`
From string `json:"from,omitempty"`
}
const jwtCookieName = "JWT"
const jwtHeaderKey = "X-JWT"
const xsrfCookieName = "XSRF-TOKEN"
const xsrfHeaderKey = "X-XSRF-TOKEN"
// NewJWT makes JWT service
func NewJWT(secret string, secureCookies bool, exp time.Duration) *JWT {
res := JWT{
secret: secret,
secureCookies: secureCookies,
exp: exp,
}
return &res
}
// Set creates jwt cookie with xsrf cookie and put it to ResponseWriter
// accepts claims and sets expiration if none defined
func (j *JWT) Set(w http.ResponseWriter, claims *CustomClaims) error {
if claims.ExpiresAt == 0 {
claims.ExpiresAt = time.Now().Add(j.exp).Unix()
}
token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
tokenString, err := token.SignedString([]byte(j.secret))
if err != nil {
return errors.Wrap(err, "can't sign jwt token")
}
cookieExpiration := 365 * 24 * 3600 // 1 year
jwtCookie := http.Cookie{Name: jwtCookieName, Value: tokenString, HttpOnly: true, Path: "/",
MaxAge: cookieExpiration, Secure: j.secureCookies}
http.SetCookie(w, &jwtCookie)
xsrfCookie := http.Cookie{Name: xsrfCookieName, Value: claims.Id, HttpOnly: false, Path: "/",
MaxAge: cookieExpiration, Secure: j.secureCookies}
http.SetCookie(w, &xsrfCookie)
return nil
}
// Get jwt from header or cookie
// if cookie used, verify xsrf token to match
func (j *JWT) Get(r *http.Request) (*CustomClaims, error) {
fromCookie := false
tokenString := ""
if tokenHeader := r.Header.Get(jwtHeaderKey); tokenHeader != "" {
tokenString = tokenHeader
}
if tokenString == "" {
fromCookie = true
jc, err := r.Cookie(jwtCookieName)
if err != nil {
return nil, errors.Wrap(err, "jwt cookie was not presented")
}
tokenString = jc.Value
}
token, err := jwt.ParseWithClaims(tokenString, &CustomClaims{}, func(token *jwt.Token) (interface{}, error) {
if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
return nil, errors.Errorf("unexpected signing method: %v", token.Header["alg"])
}
return []byte(j.secret), nil
})
if err != nil {
return nil, errors.Wrap(err, "can't parse jwt")
}
claims, ok := token.Claims.(*CustomClaims)
if !ok || !token.Valid {
return nil, errors.New("invalid jwt")
}
if fromCookie && claims.User != nil {
xsrf := r.Header.Get(xsrfHeaderKey)
if claims.Id != xsrf {
return nil, errors.New("xsrf mismatch")
}
}
return claims, nil
}
// Refresh gets jwt from request, checks if it will be expiring soon (1/2 of expiration) and create the new onw
func (j *JWT) Refresh(w http.ResponseWriter, r *http.Request) (*CustomClaims, error) {
claims, err := j.Get(r)
if err != nil {
return nil, err
}
untilExp := claims.ExpiresAt - time.Now().Unix()
if untilExp <= int64(j.exp.Seconds()/2) {
claims.ExpiresAt = time.Now().Add(j.exp).Unix()
e := j.Set(w, claims)
return claims, e
}
return claims, nil
}
// Reset token's cookies
func (j *JWT) Reset(w http.ResponseWriter) {
jwtCookie := http.Cookie{Name: jwtCookieName, Value: "", HttpOnly: false, Path: "/",
MaxAge: -1, Expires: time.Unix(0, 0), Secure: j.secureCookies}
http.SetCookie(w, &jwtCookie)
xsrfCookie := http.Cookie{Name: xsrfCookieName, Value: "", HttpOnly: false, Path: "/",
MaxAge: -1, Expires: time.Unix(0, 0), Secure: j.secureCookies}
http.SetCookie(w, &xsrfCookie)
}