filebrowser/http/auth.go

148 lines
3.2 KiB
Go

package http
import (
"encoding/json"
"net/http"
"strings"
"time"
jwt "github.com/dgrijalva/jwt-go"
"github.com/dgrijalva/jwt-go/request"
fm "github.com/hacdias/filemanager"
)
// authHandler proccesses the authentication for the user.
func authHandler(c *fm.Context, w http.ResponseWriter, r *http.Request) (int, error) {
// NoAuth instances shouldn't call this method.
if c.NoAuth {
return 0, nil
}
// Receive the credentials from the request and unmarshal them.
var cred fm.User
if r.Body == nil {
return http.StatusForbidden, nil
}
err := json.NewDecoder(r.Body).Decode(&cred)
if err != nil {
return http.StatusForbidden, nil
}
// Checks if the user exists.
u, err := c.Store.Users.GetByUsername(cred.Username, c.NewFS)
if err != nil {
return http.StatusForbidden, nil
}
// Checks if the password is correct.
if !fm.CheckPasswordHash(cred.Password, u.Password) {
return http.StatusForbidden, nil
}
c.User = u
return printToken(c, w)
}
// renewAuthHandler is used when the front-end already has a JWT token
// and is checking if it is up to date. If so, updates its info.
func renewAuthHandler(c *fm.Context, w http.ResponseWriter, r *http.Request) (int, error) {
ok, u := validateAuth(c, r)
if !ok {
return http.StatusForbidden, nil
}
c.User = u
return printToken(c, w)
}
// claims is the JWT claims.
type claims struct {
fm.User
NoAuth bool `json:"noAuth"`
jwt.StandardClaims
}
// printToken prints the final JWT token to the user.
func printToken(c *fm.Context, w http.ResponseWriter) (int, error) {
// Creates a copy of the user and removes it password
// hash so it never arrives to the user.
u := fm.User{}
u = *c.User
u.Password = ""
// Builds the claims.
claims := claims{
u,
c.NoAuth,
jwt.StandardClaims{
ExpiresAt: time.Now().Add(time.Hour * 24).Unix(),
Issuer: "File Manager",
},
}
// Creates the token and signs it.
token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
signed, err := token.SignedString(c.Key)
if err != nil {
return http.StatusInternalServerError, err
}
// Writes the token.
w.Header().Set("Content-Type", "cty")
w.Write([]byte(signed))
return 0, nil
}
type extractor []string
func (e extractor) ExtractToken(r *http.Request) (string, error) {
token, _ := request.AuthorizationHeaderExtractor.ExtractToken(r)
// Checks if the token isn't empty and if it contains two dots.
// The former prevents incompatibility with URLs that previously
// used basic auth.
if token != "" && strings.Count(token, ".") == 2 {
return token, nil
}
cookie, err := r.Cookie("auth")
if err != nil {
return "", request.ErrNoTokenInRequest
}
return cookie.Value, nil
}
// validateAuth is used to validate the authentication and returns the
// User if it is valid.
func validateAuth(c *fm.Context, r *http.Request) (bool, *fm.User) {
if c.NoAuth {
c.User = c.DefaultUser
return true, c.User
}
keyFunc := func(token *jwt.Token) (interface{}, error) {
return c.Key, nil
}
var claims claims
token, err := request.ParseFromRequestWithClaims(r,
extractor{},
&claims,
keyFunc,
)
if err != nil || !token.Valid {
return false, nil
}
u, err := c.Store.Users.Get(claims.User.ID, c.NewFS)
if err != nil {
return false, nil
}
c.User = u
return true, u
}