cc-backend/internal/auth/jwt.go

202 lines
5.0 KiB
Go

// Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
// All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package auth
import (
"crypto/ed25519"
"database/sql"
"encoding/base64"
"errors"
"fmt"
"net/http"
"os"
"strings"
"time"
"github.com/ClusterCockpit/cc-backend/pkg/log"
"github.com/golang-jwt/jwt/v4"
)
type JWTAuthConfig struct {
// Specifies for how long a session or JWT shall be valid
// as a string parsable by time.ParseDuration().
MaxAge int64 `json:"max-age"`
}
type JWTAuthenticator struct {
auth *Authentication
publicKey ed25519.PublicKey
privateKey ed25519.PrivateKey
loginTokenKey []byte // HS256 key
config *JWTAuthConfig
}
var _ Authenticator = (*JWTAuthenticator)(nil)
func (ja *JWTAuthenticator) Init(auth *Authentication, conf interface{}) error {
ja.auth = auth
ja.config = conf.(*JWTAuthConfig)
pubKey, privKey := os.Getenv("JWT_PUBLIC_KEY"), os.Getenv("JWT_PRIVATE_KEY")
if pubKey == "" || privKey == "" {
log.Warn("environment variables 'JWT_PUBLIC_KEY' or 'JWT_PRIVATE_KEY' not set (token based authentication will not work)")
} else {
bytes, err := base64.StdEncoding.DecodeString(pubKey)
if err != nil {
return err
}
ja.publicKey = ed25519.PublicKey(bytes)
bytes, err = base64.StdEncoding.DecodeString(privKey)
if err != nil {
return err
}
ja.privateKey = ed25519.PrivateKey(bytes)
}
if pubKey = os.Getenv("CROSS_LOGIN_JWT_HS512_KEY"); pubKey != "" {
bytes, err := base64.StdEncoding.DecodeString(pubKey)
if err != nil {
return err
}
ja.loginTokenKey = bytes
}
return nil
}
func (ja *JWTAuthenticator) CanLogin(user *User, rw http.ResponseWriter, r *http.Request) bool {
return (user != nil && user.AuthSource == AuthViaToken) || r.Header.Get("Authorization") != "" || r.URL.Query().Get("login-token") != ""
}
func (ja *JWTAuthenticator) Login(user *User, rw http.ResponseWriter, r *http.Request) (*User, error) {
rawtoken := r.Header.Get("X-Auth-Token")
if rawtoken == "" {
rawtoken = r.Header.Get("Authorization")
rawtoken = strings.TrimPrefix(rawtoken, "Bearer ")
if rawtoken == "" {
rawtoken = r.URL.Query().Get("login-token")
}
}
token, err := jwt.Parse(rawtoken, func(t *jwt.Token) (interface{}, error) {
if t.Method == jwt.SigningMethodEdDSA {
return ja.publicKey, nil
}
if t.Method == jwt.SigningMethodHS256 || t.Method == jwt.SigningMethodHS512 {
return ja.loginTokenKey, nil
}
return nil, fmt.Errorf("unkown signing method for login token: %s (known: HS256, HS512, EdDSA)", t.Method.Alg())
})
if err != nil {
return nil, err
}
if err := token.Claims.Valid(); err != nil {
return nil, err
}
claims := token.Claims.(jwt.MapClaims)
sub, _ := claims["sub"].(string)
exp, _ := claims["exp"].(float64)
var roles []string
if rawroles, ok := claims["roles"].([]interface{}); ok {
for _, rr := range rawroles {
if r, ok := rr.(string); ok {
roles = append(roles, r)
}
}
}
if rawrole, ok := claims["roles"].(string); ok {
roles = append(roles, rawrole)
}
if user == nil {
user, err = ja.auth.GetUser(sub)
if err != nil && err != sql.ErrNoRows {
return nil, err
} else if user == nil {
user = &User{
Username: sub,
Roles: roles,
AuthSource: AuthViaToken,
}
if err := ja.auth.AddUser(user); err != nil {
return nil, err
}
}
}
user.Expiration = time.Unix(int64(exp), 0)
return user, nil
}
func (ja *JWTAuthenticator) Auth(rw http.ResponseWriter, r *http.Request) (*User, error) {
rawtoken := r.Header.Get("X-Auth-Token")
if rawtoken == "" {
rawtoken = r.Header.Get("Authorization")
rawtoken = strings.TrimPrefix(rawtoken, "Bearer ")
}
// Because a user can also log in via a token, the
// session cookie must be checked here as well:
if rawtoken == "" {
return ja.auth.AuthViaSession(rw, r)
}
token, err := jwt.Parse(rawtoken, func(t *jwt.Token) (interface{}, error) {
if t.Method != jwt.SigningMethodEdDSA {
return nil, errors.New("only Ed25519/EdDSA supported")
}
return ja.publicKey, nil
})
if err != nil {
return nil, err
}
if err := token.Claims.Valid(); err != nil {
return nil, err
}
claims := token.Claims.(jwt.MapClaims)
sub, _ := claims["sub"].(string)
var roles []string
if rawroles, ok := claims["roles"].([]interface{}); ok {
for _, rr := range rawroles {
if r, ok := rr.(string); ok {
roles = append(roles, r)
}
}
}
return &User{
Username: sub,
Roles: roles,
AuthSource: AuthViaToken,
}, nil
}
// Generate a new JWT that can be used for authentication
func (ja *JWTAuthenticator) ProvideJWT(user *User) (string, error) {
if ja.privateKey == nil {
return "", errors.New("environment variable 'JWT_PRIVATE_KEY' not set")
}
now := time.Now()
claims := jwt.MapClaims{
"sub": user.Username,
"roles": user.Roles,
"iat": now.Unix(),
}
if ja.config != nil && ja.config.MaxAge != 0 {
claims["exp"] = now.Add(time.Duration(ja.config.MaxAge)).Unix()
}
return jwt.NewWithClaims(jwt.SigningMethodEdDSA, claims).SignedString(ja.privateKey)
}