Files
backrest/internal/auth/auth.go
2024-03-23 17:48:10 +00:00

139 lines
3.2 KiB
Go

package auth
import (
"encoding/base64"
"errors"
"fmt"
"time"
v1 "github.com/garethgeorge/backrest/gen/go/v1"
"github.com/garethgeorge/backrest/internal/config"
"github.com/golang-jwt/jwt/v5"
"golang.org/x/crypto/bcrypt"
)
var (
anonymousUser = &v1.User{
Name: "default",
Password: &v1.User_PasswordBcrypt{PasswordBcrypt: "JDJhJDEwJDNCdzJoNFlhaWFZQy9TSDN3ZGxSRHVPZHdzV2lsNmtBSHdFSmtIWHk1dS8wYjZuUWJrMGFx"}, // default password is "password"
}
defaultUsers = []*v1.User{
anonymousUser,
}
)
type Authenticator struct {
config config.ConfigStore
key []byte
}
func NewAuthenticator(key []byte, config config.ConfigStore) *Authenticator {
return &Authenticator{
config: config,
key: key,
}
}
var ErrUserNotFound = errors.New("user not found")
var ErrInvalidPassword = errors.New("invalid password")
func (a *Authenticator) Login(username, password string) (*v1.User, error) {
config, err := a.config.Get()
if err != nil {
return nil, fmt.Errorf("get config: %w", err)
}
auth := config.GetAuth()
if auth.GetDisabled() {
return nil, errors.New("authentication is disabled")
}
for _, user := range auth.GetUsers() {
if user.Name != username {
continue
}
if err := checkPassword(user, password); err != nil {
return nil, err
}
return user, nil
}
return nil, ErrUserNotFound
}
func (a *Authenticator) VerifyJWT(token string) (*v1.User, error) {
config, err := a.config.Get()
if err != nil {
return nil, fmt.Errorf("get config: %w", err)
}
auth := config.GetAuth()
if auth == nil {
return nil, fmt.Errorf("auth config not set")
}
t, err := jwt.Parse(token, func(t *jwt.Token) (interface{}, error) {
return a.key, nil
})
if err != nil {
return nil, fmt.Errorf("parse token: %w", err)
}
if !t.Valid {
return nil, fmt.Errorf("invalid token")
}
subject, err := t.Claims.GetSubject()
if err != nil {
return nil, fmt.Errorf("get subject: %w", err)
}
for _, user := range auth.GetUsers() {
if user.Name == subject {
return user, nil
}
}
return nil, ErrUserNotFound
}
func (a *Authenticator) CreateJWT(user *v1.User) (string, error) {
claims := &jwt.RegisteredClaims{
ExpiresAt: jwt.NewNumericDate(time.Now().Add(7 * 24 * time.Hour)),
Subject: user.Name,
}
t := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
s, err := t.SignedString(a.key)
if err != nil {
return "", fmt.Errorf("sign token: %w", err)
}
return s, nil
}
// checkPassword returns nil if the password is correct, or an error if it is not.
func checkPassword(user *v1.User, password string) error {
switch pw := user.Password.(type) {
case *v1.User_PasswordBcrypt:
pwHash, err := base64.StdEncoding.DecodeString(pw.PasswordBcrypt)
if err != nil {
return fmt.Errorf("decode password: %w", err)
}
if err := bcrypt.CompareHashAndPassword(pwHash, []byte(password)); err != nil {
return fmt.Errorf("%w: %w", ErrInvalidPassword, err)
}
default:
return fmt.Errorf("unsupported password type: %T", pw)
}
return nil
}
func CreatePassword(password string) (string, error) {
hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
if err != nil {
return "", fmt.Errorf("generate password: %w", err)
}
return base64.StdEncoding.EncodeToString(hash), nil
}