cc-backend/auth/auth.go
2022-03-03 14:54:37 +01:00

420 lines
11 KiB
Go

package auth
import (
"context"
"crypto/ed25519"
"crypto/rand"
"database/sql"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"net/http"
"os"
"strings"
"time"
"github.com/ClusterCockpit/cc-backend/log"
sq "github.com/Masterminds/squirrel"
"github.com/golang-jwt/jwt/v4"
"github.com/gorilla/sessions"
"github.com/jmoiron/sqlx"
"golang.org/x/crypto/bcrypt"
)
// Only Username and Roles will always be filled in when returned by `GetUser`.
// If Name and Email is needed as well, use auth.FetchUser(), which does a database
// query for all fields.
type User struct {
Username string `json:"username"`
Password string `json:"-"`
Name string `json:"name"`
Roles []string `json:"roles"`
ViaLdap bool `json:"via-ldap"`
Email string `json:"email"`
}
const (
RoleAdmin string = "admin"
RoleApi string = "api"
RoleUser string = "user"
)
func (u *User) HasRole(role string) bool {
for _, r := range u.Roles {
if r == role {
return true
}
}
return false
}
type ContextKey string
const ContextUserKey ContextKey = "user"
type Authentication struct {
db *sqlx.DB
sessionStore *sessions.CookieStore
jwtPublicKey ed25519.PublicKey
jwtPrivateKey ed25519.PrivateKey
ldapConfig *LdapConfig
ldapSyncUserPassword string
// If zero, tokens/sessions do not expire.
SessionMaxAge time.Duration
JwtMaxAge time.Duration
}
func (auth *Authentication) Init(db *sqlx.DB, ldapConfig *LdapConfig) error {
auth.db = db
_, err := db.Exec(`
CREATE TABLE IF NOT EXISTS user (
username varchar(255) PRIMARY KEY,
password varchar(255) DEFAULT NULL,
ldap tinyint DEFAULT 0,
name varchar(255) DEFAULT NULL,
roles varchar(255) DEFAULT NULL,
email varchar(255) DEFAULT NULL);`)
if err != nil {
return err
}
sessKey := os.Getenv("SESSION_KEY")
if sessKey == "" {
log.Warn("environment variable 'SESSION_KEY' not set (will use non-persistent random key)")
bytes := make([]byte, 32)
if _, err := rand.Read(bytes); err != nil {
return err
}
auth.sessionStore = sessions.NewCookieStore(bytes)
} else {
bytes, err := base64.StdEncoding.DecodeString(sessKey)
if err != nil {
return err
}
auth.sessionStore = sessions.NewCookieStore(bytes)
}
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
}
auth.jwtPublicKey = ed25519.PublicKey(bytes)
bytes, err = base64.StdEncoding.DecodeString(privKey)
if err != nil {
return err
}
auth.jwtPrivateKey = ed25519.PrivateKey(bytes)
}
if ldapConfig != nil {
auth.ldapConfig = ldapConfig
if err := auth.initLdap(); err != nil {
return err
}
}
return nil
}
// arg must be formated like this: "<username>:[admin|api|]:<password>"
func (auth *Authentication) AddUser(arg string) error {
parts := strings.SplitN(arg, ":", 3)
if len(parts) != 3 || len(parts[0]) == 0 {
return errors.New("invalid argument format")
}
roles := strings.Split(parts[1], ",")
return auth.CreateUser(parts[0], "", parts[2], "", roles)
}
func (auth *Authentication) CreateUser(username, name, password, email string, roles []string) error {
for _, role := range roles {
if role != RoleAdmin && role != RoleApi && role != RoleUser {
return fmt.Errorf("invalid user role: %#v", role)
}
}
if username == "" {
return errors.New("username should not be empty")
}
if password != "" {
bytes, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
if err != nil {
return err
}
password = string(bytes)
}
rolesJson, _ := json.Marshal(roles)
cols := []string{"username", "password", "roles"}
vals := []interface{}{username, password, string(rolesJson)}
if name != "" {
cols = append(cols, "name")
vals = append(vals, name)
}
if email != "" {
cols = append(cols, "email")
vals = append(vals, email)
}
if _, err := sq.Insert("user").Columns(cols...).Values(vals...).RunWith(auth.db).Exec(); err != nil {
return err
}
log.Infof("new user %#v created (roles: %s)", username, roles)
return nil
}
func (auth *Authentication) DelUser(username string) error {
_, err := auth.db.Exec(`DELETE FROM user WHERE user.username = ?`, username)
return err
}
func (auth *Authentication) FetchUsers(viaLdap bool) ([]*User, error) {
q := sq.Select("username", "name", "email", "roles").From("user")
if !viaLdap {
q = q.Where("ldap = 0")
} else {
q = q.Where("ldap = 1")
}
rows, err := q.RunWith(auth.db).Query()
if err != nil {
return nil, err
}
users := make([]*User, 0)
defer rows.Close()
for rows.Next() {
rawroles := ""
user := &User{}
var name, email sql.NullString
if err := rows.Scan(&user.Username, &name, &email, &rawroles); err != nil {
return nil, err
}
if err := json.Unmarshal([]byte(rawroles), &user.Roles); err != nil {
return nil, err
}
user.Name = name.String
user.Email = email.String
users = append(users, user)
}
return users, nil
}
func (auth *Authentication) FetchUser(username string) (*User, error) {
user := &User{Username: username}
var hashedPassword, name, rawRoles, email sql.NullString
if err := sq.Select("password", "ldap", "name", "roles", "email").From("user").
Where("user.username = ?", username).RunWith(auth.db).
QueryRow().Scan(&hashedPassword, &user.ViaLdap, &name, &rawRoles, &email); err != nil {
return nil, fmt.Errorf("user '%s' not found (%s)", username, err.Error())
}
user.Password = hashedPassword.String
user.Name = name.String
user.Email = email.String
if rawRoles.Valid {
if err := json.Unmarshal([]byte(rawRoles.String), &user.Roles); err != nil {
return nil, err
}
}
return user, nil
}
// Handle a POST request that should log the user in, starting a new session.
func (auth *Authentication) Login(onsuccess http.Handler, onfailure func(rw http.ResponseWriter, r *http.Request, loginErr error)) http.Handler {
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
username, password := r.FormValue("username"), r.FormValue("password")
user, err := auth.FetchUser(username)
if err == nil && user.ViaLdap && auth.ldapConfig != nil {
err = auth.loginViaLdap(user, password)
} else if err == nil && !user.ViaLdap && user.Password != "" {
if e := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password)); e != nil {
err = fmt.Errorf("user '%s' provided the wrong password (%s)", username, e.Error())
}
} else {
err = errors.New("could not authenticate user")
}
if err != nil {
log.Warnf("login of user %#v failed: %s", username, err.Error())
onfailure(rw, r, err)
return
}
session, err := auth.sessionStore.New(r, "session")
if err != nil {
log.Errorf("session creation failed: %s", err.Error())
http.Error(rw, err.Error(), http.StatusInternalServerError)
return
}
if auth.SessionMaxAge != 0 {
session.Options.MaxAge = int(auth.SessionMaxAge.Seconds())
}
session.Values["username"] = user.Username
session.Values["roles"] = user.Roles
if err := auth.sessionStore.Save(r, rw, session); err != nil {
log.Errorf("session save failed: %s", err.Error())
http.Error(rw, err.Error(), http.StatusInternalServerError)
return
}
log.Infof("login successfull: user: %#v (roles: %v)", user.Username, user.Roles)
ctx := context.WithValue(r.Context(), ContextUserKey, user)
onsuccess.ServeHTTP(rw, r.WithContext(ctx))
})
}
var ErrTokenInvalid error = errors.New("invalid token")
func (auth *Authentication) authViaToken(r *http.Request) (*User, error) {
if auth.jwtPublicKey == nil {
return nil, nil
}
rawtoken := r.Header.Get("X-Auth-Token")
if rawtoken == "" {
rawtoken = r.Header.Get("Authorization")
prefix := "Bearer "
if !strings.HasPrefix(rawtoken, prefix) {
return nil, nil
}
rawtoken = rawtoken[len(prefix):]
}
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 auth.jwtPublicKey, 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)
}
}
}
// TODO: Check if sub is still a valid user!
return &User{
Username: sub,
Roles: roles,
}, nil
}
// Authenticate the user and put a User object in the
// context of the request. If authentication fails,
// do not continue but send client to the login screen.
func (auth *Authentication) Auth(onsuccess http.Handler, onfailure func(rw http.ResponseWriter, r *http.Request, authErr error)) http.Handler {
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
user, err := auth.authViaToken(r)
if err != nil {
log.Warnf("authentication failed: %s", err.Error())
http.Error(rw, err.Error(), http.StatusUnauthorized)
return
}
if user != nil {
// Successfull authentication using a token
ctx := context.WithValue(r.Context(), ContextUserKey, user)
onsuccess.ServeHTTP(rw, r.WithContext(ctx))
return
}
session, err := auth.sessionStore.Get(r, "session")
if err != nil {
// sessionStore.Get will return a new session if no current one is attached to this request.
http.Error(rw, err.Error(), http.StatusInternalServerError)
return
}
if session.IsNew {
log.Warn("authentication failed: no session or jwt found")
onfailure(rw, r, errors.New("no valid session or JWT provided"))
return
}
username, _ := session.Values["username"].(string)
roles, _ := session.Values["roles"].([]string)
ctx := context.WithValue(r.Context(), ContextUserKey, &User{
Username: username,
Roles: roles,
})
onsuccess.ServeHTTP(rw, r.WithContext(ctx))
})
}
// Generate a new JWT that can be used for authentication
func (auth *Authentication) ProvideJWT(user *User) (string, error) {
if auth.jwtPrivateKey == nil {
return "", errors.New("environment variable 'JWT_PRIVATE_KEY' not set")
}
claims := jwt.MapClaims{
"sub": user.Username,
"roles": user.Roles,
}
if auth.JwtMaxAge != 0 {
claims["exp"] = time.Now().Add(auth.JwtMaxAge).Unix()
}
tok := jwt.NewWithClaims(jwt.SigningMethodEdDSA, claims)
return tok.SignedString(auth.jwtPrivateKey)
}
func GetUser(ctx context.Context) *User {
x := ctx.Value(ContextUserKey)
if x == nil {
return nil
}
return x.(*User)
}
// Clears the session cookie
func (auth *Authentication) Logout(onsuccess http.Handler) http.Handler {
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
session, err := auth.sessionStore.Get(r, "session")
if err != nil {
http.Error(rw, err.Error(), http.StatusInternalServerError)
return
}
if !session.IsNew {
session.Options.MaxAge = -1
if err := auth.sessionStore.Save(r, rw, session); err != nil {
http.Error(rw, err.Error(), http.StatusInternalServerError)
return
}
}
onsuccess.ServeHTTP(rw, r)
})
}