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// Copyright 2015 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package v2auth implements etcd authentication.
package v2auth
import (
"context"
"encoding/json"
"fmt"
"net/http"
"path"
"reflect"
"sort"
"strings"
"time"
"go.etcd.io/etcd/etcdserver"
"go.etcd.io/etcd/etcdserver/api/v2error"
"go.etcd.io/etcd/etcdserver/etcdserverpb"
"go.etcd.io/etcd/pkg/types"
"github.com/coreos/pkg/capnslog"
"go.uber.org/zap"
"golang.org/x/crypto/bcrypt"
)
const (
// StorePermsPrefix is the internal prefix of the storage layer dedicated to storing user data.
StorePermsPrefix = "/2"
// RootRoleName is the name of the ROOT role, with privileges to manage the cluster.
RootRoleName = "root"
// GuestRoleName is the name of the role that defines the privileges of an unauthenticated user.
GuestRoleName = "guest"
)
var (
plog = capnslog.NewPackageLogger("go.etcd.io/etcd/v3", "etcdserver/auth")
)
var rootRole = Role{
Role: RootRoleName,
Permissions: Permissions{
KV: RWPermission{
Read: []string{"/*"},
Write: []string{"/*"},
},
},
}
var guestRole = Role{
Role: GuestRoleName,
Permissions: Permissions{
KV: RWPermission{
Read: []string{"/*"},
Write: []string{"/*"},
},
},
}
type doer interface {
Do(context.Context, etcdserverpb.Request) (etcdserver.Response, error)
}
type Store interface {
AllUsers() ([]string, error)
GetUser(name string) (User, error)
CreateOrUpdateUser(user User) (out User, created bool, err error)
CreateUser(user User) (User, error)
DeleteUser(name string) error
UpdateUser(user User) (User, error)
AllRoles() ([]string, error)
GetRole(name string) (Role, error)
CreateRole(role Role) error
DeleteRole(name string) error
UpdateRole(role Role) (Role, error)
AuthEnabled() bool
EnableAuth() error
DisableAuth() error
PasswordStore
}
type PasswordStore interface {
CheckPassword(user User, password string) bool
HashPassword(password string) (string, error)
}
type store struct {
lg *zap.Logger
server doer
timeout time.Duration
ensuredOnce bool
PasswordStore
}
type User struct {
User string `json:"user"`
Password string `json:"password,omitempty"`
Roles []string `json:"roles"`
Grant []string `json:"grant,omitempty"`
Revoke []string `json:"revoke,omitempty"`
}
type Role struct {
Role string `json:"role"`
Permissions Permissions `json:"permissions"`
Grant *Permissions `json:"grant,omitempty"`
Revoke *Permissions `json:"revoke,omitempty"`
}
type Permissions struct {
KV RWPermission `json:"kv"`
}
func (p *Permissions) IsEmpty() bool {
return p == nil || (len(p.KV.Read) == 0 && len(p.KV.Write) == 0)
}
type RWPermission struct {
Read []string `json:"read"`
Write []string `json:"write"`
}
type Error struct {
Status int
Errmsg string
}
func (ae Error) Error() string { return ae.Errmsg }
func (ae Error) HTTPStatus() int { return ae.Status }
func authErr(hs int, s string, v ...interface{}) Error {
return Error{Status: hs, Errmsg: fmt.Sprintf("auth: "+s, v...)}
}
func NewStore(lg *zap.Logger, server doer, timeout time.Duration) Store {
s := &store{
lg: lg,
server: server,
timeout: timeout,
PasswordStore: passwordStore{},
}
return s
}
// passwordStore implements PasswordStore using bcrypt to hash user passwords
type passwordStore struct{}
func (passwordStore) CheckPassword(user User, password string) bool {
err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password))
return err == nil
}
func (passwordStore) HashPassword(password string) (string, error) {
hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
return string(hash), err
}
func (s *store) AllUsers() ([]string, error) {
resp, err := s.requestResource("/users/", false)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return []string{}, nil
}
}
return nil, err
}
var nodes []string
for _, n := range resp.Event.Node.Nodes {
_, user := path.Split(n.Key)
nodes = append(nodes, user)
}
sort.Strings(nodes)
return nodes, nil
}
func (s *store) GetUser(name string) (User, error) { return s.getUser(name, false) }
// CreateOrUpdateUser should be only used for creating the new user or when you are not
// sure if it is a create or update. (When only password is passed in, we are not sure
// if it is a update or create)
func (s *store) CreateOrUpdateUser(user User) (out User, created bool, err error) {
_, err = s.getUser(user.User, true)
if err == nil {
out, err = s.UpdateUser(user)
return out, false, err
}
u, err := s.CreateUser(user)
return u, true, err
}
func (s *store) CreateUser(user User) (User, error) {
// Attach root role to root user.
if user.User == "root" {
user = attachRootRole(user)
}
u, err := s.createUserInternal(user)
if err == nil {
if s.lg != nil {
s.lg.Info("created a user", zap.String("user-name", user.User))
} else {
plog.Noticef("created user %s", user.User)
}
}
return u, err
}
func (s *store) createUserInternal(user User) (User, error) {
if user.Password == "" {
return user, authErr(http.StatusBadRequest, "Cannot create user %s with an empty password", user.User)
}
hash, err := s.HashPassword(user.Password)
if err != nil {
return user, err
}
user.Password = hash
_, err = s.createResource("/users/"+user.User, user)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeNodeExist {
return user, authErr(http.StatusConflict, "User %s already exists.", user.User)
}
}
}
return user, err
}
func (s *store) DeleteUser(name string) error {
if s.AuthEnabled() && name == "root" {
return authErr(http.StatusForbidden, "Cannot delete root user while auth is enabled.")
}
err := s.deleteResource("/users/" + name)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return authErr(http.StatusNotFound, "User %s does not exist", name)
}
}
return err
}
if s.lg != nil {
s.lg.Info("deleted a user", zap.String("user-name", name))
} else {
plog.Noticef("deleted user %s", name)
}
return nil
}
func (s *store) UpdateUser(user User) (User, error) {
old, err := s.getUser(user.User, true)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return user, authErr(http.StatusNotFound, "User %s doesn't exist.", user.User)
}
}
return old, err
}
newUser, err := old.merge(s.lg, user, s.PasswordStore)
if err != nil {
return old, err
}
if reflect.DeepEqual(old, newUser) {
return old, authErr(http.StatusBadRequest, "User not updated. Use grant/revoke/password to update the user.")
}
_, err = s.updateResource("/users/"+user.User, newUser)
if err == nil {
if s.lg != nil {
s.lg.Info("updated a user", zap.String("user-name", user.User))
} else {
plog.Noticef("updated user %s", user.User)
}
}
return newUser, err
}
func (s *store) AllRoles() ([]string, error) {
nodes := []string{RootRoleName}
resp, err := s.requestResource("/roles/", false)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return nodes, nil
}
}
return nil, err
}
for _, n := range resp.Event.Node.Nodes {
_, role := path.Split(n.Key)
nodes = append(nodes, role)
}
sort.Strings(nodes)
return nodes, nil
}
func (s *store) GetRole(name string) (Role, error) { return s.getRole(name, false) }
func (s *store) CreateRole(role Role) error {
if role.Role == RootRoleName {
return authErr(http.StatusForbidden, "Cannot modify role %s: is root role.", role.Role)
}
_, err := s.createResource("/roles/"+role.Role, role)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeNodeExist {
return authErr(http.StatusConflict, "Role %s already exists.", role.Role)
}
}
}
if err == nil {
if s.lg != nil {
s.lg.Info("created a new role", zap.String("role-name", role.Role))
} else {
plog.Noticef("created new role %s", role.Role)
}
}
return err
}
func (s *store) DeleteRole(name string) error {
if name == RootRoleName {
return authErr(http.StatusForbidden, "Cannot modify role %s: is root role.", name)
}
err := s.deleteResource("/roles/" + name)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return authErr(http.StatusNotFound, "Role %s doesn't exist.", name)
}
}
}
if err == nil {
if s.lg != nil {
s.lg.Info("delete a new role", zap.String("role-name", name))
} else {
plog.Noticef("deleted role %s", name)
}
}
return err
}
func (s *store) UpdateRole(role Role) (Role, error) {
if role.Role == RootRoleName {
return Role{}, authErr(http.StatusForbidden, "Cannot modify role %s: is root role.", role.Role)
}
old, err := s.getRole(role.Role, true)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return role, authErr(http.StatusNotFound, "Role %s doesn't exist.", role.Role)
}
}
return old, err
}
newRole, err := old.merge(s.lg, role)
if err != nil {
return old, err
}
if reflect.DeepEqual(old, newRole) {
return old, authErr(http.StatusBadRequest, "Role not updated. Use grant/revoke to update the role.")
}
_, err = s.updateResource("/roles/"+role.Role, newRole)
if err == nil {
if s.lg != nil {
s.lg.Info("updated a new role", zap.String("role-name", role.Role))
} else {
plog.Noticef("updated role %s", role.Role)
}
}
return newRole, err
}
func (s *store) AuthEnabled() bool {
return s.detectAuth()
}
func (s *store) EnableAuth() error {
if s.AuthEnabled() {
return authErr(http.StatusConflict, "already enabled")
}
if _, err := s.getUser("root", true); err != nil {
return authErr(http.StatusConflict, "No root user available, please create one")
}
if _, err := s.getRole(GuestRoleName, true); err != nil {
if s.lg != nil {
s.lg.Info(
"no guest role access found; creating default",
zap.String("role-name", GuestRoleName),
)
} else {
plog.Printf("no guest role access found, creating default")
}
if err := s.CreateRole(guestRole); err != nil {
if s.lg != nil {
s.lg.Warn(
"failed to create a guest role; aborting auth enable",
zap.String("role-name", GuestRoleName),
zap.Error(err),
)
} else {
plog.Errorf("error creating guest role. aborting auth enable.")
}
return err
}
}
if err := s.enableAuth(); err != nil {
if s.lg != nil {
s.lg.Warn("failed to enable auth", zap.Error(err))
} else {
plog.Errorf("error enabling auth (%v)", err)
}
return err
}
if s.lg != nil {
s.lg.Info("enabled auth")
} else {
plog.Noticef("auth: enabled auth")
}
return nil
}
func (s *store) DisableAuth() error {
if !s.AuthEnabled() {
return authErr(http.StatusConflict, "already disabled")
}
err := s.disableAuth()
if err == nil {
if s.lg != nil {
s.lg.Info("disabled auth")
} else {
plog.Noticef("auth: disabled auth")
}
} else {
if s.lg != nil {
s.lg.Warn("failed to disable auth", zap.Error(err))
} else {
plog.Errorf("error disabling auth (%v)", err)
}
}
return err
}
// merge applies the properties of the passed-in User to the User on which it
// is called and returns a new User with these modifications applied. Think of
// all Users as immutable sets of data. Merge allows you to perform the set
// operations (desired grants and revokes) atomically
func (ou User) merge(lg *zap.Logger, nu User, s PasswordStore) (User, error) {
var out User
if ou.User != nu.User {
return out, authErr(http.StatusConflict, "Merging user data with conflicting usernames: %s %s", ou.User, nu.User)
}
out.User = ou.User
if nu.Password != "" {
hash, err := s.HashPassword(nu.Password)
if err != nil {
return ou, err
}
out.Password = hash
} else {
out.Password = ou.Password
}
currentRoles := types.NewUnsafeSet(ou.Roles...)
for _, g := range nu.Grant {
if currentRoles.Contains(g) {
if lg != nil {
lg.Warn(
"attempted to grant a duplicate role for a user",
zap.String("user-name", nu.User),
zap.String("role-name", g),
)
} else {
plog.Noticef("granting duplicate role %s for user %s", g, nu.User)
}
return User{}, authErr(http.StatusConflict, fmt.Sprintf("Granting duplicate role %s for user %s", g, nu.User))
}
currentRoles.Add(g)
}
for _, r := range nu.Revoke {
if !currentRoles.Contains(r) {
if lg != nil {
lg.Warn(
"attempted to revoke a ungranted role for a user",
zap.String("user-name", nu.User),
zap.String("role-name", r),
)
} else {
plog.Noticef("revoking ungranted role %s for user %s", r, nu.User)
}
return User{}, authErr(http.StatusConflict, fmt.Sprintf("Revoking ungranted role %s for user %s", r, nu.User))
}
currentRoles.Remove(r)
}
out.Roles = currentRoles.Values()
sort.Strings(out.Roles)
return out, nil
}
// merge for a role works the same as User above -- atomic Role application to
// each of the substructures.
func (r Role) merge(lg *zap.Logger, n Role) (Role, error) {
var out Role
var err error
if r.Role != n.Role {
return out, authErr(http.StatusConflict, "Merging role with conflicting names: %s %s", r.Role, n.Role)
}
out.Role = r.Role
out.Permissions, err = r.Permissions.Grant(n.Grant)
if err != nil {
return out, err
}
out.Permissions, err = out.Permissions.Revoke(lg, n.Revoke)
return out, err
}
func (r Role) HasKeyAccess(key string, write bool) bool {
if r.Role == RootRoleName {
return true
}
return r.Permissions.KV.HasAccess(key, write)
}
func (r Role) HasRecursiveAccess(key string, write bool) bool {
if r.Role == RootRoleName {
return true
}
return r.Permissions.KV.HasRecursiveAccess(key, write)
}
// Grant adds a set of permissions to the permission object on which it is called,
// returning a new permission object.
func (p Permissions) Grant(n *Permissions) (Permissions, error) {
var out Permissions
var err error
if n == nil {
return p, nil
}
out.KV, err = p.KV.Grant(n.KV)
return out, err
}
// Revoke removes a set of permissions to the permission object on which it is called,
// returning a new permission object.
func (p Permissions) Revoke(lg *zap.Logger, n *Permissions) (Permissions, error) {
var out Permissions
var err error
if n == nil {
return p, nil
}
out.KV, err = p.KV.Revoke(lg, n.KV)
return out, err
}
// Grant adds a set of permissions to the permission object on which it is called,
// returning a new permission object.
func (rw RWPermission) Grant(n RWPermission) (RWPermission, error) {
var out RWPermission
currentRead := types.NewUnsafeSet(rw.Read...)
for _, r := range n.Read {
if currentRead.Contains(r) {
return out, authErr(http.StatusConflict, "Granting duplicate read permission %s", r)
}
currentRead.Add(r)
}
currentWrite := types.NewUnsafeSet(rw.Write...)
for _, w := range n.Write {
if currentWrite.Contains(w) {
return out, authErr(http.StatusConflict, "Granting duplicate write permission %s", w)
}
currentWrite.Add(w)
}
out.Read = currentRead.Values()
out.Write = currentWrite.Values()
sort.Strings(out.Read)
sort.Strings(out.Write)
return out, nil
}
// Revoke removes a set of permissions to the permission object on which it is called,
// returning a new permission object.
func (rw RWPermission) Revoke(lg *zap.Logger, n RWPermission) (RWPermission, error) {
var out RWPermission
currentRead := types.NewUnsafeSet(rw.Read...)
for _, r := range n.Read {
if !currentRead.Contains(r) {
if lg != nil {
lg.Info(
"revoking ungranted read permission",
zap.String("read-permission", r),
)
} else {
plog.Noticef("revoking ungranted read permission %s", r)
}
continue
}
currentRead.Remove(r)
}
currentWrite := types.NewUnsafeSet(rw.Write...)
for _, w := range n.Write {
if !currentWrite.Contains(w) {
if lg != nil {
lg.Info(
"revoking ungranted write permission",
zap.String("write-permission", w),
)
} else {
plog.Noticef("revoking ungranted write permission %s", w)
}
continue
}
currentWrite.Remove(w)
}
out.Read = currentRead.Values()
out.Write = currentWrite.Values()
sort.Strings(out.Read)
sort.Strings(out.Write)
return out, nil
}
func (rw RWPermission) HasAccess(key string, write bool) bool {
var list []string
if write {
list = rw.Write
} else {
list = rw.Read
}
for _, pat := range list {
match, err := simpleMatch(pat, key)
if err == nil && match {
return true
}
}
return false
}
func (rw RWPermission) HasRecursiveAccess(key string, write bool) bool {
list := rw.Read
if write {
list = rw.Write
}
for _, pat := range list {
match, err := prefixMatch(pat, key)
if err == nil && match {
return true
}
}
return false
}
func simpleMatch(pattern string, key string) (match bool, err error) {
if pattern[len(pattern)-1] == '*' {
return strings.HasPrefix(key, pattern[:len(pattern)-1]), nil
}
return key == pattern, nil
}
func prefixMatch(pattern string, key string) (match bool, err error) {
if pattern[len(pattern)-1] != '*' {
return false, nil
}
return strings.HasPrefix(key, pattern[:len(pattern)-1]), nil
}
func attachRootRole(u User) User {
inRoles := false
for _, r := range u.Roles {
if r == RootRoleName {
inRoles = true
break
}
}
if !inRoles {
u.Roles = append(u.Roles, RootRoleName)
}
return u
}
func (s *store) getUser(name string, quorum bool) (User, error) {
resp, err := s.requestResource("/users/"+name, quorum)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return User{}, authErr(http.StatusNotFound, "User %s does not exist.", name)
}
}
return User{}, err
}
var u User
err = json.Unmarshal([]byte(*resp.Event.Node.Value), &u)
if err != nil {
return u, err
}
// Attach root role to root user.
if u.User == "root" {
u = attachRootRole(u)
}
return u, nil
}
func (s *store) getRole(name string, quorum bool) (Role, error) {
if name == RootRoleName {
return rootRole, nil
}
resp, err := s.requestResource("/roles/"+name, quorum)
if err != nil {
if e, ok := err.(*v2error.Error); ok {
if e.ErrorCode == v2error.EcodeKeyNotFound {
return Role{}, authErr(http.StatusNotFound, "Role %s does not exist.", name)
}
}
return Role{}, err
}
var r Role
err = json.Unmarshal([]byte(*resp.Event.Node.Value), &r)
return r, err
}