From c40b86bcde6f16e61449e19cc9da38db5fab7202 Mon Sep 17 00:00:00 2001
From: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Date: Fri, 17 Mar 2017 16:04:56 +0900
Subject: [PATCH] auth, etcdserver: forbid invalid auth management

If auth is enabled,
1. deleting the user root
2. revoking the role root from the user root
must not be allowed. This commit forbids them.
---
 auth/store.go                          | 16 ++++++++++++++++
 etcdserver/api/v3rpc/rpctypes/error.go |  3 +++
 etcdserver/api/v3rpc/util.go           |  2 ++
 3 files changed, 21 insertions(+)

diff --git a/auth/store.go b/auth/store.go
index 55b6cfe24..ac5b344c6 100644
--- a/auth/store.go
+++ b/auth/store.go
@@ -61,6 +61,7 @@ var (
 	ErrAuthOldRevision      = errors.New("auth: revision in header is old")
 	ErrInvalidAuthToken     = errors.New("auth: invalid auth token")
 	ErrInvalidAuthOpts      = errors.New("auth: invalid auth options")
+	ErrInvalidAuthMgmt      = errors.New("auth: invalid auth management")
 
 	// BcryptCost is the algorithm cost / strength for hashing auth passwords
 	BcryptCost = bcrypt.DefaultCost
@@ -352,6 +353,11 @@ func (as *authStore) UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse,
 }
 
 func (as *authStore) UserDelete(r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error) {
+	if as.enabled && strings.Compare(r.Name, rootUser) == 0 {
+		plog.Errorf("the user root must not be deleted")
+		return nil, ErrInvalidAuthMgmt
+	}
+
 	tx := as.be.BatchTx()
 	tx.Lock()
 	defer tx.Unlock()
@@ -477,6 +483,11 @@ func (as *authStore) UserList(r *pb.AuthUserListRequest) (*pb.AuthUserListRespon
 }
 
 func (as *authStore) UserRevokeRole(r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error) {
+	if as.enabled && strings.Compare(r.Name, rootUser) == 0 && strings.Compare(r.Role, rootRole) == 0 {
+		plog.Errorf("the role root must not be revoked from the user root")
+		return nil, ErrInvalidAuthMgmt
+	}
+
 	tx := as.be.BatchTx()
 	tx.Lock()
 	defer tx.Unlock()
@@ -579,6 +590,11 @@ func (as *authStore) RoleRevokePermission(r *pb.AuthRoleRevokePermissionRequest)
 }
 
 func (as *authStore) RoleDelete(r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error) {
+	if as.enabled && strings.Compare(r.Role, rootRole) == 0 {
+		plog.Errorf("the role root must not be deleted")
+		return nil, ErrInvalidAuthMgmt
+	}
+
 	tx := as.be.BatchTx()
 	tx.Lock()
 	defer tx.Unlock()
diff --git a/etcdserver/api/v3rpc/rpctypes/error.go b/etcdserver/api/v3rpc/rpctypes/error.go
index 0ac594051..0907e902c 100644
--- a/etcdserver/api/v3rpc/rpctypes/error.go
+++ b/etcdserver/api/v3rpc/rpctypes/error.go
@@ -56,6 +56,7 @@ var (
 	ErrGRPCPermissionNotGranted = grpc.Errorf(codes.FailedPrecondition, "etcdserver: permission is not granted to the role")
 	ErrGRPCAuthNotEnabled       = grpc.Errorf(codes.FailedPrecondition, "etcdserver: authentication is not enabled")
 	ErrGRPCInvalidAuthToken     = grpc.Errorf(codes.Unauthenticated, "etcdserver: invalid auth token")
+	ErrGRPCInvalidAuthMgmt      = grpc.Errorf(codes.InvalidArgument, "etcdserver: invalid auth management")
 
 	ErrGRPCNoLeader                   = grpc.Errorf(codes.Unavailable, "etcdserver: no leader")
 	ErrGRPCNotCapable                 = grpc.Errorf(codes.Unavailable, "etcdserver: not capable")
@@ -102,6 +103,7 @@ var (
 		grpc.ErrorDesc(ErrGRPCPermissionNotGranted): ErrGRPCPermissionNotGranted,
 		grpc.ErrorDesc(ErrGRPCAuthNotEnabled):       ErrGRPCAuthNotEnabled,
 		grpc.ErrorDesc(ErrGRPCInvalidAuthToken):     ErrGRPCInvalidAuthToken,
+		grpc.ErrorDesc(ErrGRPCInvalidAuthMgmt):      ErrGRPCInvalidAuthMgmt,
 
 		grpc.ErrorDesc(ErrGRPCNoLeader):                   ErrGRPCNoLeader,
 		grpc.ErrorDesc(ErrGRPCNotCapable):                 ErrGRPCNotCapable,
@@ -148,6 +150,7 @@ var (
 	ErrPermissionNotGranted = Error(ErrGRPCPermissionNotGranted)
 	ErrAuthNotEnabled       = Error(ErrGRPCAuthNotEnabled)
 	ErrInvalidAuthToken     = Error(ErrGRPCInvalidAuthToken)
+	ErrInvalidAuthMgmt      = Error(ErrGRPCInvalidAuthMgmt)
 
 	ErrNoLeader                   = Error(ErrGRPCNoLeader)
 	ErrNotCapable                 = Error(ErrGRPCNotCapable)
diff --git a/etcdserver/api/v3rpc/util.go b/etcdserver/api/v3rpc/util.go
index 733bb72e6..cb514a2dc 100644
--- a/etcdserver/api/v3rpc/util.go
+++ b/etcdserver/api/v3rpc/util.go
@@ -97,6 +97,8 @@ func togRPCError(err error) error {
 		return rpctypes.ErrGRPCAuthNotEnabled
 	case auth.ErrInvalidAuthToken:
 		return rpctypes.ErrGRPCInvalidAuthToken
+	case auth.ErrInvalidAuthMgmt:
+		return rpctypes.ErrGRPCInvalidAuthMgmt
 	default:
 		return grpc.Errorf(codes.Unknown, err.Error())
 	}