debian-selinux-policies/policy/modules/ssh.if

## <summary>Secure shell client and server policy.</summary>

#######################################
## <summary>
##	Basic SSH client template.
## </summary>
## <desc>
##	<p>
##	This template creates a derived domains which are used
##	for ssh client sessions.  A derived
##	type is also created to protect the user ssh keys.
##	</p>
##	<p>
##	This template was added for NX.
##	</p>
## </desc>
## <param name="userdomain_prefix">
##	<summary>
##	The prefix of the domain (e.g., user
##	is the prefix for user_t).
##	</summary>
## </param>
## <param name="user_domain">
##	<summary>
##	The type of the domain.
##	</summary>
## </param>
## <param name="user_role">
##	<summary>
##	The role associated with the user domain.
##	</summary>
## </param>
#
template(`ssh_basic_client_template',`

	gen_require(`
		attribute ssh_server;
		type ssh_exec_t, sshd_key_t, sshd_tmp_t;
	')

	##############################
	#
	# Declarations
	#

	type $1_ssh_t;
	application_domain($1_ssh_t, ssh_exec_t)
	role $3 types $1_ssh_t;

	type $1_ssh_home_t;
	files_type($1_ssh_home_t)
	typealias $1_ssh_home_t alias $1_home_ssh_t;

	##############################
	#
	# Client local policy
	#

	allow $1_ssh_t self:capability { setuid setgid dac_override dac_read_search };
	allow $1_ssh_t self:process ~{ ptrace setcurrent setexec setfscreate setrlimit execmem execstack execheap };
	allow $1_ssh_t self:fd use;
	allow $1_ssh_t self:fifo_file rw_fifo_file_perms;
	allow $1_ssh_t self:unix_dgram_socket { create_socket_perms sendto };
	allow $1_ssh_t self:unix_stream_socket { create_stream_socket_perms connectto };
	allow $1_ssh_t self:shm create_shm_perms;
	allow $1_ssh_t self:sem create_sem_perms;
	allow $1_ssh_t self:msgq create_msgq_perms;
	allow $1_ssh_t self:msg { send receive };
	allow $1_ssh_t self:tcp_socket create_stream_socket_perms;

	# for rsync
	allow $1_ssh_t $2:unix_stream_socket rw_socket_perms;
	allow $1_ssh_t $2:unix_stream_socket connectto;

	# Read the ssh key file.
	allow $1_ssh_t sshd_key_t:file read_file_perms;

	# Access the ssh temporary files.
	allow $1_ssh_t sshd_tmp_t:dir manage_dir_perms;
	allow $1_ssh_t sshd_tmp_t:file manage_file_perms;
	files_tmp_filetrans($1_ssh_t, sshd_tmp_t, { file dir })

	# Transition from the domain to the derived domain.
	domtrans_pattern($2, ssh_exec_t, $1_ssh_t)

	# inheriting stream sockets is needed for "ssh host command" as no pty
	# is allocated
	# cjp: should probably fix target to be an attribute for ssh servers
	# or "regular" (not special like sshd_extern_t) servers
	allow $2 ssh_server:unix_stream_socket rw_stream_socket_perms;

	# allow ps to show ssh
	ps_process_pattern($2, $1_ssh_t)

	# user can manage the keys and config
	manage_files_pattern($2, $1_ssh_home_t, $1_ssh_home_t)
	manage_lnk_files_pattern($2, $1_ssh_home_t, $1_ssh_home_t)
	manage_sock_files_pattern($2, $1_ssh_home_t, $1_ssh_home_t)

	# ssh client can manage the keys and config
	manage_files_pattern($1_ssh_t, $1_ssh_home_t, $1_ssh_home_t)
	read_lnk_files_pattern($1_ssh_t, $1_ssh_home_t, $1_ssh_home_t)

	# ssh servers can read the user keys and config
	allow ssh_server $1_ssh_home_t:dir list_dir_perms;
	read_files_pattern(ssh_server, $1_ssh_home_t, $1_ssh_home_t)
	read_lnk_files_pattern(ssh_server, $1_ssh_home_t, $1_ssh_home_t)

	kernel_read_kernel_sysctls($1_ssh_t)
	kernel_read_system_state($1_ssh_t)

	corenet_all_recvfrom_unlabeled($1_ssh_t)
	corenet_all_recvfrom_netlabel($1_ssh_t)
	corenet_tcp_sendrecv_generic_if($1_ssh_t)
	corenet_tcp_sendrecv_generic_node($1_ssh_t)
	corenet_tcp_sendrecv_all_ports($1_ssh_t)
	corenet_tcp_connect_ssh_port($1_ssh_t)
	corenet_sendrecv_ssh_client_packets($1_ssh_t)

	dev_read_urand($1_ssh_t)

	fs_getattr_all_fs($1_ssh_t)
	fs_search_auto_mountpoints($1_ssh_t)

	# run helper programs - needed eg for x11-ssh-askpass
	corecmd_exec_shell($1_ssh_t)
	corecmd_exec_bin($1_ssh_t)

	domain_use_interactive_fds($1_ssh_t)

	files_list_home($1_ssh_t)
	files_read_usr_files($1_ssh_t)
	files_read_etc_runtime_files($1_ssh_t)
	files_read_etc_files($1_ssh_t)
	files_read_var_files($1_ssh_t)

	auth_use_nsswitch($1_ssh_t)

	logging_send_syslog_msg($1_ssh_t)
	logging_read_generic_logs($1_ssh_t)

	miscfiles_read_localization($1_ssh_t)

	seutil_read_config($1_ssh_t)

	optional_policy(`
		kerberos_use($1_ssh_t)
	')
')

#######################################
## <summary>
##	The template to define a ssh server.
## </summary>
## <desc>
##	<p>
##	This template creates a domains to be used for
##	creating a ssh server.  This is typically done
##	to have multiple ssh servers of different sensitivities,
##	such as for an internal network-facing ssh server, and
##	a external network-facing ssh server.
##	</p>
## </desc>
## <param name="userdomain_prefix">
##	<summary>
##	The prefix of the server domain (e.g., sshd
##	is the prefix for sshd_t).
##	</summary>
## </param>
#
template(`ssh_server_template', `
	type $1_t, ssh_server;
	auth_login_pgm_domain($1_t)

	type $1_devpts_t;
	term_login_pty($1_devpts_t)

	type $1_tmpfs_t;
	files_tmpfs_file($1_tmpfs_t)

	type $1_var_run_t;
	files_pid_file($1_var_run_t)

	allow $1_t self:capability { kill sys_chroot sys_nice sys_resource chown dac_override fowner fsetid setgid setuid sys_tty_config };
	allow $1_t self:fifo_file rw_fifo_file_perms;
	allow $1_t self:process { signal getsched setsched setrlimit setexec setkeycreate };
	allow $1_t self:tcp_socket create_stream_socket_perms;
	allow $1_t self:udp_socket create_socket_perms;
	# ssh agent connections:
	allow $1_t self:unix_stream_socket create_stream_socket_perms;
	allow $1_t self:shm create_shm_perms;

	allow $1_t $1_devpts_t:chr_file { rw_chr_file_perms setattr getattr relabelfrom };
	term_create_pty($1_t, $1_devpts_t)

	manage_files_pattern($1_t, $1_tmpfs_t, $1_tmpfs_t)
	fs_tmpfs_filetrans($1_t, $1_tmpfs_t, file)

	allow $1_t $1_var_run_t:dir search_dir_perms;
	allow $1_t $1_var_run_t:file manage_file_perms;
	files_pid_filetrans($1_t, $1_var_run_t, file)

	can_exec($1_t, sshd_exec_t)

	# Access key files
	allow $1_t sshd_key_t:file read_file_perms;

	kernel_read_kernel_sysctls($1_t)
	kernel_read_network_state($1_t)

	corenet_all_recvfrom_unlabeled($1_t)
	corenet_all_recvfrom_netlabel($1_t)
	corenet_tcp_sendrecv_generic_if($1_t)
	corenet_udp_sendrecv_generic_if($1_t)
	corenet_raw_sendrecv_generic_if($1_t)
	corenet_tcp_sendrecv_generic_node($1_t)
	corenet_udp_sendrecv_generic_node($1_t)
	corenet_raw_sendrecv_generic_node($1_t)
	corenet_udp_sendrecv_all_ports($1_t)
	corenet_tcp_sendrecv_all_ports($1_t)
	corenet_tcp_bind_generic_node($1_t)
	corenet_udp_bind_generic_node($1_t)
	corenet_tcp_bind_ssh_port($1_t)
	corenet_tcp_connect_all_ports($1_t)
	corenet_sendrecv_ssh_server_packets($1_t)

	fs_dontaudit_getattr_all_fs($1_t)

	auth_rw_login_records($1_t)
	auth_rw_faillog($1_t)

	corecmd_read_bin_symlinks($1_t)
	corecmd_getattr_bin_files($1_t)
	# for sshd subsystems, such as sftp-server.
	corecmd_getattr_bin_files($1_t)

	domain_interactive_fd($1_t)

	files_read_etc_files($1_t)
	files_read_etc_runtime_files($1_t)
	files_read_usr_files($1_t)

	logging_search_logs($1_t)

	miscfiles_read_localization($1_t)

	userdom_create_all_users_keys($1_t)
	userdom_dontaudit_relabelfrom_user_ptys($1_t)
	userdom_search_user_home_dirs($1_t)

	# Allow checking users mail at login
	optional_policy(`
		mta_getattr_spool($1_t)
	')

	tunable_policy(`use_nfs_home_dirs',`
		fs_read_nfs_files($1_t)
		fs_read_nfs_symlinks($1_t)
	')

	tunable_policy(`use_samba_home_dirs',`
		fs_read_cifs_files($1_t)
	')

	optional_policy(`
		kerberos_use($1_t)
		kerberos_manage_host_rcache($1_t)
	')

	optional_policy(`
		files_read_var_lib_symlinks($1_t)
		nx_spec_domtrans_server($1_t)
	')
')

########################################
## <summary>
##	Role access for ssh
## </summary>
## <param name="role_prefix">
##	<summary>
##	The prefix of the role (e.g., user
##	is the prefix for user_r).
##	</summary>
## </param>
## <param name="role">
##	<summary>
##	Role allowed access
##	</summary>
## </param>
## <param name="domain">
##	<summary>
##	User domain for the role
##	</summary>
## </param>
#
template(`ssh_role_template',`
	gen_require(`
		attribute ssh_server, ssh_agent_type;

		type ssh_t, ssh_exec_t, ssh_tmpfs_t, ssh_home_t;
		type ssh_agent_exec_t, ssh_keysign_t, ssh_tmpfs_t;
		type ssh_agent_tmp_t;
	')

	##############################
	#
	# Declarations
	#

	role $2 types ssh_t;

	type $1_ssh_agent_t, ssh_agent_type;
	userdom_user_application_domain($1_ssh_agent_t, ssh_agent_exec_t)
	domain_interactive_fd($1_ssh_agent_t)
	role $2 types $1_ssh_agent_t;

	##############################
	#
	# Local policy
	#

	# Transition from the domain to the derived domain.
	domtrans_pattern($3, ssh_exec_t, ssh_t)

	# inheriting stream sockets is needed for "ssh host command" as no pty
	# is allocated
	allow $3 ssh_server:unix_stream_socket rw_stream_socket_perms;

	# allow ps to show ssh
	ps_process_pattern($3, ssh_t)
	allow $3 ssh_t:process signal;

	# for rsync
	allow ssh_t $3:unix_stream_socket rw_socket_perms;
	allow ssh_t $3:unix_stream_socket connectto;

	# user can manage the keys and config
	manage_files_pattern($3, ssh_home_t, ssh_home_t)
	manage_lnk_files_pattern($3, ssh_home_t, ssh_home_t)
	manage_sock_files_pattern($3, ssh_home_t, ssh_home_t)
	userdom_search_user_home_dirs($1_t)

	##############################
	#
	# SSH agent local policy
	#

	allow $1_ssh_agent_t self:process { setrlimit signal };
	allow $1_ssh_agent_t self:capability setgid;

	allow $1_ssh_agent_t self:fifo_file rw_file_perms;

	allow $1_ssh_agent_t { $1_ssh_agent_t $3 }:process signull;

	allow $1_ssh_agent_t self:unix_stream_socket { create_stream_socket_perms connectto };

	manage_dirs_pattern($1_ssh_agent_t, ssh_agent_tmp_t, ssh_agent_tmp_t)
	manage_sock_files_pattern($1_ssh_agent_t, ssh_agent_tmp_t, ssh_agent_tmp_t)
	files_tmp_filetrans($1_ssh_agent_t, ssh_agent_tmp_t, { dir sock_file })

	# for ssh-add
	stream_connect_pattern($3, ssh_agent_tmp_t, ssh_agent_tmp_t, $1_ssh_agent_t)

	# Allow the user shell to signal the ssh program.
	allow $3 $1_ssh_agent_t:process signal;

	# allow ps to show ssh
	ps_process_pattern($3, $1_ssh_agent_t)

	domtrans_pattern($3, ssh_agent_exec_t, $1_ssh_agent_t)
	userdom_append_inherited_user_home_content_files($1_ssh_agent_t)

	kernel_read_kernel_sysctls($1_ssh_agent_t)

	dev_read_urand($1_ssh_agent_t)
	dev_read_rand($1_ssh_agent_t)

	fs_search_auto_mountpoints($1_ssh_agent_t)

	# transition back to normal privs upon exec
	corecmd_shell_domtrans($1_ssh_agent_t, $3)
	corecmd_bin_domtrans($1_ssh_agent_t, $3)

	domain_use_interactive_fds($1_ssh_agent_t)

	files_read_etc_files($1_ssh_agent_t)
	files_read_etc_runtime_files($1_ssh_agent_t)
	files_search_home($1_ssh_agent_t)

	libs_read_lib_files($1_ssh_agent_t)

	logging_send_syslog_msg($1_ssh_agent_t)

	miscfiles_read_localization($1_ssh_agent_t)
	miscfiles_read_generic_certs($1_ssh_agent_t)

	seutil_dontaudit_read_config($1_ssh_agent_t)

	# Write to the user domain tty.
	userdom_use_user_terminals($1_ssh_agent_t)

	# for the transition back to normal privs upon exec
	userdom_search_user_home_content($1_ssh_agent_t)
	userdom_user_home_domtrans($1_ssh_agent_t, $3)
	allow $3 $1_ssh_agent_t:fd use;
	allow $3 $1_ssh_agent_t:fifo_file rw_file_perms;
	allow $3 $1_ssh_agent_t:process sigchld;

	tunable_policy(`use_nfs_home_dirs',`
		fs_manage_nfs_files($1_ssh_agent_t)

		# transition back to normal privs upon exec
		fs_nfs_domtrans($1_ssh_agent_t, $3)
	')

	tunable_policy(`use_samba_home_dirs',`
		fs_manage_cifs_files($1_ssh_agent_t)

		# transition back to normal privs upon exec
		fs_cifs_domtrans($1_ssh_agent_t, $3)
	')

	optional_policy(`
		nis_use_ypbind($1_ssh_agent_t)
	')

	optional_policy(`
		tunable_policy(`ssh_use_gpg_agent',`
			# for ssh-add
			gpg_stream_connect_agent($3)
		')
	')

	optional_policy(`
		xserver_use_xdm_fds($1_ssh_agent_t)
		xserver_rw_xdm_pipes($1_ssh_agent_t)
		xdm_sigchld($1_ssh_agent_t)
	')
')

########################################
## <summary>
##	Send a SIGCHLD signal to the ssh server.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_sigchld',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:process sigchld;
')

########################################
## <summary>
##	Send a generic signal to the ssh server.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_signal',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:process signal;
')

########################################
## <summary>
##	Send a null signal to sshd processes.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_signull',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:process signull;
')

########################################
## <summary>
##	Read a ssh server unnamed pipe.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_read_pipes',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:fifo_file { getattr read };
')
########################################
## <summary>
##	Read and write a ssh server unnamed pipe.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_rw_pipes',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:fifo_file { write read getattr ioctl };
')

########################################
## <summary>
##	Read and write ssh server unix domain stream sockets.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_rw_stream_sockets',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:unix_stream_socket rw_stream_socket_perms;
')

########################################
## <summary>
##	Read and write ssh server TCP sockets.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_rw_tcp_sockets',`
	gen_require(`
		type sshd_t;
	')

	allow $1 sshd_t:tcp_socket rw_stream_socket_perms;
')

########################################
## <summary>
##	Do not audit attempts to read and write
##	ssh server TCP sockets.
## </summary>
## <param name="domain">
##	<summary>
##	Domain to not audit.
##	</summary>
## </param>
#
interface(`ssh_dontaudit_rw_tcp_sockets',`
	gen_require(`
		type sshd_t;
	')

	dontaudit $1 sshd_t:tcp_socket { read write };
')

########################################
## <summary>
##	Connect to SSH daemons over TCP sockets.  (Deprecated)
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_tcp_connect',`
	refpolicywarn(`$0($*) has been deprecated.')
')

########################################
## <summary>
##	Execute the ssh daemon sshd domain.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed to transition.
##	</summary>
## </param>
#
interface(`ssh_domtrans',`
	gen_require(`
		type sshd_t, sshd_exec_t;
	')

	domtrans_pattern($1, sshd_exec_t, sshd_t)
')

########################################
## <summary>
##	Execute the ssh client in the caller domain.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_exec',`
	gen_require(`
		type ssh_exec_t;
	')

	corecmd_search_bin($1)
	can_exec($1, ssh_exec_t)
')

########################################
## <summary>
##	Set the attributes of sshd key files.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_setattr_key_files',`
	gen_require(`
		type sshd_key_t;
	')

	allow $1 sshd_key_t:file setattr;
	files_search_pids($1)
')

########################################
## <summary>
##	Execute the ssh agent client in the caller domain.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_agent_exec',`
	gen_require(`
		type ssh_agent_exec_t;
	')

	corecmd_search_bin($1)
	can_exec($1, ssh_agent_exec_t)
')

########################################
## <summary>
##	Read ssh home directory content
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_read_user_home_files',`
	gen_require(`
		type ssh_home_t;
	')

	allow $1 ssh_home_t:dir list_dir_perms;
	read_files_pattern($1, ssh_home_t, ssh_home_t)
	read_lnk_files_pattern($1, ssh_home_t, ssh_home_t)
	userdom_search_user_home_dirs($1)
')

########################################
## <summary>
##	Execute the ssh key generator in the ssh keygen domain.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed to transition.
##	</summary>
## </param>
#
interface(`ssh_domtrans_keygen',`
	gen_require(`
		type ssh_keygen_t, ssh_keygen_exec_t;
	')

	domtrans_pattern($1, ssh_keygen_exec_t, ssh_keygen_t)
')

########################################
## <summary>
##	Read ssh server keys
## </summary>
## <param name="domain">
##	<summary>
##	Domain to not audit.
##	</summary>
## </param>
#
interface(`ssh_dontaudit_read_server_keys',`
	gen_require(`
		type sshd_key_t;
	')

	dontaudit $1 sshd_key_t:file { getattr read };
')

######################################
## <summary>
##	Manage ssh home directory content
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_manage_home_files',`
	gen_require(`
		type ssh_home_t;
	')

	manage_files_pattern($1, ssh_home_t, ssh_home_t)
	userdom_search_user_home_dirs($1)
')

#######################################
## <summary>
##	Delete from the ssh temp files.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`ssh_delete_tmp',`
	gen_require(`
		type sshd_tmp_t;
	')

	files_search_tmp($1)
	delete_files_pattern($1, sshd_tmp_t, sshd_tmp_t)
')