227 lines
6.8 KiB
Plaintext
227 lines
6.8 KiB
Plaintext
#DESC SSH - SSH daemon
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#
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# Authors: Anthony Colatrella (NSA) <amcolat@epoch.ncsc.mil>
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# Stephen Smalley <sds@epoch.ncsc.mil>
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# Russell Coker <russell@coker.com.au>
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# X-Debian-Packages: ssh
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#
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# Allow ssh logins as sysadm_r:sysadm_t
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bool ssh_sysadm_login false;
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ifdef(`inetd.te', `
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# Allow ssh to run from inetd instead of as a daemon.
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bool run_ssh_inetd false;
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')
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# sshd_exec_t is the type of the sshd executable.
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# sshd_key_t is the type of the ssh private key files
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type sshd_exec_t, file_type, exec_type, sysadmfile;
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type sshd_key_t, file_type, sysadmfile;
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define(`sshd_program_domain', `
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# privowner is for changing the identity on the terminal device
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# privfd is for passing the terminal file handle to the user process
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# auth_chkpwd is for running unix_chkpwd and unix_verify.
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type $1_t, domain, privuser, privrole, privlog, privowner, privfd, auth_chkpwd, nscd_client_domain, mlsfileread, mlsfilewrite, mlsfileupgrade, mlsfiledowngrade, mlsprocsetsl;
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can_exec($1_t, sshd_exec_t)
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r_dir_file($1_t, self)
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role system_r types $1_t;
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dontaudit $1_t shadow_t:file { getattr read };
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uses_shlib($1_t)
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allow $1_t self:unix_dgram_socket create_socket_perms;
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allow $1_t self:unix_stream_socket create_stream_socket_perms;
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allow $1_t self:fifo_file rw_file_perms;
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allow $1_t self:process { fork sigchld signal setsched setrlimit };
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dontaudit $1_t self:lnk_file read;
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# do not allow statfs()
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dontaudit $1_t fs_type:filesystem getattr;
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allow $1_t bin_t:dir search;
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allow $1_t bin_t:lnk_file read;
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# for sshd subsystems, such as sftp-server.
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allow $1_t bin_t:file getattr;
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# Read /var.
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allow $1_t var_t:dir { getattr search };
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# Read /var/log.
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allow $1_t var_log_t:dir search;
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# Read /etc.
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allow $1_t etc_t:dir search;
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# ioctl is for pam_console
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dontaudit $1_t etc_t:file ioctl;
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allow $1_t etc_t:file { getattr read };
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allow $1_t etc_t:lnk_file { getattr read };
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allow $1_t etc_runtime_t:file { getattr read };
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# Read and write /dev/tty and /dev/null.
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allow $1_t devtty_t:chr_file rw_file_perms;
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allow $1_t { null_device_t zero_device_t }:chr_file rw_file_perms;
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# Read /dev/urandom
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allow $1_t urandom_device_t:chr_file { getattr read };
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can_network($1_t)
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allow $1_t port_type:tcp_socket name_connect;
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can_kerberos($1_t)
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allow $1_t self:capability { kill sys_chroot sys_resource chown dac_override fowner fsetid setgid setuid sys_tty_config };
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allow $1_t { home_root_t home_dir_type }:dir { search getattr };
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if (use_nfs_home_dirs) {
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allow $1_t autofs_t:dir { search getattr };
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allow $1_t nfs_t:dir { search getattr };
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allow $1_t nfs_t:file { getattr read };
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}
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if (use_samba_home_dirs) {
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allow $1_t cifs_t:dir { search getattr };
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allow $1_t cifs_t:file { getattr read };
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}
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# Set exec context.
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can_setexec($1_t)
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# Update utmp.
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allow $1_t initrc_var_run_t:file rw_file_perms;
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# Update wtmp.
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allow $1_t wtmp_t:file rw_file_perms;
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# Get security policy decisions.
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can_getsecurity($1_t)
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# Allow read access to login context
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r_dir_file( $1_t, default_context_t)
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# Access key files
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allow $1_t sshd_key_t:file { getattr read };
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# Update /var/log/lastlog.
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allow $1_t lastlog_t:file rw_file_perms;
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read_locale($1_t)
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read_sysctl($1_t)
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# Can create ptys
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can_create_pty($1, `, server_pty')
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allow $1_t $1_devpts_t:chr_file { setattr getattr relabelfrom };
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dontaudit sshd_t userpty_type:chr_file relabelfrom;
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')dnl end sshd_program_domain
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# macro for defining which domains a sshd can spawn
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# $1_t is the domain of the sshd, $2 is the domain to be spawned, $3 is the
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# type of the pty for the child
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define(`sshd_spawn_domain', `
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login_spawn_domain($1, $2)
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ifdef(`xauth.te', `
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domain_trans($1_t, xauth_exec_t, $2)
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')
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# Relabel and access ptys created by sshd
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# ioctl is necessary for logout() processing for utmp entry and for w to
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# display the tty.
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# some versions of sshd on the new SE Linux require setattr
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allow $1_t $3:chr_file { relabelto read write getattr ioctl setattr };
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# inheriting stream sockets is needed for "ssh host command" as no pty
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# is allocated
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allow $2 $1_t:unix_stream_socket rw_stream_socket_perms;
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')dnl end sshd_spawn_domain definition
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#################################
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#
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# Rules for the sshd_t domain, et al.
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#
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# sshd_t is the domain for the sshd program.
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# sshd_extern_t is the domain for ssh from outside our network
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#
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sshd_program_domain(sshd)
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if (ssh_sysadm_login) {
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sshd_spawn_domain(sshd, userdomain, { sysadm_devpts_t userpty_type })
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} else {
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sshd_spawn_domain(sshd, unpriv_userdomain, userpty_type)
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}
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# for X forwarding
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allow sshd_t xserver_port_t:tcp_socket name_bind;
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r_dir_file(sshd_t, selinux_config_t)
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sshd_program_domain(sshd_extern)
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sshd_spawn_domain(sshd_extern, user_mini_domain, mini_pty_type)
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# for when the network connection breaks after running newrole -r sysadm_r
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dontaudit sshd_t sysadm_devpts_t:chr_file setattr;
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# Allow checking users mail at login
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allow sshd_t { var_spool_t mail_spool_t }:dir search;
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allow sshd_t mail_spool_t:lnk_file read;
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allow sshd_t mail_spool_t:file getattr;
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ifdef(`inetd.te', `
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if (run_ssh_inetd) {
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allow inetd_t ssh_port_t:tcp_socket name_bind;
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domain_auto_trans(inetd_t, sshd_exec_t, sshd_t)
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domain_trans(inetd_t, sshd_exec_t, sshd_extern_t)
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allow { sshd_t sshd_extern_t } inetd_t:tcp_socket rw_socket_perms;
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allow { sshd_t sshd_extern_t } var_run_t:dir { getattr search };
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allow { sshd_t sshd_extern_t } self:process signal;
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} else {
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')
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allow { sshd_t sshd_extern_t } initrc_devpts_t:chr_file rw_file_perms;
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allow { sshd_t sshd_extern_t } self:capability net_bind_service;
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allow { sshd_t sshd_extern_t } ssh_port_t:tcp_socket name_bind;
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# for port forwarding
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can_tcp_connect(userdomain, sshd_t)
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domain_auto_trans(initrc_t, sshd_exec_t, sshd_t)
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domain_trans(initrc_t, sshd_exec_t, sshd_extern_t)
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dontaudit initrc_t sshd_key_t:file { getattr read };
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# Inherit and use descriptors from init.
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allow { sshd_t sshd_extern_t } init_t:fd use;
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ifdef(`inetd.te', `
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}
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')
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# Create /var/run/sshd.pid
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var_run_domain(sshd)
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var_run_domain(sshd_extern)
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ifdef(`direct_sysadm_daemon', `
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# Direct execution by sysadm_r.
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domain_auto_trans(sysadm_t, sshd_exec_t, sshd_t)
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role_transition sysadm_r sshd_exec_t system_r;
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')
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undefine(`sshd_program_domain')
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# so a tunnel can point to another ssh tunnel...
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can_tcp_connect(sshd_t, sshd_t)
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tmp_domain(sshd, `', { dir file sock_file })
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ifdef(`pam.te', `
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can_exec(sshd_t, pam_exec_t)
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')
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# ssh_keygen_t is the type of the ssh-keygen program when run at install time
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# and by sysadm_t
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daemon_base_domain(ssh_keygen)
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allow ssh_keygen_t etc_t:file { getattr read };
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file_type_auto_trans(ssh_keygen_t, etc_t, sshd_key_t, file)
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# Type for the ssh executable.
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type ssh_exec_t, file_type, exec_type, sysadmfile;
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# Everything else is in the ssh_domain macro in
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# macros/program/ssh_macros.te.
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allow ssh_keygen_t self:unix_stream_socket create_stream_socket_perms;
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allow ssh_keygen_t sysadm_tty_device_t:chr_file { read write };
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allow ssh_keygen_t urandom_device_t:chr_file { getattr read };
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