2020-02-12 03:08:57

by Russell Coker

[permalink] [raw]
Subject: certbot patch

This patch against the git refpolicy adds a domain for the certbot client for
letsencrypt. This allows automatic renewal of certbot certificates.

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Attachments:
certbot.diff (5.77 kB)

2020-02-16 15:34:58

by Chris PeBenito

[permalink] [raw]
Subject: Re: certbot patch

On 2/11/20 10:08 PM, Russell Coker wrote:
> This patch against the git refpolicy adds a domain for the certbot client for
> letsencrypt. This allows automatic renewal of certbot certificates.

Please inline the patch and add signed-off-by.

> Index: refpolicy-2.20200209/policy/modules/services/certbot.fc
> ===================================================================
> --- /dev/null
> +++ refpolicy-2.20200209/policy/modules/services/certbot.fc
> @@ -0,0 +1,4 @@
> +/usr/bin/certbot --
gen_context(system_u:object_r:certbot_exec_t,s0)
> +/usr/bin/letsencrypt --
gen_context(system_u:object_r:certbot_exec_t,s0)
> +/var/log/letsencrypt(/.*)?
gen_context(system_u:object_r:certbot_log_t,s0)
> +/var/lib/letsencrypt(/.*)?
gen_context(system_u:object_r:certbot_var_lib_t,s0)
> Index: refpolicy-2.20200209/policy/modules/services/certbot.if
> ===================================================================
> --- /dev/null
> +++ refpolicy-2.20200209/policy/modules/services/certbot.if
> @@ -0,0 +1,46 @@
> +## <summary>SSL certificate requesting tool certbot AKA
letsencrypt.</summary>
> +
> +########################################
> +## <summary>
> +## Execute certbot/letsencrypt in the certbot
> +## domain.
> +## </summary>
> +## <param name="domain">
> +## <summary>
> +## Domain allowed to transition.
> +## </summary>
> +## </param>
> +#
> +interface(`certbot_domtrans',`
> + gen_require(`
> + type certbot_t, certbot_exec_t;
> + ')
> +
> + domtrans_pattern($1, certbot_exec_t, certbot_t)
> +')
> +
> +########################################
> +## <summary>
> +## Execute certbot/letsencrypt in the certbot
> +## domain, and allow the specified role
> +## the firstboot domain.
> +## </summary>
> +## <param name="role">
> +## <summary>
> +## Role allowed access.
> +## </summary>
> +## </param>
> +## <param name="domain">
> +## <summary>
> +## Domain allowed to transition.
> +## </summary>
> +## </param>
> +#
> +interface(`certbot_run',`
> + gen_require(`
> + type certbot_t;
> + ')
> +
> + certbot_domtrans($2)
> + role $1 types certbot_t;
> +')
> Index: refpolicy-2.20200209/policy/modules/services/certbot.te
> ===================================================================
> --- /dev/null
> +++ refpolicy-2.20200209/policy/modules/services/certbot.te
> @@ -0,0 +1,99 @@
> +policy_module(certbot, 1.0.0)
> +
> +########################################
> +#
> +# Declarations
> +#
> +
> +type certbot_t;
> +type certbot_exec_t;
> +init_daemon_domain(certbot_t, certbot_exec_t)
> +
> +type certbot_log_t;
> +logging_log_file(certbot_log_t)
> +
> +type certbot_var_run_t;

Please rename to certbot_runtime_t.


> +files_pid_file(certbot_var_run_t)
> +
> +type certbot_tmp_t;
> +files_tmp_file(certbot_tmp_t)
> +
> +type certbot_tmpfs_t;
> +files_tmpfs_file(certbot_tmpfs_t)
> +
> +type certbot_var_lib_t;
> +files_type(certbot_var_lib_t)

I'm trying to get away from encoding the path into the type name. Please
use certbot_lib_t or another name that makes more sense, if possible.


> +########################################
> +#
> +# Local policy
> +#
> +
> +allow certbot_t self:fifo_file { getattr ioctl read write };
> +
> +allow certbot_t self:capability { chown dac_override sys_resource };
> +
> +# this is for certbot to have write-exec memory, I know it is bad
> +allow certbot_t self:process execmem;
> +allow certbot_t certbot_tmp_t:file { map execute };
> +allow certbot_t certbot_tmpfs_t:file { map execute };
> +allow certbot_t certbot_var_run_t:file { map execute };
> +
> +kernel_search_fs_sysctls(certbot_t)
> +
> +allow certbot_t self:tcp_socket all_tcp_socket_perms;
> +allow certbot_t self:netlink_route_socket create_netlink_socket_perms;
> +corenet_tcp_bind_generic_node(certbot_t)
> +corenet_tcp_connect_http_port(certbot_t)
> +
> +# bind to http port for standalone mode
> +corenet_tcp_bind_http_port(certbot_t)
> +
> +allow certbot_t self:udp_socket all_udp_socket_perms;
> +sysnet_read_config(certbot_t)
> +files_read_etc_files(certbot_t)
> +
> +# for /usr/bin/x86_64-linux-gnu-gcc-8 why?
> +corecmd_exec_bin(certbot_t)
> +# for /usr/lib/gcc/x86_64-linux-gnu/8/collect2
> +libs_exec_lib_files(certbot_t)
> +
> +libs_exec_ldconfig(certbot_t)
> +
> +apache_search_config(certbot_t)
> +
> +# for bin_t map
> +corecmd_bin_entry_type(certbot_t)

There is a better interface that doesn't allow a bin_t entrypoint,
corecmd_mmap_bin_files().


> +miscfiles_read_localization(certbot_t)
> +
> +miscfiles_read_generic_certs(certbot_t)
> +miscfiles_manage_generic_tls_privkey_dirs(certbot_t)
> +miscfiles_manage_generic_tls_privkey_files(certbot_t)
> +miscfiles_manage_generic_tls_privkey_lnk_files(certbot_t)
> +
> +manage_files_pattern(certbot_t, certbot_var_run_t, certbot_var_run_t)
> +files_pid_filetrans(certbot_t, certbot_var_run_t, file)
> +
> +logging_search_logs(certbot_t)
> +allow certbot_t certbot_log_t:dir manage_dir_perms;
> +allow certbot_t certbot_log_t:file manage_file_perms;
> +
> +files_search_var_lib(certbot_t)
> +manage_dirs_pattern(certbot_t, certbot_var_lib_t, certbot_var_lib_t)
> +manage_files_pattern(certbot_t, certbot_var_lib_t, certbot_var_lib_t)
> +
> +manage_files_pattern(certbot_t, certbot_tmp_t, certbot_tmp_t)
> +files_tmp_filetrans(certbot_t, certbot_tmp_t, { file })
> +
> +manage_files_pattern(certbot_t, certbot_tmpfs_t, certbot_tmpfs_t)
> +fs_tmpfs_filetrans(certbot_t, certbot_tmpfs_t, { file })
> +
> +domain_use_interactive_fds(certbot_t)
> +userdom_use_user_ptys(certbot_t)
> +userdom_dontaudit_search_user_home_dirs(certbot_t)
> +
> +optional_policy(`
> + # for writing to webroot
> + apache_manage_sys_content(certbot_t)
> +')

In general the style (line ordering) needs to be revised.


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Chris PeBenito