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Haveged support in (audio)entropyd

PATCH Superseded Sven Vermeulen 1 participant 4 messages Jul 20, 2011

v2 of 4 Superseded Latest is v4 →

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#0 lore raw

PATCH v2 1/1 Haveged support in (audio)entropyd

This patch set segregates the obvious audio-related privileges within entropyd_t (in the audioentropyd module) through the use of a SELinux boolean "entropyd_use_audio", enhances the entropyd_t with the privileges needed by haveged, and adds the proper file contexts for haveged support.

Comments always appreciated. This obsoletes the previous patch set titled "Haveged definition".

Wkr,
Sven Vermeulen

#1 lore raw

PATCH 1/3 Separate sound-specific items from general entropyd_t definitions

Introduce a tunable called "entropyd_use_audio". This boolean triggers the privileges that are specific for audio support (both device access as well as the alsa-specific ones).

The idea to use a boolean is to support other entropy management applications/daemons which use different sources (like haveged using the HAVEGE algorithm).

---
 policy/modules/services/audioentropy.te |   26 ++++++++++++++++++--------
 1 files changed, 18 insertions(+), 8 deletions(-)
policy/modules/services/audioentropy.te +18 -8
index 2b348c7..08c1d8c 100644
@@ -5,6 +5,13 @@ policy_module(audioentropy, 1.6.0)
 # Declarations
 #
 
+## <desc>
+## <p>
+##   Allow the use of the audio devices as the source for the entropy feeds
+## </p>
+## </desc>
+gen_tunable(entropyd_use_audio, false)
+
 type entropyd_t;
 type entropyd_exec_t;
 init_daemon_domain(entropyd_t, entropyd_exec_t)
@@ -33,11 +40,6 @@ dev_read_urand(entropyd_t)
 dev_write_urand(entropyd_t)
 dev_read_rand(entropyd_t)
 dev_write_rand(entropyd_t)
-dev_read_sound(entropyd_t)
-# set sound card parameters such as
-# sample format, number of channels
-# and sample rate.
-dev_write_sound(entropyd_t)
 
 files_read_etc_files(entropyd_t)
 files_read_usr_files(entropyd_t)
@@ -54,9 +56,17 @@ miscfiles_read_localization(entropyd_t)
 userdom_dontaudit_use_unpriv_user_fds(entropyd_t)
 userdom_dontaudit_search_user_home_dirs(entropyd_t)
 
-optional_policy(`
-	alsa_read_lib(entropyd_t)
-	alsa_read_rw_config(entropyd_t)
+tunable_policy(`entropyd_use_audio',`
+
+	dev_read_sound(entropyd_t)
+	# set sound card parameters such as sample format, number of channels
+	# and sample rate.
+	dev_write_sound(entropyd_t)
+
+	optional_policy(`
+		alsa_read_lib(entropyd_t)
+		alsa_read_rw_config(entropyd_t)
+	')
 ')
 
 optional_policy(`
Signature · 1 line
1.7.3.4
#2 lore raw

PATCH 2/3 Update entropyd_t with privileges needed for haveged support

In reply to Sven Vermeulen

Haveged by itself requires a few additional privileges (create a unix socket and write access to some proc/sys/kernel files (like /proc/sys/kernel/random/write_wakeup_threshold).

---
 policy/modules/services/audioentropy.te |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
policy/modules/services/audioentropy.te +2 -1
index 08c1d8c..b224ebf 100644
@@ -27,11 +27,12 @@ files_pid_file(entropyd_var_run_t)
 allow entropyd_t self:capability { dac_override ipc_lock sys_admin };
 dontaudit entropyd_t self:capability sys_tty_config;
 allow entropyd_t self:process signal_perms;
+allow entropyd_t self:unix_dgram_socket create_socket_perms;
 
 manage_files_pattern(entropyd_t, entropyd_var_run_t, entropyd_var_run_t)
 files_pid_filetrans(entropyd_t, entropyd_var_run_t, file)
 
-kernel_read_kernel_sysctls(entropyd_t)
+kernel_rw_kernel_sysctl(entropyd_t)
 kernel_list_proc(entropyd_t)
 kernel_read_proc_symlinks(entropyd_t)
 
Signature · 1 line
1.7.3.4
#3 lore raw

PATCH 3/3 Add file context rules for haveged

In reply to Sven Vermeulen

Add file context rules for haveged within the audioentropyd module.

---
 policy/modules/services/audioentropy.fc |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
policy/modules/services/audioentropy.fc +2 -0
index 001235e..d2d8ce3 100644
@@ -2,5 +2,7 @@
 # /usr
 #
 /usr/sbin/audio-entropyd	--	gen_context(system_u:object_r:entropyd_exec_t,s0)
+/usr/sbin/haveged		--	gen_context(system_u:object_r:entropyd_exec_t,s0)
 
 /var/run/audio-entropyd\.pid	--	gen_context(system_u:object_r:entropyd_var_run_t,s0)
+/var/run/haveged\.pid		--	gen_context(system_u:object_r:entropyd_var_run_t,s0)
Signature · 1 line
1.7.3.4