[linux.git] / security / Kconfig

#
# Security configuration
#

menu "Security options"

config KEYS
	bool "Enable access key retention support"
	help
	  This option provides support for retaining authentication tokens and
	  access keys in the kernel.

	  It also includes provision of methods by which such keys might be
	  associated with a process so that network filesystems, encryption
	  support and the like can find them.

	  Furthermore, a special type of key is available that acts as keyring:
	  a searchable sequence of keys. Each process is equipped with access
	  to five standard keyrings: UID-specific, GID-specific, session,
	  process and thread.

	  If you are unsure as to whether this is required, answer N.

config TRUSTED_KEYS
	tristate "TRUSTED KEYS"
	depends on KEYS && TCG_TPM
	select CRYPTO
	select CRYPTO_HMAC
	select CRYPTO_SHA1
	help
	  This option provides support for creating, sealing, and unsealing
	  keys in the kernel. Trusted keys are random number symmetric keys,
	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
	  if the boot PCRs and other criteria match.  Userspace will only ever
	  see encrypted blobs.

	  If you are unsure as to whether this is required, answer N.

config ENCRYPTED_KEYS
	tristate "ENCRYPTED KEYS"
	depends on KEYS
	select CRYPTO
	select CRYPTO_HMAC
	select CRYPTO_AES
	select CRYPTO_CBC
	select CRYPTO_SHA256
	select CRYPTO_RNG
	help
	  This option provides support for create/encrypting/decrypting keys
	  in the kernel.  Encrypted keys are kernel generated random numbers,
	  which are encrypted/decrypted with a 'master' symmetric key. The
	  'master' key can be either a trusted-key or user-key type.
	  Userspace only ever sees/stores encrypted blobs.

	  If you are unsure as to whether this is required, answer N.

config KEYS_DEBUG_PROC_KEYS
	bool "Enable the /proc/keys file by which keys may be viewed"
	depends on KEYS
	help
	  This option turns on support for the /proc/keys file - through which
	  can be listed all the keys on the system that are viewable by the
	  reading process.

	  The only keys included in the list are those that grant View
	  permission to the reading process whether or not it possesses them.
	  Note that LSM security checks are still performed, and may further
	  filter out keys that the current process is not authorised to view.

	  Only key attributes are listed here; key payloads are not included in
	  the resulting table.

	  If you are unsure as to whether this is required, answer N.

config SECURITY_DMESG_RESTRICT
	bool "Restrict unprivileged access to the kernel syslog"
	default n
	help
	  This enforces restrictions on unprivileged users reading the kernel
	  syslog via dmesg(8).

	  If this option is not selected, no restrictions will be enforced
	  unless the dmesg_restrict sysctl is explicitly set to (1).

	  If you are unsure how to answer this question, answer N.

config SECURITY
	bool "Enable different security models"
	depends on SYSFS
	help
	  This allows you to choose different security modules to be
	  configured into your kernel.

	  If this option is not selected, the default Linux security
	  model will be used.

	  If you are unsure how to answer this question, answer N.

config SECURITYFS
	bool "Enable the securityfs filesystem"
	help
	  This will build the securityfs filesystem.  It is currently used by
	  the TPM bios character driver and IMA, an integrity provider.  It is
	  not used by SELinux or SMACK.

	  If you are unsure how to answer this question, answer N.

config SECURITY_NETWORK
	bool "Socket and Networking Security Hooks"
	depends on SECURITY
	help
	  This enables the socket and networking security hooks.
	  If enabled, a security module can use these hooks to
	  implement socket and networking access controls.
	  If you are unsure how to answer this question, answer N.

config SECURITY_NETWORK_XFRM
	bool "XFRM (IPSec) Networking Security Hooks"
	depends on XFRM && SECURITY_NETWORK
	help
	  This enables the XFRM (IPSec) networking security hooks.
	  If enabled, a security module can use these hooks to
	  implement per-packet access controls based on labels
	  derived from IPSec policy.  Non-IPSec communications are
	  designated as unlabelled, and only sockets authorized
	  to communicate unlabelled data can send without using
	  IPSec.
	  If you are unsure how to answer this question, answer N.

config SECURITY_PATH
	bool "Security hooks for pathname based access control"
	depends on SECURITY
	help
	  This enables the security hooks for pathname based access control.
	  If enabled, a security module can use these hooks to
	  implement pathname based access controls.
	  If you are unsure how to answer this question, answer N.

config INTEL_TXT
	bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
	depends on HAVE_INTEL_TXT
	help
	  This option enables support for booting the kernel with the
	  Trusted Boot (tboot) module. This will utilize
	  Intel(R) Trusted Execution Technology to perform a measured launch
	  of the kernel. If the system does not support Intel(R) TXT, this
	  will have no effect.

	  Intel TXT will provide higher assurance of system configuration and
	  initial state as well as data reset protection.  This is used to
	  create a robust initial kernel measurement and verification, which
	  helps to ensure that kernel security mechanisms are functioning
	  correctly. This level of protection requires a root of trust outside
	  of the kernel itself.

	  Intel TXT also helps solve real end user concerns about having
	  confidence that their hardware is running the VMM or kernel that
	  it was configured with, especially since they may be responsible for
	  providing such assurances to VMs and services running on it.

	  See <http://www.intel.com/technology/security/> for more information
	  about Intel(R) TXT.
	  See <http://tboot.sourceforge.net> for more information about tboot.
	  See Documentation/intel_txt.txt for a description of how to enable
	  Intel TXT support in a kernel boot.

	  If you are unsure as to whether this is required, answer N.

config LSM_MMAP_MIN_ADDR
	int "Low address space for LSM to protect from user allocation"
	depends on SECURITY && SECURITY_SELINUX
	default 32768 if ARM
	default 65536
	help
	  This is the portion of low virtual memory which should be protected
	  from userspace allocation.  Keeping a user from writing to low pages
	  can help reduce the impact of kernel NULL pointer bugs.

	  For most ia64, ppc64 and x86 users with lots of address space
	  a value of 65536 is reasonable and should cause no problems.
	  On arm and other archs it should not be higher than 32768.
	  Programs which use vm86 functionality or have some need to map
	  this low address space will need the permission specific to the
	  systems running LSM.

source security/selinux/Kconfig
source security/smack/Kconfig
source security/tomoyo/Kconfig
source security/apparmor/Kconfig

source security/integrity/Kconfig

choice
	prompt "Default security module"
	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
	default DEFAULT_SECURITY_DAC

	help
	  Select the security module that will be used by default if the
	  kernel parameter security= is not specified.

	config DEFAULT_SECURITY_SELINUX
		bool "SELinux" if SECURITY_SELINUX=y

	config DEFAULT_SECURITY_SMACK
		bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y

	config DEFAULT_SECURITY_TOMOYO
		bool "TOMOYO" if SECURITY_TOMOYO=y

	config DEFAULT_SECURITY_APPARMOR
		bool "AppArmor" if SECURITY_APPARMOR=y

	config DEFAULT_SECURITY_DAC
		bool "Unix Discretionary Access Controls"

endchoice

config DEFAULT_SECURITY
	string
	default "selinux" if DEFAULT_SECURITY_SELINUX
	default "smack" if DEFAULT_SECURITY_SMACK
	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
	default "apparmor" if DEFAULT_SECURITY_APPARMOR
	default "" if DEFAULT_SECURITY_DAC

endmenu
Commit	Line	Data
1da177e4 LT	1	#
	2	# Security configuration
	3	#
	4
	5	menu "Security options"
	6
	7	config KEYS
	8	bool "Enable access key retention support"
	9	help
	10	This option provides support for retaining authentication tokens and
	11	access keys in the kernel.
	12
	13	It also includes provision of methods by which such keys might be
	14	associated with a process so that network filesystems, encryption
	15	support and the like can find them.
	16
	17	Furthermore, a special type of key is available that acts as keyring:
	18	a searchable sequence of keys. Each process is equipped with access
	19	to five standard keyrings: UID-specific, GID-specific, session,
	20	process and thread.
	21
	22	If you are unsure as to whether this is required, answer N.
	23
d00a1c72 MZ	24	config TRUSTED_KEYS
	25	tristate "TRUSTED KEYS"
	26	depends on KEYS && TCG_TPM
	27	select CRYPTO
	28	select CRYPTO_HMAC
	29	select CRYPTO_SHA1
	30	help
	31	This option provides support for creating, sealing, and unsealing
	32	keys in the kernel. Trusted keys are random number symmetric keys,
	33	generated and RSA-sealed by the TPM. The TPM only unseals the keys,
	34	if the boot PCRs and other criteria match. Userspace will only ever
	35	see encrypted blobs.
	36
	37	If you are unsure as to whether this is required, answer N.
	38
7e70cb49 MZ	39	config ENCRYPTED_KEYS
7e70cb49 MZ	40	tristate "ENCRYPTED KEYS"
982e617a MZ	41	depends on KEYS
	42	select CRYPTO
	43	select CRYPTO_HMAC
7e70cb49 MZ	44	select CRYPTO_AES
	45	select CRYPTO_CBC
	46	select CRYPTO_SHA256
	47	select CRYPTO_RNG
	48	help
	49	This option provides support for create/encrypting/decrypting keys
	50	in the kernel. Encrypted keys are kernel generated random numbers,
	51	which are encrypted/decrypted with a 'master' symmetric key. The
	52	'master' key can be either a trusted-key or user-key type.
	53	Userspace only ever sees/stores encrypted blobs.
	54
	55	If you are unsure as to whether this is required, answer N.
	56
1da177e4	57	config KEYS_DEBUG_PROC_KEYS
06ec7be5	58	bool "Enable the /proc/keys file by which keys may be viewed"
1da177e4 LT	59	depends on KEYS
1da177e4 LT	60	help
06ec7be5 ML	61	This option turns on support for the /proc/keys file - through which
	62	can be listed all the keys on the system that are viewable by the
	63	reading process.
1da177e4	64
06ec7be5 ML	65	The only keys included in the list are those that grant View
	66	permission to the reading process whether or not it possesses them.
	67	Note that LSM security checks are still performed, and may further
	68	filter out keys that the current process is not authorised to view.
	69
	70	Only key attributes are listed here; key payloads are not included in
	71	the resulting table.
	72
	73	If you are unsure as to whether this is required, answer N.
1da177e4	74
eaf06b24 DR	75	config SECURITY_DMESG_RESTRICT
	76	bool "Restrict unprivileged access to the kernel syslog"
	77	default n
	78	help
	79	This enforces restrictions on unprivileged users reading the kernel
	80	syslog via dmesg(8).
	81
	82	If this option is not selected, no restrictions will be enforced
	83	unless the dmesg_restrict sysctl is explicitly set to (1).
	84
	85	If you are unsure how to answer this question, answer N.
	86
1da177e4 LT	87	config SECURITY
1da177e4 LT	88	bool "Enable different security models"
2c40579b	89	depends on SYSFS
1da177e4 LT	90	help
	91	This allows you to choose different security modules to be
	92	configured into your kernel.
	93
	94	If this option is not selected, the default Linux security
	95	model will be used.
	96
	97	If you are unsure how to answer this question, answer N.
	98
da31894e EP	99	config SECURITYFS
	100	bool "Enable the securityfs filesystem"
	101	help
	102	This will build the securityfs filesystem. It is currently used by
3323eec9 MZ	103	the TPM bios character driver and IMA, an integrity provider. It is
3323eec9 MZ	104	not used by SELinux or SMACK.
da31894e EP	105
	106	If you are unsure how to answer this question, answer N.
	107
1da177e4 LT	108	config SECURITY_NETWORK
	109	bool "Socket and Networking Security Hooks"
	110	depends on SECURITY
	111	help
	112	This enables the socket and networking security hooks.
	113	If enabled, a security module can use these hooks to
	114	implement socket and networking access controls.
	115	If you are unsure how to answer this question, answer N.
df71837d TJ	116
	117	config SECURITY_NETWORK_XFRM
	118	bool "XFRM (IPSec) Networking Security Hooks"
	119	depends on XFRM && SECURITY_NETWORK
	120	help
	121	This enables the XFRM (IPSec) networking security hooks.
	122	If enabled, a security module can use these hooks to
	123	implement per-packet access controls based on labels
	124	derived from IPSec policy. Non-IPSec communications are
	125	designated as unlabelled, and only sockets authorized
	126	to communicate unlabelled data can send without using
	127	IPSec.
	128	If you are unsure how to answer this question, answer N.
1da177e4	129
be6d3e56 KT	130	config SECURITY_PATH
	131	bool "Security hooks for pathname based access control"
	132	depends on SECURITY
	133	help
	134	This enables the security hooks for pathname based access control.
	135	If enabled, a security module can use these hooks to
	136	implement pathname based access controls.
	137	If you are unsure how to answer this question, answer N.
	138
31625340 JC	139	config INTEL_TXT
31625340 JC	140	bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
69575d38	141	depends on HAVE_INTEL_TXT
31625340 JC	142	help
	143	This option enables support for booting the kernel with the
	144	Trusted Boot (tboot) module. This will utilize
	145	Intel(R) Trusted Execution Technology to perform a measured launch
	146	of the kernel. If the system does not support Intel(R) TXT, this
	147	will have no effect.
	148
3c556e41	149	Intel TXT will provide higher assurance of system configuration and
31625340 JC	150	initial state as well as data reset protection. This is used to
	151	create a robust initial kernel measurement and verification, which
	152	helps to ensure that kernel security mechanisms are functioning
	153	correctly. This level of protection requires a root of trust outside
	154	of the kernel itself.
	155
	156	Intel TXT also helps solve real end user concerns about having
	157	confidence that their hardware is running the VMM or kernel that
3c556e41	158	it was configured with, especially since they may be responsible for
31625340 JC	159	providing such assurances to VMs and services running on it.
	160
	161	See <http://www.intel.com/technology/security/> for more information
	162	about Intel(R) TXT.
	163	See <http://tboot.sourceforge.net> for more information about tboot.
	164	See Documentation/intel_txt.txt for a description of how to enable
	165	Intel TXT support in a kernel boot.
	166
	167	If you are unsure as to whether this is required, answer N.
	168
788084ab	169	config LSM_MMAP_MIN_ADDR
024e6cb4	170	int "Low address space for LSM to protect from user allocation"
788084ab	171	depends on SECURITY && SECURITY_SELINUX
58068960	172	default 32768 if ARM
a58578e4	173	default 65536
788084ab EP	174	help
	175	This is the portion of low virtual memory which should be protected
	176	from userspace allocation. Keeping a user from writing to low pages
	177	can help reduce the impact of kernel NULL pointer bugs.
	178
	179	For most ia64, ppc64 and x86 users with lots of address space
	180	a value of 65536 is reasonable and should cause no problems.
	181	On arm and other archs it should not be higher than 32768.
	182	Programs which use vm86 functionality or have some need to map
	183	this low address space will need the permission specific to the
	184	systems running LSM.
	185
1da177e4	186	source security/selinux/Kconfig
e114e473	187	source security/smack/Kconfig
00d7d6f8	188	source security/tomoyo/Kconfig
f9ad1af5	189	source security/apparmor/Kconfig
1da177e4	190
f381c272	191	source security/integrity/Kconfig
3323eec9	192
6e65f92f JJ	193	choice
	194	prompt "Default security module"
	195	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
	196	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
	197	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
f9ad1af5	198	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
6e65f92f JJ	199	default DEFAULT_SECURITY_DAC
	200
	201	help
	202	Select the security module that will be used by default if the
	203	kernel parameter security= is not specified.
	204
	205	config DEFAULT_SECURITY_SELINUX
	206	bool "SELinux" if SECURITY_SELINUX=y
	207
	208	config DEFAULT_SECURITY_SMACK
	209	bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
	210
	211	config DEFAULT_SECURITY_TOMOYO
	212	bool "TOMOYO" if SECURITY_TOMOYO=y
	213
f9ad1af5 JJ	214	config DEFAULT_SECURITY_APPARMOR
	215	bool "AppArmor" if SECURITY_APPARMOR=y
	216
6e65f92f JJ	217	config DEFAULT_SECURITY_DAC
	218	bool "Unix Discretionary Access Controls"
	219
	220	endchoice
	221
	222	config DEFAULT_SECURITY
	223	string
	224	default "selinux" if DEFAULT_SECURITY_SELINUX
	225	default "smack" if DEFAULT_SECURITY_SMACK
	226	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
f9ad1af5	227	default "apparmor" if DEFAULT_SECURITY_APPARMOR
6e65f92f JJ	228	default "" if DEFAULT_SECURITY_DAC
6e65f92f JJ	229
1da177e4 LT	230	endmenu
1da177e4 LT	231