# # 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 && TRUSTED_KEYS 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/ima/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