security/Kconfig

   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
  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
  39 config ENCRYPTED_KEYS
  40         tristate "ENCRYPTED KEYS"
  41         depends on KEYS
  42         select CRYPTO
  43         select CRYPTO_HMAC
  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
  57 config KEYS_DEBUG_PROC_KEYS
  58         bool "Enable the /proc/keys file by which keys may be viewed"
  59         depends on KEYS
  60         help
  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.
  64
  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.
  74
  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
  87 config SECURITY
  88         bool "Enable different security models"
  89         depends on SYSFS
  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
  99 config SECURITYFS
 100         bool "Enable the securityfs filesystem"
 101         help
 102           This will build the securityfs filesystem.  It is currently used by
 103           the TPM bios character driver and IMA, an integrity provider.  It is
 104           not used by SELinux or SMACK.
 105
 106           If you are unsure how to answer this question, answer N.
 107
 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.
 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.
 129
 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
 139 config INTEL_TXT
 140         bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
 141         depends on HAVE_INTEL_TXT
 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
 149           Intel TXT will provide higher assurance of system configuration and
 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
 158           it was configured with, especially since they may be responsible for
 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
 169 config LSM_MMAP_MIN_ADDR
 170         int "Low address space for LSM to protect from user allocation"
 171         depends on SECURITY && SECURITY_SELINUX
 172         default 32768 if ARM
 173         default 65536
 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
 186 source security/selinux/Kconfig
 187 source security/smack/Kconfig
 188 source security/tomoyo/Kconfig
 189 source security/apparmor/Kconfig
 190 source security/yama/Kconfig
 191
 192 source security/integrity/Kconfig
 193
 194 choice
 195         prompt "Default security module"
 196         default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
 197         default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
 198         default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
 199         default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
 200         default DEFAULT_SECURITY_YAMA if SECURITY_YAMA
 201         default DEFAULT_SECURITY_DAC
 202
 203         help
 204           Select the security module that will be used by default if the
 205           kernel parameter security= is not specified.
 206
 207         config DEFAULT_SECURITY_SELINUX
 208                 bool "SELinux" if SECURITY_SELINUX=y
 209
 210         config DEFAULT_SECURITY_SMACK
 211                 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
 212
 213         config DEFAULT_SECURITY_TOMOYO
 214                 bool "TOMOYO" if SECURITY_TOMOYO=y
 215
 216         config DEFAULT_SECURITY_APPARMOR
 217                 bool "AppArmor" if SECURITY_APPARMOR=y
 218
 219         config DEFAULT_SECURITY_YAMA
 220                 bool "Yama" if SECURITY_YAMA=y
 221
 222         config DEFAULT_SECURITY_DAC
 223                 bool "Unix Discretionary Access Controls"
 224
 225 endchoice
 226
 227 config DEFAULT_SECURITY
 228         string
 229         default "selinux" if DEFAULT_SECURITY_SELINUX
 230         default "smack" if DEFAULT_SECURITY_SMACK
 231         default "tomoyo" if DEFAULT_SECURITY_TOMOYO
 232         default "apparmor" if DEFAULT_SECURITY_APPARMOR
 233         default "yama" if DEFAULT_SECURITY_YAMA
 234         default "" if DEFAULT_SECURITY_DAC
 235
 236 endmenu
 237