d00a1c72f7
Define a new kernel key-type called 'trusted'. 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 can only ever see encrypted blobs.
Based on suggestions by Jason Gunthorpe, several new options have been
added to support additional usages.
The new options are:
migratable= designates that the key may/may not ever be updated
(resealed under a new key, new pcrinfo or new auth.)
pcrlock=n extends the designated PCR 'n' with a random value,
so that a key sealed to that PCR may not be unsealed
again until after a reboot.
keyhandle= specifies the sealing/unsealing key handle.
keyauth= specifies the sealing/unsealing key auth.
blobauth= specifies the sealed data auth.
Implementation of a kernel reserved locality for trusted keys will be
investigated for a possible future extension.
Changelog:
- Updated and added examples to Documentation/keys-trusted-encrypted.txt
- Moved generic TPM constants to include/linux/tpm_command.h
(David Howell's suggestion.)
- trusted_defined.c: replaced kzalloc with kmalloc, added pcrlock failure
error handling, added const qualifiers where appropriate.
- moved to late_initcall
- updated from hash to shash (suggestion by David Howells)
- reduced worst stack usage (tpm_seal) from 530 to 312 bytes
- moved documentation to Documentation directory (suggestion by David Howells)
- all the other code cleanups suggested by David Howells
- Add pcrlock CAP_SYS_ADMIN dependency (based on comment by Jason Gunthorpe)
- New options: migratable, pcrlock, keyhandle, keyauth, blobauth (based on
discussions with Jason Gunthorpe)
- Free payload on failure to create key(reported/fixed by Roberto Sassu)
- Updated Kconfig and other descriptions (based on Serge Hallyn's suggestion)
- Replaced kzalloc() with kmalloc() (reported by Serge Hallyn)
Signed-off-by: David Safford <safford@watson.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
212 lines
7.3 KiB
Text
212 lines
7.3 KiB
Text
#
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# Security configuration
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#
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menu "Security options"
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config KEYS
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bool "Enable access key retention support"
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help
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This option provides support for retaining authentication tokens and
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access keys in the kernel.
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It also includes provision of methods by which such keys might be
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associated with a process so that network filesystems, encryption
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support and the like can find them.
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Furthermore, a special type of key is available that acts as keyring:
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a searchable sequence of keys. Each process is equipped with access
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to five standard keyrings: UID-specific, GID-specific, session,
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process and thread.
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If you are unsure as to whether this is required, answer N.
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config TRUSTED_KEYS
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tristate "TRUSTED KEYS"
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depends on KEYS && TCG_TPM
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select CRYPTO
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select CRYPTO_HMAC
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select CRYPTO_SHA1
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help
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This option provides support for creating, sealing, and unsealing
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keys in the kernel. Trusted keys are random number symmetric keys,
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generated and RSA-sealed by the TPM. The TPM only unseals the keys,
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if the boot PCRs and other criteria match. Userspace will only ever
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see encrypted blobs.
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If you are unsure as to whether this is required, answer N.
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config KEYS_DEBUG_PROC_KEYS
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bool "Enable the /proc/keys file by which keys may be viewed"
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depends on KEYS
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help
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This option turns on support for the /proc/keys file - through which
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can be listed all the keys on the system that are viewable by the
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reading process.
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The only keys included in the list are those that grant View
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permission to the reading process whether or not it possesses them.
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Note that LSM security checks are still performed, and may further
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filter out keys that the current process is not authorised to view.
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Only key attributes are listed here; key payloads are not included in
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the resulting table.
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If you are unsure as to whether this is required, answer N.
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config SECURITY_DMESG_RESTRICT
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bool "Restrict unprivileged access to the kernel syslog"
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default n
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help
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This enforces restrictions on unprivileged users reading the kernel
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syslog via dmesg(8).
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If this option is not selected, no restrictions will be enforced
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unless the dmesg_restrict sysctl is explicitly set to (1).
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If you are unsure how to answer this question, answer N.
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config SECURITY
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bool "Enable different security models"
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depends on SYSFS
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help
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This allows you to choose different security modules to be
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configured into your kernel.
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If this option is not selected, the default Linux security
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model will be used.
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If you are unsure how to answer this question, answer N.
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config SECURITYFS
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bool "Enable the securityfs filesystem"
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help
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This will build the securityfs filesystem. It is currently used by
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the TPM bios character driver and IMA, an integrity provider. It is
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not used by SELinux or SMACK.
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If you are unsure how to answer this question, answer N.
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config SECURITY_NETWORK
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bool "Socket and Networking Security Hooks"
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depends on SECURITY
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help
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This enables the socket and networking security hooks.
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If enabled, a security module can use these hooks to
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implement socket and networking access controls.
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If you are unsure how to answer this question, answer N.
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config SECURITY_NETWORK_XFRM
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bool "XFRM (IPSec) Networking Security Hooks"
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depends on XFRM && SECURITY_NETWORK
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help
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This enables the XFRM (IPSec) networking security hooks.
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If enabled, a security module can use these hooks to
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implement per-packet access controls based on labels
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derived from IPSec policy. Non-IPSec communications are
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designated as unlabelled, and only sockets authorized
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to communicate unlabelled data can send without using
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IPSec.
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If you are unsure how to answer this question, answer N.
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config SECURITY_PATH
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bool "Security hooks for pathname based access control"
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depends on SECURITY
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help
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This enables the security hooks for pathname based access control.
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If enabled, a security module can use these hooks to
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implement pathname based access controls.
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If you are unsure how to answer this question, answer N.
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config INTEL_TXT
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bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
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depends on HAVE_INTEL_TXT
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help
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This option enables support for booting the kernel with the
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Trusted Boot (tboot) module. This will utilize
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Intel(R) Trusted Execution Technology to perform a measured launch
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of the kernel. If the system does not support Intel(R) TXT, this
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will have no effect.
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Intel TXT will provide higher assurance of system configuration and
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initial state as well as data reset protection. This is used to
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create a robust initial kernel measurement and verification, which
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helps to ensure that kernel security mechanisms are functioning
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correctly. This level of protection requires a root of trust outside
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of the kernel itself.
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Intel TXT also helps solve real end user concerns about having
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confidence that their hardware is running the VMM or kernel that
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it was configured with, especially since they may be responsible for
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providing such assurances to VMs and services running on it.
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See <http://www.intel.com/technology/security/> for more information
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about Intel(R) TXT.
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See <http://tboot.sourceforge.net> for more information about tboot.
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See Documentation/intel_txt.txt for a description of how to enable
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Intel TXT support in a kernel boot.
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If you are unsure as to whether this is required, answer N.
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config LSM_MMAP_MIN_ADDR
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int "Low address space for LSM to protect from user allocation"
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depends on SECURITY && SECURITY_SELINUX
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default 65536
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help
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This is the portion of low virtual memory which should be protected
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from userspace allocation. Keeping a user from writing to low pages
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can help reduce the impact of kernel NULL pointer bugs.
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For most ia64, ppc64 and x86 users with lots of address space
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a value of 65536 is reasonable and should cause no problems.
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On arm and other archs it should not be higher than 32768.
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Programs which use vm86 functionality or have some need to map
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this low address space will need the permission specific to the
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systems running LSM.
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source security/selinux/Kconfig
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source security/smack/Kconfig
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source security/tomoyo/Kconfig
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source security/apparmor/Kconfig
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source security/integrity/ima/Kconfig
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choice
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prompt "Default security module"
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default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
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default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
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default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
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default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
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default DEFAULT_SECURITY_DAC
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help
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Select the security module that will be used by default if the
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kernel parameter security= is not specified.
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config DEFAULT_SECURITY_SELINUX
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bool "SELinux" if SECURITY_SELINUX=y
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config DEFAULT_SECURITY_SMACK
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bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
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config DEFAULT_SECURITY_TOMOYO
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bool "TOMOYO" if SECURITY_TOMOYO=y
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config DEFAULT_SECURITY_APPARMOR
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bool "AppArmor" if SECURITY_APPARMOR=y
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config DEFAULT_SECURITY_DAC
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bool "Unix Discretionary Access Controls"
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endchoice
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config DEFAULT_SECURITY
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string
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default "selinux" if DEFAULT_SECURITY_SELINUX
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default "smack" if DEFAULT_SECURITY_SMACK
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default "tomoyo" if DEFAULT_SECURITY_TOMOYO
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default "apparmor" if DEFAULT_SECURITY_APPARMOR
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default "" if DEFAULT_SECURITY_DAC
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endmenu
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