# IBM Integrity Measurement Architecture
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#
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config IMA
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bool "Integrity Measurement Architecture(IMA)"
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select SECURITYFS
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select CRYPTO
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select CRYPTO_HMAC
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select CRYPTO_SHA1
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select CRYPTO_HASH_INFO
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select TCG_TPM if HAS_IOMEM && !UML
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select TCG_TIS if TCG_TPM && X86
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select TCG_CRB if TCG_TPM && ACPI
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select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES
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select INTEGRITY_AUDIT if AUDIT
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help
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The Trusted Computing Group(TCG) runtime Integrity
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Measurement Architecture(IMA) maintains a list of hash
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values of executables and other sensitive system files,
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as they are read or executed. If an attacker manages
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to change the contents of an important system file
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being measured, we can tell.
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If your system has a TPM chip, then IMA also maintains
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an aggregate integrity value over this list inside the
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TPM hardware, so that the TPM can prove to a third party
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whether or not critical system files have been modified.
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Read <http://www.usenix.org/events/sec04/tech/sailer.html>
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to learn more about IMA.
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If unsure, say N.
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config IMA_KEXEC
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bool "Enable carrying the IMA measurement list across a soft boot"
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depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
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default n
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help
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TPM PCRs are only reset on a hard reboot. In order to validate
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a TPM's quote after a soft boot, the IMA measurement list of the
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running kernel must be saved and restored on boot.
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Depending on the IMA policy, the measurement list can grow to
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be very large.
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config IMA_MEASURE_PCR_IDX
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int
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depends on IMA
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range 8 14
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default 10
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help
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IMA_MEASURE_PCR_IDX determines the TPM PCR register index
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that IMA uses to maintain the integrity aggregate of the
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measurement list. If unsure, use the default 10.
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config IMA_LSM_RULES
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bool
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depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
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default y
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help
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Disabling this option will disregard LSM based policy rules.
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choice
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prompt "Default template"
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default IMA_NG_TEMPLATE
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depends on IMA
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help
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Select the default IMA measurement template.
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The original 'ima' measurement list template contains a
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hash, defined as 20 bytes, and a null terminated pathname,
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limited to 255 characters. The 'ima-ng' measurement list
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template permits both larger hash digests and longer
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pathnames.
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config IMA_TEMPLATE
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bool "ima"
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config IMA_NG_TEMPLATE
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bool "ima-ng (default)"
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config IMA_SIG_TEMPLATE
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bool "ima-sig"
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endchoice
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config IMA_DEFAULT_TEMPLATE
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string
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depends on IMA
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default "ima" if IMA_TEMPLATE
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default "ima-ng" if IMA_NG_TEMPLATE
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default "ima-sig" if IMA_SIG_TEMPLATE
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choice
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prompt "Default integrity hash algorithm"
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default IMA_DEFAULT_HASH_SHA1
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depends on IMA
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help
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Select the default hash algorithm used for the measurement
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list, integrity appraisal and audit log. The compiled default
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hash algorithm can be overwritten using the kernel command
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line 'ima_hash=' option.
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config IMA_DEFAULT_HASH_SHA1
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bool "SHA1 (default)"
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depends on CRYPTO_SHA1=y
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config IMA_DEFAULT_HASH_SHA256
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bool "SHA256"
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depends on CRYPTO_SHA256=y && !IMA_TEMPLATE
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config IMA_DEFAULT_HASH_SHA512
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bool "SHA512"
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depends on CRYPTO_SHA512=y && !IMA_TEMPLATE
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config IMA_DEFAULT_HASH_WP512
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bool "WP512"
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depends on CRYPTO_WP512=y && !IMA_TEMPLATE
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endchoice
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config IMA_DEFAULT_HASH
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string
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depends on IMA
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default "sha1" if IMA_DEFAULT_HASH_SHA1
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default "sha256" if IMA_DEFAULT_HASH_SHA256
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default "sha512" if IMA_DEFAULT_HASH_SHA512
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default "wp512" if IMA_DEFAULT_HASH_WP512
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config IMA_WRITE_POLICY
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bool "Enable multiple writes to the IMA policy"
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depends on IMA
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default n
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help
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IMA policy can now be updated multiple times. The new rules get
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appended to the original policy. Have in mind that the rules are
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scanned in FIFO order so be careful when you design and add new ones.
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If unsure, say N.
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config IMA_READ_POLICY
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bool "Enable reading back the current IMA policy"
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depends on IMA
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default y if IMA_WRITE_POLICY
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default n if !IMA_WRITE_POLICY
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help
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It is often useful to be able to read back the IMA policy. It is
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even more important after introducing CONFIG_IMA_WRITE_POLICY.
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This option allows the root user to see the current policy rules.
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config IMA_APPRAISE
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bool "Appraise integrity measurements"
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depends on IMA
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default n
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help
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This option enables local measurement integrity appraisal.
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It requires the system to be labeled with a security extended
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attribute containing the file hash measurement. To protect
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the security extended attributes from offline attack, enable
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and configure EVM.
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For more information on integrity appraisal refer to:
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<http://linux-ima.sourceforge.net>
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If unsure, say N.
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config IMA_APPRAISE_BUILD_POLICY
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bool "IMA build time configured policy rules"
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depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
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default n
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help
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This option defines an IMA appraisal policy at build time, which
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is enforced at run time without having to specify a builtin
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policy name on the boot command line. The build time appraisal
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policy rules persist after loading a custom policy.
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Depending on the rules configured, this policy may require kernel
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modules, firmware, the kexec kernel image, and/or the IMA policy
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to be signed. Unsigned files might prevent the system from
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booting or applications from working properly.
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config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
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bool "Appraise firmware signatures"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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This option defines a policy requiring all firmware to be signed,
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including the regulatory.db. If both this option and
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CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature
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verification methods are necessary.
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config IMA_APPRAISE_REQUIRE_KEXEC_SIGS
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bool "Appraise kexec kernel image signatures"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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Enabling this rule will require all kexec'ed kernel images to
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be signed and verified by a public key on the trusted IMA
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keyring.
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Kernel image signatures can not be verified by the original
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kexec_load syscall. Enabling this rule will prevent its
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usage.
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config IMA_APPRAISE_REQUIRE_MODULE_SIGS
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bool "Appraise kernel modules signatures"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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Enabling this rule will require all kernel modules to be signed
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and verified by a public key on the trusted IMA keyring.
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Kernel module signatures can only be verified by IMA-appraisal,
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via the finit_module syscall. Enabling this rule will prevent
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the usage of the init_module syscall.
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config IMA_APPRAISE_REQUIRE_POLICY_SIGS
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bool "Appraise IMA policy signature"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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Enabling this rule will require the IMA policy to be signed and
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and verified by a key on the trusted IMA keyring.
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config IMA_APPRAISE_BOOTPARAM
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bool "ima_appraise boot parameter"
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depends on IMA_APPRAISE
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default y
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help
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This option enables the different "ima_appraise=" modes
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(eg. fix, log) from the boot command line.
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config IMA_TRUSTED_KEYRING
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bool "Require all keys on the .ima keyring be signed (deprecated)"
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depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
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depends on INTEGRITY_ASYMMETRIC_KEYS
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select INTEGRITY_TRUSTED_KEYRING
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default y
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help
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This option requires that all keys added to the .ima
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keyring be signed by a key on the system trusted keyring.
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This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
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config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
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bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
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depends on SYSTEM_TRUSTED_KEYRING
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depends on SECONDARY_TRUSTED_KEYRING
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depends on INTEGRITY_ASYMMETRIC_KEYS
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select INTEGRITY_TRUSTED_KEYRING
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default n
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help
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Keys may be added to the IMA or IMA blacklist keyrings, if the
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key is validly signed by a CA cert in the system built-in or
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secondary trusted keyrings.
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Intermediate keys between those the kernel has compiled in and the
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IMA keys to be added may be added to the system secondary keyring,
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provided they are validly signed by a key already resident in the
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built-in or secondary trusted keyrings.
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config IMA_BLACKLIST_KEYRING
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bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
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depends on SYSTEM_TRUSTED_KEYRING
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depends on IMA_TRUSTED_KEYRING
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default n
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help
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This option creates an IMA blacklist keyring, which contains all
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revoked IMA keys. It is consulted before any other keyring. If
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the search is successful the requested operation is rejected and
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an error is returned to the caller.
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config IMA_LOAD_X509
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bool "Load X509 certificate onto the '.ima' trusted keyring"
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depends on IMA_TRUSTED_KEYRING
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default n
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help
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File signature verification is based on the public keys
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loaded on the .ima trusted keyring. These public keys are
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X509 certificates signed by a trusted key on the
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.system keyring. This option enables X509 certificate
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loading from the kernel onto the '.ima' trusted keyring.
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config IMA_X509_PATH
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string "IMA X509 certificate path"
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depends on IMA_LOAD_X509
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default "/etc/keys/x509_ima.der"
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help
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This option defines IMA X509 certificate path.
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config IMA_APPRAISE_SIGNED_INIT
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bool "Require signed user-space initialization"
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depends on IMA_LOAD_X509
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default n
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help
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This option requires user-space init to be signed.
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