forked from luck/tmp_suning_uos_patched
9dc92c4517
On secure boot enabled systems, a verified kernel may need to kexec additional kernels. For example, it may be used as a bootloader needing to kexec a target kernel or it may need to kexec a crashdump kernel. In such cases, it may want to verify the signature of the next kernel image. It is further possible that the kernel image is signed with third party keys which are stored as platform or firmware keys in the 'db' variable. The kernel, however, can not directly verify these platform keys, and an administrator may therefore not want to trust them for arbitrary usage. In order to differentiate platform keys from other keys and provide the necessary separation of trust, the kernel needs an additional keyring to store platform keys. This patch creates the new keyring called ".platform" to isolate keys provided by platform from keys by kernel. These keys are used to facilitate signature verification during kexec. Since the scope of this keyring is only the platform/firmware keys, it cannot be updated from userspace. This keyring can be enabled by setting CONFIG_INTEGRITY_PLATFORM_KEYRING. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: James Morris <james.morris@microsoft.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
84 lines
2.8 KiB
Plaintext
84 lines
2.8 KiB
Plaintext
#
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config INTEGRITY
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bool "Integrity subsystem"
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depends on SECURITY
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default y
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help
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This option enables the integrity subsystem, which is comprised
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of a number of different components including the Integrity
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Measurement Architecture (IMA), Extended Verification Module
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(EVM), IMA-appraisal extension, digital signature verification
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extension and audit measurement log support.
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Each of these components can be enabled/disabled separately.
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Refer to the individual components for additional details.
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if INTEGRITY
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config INTEGRITY_SIGNATURE
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bool "Digital signature verification using multiple keyrings"
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depends on KEYS
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default n
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select SIGNATURE
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help
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This option enables digital signature verification support
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using multiple keyrings. It defines separate keyrings for each
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of the different use cases - evm, ima, and modules.
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Different keyrings improves search performance, but also allow
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to "lock" certain keyring to prevent adding new keys.
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This is useful for evm and module keyrings, when keys are
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usually only added from initramfs.
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config INTEGRITY_ASYMMETRIC_KEYS
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bool "Enable asymmetric keys support"
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depends on INTEGRITY_SIGNATURE
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default n
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select ASYMMETRIC_KEY_TYPE
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select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
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select CRYPTO_RSA
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select X509_CERTIFICATE_PARSER
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help
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This option enables digital signature verification using
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asymmetric keys.
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config INTEGRITY_TRUSTED_KEYRING
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bool "Require all keys on the integrity keyrings be signed"
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depends on SYSTEM_TRUSTED_KEYRING
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depends on INTEGRITY_ASYMMETRIC_KEYS
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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 and
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.evm keyrings be signed by a key on the system trusted
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keyring.
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config INTEGRITY_PLATFORM_KEYRING
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bool "Provide keyring for platform/firmware trusted keys"
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depends on INTEGRITY_ASYMMETRIC_KEYS
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depends on SYSTEM_BLACKLIST_KEYRING
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depends on EFI
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help
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Provide a separate, distinct keyring for platform trusted keys, which
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the kernel automatically populates during initialization from values
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provided by the platform for verifying the kexec'ed kerned image
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and, possibly, the initramfs signature.
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config INTEGRITY_AUDIT
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bool "Enables integrity auditing support "
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depends on AUDIT
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default y
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help
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In addition to enabling integrity auditing support, this
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option adds a kernel parameter 'integrity_audit', which
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controls the level of integrity auditing messages.
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0 - basic integrity auditing messages (default)
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1 - additional integrity auditing messages
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Additional informational integrity auditing messages would
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be enabled by specifying 'integrity_audit=1' on the kernel
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command line.
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source security/integrity/ima/Kconfig
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source security/integrity/evm/Kconfig
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endif # if INTEGRITY
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