Integrity Service API and dummy provider
PATCH 2/7 Integrity Service API and dummy provider
This patch provides a framework and dummy provider for an integrity service. The three integrity functions provided are:
integrity_verify_metadata
integrity_verity_data
integrity_measure
(Details on the calls and their exact arguments are in linux/integrity.h, included in the patch.)
Normally these functions would be called by an LSM module during d_instantiate. The first function is used to retrieve a requested dentry's label (xattr, such as security.selinux, or security.slim.level), along with the result of integrity verification of the label.
Based on the result of this call, the LSM module may also choose to use integrity_verify_data to request a verification of the file's data, and integrity_measure, to commit the file's measurement to some form of logging/attestation service, such as a TPM.
The latter two functions are separate calls, so that the LSM module can optimize performance by using them only as needed. For example, if the integrity_verify_metadata call shows that the label is not trustworthy, it is probably not necessary to hash and measure the file, as the current LSM check will likely be denied anyway.
Updated to use more standard error returning per comments.
--- include/linux/integrity.h | 113 +++++++++++++++++++++++++++++++++++ security/Kconfig | 8 ++ security/Makefile | 1 security/integrity.c | 45 +++++++++++++ security/integrity_dummy.c | 76 +++++++++++++++++++++++ security/integrity_dummy.h | 12 +++ 6 files changed, 255 insertions(+)
security/integrity.c +45 -0
@@ -0,0 +1,45 @@ +/* +* integrity.c +* +* register integrity subsystem +* +* Copyright (C) 2005,2006 IBM Corporation +* Author: Mimi Zohar <[email protected]> +* +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation, version 2 of the License. +*/ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/integrity.h> + +#include "integrity_dummy.h" + +struct integrity_operations *integrity_ops = &dummy_integrity_ops; + +int register_integrity (struct integrity_operations *ops) +{ +if (integrity_ops != &dummy_integrity_ops) +return -EAGAIN ; + + integrity_ops = ops; +return 0 ; +} + +int unregister_integrity (struct integrity_operations *ops) +{ +if (ops != integrity_ops) +return -EINVAL ; + + integrity_ops = &dummy_integrity_ops; +return 0 ; +} + +EXPORT_SYMBOL_GPL (register_integrity); +EXPORT_SYMBOL_GPL (unregister_integrity); +EXPORT_SYMBOL_GPL (integrity_ops);
security/integrity_dummy.c +76 -0
76 lines not on this page · raw message
security/integrity_dummy.h +12 -0
@@ -0,0 +1,12 @@ +/* +* integrity_dummy.h +* +* Copyright (C) 2005,2006 IBM Corporation +* Author: Mimi Zohar <[email protected]> +* +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation, version 2 of the License. +*/ + +extern struct integrity_operations dummy_integrity_ops;
include/linux/integrity.h +113 -0
113 lines not on this page · raw message
security/Makefile +1 -0
@@ -13,6 +13,7 @@ endif # Object file lists obj-$(CONFIG_SECURITY) += security.o dummy.o inode.o +obj-$(CONFIG_INTEGRITY) += integrity.o integrity_dummy.o # Must precede capability.o in order to stack properly. obj-$(CONFIG_SECURITY_SELINUX) += selinux/built-in.o obj-$(CONFIG_SECURITY_CAPABILITIES) += commoncap.o capability.o
security/Kconfig +8 -0
@@ -39,6 +39,14 @@ config KEYS_DEBUG_PROC_KEYS If you are unsure as to whether this is required, answer N. +config INTEGRITY + bool "Enable different integrity models" + help + This allows you to choose different integrity modules to be + configured into your kernel. + + If you are unsure how to answer this question, answer N. + config SECURITY bool "Enable different security models" depends on SYSFS