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linux/security/ipe/policy.h
Fan Wu 31f8c8682f ipe: enable support for fs-verity as a trust provider
Enable IPE policy authors to indicate trust for a singular fsverity
file, identified by the digest information, through "fsverity_digest"
and all files using valid fsverity builtin signatures via
"fsverity_signature".

This enables file-level integrity claims to be expressed in IPE,
allowing individual files to be authorized, giving some flexibility
for policy authors. Such file-level claims are important to be expressed
for enforcing the integrity of packages, as well as address some of the
scalability issues in a sole dm-verity based solution (# of loop back
devices, etc).

This solution cannot be done in userspace as the minimum threat that
IPE should mitigate is an attacker downloads malicious payload with
all required dependencies. These dependencies can lack the userspace
check, bypassing the protection entirely. A similar attack succeeds if
the userspace component is replaced with a version that does not
perform the check. As a result, this can only be done in the common
entry point - the kernel.

Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-08-20 14:03:35 -04:00

99 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
*/
#ifndef _IPE_POLICY_H
#define _IPE_POLICY_H
#include <linux/list.h>
#include <linux/types.h>
#include <linux/fs.h>
enum ipe_op_type {
IPE_OP_EXEC = 0,
IPE_OP_FIRMWARE,
IPE_OP_KERNEL_MODULE,
IPE_OP_KEXEC_IMAGE,
IPE_OP_KEXEC_INITRAMFS,
IPE_OP_POLICY,
IPE_OP_X509,
__IPE_OP_MAX,
};
#define IPE_OP_INVALID __IPE_OP_MAX
enum ipe_action_type {
IPE_ACTION_ALLOW = 0,
IPE_ACTION_DENY,
__IPE_ACTION_MAX
};
#define IPE_ACTION_INVALID __IPE_ACTION_MAX
enum ipe_prop_type {
IPE_PROP_BOOT_VERIFIED_FALSE,
IPE_PROP_BOOT_VERIFIED_TRUE,
IPE_PROP_DMV_ROOTHASH,
IPE_PROP_DMV_SIG_FALSE,
IPE_PROP_DMV_SIG_TRUE,
IPE_PROP_FSV_DIGEST,
IPE_PROP_FSV_SIG_FALSE,
IPE_PROP_FSV_SIG_TRUE,
__IPE_PROP_MAX
};
#define IPE_PROP_INVALID __IPE_PROP_MAX
struct ipe_prop {
struct list_head next;
enum ipe_prop_type type;
void *value;
};
struct ipe_rule {
enum ipe_op_type op;
enum ipe_action_type action;
struct list_head props;
struct list_head next;
};
struct ipe_op_table {
struct list_head rules;
enum ipe_action_type default_action;
};
struct ipe_parsed_policy {
const char *name;
struct {
u16 major;
u16 minor;
u16 rev;
} version;
enum ipe_action_type global_default_action;
struct ipe_op_table rules[__IPE_OP_MAX];
};
struct ipe_policy {
const char *pkcs7;
size_t pkcs7len;
const char *text;
size_t textlen;
struct ipe_parsed_policy *parsed;
struct dentry *policyfs;
};
struct ipe_policy *ipe_new_policy(const char *text, size_t textlen,
const char *pkcs7, size_t pkcs7len);
void ipe_free_policy(struct ipe_policy *pol);
int ipe_update_policy(struct inode *root, const char *text, size_t textlen,
const char *pkcs7, size_t pkcs7len);
int ipe_set_active_pol(const struct ipe_policy *p);
extern struct mutex ipe_policy_lock;
#endif /* _IPE_POLICY_H */