1
linux/security/integrity/evm/evm.h
Stefan Berger a652aa5906 evm: Store and detect metadata inode attributes changes
On stacked filesystem the metadata inode may be different than the one
file data inode and therefore changes to it need to be detected
independently. Therefore, store the i_version, device number, and inode
number associated with the file metadata inode.

Implement a function to detect changes to the inode and if a change is
detected reset the evm_status. This function will be called by IMA when
IMA detects that the metadata inode is different from the file's inode.

Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-04-09 17:14:57 -04:00

89 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2005-2010 IBM Corporation
*
* Authors:
* Mimi Zohar <zohar@us.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
*
* File: evm.h
*/
#ifndef __INTEGRITY_EVM_H
#define __INTEGRITY_EVM_H
#include <linux/xattr.h>
#include <linux/security.h>
#include "../integrity.h"
#define EVM_INIT_HMAC 0x0001
#define EVM_INIT_X509 0x0002
#define EVM_ALLOW_METADATA_WRITES 0x0004
#define EVM_SETUP_COMPLETE 0x80000000 /* userland has signaled key load */
#define EVM_KEY_MASK (EVM_INIT_HMAC | EVM_INIT_X509)
#define EVM_INIT_MASK (EVM_INIT_HMAC | EVM_INIT_X509 | EVM_SETUP_COMPLETE | \
EVM_ALLOW_METADATA_WRITES)
struct xattr_list {
struct list_head list;
char *name;
bool enabled;
};
#define EVM_NEW_FILE 0x00000001
#define EVM_IMMUTABLE_DIGSIG 0x00000002
/* EVM integrity metadata associated with an inode */
struct evm_iint_cache {
unsigned long flags;
enum integrity_status evm_status:4;
struct integrity_inode_attributes metadata_inode;
};
extern struct lsm_blob_sizes evm_blob_sizes;
static inline struct evm_iint_cache *evm_iint_inode(const struct inode *inode)
{
if (unlikely(!inode->i_security))
return NULL;
return inode->i_security + evm_blob_sizes.lbs_inode;
}
extern int evm_initialized;
#define EVM_ATTR_FSUUID 0x0001
extern int evm_hmac_attrs;
/* List of EVM protected security xattrs */
extern struct list_head evm_config_xattrnames;
struct evm_digest {
struct ima_digest_data_hdr hdr;
char digest[IMA_MAX_DIGEST_SIZE];
} __packed;
int evm_protected_xattr(const char *req_xattr_name);
int evm_init_key(void);
int evm_update_evmxattr(struct dentry *dentry,
const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len);
int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len, struct evm_digest *data,
struct evm_iint_cache *iint);
int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
size_t req_xattr_value_len, char type,
struct evm_digest *data, struct evm_iint_cache *iint);
int evm_init_hmac(struct inode *inode, const struct xattr *xattrs,
char *hmac_val);
int evm_init_secfs(void);
#endif