linux/security/integrity/evm/evm.h
Roberto Sassu c31288e56c evm: Support multiple LSMs providing an xattr
Currently, evm_inode_init_security() processes a single LSM xattr from the
array passed by security_inode_init_security(), and calculates the HMAC on
it and other inode metadata.

As the LSM infrastructure now can pass to EVM an array with multiple
xattrs, scan them until the terminator (xattr name NULL), and calculate the
HMAC on all of them.

Also, double check that the xattrs array terminator is the first non-filled
slot (obtained with lsm_get_xattr_slot()). Consumers of the xattrs array,
such as the initxattrs() callbacks, rely on the terminator.

Finally, change the name of the lsm_xattr parameter of evm_init_hmac() to
xattrs, to reflect the new type of information passed.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-10 13:59:39 -04:00

68 lines
1.7 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;
};
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;
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);
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);
int evm_init_hmac(struct inode *inode, const struct xattr *xattrs,
char *hmac_val);
int evm_init_secfs(void);
#endif