evm.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2005-2010 IBM Corporation
 *
 * Authors:
 * Mimi Zohar <[email protected]>
 * Kylene Hall <[email protected]>
 *
 * 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