linux-stable/include/linux/ima.h
Roberto Sassu 5d1ef2ce13 ima: Introduce ima_get_current_hash_algo()
Buffer measurements, unlike file measurements, are not accessible after the
measurement is done, as buffers are not suitable for use with the
integrity_iint_cache structure (there is no index, for files it is the
inode number). In the subsequent patches, the measurement (digest) will be
returned directly by the functions that perform the buffer measurement,
ima_measure_critical_data() and process_buffer_measurement().

A caller of those functions also needs to know the algorithm used to
calculate the digest. Instead of adding the algorithm as a new parameter to
the functions, this patch provides it separately with the new function
ima_get_current_hash_algo().

Since the hash algorithm does not change after the IMA setup phase, there
is no risk of races (obtaining a digest calculated with a different
algorithm than the one returned).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
[zohar@linux.ibm.com: annotate ima_hash_algo as __ro_after_init]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-07-23 09:25:28 -04:00

217 lines
5.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2008 IBM Corporation
* Author: Mimi Zohar <zohar@us.ibm.com>
*/
#ifndef _LINUX_IMA_H
#define _LINUX_IMA_H
#include <linux/kernel_read_file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
#include <crypto/hash_info.h>
struct linux_binprm;
#ifdef CONFIG_IMA
extern enum hash_algo ima_get_current_hash_algo(void);
extern int ima_bprm_check(struct linux_binprm *bprm);
extern int ima_file_check(struct file *file, int mask);
extern void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
struct inode *inode);
extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot);
extern int ima_load_data(enum kernel_load_data_id id, bool contents);
extern int ima_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id id, char *description);
extern int ima_read_file(struct file *file, enum kernel_read_file_id id,
bool contents);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
extern void ima_post_path_mknod(struct user_namespace *mnt_userns,
struct dentry *dentry);
extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
extern void ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
bool hash);
#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM
extern void ima_appraise_parse_cmdline(void);
#else
static inline void ima_appraise_parse_cmdline(void) {}
#endif
#ifdef CONFIG_IMA_KEXEC
extern void ima_add_kexec_buffer(struct kimage *image);
#endif
#ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
extern bool arch_ima_get_secureboot(void);
extern const char * const *arch_get_ima_policy(void);
#else
static inline bool arch_ima_get_secureboot(void)
{
return false;
}
static inline const char * const *arch_get_ima_policy(void)
{
return NULL;
}
#endif
#else
static inline enum hash_algo ima_get_current_hash_algo(void)
{
return HASH_ALGO__LAST;
}
static inline int ima_bprm_check(struct linux_binprm *bprm)
{
return 0;
}
static inline int ima_file_check(struct file *file, int mask)
{
return 0;
}
static inline void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
struct inode *inode)
{
}
static inline void ima_file_free(struct file *file)
{
return;
}
static inline int ima_file_mmap(struct file *file, unsigned long prot)
{
return 0;
}
static inline int ima_file_mprotect(struct vm_area_struct *vma,
unsigned long prot)
{
return 0;
}
static inline int ima_load_data(enum kernel_load_data_id id, bool contents)
{
return 0;
}
static inline int ima_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id id,
char *description)
{
return 0;
}
static inline int ima_read_file(struct file *file, enum kernel_read_file_id id,
bool contents)
{
return 0;
}
static inline int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id)
{
return 0;
}
static inline void ima_post_path_mknod(struct user_namespace *mnt_userns,
struct dentry *dentry)
{
return;
}
static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size)
{
return -EOPNOTSUPP;
}
static inline int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
{
return -EOPNOTSUPP;
}
static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {}
static inline void ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
bool hash) {}
#endif /* CONFIG_IMA */
#ifndef CONFIG_IMA_KEXEC
struct kimage;
static inline void ima_add_kexec_buffer(struct kimage *image)
{}
#endif
#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
extern void ima_post_key_create_or_update(struct key *keyring,
struct key *key,
const void *payload, size_t plen,
unsigned long flags, bool create);
#else
static inline void ima_post_key_create_or_update(struct key *keyring,
struct key *key,
const void *payload,
size_t plen,
unsigned long flags,
bool create) {}
#endif /* CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS */
#ifdef CONFIG_IMA_APPRAISE
extern bool is_ima_appraise_enabled(void);
extern void ima_inode_post_setattr(struct user_namespace *mnt_userns,
struct dentry *dentry);
extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
const void *xattr_value, size_t xattr_value_len);
extern int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name);
#else
static inline bool is_ima_appraise_enabled(void)
{
return 0;
}
static inline void ima_inode_post_setattr(struct user_namespace *mnt_userns,
struct dentry *dentry)
{
return;
}
static inline int ima_inode_setxattr(struct dentry *dentry,
const char *xattr_name,
const void *xattr_value,
size_t xattr_value_len)
{
return 0;
}
static inline int ima_inode_removexattr(struct dentry *dentry,
const char *xattr_name)
{
return 0;
}
#endif /* CONFIG_IMA_APPRAISE */
#if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
extern bool ima_appraise_signature(enum kernel_read_file_id func);
#else
static inline bool ima_appraise_signature(enum kernel_read_file_id func)
{
return false;
}
#endif /* CONFIG_IMA_APPRAISE && CONFIG_INTEGRITY_TRUSTED_KEYRING */
#endif /* _LINUX_IMA_H */