130 lines
2.5 KiB
C
130 lines
2.5 KiB
C
/*
|
|
* AppArmor security module
|
|
*
|
|
* This file contains AppArmor policy loading interface function definitions.
|
|
*
|
|
* Copyright 2013 Canonical Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation, version 2 of the
|
|
* License.
|
|
*
|
|
* Fns to provide a checksum of policy that has been loaded this can be
|
|
* compared to userspace policy compiles to check loaded policy is what
|
|
* it should be.
|
|
*/
|
|
|
|
#include <crypto/hash.h>
|
|
|
|
#include "include/apparmor.h"
|
|
#include "include/crypto.h"
|
|
|
|
static unsigned int apparmor_hash_size;
|
|
|
|
static struct crypto_shash *apparmor_tfm;
|
|
|
|
unsigned int aa_hash_size(void)
|
|
{
|
|
return apparmor_hash_size;
|
|
}
|
|
|
|
char *aa_calc_hash(void *data, size_t len)
|
|
{
|
|
SHASH_DESC_ON_STACK(desc, apparmor_tfm);
|
|
char *hash = NULL;
|
|
int error = -ENOMEM;
|
|
|
|
if (!apparmor_tfm)
|
|
return NULL;
|
|
|
|
hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
|
|
if (!hash)
|
|
goto fail;
|
|
|
|
desc->tfm = apparmor_tfm;
|
|
desc->flags = 0;
|
|
|
|
error = crypto_shash_init(desc);
|
|
if (error)
|
|
goto fail;
|
|
error = crypto_shash_update(desc, (u8 *) data, len);
|
|
if (error)
|
|
goto fail;
|
|
error = crypto_shash_final(desc, hash);
|
|
if (error)
|
|
goto fail;
|
|
|
|
return hash;
|
|
|
|
fail:
|
|
kfree(hash);
|
|
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start,
|
|
size_t len)
|
|
{
|
|
SHASH_DESC_ON_STACK(desc, apparmor_tfm);
|
|
int error = -ENOMEM;
|
|
__le32 le32_version = cpu_to_le32(version);
|
|
|
|
if (!aa_g_hash_policy)
|
|
return 0;
|
|
|
|
if (!apparmor_tfm)
|
|
return 0;
|
|
|
|
profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
|
|
if (!profile->hash)
|
|
goto fail;
|
|
|
|
desc->tfm = apparmor_tfm;
|
|
desc->flags = 0;
|
|
|
|
error = crypto_shash_init(desc);
|
|
if (error)
|
|
goto fail;
|
|
error = crypto_shash_update(desc, (u8 *) &le32_version, 4);
|
|
if (error)
|
|
goto fail;
|
|
error = crypto_shash_update(desc, (u8 *) start, len);
|
|
if (error)
|
|
goto fail;
|
|
error = crypto_shash_final(desc, profile->hash);
|
|
if (error)
|
|
goto fail;
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
kfree(profile->hash);
|
|
profile->hash = NULL;
|
|
|
|
return error;
|
|
}
|
|
|
|
static int __init init_profile_hash(void)
|
|
{
|
|
struct crypto_shash *tfm;
|
|
|
|
if (!apparmor_initialized)
|
|
return 0;
|
|
|
|
tfm = crypto_alloc_shash("sha1", 0, CRYPTO_ALG_ASYNC);
|
|
if (IS_ERR(tfm)) {
|
|
int error = PTR_ERR(tfm);
|
|
AA_ERROR("failed to setup profile sha1 hashing: %d\n", error);
|
|
return error;
|
|
}
|
|
apparmor_tfm = tfm;
|
|
apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm);
|
|
|
|
aa_info_message("AppArmor sha1 policy hashing enabled");
|
|
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(init_profile_hash);
|