[mirror_ubuntu-bionic-kernel.git] / security / apparmor / crypto.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);
Commit	Line	Data
f8eb8a13 JJ	1	/*
	2	* AppArmor security module
	3	*
	4	* This file contains AppArmor policy loading interface function definitions.
	5	*
	6	* Copyright 2013 Canonical Ltd.
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License as
	10	* published by the Free Software Foundation, version 2 of the
	11	* License.
	12	*
	13	* Fns to provide a checksum of policy that has been loaded this can be
	14	* compared to userspace policy compiles to check loaded policy is what
	15	* it should be.
	16	*/
	17
71ac7f62	18	#include <crypto/hash.h>
f8eb8a13 JJ	19
	20	#include "include/apparmor.h"
	21	#include "include/crypto.h"
	22
	23	static unsigned int apparmor_hash_size;
	24
71ac7f62	25	static struct crypto_shash *apparmor_tfm;
f8eb8a13 JJ	26
	27	unsigned int aa_hash_size(void)
	28	{
	29	return apparmor_hash_size;
	30	}
	31
5ac8c355 JJ	32	char aa_calc_hash(void data, size_t len)
5ac8c355 JJ	33	{
9814448d	34	SHASH_DESC_ON_STACK(desc, apparmor_tfm);
5ac8c355 JJ	35	char *hash = NULL;
	36	int error = -ENOMEM;
	37
	38	if (!apparmor_tfm)
	39	return NULL;
	40
	41	hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
	42	if (!hash)
	43	goto fail;
	44
9814448d NI	45	desc->tfm = apparmor_tfm;
9814448d NI	46	desc->flags = 0;
5ac8c355	47
9814448d	48	error = crypto_shash_init(desc);
5ac8c355 JJ	49	if (error)
5ac8c355 JJ	50	goto fail;
9814448d	51	error = crypto_shash_update(desc, (u8 *) data, len);
5ac8c355 JJ	52	if (error)
5ac8c355 JJ	53	goto fail;
9814448d	54	error = crypto_shash_final(desc, hash);
5ac8c355 JJ	55	if (error)
	56	goto fail;
	57
	58	return hash;
	59
	60	fail:
	61	kfree(hash);
	62
	63	return ERR_PTR(error);
	64	}
	65
f8eb8a13 JJ	66	int aa_calc_profile_hash(struct aa_profile profile, u32 version, void start,
	67	size_t len)
	68	{
9814448d	69	SHASH_DESC_ON_STACK(desc, apparmor_tfm);
f8eb8a13	70	int error = -ENOMEM;
5ac8c355	71	__le32 le32_version = cpu_to_le32(version);
f8eb8a13	72
7616ac70 AB	73	if (!aa_g_hash_policy)
	74	return 0;
	75
f8eb8a13 JJ	76	if (!apparmor_tfm)
	77	return 0;
	78
f8eb8a13 JJ	79	profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
	80	if (!profile->hash)
	81	goto fail;
	82
9814448d NI	83	desc->tfm = apparmor_tfm;
9814448d NI	84	desc->flags = 0;
71ac7f62	85
9814448d	86	error = crypto_shash_init(desc);
f8eb8a13 JJ	87	if (error)
f8eb8a13 JJ	88	goto fail;
9814448d	89	error = crypto_shash_update(desc, (u8 *) &le32_version, 4);
f8eb8a13 JJ	90	if (error)
f8eb8a13 JJ	91	goto fail;
9814448d	92	error = crypto_shash_update(desc, (u8 *) start, len);
f8eb8a13 JJ	93	if (error)
f8eb8a13 JJ	94	goto fail;
9814448d	95	error = crypto_shash_final(desc, profile->hash);
f8eb8a13 JJ	96	if (error)
	97	goto fail;
	98
	99	return 0;
	100
	101	fail:
	102	kfree(profile->hash);
	103	profile->hash = NULL;
	104
	105	return error;
	106	}
	107
	108	static int __init init_profile_hash(void)
	109	{
71ac7f62	110	struct crypto_shash *tfm;
f8eb8a13 JJ	111
	112	if (!apparmor_initialized)
	113	return 0;
	114
71ac7f62	115	tfm = crypto_alloc_shash("sha1", 0, CRYPTO_ALG_ASYNC);
f8eb8a13 JJ	116	if (IS_ERR(tfm)) {
	117	int error = PTR_ERR(tfm);
	118	AA_ERROR("failed to setup profile sha1 hashing: %d\n", error);
	119	return error;
	120	}
	121	apparmor_tfm = tfm;
71ac7f62	122	apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm);
f8eb8a13 JJ	123
	124	aa_info_message("AppArmor sha1 policy hashing enabled");
	125
	126	return 0;
	127	}
	128
	129	late_initcall(init_profile_hash);