[mirror_ubuntu-zesty-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)
{
	struct {
		struct shash_desc shash;
		char ctx[crypto_shash_descsize(apparmor_tfm)];
	} desc;
	char *hash = NULL;
	int error = -ENOMEM;

	if (!apparmor_tfm)
		return NULL;

	hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
	if (!hash)
		goto fail;

	desc.shash.tfm = apparmor_tfm;
	desc.shash.flags = 0;

	error = crypto_shash_init(&desc.shash);
	if (error)
		goto fail;
	error = crypto_shash_update(&desc.shash, (u8 *) data, len);
	if (error)
		goto fail;
	error = crypto_shash_final(&desc.shash, 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)
{
	struct {
		struct shash_desc shash;
		char ctx[crypto_shash_descsize(apparmor_tfm)];
	} desc;
	int error = -ENOMEM;
	u32 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.shash.tfm = apparmor_tfm;
	desc.shash.flags = 0;

	error = crypto_shash_init(&desc.shash);
	if (error)
		goto fail;
	error = crypto_shash_update(&desc.shash, (u8 *) &le32_version, 4);
	if (error)
		goto fail;
	error = crypto_shash_update(&desc.shash, (u8 *) start, len);
	if (error)
		goto fail;
	error = crypto_shash_final(&desc.shash, 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
3b8ad847 JJ	32	char aa_calc_hash(void data, size_t len)
	33	{
	34	struct {
	35	struct shash_desc shash;
	36	char ctx[crypto_shash_descsize(apparmor_tfm)];
	37	} desc;
	38	char *hash = NULL;
	39	int error = -ENOMEM;
	40
	41	if (!apparmor_tfm)
	42	return NULL;
	43
	44	hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
	45	if (!hash)
	46	goto fail;
	47
	48	desc.shash.tfm = apparmor_tfm;
	49	desc.shash.flags = 0;
	50
	51	error = crypto_shash_init(&desc.shash);
	52	if (error)
	53	goto fail;
	54	error = crypto_shash_update(&desc.shash, (u8 *) data, len);
	55	if (error)
	56	goto fail;
	57	error = crypto_shash_final(&desc.shash, hash);
	58	if (error)
	59	goto fail;
	60
	61	return hash;
	62
	63	fail:
	64	kfree(hash);
	65
	66	return ERR_PTR(error);
	67	}
	68
f8eb8a13 JJ	69	int aa_calc_profile_hash(struct aa_profile profile, u32 version, void start,
	70	size_t len)
	71	{
71ac7f62 TH	72	struct {
	73	struct shash_desc shash;
	74	char ctx[crypto_shash_descsize(apparmor_tfm)];
	75	} desc;
f8eb8a13 JJ	76	int error = -ENOMEM;
	77	u32 le32_version = cpu_to_le32(version);
	78
7616ac70 AB	79	if (!aa_g_hash_policy)
	80	return 0;
	81
f8eb8a13 JJ	82	if (!apparmor_tfm)
	83	return 0;
	84
f8eb8a13 JJ	85	profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL);
	86	if (!profile->hash)
	87	goto fail;
	88
71ac7f62 TH	89	desc.shash.tfm = apparmor_tfm;
	90	desc.shash.flags = 0;
	91
	92	error = crypto_shash_init(&desc.shash);
f8eb8a13 JJ	93	if (error)
f8eb8a13 JJ	94	goto fail;
71ac7f62	95	error = crypto_shash_update(&desc.shash, (u8 *) &le32_version, 4);
f8eb8a13 JJ	96	if (error)
f8eb8a13 JJ	97	goto fail;
71ac7f62	98	error = crypto_shash_update(&desc.shash, (u8 *) start, len);
f8eb8a13 JJ	99	if (error)
f8eb8a13 JJ	100	goto fail;
71ac7f62	101	error = crypto_shash_final(&desc.shash, profile->hash);
f8eb8a13 JJ	102	if (error)
	103	goto fail;
	104
	105	return 0;
	106
	107	fail:
	108	kfree(profile->hash);
	109	profile->hash = NULL;
	110
	111	return error;
	112	}
	113
	114	static int __init init_profile_hash(void)
	115	{
71ac7f62	116	struct crypto_shash *tfm;
f8eb8a13 JJ	117
	118	if (!apparmor_initialized)
	119	return 0;
	120
71ac7f62	121	tfm = crypto_alloc_shash("sha1", 0, CRYPTO_ALG_ASYNC);
f8eb8a13 JJ	122	if (IS_ERR(tfm)) {
	123	int error = PTR_ERR(tfm);
	124	AA_ERROR("failed to setup profile sha1 hashing: %d\n", error);
	125	return error;
	126	}
	127	apparmor_tfm = tfm;
71ac7f62	128	apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm);
f8eb8a13 JJ	129
	130	aa_info_message("AppArmor sha1 policy hashing enabled");
	131
	132	return 0;
	133	}
	134
	135	late_initcall(init_profile_hash);