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Commit | Line | Data |
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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 | ||
32 | int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, | |
33 | size_t len) | |
34 | { | |
71ac7f62 TH |
35 | struct { |
36 | struct shash_desc shash; | |
37 | char ctx[crypto_shash_descsize(apparmor_tfm)]; | |
38 | } desc; | |
f8eb8a13 JJ |
39 | int error = -ENOMEM; |
40 | u32 le32_version = cpu_to_le32(version); | |
41 | ||
7616ac70 AB |
42 | if (!aa_g_hash_policy) |
43 | return 0; | |
44 | ||
f8eb8a13 JJ |
45 | if (!apparmor_tfm) |
46 | return 0; | |
47 | ||
f8eb8a13 JJ |
48 | profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL); |
49 | if (!profile->hash) | |
50 | goto fail; | |
51 | ||
71ac7f62 TH |
52 | desc.shash.tfm = apparmor_tfm; |
53 | desc.shash.flags = 0; | |
54 | ||
55 | error = crypto_shash_init(&desc.shash); | |
f8eb8a13 JJ |
56 | if (error) |
57 | goto fail; | |
71ac7f62 | 58 | error = crypto_shash_update(&desc.shash, (u8 *) &le32_version, 4); |
f8eb8a13 JJ |
59 | if (error) |
60 | goto fail; | |
71ac7f62 | 61 | error = crypto_shash_update(&desc.shash, (u8 *) start, len); |
f8eb8a13 JJ |
62 | if (error) |
63 | goto fail; | |
71ac7f62 | 64 | error = crypto_shash_final(&desc.shash, profile->hash); |
f8eb8a13 JJ |
65 | if (error) |
66 | goto fail; | |
67 | ||
68 | return 0; | |
69 | ||
70 | fail: | |
71 | kfree(profile->hash); | |
72 | profile->hash = NULL; | |
73 | ||
74 | return error; | |
75 | } | |
76 | ||
77 | static int __init init_profile_hash(void) | |
78 | { | |
71ac7f62 | 79 | struct crypto_shash *tfm; |
f8eb8a13 JJ |
80 | |
81 | if (!apparmor_initialized) | |
82 | return 0; | |
83 | ||
71ac7f62 | 84 | tfm = crypto_alloc_shash("sha1", 0, CRYPTO_ALG_ASYNC); |
f8eb8a13 JJ |
85 | if (IS_ERR(tfm)) { |
86 | int error = PTR_ERR(tfm); | |
87 | AA_ERROR("failed to setup profile sha1 hashing: %d\n", error); | |
88 | return error; | |
89 | } | |
90 | apparmor_tfm = tfm; | |
71ac7f62 | 91 | apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm); |
f8eb8a13 JJ |
92 | |
93 | aa_info_message("AppArmor sha1 policy hashing enabled"); | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | late_initcall(init_profile_hash); |