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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 | ||
5ac8c355 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 | 76 | int error = -ENOMEM; |
5ac8c355 | 77 | __le32 le32_version = cpu_to_le32(version); |
f8eb8a13 | 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) |
94 | goto fail; | |
71ac7f62 | 95 | error = crypto_shash_update(&desc.shash, (u8 *) &le32_version, 4); |
f8eb8a13 JJ |
96 | if (error) |
97 | goto fail; | |
71ac7f62 | 98 | error = crypto_shash_update(&desc.shash, (u8 *) start, len); |
f8eb8a13 JJ |
99 | if (error) |
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); |