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 | { | |
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; |
46 | desc->flags = 0; | |
5ac8c355 | 47 | |
9814448d | 48 | error = crypto_shash_init(desc); |
5ac8c355 JJ |
49 | if (error) |
50 | goto fail; | |
9814448d | 51 | error = crypto_shash_update(desc, (u8 *) data, len); |
5ac8c355 JJ |
52 | if (error) |
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; |
84 | desc->flags = 0; | |
71ac7f62 | 85 | |
9814448d | 86 | error = crypto_shash_init(desc); |
f8eb8a13 JJ |
87 | if (error) |
88 | goto fail; | |
9814448d | 89 | error = crypto_shash_update(desc, (u8 *) &le32_version, 4); |
f8eb8a13 JJ |
90 | if (error) |
91 | goto fail; | |
9814448d | 92 | error = crypto_shash_update(desc, (u8 *) start, len); |
f8eb8a13 JJ |
93 | if (error) |
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 | ||
3d234b33 | 115 | tfm = crypto_alloc_shash("sha1", 0, 0); |
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); |