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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
f8eb8a13 JJ |
2 | /* |
3 | * AppArmor security module | |
4 | * | |
5 | * This file contains AppArmor policy loading interface function definitions. | |
6 | * | |
7 | * Copyright 2013 Canonical Ltd. | |
8 | * | |
f8eb8a13 JJ |
9 | * Fns to provide a checksum of policy that has been loaded this can be |
10 | * compared to userspace policy compiles to check loaded policy is what | |
11 | * it should be. | |
12 | */ | |
13 | ||
71ac7f62 | 14 | #include <crypto/hash.h> |
f8eb8a13 JJ |
15 | |
16 | #include "include/apparmor.h" | |
17 | #include "include/crypto.h" | |
18 | ||
19 | static unsigned int apparmor_hash_size; | |
20 | ||
71ac7f62 | 21 | static struct crypto_shash *apparmor_tfm; |
f8eb8a13 JJ |
22 | |
23 | unsigned int aa_hash_size(void) | |
24 | { | |
25 | return apparmor_hash_size; | |
26 | } | |
27 | ||
c7cf8aae JJ |
28 | void aa_snprint_hashstr(char *out, unsigned char *hash, unsigned int hsize) |
29 | { | |
30 | unsigned int i; | |
31 | ||
32 | for (i = 0; i < hsize; i++) | |
33 | sprintf(out + i*2, "%.2x", hash[i]); | |
34 | out[hsize*2] = 0; | |
35 | } | |
36 | ||
37 | char *aa_asprint_hashstr(unsigned char *hash, unsigned int hsize, gfp_t gfp) | |
38 | { | |
39 | char *buffer = kmalloc(hsize*2 + 1, gfp); | |
40 | if (!buffer) | |
41 | return NULL; | |
42 | aa_snprint_hashstr(buffer, hash, hsize); | |
43 | ||
44 | return buffer; | |
45 | } | |
46 | ||
5ac8c355 JJ |
47 | char *aa_calc_hash(void *data, size_t len) |
48 | { | |
9814448d | 49 | SHASH_DESC_ON_STACK(desc, apparmor_tfm); |
5ac8c355 JJ |
50 | char *hash = NULL; |
51 | int error = -ENOMEM; | |
52 | ||
53 | if (!apparmor_tfm) | |
54 | return NULL; | |
55 | ||
56 | hash = kzalloc(apparmor_hash_size, GFP_KERNEL); | |
57 | if (!hash) | |
58 | goto fail; | |
59 | ||
9814448d | 60 | desc->tfm = apparmor_tfm; |
5ac8c355 | 61 | |
9814448d | 62 | error = crypto_shash_init(desc); |
5ac8c355 JJ |
63 | if (error) |
64 | goto fail; | |
9814448d | 65 | error = crypto_shash_update(desc, (u8 *) data, len); |
5ac8c355 JJ |
66 | if (error) |
67 | goto fail; | |
9814448d | 68 | error = crypto_shash_final(desc, hash); |
5ac8c355 JJ |
69 | if (error) |
70 | goto fail; | |
71 | ||
72 | return hash; | |
73 | ||
74 | fail: | |
75 | kfree(hash); | |
76 | ||
77 | return ERR_PTR(error); | |
78 | } | |
79 | ||
f8eb8a13 JJ |
80 | int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, |
81 | size_t len) | |
82 | { | |
9814448d | 83 | SHASH_DESC_ON_STACK(desc, apparmor_tfm); |
f8eb8a13 | 84 | int error = -ENOMEM; |
5ac8c355 | 85 | __le32 le32_version = cpu_to_le32(version); |
f8eb8a13 | 86 | |
7616ac70 AB |
87 | if (!aa_g_hash_policy) |
88 | return 0; | |
89 | ||
f8eb8a13 JJ |
90 | if (!apparmor_tfm) |
91 | return 0; | |
92 | ||
f8eb8a13 JJ |
93 | profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL); |
94 | if (!profile->hash) | |
95 | goto fail; | |
96 | ||
9814448d | 97 | desc->tfm = apparmor_tfm; |
71ac7f62 | 98 | |
9814448d | 99 | error = crypto_shash_init(desc); |
f8eb8a13 JJ |
100 | if (error) |
101 | goto fail; | |
9814448d | 102 | error = crypto_shash_update(desc, (u8 *) &le32_version, 4); |
f8eb8a13 JJ |
103 | if (error) |
104 | goto fail; | |
9814448d | 105 | error = crypto_shash_update(desc, (u8 *) start, len); |
f8eb8a13 JJ |
106 | if (error) |
107 | goto fail; | |
9814448d | 108 | error = crypto_shash_final(desc, profile->hash); |
f8eb8a13 JJ |
109 | if (error) |
110 | goto fail; | |
111 | ||
112 | return 0; | |
113 | ||
114 | fail: | |
115 | kfree(profile->hash); | |
116 | profile->hash = NULL; | |
117 | ||
118 | return error; | |
119 | } | |
120 | ||
121 | static int __init init_profile_hash(void) | |
122 | { | |
71ac7f62 | 123 | struct crypto_shash *tfm; |
f8eb8a13 JJ |
124 | |
125 | if (!apparmor_initialized) | |
126 | return 0; | |
127 | ||
3d234b33 | 128 | tfm = crypto_alloc_shash("sha1", 0, 0); |
f8eb8a13 JJ |
129 | if (IS_ERR(tfm)) { |
130 | int error = PTR_ERR(tfm); | |
131 | AA_ERROR("failed to setup profile sha1 hashing: %d\n", error); | |
132 | return error; | |
133 | } | |
134 | apparmor_tfm = tfm; | |
71ac7f62 | 135 | apparmor_hash_size = crypto_shash_digestsize(apparmor_tfm); |
f8eb8a13 JJ |
136 | |
137 | aa_info_message("AppArmor sha1 policy hashing enabled"); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | late_initcall(init_profile_hash); |