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1ae97820 HX |
1 | /* |
2 | * AEAD: Authenticated Encryption with Associated Data | |
3 | * | |
4 | * This file provides API support for AEAD algorithms. | |
5 | * | |
6 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2 of the License, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include <crypto/algapi.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/seq_file.h> | |
22 | ||
23 | static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key, | |
24 | unsigned int keylen) | |
25 | { | |
26 | struct aead_alg *aead = crypto_aead_alg(tfm); | |
27 | unsigned long alignmask = crypto_aead_alignmask(tfm); | |
28 | int ret; | |
29 | u8 *buffer, *alignbuffer; | |
30 | unsigned long absize; | |
31 | ||
32 | absize = keylen + alignmask; | |
33 | buffer = kmalloc(absize, GFP_ATOMIC); | |
34 | if (!buffer) | |
35 | return -ENOMEM; | |
36 | ||
37 | alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); | |
38 | memcpy(alignbuffer, key, keylen); | |
39 | ret = aead->setkey(tfm, alignbuffer, keylen); | |
40 | memset(alignbuffer, 0, keylen); | |
41 | kfree(buffer); | |
42 | return ret; | |
43 | } | |
44 | ||
45 | static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen) | |
46 | { | |
47 | struct aead_alg *aead = crypto_aead_alg(tfm); | |
48 | unsigned long alignmask = crypto_aead_alignmask(tfm); | |
49 | ||
50 | if ((unsigned long)key & alignmask) | |
51 | return setkey_unaligned(tfm, key, keylen); | |
52 | ||
53 | return aead->setkey(tfm, key, keylen); | |
54 | } | |
55 | ||
7ba683a6 HX |
56 | int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize) |
57 | { | |
58 | int err; | |
59 | ||
60 | if (authsize > crypto_aead_alg(tfm)->maxauthsize) | |
61 | return -EINVAL; | |
62 | ||
63 | if (crypto_aead_alg(tfm)->setauthsize) { | |
64 | err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize); | |
65 | if (err) | |
66 | return err; | |
67 | } | |
68 | ||
69 | crypto_aead_crt(tfm)->authsize = authsize; | |
70 | return 0; | |
71 | } | |
72 | EXPORT_SYMBOL_GPL(crypto_aead_setauthsize); | |
73 | ||
1ae97820 HX |
74 | static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type, |
75 | u32 mask) | |
76 | { | |
77 | return alg->cra_ctxsize; | |
78 | } | |
79 | ||
80 | static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask) | |
81 | { | |
82 | struct aead_alg *alg = &tfm->__crt_alg->cra_aead; | |
83 | struct aead_tfm *crt = &tfm->crt_aead; | |
84 | ||
7ba683a6 | 85 | if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8) |
1ae97820 HX |
86 | return -EINVAL; |
87 | ||
88 | crt->setkey = setkey; | |
89 | crt->encrypt = alg->encrypt; | |
90 | crt->decrypt = alg->decrypt; | |
91 | crt->ivsize = alg->ivsize; | |
7ba683a6 | 92 | crt->authsize = alg->maxauthsize; |
1ae97820 HX |
93 | |
94 | return 0; | |
95 | } | |
96 | ||
97 | static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg) | |
98 | __attribute__ ((unused)); | |
99 | static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg) | |
100 | { | |
101 | struct aead_alg *aead = &alg->cra_aead; | |
102 | ||
103 | seq_printf(m, "type : aead\n"); | |
104 | seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); | |
105 | seq_printf(m, "ivsize : %u\n", aead->ivsize); | |
7ba683a6 | 106 | seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize); |
1ae97820 HX |
107 | } |
108 | ||
109 | const struct crypto_type crypto_aead_type = { | |
110 | .ctxsize = crypto_aead_ctxsize, | |
111 | .init = crypto_init_aead_ops, | |
112 | #ifdef CONFIG_PROC_FS | |
113 | .show = crypto_aead_show, | |
114 | #endif | |
115 | }; | |
116 | EXPORT_SYMBOL_GPL(crypto_aead_type); | |
117 | ||
118 | MODULE_LICENSE("GPL"); | |
119 | MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)"); |