Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
23static 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
45static 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
56static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
57 u32 mask)
58{
59 return alg->cra_ctxsize;
60}
61
62static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
63{
64 struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
65 struct aead_tfm *crt = &tfm->crt_aead;
66
67 if (max(alg->authsize, alg->ivsize) > PAGE_SIZE / 8)
68 return -EINVAL;
69
70 crt->setkey = setkey;
71 crt->encrypt = alg->encrypt;
72 crt->decrypt = alg->decrypt;
73 crt->ivsize = alg->ivsize;
74 crt->authsize = alg->authsize;
75
76 return 0;
77}
78
79static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
80 __attribute__ ((unused));
81static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
82{
83 struct aead_alg *aead = &alg->cra_aead;
84
85 seq_printf(m, "type : aead\n");
86 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
87 seq_printf(m, "ivsize : %u\n", aead->ivsize);
88 seq_printf(m, "authsize : %u\n", aead->authsize);
89}
90
91const struct crypto_type crypto_aead_type = {
92 .ctxsize = crypto_aead_ctxsize,
93 .init = crypto_init_aead_ops,
94#ifdef CONFIG_PROC_FS
95 .show = crypto_aead_show,
96#endif
97};
98EXPORT_SYMBOL_GPL(crypto_aead_type);
99
100MODULE_LICENSE("GPL");
101MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");