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authorHerbert Xu <herbert@gondor.apana.org.au>2007-08-30 03:36:14 -0400
committerDavid S. Miller <davem@sunset.davemloft.net>2007-10-10 19:55:39 -0400
commit1ae978208e2ee9ba1b01d309164bc5e590cd242d (patch)
tree89dac5bceddd383836de9a4da6cc7d381f374e3f /crypto/aead.c
parente2ee95b8c69e542d6afef3f6f38ea598cc146ba7 (diff)
[CRYPTO] api: Add aead crypto type
This patch adds crypto_aead which is the interface for AEAD (Authenticated Encryption with Associated Data) algorithms. AEAD algorithms perform authentication and encryption in one step. Traditionally users (such as IPsec) would use two different crypto algorithms to perform these. With AEAD this comes down to one algorithm and one operation. Of course if traditional algorithms were used we'd still be doing two operations underneath. However, real AEAD algorithms may allow the underlying operations to be optimised as well. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/aead.c')
-rw-r--r--crypto/aead.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/crypto/aead.c b/crypto/aead.c
new file mode 100644
index 000000000000..84a3501fb478
--- /dev/null
+++ b/crypto/aead.c
@@ -0,0 +1,101 @@
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)");