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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Cryptographic API.
3 *
4 * Cipher operations.
5 *
6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
Herbert Xuc774e932005-07-06 13:51:31 -07007 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
Richard Hartmannd150975b2010-02-16 20:31:37 +080011 * Software Foundation; either version 2 of the License, or (at your option)
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * any later version.
13 *
14 */
Herbert Xuf1ddcaf2007-01-27 10:05:15 +110015
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/kernel.h>
17#include <linux/crypto.h>
18#include <linux/errno.h>
Herbert Xu791b4d52007-08-23 16:23:01 +080019#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
Herbert Xu791b4d52007-08-23 16:23:01 +080023static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
24 unsigned int keylen)
Sebastian Siewiorca7c3932007-05-19 19:51:21 +100025{
26 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
27 unsigned long alignmask = crypto_tfm_alg_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 = cia->cia_setkey(tfm, alignbuffer, keylen);
Sebastian Siewior06817172007-08-03 20:33:47 +080040 memset(alignbuffer, 0, keylen);
Sebastian Siewiorca7c3932007-05-19 19:51:21 +100041 kfree(buffer);
42 return ret;
43
44}
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
47{
48 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
Sebastian Siewiorca7c3932007-05-19 19:51:21 +100049 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
50
Herbert Xu560c06a2006-08-13 14:16:39 +100051 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
53 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
54 return -EINVAL;
Sebastian Siewiorca7c3932007-05-19 19:51:21 +100055 }
56
57 if ((unsigned long)key & alignmask)
58 return setkey_unaligned(tfm, key, keylen);
59
60 return cia->cia_setkey(tfm, key, keylen);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061}
62
Herbert Xuf28776a2006-08-13 20:58:18 +100063static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
64 const u8 *),
65 struct crypto_tfm *tfm,
66 u8 *dst, const u8 *src)
67{
68 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
69 unsigned int size = crypto_tfm_alg_blocksize(tfm);
70 u8 buffer[size + alignmask];
71 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
72
73 memcpy(tmp, src, size);
74 fn(tfm, tmp, tmp);
75 memcpy(dst, tmp, size);
76}
77
78static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
79 u8 *dst, const u8 *src)
80{
81 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
82 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
83
84 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
85 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
86 return;
87 }
88
89 cipher->cia_encrypt(tfm, dst, src);
90}
91
92static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
93 u8 *dst, const u8 *src)
94{
95 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
96 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
97
98 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
99 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
100 return;
101 }
102
103 cipher->cia_decrypt(tfm, dst, src);
104}
105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106int crypto_init_cipher_ops(struct crypto_tfm *tfm)
107{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 struct cipher_tfm *ops = &tfm->crt_cipher;
Herbert Xuf28776a2006-08-13 20:58:18 +1000109 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111 ops->cit_setkey = setkey;
Herbert Xuf28776a2006-08-13 20:58:18 +1000112 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
113 cipher_encrypt_unaligned : cipher->cia_encrypt;
114 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
115 cipher_decrypt_unaligned : cipher->cia_decrypt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100117 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118}