projects/linux·blob v2.6.34 · refs

122 lines · 3.3 KiB

1/*
2 * Cryptographic API.
3 *
4 * Cipher operations.
5 *
6 * Copyright (c) 2002 James Morris <[email protected]>
7 * Copyright (c) 2005 Herbert Xu <[email protected]>
8 *
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
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 */
15
16#include <linux/kernel.h>
17#include <linux/crypto.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/string.h>
21#include "internal.h"
22
23static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
24 unsigned int keylen)
25{
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);
40 memset(alignbuffer, 0, keylen);
41 kfree(buffer);
42 return ret;
43
44}
45
46static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
47{
48 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
49 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
50
51 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
52 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
53 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
54 return -EINVAL;
55 }
56
57 if ((unsigned long)key & alignmask)
58 return setkey_unaligned(tfm, key, keylen);
59
60 return cia->cia_setkey(tfm, key, keylen);
61}
62
63static 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
106int crypto_init_cipher_ops(struct crypto_tfm *tfm)
107{
108 struct cipher_tfm *ops = &tfm->crt_cipher;
109 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
110
111 ops->cit_setkey = setkey;
112 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;
116
117 return 0;
118}
119
120void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
121{
122}