1 /*
2 * Cryptographic API.
3 *
4 * Cipher operations.
5 *
6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
7 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
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 <crypto/algapi.h>
17 #include <linux/kernel.h>
18 #include <linux/crypto.h>
19 #include <linux/errno.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include "internal.h"
23
setkey_unaligned(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)24 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
25 unsigned int keylen)
26 {
27 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
28 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
29 int ret;
30 u8 *buffer, *alignbuffer;
31 unsigned long absize;
32
33 absize = keylen + alignmask;
34 buffer = kmalloc(absize, GFP_ATOMIC);
35 if (!buffer)
36 return -ENOMEM;
37
38 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
39 memcpy(alignbuffer, key, keylen);
40 ret = cia->cia_setkey(tfm, alignbuffer, keylen);
41 memset(alignbuffer, 0, keylen);
42 kfree(buffer);
43 return ret;
44
45 }
46
setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)47 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
48 {
49 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
50 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
51
52 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
53 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
54 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
55 return -EINVAL;
56 }
57
58 if ((unsigned long)key & alignmask)
59 return setkey_unaligned(tfm, key, keylen);
60
61 return cia->cia_setkey(tfm, key, keylen);
62 }
63
cipher_crypt_unaligned(void (* fn)(struct crypto_tfm *,u8 *,const u8 *),struct crypto_tfm * tfm,u8 * dst,const u8 * src)64 static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
65 const u8 *),
66 struct crypto_tfm *tfm,
67 u8 *dst, const u8 *src)
68 {
69 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
70 unsigned int size = crypto_tfm_alg_blocksize(tfm);
71 u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
72 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
73
74 memcpy(tmp, src, size);
75 fn(tfm, tmp, tmp);
76 memcpy(dst, tmp, size);
77 }
78
cipher_encrypt_unaligned(struct crypto_tfm * tfm,u8 * dst,const u8 * src)79 static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
80 u8 *dst, const u8 *src)
81 {
82 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
83 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
84
85 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
86 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
87 return;
88 }
89
90 cipher->cia_encrypt(tfm, dst, src);
91 }
92
cipher_decrypt_unaligned(struct crypto_tfm * tfm,u8 * dst,const u8 * src)93 static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
94 u8 *dst, const u8 *src)
95 {
96 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
97 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
98
99 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
100 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
101 return;
102 }
103
104 cipher->cia_decrypt(tfm, dst, src);
105 }
106
crypto_init_cipher_ops(struct crypto_tfm * tfm)107 int crypto_init_cipher_ops(struct crypto_tfm *tfm)
108 {
109 struct cipher_tfm *ops = &tfm->crt_cipher;
110 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
111
112 ops->cit_setkey = setkey;
113 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
114 cipher_encrypt_unaligned : cipher->cia_encrypt;
115 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
116 cipher_decrypt_unaligned : cipher->cia_decrypt;
117
118 return 0;
119 }
120