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 <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
setkey_unaligned(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)23 static 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
setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)46 static 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
cipher_crypt_unaligned(void (* fn)(struct crypto_tfm *,u8 *,const u8 *),struct crypto_tfm * tfm,u8 * dst,const u8 * src)63 static 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
cipher_encrypt_unaligned(struct crypto_tfm * tfm,u8 * dst,const u8 * src)78 static 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
cipher_decrypt_unaligned(struct crypto_tfm * tfm,u8 * dst,const u8 * src)92 static 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
crypto_init_cipher_ops(struct crypto_tfm * tfm)106 int 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
crypto_exit_cipher_ops(struct crypto_tfm * tfm)120 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
121 {
122 }
123