1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Cryptographic API.
4 *
5 * Cipher operations.
6 *
7 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
8 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
9 */
10
11 #include <crypto/algapi.h>
12 #include <linux/kernel.h>
13 #include <linux/crypto.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include "internal.h"
18
setkey_unaligned(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)19 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
20 unsigned int keylen)
21 {
22 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
23 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
24 int ret;
25 u8 *buffer, *alignbuffer;
26 unsigned long absize;
27
28 absize = keylen + alignmask;
29 buffer = kmalloc(absize, GFP_ATOMIC);
30 if (!buffer)
31 return -ENOMEM;
32
33 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
34 memcpy(alignbuffer, key, keylen);
35 ret = cia->cia_setkey(tfm, alignbuffer, keylen);
36 memset(alignbuffer, 0, keylen);
37 kfree(buffer);
38 return ret;
39
40 }
41
setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)42 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
43 {
44 struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
45 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
46
47 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
48 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
49 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
50 return -EINVAL;
51 }
52
53 if ((unsigned long)key & alignmask)
54 return setkey_unaligned(tfm, key, keylen);
55
56 return cia->cia_setkey(tfm, key, keylen);
57 }
58
cipher_crypt_unaligned(void (* fn)(struct crypto_tfm *,u8 *,const u8 *),struct crypto_tfm * tfm,u8 * dst,const u8 * src)59 static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
60 const u8 *),
61 struct crypto_tfm *tfm,
62 u8 *dst, const u8 *src)
63 {
64 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
65 unsigned int size = crypto_tfm_alg_blocksize(tfm);
66 u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
67 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
68
69 memcpy(tmp, src, size);
70 fn(tfm, tmp, tmp);
71 memcpy(dst, tmp, size);
72 }
73
cipher_encrypt_unaligned(struct crypto_tfm * tfm,u8 * dst,const u8 * src)74 static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
75 u8 *dst, const u8 *src)
76 {
77 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
78 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
79
80 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
81 cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
82 return;
83 }
84
85 cipher->cia_encrypt(tfm, dst, src);
86 }
87
cipher_decrypt_unaligned(struct crypto_tfm * tfm,u8 * dst,const u8 * src)88 static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
89 u8 *dst, const u8 *src)
90 {
91 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
92 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
93
94 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
95 cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
96 return;
97 }
98
99 cipher->cia_decrypt(tfm, dst, src);
100 }
101
crypto_init_cipher_ops(struct crypto_tfm * tfm)102 int crypto_init_cipher_ops(struct crypto_tfm *tfm)
103 {
104 struct cipher_tfm *ops = &tfm->crt_cipher;
105 struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
106
107 ops->cit_setkey = setkey;
108 ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
109 cipher_encrypt_unaligned : cipher->cia_encrypt;
110 ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
111 cipher_decrypt_unaligned : cipher->cia_decrypt;
112
113 return 0;
114 }
115