1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Cryptographic API.
4 *
5 * Single-block 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 <crypto/internal/cipher.h>
13 #include <linux/kernel.h>
14 #include <linux/crypto.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include "internal.h"
19
20 static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
21 unsigned int keylen)
22 {
23 struct cipher_alg *cia = crypto_cipher_alg(tfm);
24 unsigned long alignmask = crypto_cipher_alignmask(tfm);
25 int ret;
26 u8 *buffer, *alignbuffer;
27 unsigned long absize;
28
29 absize = keylen + alignmask;
30 buffer = kmalloc(absize, GFP_ATOMIC);
31 if (!buffer)
32 return -ENOMEM;
33
34 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
35 memcpy(alignbuffer, key, keylen);
36 ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
37 kfree_sensitive(buffer);
38 return ret;
39
40 }
41
42 int crypto_cipher_setkey(struct crypto_cipher *tfm,
43 const u8 *key, unsigned int keylen)
44 {
45 struct cipher_alg *cia = crypto_cipher_alg(tfm);
46 unsigned long alignmask = crypto_cipher_alignmask(tfm);
47
48 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
49 return -EINVAL;
50
51 if ((unsigned long)key & alignmask)
52 return setkey_unaligned(tfm, key, keylen);
53
54 return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
55 }
56 EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, CRYPTO_INTERNAL);
57
58 static inline void cipher_crypt_one(struct crypto_cipher *tfm,
59 u8 *dst, const u8 *src, bool enc)
60 {
61 unsigned long alignmask = crypto_cipher_alignmask(tfm);
62 struct cipher_alg *cia = crypto_cipher_alg(tfm);
63 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
64 enc ? cia->cia_encrypt : cia->cia_decrypt;
65
66 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
67 unsigned int bs = crypto_cipher_blocksize(tfm);
68 u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
69 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
70
71 memcpy(tmp, src, bs);
72 fn(crypto_cipher_tfm(tfm), tmp, tmp);
73 memcpy(dst, tmp, bs);
74 } else {
75 fn(crypto_cipher_tfm(tfm), dst, src);
76 }
77 }
78
79 void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
80 u8 *dst, const u8 *src)
81 {
82 cipher_crypt_one(tfm, dst, src, true);
83 }
84 EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, CRYPTO_INTERNAL);
85
86 void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
87 u8 *dst, const u8 *src)
88 {
89 cipher_crypt_one(tfm, dst, src, false);
90 }
91 EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, CRYPTO_INTERNAL);
92
93 struct crypto_cipher *crypto_clone_cipher(struct crypto_cipher *cipher)
94 {
95 struct crypto_tfm *tfm = crypto_cipher_tfm(cipher);
96 struct crypto_alg *alg = tfm->__crt_alg;
97 struct crypto_cipher *ncipher;
98 struct crypto_tfm *ntfm;
99
100 if (alg->cra_init)
101 return ERR_PTR(-ENOSYS);
102
103 if (unlikely(!crypto_mod_get(alg)))
104 return ERR_PTR(-ESTALE);
105
106 ntfm = __crypto_alloc_tfmgfp(alg, CRYPTO_ALG_TYPE_CIPHER,
107 CRYPTO_ALG_TYPE_MASK, GFP_ATOMIC);
108 if (IS_ERR(ntfm)) {
109 crypto_mod_put(alg);
110 return ERR_CAST(ntfm);
111 }
112
113 ntfm->crt_flags = tfm->crt_flags;
114
115 ncipher = __crypto_cipher_cast(ntfm);
116
117 return ncipher;
118 }
119 EXPORT_SYMBOL_GPL(crypto_clone_cipher);
120
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