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
setkey_unaligned(struct crypto_cipher * tfm,const u8 * key,unsigned int keylen)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 memset(alignbuffer, 0, keylen);
38 kfree(buffer);
39 return ret;
40
41 }
42
crypto_cipher_setkey(struct crypto_cipher * tfm,const u8 * key,unsigned int keylen)43 int crypto_cipher_setkey(struct crypto_cipher *tfm,
44 const u8 *key, unsigned int keylen)
45 {
46 struct cipher_alg *cia = crypto_cipher_alg(tfm);
47 unsigned long alignmask = crypto_cipher_alignmask(tfm);
48
49 if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
50 return -EINVAL;
51
52 if ((unsigned long)key & alignmask)
53 return setkey_unaligned(tfm, key, keylen);
54
55 return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
56 }
57 EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, CRYPTO_INTERNAL);
58
cipher_crypt_one(struct crypto_cipher * tfm,u8 * dst,const u8 * src,bool enc)59 static inline void cipher_crypt_one(struct crypto_cipher *tfm,
60 u8 *dst, const u8 *src, bool enc)
61 {
62 unsigned long alignmask = crypto_cipher_alignmask(tfm);
63 struct cipher_alg *cia = crypto_cipher_alg(tfm);
64 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
65 enc ? cia->cia_encrypt : cia->cia_decrypt;
66
67 if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
68 unsigned int bs = crypto_cipher_blocksize(tfm);
69 u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
70 u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
71
72 memcpy(tmp, src, bs);
73 fn(crypto_cipher_tfm(tfm), tmp, tmp);
74 memcpy(dst, tmp, bs);
75 } else {
76 fn(crypto_cipher_tfm(tfm), dst, src);
77 }
78 }
79
crypto_cipher_encrypt_one(struct crypto_cipher * tfm,u8 * dst,const u8 * src)80 void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
81 u8 *dst, const u8 *src)
82 {
83 cipher_crypt_one(tfm, dst, src, true);
84 }
85 EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, CRYPTO_INTERNAL);
86
crypto_cipher_decrypt_one(struct crypto_cipher * tfm,u8 * dst,const u8 * src)87 void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
88 u8 *dst, const u8 *src)
89 {
90 cipher_crypt_one(tfm, dst, src, false);
91 }
92 EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, CRYPTO_INTERNAL);
93
crypto_clone_cipher(struct crypto_cipher * cipher)94 struct crypto_cipher *crypto_clone_cipher(struct crypto_cipher *cipher)
95 {
96 struct crypto_tfm *tfm = crypto_cipher_tfm(cipher);
97 struct crypto_alg *alg = tfm->__crt_alg;
98 struct crypto_cipher *ncipher;
99 struct crypto_tfm *ntfm;
100
101 if (alg->cra_init)
102 return ERR_PTR(-ENOSYS);
103
104 if (unlikely(!crypto_mod_get(alg)))
105 return ERR_PTR(-ESTALE);
106
107 ntfm = __crypto_alloc_tfmgfp(alg, CRYPTO_ALG_TYPE_CIPHER,
108 CRYPTO_ALG_TYPE_MASK, GFP_ATOMIC);
109 if (IS_ERR(ntfm)) {
110 crypto_mod_put(alg);
111 return ERR_CAST(ntfm);
112 }
113
114 ntfm->crt_flags = tfm->crt_flags;
115
116 ncipher = __crypto_cipher_cast(ntfm);
117
118 return ncipher;
119 }
120 EXPORT_SYMBOL_GPL(crypto_clone_cipher);
121