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
20static 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
43int 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}
57EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, CRYPTO_INTERNAL);
58
59static 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
80void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
81			       u8 *dst, const u8 *src)
82{
83	cipher_crypt_one(tfm, dst, src, true);
84}
85EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, CRYPTO_INTERNAL);
86
87void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
88			       u8 *dst, const u8 *src)
89{
90	cipher_crypt_one(tfm, dst, src, false);
91}
92EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, CRYPTO_INTERNAL);
93
94struct 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}
120EXPORT_SYMBOL_GPL(crypto_clone_cipher);
121