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cipher.c
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cipher.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Cryptographic API.
*
* Single-block cipher operations.
*
* Copyright (c) 2002 James Morris <[email protected]>
* Copyright (c) 2005 Herbert Xu <[email protected]>
*/
#include <crypto/algapi.h>
#include <crypto/internal/cipher.h>
#include <linux/kernel.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "internal.h"
static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
unsigned int keylen)
{
struct cipher_alg *cia = crypto_cipher_alg(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm);
int ret;
u8 *buffer, *alignbuffer;
unsigned long absize;
absize = keylen + alignmask;
buffer = kmalloc(absize, GFP_ATOMIC);
if (!buffer)
return -ENOMEM;
alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
int crypto_cipher_setkey(struct crypto_cipher *tfm,
const u8 *key, unsigned int keylen)
{
struct cipher_alg *cia = crypto_cipher_alg(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm);
if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
return -EINVAL;
if ((unsigned long)key & alignmask)
return setkey_unaligned(tfm, key, keylen);
return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
}
EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, CRYPTO_INTERNAL);
static inline void cipher_crypt_one(struct crypto_cipher *tfm,
u8 *dst, const u8 *src, bool enc)
{
unsigned long alignmask = crypto_cipher_alignmask(tfm);
struct cipher_alg *cia = crypto_cipher_alg(tfm);
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
enc ? cia->cia_encrypt : cia->cia_decrypt;
if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
unsigned int bs = crypto_cipher_blocksize(tfm);
u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(tmp, src, bs);
fn(crypto_cipher_tfm(tfm), tmp, tmp);
memcpy(dst, tmp, bs);
} else {
fn(crypto_cipher_tfm(tfm), dst, src);
}
}
void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
u8 *dst, const u8 *src)
{
cipher_crypt_one(tfm, dst, src, true);
}
EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, CRYPTO_INTERNAL);
void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
u8 *dst, const u8 *src)
{
cipher_crypt_one(tfm, dst, src, false);
}
EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, CRYPTO_INTERNAL);
struct crypto_cipher *crypto_clone_cipher(struct crypto_cipher *cipher)
{
struct crypto_tfm *tfm = crypto_cipher_tfm(cipher);
struct crypto_alg *alg = tfm->__crt_alg;
struct crypto_cipher *ncipher;
struct crypto_tfm *ntfm;
if (alg->cra_init)
return ERR_PTR(-ENOSYS);
if (unlikely(!crypto_mod_get(alg)))
return ERR_PTR(-ESTALE);
ntfm = __crypto_alloc_tfmgfp(alg, CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK, GFP_ATOMIC);
if (IS_ERR(ntfm)) {
crypto_mod_put(alg);
return ERR_CAST(ntfm);
}
ntfm->crt_flags = tfm->crt_flags;
ncipher = __crypto_cipher_cast(ntfm);
return ncipher;
}
EXPORT_SYMBOL_GPL(crypto_clone_cipher);