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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.
*
* Cipher operations.
*
* Copyright (c) 2002 James Morris <[email protected]>
* Copyright (c) 2005 Herbert Xu <[email protected]>
*/
#include <crypto/algapi.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_tfm *tfm, const u8 *key,
unsigned int keylen)
{
struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
unsigned long alignmask = crypto_tfm_alg_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(tfm, alignbuffer, keylen);
memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
if ((unsigned long)key & alignmask)
return setkey_unaligned(tfm, key, keylen);
return cia->cia_setkey(tfm, key, keylen);
}
static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
const u8 *),
struct crypto_tfm *tfm,
u8 *dst, const u8 *src)
{
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
unsigned int size = crypto_tfm_alg_blocksize(tfm);
u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(tmp, src, size);
fn(tfm, tmp, tmp);
memcpy(dst, tmp, size);
}
static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
u8 *dst, const u8 *src)
{
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
return;
}
cipher->cia_encrypt(tfm, dst, src);
}
static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
u8 *dst, const u8 *src)
{
unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
return;
}
cipher->cia_decrypt(tfm, dst, src);
}
int crypto_init_cipher_ops(struct crypto_tfm *tfm)
{
struct cipher_tfm *ops = &tfm->crt_cipher;
struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
ops->cit_setkey = setkey;
ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
cipher_encrypt_unaligned : cipher->cia_encrypt;
ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
cipher_decrypt_unaligned : cipher->cia_decrypt;
return 0;
}