Contributors: 3
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Ard Biesheuvel |
245 |
89.74% |
1 |
25.00% |
| Herbert Xu |
26 |
9.52% |
2 |
50.00% |
| Thomas Gleixner |
2 |
0.73% |
1 |
25.00% |
| Total |
273 |
|
4 |
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* CTR: Counter mode
*
* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
*/
#ifndef _CRYPTO_CTR_H
#define _CRYPTO_CTR_H
#include <crypto/algapi.h>
#include <crypto/internal/skcipher.h>
#include <linux/string.h>
#include <linux/types.h>
#define CTR_RFC3686_NONCE_SIZE 4
#define CTR_RFC3686_IV_SIZE 8
#define CTR_RFC3686_BLOCK_SIZE 16
static inline int crypto_ctr_encrypt_walk(struct skcipher_request *req,
void (*fn)(struct crypto_skcipher *,
const u8 *, u8 *))
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
int blocksize = crypto_skcipher_chunksize(tfm);
u8 buf[MAX_CIPHER_BLOCKSIZE];
struct skcipher_walk walk;
int err;
/* avoid integer division due to variable blocksize parameter */
if (WARN_ON_ONCE(!is_power_of_2(blocksize)))
return -EINVAL;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes > 0) {
const u8 *src = walk.src.virt.addr;
u8 *dst = walk.dst.virt.addr;
int nbytes = walk.nbytes;
int tail = 0;
if (nbytes < walk.total) {
tail = walk.nbytes & (blocksize - 1);
nbytes -= tail;
}
do {
int bsize = min(nbytes, blocksize);
fn(tfm, walk.iv, buf);
crypto_xor_cpy(dst, src, buf, bsize);
crypto_inc(walk.iv, blocksize);
dst += bsize;
src += bsize;
nbytes -= bsize;
} while (nbytes > 0);
err = skcipher_walk_done(&walk, tail);
}
return err;
}
#endif /* _CRYPTO_CTR_H */