cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ctr.h (1456B)

      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/*
      3 * CTR: Counter mode
      4 *
      5 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
      6 */
      7
      8#ifndef _CRYPTO_CTR_H
      9#define _CRYPTO_CTR_H
     10
     11#include <crypto/algapi.h>
     12#include <crypto/internal/skcipher.h>
     13#include <linux/string.h>
     14#include <linux/types.h>
     15
     16#define CTR_RFC3686_NONCE_SIZE 4
     17#define CTR_RFC3686_IV_SIZE 8
     18#define CTR_RFC3686_BLOCK_SIZE 16
     19
     20static inline int crypto_ctr_encrypt_walk(struct skcipher_request *req,
     21					  void (*fn)(struct crypto_skcipher *,
     22						     const u8 *, u8 *))
     23{
     24	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
     25	int blocksize = crypto_skcipher_chunksize(tfm);
     26	u8 buf[MAX_CIPHER_BLOCKSIZE];
     27	struct skcipher_walk walk;
     28	int err;
     29
     30	/* avoid integer division due to variable blocksize parameter */
     31	if (WARN_ON_ONCE(!is_power_of_2(blocksize)))
     32		return -EINVAL;
     33
     34	err = skcipher_walk_virt(&walk, req, false);
     35
     36	while (walk.nbytes > 0) {
     37		u8 *dst = walk.dst.virt.addr;
     38		u8 *src = walk.src.virt.addr;
     39		int nbytes = walk.nbytes;
     40		int tail = 0;
     41
     42		if (nbytes < walk.total) {
     43			tail = walk.nbytes & (blocksize - 1);
     44			nbytes -= tail;
     45		}
     46
     47		do {
     48			int bsize = min(nbytes, blocksize);
     49
     50			fn(tfm, walk.iv, buf);
     51
     52			crypto_xor_cpy(dst, src, buf, bsize);
     53			crypto_inc(walk.iv, blocksize);
     54
     55			dst += bsize;
     56			src += bsize;
     57			nbytes -= bsize;
     58		} while (nbytes > 0);
     59
     60		err = skcipher_walk_done(&walk, tail);
     61	}
     62	return err;
     63}
     64
     65#endif  /* _CRYPTO_CTR_H */