cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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arc4.c (2136B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Cryptographic API
      4 *
      5 * ARC4 Cipher Algorithm
      6 *
      7 * Jon Oberheide <jon@oberheide.org>
      8 */
      9
     10#include <crypto/algapi.h>
     11#include <crypto/arc4.h>
     12#include <crypto/internal/skcipher.h>
     13#include <linux/init.h>
     14#include <linux/kernel.h>
     15#include <linux/module.h>
     16#include <linux/sched.h>
     17
     18static int crypto_arc4_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
     19			      unsigned int key_len)
     20{
     21	struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
     22
     23	return arc4_setkey(ctx, in_key, key_len);
     24}
     25
     26static int crypto_arc4_crypt(struct skcipher_request *req)
     27{
     28	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
     29	struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
     30	struct skcipher_walk walk;
     31	int err;
     32
     33	err = skcipher_walk_virt(&walk, req, false);
     34
     35	while (walk.nbytes > 0) {
     36		arc4_crypt(ctx, walk.dst.virt.addr, walk.src.virt.addr,
     37			   walk.nbytes);
     38		err = skcipher_walk_done(&walk, 0);
     39	}
     40
     41	return err;
     42}
     43
     44static int crypto_arc4_init(struct crypto_skcipher *tfm)
     45{
     46	pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n",
     47			    current->comm, (unsigned long)current->pid);
     48
     49	return 0;
     50}
     51
     52static struct skcipher_alg arc4_alg = {
     53	/*
     54	 * For legacy reasons, this is named "ecb(arc4)", not "arc4".
     55	 * Nevertheless it's actually a stream cipher, not a block cipher.
     56	 */
     57	.base.cra_name		=	"ecb(arc4)",
     58	.base.cra_driver_name	=	"ecb(arc4)-generic",
     59	.base.cra_priority	=	100,
     60	.base.cra_blocksize	=	ARC4_BLOCK_SIZE,
     61	.base.cra_ctxsize	=	sizeof(struct arc4_ctx),
     62	.base.cra_module	=	THIS_MODULE,
     63	.min_keysize		=	ARC4_MIN_KEY_SIZE,
     64	.max_keysize		=	ARC4_MAX_KEY_SIZE,
     65	.setkey			=	crypto_arc4_setkey,
     66	.encrypt		=	crypto_arc4_crypt,
     67	.decrypt		=	crypto_arc4_crypt,
     68	.init			=	crypto_arc4_init,
     69};
     70
     71static int __init arc4_init(void)
     72{
     73	return crypto_register_skcipher(&arc4_alg);
     74}
     75
     76static void __exit arc4_exit(void)
     77{
     78	crypto_unregister_skcipher(&arc4_alg);
     79}
     80
     81subsys_initcall(arc4_init);
     82module_exit(arc4_exit);
     83
     84MODULE_LICENSE("GPL");
     85MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
     86MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
     87MODULE_ALIAS_CRYPTO("ecb(arc4)");