1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Cryptographic API
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * ARC4 Cipher Algorithm
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Jon Oberheide <jon@oberheide.org>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <crypto/algapi.h>
11*4882a593Smuzhiyun #include <crypto/arc4.h>
12*4882a593Smuzhiyun #include <crypto/internal/skcipher.h>
13*4882a593Smuzhiyun #include <linux/init.h>
14*4882a593Smuzhiyun #include <linux/kernel.h>
15*4882a593Smuzhiyun #include <linux/module.h>
16*4882a593Smuzhiyun #include <linux/sched.h>
17*4882a593Smuzhiyun
crypto_arc4_setkey(struct crypto_skcipher * tfm,const u8 * in_key,unsigned int key_len)18*4882a593Smuzhiyun static int crypto_arc4_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
19*4882a593Smuzhiyun unsigned int key_len)
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun return arc4_setkey(ctx, in_key, key_len);
24*4882a593Smuzhiyun }
25*4882a593Smuzhiyun
crypto_arc4_crypt(struct skcipher_request * req)26*4882a593Smuzhiyun static int crypto_arc4_crypt(struct skcipher_request *req)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
29*4882a593Smuzhiyun struct arc4_ctx *ctx = crypto_skcipher_ctx(tfm);
30*4882a593Smuzhiyun struct skcipher_walk walk;
31*4882a593Smuzhiyun int err;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun err = skcipher_walk_virt(&walk, req, false);
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun while (walk.nbytes > 0) {
36*4882a593Smuzhiyun arc4_crypt(ctx, walk.dst.virt.addr, walk.src.virt.addr,
37*4882a593Smuzhiyun walk.nbytes);
38*4882a593Smuzhiyun err = skcipher_walk_done(&walk, 0);
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun return err;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun
crypto_arc4_init(struct crypto_skcipher * tfm)44*4882a593Smuzhiyun static int crypto_arc4_init(struct crypto_skcipher *tfm)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n",
47*4882a593Smuzhiyun current->comm, (unsigned long)current->pid);
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun return 0;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun static struct skcipher_alg arc4_alg = {
53*4882a593Smuzhiyun /*
54*4882a593Smuzhiyun * For legacy reasons, this is named "ecb(arc4)", not "arc4".
55*4882a593Smuzhiyun * Nevertheless it's actually a stream cipher, not a block cipher.
56*4882a593Smuzhiyun */
57*4882a593Smuzhiyun .base.cra_name = "ecb(arc4)",
58*4882a593Smuzhiyun .base.cra_driver_name = "ecb(arc4)-generic",
59*4882a593Smuzhiyun .base.cra_priority = 100,
60*4882a593Smuzhiyun .base.cra_blocksize = ARC4_BLOCK_SIZE,
61*4882a593Smuzhiyun .base.cra_ctxsize = sizeof(struct arc4_ctx),
62*4882a593Smuzhiyun .base.cra_module = THIS_MODULE,
63*4882a593Smuzhiyun .min_keysize = ARC4_MIN_KEY_SIZE,
64*4882a593Smuzhiyun .max_keysize = ARC4_MAX_KEY_SIZE,
65*4882a593Smuzhiyun .setkey = crypto_arc4_setkey,
66*4882a593Smuzhiyun .encrypt = crypto_arc4_crypt,
67*4882a593Smuzhiyun .decrypt = crypto_arc4_crypt,
68*4882a593Smuzhiyun .init = crypto_arc4_init,
69*4882a593Smuzhiyun };
70*4882a593Smuzhiyun
arc4_init(void)71*4882a593Smuzhiyun static int __init arc4_init(void)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun return crypto_register_skcipher(&arc4_alg);
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun
arc4_exit(void)76*4882a593Smuzhiyun static void __exit arc4_exit(void)
77*4882a593Smuzhiyun {
78*4882a593Smuzhiyun crypto_unregister_skcipher(&arc4_alg);
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun subsys_initcall(arc4_init);
82*4882a593Smuzhiyun module_exit(arc4_exit);
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun MODULE_LICENSE("GPL");
85*4882a593Smuzhiyun MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
86*4882a593Smuzhiyun MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
87*4882a593Smuzhiyun MODULE_ALIAS_CRYPTO("ecb(arc4)");
88