xref: /linux/crypto/arc4.c (revision 06d07429858317ded2db7986113a9e0129cd599b)
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/arc4.h>
11 #include <crypto/internal/skcipher.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 
17 #define ARC4_ALIGN __alignof__(struct arc4_ctx)
18 
crypto_arc4_setkey(struct crypto_lskcipher * tfm,const u8 * in_key,unsigned int key_len)19 static int crypto_arc4_setkey(struct crypto_lskcipher *tfm, const u8 *in_key,
20 			      unsigned int key_len)
21 {
22 	struct arc4_ctx *ctx = crypto_lskcipher_ctx(tfm);
23 
24 	return arc4_setkey(ctx, in_key, key_len);
25 }
26 
crypto_arc4_crypt(struct crypto_lskcipher * tfm,const u8 * src,u8 * dst,unsigned nbytes,u8 * siv,u32 flags)27 static int crypto_arc4_crypt(struct crypto_lskcipher *tfm, const u8 *src,
28 			     u8 *dst, unsigned nbytes, u8 *siv, u32 flags)
29 {
30 	struct arc4_ctx *ctx = crypto_lskcipher_ctx(tfm);
31 
32 	if (!(flags & CRYPTO_LSKCIPHER_FLAG_CONT))
33 		memcpy(siv, ctx, sizeof(*ctx));
34 
35 	ctx = (struct arc4_ctx *)siv;
36 
37 	arc4_crypt(ctx, dst, src, nbytes);
38 	return 0;
39 }
40 
crypto_arc4_init(struct crypto_lskcipher * tfm)41 static int crypto_arc4_init(struct crypto_lskcipher *tfm)
42 {
43 	pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n",
44 			    current->comm, (unsigned long)current->pid);
45 
46 	return 0;
47 }
48 
49 static struct lskcipher_alg arc4_alg = {
50 	.co.base.cra_name		=	"arc4",
51 	.co.base.cra_driver_name	=	"arc4-generic",
52 	.co.base.cra_priority		=	100,
53 	.co.base.cra_blocksize		=	ARC4_BLOCK_SIZE,
54 	.co.base.cra_ctxsize		=	sizeof(struct arc4_ctx),
55 	.co.base.cra_alignmask		=	ARC4_ALIGN - 1,
56 	.co.base.cra_module		=	THIS_MODULE,
57 	.co.min_keysize			=	ARC4_MIN_KEY_SIZE,
58 	.co.max_keysize			=	ARC4_MAX_KEY_SIZE,
59 	.co.statesize			=	sizeof(struct arc4_ctx),
60 	.setkey				=	crypto_arc4_setkey,
61 	.encrypt			=	crypto_arc4_crypt,
62 	.decrypt			=	crypto_arc4_crypt,
63 	.init				=	crypto_arc4_init,
64 };
65 
arc4_init(void)66 static int __init arc4_init(void)
67 {
68 	return crypto_register_lskcipher(&arc4_alg);
69 }
70 
arc4_exit(void)71 static void __exit arc4_exit(void)
72 {
73 	crypto_unregister_lskcipher(&arc4_alg);
74 }
75 
76 subsys_initcall(arc4_init);
77 module_exit(arc4_exit);
78 
79 MODULE_LICENSE("GPL");
80 MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
81 MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
82 MODULE_ALIAS_CRYPTO("ecb(arc4)");
83