crypto/arc4.c

   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
  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
  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
  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
  66 static int __init arc4_init(void)
  67 {
  68         return crypto_register_lskcipher(&arc4_alg);
  69 }
  70
  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)");