crypto/sm4_generic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * SM4 Cipher Algorithm.
   5  *
   6  * Copyright (C) 2018 ARM Limited or its affiliates.
   7  * All rights reserved.
   8  */
   9
  10 #include <crypto/algapi.h>
  11 #include <crypto/sm4.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/types.h>
  15 #include <linux/errno.h>
  16 #include <asm/byteorder.h>
  17 #include <linux/unaligned.h>
  18
  19 /**
  20  * sm4_setkey - Set the SM4 key.
  21  * @tfm:        The %crypto_tfm that is used in the context.
  22  * @in_key:     The input key.
  23  * @key_len:    The size of the key.
  24  *
  25  * This function uses sm4_expandkey() to expand the key.
  26  * &sm4_ctx _must_ be the private data embedded in @tfm which is
  27  * retrieved with crypto_tfm_ctx().
  28  *
  29  * Return: 0 on success; -EINVAL on failure (only happens for bad key lengths)
  30  */
  31 static int sm4_setkey(struct crypto_tfm *tfm, const u8 *in_key,
  32                        unsigned int key_len)
  33 {
  34         struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  35
  36         return sm4_expandkey(ctx, in_key, key_len);
  37 }
  38
  39 /* encrypt a block of text */
  40
  41 static void sm4_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  42 {
  43         const struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  44
  45         sm4_crypt_block(ctx->rkey_enc, out, in);
  46 }
  47
  48 /* decrypt a block of text */
  49
  50 static void sm4_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  51 {
  52         const struct sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  53
  54         sm4_crypt_block(ctx->rkey_dec, out, in);
  55 }
  56
  57 static struct crypto_alg sm4_alg = {
  58         .cra_name               =       "sm4",
  59         .cra_driver_name        =       "sm4-generic",
  60         .cra_priority           =       100,
  61         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
  62         .cra_blocksize          =       SM4_BLOCK_SIZE,
  63         .cra_ctxsize            =       sizeof(struct sm4_ctx),
  64         .cra_module             =       THIS_MODULE,
  65         .cra_u                  =       {
  66                 .cipher = {
  67                         .cia_min_keysize        =       SM4_KEY_SIZE,
  68                         .cia_max_keysize        =       SM4_KEY_SIZE,
  69                         .cia_setkey             =       sm4_setkey,
  70                         .cia_encrypt            =       sm4_encrypt,
  71                         .cia_decrypt            =       sm4_decrypt
  72                 }
  73         }
  74 };
  75
  76 static int __init sm4_init(void)
  77 {
  78         return crypto_register_alg(&sm4_alg);
  79 }
  80
  81 static void __exit sm4_fini(void)
  82 {
  83         crypto_unregister_alg(&sm4_alg);
  84 }
  85
  86 subsys_initcall(sm4_init);
  87 module_exit(sm4_fini);
  88
  89 MODULE_DESCRIPTION("SM4 Cipher Algorithm");
  90 MODULE_LICENSE("GPL v2");
  91 MODULE_ALIAS_CRYPTO("sm4");
  92 MODULE_ALIAS_CRYPTO("sm4-generic");