net/mac80211/aead_api.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2003-2004, Instant802 Networks, Inc.
   4  * Copyright 2005-2006, Devicescape Software, Inc.
   5  * Copyright 2014-2015, Qualcomm Atheros, Inc.
   6  *
   7  * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/types.h>
  12 #include <linux/err.h>
  13 #include <linux/scatterlist.h>
  14 #include <crypto/aead.h>
  15
  16 #include "aead_api.h"
  17
  18 int aead_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
  19                  u8 *data, size_t data_len, u8 *mic)
  20 {
  21         size_t mic_len = crypto_aead_authsize(tfm);
  22         struct scatterlist sg[3];
  23         struct aead_request *aead_req;
  24         int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
  25         u8 *__aad;
  26
  27         aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
  28         if (!aead_req)
  29                 return -ENOMEM;
  30
  31         __aad = (u8 *)aead_req + reqsize;
  32         memcpy(__aad, aad, aad_len);
  33
  34         sg_init_table(sg, 3);
  35         sg_set_buf(&sg[0], __aad, aad_len);
  36         sg_set_buf(&sg[1], data, data_len);
  37         sg_set_buf(&sg[2], mic, mic_len);
  38
  39         aead_request_set_tfm(aead_req, tfm);
  40         aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
  41         aead_request_set_ad(aead_req, sg[0].length);
  42
  43         crypto_aead_encrypt(aead_req);
  44         kzfree(aead_req);
  45
  46         return 0;
  47 }
  48
  49 int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
  50                  u8 *data, size_t data_len, u8 *mic)
  51 {
  52         size_t mic_len = crypto_aead_authsize(tfm);
  53         struct scatterlist sg[3];
  54         struct aead_request *aead_req;
  55         int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
  56         u8 *__aad;
  57         int err;
  58
  59         if (data_len == 0)
  60                 return -EINVAL;
  61
  62         aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
  63         if (!aead_req)
  64                 return -ENOMEM;
  65
  66         __aad = (u8 *)aead_req + reqsize;
  67         memcpy(__aad, aad, aad_len);
  68
  69         sg_init_table(sg, 3);
  70         sg_set_buf(&sg[0], __aad, aad_len);
  71         sg_set_buf(&sg[1], data, data_len);
  72         sg_set_buf(&sg[2], mic, mic_len);
  73
  74         aead_request_set_tfm(aead_req, tfm);
  75         aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
  76         aead_request_set_ad(aead_req, sg[0].length);
  77
  78         err = crypto_aead_decrypt(aead_req);
  79         kzfree(aead_req);
  80
  81         return err;
  82 }
  83
  84 struct crypto_aead *
  85 aead_key_setup_encrypt(const char *alg, const u8 key[],
  86                        size_t key_len, size_t mic_len)
  87 {
  88         struct crypto_aead *tfm;
  89         int err;
  90
  91         tfm = crypto_alloc_aead(alg, 0, CRYPTO_ALG_ASYNC);
  92         if (IS_ERR(tfm))
  93                 return tfm;
  94
  95         err = crypto_aead_setkey(tfm, key, key_len);
  96         if (err)
  97                 goto free_aead;
  98         err = crypto_aead_setauthsize(tfm, mic_len);
  99         if (err)
 100                 goto free_aead;
 101
 102         return tfm;
 103
 104 free_aead:
 105         crypto_free_aead(tfm);
 106         return ERR_PTR(err);
 107 }
 108
 109 void aead_key_free(struct crypto_aead *tfm)
 110 {
 111         crypto_free_aead(tfm);
 112 }