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         int ret;
  27
  28         aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
  29         if (!aead_req)
  30                 return -ENOMEM;
  31
  32         __aad = (u8 *)aead_req + reqsize;
  33         memcpy(__aad, aad, aad_len);
  34
  35         sg_init_table(sg, 3);
  36         sg_set_buf(&sg[0], __aad, aad_len);
  37         sg_set_buf(&sg[1], data, data_len);
  38         sg_set_buf(&sg[2], mic, mic_len);
  39
  40         aead_request_set_tfm(aead_req, tfm);
  41         aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
  42         aead_request_set_ad(aead_req, sg[0].length);
  43
  44         ret = crypto_aead_encrypt(aead_req);
  45         kfree_sensitive(aead_req);
  46
  47         return ret;
  48 }
  49
  50 int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
  51                  u8 *data, size_t data_len, u8 *mic)
  52 {
  53         size_t mic_len = crypto_aead_authsize(tfm);
  54         struct scatterlist sg[3];
  55         struct aead_request *aead_req;
  56         int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
  57         u8 *__aad;
  58         int err;
  59
  60         if (data_len == 0)
  61                 return -EINVAL;
  62
  63         aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
  64         if (!aead_req)
  65                 return -ENOMEM;
  66
  67         __aad = (u8 *)aead_req + reqsize;
  68         memcpy(__aad, aad, aad_len);
  69
  70         sg_init_table(sg, 3);
  71         sg_set_buf(&sg[0], __aad, aad_len);
  72         sg_set_buf(&sg[1], data, data_len);
  73         sg_set_buf(&sg[2], mic, mic_len);
  74
  75         aead_request_set_tfm(aead_req, tfm);
  76         aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
  77         aead_request_set_ad(aead_req, sg[0].length);
  78
  79         err = crypto_aead_decrypt(aead_req);
  80         kfree_sensitive(aead_req);
  81
  82         return err;
  83 }
  84
  85 struct crypto_aead *
  86 aead_key_setup_encrypt(const char *alg, const u8 key[],
  87                        size_t key_len, size_t mic_len)
  88 {
  89         struct crypto_aead *tfm;
  90         int err;
  91
  92         tfm = crypto_alloc_aead(alg, 0, CRYPTO_ALG_ASYNC);
  93         if (IS_ERR(tfm))
  94                 return tfm;
  95
  96         err = crypto_aead_setkey(tfm, key, key_len);
  97         if (err)
  98                 goto free_aead;
  99         err = crypto_aead_setauthsize(tfm, mic_len);
 100         if (err)
 101                 goto free_aead;
 102
 103         return tfm;
 104
 105 free_aead:
 106         crypto_free_aead(tfm);
 107         return ERR_PTR(err);
 108 }
 109
 110 void aead_key_free(struct crypto_aead *tfm)
 111 {
 112         crypto_free_aead(tfm);
 113 }