LXR linux/net/mac80211/aes

   1/*
   2 * Copyright 2014-2015, Qualcomm Atheros, Inc.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/types.h>
  11#include <linux/err.h>
  12#include <crypto/aead.h>
  13
  14#include <net/mac80211.h>
  15#include "key.h"
  16#include "aes_gcm.h"
  17
  18void ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
  19                               u8 *data, size_t data_len, u8 *mic)
  20{
  21        struct scatterlist sg[3];
  22
  23        char aead_req_data[sizeof(struct aead_request) +
  24                           crypto_aead_reqsize(tfm)]
  25                __aligned(__alignof__(struct aead_request));
  26        struct aead_request *aead_req = (void *)aead_req_data;
  27
  28        memset(aead_req, 0, sizeof(aead_req_data));
  29
  30        sg_init_table(sg, 3);
  31        sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
  32        sg_set_buf(&sg[1], data, data_len);
  33        sg_set_buf(&sg[2], mic, IEEE80211_GCMP_MIC_LEN);
  34
  35        aead_request_set_tfm(aead_req, tfm);
  36        aead_request_set_crypt(aead_req, sg, sg, data_len, j_0);
  37        aead_request_set_ad(aead_req, sg[0].length);
  38
  39        crypto_aead_encrypt(aead_req);
  40}
  41
  42int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
  43                              u8 *data, size_t data_len, u8 *mic)
  44{
  45        struct scatterlist sg[3];
  46        char aead_req_data[sizeof(struct aead_request) +
  47                           crypto_aead_reqsize(tfm)]
  48                __aligned(__alignof__(struct aead_request));
  49        struct aead_request *aead_req = (void *)aead_req_data;
  50
  51        if (data_len == 0)
  52                return -EINVAL;
  53
  54        memset(aead_req, 0, sizeof(aead_req_data));
  55
  56        sg_init_table(sg, 3);
  57        sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
  58        sg_set_buf(&sg[1], data, data_len);
  59        sg_set_buf(&sg[2], mic, IEEE80211_GCMP_MIC_LEN);
  60
  61        aead_request_set_tfm(aead_req, tfm);
  62        aead_request_set_crypt(aead_req, sg, sg,
  63                               data_len + IEEE80211_GCMP_MIC_LEN, j_0);
  64        aead_request_set_ad(aead_req, sg[0].length);
  65
  66        return crypto_aead_decrypt(aead_req);
  67}
  68
  69struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(const u8 key[],
  70                                                        size_t key_len)
  71{
  72        struct crypto_aead *tfm;
  73        int err;
  74
  75        tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
  76        if (IS_ERR(tfm))
  77                return tfm;
  78
  79        err = crypto_aead_setkey(tfm, key, key_len);
  80        if (err)
  81                goto free_aead;
  82        err = crypto_aead_setauthsize(tfm, IEEE80211_GCMP_MIC_LEN);
  83        if (err)
  84                goto free_aead;
  85
  86        return tfm;
  87
  88free_aead:
  89        crypto_free_aead(tfm);
  90        return ERR_PTR(err);
  91}
  92
  93void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm)
  94{
  95        crypto_free_aead(tfm);
  96}
  97