LXR linux/net/mac80211/aes

   1/*
   2 * Copyright 2003-2004, Instant802 Networks, Inc.
   3 * Copyright 2005-2006, Devicescape Software, Inc.
   4 *
   5 * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/types.h>
  14#include <linux/err.h>
  15#include <crypto/aead.h>
  16
  17#include <net/mac80211.h>
  18#include "key.h"
  19#include "aes_ccm.h"
  20
  21void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
  22                               u8 *data, size_t data_len, u8 *mic,
  23                               size_t mic_len)
  24{
  25        struct scatterlist sg[3];
  26
  27        char aead_req_data[sizeof(struct aead_request) +
  28                           crypto_aead_reqsize(tfm)]
  29                __aligned(__alignof__(struct aead_request));
  30        struct aead_request *aead_req = (void *) aead_req_data;
  31
  32        memset(aead_req, 0, sizeof(aead_req_data));
  33
  34        sg_init_table(sg, 3);
  35        sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
  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}
  45
  46int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
  47                              u8 *data, size_t data_len, u8 *mic,
  48                              size_t mic_len)
  49{
  50        struct scatterlist sg[3];
  51        char aead_req_data[sizeof(struct aead_request) +
  52                           crypto_aead_reqsize(tfm)]
  53                __aligned(__alignof__(struct aead_request));
  54        struct aead_request *aead_req = (void *) aead_req_data;
  55
  56        if (data_len == 0)
  57                return -EINVAL;
  58
  59        memset(aead_req, 0, sizeof(aead_req_data));
  60
  61        sg_init_table(sg, 3);
  62        sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
  63        sg_set_buf(&sg[1], data, data_len);
  64        sg_set_buf(&sg[2], mic, mic_len);
  65
  66        aead_request_set_tfm(aead_req, tfm);
  67        aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
  68        aead_request_set_ad(aead_req, sg[0].length);
  69
  70        return crypto_aead_decrypt(aead_req);
  71}
  72
  73struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
  74                                                    size_t key_len,
  75                                                    size_t mic_len)
  76{
  77        struct crypto_aead *tfm;
  78        int err;
  79
  80        tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
  81        if (IS_ERR(tfm))
  82                return tfm;
  83
  84        err = crypto_aead_setkey(tfm, key, key_len);
  85        if (err)
  86                goto free_aead;
  87        err = crypto_aead_setauthsize(tfm, mic_len);
  88        if (err)
  89                goto free_aead;
  90
  91        return tfm;
  92
  93free_aead:
  94        crypto_free_aead(tfm);
  95        return ERR_PTR(err);
  96}
  97
  98void ieee80211_aes_key_free(struct crypto_aead *tfm)
  99{
 100        crypto_free_aead(tfm);
 101}
 102