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/crypto.h>
  15#include <linux/err.h>
  16#include <crypto/aes.h>
  17
  18#include <net/mac80211.h>
  19#include "key.h"
  20#include "aes_ccm.h"
  21
  22void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
  23                               u8 *data, size_t data_len, u8 *mic,
  24                               size_t mic_len)
  25{
  26        struct scatterlist assoc, pt, ct[2];
  27
  28        char aead_req_data[sizeof(struct aead_request) +
  29                           crypto_aead_reqsize(tfm)]
  30                __aligned(__alignof__(struct aead_request));
  31        struct aead_request *aead_req = (void *) aead_req_data;
  32
  33        memset(aead_req, 0, sizeof(aead_req_data));
  34
  35        sg_init_one(&pt, data, data_len);
  36        sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
  37        sg_init_table(ct, 2);
  38        sg_set_buf(&ct[0], data, data_len);
  39        sg_set_buf(&ct[1], mic, mic_len);
  40
  41        aead_request_set_tfm(aead_req, tfm);
  42        aead_request_set_assoc(aead_req, &assoc, assoc.length);
  43        aead_request_set_crypt(aead_req, &pt, ct, data_len, b_0);
  44
  45        crypto_aead_encrypt(aead_req);
  46}
  47
  48int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
  49                              u8 *data, size_t data_len, u8 *mic,
  50                              size_t mic_len)
  51{
  52        struct scatterlist assoc, pt, ct[2];
  53        char aead_req_data[sizeof(struct aead_request) +
  54                           crypto_aead_reqsize(tfm)]
  55                __aligned(__alignof__(struct aead_request));
  56        struct aead_request *aead_req = (void *) aead_req_data;
  57
  58        if (data_len == 0)
  59                return -EINVAL;
  60
  61        memset(aead_req, 0, sizeof(aead_req_data));
  62
  63        sg_init_one(&pt, data, data_len);
  64        sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
  65        sg_init_table(ct, 2);
  66        sg_set_buf(&ct[0], data, data_len);
  67        sg_set_buf(&ct[1], mic, mic_len);
  68
  69        aead_request_set_tfm(aead_req, tfm);
  70        aead_request_set_assoc(aead_req, &assoc, assoc.length);
  71        aead_request_set_crypt(aead_req, ct, &pt, data_len + mic_len, b_0);
  72
  73        return crypto_aead_decrypt(aead_req);
  74}
  75
  76struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
  77                                                    size_t key_len,
  78                                                    size_t mic_len)
  79{
  80        struct crypto_aead *tfm;
  81        int err;
  82
  83        tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
  84        if (IS_ERR(tfm))
  85                return tfm;
  86
  87        err = crypto_aead_setkey(tfm, key, key_len);
  88        if (err)
  89                goto free_aead;
  90        err = crypto_aead_setauthsize(tfm, mic_len);
  91        if (err)
  92                goto free_aead;
  93
  94        return tfm;
  95
  96free_aead:
  97        crypto_free_aead(tfm);
  98        return ERR_PTR(err);
  99}
 100
 101void ieee80211_aes_key_free(struct crypto_aead *tfm)
 102{
 103        crypto_free_aead(tfm);
 104}
 105