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{
  25        struct scatterlist assoc, pt, ct[2];
  26        struct {
  27                struct aead_request     req;
  28                u8                      priv[crypto_aead_reqsize(tfm)];
  29        } aead_req;
  30
  31        memset(&aead_req, 0, sizeof(aead_req));
  32
  33        sg_init_one(&pt, data, data_len);
  34        sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
  35        sg_init_table(ct, 2);
  36        sg_set_buf(&ct[0], data, data_len);
  37        sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);
  38
  39        aead_request_set_tfm(&aead_req.req, tfm);
  40        aead_request_set_assoc(&aead_req.req, &assoc, assoc.length);
  41        aead_request_set_crypt(&aead_req.req, &pt, ct, data_len, b_0);
  42
  43        crypto_aead_encrypt(&aead_req.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{
  49        struct scatterlist assoc, pt, ct[2];
  50        struct {
  51                struct aead_request     req;
  52                u8                      priv[crypto_aead_reqsize(tfm)];
  53        } aead_req;
  54
  55        memset(&aead_req, 0, sizeof(aead_req));
  56
  57        sg_init_one(&pt, data, data_len);
  58        sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
  59        sg_init_table(ct, 2);
  60        sg_set_buf(&ct[0], data, data_len);
  61        sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);
  62
  63        aead_request_set_tfm(&aead_req.req, tfm);
  64        aead_request_set_assoc(&aead_req.req, &assoc, assoc.length);
  65        aead_request_set_crypt(&aead_req.req, ct, &pt,
  66                               data_len + IEEE80211_CCMP_MIC_LEN, b_0);
  67
  68        return crypto_aead_decrypt(&aead_req.req);
  69}
  70
  71struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[])
  72{
  73        struct crypto_aead *tfm;
  74        int err;
  75
  76        tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
  77        if (IS_ERR(tfm))
  78                return tfm;
  79
  80        err = crypto_aead_setkey(tfm, key, WLAN_KEY_LEN_CCMP);
  81        if (!err)
  82                err = crypto_aead_setauthsize(tfm, IEEE80211_CCMP_MIC_LEN);
  83        if (!err)
  84                return tfm;
  85
  86        crypto_free_aead(tfm);
  87        return ERR_PTR(err);
  88}
  89
  90void ieee80211_aes_key_free(struct crypto_aead *tfm)
  91{
  92        crypto_free_aead(tfm);
  93}
  94