f4a067f9ff
Some crypto implementations (such as the generic CCM wrapper in crypto/) use scatterlists to map fields of private data in their struct aead_req. This means these data structures cannot live in the vmalloc area, which means that they cannot live on the stack (with CONFIG_VMAP_STACK.) This currently occurs only with the generic software implementation, but the private data and usage is implementation specific, so move the whole data structures off the stack into heap by allocating every time we need to use them. In addition, take care not to put any of our own stack allocations into scatterlists. This involves reserving some extra room when allocating the aead_request structures, and referring to those allocations in the scatter- lists (while copying the data from the stack before the crypto operation) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
82 lines
2 KiB
C
82 lines
2 KiB
C
/*
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* AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256
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* Copyright 2015, Qualcomm Atheros, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/err.h>
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#include <crypto/aead.h>
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#include <crypto/aes.h>
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#include <net/mac80211.h>
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#include "key.h"
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#include "aes_gmac.h"
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int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
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const u8 *data, size_t data_len, u8 *mic)
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{
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struct scatterlist sg[4];
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u8 *zero, *__aad, iv[AES_BLOCK_SIZE];
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struct aead_request *aead_req;
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int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
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if (data_len < GMAC_MIC_LEN)
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return -EINVAL;
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aead_req = kzalloc(reqsize + GMAC_MIC_LEN + GMAC_AAD_LEN, GFP_ATOMIC);
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if (!aead_req)
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return -ENOMEM;
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zero = (u8 *)aead_req + reqsize;
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__aad = zero + GMAC_MIC_LEN;
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memcpy(__aad, aad, GMAC_AAD_LEN);
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sg_init_table(sg, 4);
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sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
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sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
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sg_set_buf(&sg[2], zero, GMAC_MIC_LEN);
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sg_set_buf(&sg[3], mic, GMAC_MIC_LEN);
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memcpy(iv, nonce, GMAC_NONCE_LEN);
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memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN);
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iv[AES_BLOCK_SIZE - 1] = 0x01;
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aead_request_set_tfm(aead_req, tfm);
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aead_request_set_crypt(aead_req, sg, sg, 0, iv);
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aead_request_set_ad(aead_req, GMAC_AAD_LEN + data_len);
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crypto_aead_encrypt(aead_req);
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kzfree(aead_req);
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return 0;
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}
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struct crypto_aead *ieee80211_aes_gmac_key_setup(const u8 key[],
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size_t key_len)
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{
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struct crypto_aead *tfm;
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int err;
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tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
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if (IS_ERR(tfm))
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return tfm;
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err = crypto_aead_setkey(tfm, key, key_len);
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if (!err)
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err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN);
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if (!err)
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return tfm;
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crypto_free_aead(tfm);
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return ERR_PTR(err);
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}
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void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm)
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{
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crypto_free_aead(tfm);
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}
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