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82 lines
2.0 KiB
82 lines
2.0 KiB
/* |
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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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#define GMAC_MIC_LEN 16 |
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#define GMAC_NONCE_LEN 12 |
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#define AAD_LEN 20 |
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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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char aead_req_data[sizeof(struct aead_request) + |
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crypto_aead_reqsize(tfm)] |
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__aligned(__alignof__(struct aead_request)); |
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struct aead_request *aead_req = (void *)aead_req_data; |
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u8 zero[GMAC_MIC_LEN], iv[AES_BLOCK_SIZE]; |
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if (data_len < GMAC_MIC_LEN) |
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return -EINVAL; |
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memset(aead_req, 0, sizeof(aead_req_data)); |
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memset(zero, 0, GMAC_MIC_LEN); |
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sg_init_table(sg, 4); |
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sg_set_buf(&sg[0], aad, 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, AAD_LEN + data_len); |
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crypto_aead_encrypt(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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