/*
 * AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256
 * Copyright 2015, Qualcomm Atheros, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/err.h>
#include <crypto/aead.h>
#include <crypto/aes.h>

#include <net/mac80211.h>
#include "key.h"
#include "aes_gmac.h"

int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
		       const u8 *data, size_t data_len, u8 *mic)
{
	struct scatterlist sg[4];
	u8 *zero, *__aad, iv[AES_BLOCK_SIZE];
	struct aead_request *aead_req;
	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);

	if (data_len < GMAC_MIC_LEN)
		return -EINVAL;

	aead_req = kzalloc(reqsize + GMAC_MIC_LEN + GMAC_AAD_LEN, GFP_ATOMIC);
	if (!aead_req)
		return -ENOMEM;

	zero = (u8 *)aead_req + reqsize;
	__aad = zero + GMAC_MIC_LEN;
	memcpy(__aad, aad, GMAC_AAD_LEN);

	sg_init_table(sg, 4);
	sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
	sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
	sg_set_buf(&sg[2], zero, GMAC_MIC_LEN);
	sg_set_buf(&sg[3], mic, GMAC_MIC_LEN);

	memcpy(iv, nonce, GMAC_NONCE_LEN);
	memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN);
	iv[AES_BLOCK_SIZE - 1] = 0x01;

	aead_request_set_tfm(aead_req, tfm);
	aead_request_set_crypt(aead_req, sg, sg, 0, iv);
	aead_request_set_ad(aead_req, GMAC_AAD_LEN + data_len);

	crypto_aead_encrypt(aead_req);
	kzfree(aead_req);

	return 0;
}

struct crypto_aead *ieee80211_aes_gmac_key_setup(const u8 key[],
						 size_t key_len)
{
	struct crypto_aead *tfm;
	int err;

	tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm))
		return tfm;

	err = crypto_aead_setkey(tfm, key, key_len);
	if (!err)
		err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN);
	if (!err)
		return tfm;

	crypto_free_aead(tfm);
	return ERR_PTR(err);
}

void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm)
{
	crypto_free_aead(tfm);
}
f'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/net/mac80211/iface.c'>
<input type='hidden' name='id' value='aca9fa0c8d225b1446dbed798b1d2f20e37e52cf'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/?id=aca9fa0c8d225b1446dbed798b1d2f20e37e52cf'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/net?id=aca9fa0c8d225b1446dbed798b1d2f20e37e52cf'>net</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/mac80211?id=aca9fa0c8d225b1446dbed798b1d2f20e37e52cf'>mac80211</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/mac80211/iface.c?id=aca9fa0c8d225b1446dbed798b1d2f20e37e52cf'>iface.c</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/net/mac80211/iface.c?id=aca9fa0c8d225b1446dbed798b1d2f20e37e52cf&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>