Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7ec7c4a9 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Johannes Berg
Browse files

mac80211: port CCMP to cryptoapi's CCM driver 



Use the generic CCM aead chaining mode driver rather than a local
implementation that sits right on top of the core AES cipher.

This allows the use of accelerated implementations of either
CCM as a whole or the CTR mode which it encapsulates.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent fa1fb9cb

net/mac80211/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ config MAC80211 
	select CRYPTO

	select CRYPTO_ARC4

	select CRYPTO_AES

	select CRYPTO_CCM

	select CRC32

	select AVERAGE

	---help---

net/mac80211/aes_ccm.c

+56 −113
Original line number Diff line number Diff line
@@ -2,6 +2,8 @@ 
 * Copyright 2003-2004, Instant802 Networks, Inc.

 * Copyright 2005-2006, Devicescape Software, Inc.

 *

 * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>

 *

 * 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.
@@ -17,134 +19,75 @@ 
#include "key.h"

#include "aes_ccm.h"



static void aes_ccm_prepare(struct crypto_cipher *tfm, u8 *scratch, u8 *a)

void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,

			       u8 *data, size_t data_len, u8 *mic)

{

	int i;

	u8 *b_0, *aad, *b, *s_0;



	b_0 = scratch + 3 * AES_BLOCK_SIZE;

	aad = scratch + 4 * AES_BLOCK_SIZE;

	b = scratch;

	s_0 = scratch + AES_BLOCK_SIZE;



	crypto_cipher_encrypt_one(tfm, b, b_0);



	/* Extra Authenticate-only data (always two AES blocks) */

	for (i = 0; i < AES_BLOCK_SIZE; i++)

		aad[i] ^= b[i];

	crypto_cipher_encrypt_one(tfm, b, aad);



	aad += AES_BLOCK_SIZE;

	struct scatterlist assoc, pt, ct[2];

	struct {

		struct aead_request	req;

		u8			priv[crypto_aead_reqsize(tfm)];

	} aead_req;



	for (i = 0; i < AES_BLOCK_SIZE; i++)

		aad[i] ^= b[i];

	crypto_cipher_encrypt_one(tfm, a, aad);

	memset(&aead_req, 0, sizeof(aead_req));



	/* Mask out bits from auth-only-b_0 */

	b_0[0] &= 0x07;

	sg_init_one(&pt, data, data_len);

	sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));

	sg_init_table(ct, 2);

	sg_set_buf(&ct[0], data, data_len);

	sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);



	/* S_0 is used to encrypt T (= MIC) */

	b_0[14] = 0;

	b_0[15] = 0;

	crypto_cipher_encrypt_one(tfm, s_0, b_0);

}





void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch,

			       u8 *data, size_t data_len,

			       u8 *cdata, u8 *mic)

{

	int i, j, last_len, num_blocks;

	u8 *pos, *cpos, *b, *s_0, *e, *b_0;



	b = scratch;

	s_0 = scratch + AES_BLOCK_SIZE;

	e = scratch + 2 * AES_BLOCK_SIZE;

	b_0 = scratch + 3 * AES_BLOCK_SIZE;



	num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_SIZE);

	last_len = data_len % AES_BLOCK_SIZE;

	aes_ccm_prepare(tfm, scratch, b);



	/* Process payload blocks */

	pos = data;

	cpos = cdata;

	for (j = 1; j <= num_blocks; j++) {

		int blen = (j == num_blocks && last_len) ?

			last_len : AES_BLOCK_SIZE;



		/* Authentication followed by encryption */

		for (i = 0; i < blen; i++)

			b[i] ^= pos[i];

		crypto_cipher_encrypt_one(tfm, b, b);



		b_0[14] = (j >> 8) & 0xff;

		b_0[15] = j & 0xff;

		crypto_cipher_encrypt_one(tfm, e, b_0);

		for (i = 0; i < blen; i++)

			*cpos++ = *pos++ ^ e[i];

	}

	aead_request_set_tfm(&aead_req.req, tfm);

	aead_request_set_assoc(&aead_req.req, &assoc, assoc.length);

	aead_request_set_crypt(&aead_req.req, &pt, ct, data_len, b_0);



	for (i = 0; i < IEEE80211_CCMP_MIC_LEN; i++)

		mic[i] = b[i] ^ s_0[i];

	crypto_aead_encrypt(&aead_req.req);

}





int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch,

			      u8 *cdata, size_t data_len, u8 *mic, u8 *data)

int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,

			      u8 *data, size_t data_len, u8 *mic)

{

	int i, j, last_len, num_blocks;

	u8 *pos, *cpos, *b, *s_0, *a, *b_0;



	b = scratch;

	s_0 = scratch + AES_BLOCK_SIZE;

	a = scratch + 2 * AES_BLOCK_SIZE;

	b_0 = scratch + 3 * AES_BLOCK_SIZE;



	num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_SIZE);

	last_len = data_len % AES_BLOCK_SIZE;

	aes_ccm_prepare(tfm, scratch, a);



	/* Process payload blocks */

	cpos = cdata;

	pos = data;

	for (j = 1; j <= num_blocks; j++) {

		int blen = (j == num_blocks && last_len) ?

			last_len : AES_BLOCK_SIZE;



		/* Decryption followed by authentication */

		b_0[14] = (j >> 8) & 0xff;

		b_0[15] = j & 0xff;

		crypto_cipher_encrypt_one(tfm, b, b_0);

		for (i = 0; i < blen; i++) {

			*pos = *cpos++ ^ b[i];

			a[i] ^= *pos++;

		}

		crypto_cipher_encrypt_one(tfm, a, a);

	}



	for (i = 0; i < IEEE80211_CCMP_MIC_LEN; i++) {

		if ((mic[i] ^ s_0[i]) != a[i])

			return -1;

	}



	return 0;

	struct scatterlist assoc, pt, ct[2];

	struct {

		struct aead_request	req;

		u8			priv[crypto_aead_reqsize(tfm)];

	} aead_req;



	memset(&aead_req, 0, sizeof(aead_req));



	sg_init_one(&pt, data, data_len);

	sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));

	sg_init_table(ct, 2);

	sg_set_buf(&ct[0], data, data_len);

	sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);



	aead_request_set_tfm(&aead_req.req, tfm);

	aead_request_set_assoc(&aead_req.req, &assoc, assoc.length);

	aead_request_set_crypt(&aead_req.req, ct, &pt,

			       data_len + IEEE80211_CCMP_MIC_LEN, b_0);



	return crypto_aead_decrypt(&aead_req.req);

}





struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[])

struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[])

{

	struct crypto_cipher *tfm;

	struct crypto_aead *tfm;

	int err;



	tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);

	if (!IS_ERR(tfm))

		crypto_cipher_setkey(tfm, key, WLAN_KEY_LEN_CCMP);

	tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm))

		return tfm;



	err = crypto_aead_setkey(tfm, key, WLAN_KEY_LEN_CCMP);

	if (!err)

		err = crypto_aead_setauthsize(tfm, IEEE80211_CCMP_MIC_LEN);

	if (!err)

		return tfm;

}



	crypto_free_aead(tfm);

	return ERR_PTR(err);

}



void ieee80211_aes_key_free(struct crypto_cipher *tfm)

void ieee80211_aes_key_free(struct crypto_aead *tfm)

{

	crypto_free_cipher(tfm);

	crypto_free_aead(tfm);

}

net/mac80211/aes_ccm.h

+6 −8
Original line number Diff line number Diff line
@@ -12,13 +12,11 @@ 


#include <linux/crypto.h>



struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[]);

void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch,

			       u8 *data, size_t data_len,

			       u8 *cdata, u8 *mic);

int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch,

			      u8 *cdata, size_t data_len,

			      u8 *mic, u8 *data);

void ieee80211_aes_key_free(struct crypto_cipher *tfm);

struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[]);

void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,

			       u8 *data, size_t data_len, u8 *mic);

int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,

			      u8 *data, size_t data_len, u8 *mic);

void ieee80211_aes_key_free(struct crypto_aead *tfm);



#endif /* AES_CCM_H */

net/mac80211/key.h

+1 −1
Original line number Diff line number Diff line
@@ -83,7 +83,7 @@ struct ieee80211_key { 
			 * Management frames.

			 */

			u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_CCMP_PN_LEN];

			struct crypto_cipher *tfm;

			struct crypto_aead *tfm;

			u32 replays; /* dot11RSNAStatsCCMPReplays */

		} ccmp;

		struct {

net/mac80211/wpa.c

+20 −24
Original line number Diff line number Diff line
@@ -301,22 +301,16 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) 
}





static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,

static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,

				int encrypted)

{

	__le16 mask_fc;

	int a4_included, mgmt;

	u8 qos_tid;

	u8 *b_0, *aad;

	u16 data_len, len_a;

	u16 len_a;

	unsigned int hdrlen;

	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;



	memset(scratch, 0, 6 * AES_BLOCK_SIZE);



	b_0 = scratch + 3 * AES_BLOCK_SIZE;

	aad = scratch + 4 * AES_BLOCK_SIZE;



	/*

	 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)

	 * Retry, PwrMgt, MoreData; set Protected
@@ -338,20 +332,21 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, 
	else

		qos_tid = 0;



	data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN;

	if (encrypted)

		data_len -= IEEE80211_CCMP_MIC_LEN;

	/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC

	 * mode authentication are not allowed to collide, yet both are derived

	 * from this vector b_0. We only set L := 1 here to indicate that the

	 * data size can be represented in (L+1) bytes. The CCM layer will take

	 * care of storing the data length in the top (L+1) bytes and setting

	 * and clearing the other bits as is required to derive the two IVs.

	 */

	b_0[0] = 0x1;



	/* First block, b_0 */

	b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */

	/* Nonce: Nonce Flags | A2 | PN

	 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)

	 */

	b_0[1] = qos_tid | (mgmt << 4);

	memcpy(&b_0[2], hdr->addr2, ETH_ALEN);

	memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);

	/* l(m) */

	put_unaligned_be16(data_len, &b_0[14]);



	/* AAD (extra authenticate-only data) / masked 802.11 header

	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
@@ -407,7 +402,8 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 
	u8 *pos;

	u8 pn[6];

	u64 pn64;

	u8 scratch[6 * AES_BLOCK_SIZE];

	u8 aad[2 * AES_BLOCK_SIZE];

	u8 b_0[AES_BLOCK_SIZE];



	if (info->control.hw_key &&

	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
@@ -460,9 +456,9 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) 
		return 0;



	pos += IEEE80211_CCMP_HDR_LEN;

	ccmp_special_blocks(skb, pn, scratch, 0);

	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len,

				  pos, skb_put(skb, IEEE80211_CCMP_MIC_LEN));

	ccmp_special_blocks(skb, pn, b_0, aad, 0);

	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,

				  skb_put(skb, IEEE80211_CCMP_MIC_LEN));



	return 0;

}
@@ -525,16 +521,16 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) 
	}



	if (!(status->flag & RX_FLAG_DECRYPTED)) {

		u8 scratch[6 * AES_BLOCK_SIZE];

		u8 aad[2 * AES_BLOCK_SIZE];

		u8 b_0[AES_BLOCK_SIZE];

		/* hardware didn't decrypt/verify MIC */

		ccmp_special_blocks(skb, pn, scratch, 1);

		ccmp_special_blocks(skb, pn, b_0, aad, 1);



		if (ieee80211_aes_ccm_decrypt(

			    key->u.ccmp.tfm, scratch,

			    key->u.ccmp.tfm, b_0, aad,

			    skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,

			    data_len,

			    skb->data + skb->len - IEEE80211_CCMP_MIC_LEN,

			    skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN))

			    skb->data + skb->len - IEEE80211_CCMP_MIC_LEN))

			return RX_DROP_UNUSABLE;

	}