Commit b688a944 authored by Chien Wong's avatar Chien Wong Committed by Johannes Berg
Browse files

wifi: mac80211: refactor CMAC packet handlers 



Merge CMAC-128 and CMAC-256 handlers since they are almost the same.
This removes duplication.

The comment 'MIC = AES-128-CMAC(IGTK, AAD ...' is out-dated since CMAC
is also used with BIGTK, as is the comment for CMAC-256. Simply remove
the comments.

Tested-on: mac80211_hwsim

Signed-off-by: default avatarChien Wong <m@xv97.com>
Link: https://patch.msgid.link/20251113140511.48658-6-m@xv97.com


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent a22fb192

net/mac80211/rx.c

+4 −2
Original line number Diff line number Diff line
@@ -2215,10 +2215,12 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) 
			rx, IEEE80211_CCMP_256_MIC_LEN);

		break;

	case WLAN_CIPHER_SUITE_AES_CMAC:

		result = ieee80211_crypto_aes_cmac_decrypt(rx);

		result = ieee80211_crypto_aes_cmac_decrypt(

			rx, IEEE80211_CMAC_128_MIC_LEN);

		break;

	case WLAN_CIPHER_SUITE_BIP_CMAC_256:

		result = ieee80211_crypto_aes_cmac_256_decrypt(rx);

		result = ieee80211_crypto_aes_cmac_decrypt(

			rx, IEEE80211_CMAC_256_MIC_LEN);

		break;

	case WLAN_CIPHER_SUITE_BIP_GMAC_128:

	case WLAN_CIPHER_SUITE_BIP_GMAC_256:

net/mac80211/tx.c

+4 −2
Original line number Diff line number Diff line
@@ -1062,9 +1062,11 @@ ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx) 
		return ieee80211_crypto_ccmp_encrypt(

			tx, IEEE80211_CCMP_256_MIC_LEN);

	case WLAN_CIPHER_SUITE_AES_CMAC:

		return ieee80211_crypto_aes_cmac_encrypt(tx);

		return ieee80211_crypto_aes_cmac_encrypt(

			tx, IEEE80211_CMAC_128_MIC_LEN);

	case WLAN_CIPHER_SUITE_BIP_CMAC_256:

		return ieee80211_crypto_aes_cmac_256_encrypt(tx);

		return ieee80211_crypto_aes_cmac_encrypt(

			tx, IEEE80211_CMAC_256_MIC_LEN);

	case WLAN_CIPHER_SUITE_BIP_GMAC_128:

	case WLAN_CIPHER_SUITE_BIP_GMAC_256:

		return ieee80211_crypto_aes_gmac_encrypt(tx);

net/mac80211/wpa.c

+25 −121
Original line number Diff line number Diff line
@@ -828,12 +828,14 @@ static inline void bip_ipn_swap(u8 *d, const u8 *s) 




ieee80211_tx_result

ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)

ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx,

				  unsigned int mic_len)

{

	struct sk_buff *skb;

	struct ieee80211_tx_info *info;

	struct ieee80211_key *key = tx->key;

	struct ieee80211_mmie *mmie;

	struct ieee80211_mmie_var *mmie;

	size_t mmie_len;

	u8 aad[20];

	u64 pn64;
@@ -848,62 +850,14 @@ ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) 
	    !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))

		return TX_CONTINUE;



	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))

		return TX_DROP;



	mmie = skb_put(skb, sizeof(*mmie));

	mmie->element_id = WLAN_EID_MMIE;

	mmie->length = sizeof(*mmie) - 2;

	mmie->key_id = cpu_to_le16(key->conf.keyidx);



	/* PN = PN + 1 */

	pn64 = atomic64_inc_return(&key->conf.tx_pn);



	bip_ipn_set64(mmie->sequence_number, pn64);



	if (info->control.hw_key)

		return TX_CONTINUE;



	bip_aad(skb, aad);

	mmie_len = sizeof(*mmie) + mic_len;



	/*

	 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)

	 */

	if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,

			       skb->data + 24, skb->len - 24, mmie->mic,

			       IEEE80211_CMAC_128_MIC_LEN))

	if (WARN_ON(skb_tailroom(skb) < mmie_len))

		return TX_DROP;



	return TX_CONTINUE;

}



ieee80211_tx_result

ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)

{

	struct sk_buff *skb;

	struct ieee80211_tx_info *info;

	struct ieee80211_key *key = tx->key;

	struct ieee80211_mmie_16 *mmie;

	u8 aad[20];

	u64 pn64;



	if (WARN_ON(skb_queue_len(&tx->skbs) != 1))

		return TX_DROP;



	skb = skb_peek(&tx->skbs);



	info = IEEE80211_SKB_CB(skb);



	if (info->control.hw_key &&

	    !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))

		return TX_CONTINUE;



	if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))

		return TX_DROP;



	mmie = skb_put(skb, sizeof(*mmie));

	mmie = skb_put(skb, mmie_len);

	mmie->element_id = WLAN_EID_MMIE;

	mmie->length = sizeof(*mmie) - 2;

	mmie->length = mmie_len - 2;

	mmie->key_id = cpu_to_le16(key->conf.keyidx);



	/* PN = PN + 1 */
@@ -916,90 +870,40 @@ ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx) 


	bip_aad(skb, aad);



	/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)

	 */

	if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,

			       skb->data + 24, skb->len - 24, mmie->mic,

			       IEEE80211_CMAC_256_MIC_LEN))

			       skb->data + 24, skb->len - 24,

			       mmie->mic, mic_len))

		return TX_DROP;



	return TX_CONTINUE;

}



ieee80211_rx_result

ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)

ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx,

				  unsigned int mic_len)

{

	struct sk_buff *skb = rx->skb;

	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);

	struct ieee80211_key *key = rx->key;

	struct ieee80211_mmie *mmie;

	u8 aad[20], mic[8], ipn[6];

	struct ieee80211_mmie_var *mmie;

	size_t mmie_len;

	u8 aad[20], mic[IEEE80211_CMAC_256_MIC_LEN], ipn[6];

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



	if (!ieee80211_is_mgmt(hdr->frame_control))

		return RX_CONTINUE;



	/* management frames are already linear */



	if (skb->len < 24 + sizeof(*mmie))

		return RX_DROP_U_SHORT_CMAC;



	mmie = (struct ieee80211_mmie *)

		(skb->data + skb->len - sizeof(*mmie));

	if (mmie->element_id != WLAN_EID_MMIE ||

	    mmie->length != sizeof(*mmie) - 2)

		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */



	bip_ipn_swap(ipn, mmie->sequence_number);



	if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {

		key->u.aes_cmac.replays++;

		return RX_DROP_U_REPLAY;

	}



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

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

		bip_aad(skb, aad);

		if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,

				       skb->data + 24, skb->len - 24, mic,

				       IEEE80211_CMAC_128_MIC_LEN))

			return RX_DROP_U_DECRYPT_FAIL;

		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {

			key->u.aes_cmac.icverrors++;

			return RX_DROP_U_MIC_FAIL;

		}

	}



	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);



	/* Remove MMIE */

	skb_trim(skb, skb->len - sizeof(*mmie));



	return RX_CONTINUE;

}



ieee80211_rx_result

ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)

{

	struct sk_buff *skb = rx->skb;

	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);

	struct ieee80211_key *key = rx->key;

	struct ieee80211_mmie_16 *mmie;

	u8 aad[20], mic[16], ipn[6];

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



	if (!ieee80211_is_mgmt(hdr->frame_control))

		return RX_CONTINUE;

	mmie_len = sizeof(*mmie) + mic_len;



	/* management frames are already linear */



	if (skb->len < 24 + sizeof(*mmie))

		return RX_DROP_U_SHORT_CMAC256;

	if (skb->len < 24 + mmie_len)

		return mic_len == IEEE80211_CMAC_128_MIC_LEN ?

			RX_DROP_U_SHORT_CMAC : RX_DROP_U_SHORT_CMAC256;



	mmie = (struct ieee80211_mmie_16 *)

		(skb->data + skb->len - sizeof(*mmie));

	mmie = (struct ieee80211_mmie_var *)(skb->data + skb->len - mmie_len);

	if (mmie->element_id != WLAN_EID_MMIE ||

	    mmie->length != sizeof(*mmie) - 2)

	    mmie->length != mmie_len - 2)

		return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */



	bip_ipn_swap(ipn, mmie->sequence_number);
@@ -1013,10 +917,10 @@ ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx) 
		/* hardware didn't decrypt/verify MIC */

		bip_aad(skb, aad);

		if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,

				       skb->data + 24, skb->len - 24, mic,

				       IEEE80211_CMAC_256_MIC_LEN))

				       skb->data + 24, skb->len - 24,

				       mic, mic_len))

			return RX_DROP_U_DECRYPT_FAIL;

		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {

		if (crypto_memneq(mic, mmie->mic, mic_len)) {

			key->u.aes_cmac.icverrors++;

			return RX_DROP_U_MIC_FAIL;

		}
@@ -1025,7 +929,7 @@ ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx) 
	memcpy(key->u.aes_cmac.rx_pn, ipn, 6);



	/* Remove MMIE */

	skb_trim(skb, skb->len - sizeof(*mmie));

	skb_trim(skb, skb->len - mmie_len);



	return RX_CONTINUE;

}

net/mac80211/wpa.h

+4 −6
Original line number Diff line number Diff line
@@ -29,13 +29,11 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx, 
			      unsigned int mic_len);



ieee80211_tx_result

ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx);

ieee80211_tx_result

ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx);

ieee80211_rx_result

ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx);

ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx,

				  unsigned int mic_len);

ieee80211_rx_result

ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx);

ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx,

				  unsigned int mic_len);

ieee80211_tx_result

ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx);

ieee80211_rx_result