From 2d5d4b0a6da1271a7dfa9a7052870361e72ba424 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <jouni@codeaurora.org>
Date: Sat, 22 Feb 2020 15:25:45 +0200
Subject: [PATCH] mac80211: Update BIP to support Beacon frames
Git-commit: 2d5d4b0a6da1271a7dfa9a7052870361e72ba424
Patch-mainline: v5.7-rc1
References: jsc#SLE-13430

When BIP is used to protect Beacon frames, the Timestamp field is masked
to zero. Otherwise, the BIP processing is identical to the way it was
already used with group-addressed Robust Management frames.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200222132548.20835-4-jouni@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/mac80211/aes_cmac.c | 21 +++++++++++++++++++--
 net/mac80211/aes_gmac.c | 24 ++++++++++++++++++------
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index 57748cab0e28..b31f1021ad9c 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -26,12 +26,20 @@ void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
 {
 	SHASH_DESC_ON_STACK(desc, tfm);
 	u8 out[AES_BLOCK_SIZE];
+	const __le16 *fc;
 
 	desc->tfm = tfm;
 
 	crypto_shash_init(desc);
 	crypto_shash_update(desc, aad, AAD_LEN);
-	crypto_shash_update(desc, data, data_len - CMAC_TLEN);
+	fc = (const __le16 *)aad;
+	if (ieee80211_is_beacon(*fc)) {
+		/* mask Timestamp field to zero */
+		crypto_shash_update(desc, zero, 8);
+		crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN);
+	} else {
+		crypto_shash_update(desc, data, data_len - CMAC_TLEN);
+	}
 	crypto_shash_finup(desc, zero, CMAC_TLEN, out);
 
 	memcpy(mic, out, CMAC_TLEN);
@@ -41,12 +49,21 @@ void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
 			    const u8 *data, size_t data_len, u8 *mic)
 {
 	SHASH_DESC_ON_STACK(desc, tfm);
+	const __le16 *fc;
 
 	desc->tfm = tfm;
 
 	crypto_shash_init(desc);
 	crypto_shash_update(desc, aad, AAD_LEN);
-	crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
+	fc = (const __le16 *)aad;
+	if (ieee80211_is_beacon(*fc)) {
+		/* mask Timestamp field to zero */
+		crypto_shash_update(desc, zero, 8);
+		crypto_shash_update(desc, data + 8,
+				    data_len - 8 - CMAC_TLEN_256);
+	} else {
+		crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
+	}
 	crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
 }
 
diff --git a/net/mac80211/aes_gmac.c b/net/mac80211/aes_gmac.c
index 363ad1c1dc0c..16ba09cb5def 100644
--- a/net/mac80211/aes_gmac.c
+++ b/net/mac80211/aes_gmac.c
@@ -17,10 +17,11 @@
 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];
+	struct scatterlist sg[5];
 	u8 *zero, *__aad, iv[AES_BLOCK_SIZE];
 	struct aead_request *aead_req;
 	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
+	const __le16 *fc;
 
 	if (data_len < GMAC_MIC_LEN)
 		return -EINVAL;
@@ -33,11 +34,22 @@ int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
 	__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);
+	fc = (const __le16 *)aad;
+	if (ieee80211_is_beacon(*fc)) {
+		/* mask Timestamp field to zero */
+		sg_init_table(sg, 5);
+		sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
+		sg_set_buf(&sg[1], zero, 8);
+		sg_set_buf(&sg[2], data + 8, data_len - 8 - GMAC_MIC_LEN);
+		sg_set_buf(&sg[3], zero, GMAC_MIC_LEN);
+		sg_set_buf(&sg[4], mic, GMAC_MIC_LEN);
+	} else {
+		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);
-- 
2.16.4