mac80211: remove wep dependency

PATCH Superseded John W. Linville 2 participants 6 messages Jul 6, 2010 – Jul 21, 2010 mac80211

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John W. Linville

author

2010-07-06 20:30 UTC #0 lore raw

PATCH 1/1 mac80211: remove wep dependency

The current mac80211 code assumes that WEP is always available. If WEP fails to initialize, ieee80211_register_hw will always fail.

In some cases (e.g. FIPS certification), the cryptography used by WEP is unavailable. However, in such cases there is no good reason why CCMP encryption (or even no link level encryption) cannot be used. So, this patch removes mac80211's assumption that WEP (and TKIP) will always be available for use.

Signed-off-by John W. Linville <[email protected]>

---
 net/mac80211/cfg.c  |    5 +++++
 net/mac80211/main.c |    5 +----
 net/mac80211/tkip.c |    8 ++++----
 net/mac80211/tkip.h |    2 +-
 net/mac80211/wep.c  |   18 ++++++++++++------
 net/mac80211/wep.h  |    2 +-
 net/mac80211/wpa.c  |    5 ++---
 7 files changed, 26 insertions(+), 19 deletions(-)

net/mac80211/cfg.c +5 -0

index e55970b..5b8b446 100644
@@ -143,6 +143,11 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 		return -EINVAL;
 	}
 
+	/* reject WEP and TKIP keys if WEP failed to initialize */
+	if ((alg == ALG_WEP || alg == ALG_TKIP) &&
+	    IS_ERR(sdata->local->wep_tx_tfm))
+		return -EINVAL;
+
 	key = ieee80211_key_alloc(alg, key_idx, params->key_len, params->key,
 				  params->seq_len, params->seq);
 	if (!key)

net/mac80211/main.c +1 -4

index edf7aff..0e95c75 100644
@@ -637,11 +637,9 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		goto fail_sta_info;
 
 	result = ieee80211_wep_init(local);
-	if (result < 0) {
+	if (result < 0)
 		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
 		       wiphy_name(local->hw.wiphy), result);
-		goto fail_wep;
-	}
 
 	rtnl_lock();

@@ -694,7 +692,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
  fail_rate:
 	rtnl_unlock();
 	ieee80211_wep_free(local);
- fail_wep:
 	sta_info_stop(local);
  fail_sta_info:
 	destroy_workqueue(local->workqueue);

net/mac80211/tkip.c +4 -4

index 7ef491e..e840c9c 100644
@@ -202,9 +202,9 @@ EXPORT_SYMBOL(ieee80211_get_tkip_key);
  * @payload_len is the length of payload (_not_ including IV/ICV length).
  * @ta is the transmitter addresses.
  */
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
-				 struct ieee80211_key *key,
-				 u8 *pos, size_t payload_len, u8 *ta)
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+				struct ieee80211_key *key,
+				u8 *pos, size_t payload_len, u8 *ta)
 {
 	u8 rc4key[16];
 	struct tkip_ctx *ctx = &key->u.tkip.tx;

@@ -216,7 +216,7 @@ void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
 
 	tkip_mixing_phase2(tk, ctx, ctx->iv16, rc4key);
 
-	ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
+	return ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
 }
 
 /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the

net/mac80211/tkip.h +1 -1

index d471438..7e83dee 100644
@@ -15,7 +15,7 @@
 
 u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, u16 iv16);
 
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
 				 struct ieee80211_key *key,
 				 u8 *pos, size_t payload_len, u8 *ta);
 enum {

net/mac80211/wep.c +12 -6

index 5f3a411..54263db 100644
@@ -122,19 +122,24 @@ static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
 /* Perform WEP encryption using given key. data buffer must have tailroom
  * for 4-byte ICV. data_len must not include this ICV. Note: this function
  * does _not_ add IV. data = RC4(data | CRC32(data)) */
-void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
-				size_t klen, u8 *data, size_t data_len)
+int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+			       size_t klen, u8 *data, size_t data_len)
 {
 	struct blkcipher_desc desc = { .tfm = tfm };
 	struct scatterlist sg;
 	__le32 icv;
 
+	if (IS_ERR(tfm))
+		return -1;
+
 	icv = cpu_to_le32(~crc32_le(~0, data, data_len));
 	put_unaligned(icv, (__le32 *)(data + data_len));
 
 	crypto_blkcipher_setkey(tfm, rc4key, klen);
 	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
 	crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);
+
+	return 0;
 }

@@ -168,10 +173,8 @@ int ieee80211_wep_encrypt(struct ieee80211_local *local,
 	/* Add room for ICV */
 	skb_put(skb, WEP_ICV_LEN);
 
-	ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
-				   iv + WEP_IV_LEN, len);
-
-	return 0;
+	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
+					  iv + WEP_IV_LEN, len);
 }

@@ -185,6 +188,9 @@ int ieee80211_wep_decrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
 	struct scatterlist sg;
 	__le32 crc;
 
+	if (IS_ERR(tfm))
+		return -1;
+
 	crypto_blkcipher_setkey(tfm, rc4key, klen);
 	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
 	crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);

net/mac80211/wep.h +1 -1

index fe29d7e..58654ee 100644
@@ -18,7 +18,7 @@
 
 int ieee80211_wep_init(struct ieee80211_local *local);
 void ieee80211_wep_free(struct ieee80211_local *local);
-void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
 				size_t klen, u8 *data, size_t data_len);
 int ieee80211_wep_encrypt(struct ieee80211_local *local,
 			  struct sk_buff *skb,

net/mac80211/wpa.c +2 -3

index a14e677..8d59d27 100644
@@ -183,9 +183,8 @@ static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 	skb_put(skb, TKIP_ICV_LEN);
 
 	hdr = (struct ieee80211_hdr *) skb->data;
-	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
-				    key, pos, len, hdr->addr2);
-	return 0;
+	return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
+					   key, pos, len, hdr->addr2);
 }

Signature · 1 line

1.7.1

John W. Linville

author

2010-07-07 18:45 UTC #1 lore raw

PATCH v2 1/1 mac80211: remove wep dependency

The current mac80211 code assumes that WEP is always available. If WEP fails to initialize, ieee80211_register_hw will always fail.

Signed-off-by John W. Linville <[email protected]>

---
v2 -> make it safe to call ieee80211_wep_free even if ieee80211_wep_init
had failed

 net/mac80211/cfg.c  |    5 +++++
 net/mac80211/main.c |    5 +----
 net/mac80211/tkip.c |    8 ++++----
 net/mac80211/tkip.h |    2 +-
 net/mac80211/wep.c  |   18 ++++++++++++------
 net/mac80211/wep.h  |    2 +-
 net/mac80211/wpa.c  |    5 ++---
 7 files changed, 26 insertions(+), 19 deletions(-)

net/mac80211/cfg.c +5 -0

index e55970b..5b8b446 100644
@@ -143,6 +143,11 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 		return -EINVAL;
 	}
 
+	/* reject WEP and TKIP keys if WEP failed to initialize */
+	if ((alg == ALG_WEP || alg == ALG_TKIP) &&
+	    IS_ERR(sdata->local->wep_tx_tfm))
+		return -EINVAL;
+
 	key = ieee80211_key_alloc(alg, key_idx, params->key_len, params->key,
 				  params->seq_len, params->seq);
 	if (!key)

net/mac80211/main.c +1 -4

index edf7aff..0e95c75 100644
@@ -637,11 +637,9 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		goto fail_sta_info;
 
 	result = ieee80211_wep_init(local);
-	if (result < 0) {
+	if (result < 0)
 		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
 		       wiphy_name(local->hw.wiphy), result);
-		goto fail_wep;
-	}
 
 	rtnl_lock();

@@ -694,7 +692,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
  fail_rate:
 	rtnl_unlock();
 	ieee80211_wep_free(local);
- fail_wep:
 	sta_info_stop(local);
  fail_sta_info:
 	destroy_workqueue(local->workqueue);

net/mac80211/tkip.c +4 -4

index 7ef491e..e840c9c 100644
@@ -202,9 +202,9 @@ EXPORT_SYMBOL(ieee80211_get_tkip_key);
  * @payload_len is the length of payload (_not_ including IV/ICV length).
  * @ta is the transmitter addresses.
  */
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
-				 struct ieee80211_key *key,
-				 u8 *pos, size_t payload_len, u8 *ta)
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+				struct ieee80211_key *key,
+				u8 *pos, size_t payload_len, u8 *ta)
 {
 	u8 rc4key[16];
 	struct tkip_ctx *ctx = &key->u.tkip.tx;

@@ -216,7 +216,7 @@ void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
 
 	tkip_mixing_phase2(tk, ctx, ctx->iv16, rc4key);
 
-	ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
+	return ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
 }
 
 /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the

net/mac80211/tkip.h +1 -1

index d471438..7e83dee 100644
@@ -15,7 +15,7 @@
 
 u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, u16 iv16);
 
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
 				 struct ieee80211_key *key,
 				 u8 *pos, size_t payload_len, u8 *ta);
 enum {

net/mac80211/wep.c +12 -6

index 5f3a411..54263db 100644
@@ -122,19 +122,24 @@ static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
 /* Perform WEP encryption using given key. data buffer must have tailroom
  * for 4-byte ICV. data_len must not include this ICV. Note: this function
  * does _not_ add IV. data = RC4(data | CRC32(data)) */
-void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
-				size_t klen, u8 *data, size_t data_len)
+int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+			       size_t klen, u8 *data, size_t data_len)
 {
 	struct blkcipher_desc desc = { .tfm = tfm };
 	struct scatterlist sg;
 	__le32 icv;
 
+	if (IS_ERR(tfm))
+		return -1;
+
 	icv = cpu_to_le32(~crc32_le(~0, data, data_len));
 	put_unaligned(icv, (__le32 *)(data + data_len));
 
 	crypto_blkcipher_setkey(tfm, rc4key, klen);
 	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
 	crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);
+
+	return 0;
 }

@@ -168,10 +173,8 @@ int ieee80211_wep_encrypt(struct ieee80211_local *local,
 	/* Add room for ICV */
 	skb_put(skb, WEP_ICV_LEN);
 
-	ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
-				   iv + WEP_IV_LEN, len);
-
-	return 0;
+	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
+					  iv + WEP_IV_LEN, len);
 }

@@ -185,6 +188,9 @@ int ieee80211_wep_decrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
 	struct scatterlist sg;
 	__le32 crc;
 
+	if (IS_ERR(tfm))
+		return -1;
+
 	crypto_blkcipher_setkey(tfm, rc4key, klen);
 	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
 	crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);

net/mac80211/wep.h +1 -1

index fe29d7e..58654ee 100644
@@ -18,7 +18,7 @@
 
 int ieee80211_wep_init(struct ieee80211_local *local);
 void ieee80211_wep_free(struct ieee80211_local *local);
-void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
 				size_t klen, u8 *data, size_t data_len);
 int ieee80211_wep_encrypt(struct ieee80211_local *local,
 			  struct sk_buff *skb,

net/mac80211/wpa.c +2 -3

index a14e677..8d59d27 100644
@@ -183,9 +183,8 @@ static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 	skb_put(skb, TKIP_ICV_LEN);
 
 	hdr = (struct ieee80211_hdr *) skb->data;
-	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
-				    key, pos, len, hdr->addr2);
-	return 0;
+	return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
+					   key, pos, len, hdr->addr2);
 }

Signature · 1 line

1.7.1

John W. Linville

author

2010-07-07 19:15 UTC #2 lore raw

PATCH v3 1/1 mac80211: remove wep dependency

The current mac80211 code assumes that WEP is always available. If WEP fails to initialize, ieee80211_register_hw will always fail.

Signed-off-by John W. Linville <[email protected]>

---
v3 -> actually post changed patch...
v2 -> make it safe to call ieee80211_wep_free even if ieee80211_wep_init
had failed

 net/mac80211/cfg.c  |    5 +++++
 net/mac80211/main.c |    5 +----
 net/mac80211/tkip.c |    8 ++++----
 net/mac80211/tkip.h |    2 +-
 net/mac80211/wep.c  |   24 ++++++++++++++++--------
 net/mac80211/wep.h  |    2 +-
 net/mac80211/wpa.c  |    5 ++---
 7 files changed, 30 insertions(+), 21 deletions(-)

net/mac80211/cfg.c +5 -0

index e55970b..5b8b446 100644
@@ -143,6 +143,11 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 		return -EINVAL;
 	}
 
+	/* reject WEP and TKIP keys if WEP failed to initialize */
+	if ((alg == ALG_WEP || alg == ALG_TKIP) &&
+	    IS_ERR(sdata->local->wep_tx_tfm))
+		return -EINVAL;
+
 	key = ieee80211_key_alloc(alg, key_idx, params->key_len, params->key,
 				  params->seq_len, params->seq);
 	if (!key)

net/mac80211/main.c +1 -4

index edf7aff..0e95c75 100644
@@ -637,11 +637,9 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		goto fail_sta_info;
 
 	result = ieee80211_wep_init(local);
-	if (result < 0) {
+	if (result < 0)
 		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
 		       wiphy_name(local->hw.wiphy), result);
-		goto fail_wep;
-	}
 
 	rtnl_lock();

@@ -694,7 +692,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
  fail_rate:
 	rtnl_unlock();
 	ieee80211_wep_free(local);
- fail_wep:
 	sta_info_stop(local);
  fail_sta_info:
 	destroy_workqueue(local->workqueue);

net/mac80211/tkip.c +4 -4

index 7ef491e..e840c9c 100644
@@ -202,9 +202,9 @@ EXPORT_SYMBOL(ieee80211_get_tkip_key);
  * @payload_len is the length of payload (_not_ including IV/ICV length).
  * @ta is the transmitter addresses.
  */
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
-				 struct ieee80211_key *key,
-				 u8 *pos, size_t payload_len, u8 *ta)
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+				struct ieee80211_key *key,
+				u8 *pos, size_t payload_len, u8 *ta)
 {
 	u8 rc4key[16];
 	struct tkip_ctx *ctx = &key->u.tkip.tx;

@@ -216,7 +216,7 @@ void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
 
 	tkip_mixing_phase2(tk, ctx, ctx->iv16, rc4key);
 
-	ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
+	return ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
 }
 
 /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the

net/mac80211/tkip.h +1 -1

index d471438..7e83dee 100644
@@ -15,7 +15,7 @@
 
 u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, u16 iv16);
 
-void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
 				 struct ieee80211_key *key,
 				 u8 *pos, size_t payload_len, u8 *ta);
 enum {

net/mac80211/wep.c +16 -8

index 5f3a411..6d133b6 100644
@@ -47,8 +47,10 @@ int ieee80211_wep_init(struct ieee80211_local *local)
 
 void ieee80211_wep_free(struct ieee80211_local *local)
 {
-	crypto_free_blkcipher(local->wep_tx_tfm);
-	crypto_free_blkcipher(local->wep_rx_tfm);
+	if (!IS_ERR(local->wep_tx_tfm))
+		crypto_free_blkcipher(local->wep_tx_tfm);
+	if (!IS_ERR(local->wep_rx_tfm))
+		crypto_free_blkcipher(local->wep_rx_tfm);
 }
 
 static inline bool ieee80211_wep_weak_iv(u32 iv, int keylen)

@@ -122,19 +124,24 @@ static void ieee80211_wep_remove_iv(struct ieee80211_local *local,
 /* Perform WEP encryption using given key. data buffer must have tailroom
  * for 4-byte ICV. data_len must not include this ICV. Note: this function
  * does _not_ add IV. data = RC4(data | CRC32(data)) */
-void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
-				size_t klen, u8 *data, size_t data_len)
+int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+			       size_t klen, u8 *data, size_t data_len)
 {
 	struct blkcipher_desc desc = { .tfm = tfm };
 	struct scatterlist sg;
 	__le32 icv;
 
+	if (IS_ERR(tfm))
+		return -1;
+
 	icv = cpu_to_le32(~crc32_le(~0, data, data_len));
 	put_unaligned(icv, (__le32 *)(data + data_len));
 
 	crypto_blkcipher_setkey(tfm, rc4key, klen);
 	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
 	crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);
+
+	return 0;
 }

@@ -168,10 +175,8 @@ int ieee80211_wep_encrypt(struct ieee80211_local *local,
 	/* Add room for ICV */
 	skb_put(skb, WEP_ICV_LEN);
 
-	ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
-				   iv + WEP_IV_LEN, len);
-
-	return 0;
+	return ieee80211_wep_encrypt_data(local->wep_tx_tfm, rc4key, keylen + 3,
+					  iv + WEP_IV_LEN, len);
 }

@@ -185,6 +190,9 @@ int ieee80211_wep_decrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
 	struct scatterlist sg;
 	__le32 crc;
 
+	if (IS_ERR(tfm))
+		return -1;
+
 	crypto_blkcipher_setkey(tfm, rc4key, klen);
 	sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
 	crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);

net/mac80211/wep.h +1 -1

index fe29d7e..58654ee 100644
@@ -18,7 +18,7 @@
 
 int ieee80211_wep_init(struct ieee80211_local *local);
 void ieee80211_wep_free(struct ieee80211_local *local);
-void ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
 				size_t klen, u8 *data, size_t data_len);
 int ieee80211_wep_encrypt(struct ieee80211_local *local,
 			  struct sk_buff *skb,

net/mac80211/wpa.c +2 -3

index a14e677..8d59d27 100644
@@ -183,9 +183,8 @@ static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 	skb_put(skb, TKIP_ICV_LEN);
 
 	hdr = (struct ieee80211_hdr *) skb->data;
-	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
-				    key, pos, len, hdr->addr2);
-	return 0;
+	return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
+					   key, pos, len, hdr->addr2);
 }

Signature · 1 line

1.7.1

Johannes Berg

maintainer

2010-07-20 10:59 UTC #3 lore raw

Quoted 9 lines · John W. Linville

The current mac80211 code assumes that WEP is always available. If WEP fails to initialize, ieee80211_register_hw will always fail.
In some cases (e.g. FIPS certification), the cryptography used by WEP is unavailable. However, in such cases there is no good reason why CCMP encryption (or even no link level encryption) cannot be used. So, this patch removes mac80211's assumption that WEP (and TKIP) will always be available for use.

Quoted 5 lines

Signed-off-by John W. Linville <[email protected]>
---
v3 -> actually post changed patch...
v2 -> make it safe to call ieee80211_wep_free even if ieee80211_wep_init
had failed

I think this is missing a change like this:

net/mac80211/cfg.c +4 -0

@@ -1228,6 +1228,10 @@ static int ieee80211_scan(struct wiphy *wiphy,
 static int ieee80211_auth(struct wiphy *wiphy, struct net_device *dev,
 			  struct cfg80211_auth_request *req)
 {
+	if (req->auth_type == NL80211_AUTHTYPE_SHARED_KEY &&
+	    IS_ERR(sdata->local->wep_tx_tfm))
+		return -EINVAL;
+
 	return ieee80211_mgd_auth(IEEE80211_DEV_TO_SUB_IF(dev), req);
 }

since otherwise you could end up trying to encrypt the auth frame with the uninitialised WEP TFM?

johannes

John W. Linville

author

2010-07-20 19:00 UTC #4 lore raw

Quoted 32 lines · Johannes Berg

Quoted 9 lines · John W. Linville
The current mac80211 code assumes that WEP is always available. If WEP fails to initialize, ieee80211_register_hw will always fail.
In some cases (e.g. FIPS certification), the cryptography used by WEP is unavailable. However, in such cases there is no good reason why CCMP encryption (or even no link level encryption) cannot be used. So, this patch removes mac80211's assumption that WEP (and TKIP) will always be available for use.
Quoted 5 lines
Signed-off-by John W. Linville <[email protected]>
---
v3 -> actually post changed patch...
v2 -> make it safe to call ieee80211_wep_free even if ieee80211_wep_init
had failed
I think this is missing a change like this:
net/mac80211/cfg.c +4 -0
@@ -1228,6 +1228,10 @@ static int ieee80211_scan(struct wiphy *wiphy,
 static int ieee80211_auth(struct wiphy *wiphy, struct net_device *dev,
 			  struct cfg80211_auth_request *req)
 {
+	if (req->auth_type == NL80211_AUTHTYPE_SHARED_KEY &&
+	    IS_ERR(sdata->local->wep_tx_tfm))
+		return -EINVAL;
+
 	return ieee80211_mgd_auth(IEEE80211_DEV_TO_SUB_IF(dev), req);
 }
 

Quoted 2 lines

since otherwise you could end up trying to encrypt the auth frame with the uninitialised WEP TFM?

Yes, I think that makes sense. The check in ieee80211_wep_encrypt_data will make it safe either way, but that will trigger a warning in ieee80211_send_auth and leave us unable to return an error to the ieee80211_auth caller. Also, it will send the auth request unencrypted...

Care to send that as a "real" patch? :-)

John

Signature · 2 lines

John W. Linville		Someday the world will need a hero, and you
[email protected]			might be all we have.  Be ready.

Johannes Berg

maintainer

2010-07-21 08:09 UTC #5 lore raw

PATCH 1/1 mac80211: refuse shared key auth when WEP is unavailable

From: Johannes Berg <[email protected]>

When WEP is not available, we should reject shared key authentication because it could never succeed.

Signed-off-by Johannes Berg <[email protected]>

---
 net/mac80211/mlme.c |    2 ++
 1 file changed, 2 insertions(+)

net/mac80211/mlme.c +2 -0

@@ -2030,6 +2030,8 @@ int ieee80211_mgd_auth(struct ieee80211_
 		auth_alg = WLAN_AUTH_OPEN;
 		break;
 	case NL80211_AUTHTYPE_SHARED_KEY:
+		if (IS_ERR(sdata->local->wep_tx_tfm))
+			return -EOPNOTSUPP;
 		auth_alg = WLAN_AUTH_SHARED_KEY;
 		break;
 	case NL80211_AUTHTYPE_FT: