[PATCH] mac80211: aead api to reduce redundancy

From: Xiang Gao
Date: Tue Sep 26 2017 - 09:20:26 EST


Currently, the aes_ccm.c and aes_gcm.c are almost line by line copy of
each other. This patch reduce code redundancy by moving the code in these
two files to crypto/aead_api.c to make it a higher level aead api. The
file aes_ccm.c and aes_gcm.c are removed and all the functions there are
now implemented in their headers using the newly added aead api.

Signed-off-by: Xiang Gao <qasdfgtyuiop@xxxxxxxxx>
---
net/mac80211/Makefile | 3 +-
net/mac80211/{aes_gcm.c => aead_api.c} | 49 +++++++-------
net/mac80211/aead_api.h | 26 ++++++++
net/mac80211/aes_ccm.c | 115 ---------------------------------
net/mac80211/aes_ccm.h | 42 ++++++++----
net/mac80211/aes_gcm.h | 38 ++++++++---
net/mac80211/wpa.c | 12 ++--
7 files changed, 118 insertions(+), 167 deletions(-)
rename net/mac80211/{aes_gcm.c => aead_api.c} (55%)
create mode 100644 net/mac80211/aead_api.h
delete mode 100644 net/mac80211/aes_ccm.c

diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
index 282912245938..80f25ff2f24b 100644
--- a/net/mac80211/Makefile
+++ b/net/mac80211/Makefile
@@ -6,6 +6,7 @@ mac80211-y := \
driver-ops.o \
sta_info.o \
wep.o \
+ aead_api.o \
wpa.o \
scan.o offchannel.o \
ht.o agg-tx.o agg-rx.o \
@@ -15,8 +16,6 @@ mac80211-y := \
rate.o \
michael.o \
tkip.o \
- aes_ccm.o \
- aes_gcm.o \
aes_cmac.o \
aes_gmac.o \
fils_aead.o \
diff --git a/net/mac80211/aes_gcm.c b/net/mac80211/aead_api.c
similarity index 55%
rename from net/mac80211/aes_gcm.c
rename to net/mac80211/aead_api.c
index 8a4397cc1b08..6ac53d0c6977 100644
--- a/net/mac80211/aes_gcm.c
+++ b/net/mac80211/aead_api.c
@@ -1,7 +1,4 @@
-/*
- * Copyright 2014-2015, Qualcomm Atheros, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
+/* 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.
*/
@@ -9,43 +6,43 @@
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/err.h>
+#include <linux/scatterlist.h>
#include <crypto/aead.h>

-#include <net/mac80211.h>
-#include "key.h"
-#include "aes_gcm.h"
+#include "aead_api.h"

-int ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic)
+int aead_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
+ u8 *data, size_t data_len, u8 *auth)
{
struct scatterlist sg[3];
struct aead_request *aead_req;
int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
u8 *__aad;

- aead_req = kzalloc(reqsize + GCM_AAD_LEN, GFP_ATOMIC);
+ aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
if (!aead_req)
return -ENOMEM;

__aad = (u8 *)aead_req + reqsize;
- memcpy(__aad, aad, GCM_AAD_LEN);
+ memcpy(__aad, aad, aad_len);

sg_init_table(sg, 3);
- sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
+ sg_set_buf(&sg[0], __aad, aad_len);
sg_set_buf(&sg[1], data, data_len);
- sg_set_buf(&sg[2], mic, IEEE80211_GCMP_MIC_LEN);
+ sg_set_buf(&sg[2], auth, tfm->authsize);

aead_request_set_tfm(aead_req, tfm);
- aead_request_set_crypt(aead_req, sg, sg, data_len, j_0);
+ aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
aead_request_set_ad(aead_req, sg[0].length);

crypto_aead_encrypt(aead_req);
kzfree(aead_req);
+
return 0;
}

-int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic)
+int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
+ u8 *data, size_t data_len, u8 *auth)
{
struct scatterlist sg[3];
struct aead_request *aead_req;
@@ -56,21 +53,20 @@ int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
if (data_len == 0)
return -EINVAL;

- aead_req = kzalloc(reqsize + GCM_AAD_LEN, GFP_ATOMIC);
+ aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
if (!aead_req)
return -ENOMEM;

__aad = (u8 *)aead_req + reqsize;
- memcpy(__aad, aad, GCM_AAD_LEN);
+ memcpy(__aad, aad, aad_len);

sg_init_table(sg, 3);
sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
sg_set_buf(&sg[1], data, data_len);
- sg_set_buf(&sg[2], mic, IEEE80211_GCMP_MIC_LEN);
+ sg_set_buf(&sg[2], auth, tfm->authsize);

aead_request_set_tfm(aead_req, tfm);
- aead_request_set_crypt(aead_req, sg, sg,
- data_len + IEEE80211_GCMP_MIC_LEN, j_0);
+ aead_request_set_crypt(aead_req, sg, sg, data_len + tfm->authsize, b_0);
aead_request_set_ad(aead_req, sg[0].length);

err = crypto_aead_decrypt(aead_req);
@@ -79,20 +75,21 @@ int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
return err;
}

-struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(const u8 key[],
- size_t key_len)
+struct crypto_aead *
+aead_key_setup_encrypt(const char *alg, const u8 key[],
+ size_t key_len, size_t authsize)
{
struct crypto_aead *tfm;
int err;

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

err = crypto_aead_setkey(tfm, key, key_len);
if (err)
goto free_aead;
- err = crypto_aead_setauthsize(tfm, IEEE80211_GCMP_MIC_LEN);
+ err = crypto_aead_setauthsize(tfm, authsize);
if (err)
goto free_aead;

@@ -103,7 +100,7 @@ struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(const u8 key[],
return ERR_PTR(err);
}

-void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm)
+void aead_key_free(struct crypto_aead *tfm)
{
crypto_free_aead(tfm);
}
diff --git a/net/mac80211/aead_api.h b/net/mac80211/aead_api.h
new file mode 100644
index 000000000000..141a813d410c
--- /dev/null
+++ b/net/mac80211/aead_api.h
@@ -0,0 +1,26 @@
+/* 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.
+ */
+
+#ifndef _AEAD_API_H
+#define _AEAD_API_H
+
+#include <crypto/aead.h>
+#include <linux/crypto.h>
+
+struct crypto_aead *
+aead_key_setup_encrypt(const char *alg, const u8 key[],
+ size_t key_len, size_t authsize);
+
+int aead_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
+ size_t aad_len, u8 *data,
+ size_t data_len, u8 *auth);
+
+int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
+ size_t aad_len, u8 *data,
+ size_t data_len, u8 *auth);
+
+void aead_key_free(struct crypto_aead *tfm);
+
+#endif /* _AEAD_API_H */
diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c
deleted file mode 100644
index a4e0d59a40dd..000000000000
--- a/net/mac80211/aes_ccm.c
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright 2003-2004, Instant802 Networks, Inc.
- * Copyright 2005-2006, Devicescape Software, Inc.
- *
- * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@xxxxxxxxxx>
- *
- * 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 <net/mac80211.h>
-#include "key.h"
-#include "aes_ccm.h"
-
-int ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic,
- size_t mic_len)
-{
- struct scatterlist sg[3];
- struct aead_request *aead_req;
- int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
- u8 *__aad;
-
- aead_req = kzalloc(reqsize + CCM_AAD_LEN, GFP_ATOMIC);
- if (!aead_req)
- return -ENOMEM;
-
- __aad = (u8 *)aead_req + reqsize;
- memcpy(__aad, aad, CCM_AAD_LEN);
-
- sg_init_table(sg, 3);
- sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
- sg_set_buf(&sg[1], data, data_len);
- sg_set_buf(&sg[2], mic, mic_len);
-
- aead_request_set_tfm(aead_req, tfm);
- aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
- aead_request_set_ad(aead_req, sg[0].length);
-
- crypto_aead_encrypt(aead_req);
- kzfree(aead_req);
-
- return 0;
-}
-
-int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic,
- size_t mic_len)
-{
- struct scatterlist sg[3];
- struct aead_request *aead_req;
- int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
- u8 *__aad;
- int err;
-
- if (data_len == 0)
- return -EINVAL;
-
- aead_req = kzalloc(reqsize + CCM_AAD_LEN, GFP_ATOMIC);
- if (!aead_req)
- return -ENOMEM;
-
- __aad = (u8 *)aead_req + reqsize;
- memcpy(__aad, aad, CCM_AAD_LEN);
-
- sg_init_table(sg, 3);
- sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
- sg_set_buf(&sg[1], data, data_len);
- sg_set_buf(&sg[2], mic, mic_len);
-
- aead_request_set_tfm(aead_req, tfm);
- aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
- aead_request_set_ad(aead_req, sg[0].length);
-
- err = crypto_aead_decrypt(aead_req);
- kzfree(aead_req);
-
- return err;
-}
-
-struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
- size_t key_len,
- size_t mic_len)
-{
- struct crypto_aead *tfm;
- int err;
-
- tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(tfm))
- return tfm;
-
- err = crypto_aead_setkey(tfm, key, key_len);
- if (err)
- goto free_aead;
- err = crypto_aead_setauthsize(tfm, mic_len);
- if (err)
- goto free_aead;
-
- return tfm;
-
-free_aead:
- crypto_free_aead(tfm);
- return ERR_PTR(err);
-}
-
-void ieee80211_aes_key_free(struct crypto_aead *tfm)
-{
- crypto_free_aead(tfm);
-}
diff --git a/net/mac80211/aes_ccm.h b/net/mac80211/aes_ccm.h
index fcd3254c5cf0..e9b7ca0bde5b 100644
--- a/net/mac80211/aes_ccm.h
+++ b/net/mac80211/aes_ccm.h
@@ -10,19 +10,39 @@
#ifndef AES_CCM_H
#define AES_CCM_H

-#include <linux/crypto.h>
+#include "aead_api.h"

#define CCM_AAD_LEN 32

-struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
- size_t key_len,
- size_t mic_len);
-int ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic,
- size_t mic_len);
-int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic,
- size_t mic_len);
-void ieee80211_aes_key_free(struct crypto_aead *tfm);
+static inline struct crypto_aead *
+ieee80211_aes_key_setup_encrypt(const u8 key[], size_t key_len, size_t mic_len)
+{
+ return aead_key_setup_encrypt("ccm(aes)", key, key_len, mic_len);
+}
+
+static inline int
+ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm,
+ u8 *b_0, u8 *aad, u8 *data,
+ size_t data_len, u8 *mic)
+{
+ return aead_encrypt(tfm, b_0, aad + 2,
+ be16_to_cpup((__be16 *)aad),
+ data, data_len, mic);
+}
+
+static inline int
+ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm,
+ u8 *b_0, u8 *aad, u8 *data,
+ size_t data_len, u8 *mic)
+{
+ return aead_decrypt(tfm, b_0, aad + 2,
+ be16_to_cpup((__be16 *)aad),
+ data, data_len, mic);
+}
+
+static inline void ieee80211_aes_key_free(struct crypto_aead *tfm)
+{
+ return aead_key_free(tfm);
+}

#endif /* AES_CCM_H */
diff --git a/net/mac80211/aes_gcm.h b/net/mac80211/aes_gcm.h
index 55aed5352494..d2b096033009 100644
--- a/net/mac80211/aes_gcm.h
+++ b/net/mac80211/aes_gcm.h
@@ -9,16 +9,38 @@
#ifndef AES_GCM_H
#define AES_GCM_H

-#include <linux/crypto.h>
+#include "aead_api.h"

#define GCM_AAD_LEN 32

-int ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic);
-int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
- u8 *data, size_t data_len, u8 *mic);
-struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(const u8 key[],
- size_t key_len);
-void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm);
+static inline int ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm,
+ u8 *j_0, u8 *aad, u8 *data,
+ size_t data_len, u8 *mic)
+{
+ return aead_encrypt(tfm, j_0, aad + 2,
+ be16_to_cpup((__be16 *)aad),
+ data, data_len, mic);
+}
+
+static inline int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm,
+ u8 *j_0, u8 *aad, u8 *data,
+ size_t data_len, u8 *mic)
+{
+ return aead_decrypt(tfm, j_0, aad + 2,
+ be16_to_cpup((__be16 *)aad),
+ data, data_len, mic);
+}
+
+static inline struct crypto_aead *
+ieee80211_aes_gcm_key_setup_encrypt(const u8 key[], size_t key_len)
+{
+ return aead_key_setup_encrypt("gcm(aes)", key,
+ key_len, IEEE80211_GCMP_MIC_LEN);
+}
+
+static inline void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm)
+{
+ return aead_key_free(tfm);
+}

#endif /* AES_GCM_H */
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 0d722ea98a1b..390501bf9e31 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -464,7 +464,8 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
pos += IEEE80211_CCMP_HDR_LEN;
ccmp_special_blocks(skb, pn, b_0, aad);
return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
- skb_put(skb, mic_len), mic_len);
+ skb_put(skb,
+ key->u.ccmp.tfm->authsize));
}


@@ -540,10 +541,11 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
ccmp_special_blocks(skb, pn, b_0, aad);

if (ieee80211_aes_ccm_decrypt(
- key->u.ccmp.tfm, b_0, aad,
- skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
- data_len,
- skb->data + skb->len - mic_len, mic_len))
+ key->u.ccmp.tfm, b_0, aad,
+ skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
+ data_len,
+ skb->data + skb->len - key->u.ccmp.tfm->authsize
+ ))
return RX_DROP_UNUSABLE;
}

--
2.14.1