[PATCH 1/2] staging: rtl8192u: ieee80211: ieee80211_crypt_ccmp.c: Use crypto API ccm(aes)
From: Christina Quast
Date: Fri Aug 16 2019 - 03:11:21 EST
Use ccm(aes) aead transform instead of invoking the AES block cipher
block by block.
Signed-off-by: Christina Quast <contact@xxxxxxxxxxxxxxxxxx>
---
drivers/staging/rtl8192u/Kconfig | 2 +
.../rtl8192u/ieee80211/ieee80211_crypt_ccmp.c | 187 ++++++++----------
2 files changed, 81 insertions(+), 108 deletions(-)
diff --git a/drivers/staging/rtl8192u/Kconfig b/drivers/staging/rtl8192u/Kconfig
index 22c2165e8b1c..1edca5c304fb 100644
--- a/drivers/staging/rtl8192u/Kconfig
+++ b/drivers/staging/rtl8192u/Kconfig
@@ -6,3 +6,5 @@ config RTL8192U
select WIRELESS_EXT
select WEXT_PRIV
select CRYPTO
+ select CRYPTO_AES
+ select CRYPTO_CCM
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_crypt_ccmp.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_crypt_ccmp.c
index d7188b3f3190..aecee42be95e 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_crypt_ccmp.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_crypt_ccmp.c
@@ -19,6 +19,7 @@
#include "ieee80211.h"
#include <linux/crypto.h>
+#include <crypto/aead.h>
#include <linux/scatterlist.h>
MODULE_AUTHOR("Jouni Malinen");
@@ -44,20 +45,13 @@ struct ieee80211_ccmp_data {
int key_idx;
- struct crypto_tfm *tfm;
+ struct crypto_aead *tfm;
/* scratch buffers for virt_to_page() (crypto API) */
- u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
- tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
- u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
+ u8 tx_aad[2 * AES_BLOCK_LEN];
+ u8 rx_aad[2 * AES_BLOCK_LEN];
};
-static void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
- const u8 pt[16], u8 ct[16])
-{
- crypto_cipher_encrypt_one((void *)tfm, ct, pt);
-}
-
static void *ieee80211_ccmp_init(int key_idx)
{
struct ieee80211_ccmp_data *priv;
@@ -67,7 +61,7 @@ static void *ieee80211_ccmp_init(int key_idx)
goto fail;
priv->key_idx = key_idx;
- priv->tfm = (void *)crypto_alloc_cipher("aes", 0, 0);
+ priv->tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(priv->tfm)) {
pr_debug("ieee80211_crypt_ccmp: could not allocate crypto API aes\n");
priv->tfm = NULL;
@@ -79,7 +73,7 @@ static void *ieee80211_ccmp_init(int key_idx)
fail:
if (priv) {
if (priv->tfm)
- crypto_free_cipher((void *)priv->tfm);
+ crypto_free_aead(priv->tfm);
kfree(priv);
}
@@ -91,28 +85,17 @@ static void ieee80211_ccmp_deinit(void *priv)
struct ieee80211_ccmp_data *_priv = priv;
if (_priv && _priv->tfm)
- crypto_free_cipher((void *)_priv->tfm);
+ crypto_free_aead(_priv->tfm);
kfree(priv);
}
-static inline void xor_block(u8 *b, u8 *a, size_t len)
-{
- int i;
-
- for (i = 0; i < len; i++)
- b[i] ^= a[i];
-}
-
-static void ccmp_init_blocks(struct crypto_tfm *tfm,
- struct rtl_80211_hdr_4addr *hdr,
- u8 *pn, size_t dlen, u8 *b0, u8 *auth,
- u8 *s0)
+static int ccmp_init_iv_and_aad(struct rtl_80211_hdr_4addr *hdr,
+ u8 *pn, u8 *iv, u8 *aad)
{
u8 *pos, qc = 0;
size_t aad_len;
u16 fc;
int a4_included, qc_included;
- u8 aad[2 * AES_BLOCK_LEN];
fc = le16_to_cpu(hdr->frame_ctl);
a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
@@ -133,18 +116,20 @@ static void ccmp_init_blocks(struct crypto_tfm *tfm,
qc = *pos & 0x0f;
aad_len += 2;
}
- /* CCM Initial Block:
- * Flag (Include authentication header, M=3 (8-octet MIC),
- * L=1 (2-octet Dlen))
- * Nonce: 0x00 | A2 | PN
- * Dlen
+
+ /* 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 the same vector. 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.
*/
- b0[0] = 0x59;
- b0[1] = qc;
- memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
- memcpy(b0 + 8, pn, CCMP_PN_LEN);
- b0[14] = (dlen >> 8) & 0xff;
- b0[15] = dlen & 0xff;
+ iv[0] = 0x1;
+
+ /* Nonce: QC | A2 | PN */
+ iv[1] = qc;
+ memcpy(iv + 2, hdr->addr2, ETH_ALEN);
+ memcpy(iv + 8, pn, CCMP_PN_LEN);
/* AAD:
* FC with bits 4..6 and 11..13 masked to zero; 14 is always one
@@ -154,32 +139,21 @@ static void ccmp_init_blocks(struct crypto_tfm *tfm,
* QC (if present)
*/
pos = (u8 *)hdr;
- aad[0] = 0; /* aad_len >> 8 */
- aad[1] = aad_len & 0xff;
- aad[2] = pos[0] & 0x8f;
- aad[3] = pos[1] & 0xc7;
- memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
+ aad[0] = pos[0] & 0x8f;
+ aad[1] = pos[1] & 0xc7;
+ memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN);
pos = (u8 *)&hdr->seq_ctl;
- aad[22] = pos[0] & 0x0f;
- aad[23] = 0; /* all bits masked */
- memset(aad + 24, 0, 8);
+ aad[20] = pos[0] & 0x0f;
+ aad[21] = 0; /* all bits masked */
+ memset(aad + 22, 0, 8);
if (a4_included)
- memcpy(aad + 24, hdr->addr4, ETH_ALEN);
+ memcpy(aad + 22, hdr->addr4, ETH_ALEN);
if (qc_included) {
- aad[a4_included ? 30 : 24] = qc;
+ aad[a4_included ? 28 : 22] = qc;
/* rest of QC masked */
}
- /* Start with the first block and AAD */
- ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
- xor_block(auth, aad, AES_BLOCK_LEN);
- ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
- xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
- ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
- b0[0] &= 0x07;
- b0[14] = 0;
- b0[15] = 0;
- ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
+ return aad_len;
}
static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
@@ -220,36 +194,34 @@ static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
hdr = (struct rtl_80211_hdr_4addr *)skb->data;
if (!tcb_desc->bHwSec) {
- int blocks, last, len;
- u8 *mic;
- u8 *b0 = key->tx_b0;
- u8 *b = key->tx_b;
- u8 *e = key->tx_e;
- u8 *s0 = key->tx_s0;
+ struct aead_request *req;
+ struct scatterlist sg[2];
+ u8 *aad = key->tx_aad;
+ u8 iv[AES_BLOCK_LEN];
+ int aad_len, ret;
+ size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN;
- /* mic is moved to here by john */
- mic = skb_put(skb, CCMP_MIC_LEN);
+ req = aead_request_alloc(key->tfm, GFP_ATOMIC);
+ if (!req)
+ return -ENOMEM;
- ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
+ aad_len = ccmp_init_iv_and_aad(hdr, key->tx_pn, iv, aad);
- blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
- last = data_len % AES_BLOCK_LEN;
+ skb_put(skb, CCMP_MIC_LEN);
- for (i = 1; i <= blocks; i++) {
- len = (i == blocks && last) ? last : AES_BLOCK_LEN;
- /* Authentication */
- xor_block(b, pos, len);
- ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
- /* Encryption, with counter */
- b0[14] = (i >> 8) & 0xff;
- b0[15] = i & 0xff;
- ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
- xor_block(pos, e, len);
- pos += len;
- }
+ sg_init_table(sg, 2);
+ sg_set_buf(&sg[0], aad, aad_len);
+ sg_set_buf(&sg[1], skb->data + hdr_len + CCMP_HDR_LEN,
+ data_len + CCMP_MIC_LEN);
- for (i = 0; i < CCMP_MIC_LEN; i++)
- mic[i] = b[i] ^ s0[i];
+ aead_request_set_callback(req, 0, NULL, NULL);
+ aead_request_set_ad(req, aad_len);
+ aead_request_set_crypt(req, sg, sg, data_len, iv);
+
+ ret = crypto_aead_encrypt(req);
+ aead_request_free(req);
+
+ return ret;
}
return 0;
}
@@ -309,33 +281,31 @@ static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
return -4;
}
if (!tcb_desc->bHwSec) {
- size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
- u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
- u8 *b0 = key->rx_b0;
- u8 *b = key->rx_b;
- u8 *a = key->rx_a;
- int i, blocks, last, len;
+ struct aead_request *req;
+ struct scatterlist sg[2];
+ u8 *aad = key->rx_aad;
+ u8 iv[AES_BLOCK_LEN];
+ int aad_len, ret;
+ size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN;
- ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
- xor_block(mic, b, CCMP_MIC_LEN);
+ req = aead_request_alloc(key->tfm, GFP_ATOMIC);
+ if (!req)
+ return -ENOMEM;
- blocks = DIV_ROUND_UP(data_len, AES_BLOCK_LEN);
- last = data_len % AES_BLOCK_LEN;
+ aad_len = ccmp_init_iv_and_aad(hdr, pn, iv, aad);
- for (i = 1; i <= blocks; i++) {
- len = (i == blocks && last) ? last : AES_BLOCK_LEN;
- /* Decrypt, with counter */
- b0[14] = (i >> 8) & 0xff;
- b0[15] = i & 0xff;
- ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
- xor_block(pos, b, len);
- /* Authentication */
- xor_block(a, pos, len);
- ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
- pos += len;
- }
+ sg_init_table(sg, 2);
+ sg_set_buf(&sg[0], aad, aad_len);
+ sg_set_buf(&sg[1], pos, data_len);
- if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
+ aead_request_set_callback(req, 0, NULL, NULL);
+ aead_request_set_ad(req, aad_len);
+ aead_request_set_crypt(req, sg, sg, data_len, iv);
+
+ ret = crypto_aead_decrypt(req);
+ aead_request_free(req);
+
+ if (ret) {
if (net_ratelimit()) {
netdev_dbg(skb->dev, "CCMP: decrypt failed: STA=%pM\n",
hdr->addr2);
@@ -358,12 +328,11 @@ static int ieee80211_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
{
struct ieee80211_ccmp_data *data = priv;
int keyidx;
- struct crypto_tfm *tfm = data->tfm;
+ struct crypto_aead *tfm = data->tfm;
keyidx = data->key_idx;
memset(data, 0, sizeof(*data));
data->key_idx = keyidx;
- data->tfm = tfm;
if (len == CCMP_TK_LEN) {
memcpy(data->key, key, CCMP_TK_LEN);
data->key_set = 1;
@@ -375,7 +344,9 @@ static int ieee80211_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
data->rx_pn[4] = seq[1];
data->rx_pn[5] = seq[0];
}
- crypto_cipher_setkey((void *)data->tfm, data->key, CCMP_TK_LEN);
+ if (crypto_aead_setauthsize(tfm, CCMP_MIC_LEN) ||
+ crypto_aead_setkey(tfm, data->key, CCMP_TK_LEN))
+ return -1;
} else if (len == 0) {
data->key_set = 0;
} else {
--
2.20.1