mac80211: port CCMP to cryptoapi's CCM driver
Use the generic CCM aead chaining mode driver rather than a local implementation that sits right on top of the core AES cipher. This allows the use of accelerated implementations of either CCM as a whole or the CTR mode which it encapsulates. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Ard Biesheuvel
Johannes Berg
parent
fa1fb9cb1c
commit
7ec7c4a9a6
|
|
@ -4,6 +4,7 @@ config MAC80211
|
|||
select CRYPTO
|
||||
select CRYPTO_ARC4
|
||||
select CRYPTO_AES
|
||||
select CRYPTO_CCM
|
||||
select CRC32
|
||||
select AVERAGE
|
||||
---help---
|
||||
|
|
|
|||
|
|
@ -2,6 +2,8 @@
|
|||
* Copyright 2003-2004, Instant802 Networks, Inc.
|
||||
* Copyright 2005-2006, Devicescape Software, Inc.
|
||||
*
|
||||
* Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
|
||||
*
|
||||
* 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.
|
||||
|
|
@ -17,134 +19,75 @@
|
|||
#include "key.h"
|
||||
#include "aes_ccm.h"
|
||||
|
||||
static void aes_ccm_prepare(struct crypto_cipher *tfm, u8 *scratch, u8 *a)
|
||||
void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
|
||||
u8 *data, size_t data_len, u8 *mic)
|
||||
{
|
||||
int i;
|
||||
u8 *b_0, *aad, *b, *s_0;
|
||||
struct scatterlist assoc, pt, ct[2];
|
||||
struct {
|
||||
struct aead_request req;
|
||||
u8 priv[crypto_aead_reqsize(tfm)];
|
||||
} aead_req;
|
||||
|
||||
b_0 = scratch + 3 * AES_BLOCK_SIZE;
|
||||
aad = scratch + 4 * AES_BLOCK_SIZE;
|
||||
b = scratch;
|
||||
s_0 = scratch + AES_BLOCK_SIZE;
|
||||
memset(&aead_req, 0, sizeof(aead_req));
|
||||
|
||||
crypto_cipher_encrypt_one(tfm, b, b_0);
|
||||
sg_init_one(&pt, data, data_len);
|
||||
sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
|
||||
sg_init_table(ct, 2);
|
||||
sg_set_buf(&ct[0], data, data_len);
|
||||
sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);
|
||||
|
||||
/* Extra Authenticate-only data (always two AES blocks) */
|
||||
for (i = 0; i < AES_BLOCK_SIZE; i++)
|
||||
aad[i] ^= b[i];
|
||||
crypto_cipher_encrypt_one(tfm, b, aad);
|
||||
aead_request_set_tfm(&aead_req.req, tfm);
|
||||
aead_request_set_assoc(&aead_req.req, &assoc, assoc.length);
|
||||
aead_request_set_crypt(&aead_req.req, &pt, ct, data_len, b_0);
|
||||
|
||||
aad += AES_BLOCK_SIZE;
|
||||
|
||||
for (i = 0; i < AES_BLOCK_SIZE; i++)
|
||||
aad[i] ^= b[i];
|
||||
crypto_cipher_encrypt_one(tfm, a, aad);
|
||||
|
||||
/* Mask out bits from auth-only-b_0 */
|
||||
b_0[0] &= 0x07;
|
||||
|
||||
/* S_0 is used to encrypt T (= MIC) */
|
||||
b_0[14] = 0;
|
||||
b_0[15] = 0;
|
||||
crypto_cipher_encrypt_one(tfm, s_0, b_0);
|
||||
crypto_aead_encrypt(&aead_req.req);
|
||||
}
|
||||
|
||||
|
||||
void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch,
|
||||
u8 *data, size_t data_len,
|
||||
u8 *cdata, u8 *mic)
|
||||
int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
|
||||
u8 *data, size_t data_len, u8 *mic)
|
||||
{
|
||||
int i, j, last_len, num_blocks;
|
||||
u8 *pos, *cpos, *b, *s_0, *e, *b_0;
|
||||
struct scatterlist assoc, pt, ct[2];
|
||||
struct {
|
||||
struct aead_request req;
|
||||
u8 priv[crypto_aead_reqsize(tfm)];
|
||||
} aead_req;
|
||||
|
||||
b = scratch;
|
||||
s_0 = scratch + AES_BLOCK_SIZE;
|
||||
e = scratch + 2 * AES_BLOCK_SIZE;
|
||||
b_0 = scratch + 3 * AES_BLOCK_SIZE;
|
||||
memset(&aead_req, 0, sizeof(aead_req));
|
||||
|
||||
num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_SIZE);
|
||||
last_len = data_len % AES_BLOCK_SIZE;
|
||||
aes_ccm_prepare(tfm, scratch, b);
|
||||
sg_init_one(&pt, data, data_len);
|
||||
sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
|
||||
sg_init_table(ct, 2);
|
||||
sg_set_buf(&ct[0], data, data_len);
|
||||
sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);
|
||||
|
||||
/* Process payload blocks */
|
||||
pos = data;
|
||||
cpos = cdata;
|
||||
for (j = 1; j <= num_blocks; j++) {
|
||||
int blen = (j == num_blocks && last_len) ?
|
||||
last_len : AES_BLOCK_SIZE;
|
||||
aead_request_set_tfm(&aead_req.req, tfm);
|
||||
aead_request_set_assoc(&aead_req.req, &assoc, assoc.length);
|
||||
aead_request_set_crypt(&aead_req.req, ct, &pt,
|
||||
data_len + IEEE80211_CCMP_MIC_LEN, b_0);
|
||||
|
||||
/* Authentication followed by encryption */
|
||||
for (i = 0; i < blen; i++)
|
||||
b[i] ^= pos[i];
|
||||
crypto_cipher_encrypt_one(tfm, b, b);
|
||||
|
||||
b_0[14] = (j >> 8) & 0xff;
|
||||
b_0[15] = j & 0xff;
|
||||
crypto_cipher_encrypt_one(tfm, e, b_0);
|
||||
for (i = 0; i < blen; i++)
|
||||
*cpos++ = *pos++ ^ e[i];
|
||||
}
|
||||
|
||||
for (i = 0; i < IEEE80211_CCMP_MIC_LEN; i++)
|
||||
mic[i] = b[i] ^ s_0[i];
|
||||
return crypto_aead_decrypt(&aead_req.req);
|
||||
}
|
||||
|
||||
|
||||
int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch,
|
||||
u8 *cdata, size_t data_len, u8 *mic, u8 *data)
|
||||
struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[])
|
||||
{
|
||||
int i, j, last_len, num_blocks;
|
||||
u8 *pos, *cpos, *b, *s_0, *a, *b_0;
|
||||
struct crypto_aead *tfm;
|
||||
int err;
|
||||
|
||||
b = scratch;
|
||||
s_0 = scratch + AES_BLOCK_SIZE;
|
||||
a = scratch + 2 * AES_BLOCK_SIZE;
|
||||
b_0 = scratch + 3 * AES_BLOCK_SIZE;
|
||||
tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
|
||||
if (IS_ERR(tfm))
|
||||
return tfm;
|
||||
|
||||
num_blocks = DIV_ROUND_UP(data_len, AES_BLOCK_SIZE);
|
||||
last_len = data_len % AES_BLOCK_SIZE;
|
||||
aes_ccm_prepare(tfm, scratch, a);
|
||||
err = crypto_aead_setkey(tfm, key, WLAN_KEY_LEN_CCMP);
|
||||
if (!err)
|
||||
err = crypto_aead_setauthsize(tfm, IEEE80211_CCMP_MIC_LEN);
|
||||
if (!err)
|
||||
return tfm;
|
||||
|
||||
/* Process payload blocks */
|
||||
cpos = cdata;
|
||||
pos = data;
|
||||
for (j = 1; j <= num_blocks; j++) {
|
||||
int blen = (j == num_blocks && last_len) ?
|
||||
last_len : AES_BLOCK_SIZE;
|
||||
|
||||
/* Decryption followed by authentication */
|
||||
b_0[14] = (j >> 8) & 0xff;
|
||||
b_0[15] = j & 0xff;
|
||||
crypto_cipher_encrypt_one(tfm, b, b_0);
|
||||
for (i = 0; i < blen; i++) {
|
||||
*pos = *cpos++ ^ b[i];
|
||||
a[i] ^= *pos++;
|
||||
}
|
||||
crypto_cipher_encrypt_one(tfm, a, a);
|
||||
}
|
||||
|
||||
for (i = 0; i < IEEE80211_CCMP_MIC_LEN; i++) {
|
||||
if ((mic[i] ^ s_0[i]) != a[i])
|
||||
return -1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
crypto_free_aead(tfm);
|
||||
return ERR_PTR(err);
|
||||
}
|
||||
|
||||
|
||||
struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[])
|
||||
void ieee80211_aes_key_free(struct crypto_aead *tfm)
|
||||
{
|
||||
struct crypto_cipher *tfm;
|
||||
|
||||
tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
|
||||
if (!IS_ERR(tfm))
|
||||
crypto_cipher_setkey(tfm, key, WLAN_KEY_LEN_CCMP);
|
||||
|
||||
return tfm;
|
||||
}
|
||||
|
||||
|
||||
void ieee80211_aes_key_free(struct crypto_cipher *tfm)
|
||||
{
|
||||
crypto_free_cipher(tfm);
|
||||
crypto_free_aead(tfm);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -12,13 +12,11 @@
|
|||
|
||||
#include <linux/crypto.h>
|
||||
|
||||
struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[]);
|
||||
void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch,
|
||||
u8 *data, size_t data_len,
|
||||
u8 *cdata, u8 *mic);
|
||||
int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch,
|
||||
u8 *cdata, size_t data_len,
|
||||
u8 *mic, u8 *data);
|
||||
void ieee80211_aes_key_free(struct crypto_cipher *tfm);
|
||||
struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[]);
|
||||
void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
|
||||
u8 *data, size_t data_len, u8 *mic);
|
||||
int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
|
||||
u8 *data, size_t data_len, u8 *mic);
|
||||
void ieee80211_aes_key_free(struct crypto_aead *tfm);
|
||||
|
||||
#endif /* AES_CCM_H */
|
||||
|
|
|
|||
|
|
@ -83,7 +83,7 @@ struct ieee80211_key {
|
|||
* Management frames.
|
||||
*/
|
||||
u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_CCMP_PN_LEN];
|
||||
struct crypto_cipher *tfm;
|
||||
struct crypto_aead *tfm;
|
||||
u32 replays; /* dot11RSNAStatsCCMPReplays */
|
||||
} ccmp;
|
||||
struct {
|
||||
|
|
|
|||
|
|
@ -301,22 +301,16 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
|
|||
}
|
||||
|
||||
|
||||
static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
|
||||
static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
|
||||
int encrypted)
|
||||
{
|
||||
__le16 mask_fc;
|
||||
int a4_included, mgmt;
|
||||
u8 qos_tid;
|
||||
u8 *b_0, *aad;
|
||||
u16 data_len, len_a;
|
||||
u16 len_a;
|
||||
unsigned int hdrlen;
|
||||
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
|
||||
|
||||
memset(scratch, 0, 6 * AES_BLOCK_SIZE);
|
||||
|
||||
b_0 = scratch + 3 * AES_BLOCK_SIZE;
|
||||
aad = scratch + 4 * AES_BLOCK_SIZE;
|
||||
|
||||
/*
|
||||
* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
|
||||
* Retry, PwrMgt, MoreData; set Protected
|
||||
|
|
@ -338,20 +332,21 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
|
|||
else
|
||||
qos_tid = 0;
|
||||
|
||||
data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN;
|
||||
if (encrypted)
|
||||
data_len -= IEEE80211_CCMP_MIC_LEN;
|
||||
/* 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 this vector b_0. 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.
|
||||
*/
|
||||
b_0[0] = 0x1;
|
||||
|
||||
/* First block, b_0 */
|
||||
b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
|
||||
/* Nonce: Nonce Flags | A2 | PN
|
||||
* Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
|
||||
*/
|
||||
b_0[1] = qos_tid | (mgmt << 4);
|
||||
memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
|
||||
memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
|
||||
/* l(m) */
|
||||
put_unaligned_be16(data_len, &b_0[14]);
|
||||
|
||||
/* AAD (extra authenticate-only data) / masked 802.11 header
|
||||
* FC | A1 | A2 | A3 | SC | [A4] | [QC] */
|
||||
|
|
@ -407,7 +402,8 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
|
|||
u8 *pos;
|
||||
u8 pn[6];
|
||||
u64 pn64;
|
||||
u8 scratch[6 * AES_BLOCK_SIZE];
|
||||
u8 aad[2 * AES_BLOCK_SIZE];
|
||||
u8 b_0[AES_BLOCK_SIZE];
|
||||
|
||||
if (info->control.hw_key &&
|
||||
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
|
||||
|
|
@ -460,9 +456,9 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
|
|||
return 0;
|
||||
|
||||
pos += IEEE80211_CCMP_HDR_LEN;
|
||||
ccmp_special_blocks(skb, pn, scratch, 0);
|
||||
ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len,
|
||||
pos, skb_put(skb, IEEE80211_CCMP_MIC_LEN));
|
||||
ccmp_special_blocks(skb, pn, b_0, aad, 0);
|
||||
ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
|
||||
skb_put(skb, IEEE80211_CCMP_MIC_LEN));
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -525,16 +521,16 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
|
|||
}
|
||||
|
||||
if (!(status->flag & RX_FLAG_DECRYPTED)) {
|
||||
u8 scratch[6 * AES_BLOCK_SIZE];
|
||||
u8 aad[2 * AES_BLOCK_SIZE];
|
||||
u8 b_0[AES_BLOCK_SIZE];
|
||||
/* hardware didn't decrypt/verify MIC */
|
||||
ccmp_special_blocks(skb, pn, scratch, 1);
|
||||
ccmp_special_blocks(skb, pn, b_0, aad, 1);
|
||||
|
||||
if (ieee80211_aes_ccm_decrypt(
|
||||
key->u.ccmp.tfm, scratch,
|
||||
key->u.ccmp.tfm, b_0, aad,
|
||||
skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
|
||||
data_len,
|
||||
skb->data + skb->len - IEEE80211_CCMP_MIC_LEN,
|
||||
skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN))
|
||||
skb->data + skb->len - IEEE80211_CCMP_MIC_LEN))
|
||||
return RX_DROP_UNUSABLE;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue