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From: Felix Fietkau <nbd@nbd.name>
Date: Sat, 7 Oct 2017 09:37:28 +0200
Subject: [PATCH] Revert "mac80211: aes-cmac: switch to shash CMAC
driver"
This reverts commit 26717828b75dd5c46e97f7f4a9b937d038bb2852.
Reduces mac80211 dependencies for LEDE
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -19,50 +19,126 @@
#define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */
#define AAD_LEN 20
-static const u8 zero[CMAC_TLEN_256];
-void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
- const u8 *data, size_t data_len, u8 *mic)
+void gf_mulx(u8 *pad)
+{
+ int i, carry;
+
+ carry = pad[0] & 0x80;
+ for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
+ pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
+ pad[AES_BLOCK_SIZE - 1] <<= 1;
+ if (carry)
+ pad[AES_BLOCK_SIZE - 1] ^= 0x87;
+}
+
+void aes_cmac_vector(struct crypto_cipher *tfm, size_t num_elem,
+ const u8 *addr[], const size_t *len, u8 *mac,
+ size_t mac_len)
{
- SHASH_DESC_ON_STACK(desc, tfm);
- u8 out[AES_BLOCK_SIZE];
+ u8 cbc[AES_BLOCK_SIZE], pad[AES_BLOCK_SIZE];
+ const u8 *pos, *end;
+ size_t i, e, left, total_len;
+
+ memset(cbc, 0, AES_BLOCK_SIZE);
+
+ total_len = 0;
+ for (e = 0; e < num_elem; e++)
+ total_len += len[e];
+ left = total_len;
+
+ e = 0;
+ pos = addr[0];
+ end = pos + len[0];
+
+ while (left >= AES_BLOCK_SIZE) {
+ for (i = 0; i < AES_BLOCK_SIZE; i++) {
+ cbc[i] ^= *pos++;
+ if (pos >= end) {
+ e++;
+ pos = addr[e];
+ end = pos + len[e];
+ }
+ }
+ if (left > AES_BLOCK_SIZE)
+ crypto_cipher_encrypt_one(tfm, cbc, cbc);
+ left -= AES_BLOCK_SIZE;
+ }
+
+ memset(pad, 0, AES_BLOCK_SIZE);
+ crypto_cipher_encrypt_one(tfm, pad, pad);
+ gf_mulx(pad);
+
+ if (left || total_len == 0) {
+ for (i = 0; i < left; i++) {
+ cbc[i] ^= *pos++;
+ if (pos >= end) {
+ e++;
+ pos = addr[e];
+ end = pos + len[e];
+ }
+ }
+ cbc[left] ^= 0x80;
+ gf_mulx(pad);
+ }
+
+ for (i = 0; i < AES_BLOCK_SIZE; i++)
+ pad[i] ^= cbc[i];
+ crypto_cipher_encrypt_one(tfm, pad, pad);
+ memcpy(mac, pad, mac_len);
+}
- desc->tfm = tfm;
- crypto_shash_init(desc);
- crypto_shash_update(desc, aad, AAD_LEN);
- crypto_shash_update(desc, data, data_len - CMAC_TLEN);
- crypto_shash_finup(desc, zero, CMAC_TLEN, out);
+void ieee80211_aes_cmac(struct crypto_cipher *tfm, const u8 *aad,
+ const u8 *data, size_t data_len, u8 *mic)
+{
+ const u8 *addr[3];
+ size_t len[3];
+ u8 zero[CMAC_TLEN];
+
+ memset(zero, 0, CMAC_TLEN);
+ addr[0] = aad;
+ len[0] = AAD_LEN;
+ addr[1] = data;
+ len[1] = data_len - CMAC_TLEN;
+ addr[2] = zero;
+ len[2] = CMAC_TLEN;
- memcpy(mic, out, CMAC_TLEN);
+ aes_cmac_vector(tfm, 3, addr, len, mic, CMAC_TLEN);
}
-void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
+void ieee80211_aes_cmac_256(struct crypto_cipher *tfm, const u8 *aad,
const u8 *data, size_t data_len, u8 *mic)
{
- SHASH_DESC_ON_STACK(desc, tfm);
+ const u8 *addr[3];
+ size_t len[3];
+ u8 zero[CMAC_TLEN_256];
+
+ memset(zero, 0, CMAC_TLEN_256);
+ addr[0] = aad;
+ len[0] = AAD_LEN;
+ addr[1] = data;
+ len[1] = data_len - CMAC_TLEN_256;
+ addr[2] = zero;
+ len[2] = CMAC_TLEN_256;
- desc->tfm = tfm;
-
- crypto_shash_init(desc);
- crypto_shash_update(desc, aad, AAD_LEN);
- crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
- crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
+ aes_cmac_vector(tfm, 3, addr, len, mic, CMAC_TLEN_256);
}
-struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
- size_t key_len)
+struct crypto_cipher *ieee80211_aes_cmac_key_setup(const u8 key[],
+ size_t key_len)
{
- struct crypto_shash *tfm;
+ struct crypto_cipher *tfm;
- tfm = crypto_alloc_shash("cmac(aes)", 0, 0);
+ tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
if (!IS_ERR(tfm))
- crypto_shash_setkey(tfm, key, key_len);
+ crypto_cipher_setkey(tfm, key, key_len);
return tfm;
}
-void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm)
+
+void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm)
{
- crypto_free_shash(tfm);
+ crypto_free_cipher(tfm);
}
--- a/net/mac80211/aes_cmac.h
+++ b/net/mac80211/aes_cmac.h
@@ -7,14 +7,13 @@
#define AES_CMAC_H
#include <linux/crypto.h>
-#include <crypto/hash.h>
-struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
- size_t key_len);
-void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
+struct crypto_cipher *ieee80211_aes_cmac_key_setup(const u8 key[],
+ size_t key_len);
+void ieee80211_aes_cmac(struct crypto_cipher *tfm, const u8 *aad,
const u8 *data, size_t data_len, u8 *mic);
-void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
+void ieee80211_aes_cmac_256(struct crypto_cipher *tfm, const u8 *aad,
const u8 *data, size_t data_len, u8 *mic);
-void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm);
+void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm);
#endif /* AES_CMAC_H */
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -92,7 +92,7 @@ struct ieee80211_key {
} ccmp;
struct {
u8 rx_pn[IEEE80211_CMAC_PN_LEN];
- struct crypto_shash *tfm;
+ struct crypto_cipher *tfm;
u32 replays; /* dot11RSNAStatsCMACReplays */
u32 icverrors; /* dot11RSNAStatsCMACICVErrors */
} aes_cmac;
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