package/kernel/mac80211/patches/131-Revert-mac80211-aes-cmac-switch-to-shash-CMAC-driver.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sat, 7 Oct 2017 09:37:28 +0200
   3 Subject: [PATCH] Revert "mac80211: aes-cmac: switch to shash CMAC
   4  driver"
   5
   6 This reverts commit 26717828b75dd5c46e97f7f4a9b937d038bb2852.
   7 Reduces mac80211 dependencies for LEDE
   8
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11
  12 --- a/net/mac80211/aes_cmac.c
  13 +++ b/net/mac80211/aes_cmac.c
  14 @@ -22,50 +22,126 @@
  15  #define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */
  16  #define AAD_LEN 20
  17
  18 -static const u8 zero[CMAC_TLEN_256];
  19
  20 -void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
  21 -                       const u8 *data, size_t data_len, u8 *mic)
  22 +void gf_mulx(u8 *pad)
  23 +{
  24 +       int i, carry;
  25 +
  26 +       carry = pad[0] & 0x80;
  27 +       for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
  28 +               pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
  29 +       pad[AES_BLOCK_SIZE - 1] <<= 1;
  30 +       if (carry)
  31 +               pad[AES_BLOCK_SIZE - 1] ^= 0x87;
  32 +}
  33 +
  34 +void aes_cmac_vector(struct crypto_cipher *tfm, size_t num_elem,
  35 +                    const u8 *addr[], const size_t *len, u8 *mac,
  36 +                    size_t mac_len)
  37  {
  38 -       SHASH_DESC_ON_STACK(desc, tfm);
  39 -       u8 out[AES_BLOCK_SIZE];
  40 +       u8 cbc[AES_BLOCK_SIZE], pad[AES_BLOCK_SIZE];
  41 +       const u8 *pos, *end;
  42 +       size_t i, e, left, total_len;
  43 +
  44 +       memset(cbc, 0, AES_BLOCK_SIZE);
  45 +
  46 +       total_len = 0;
  47 +       for (e = 0; e < num_elem; e++)
  48 +               total_len += len[e];
  49 +       left = total_len;
  50 +
  51 +       e = 0;
  52 +       pos = addr[0];
  53 +       end = pos + len[0];
  54 +
  55 +       while (left >= AES_BLOCK_SIZE) {
  56 +               for (i = 0; i < AES_BLOCK_SIZE; i++) {
  57 +                       cbc[i] ^= *pos++;
  58 +                       if (pos >= end) {
  59 +                               e++;
  60 +                               pos = addr[e];
  61 +                               end = pos + len[e];
  62 +                       }
  63 +               }
  64 +               if (left > AES_BLOCK_SIZE)
  65 +                       crypto_cipher_encrypt_one(tfm, cbc, cbc);
  66 +               left -= AES_BLOCK_SIZE;
  67 +       }
  68 +
  69 +       memset(pad, 0, AES_BLOCK_SIZE);
  70 +       crypto_cipher_encrypt_one(tfm, pad, pad);
  71 +       gf_mulx(pad);
  72 +
  73 +       if (left || total_len == 0) {
  74 +               for (i = 0; i < left; i++) {
  75 +                       cbc[i] ^= *pos++;
  76 +                       if (pos >= end) {
  77 +                               e++;
  78 +                               pos = addr[e];
  79 +                               end = pos + len[e];
  80 +                       }
  81 +               }
  82 +               cbc[left] ^= 0x80;
  83 +               gf_mulx(pad);
  84 +       }
  85 +
  86 +       for (i = 0; i < AES_BLOCK_SIZE; i++)
  87 +               pad[i] ^= cbc[i];
  88 +       crypto_cipher_encrypt_one(tfm, pad, pad);
  89 +       memcpy(mac, pad, mac_len);
  90 +}
  91
  92 -       desc->tfm = tfm;
  93
  94 -       crypto_shash_init(desc);
  95 -       crypto_shash_update(desc, aad, AAD_LEN);
  96 -       crypto_shash_update(desc, data, data_len - CMAC_TLEN);
  97 -       crypto_shash_finup(desc, zero, CMAC_TLEN, out);
  98 +void ieee80211_aes_cmac(struct crypto_cipher *tfm, const u8 *aad,
  99 +                       const u8 *data, size_t data_len, u8 *mic)
 100 +{
 101 +       const u8 *addr[3];
 102 +       size_t len[3];
 103 +       u8 zero[CMAC_TLEN];
 104 +
 105 +       memset(zero, 0, CMAC_TLEN);
 106 +       addr[0] = aad;
 107 +       len[0] = AAD_LEN;
 108 +       addr[1] = data;
 109 +       len[1] = data_len - CMAC_TLEN;
 110 +       addr[2] = zero;
 111 +       len[2] = CMAC_TLEN;
 112
 113 -       memcpy(mic, out, CMAC_TLEN);
 114 +       aes_cmac_vector(tfm, 3, addr, len, mic, CMAC_TLEN);
 115  }
 116
 117 -void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
 118 +void ieee80211_aes_cmac_256(struct crypto_cipher *tfm, const u8 *aad,
 119                             const u8 *data, size_t data_len, u8 *mic)
 120  {
 121 -       SHASH_DESC_ON_STACK(desc, tfm);
 122 +       const u8 *addr[3];
 123 +       size_t len[3];
 124 +       u8 zero[CMAC_TLEN_256];
 125 +
 126 +       memset(zero, 0, CMAC_TLEN_256);
 127 +       addr[0] = aad;
 128 +       len[0] = AAD_LEN;
 129 +       addr[1] = data;
 130 +       len[1] = data_len - CMAC_TLEN_256;
 131 +       addr[2] = zero;
 132 +       len[2] = CMAC_TLEN_256;
 133
 134 -       desc->tfm = tfm;
 135 -
 136 -       crypto_shash_init(desc);
 137 -       crypto_shash_update(desc, aad, AAD_LEN);
 138 -       crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
 139 -       crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
 140 +       aes_cmac_vector(tfm, 3, addr, len, mic, CMAC_TLEN_256);
 141  }
 142
 143 -struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
 144 -                                                 size_t key_len)
 145 +struct crypto_cipher *ieee80211_aes_cmac_key_setup(const u8 key[],
 146 +                                                  size_t key_len)
 147  {
 148 -       struct crypto_shash *tfm;
 149 +       struct crypto_cipher *tfm;
 150
 151 -       tfm = crypto_alloc_shash("cmac(aes)", 0, 0);
 152 +       tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
 153         if (!IS_ERR(tfm))
 154 -               crypto_shash_setkey(tfm, key, key_len);
 155 +               crypto_cipher_setkey(tfm, key, key_len);
 156
 157         return tfm;
 158  }
 159
 160 -void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm)
 161 +
 162 +void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm)
 163  {
 164 -       crypto_free_shash(tfm);
 165 +       crypto_free_cipher(tfm);
 166  }
 167 --- a/net/mac80211/aes_cmac.h
 168 +++ b/net/mac80211/aes_cmac.h
 169 @@ -10,14 +10,13 @@
 170  #define AES_CMAC_H
 171
 172  #include <linux/crypto.h>
 173 -#include <crypto/hash.h>
 174
 175 -struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
 176 -                                                 size_t key_len);
 177 -void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
 178 +struct crypto_cipher *ieee80211_aes_cmac_key_setup(const u8 key[],
 179 +                                                  size_t key_len);
 180 +void ieee80211_aes_cmac(struct crypto_cipher *tfm, const u8 *aad,
 181                         const u8 *data, size_t data_len, u8 *mic);
 182 -void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
 183 +void ieee80211_aes_cmac_256(struct crypto_cipher *tfm, const u8 *aad,
 184                             const u8 *data, size_t data_len, u8 *mic);
 185 -void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm);
 186 +void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm);
 187
 188  #endif /* AES_CMAC_H */
 189 --- a/net/mac80211/key.h
 190 +++ b/net/mac80211/key.h
 191 @@ -93,7 +93,7 @@ struct ieee80211_key {
 192                 } ccmp;
 193                 struct {
 194                         u8 rx_pn[IEEE80211_CMAC_PN_LEN];
 195 -                       struct crypto_shash *tfm;
 196 +                       struct crypto_cipher *tfm;
 197                         u32 replays; /* dot11RSNAStatsCMACReplays */
 198                         u32 icverrors; /* dot11RSNAStatsCMACICVErrors */
 199                 } aes_cmac;