Commit 5bb12d78 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu

crypto: aes-generic - drop key expansion routine in favor of library version

Drop aes-generic's version of crypto_aes_expand_key(), and switch to
the key expansion routine provided by the AES library. AES key expansion
is not performance critical, and it is better to have a single version
shared by all AES implementations.
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent c1844729
......@@ -1072,6 +1072,7 @@ config CRYPTO_LIB_AES
config CRYPTO_AES
tristate "AES cipher algorithms"
select CRYPTO_ALGAPI
select CRYPTO_LIB_AES
help
AES cipher algorithms (FIPS-197). AES uses the Rijndael
algorithm.
......
......@@ -1125,155 +1125,6 @@ EXPORT_SYMBOL_GPL(crypto_fl_tab);
EXPORT_SYMBOL_GPL(crypto_it_tab);
EXPORT_SYMBOL_GPL(crypto_il_tab);
/* initialise the key schedule from the user supplied key */
#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
#define imix_col(y, x) do { \
u = star_x(x); \
v = star_x(u); \
w = star_x(v); \
t = w ^ (x); \
(y) = u ^ v ^ w; \
(y) ^= ror32(u ^ t, 8) ^ \
ror32(v ^ t, 16) ^ \
ror32(t, 24); \
} while (0)
#define ls_box(x) \
crypto_fl_tab[0][byte(x, 0)] ^ \
crypto_fl_tab[1][byte(x, 1)] ^ \
crypto_fl_tab[2][byte(x, 2)] ^ \
crypto_fl_tab[3][byte(x, 3)]
#define loop4(i) do { \
t = ror32(t, 8); \
t = ls_box(t) ^ rco_tab[i]; \
t ^= ctx->key_enc[4 * i]; \
ctx->key_enc[4 * i + 4] = t; \
t ^= ctx->key_enc[4 * i + 1]; \
ctx->key_enc[4 * i + 5] = t; \
t ^= ctx->key_enc[4 * i + 2]; \
ctx->key_enc[4 * i + 6] = t; \
t ^= ctx->key_enc[4 * i + 3]; \
ctx->key_enc[4 * i + 7] = t; \
} while (0)
#define loop6(i) do { \
t = ror32(t, 8); \
t = ls_box(t) ^ rco_tab[i]; \
t ^= ctx->key_enc[6 * i]; \
ctx->key_enc[6 * i + 6] = t; \
t ^= ctx->key_enc[6 * i + 1]; \
ctx->key_enc[6 * i + 7] = t; \
t ^= ctx->key_enc[6 * i + 2]; \
ctx->key_enc[6 * i + 8] = t; \
t ^= ctx->key_enc[6 * i + 3]; \
ctx->key_enc[6 * i + 9] = t; \
t ^= ctx->key_enc[6 * i + 4]; \
ctx->key_enc[6 * i + 10] = t; \
t ^= ctx->key_enc[6 * i + 5]; \
ctx->key_enc[6 * i + 11] = t; \
} while (0)
#define loop8tophalf(i) do { \
t = ror32(t, 8); \
t = ls_box(t) ^ rco_tab[i]; \
t ^= ctx->key_enc[8 * i]; \
ctx->key_enc[8 * i + 8] = t; \
t ^= ctx->key_enc[8 * i + 1]; \
ctx->key_enc[8 * i + 9] = t; \
t ^= ctx->key_enc[8 * i + 2]; \
ctx->key_enc[8 * i + 10] = t; \
t ^= ctx->key_enc[8 * i + 3]; \
ctx->key_enc[8 * i + 11] = t; \
} while (0)
#define loop8(i) do { \
loop8tophalf(i); \
t = ctx->key_enc[8 * i + 4] ^ ls_box(t); \
ctx->key_enc[8 * i + 12] = t; \
t ^= ctx->key_enc[8 * i + 5]; \
ctx->key_enc[8 * i + 13] = t; \
t ^= ctx->key_enc[8 * i + 6]; \
ctx->key_enc[8 * i + 14] = t; \
t ^= ctx->key_enc[8 * i + 7]; \
ctx->key_enc[8 * i + 15] = t; \
} while (0)
/**
* crypto_aes_expand_key - Expands the AES key as described in FIPS-197
* @ctx: The location where the computed key will be stored.
* @in_key: The supplied key.
* @key_len: The length of the supplied key.
*
* Returns 0 on success. The function fails only if an invalid key size (or
* pointer) is supplied.
* The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes
* key schedule plus a 16 bytes key which is used before the first round).
* The decryption key is prepared for the "Equivalent Inverse Cipher" as
* described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is
* for the initial combination, the second slot for the first round and so on.
*/
int crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key,
unsigned int key_len)
{
u32 i, t, u, v, w, j;
if (key_len != AES_KEYSIZE_128 && key_len != AES_KEYSIZE_192 &&
key_len != AES_KEYSIZE_256)
return -EINVAL;
ctx->key_length = key_len;
ctx->key_enc[0] = get_unaligned_le32(in_key);
ctx->key_enc[1] = get_unaligned_le32(in_key + 4);
ctx->key_enc[2] = get_unaligned_le32(in_key + 8);
ctx->key_enc[3] = get_unaligned_le32(in_key + 12);
ctx->key_dec[key_len + 24] = ctx->key_enc[0];
ctx->key_dec[key_len + 25] = ctx->key_enc[1];
ctx->key_dec[key_len + 26] = ctx->key_enc[2];
ctx->key_dec[key_len + 27] = ctx->key_enc[3];
switch (key_len) {
case AES_KEYSIZE_128:
t = ctx->key_enc[3];
for (i = 0; i < 10; ++i)
loop4(i);
break;
case AES_KEYSIZE_192:
ctx->key_enc[4] = get_unaligned_le32(in_key + 16);
t = ctx->key_enc[5] = get_unaligned_le32(in_key + 20);
for (i = 0; i < 8; ++i)
loop6(i);
break;
case AES_KEYSIZE_256:
ctx->key_enc[4] = get_unaligned_le32(in_key + 16);
ctx->key_enc[5] = get_unaligned_le32(in_key + 20);
ctx->key_enc[6] = get_unaligned_le32(in_key + 24);
t = ctx->key_enc[7] = get_unaligned_le32(in_key + 28);
for (i = 0; i < 6; ++i)
loop8(i);
loop8tophalf(i);
break;
}
ctx->key_dec[0] = ctx->key_enc[key_len + 24];
ctx->key_dec[1] = ctx->key_enc[key_len + 25];
ctx->key_dec[2] = ctx->key_enc[key_len + 26];
ctx->key_dec[3] = ctx->key_enc[key_len + 27];
for (i = 4; i < key_len + 24; ++i) {
j = key_len + 24 - (i & ~3) + (i & 3);
imix_col(ctx->key_dec[j], ctx->key_enc[i]);
}
return 0;
}
EXPORT_SYMBOL_GPL(crypto_aes_expand_key);
/**
* crypto_aes_set_key - Set the AES key.
* @tfm: The %crypto_tfm that is used in the context.
......@@ -1281,7 +1132,7 @@ EXPORT_SYMBOL_GPL(crypto_aes_expand_key);
* @key_len: The size of the key.
*
* Returns 0 on success, on failure the %CRYPTO_TFM_RES_BAD_KEY_LEN flag in tfm
* is set. The function uses crypto_aes_expand_key() to expand the key.
* is set. The function uses aes_expand_key() to expand the key.
* &crypto_aes_ctx _must_ be the private data embedded in @tfm which is
* retrieved with crypto_tfm_ctx().
*/
......@@ -1292,7 +1143,7 @@ int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
u32 *flags = &tfm->crt_flags;
int ret;
ret = crypto_aes_expand_key(ctx, in_key, key_len);
ret = aes_expandkey(ctx, in_key, key_len);
if (!ret)
return 0;
......
......@@ -35,8 +35,6 @@ extern const u32 crypto_il_tab[4][256] ____cacheline_aligned;
int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len);
int crypto_aes_expand_key(struct crypto_aes_ctx *ctx, const u8 *in_key,
unsigned int key_len);
/**
* aes_expandkey - Expands the AES key as described in FIPS-197
......
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