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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2019-07-02 21:41:33 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2019-07-26 14:56:06 +1000
commit5bb12d7825adf0e80b849a273834f3131a6cc4e1 (patch)
tree588cb7e5183d7e194a94c944736f721bc425634c /crypto
parentc184472902d87189082e5a349051197e252ae9af (diff)
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: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/Kconfig1
-rw-r--r--crypto/aes_generic.c153
2 files changed, 3 insertions, 151 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig
index df6f0be66574..80ea118600ab 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -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.
diff --git a/crypto/aes_generic.c b/crypto/aes_generic.c
index 3aa4a715c216..426deb437f19 100644
--- a/crypto/aes_generic.c
+++ b/crypto/aes_generic.c
@@ -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;

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