From 5bb12d7825adf0e80b849a273834f3131a6cc4e1 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 2 Jul 2019 21:41:33 +0200 Subject: [PATCH] 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 Signed-off-by: Herbert Xu --- crypto/Kconfig | 1 + crypto/aes_generic.c | 153 +------------------------------------------ include/crypto/aes.h | 2 - 3 files changed, 3 insertions(+), 153 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; diff --git a/include/crypto/aes.h b/include/crypto/aes.h index d0067fca0cd0..0a64a977f9b3 100644 --- a/include/crypto/aes.h +++ b/include/crypto/aes.h @@ -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 -- 2.30.2