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>

diff --git a/crypto/Kconfig b/crypto/Kconfig
index df6f0be66574a770e97ea2693211e4a5d4fa7379..80ea118600ab8a93d1fbe4e78f08c0a78703eadf 100644 (file)
--- 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 3aa4a715c216935bc193d638f341d2d78191bc78..426deb437f197f1748393e959d98876aed439a51 100644 (file)
--- 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 d0067fca0cd012bbf9609daf9992d1be15d40caa..0a64a977f9b328b5744a23b2e8501499ed917a3f 100644 (file)
--- 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