[PATCH 23/36] crypto: arm/ghash - Use new AES library API

[Eric Biggers <ebiggers@kernel.org>]

Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note: aes_encrypt_new() will be renamed to aes_encrypt() once all
callers of the old aes_encrypt() have been updated.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 arch/arm/crypto/ghash-ce-glue.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm/crypto/ghash-ce-glue.c b/arch/arm/crypto/ghash-ce-glue.c
index a52dcc8c1e33..9ab03bce352d 100644
--- a/arch/arm/crypto/ghash-ce-glue.c
+++ b/arch/arm/crypto/ghash-ce-glue.c
@@ -202,24 +202,28 @@ int pmull_gcm_dec_final(int bytes, u64 dg[], char *tag,
 
 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *inkey,
 			  unsigned int keylen)
 {
 	struct gcm_key *ctx = crypto_aead_ctx(tfm);
-	struct crypto_aes_ctx aes_ctx;
+	struct aes_enckey aes_key;
 	be128 h, k;
 	int ret;
 
-	ret = aes_expandkey(&aes_ctx, inkey, keylen);
+	ret = aes_prepareenckey(&aes_key, inkey, keylen);
 	if (ret)
 		return -EINVAL;
 
-	aes_encrypt(&aes_ctx, (u8 *)&k, (u8[AES_BLOCK_SIZE]){});
+	aes_encrypt_new(&aes_key, (u8 *)&k, (u8[AES_BLOCK_SIZE]){});
 
-	memcpy(ctx->rk, aes_ctx.key_enc, sizeof(ctx->rk));
+	/*
+	 * Note: this assumes that the arm implementation of the AES library
+	 * stores the standard round keys in k.rndkeys.
+	 */
+	memcpy(ctx->rk, aes_key.k.rndkeys, sizeof(ctx->rk));
 	ctx->rounds = 6 + keylen / 4;
 
-	memzero_explicit(&aes_ctx, sizeof(aes_ctx));
+	memzero_explicit(&aes_key, sizeof(aes_key));
 
 	ghash_reflect(ctx->h[0], &k);
 
 	h = k;
 	gf128mul_lle(&h, &k);
-- 
2.52.0