crypto: arm64/aes-ce-cipher - use AES library as fallback

Instead of calling into the table based scalar AES code in situations
where the SIMD unit may not be used, use the generic AES code, which
is more appropriate since it is less likely to be susceptible to
timing attacks.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

arch/arm64/crypto/Kconfig

@@ -73,7 +73,7 @@ config CRYPTO_AES_ARM64_CE
 	tristate "AES core cipher using ARMv8 Crypto Extensions"
 	depends on ARM64 && KERNEL_MODE_NEON
 	select CRYPTO_ALGAPI
-	select CRYPTO_AES_ARM64
+	select CRYPTO_LIB_AES
 
 config CRYPTO_AES_ARM64_CE_CCM
 	tristate "AES in CCM mode using ARMv8 Crypto Extensions"

arch/arm64/crypto/aes-ce-glue.c

@@ -20,9 +20,6 @@ MODULE_DESCRIPTION("Synchronous AES cipher using ARMv8 Crypto Extensions");
 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_LICENSE("GPL v2");
 
-asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
-asmlinkage void __aes_arm64_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
-
 struct aes_block {
 	u8 b[AES_BLOCK_SIZE];
 };
@@ -51,7 +48,7 @@ static void aes_cipher_encrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
 	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
 
 	if (!crypto_simd_usable()) {
-		__aes_arm64_encrypt(ctx->key_enc, dst, src, num_rounds(ctx));
+		aes_encrypt(ctx, dst, src);
 		return;
 	}
 
@@ -65,7 +62,7 @@ static void aes_cipher_decrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
 	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
 
 	if (!crypto_simd_usable()) {
-		__aes_arm64_decrypt(ctx->key_dec, dst, src, num_rounds(ctx));
+		aes_decrypt(ctx, dst, src);
 		return;
 	}
 

arch/arm64/crypto/aes-cipher-glue.c

@@ -10,10 +10,7 @@
 #include <linux/module.h>
 
 asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
-EXPORT_SYMBOL(__aes_arm64_encrypt);
-
 asmlinkage void __aes_arm64_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds);
-EXPORT_SYMBOL(__aes_arm64_decrypt);
 
 static void aes_arm64_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 {