Commit 65d0042b authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: arm64/aes-cts-cbc - factor out CBC en/decryption of a walk 



The plain CBC driver and the CTS one share some code that iterates over
a scatterwalk and invokes the CBC asm code to do the processing. The
upcoming ESSIV/CBC mode will clone that pattern for the third time, so
let's factor it out first.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent f975abb2

arch/arm64/crypto/aes-glue.c

+40 −42
Original line number Diff line number Diff line
@@ -186,44 +186,62 @@ static int ecb_decrypt(struct skcipher_request *req) 
	return err;

}



static int cbc_encrypt(struct skcipher_request *req)

static int cbc_encrypt_walk(struct skcipher_request *req,

			    struct skcipher_walk *walk)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

	int err, rounds = 6 + ctx->key_length / 4;

	struct skcipher_walk walk;

	int err = 0, rounds = 6 + ctx->key_length / 4;

	unsigned int blocks;



	err = skcipher_walk_virt(&walk, req, false);



	while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {

	while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) {

		kernel_neon_begin();

		aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,

				ctx->key_enc, rounds, blocks, walk.iv);

		aes_cbc_encrypt(walk->dst.virt.addr, walk->src.virt.addr,

				ctx->key_enc, rounds, blocks, walk->iv);

		kernel_neon_end();

		err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);

		err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE);

	}

	return err;

}



static int cbc_decrypt(struct skcipher_request *req)

static int cbc_encrypt(struct skcipher_request *req)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

	int err, rounds = 6 + ctx->key_length / 4;

	struct skcipher_walk walk;

	unsigned int blocks;

	int err;



	err = skcipher_walk_virt(&walk, req, false);

	if (err)

		return err;

	return cbc_encrypt_walk(req, &walk);

}



	while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {

static int cbc_decrypt_walk(struct skcipher_request *req,

			    struct skcipher_walk *walk)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

	int err = 0, rounds = 6 + ctx->key_length / 4;

	unsigned int blocks;



	while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) {

		kernel_neon_begin();

		aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,

				ctx->key_dec, rounds, blocks, walk.iv);

		aes_cbc_decrypt(walk->dst.virt.addr, walk->src.virt.addr,

				ctx->key_dec, rounds, blocks, walk->iv);

		kernel_neon_end();

		err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);

		err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE);

	}

	return err;

}



static int cbc_decrypt(struct skcipher_request *req)

{

	struct skcipher_walk walk;

	int err;



	err = skcipher_walk_virt(&walk, req, false);

	if (err)

		return err;

	return cbc_decrypt_walk(req, &walk);

}



static int cts_cbc_init_tfm(struct crypto_skcipher *tfm)
@@ -251,22 +269,12 @@ static int cts_cbc_encrypt(struct skcipher_request *req) 
	}



	if (cbc_blocks > 0) {

		unsigned int blocks;



		skcipher_request_set_crypt(&rctx->subreq, req->src, req->dst,

					   cbc_blocks * AES_BLOCK_SIZE,

					   req->iv);



		err = skcipher_walk_virt(&walk, &rctx->subreq, false);



		while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {

			kernel_neon_begin();

			aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,

					ctx->key_enc, rounds, blocks, walk.iv);

			kernel_neon_end();

			err = skcipher_walk_done(&walk,

						 walk.nbytes % AES_BLOCK_SIZE);

		}

		err = skcipher_walk_virt(&walk, &rctx->subreq, false) ?:

		      cbc_encrypt_walk(&rctx->subreq, &walk);

		if (err)

			return err;
@@ -316,22 +324,12 @@ static int cts_cbc_decrypt(struct skcipher_request *req) 
	}



	if (cbc_blocks > 0) {

		unsigned int blocks;



		skcipher_request_set_crypt(&rctx->subreq, req->src, req->dst,

					   cbc_blocks * AES_BLOCK_SIZE,

					   req->iv);



		err = skcipher_walk_virt(&walk, &rctx->subreq, false);



		while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {

			kernel_neon_begin();

			aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,

					ctx->key_dec, rounds, blocks, walk.iv);

			kernel_neon_end();

			err = skcipher_walk_done(&walk,

						 walk.nbytes % AES_BLOCK_SIZE);

		}

		err = skcipher_walk_virt(&walk, &rctx->subreq, false) ?:

		      cbc_decrypt_walk(&rctx->subreq, &walk);

		if (err)

			return err;

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