Commit 91308019 authored by Romain Izard's avatar Romain Izard Committed by Herbert Xu
Browse files

crypto: atmel-aes - properly set IV after {en,de}crypt 



Certain cipher modes like CTS expect the IV (req->info) of
ablkcipher_request (or equivalently req->iv of skcipher_request) to
contain the last ciphertext block when the {en,de}crypt operation is done.

Fix this issue for the Atmel AES hardware engine. The tcrypt test
case for cts(cbc(aes)) is now correctly passed.

In the case of in-place decryption, copy the ciphertext in an
intermediate buffer before decryption.

Signed-off-by: default avatarRomain Izard <romain.izard.pro@gmail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 142a27f0

drivers/crypto/atmel-aes.c

+37 −3
Original line number Diff line number Diff line
@@ -111,6 +111,7 @@ struct atmel_aes_base_ctx { 
	int			keylen;

	u32			key[AES_KEYSIZE_256 / sizeof(u32)];

	u16			block_size;

	bool			is_aead;

};



struct atmel_aes_ctx {
@@ -157,6 +158,7 @@ struct atmel_aes_authenc_ctx { 


struct atmel_aes_reqctx {

	unsigned long		mode;

	u32			lastc[AES_BLOCK_SIZE / sizeof(u32)];

};



#ifdef CONFIG_CRYPTO_DEV_ATMEL_AUTHENC
@@ -498,12 +500,34 @@ static void atmel_aes_authenc_complete(struct atmel_aes_dev *dd, int err); 
static inline int atmel_aes_complete(struct atmel_aes_dev *dd, int err)

{

#ifdef CONFIG_CRYPTO_DEV_ATMEL_AUTHENC

	if (dd->ctx->is_aead)

		atmel_aes_authenc_complete(dd, err);

#endif



	clk_disable(dd->iclk);

	dd->flags &= ~AES_FLAGS_BUSY;



	if (!dd->ctx->is_aead) {

		struct ablkcipher_request *req =

			ablkcipher_request_cast(dd->areq);

		struct atmel_aes_reqctx *rctx = ablkcipher_request_ctx(req);

		struct crypto_ablkcipher *ablkcipher =

			crypto_ablkcipher_reqtfm(req);

		int ivsize = crypto_ablkcipher_ivsize(ablkcipher);



		if (rctx->mode & AES_FLAGS_ENCRYPT) {

			scatterwalk_map_and_copy(req->info, req->dst,

				req->nbytes - ivsize, ivsize, 0);

		} else {

			if (req->src == req->dst) {

				memcpy(req->info, rctx->lastc, ivsize);

			} else {

				scatterwalk_map_and_copy(req->info, req->src,

					req->nbytes - ivsize, ivsize, 0);

			}

		}

	}



	if (dd->is_async)

		dd->areq->complete(dd->areq, err);
@@ -1072,11 +1096,11 @@ static int atmel_aes_ctr_start(struct atmel_aes_dev *dd) 


static int atmel_aes_crypt(struct ablkcipher_request *req, unsigned long mode)

{

	struct atmel_aes_base_ctx *ctx;

	struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req);

	struct atmel_aes_base_ctx *ctx = crypto_ablkcipher_ctx(ablkcipher);

	struct atmel_aes_reqctx *rctx;

	struct atmel_aes_dev *dd;



	ctx = crypto_ablkcipher_ctx(crypto_ablkcipher_reqtfm(req));

	switch (mode & AES_FLAGS_OPMODE_MASK) {

	case AES_FLAGS_CFB8:

		ctx->block_size = CFB8_BLOCK_SIZE;
@@ -1098,6 +1122,7 @@ static int atmel_aes_crypt(struct ablkcipher_request *req, unsigned long mode) 
		ctx->block_size = AES_BLOCK_SIZE;

		break;

	}

	ctx->is_aead = false;



	dd = atmel_aes_find_dev(ctx);

	if (!dd)
@@ -1106,6 +1131,13 @@ static int atmel_aes_crypt(struct ablkcipher_request *req, unsigned long mode) 
	rctx = ablkcipher_request_ctx(req);

	rctx->mode = mode;



	if (!(mode & AES_FLAGS_ENCRYPT) && (req->src == req->dst)) {

		int ivsize = crypto_ablkcipher_ivsize(ablkcipher);



		scatterwalk_map_and_copy(rctx->lastc, req->src,

			(req->nbytes - ivsize), ivsize, 0);

	}



	return atmel_aes_handle_queue(dd, &req->base);

}
@@ -1740,6 +1772,7 @@ static int atmel_aes_gcm_crypt(struct aead_request *req, 


	ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));

	ctx->block_size = AES_BLOCK_SIZE;

	ctx->is_aead = true;



	dd = atmel_aes_find_dev(ctx);

	if (!dd)
@@ -2224,6 +2257,7 @@ static int atmel_aes_authenc_crypt(struct aead_request *req, 


	rctx->base.mode = mode;

	ctx->block_size = AES_BLOCK_SIZE;

	ctx->is_aead = true;



	dd = atmel_aes_find_dev(ctx);

	if (!dd)

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