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Commit 19fa7752 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: algif_aead - Switch to new AEAD interface 



This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Note that the user-space interface now requires both input and
output to be of the same length, and both must include space for
the AD as well as the authentication tag.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a3f2185a

crypto/algif_aead.c

+8 −58
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ static inline bool aead_sufficient_data(struct aead_ctx *ctx) 
{

	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));



	return (ctx->used >= (ctx->aead_assoclen + (ctx->enc ? 0 : as)));

	return ctx->used >= ctx->aead_assoclen + as;

}



static void aead_put_sgl(struct sock *sk)
@@ -353,12 +353,8 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, 
	struct sock *sk = sock->sk;

	struct alg_sock *ask = alg_sk(sk);

	struct aead_ctx *ctx = ask->private;

	unsigned bs = crypto_aead_blocksize(crypto_aead_reqtfm(&ctx->aead_req));

	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));

	struct aead_sg_list *sgl = &ctx->tsgl;

	struct scatterlist *sg = NULL;

	struct scatterlist assoc[ALG_MAX_PAGES];

	size_t assoclen = 0;

	unsigned int i = 0;

	int err = -EINVAL;

	unsigned long used = 0;
@@ -407,23 +403,13 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, 
	if (!aead_sufficient_data(ctx))

		goto unlock;



	outlen = used;



	/*

	 * The cipher operation input data is reduced by the associated data

	 * length as this data is processed separately later on.

	 */

	used -= ctx->aead_assoclen;



	if (ctx->enc) {

		/* round up output buffer to multiple of block size */

		outlen = ((used + bs - 1) / bs * bs);

		/* add the size needed for the auth tag to be created */

		outlen += as;

	} else {

		/* output data size is input without the authentication tag */

		outlen = used - as;

		/* round up output buffer to multiple of block size */

		outlen = ((outlen + bs - 1) / bs * bs);

	}

	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);



	/* convert iovecs of output buffers into scatterlists */

	while (iov_iter_count(&msg->msg_iter)) {
@@ -452,47 +438,11 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, 
	if (usedpages < outlen)

		goto unlock;



	sg_init_table(assoc, ALG_MAX_PAGES);

	assoclen = ctx->aead_assoclen;

	/*

	 * Split scatterlist into two: first part becomes AD, second part

	 * is plaintext / ciphertext. The first part is assigned to assoc

	 * scatterlist. When this loop finishes, sg points to the start of the

	 * plaintext / ciphertext.

	 */

	for (i = 0; i < ctx->tsgl.cur; i++) {

		sg = sgl->sg + i;

		if (sg->length <= assoclen) {

			/* AD is larger than one page */

			sg_set_page(assoc + i, sg_page(sg),

				    sg->length, sg->offset);

			assoclen -= sg->length;

			if (i >= ctx->tsgl.cur)

				goto unlock;

		} else if (!assoclen) {

			/* current page is to start of plaintext / ciphertext */

			if (i)

				/* AD terminates at page boundary */

				sg_mark_end(assoc + i - 1);

			else

				/* AD size is zero */

				sg_mark_end(assoc);

			break;

		} else {

			/* AD does not terminate at page boundary */

			sg_set_page(assoc + i, sg_page(sg),

				    assoclen, sg->offset);

			sg_mark_end(assoc + i);

			/* plaintext / ciphertext starts after AD */

			sg->length -= assoclen;

			sg->offset += assoclen;

			break;

		}

	}

	sg_mark_end(sgl->sg + sgl->cur - 1);



	aead_request_set_assoc(&ctx->aead_req, assoc, ctx->aead_assoclen);

	aead_request_set_crypt(&ctx->aead_req, sg, ctx->rsgl[0].sg, used,

			       ctx->iv);

	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->rsgl[0].sg,

			       used, ctx->iv);

	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);



	err = af_alg_wait_for_completion(ctx->enc ?

					 crypto_aead_encrypt(&ctx->aead_req) :