Re: [PATCH 06/10] crypto: omap-aes: gcm: Handle inputs properly

From: Felipe Balbi
Date: Thu Jul 02 2015 - 04:05:27 EST


On Thu, Jul 02, 2015 at 10:48:36AM +0530, Lokesh Vutla wrote:
> Its not necessary that assoc data and plain text is passed always.
> Add these checks before processing the input.
>
> Signed-off-by: Lokesh Vutla <lokeshvutla@xxxxxx>

why can't this be combined with patch which added GCM in the first
place ?

> ---
> drivers/crypto/omap-aes-gcm.c | 26 ++++++++++++++++++++------
> 1 file changed, 20 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/crypto/omap-aes-gcm.c b/drivers/crypto/omap-aes-gcm.c
> index 1be9d91..72815af 100644
> --- a/drivers/crypto/omap-aes-gcm.c
> +++ b/drivers/crypto/omap-aes-gcm.c
> @@ -87,7 +87,7 @@ static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
> struct aead_request *req)
> {
> void *buf_in;
> - int alen, clen;
> + int alen, clen, nsg;
> struct crypto_aead *aead = crypto_aead_reqtfm(req);
> unsigned int authlen = crypto_aead_authsize(aead);
> u32 dec = !(dd->flags & FLAGS_ENCRYPT);
> @@ -97,12 +97,18 @@ static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
>
> dd->sgs_copied = 0;
>
> - sg_init_table(dd->in_sgl, 2);
> - buf_in = sg_virt(req->assoc);
> - sg_set_buf(dd->in_sgl, buf_in, alen);
> + nsg = 1 + !!(req->assoclen && req->cryptlen);
>
> - buf_in = sg_virt(req->src);
> - sg_set_buf(&dd->in_sgl[1], buf_in, clen);
> + sg_init_table(dd->in_sgl, nsg);
> + if (req->assoclen) {
> + buf_in = sg_virt(req->assoc);
> + sg_set_buf(dd->in_sgl, buf_in, alen);
> + }
> +
> + if (req->cryptlen) {
> + buf_in = sg_virt(req->src);
> + sg_set_buf(&dd->in_sgl[nsg - 1], buf_in, clen);
> + }
>
> dd->in_sg = dd->in_sgl;
> dd->total = clen;
> @@ -258,6 +264,8 @@ static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode)
> {
> struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
> struct omap_aes_reqctx *rctx = aead_request_ctx(req);
> + struct crypto_aead *aead = crypto_aead_reqtfm(req);
> + unsigned int authlen = crypto_aead_authsize(aead);
> struct omap_aes_dev *dd;
> __be32 counter = cpu_to_be32(1);
> int err;
> @@ -270,6 +278,12 @@ static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode)
> if (err)
> return err;
>
> + if (req->assoclen + req->cryptlen == 0) {
> + scatterwalk_map_and_copy(ctx->auth_tag, req->dst, 0, authlen,
> + 1);
> + return 0;
> + }
> +
> dd = omap_aes_find_dev(ctx);
> if (!dd)
> return -ENODEV;
> --
> 1.7.9.5
>
> --
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--
balbi

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