[PATCH v1 10/15] crypto: talitos - properly handle split ICV.

[Christophe Leroy]

The driver assumes that the ICV is as a single piece in the last
element of the scatterlist. This assumption is wrong.

This patch ensures that the ICV is properly handled regardless of
the scatterlist layout.

Fixes: 9c4a79653b35 ("crypto: talitos - Freescale integrated security engine 
(SEC) driver")
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
 drivers/crypto/talitos.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index e35581d67315..7c8a3a717b91 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -1069,7 +1069,6 @@ static void ipsec_esp_encrypt_done(struct device *dev,
        unsigned int authsize = crypto_aead_authsize(authenc);
        unsigned int ivsize = crypto_aead_ivsize(authenc);
        struct talitos_edesc *edesc;
-       struct scatterlist *sg;
        void *icvdata;
 
        edesc = container_of(desc, struct talitos_edesc, desc);
@@ -1083,9 +1082,8 @@ static void ipsec_esp_encrypt_done(struct device *dev,
                else
                        icvdata = &edesc->link_tbl[edesc->src_nents +
                                                   edesc->dst_nents + 2];
-               sg = sg_last(areq->dst, edesc->dst_nents);
-               memcpy((char *)sg_virt(sg) + sg->length - authsize,
-                      icvdata, authsize);
+               sg_pcopy_from_buffer(areq->dst, edesc->dst_nents ? : 1, icvdata,
+                                    authsize, areq->assoclen + areq->cryptlen);
        }
 
        dma_unmap_single(dev, edesc->iv_dma, ivsize, DMA_TO_DEVICE);
@@ -1103,7 +1101,6 @@ static void ipsec_esp_decrypt_swauth_done(struct device 
*dev,
        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
        unsigned int authsize = crypto_aead_authsize(authenc);
        struct talitos_edesc *edesc;
-       struct scatterlist *sg;
        char *oicv, *icv;
        struct talitos_private *priv = dev_get_drvdata(dev);
        bool is_sec1 = has_ftr_sec1(priv);
@@ -1113,9 +1110,18 @@ static void ipsec_esp_decrypt_swauth_done(struct device 
*dev,
        ipsec_esp_unmap(dev, edesc, req, false);
 
        if (!err) {
+               char icvdata[SHA512_DIGEST_SIZE];
+               int nents = edesc->dst_nents ? : 1;
+               unsigned int len = req->assoclen + req->cryptlen;
+
                /* auth check */
-               sg = sg_last(req->dst, edesc->dst_nents ? : 1);
-               icv = (char *)sg_virt(sg) + sg->length - authsize;
+               if (nents > 1) {
+                       sg_pcopy_to_buffer(req->dst, nents, icvdata, authsize,
+                                          len - authsize);
+                       icv = icvdata;
+               } else {
+                       icv = (char *)sg_virt(req->dst) + len - authsize;
+               }
 
                if (edesc->dma_len) {
                        if (is_sec1)
@@ -1537,7 +1543,6 @@ static int aead_decrypt(struct aead_request *req)
        struct talitos_ctx *ctx = crypto_aead_ctx(authenc);
        struct talitos_private *priv = dev_get_drvdata(ctx->dev);
        struct talitos_edesc *edesc;
-       struct scatterlist *sg;
        void *icvdata;
 
        /* allocate extended descriptor */
@@ -1571,9 +1576,8 @@ static int aead_decrypt(struct aead_request *req)
        else
                icvdata = &edesc->link_tbl[0];
 
-       sg = sg_last(req->src, edesc->src_nents ? : 1);
-
-       memcpy(icvdata, (char *)sg_virt(sg) + sg->length - authsize, authsize);
+       sg_pcopy_to_buffer(req->src, edesc->src_nents ? : 1, icvdata, authsize,
+                          req->assoclen + req->cryptlen - authsize);
 
        return ipsec_esp(edesc, req, false, ipsec_esp_decrypt_swauth_done);
 }
-- 
2.13.3