[RFC] [PATCH 4/5] authenc: Check if the IV is already added to the scatterlist

[Steffen Klassert <steffen.klassert@secunet.com>]

aead eseqiv needs to add the IV to the scatterlist itself.
So check if the IV is already contained in the scatterlist
and add it just if it is not already there.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 crypto/authenc.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/crypto/authenc.c b/crypto/authenc.c
index 5793b64..e11029a 100644
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -157,15 +157,16 @@ static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
 
 	dstp = sg_page(dst);
 	vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
+	cryptlen = req->cryptlen;
 
-	if (ivsize) {
+	if (ivsize && !(aead_request_flags(req) & CRYPTO_TFM_REQ_SG_HAS_IV)) {
 		sg_init_table(cipher, 2);
 		sg_set_buf(cipher, iv, ivsize);
 		authenc_chain(cipher, dst, vdst == iv + ivsize);
 		dst = cipher;
+		cryptlen += ivsize;
 	}
 
-	cryptlen = req->cryptlen + ivsize;
 	hash = crypto_authenc_hash(req, flags, dst, cryptlen);
 	if (IS_ERR(hash))
 		return PTR_ERR(hash);
-- 
1.5.4.2