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From:   Iuliana Prodan <iuliana.prodan@nxp.com>
To:     Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>
Cc:     linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-imx <linux-imx@nxp.com>
Subject: [PATCH v4] crypto: gcm - restrict assoclen for rfc4543
Date:   Tue, 30 Jul 2019 19:30:33 +0300
Message-Id: <1564504233-26186-1-git-send-email-iuliana.prodan@nxp.com>
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk

Based on seqiv, IPsec ESP and rfc4543/rfc4106 the assoclen can be 16 or
20 bytes.

From esp4/esp6, assoclen is sizeof IP Header. This includes spi, seq_no
and extended seq_no, that is 8 or 12 bytes.
In seqiv, to asscolen is added the IV size (8 bytes).
Therefore, the assoclen, for rfc4543, should be restricted to 16 or 20
bytes, as for rfc4106.

Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Horia Geanta <horia.geanta@nxp.com>
---
Changes since v3:
- use ternary operator for return.

Patch depends on series:
https://patchwork.kernel.org/project/linux-crypto/list/?series=152649
---
 crypto/gcm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/crypto/gcm.c b/crypto/gcm.c
index 2f3b50f..8adf64f 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -1034,12 +1034,14 @@ static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
 
 static int crypto_rfc4543_encrypt(struct aead_request *req)
 {
-	return crypto_rfc4543_crypt(req, true);
+	return crypto_ipsec_check_assoclen(req->assoclen) ?:
+			crypto_rfc4543_crypt(req, true);
 }
 
 static int crypto_rfc4543_decrypt(struct aead_request *req)
 {
-	return crypto_rfc4543_crypt(req, false);
+	return crypto_ipsec_check_assoclen(req->assoclen) ?:
+			crypto_rfc4543_crypt(req, false);
 }
 
 static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
-- 
2.1.0