2019-08-02 09:36:20

by Iuliana Prodan

Subject: [PATCH v5] crypto: gcm - restrict assoclen for rfc4543

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 <[email protected]>
Reviewed-by: Horia Geanta <[email protected]>
---
Changes since v4:
- alignment.
---
crypto/gcm.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/crypto/gcm.c b/crypto/gcm.c
index 2f3b50f..7388420 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

2019-08-09 06:21:43

by Herbert Xu

Subject: Re: [PATCH v5] crypto: gcm - restrict assoclen for rfc4543

On Fri, Aug 02, 2019 at 11:47:33AM +0300, Iuliana Prodan wrote:
> 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 <[email protected]>
> Reviewed-by: Horia Geanta <[email protected]>
> ---
> Changes since v4:
> - alignment.
> ---
> crypto/gcm.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt