2019-07-30 16:48:22

by Iuliana Prodan

Subject: [PATCH v4] 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 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

2019-08-02 08:39:19

by Herbert Xu

Subject: Re: [PATCH v4] crypto: gcm - restrict assoclen for rfc4543

On Tue, Jul 30, 2019 at 07:30:33PM +0300, Iuliana Prodan wrote:
>
> 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);

Please align it like this:

return crypto_ipsec_check_assoclen(req->assoclen) ?:
crypto_rfc4543_crypt(req, true);

as that's how everything else is aligned in crypto.

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