[dpdk-dev] [PATCH] crypto/openssl: fix usage of non constant time memcmp for mac and signature

Trahe, Fiona fiona.trahe at intel.com
Fri May 31 16:53:30 CEST 2019



> -----Original Message-----
> From: Kusztal, ArkadiuszX
> Sent: Friday, May 31, 2019 7:59 AM
> To: dev at dpdk.org
> Cc: akhil.goyal at nxp.com; Trahe, Fiona <fiona.trahe at intel.com>; Doherty, Declan
> <declan.doherty at intel.com>; Kusztal, ArkadiuszX <arkadiuszx.kusztal at intel.com>
> Subject: [PATCH] crypto/openssl: fix usage of non constant time memcmp for mac and signature
> 
> ANSI C memcmp is not constant time function per spec so it should
> be avoided in cryptography usage.
> 
> Fixes: d61f70b4c918 ("crypto/libcrypto: add driver for OpenSSL library")
> 
> Signed-off-by: Arek Kusztal <arkadiuszx.kusztal at intel.com>
> ---
>  drivers/crypto/openssl/rte_openssl_pmd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/crypto/openssl/rte_openssl_pmd.c b/drivers/crypto/openssl/rte_openssl_pmd.c
> index 6504959..73ce383 100644
> --- a/drivers/crypto/openssl/rte_openssl_pmd.c
> +++ b/drivers/crypto/openssl/rte_openssl_pmd.c
> @@ -1529,7 +1529,7 @@ process_openssl_auth_op(struct openssl_qp *qp, struct rte_crypto_op *op,
>  	}
> 
>  	if (sess->auth.operation == RTE_CRYPTO_AUTH_OP_VERIFY) {
> -		if (memcmp(dst, op->sym->auth.digest.data,
> +		if (CRYPTO_memcmp(dst, op->sym->auth.digest.data,
>  				sess->auth.digest_length) != 0) {
>  			op->status = RTE_CRYPTO_OP_STATUS_AUTH_FAILED;
>  		}
> @@ -1914,7 +1914,7 @@ process_openssl_rsa_op(struct rte_crypto_op *cop,
>  				"Length of public_decrypt %d "
>  				"length of message %zd\n",
>  				ret, op->rsa.message.length);
> -		if ((ret <= 0) || (memcmp(tmp, op->rsa.message.data,
> +		if ((ret <= 0) || (CRYPTO_memcmp(tmp, op->rsa.message.data,
>  				op->rsa.message.length))) {
>  			OPENSSL_LOG(ERR, "RSA sign Verification failed");
>  			cop->status = RTE_CRYPTO_OP_STATUS_ERROR;
> --
> 2.1.0
Hadn't heard of that time const fn before so just read up on it - interesting.
Acked-by: Fiona Trahe <fiona.trahe at intel.com>




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