Re: [PATCH v3 1/3] x509: Detect sm2 keys by their parameters OID

[Jarkko Sakkinen <jarkko@kernel.org>]

On Wed, 2021-01-27 at 07:33 -0500, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> Detect whether a key is an sm2 type of key by its OID in the parameters
> array rather than assuming that everything under OID_id_ecPublicKey
> is sm2, which is not the case.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
>  crypto/asymmetric_keys/x509_cert_parser.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 52c9b455fc7d..4643fe5ed69a 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -459,6 +459,7 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>                           const void *value, size_t vlen)
>  {
>         struct x509_parse_context *ctx = context;
> +       enum OID oid;
>  
>         ctx->key_algo = ctx->last_oid;
>         switch (ctx->last_oid) {
> @@ -470,7 +471,17 @@ int x509_extract_key_data(void *context, size_t hdrlen,
>                 ctx->cert->pub->pkey_algo = "ecrdsa";
>                 break;
>         case OID_id_ecPublicKey:
> -               ctx->cert->pub->pkey_algo = "sm2";
> +               if (ctx->params_size < 2)

Either a named constant, or at least a comment instead of just '2'.


> +                       return -ENOPKG;
> +
> +               oid = look_up_OID(ctx->params + 2, ctx->params_size - 2);
> +               switch (oid) {
> +               case OID_sm2:
> +                       ctx->cert->pub->pkey_algo = "sm2";
> +                       break;
> +               default:
> +                       return -ENOPKG;
> +               }
>                 break;
>         default:
>                 return -ENOPKG;

/Jarkko