Re: [PATCH 4/9] tls: Support peer certificates that use ECDSA

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

On Mon, 18 Jul 2022, Denis Kenzior wrote:

> ---
> ell/tls.c | 22 +++++++++++++++++++---
> 1 file changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/ell/tls.c b/ell/tls.c
> index b2f7411f3b36..75b9d45c6523 100644
> --- a/ell/tls.c
> +++ b/ell/tls.c
> @@ -1899,6 +1899,8 @@ static void tls_handle_certificate(struct l_tls *tls,
> 	bool dummy;
> 	const char *error_str;
> 	char *subject_str;
> +	enum l_key_cipher_type format_type;
> +	enum l_checksum_type checksum_type;
>
> 	if (len < 3)
> 		goto decode_error;
> @@ -2028,9 +2030,23 @@ static void tls_handle_certificate(struct l_tls *tls,
> 		return;
> 	}
>
> -	if (!l_key_get_info(tls->peer_pubkey, L_KEY_RSA_PKCS1_V1_5,
> -					L_CHECKSUM_NONE, &tls->peer_pubkey_size,
> -					&dummy)) {
> +	switch (l_cert_get_pubkey_type(tls->peer_cert)) {
> +	case L_CERT_KEY_RSA:
> +		format_type = L_KEY_RSA_PKCS1_V1_5;
> +		checksum_type = L_CHECKSUM_NONE;
> +		break;
> +	case L_CERT_KEY_ECC:
> +		format_type = L_KEY_ECDSA_X962;
> +		checksum_type = L_CHECKSUM_SHA1;
> +		break;
> +	case L_CERT_KEY_UNKNOWN:

Hi Denis,

I needed to add

 	default:

here to get it to build. Details below.

> +		TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, 0,
> +				"Unknown public key type");
> +		return;
> +	}
> +
> +	if (!l_key_get_info(tls->peer_pubkey, format_type, checksum_type,
> +				&tls->peer_pubkey_size, &dummy)) {

The ell (standalone, bootstrap-configure) build fails here with 
gcc12/Fedora36:

ell/tls.c:2061:14: error: 'checksum_type' may be used uninitialized [-Werror=maybe-uninitialized]
ell/tls.c:2061:14: error: 'format_type' may be used uninitialized [-Werror=maybe-uninitialized]

Apparently gcc12 can't track that -Werror=switch-enum is in use in 
combination with -Werror=maybe-uninitialized, and doesn't understand that 
the switch statement above does guarantee initialization.

> 		TLS_DISCONNECT(TLS_ALERT_INTERNAL_ERROR, 0,
> 				"Can't l_key_get_info for peer public key");
>
> -- 
> 2.35.1
>
>
>

--
Mat Martineau
Intel