Re: [PATCH v2 02/18] X.509: Parse Subject Alternative Name in certificates

[Alistair Francis <Alistair.Francis@wdc.com>]

On Sun, 2024-06-30 at 21:37 +0200, Lukas Wunner wrote:
> The upcoming support for PCI device authentication with CMA-SPDM
> (PCIe r6.1 sec 6.31) requires validating the Subject Alternative Name
> in X.509 certificates.
> 
> Store a pointer to the Subject Alternative Name upon parsing for
> consumption by CMA-SPDM.
> 
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Acked-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  crypto/asymmetric_keys/x509_cert_parser.c | 9 +++++++++
>  include/keys/x509-parser.h                | 2 ++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c
> b/crypto/asymmetric_keys/x509_cert_parser.c
> index 25cc4273472f..92314e4854f1 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -588,6 +588,15 @@ int x509_process_extension(void *context, size_t
> hdrlen,
>  		return 0;
>  	}
>  
> +	if (ctx->last_oid == OID_subjectAltName) {
> +		if (ctx->cert->raw_san)
> +			return -EBADMSG;
> +
> +		ctx->cert->raw_san = v;
> +		ctx->cert->raw_san_size = vlen;
> +		return 0;
> +	}
> +
>  	if (ctx->last_oid == OID_keyUsage) {
>  		/*
>  		 * Get hold of the keyUsage bit string
> diff --git a/include/keys/x509-parser.h b/include/keys/x509-parser.h
> index 37436a5c7526..8e450befe3b9 100644
> --- a/include/keys/x509-parser.h
> +++ b/include/keys/x509-parser.h
> @@ -36,6 +36,8 @@ struct x509_certificate {
>  	unsigned	raw_subject_size;
>  	unsigned	raw_skid_size;
>  	const void	*raw_skid;		/* Raw subjectKeyId
> in ASN.1 */
> +	const void	*raw_san;		/* Raw
> subjectAltName in ASN.1 */
> +	unsigned	raw_san_size;
>  	unsigned	index;
>  	bool		seen;			/* Infinite
> recursion prevention */
>  	bool		verified;