linux-kernel - [RFC v3 03/27] X.509: Parse Subject Alternative Name in certificates

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260211032935.2705841-4-alistair.francis@wdc.com>
Date: Wed, 11 Feb 2026 13:29:10 +1000
From: alistair23@...il.com
To: bhelgaas@...gle.com,
	lukas@...ner.de,
	rust-for-linux@...r.kernel.org,
	akpm@...ux-foundation.org,
	linux-pci@...r.kernel.org,
	Jonathan.Cameron@...wei.com,
	linux-cxl@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: alex.gaynor@...il.com,
	benno.lossin@...ton.me,
	boqun.feng@...il.com,
	a.hindborg@...nel.org,
	gary@...yguo.net,
	bjorn3_gh@...tonmail.com,
	tmgross@...ch.edu,
	alistair23@...il.com,
	ojeda@...nel.org,
	wilfred.mallawa@....com,
	aliceryhl@...gle.com,
	Alistair Francis <alistair.francis@....com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Dan Williams <dan.j.williams@...el.com>
Subject: [RFC v3 03/27] X.509: Parse Subject Alternative Name in certificates

From: Lukas Wunner <lukas@...ner.de>

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@...ner.de>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@....com>
Reviewed-by: Alistair Francis <alistair.francis@....com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Acked-by: Dan Williams <dan.j.williams@...el.com>
---
 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 2fe094f5caf3..363acd87dba1 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -596,6 +596,15 @@ 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 8b68e720693a..4e6a05a8c7a6 100644
--- a/include/keys/x509-parser.h
+++ b/include/keys/x509-parser.h
@@ -38,6 +38,8 @@ 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;
-- 
2.52.0