From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 28289270557; Mon, 28 Jul 2025 13:54:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753710865; cv=none; b=rjihfwttdtlDbh0bdM4/VmRjIwAMB5uF0fcEG9Dd3/cyNPodS0MJdcAbHcfDYH1O9I8X1H8wod1lzMKtLZPeT6hYZBgLGNNeyTqMcPXsceXWGRIP72unrzygmCGyey6cV+GAhS5sNi9tGqRhLdG54XbnRdGlyUowhU/hsUZpFTQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753710865; c=relaxed/simple; bh=GTTAsUvGA0z7kzwZp8HnqrA/zR5zZGrXrfASn4SucGI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t43FNH0H5kinny5+4fz/1cmkPeWY7GuD4eKTFvOlqndeqMWCA6AIABBN1M7rvXnmHlG5jFZBA50FlltzfKwrkTB2Bvxvkp8hv7Y6LaVVZazPFm2E0OD4mYHRH4687jnllk9xiHoO/CF9SJHiNjje9yrtw+1XUp9ZrV/KvIdmInY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oRFmya0a; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oRFmya0a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A62B6C4CEF8; Mon, 28 Jul 2025 13:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753710865; bh=GTTAsUvGA0z7kzwZp8HnqrA/zR5zZGrXrfASn4SucGI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oRFmya0a4DXWNnlwzGx9XgWsjNEjKrmnZTPJ3C1+M4bCQiN+XfE+VuUFk6lf1ntuG TwS9+LHT9UjkSgPBjnwKvHvrUFw+LRR0DmK1A8xq2sKPNVGCC735vWbf5qKtdh5MC9 EEDLFeZjMT85vMe9BzRfeJl7yfc+oFUdSmx+SWduIofbW4J77g0dRtQnnUF4Kj2/4C TKWnnS39yiVqjgP/1TeH90xbYcK74Vbqvtj17MJwNThHfKrQJZtarSgPJeJmaWYOwT ZsSQKQ8ZUa8MTM7kR9aXqTs1Xu/S7Ek0reaMCeq+AtCQ/W2qMfWsXLTNsGzPAF8209 5qS1uUJ0cKZfg== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev, kvmarm@lists.linux.dev Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, aik@amd.com, lukas@wunner.de, Samuel Ortiz , Xu Yilun , Jason Gunthorpe , Suzuki K Poulose , Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , Oliver Upton , Dan Williams , Jonathan Cameron Subject: [RFC PATCH v1 18/38] X.509: Move certificate length retrieval into new helper Date: Mon, 28 Jul 2025 19:21:55 +0530 Message-ID: <20250728135216.48084-19-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250728135216.48084-1-aneesh.kumar@kernel.org> References: <20250728135216.48084-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Lukas Wunner The upcoming in-kernel SPDM library (Security Protocol and Data Model, https://www.dmtf.org/dsp/DSP0274) needs to retrieve the length from ASN.1 DER-encoded X.509 certificates. Such code already exists in x509_load_certificate_list(), so move it into a new helper for reuse by SPDM. Export the helper so that SPDM can be tristate. (Some upcoming users of the SPDM libray may be modular, such as SCSI and ATA.) No functional change intended. Signed-off-by: Lukas Wunner Reviewed-by: Dan Williams Reviewed-by: Jonathan Cameron --- crypto/asymmetric_keys/x509_loader.c | 38 +++++++++++++++++++--------- include/keys/asymmetric-type.h | 2 ++ 2 files changed, 28 insertions(+), 12 deletions(-) diff --git a/crypto/asymmetric_keys/x509_loader.c b/crypto/asymmetric_keys/x509_loader.c index a41741326998..25ff027fad1d 100644 --- a/crypto/asymmetric_keys/x509_loader.c +++ b/crypto/asymmetric_keys/x509_loader.c @@ -4,28 +4,42 @@ #include #include +ssize_t x509_get_certificate_length(const u8 *p, unsigned long buflen) +{ + ssize_t plen; + + /* Each cert begins with an ASN.1 SEQUENCE tag and must be more + * than 256 bytes in size. + */ + if (buflen < 4) + return -EINVAL; + + if (p[0] != 0x30 && + p[1] != 0x82) + return -EINVAL; + + plen = (p[2] << 8) | p[3]; + plen += 4; + if (plen > buflen) + return -EINVAL; + + return plen; +} +EXPORT_SYMBOL_GPL(x509_get_certificate_length); + int x509_load_certificate_list(const u8 cert_list[], const unsigned long list_size, const struct key *keyring) { key_ref_t key; const u8 *p, *end; - size_t plen; + ssize_t plen; p = cert_list; end = p + list_size; while (p < end) { - /* Each cert begins with an ASN.1 SEQUENCE tag and must be more - * than 256 bytes in size. - */ - if (end - p < 4) - goto dodgy_cert; - if (p[0] != 0x30 && - p[1] != 0x82) - goto dodgy_cert; - plen = (p[2] << 8) | p[3]; - plen += 4; - if (plen > end - p) + plen = x509_get_certificate_length(p, end - p); + if (plen < 0) goto dodgy_cert; key = key_create_or_update(make_key_ref(keyring, 1), diff --git a/include/keys/asymmetric-type.h b/include/keys/asymmetric-type.h index 69a13e1e5b2e..e2af07fec3c6 100644 --- a/include/keys/asymmetric-type.h +++ b/include/keys/asymmetric-type.h @@ -84,6 +84,8 @@ extern struct key *find_asymmetric_key(struct key *keyring, const struct asymmetric_key_id *id_2, bool partial); +ssize_t x509_get_certificate_length(const u8 *p, unsigned long buflen); + int x509_load_certificate_list(const u8 cert_list[], const unsigned long list_size, const struct key *keyring); -- 2.43.0