Merge patch series "Integrate MbedTLS v3.6 LTS with U-Boot"

Raymond Mao <raymond.mao@linaro.org> says:
Integrate MbedTLS v3.6 LTS (currently v3.6.0) with U-Boot.

Motivations:
------------

1. MbedTLS is well maintained with LTS versions.
2. LWIP is integrated with MbedTLS and easily to enable HTTPS.
3. MbedTLS recently switched license back to GPLv2.

Prerequisite:
-------------

This patch series requires mbedtls git repo to be added as a
subtree to the main U-Boot repo via:
    $ git subtree add --prefix lib/mbedtls/external/mbedtls \
          https://github.com/Mbed-TLS/mbedtls.git \
          v3.6.0 --squash
Moreover, due to the Windows-style files from mbedtls git repo,
we need to convert the CRLF endings to LF and do a commit manually:
    $ git add --renormalize .
    $ git commit

New Kconfig options:
--------------------

`MBEDTLS_LIB` is for MbedTLS general switch.
`MBEDTLS_LIB_CRYPTO` is for replacing original digest and crypto libs with
MbedTLS.
`MBEDTLS_LIB_CRYPTO_ALT` is for using original U-Boot crypto libs as
MbedTLS crypto alternatives.
`MBEDTLS_LIB_X509` is for replacing original X509, PKCS7, MSCode, ASN1,
and Pubkey parser with MbedTLS.
By default `MBEDTLS_LIB_CRYPTO_ALT` and `MBEDTLS_LIB_X509` are selected
when `MBEDTLS_LIB` is enabled.
`LEGACY_CRYPTO` is introduced as a main switch for legacy crypto library.
`LEGACY_CRYPTO_BASIC` is for the basic crypto functionalities and
`LEGACY_CRYPTO_CERT` is for the certificate related functionalities.
For each of the algorithm, a pair of `<alg>_LEGACY` and `<alg>_MBEDTLS`
Kconfig options are introduced. Meanwhile, `SPL_` Kconfig options are
introduced.

In this patch set, MBEDTLS_LIB, MBEDTLS_LIB_CRYPTO and MBEDTLS_LIB_X509
are by default enabled in qemu_arm64_defconfig and sandbox_defconfig
for testing purpose.

Patches for external MbedTLS project:
-------------------------------------

Since U-Boot uses Microsoft Authentication Code to verify PE/COFFs
executables which is not supported by MbedTLS at the moment,
addtional patches for MbedTLS are created to adapt with the EFI loader:
1. Decoding of Microsoft Authentication Code.
2. Decoding of PKCS#9 Authenticate Attributes.
3. Extending MbedTLS PKCS#7 lib to support multiple signer's certificates.
4. MbedTLS native test suites for PKCS#7 signer's info.

All above 4 patches (tagged with `mbedtls/external`) are submitted to
MbedTLS project and being reviewed, eventually they should be part of
MbedTLS LTS release.
But before that, please merge them into U-Boot, otherwise the building
will be broken when MBEDTLS_LIB_X509 is enabled.

See below PR link for the reference:
https://github.com/Mbed-TLS/mbedtls/pull/9001

Miscellaneous:
--------------

Optimized MbedTLS library size by tailoring the config file
and disabling all unnecessary features for EFI loader.
From v2, original libs (rsa, asn1_decoder, rsa_helper, md5, sha1, sha256,
sha512) are completely replaced when MbedTLS is enabled.
From v3, the size-growth is slightly reduced by refactoring Hash functions.
From v6, smaller implementations for SHA256 and SHA512 are enabled and
target size reduce significantly.
Target(QEMU arm64) size-growth when enabling MbedTLS:
v1: 6.03%
v2: 4.66%
v3 - v5: 4.55%
v6: 2.90%

Tests done:
-----------

EFI Secure Boot test (EFI variables loading and verifying, EFI signed image
verifying and booting) via U-Boot console.
EFI Secure Boot and Capsule sandbox test passed.

Known issues:
-------------

None.

Link: https://lore.kernel.org/u-boot/20241003215112.3103601-1-raymond.mao@linaro.org/

1 files changed, 64 insertions, 0 deletions

diff --git a/lib/crypto/x509_helper.c b/lib/crypto/x509_helper.c
new file mode 100644
index 00000000000..87e8ff67ae1
--- /dev/null
+++ b/lib/crypto/x509_helper.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * X509 helper functions
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+#include <linux/err.h>
+#include <crypto/public_key.h>
+#include <crypto/x509_parser.h>
+
+/*
+ * Check for self-signedness in an X.509 cert and if found, check the signature
+ * immediately if we can.
+ */
+int x509_check_for_self_signed(struct x509_certificate *cert)
+{
+	int ret = 0;
+
+	if (cert->raw_subject_size != cert->raw_issuer_size ||
+	    memcmp(cert->raw_subject, cert->raw_issuer,
+		   cert->raw_issuer_size))
+		goto not_self_signed;
+
+	if (cert->sig->auth_ids[0] || cert->sig->auth_ids[1]) {
+		/*
+		 * If the AKID is present it may have one or two parts. If
+		 * both are supplied, both must match.
+		 */
+		bool a = asymmetric_key_id_same(cert->skid,
+						cert->sig->auth_ids[1]);
+		bool b = asymmetric_key_id_same(cert->id,
+						cert->sig->auth_ids[0]);
+
+		if (!a && !b)
+			goto not_self_signed;
+
+		ret = -EKEYREJECTED;
+		if (((a && !b) || (b && !a)) &&
+		    cert->sig->auth_ids[0] && cert->sig->auth_ids[1])
+			goto out;
+	}
+
+	ret = -EKEYREJECTED;
+	if (strcmp(cert->pub->pkey_algo, cert->sig->pkey_algo))
+		goto out;
+
+	ret = public_key_verify_signature(cert->pub, cert->sig);
+	if (ret == -ENOPKG) {
+		cert->unsupported_sig = true;
+		goto not_self_signed;
+	}
+	if (ret < 0)
+		goto out;
+
+	pr_devel("Cert Self-signature verified");
+	cert->self_signed = true;
+
+out:
+	return ret;
+
+not_self_signed:
+	return 0;
+}