From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C8E88C83F17 for ; Tue, 15 Jul 2025 09:31:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ubbzM-0007If-1u; Tue, 15 Jul 2025 05:30:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubbyy-00076T-5i for qemu-devel@nongnu.org; Tue, 15 Jul 2025 05:29:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubbyv-0005N3-G2 for qemu-devel@nongnu.org; Tue, 15 Jul 2025 05:29:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752571787; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4XefknK1FQqAYXcPQExbfo1ksKosHasD/3eYnECtFXw=; b=gAxpSFbQMq7tM9QTV048T4lcUhIOch2UofdxWrVoC89982Po3ETcZKxXEo9Ux3OpjP3hUK MTNGLO62hVGLGTIBb1din9kabwSoY9/HtBvKVGgV0OZZCSC5wZFN/S5RECxqZ7t4BLFg51 TnIP62crZQupd5NplQmSRI3b+89/rOk= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-568-CRs08kS5ND6I8vctsL0K7Q-1; Tue, 15 Jul 2025 05:29:43 -0400 X-MC-Unique: CRs08kS5ND6I8vctsL0K7Q-1 X-Mimecast-MFC-AGG-ID: CRs08kS5ND6I8vctsL0K7Q_1752571782 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9AB0B18011EE; Tue, 15 Jul 2025 09:29:42 +0000 (UTC) Received: from toolbx.redhat.com (unknown [10.42.28.173]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7F03F1977029; Tue, 15 Jul 2025 09:29:41 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Henry Kleynhans Subject: [PATCH 4/7] crypto: only verify CA certs in chain of trust Date: Tue, 15 Jul 2025 10:29:29 +0100 Message-ID: <20250715092932.1395271-5-berrange@redhat.com> In-Reply-To: <20250715092932.1395271-1-berrange@redhat.com> References: <20250715092932.1395271-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Henry Kleynhans The CA file provided to qemu may contain CA certificates which do not form part of the chain of trust for the specific certificate we are sanity checking. This patch changes the sanity checking from validating every CA certificate to only checking the CA certificates which are part of the chain of trust (issuer chain). Other certificates are ignored. Reviewed-by: Daniel P. Berrangé Signed-off-by: Henry Kleynhans Signed-off-by: Daniel P. Berrangé --- crypto/tlscredsx509.c | 57 ++++++++++++++++++++++++--- tests/unit/test-crypto-tlscredsx509.c | 25 +++++++++++- 2 files changed, 75 insertions(+), 7 deletions(-) diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c index 3e3ec4971f..ec6ff43af2 100644 --- a/crypto/tlscredsx509.c +++ b/crypto/tlscredsx509.c @@ -307,6 +307,51 @@ qcrypto_tls_creds_check_cert(QCryptoTLSCredsX509 *creds, return 0; } +static int +qcrypto_tls_creds_check_authority_chain(QCryptoTLSCredsX509 *creds, + gnutls_x509_crt_t cert, + gnutls_x509_crt_t *cacerts, + unsigned int ncacerts, + const char *cacertFile, + bool isServer, + bool isCA, + Error **errp) +{ + gnutls_x509_crt_t *cert_to_check = &cert; + int checking_issuer = 1; + int retval = 0; + + while (checking_issuer) { + checking_issuer = 0; + + if (gnutls_x509_crt_check_issuer(*cert_to_check, + *cert_to_check)) { + /* + * The cert is self-signed indicating we have + * reached the root of trust. + */ + return qcrypto_tls_creds_check_cert( + creds, *cert_to_check, cacertFile, + isServer, isCA, errp); + } + for (int i = 0; i < ncacerts; i++) { + if (gnutls_x509_crt_check_issuer(*cert_to_check, + cacerts[i])) { + retval = qcrypto_tls_creds_check_cert( + creds, cacerts[i], cacertFile, + isServer, isCA, errp); + if (retval < 0) { + return retval; + } + cert_to_check = &cacerts[i]; + checking_issuer = 1; + break; + } + } + } + + return -1; +} static int qcrypto_tls_creds_check_cert_pair(gnutls_x509_crt_t cert, @@ -491,12 +536,12 @@ qcrypto_tls_creds_x509_sanity_check(QCryptoTLSCredsX509 *creds, goto cleanup; } - for (i = 0; i < ncacerts; i++) { - if (qcrypto_tls_creds_check_cert(creds, - cacerts[i], cacertFile, - isServer, true, errp) < 0) { - goto cleanup; - } + if (cert && + qcrypto_tls_creds_check_authority_chain(creds, cert, + cacerts, ncacerts, + cacertFile, isServer, + true, errp) < 0) { + goto cleanup; } if (cert && ncacerts && diff --git a/tests/unit/test-crypto-tlscredsx509.c b/tests/unit/test-crypto-tlscredsx509.c index 2025d75365..78b00401d1 100644 --- a/tests/unit/test-crypto-tlscredsx509.c +++ b/tests/unit/test-crypto-tlscredsx509.c @@ -589,6 +589,12 @@ int main(int argc, char **argv) true, true, GNUTLS_KEY_KEY_CERT_SIGN, false, false, NULL, NULL, 0, 0); + TLS_CERT_REQ(cacertlevel1creq_invalid, cacertrootreq, + "UK", "qemu level 1c invalid", NULL, NULL, NULL, NULL, + true, true, true, + true, true, GNUTLS_KEY_KEY_CERT_SIGN, + false, false, NULL, NULL, + 360, 400); TLS_CERT_REQ(cacertlevel2areq, cacertlevel1areq, "UK", "qemu level 2a", NULL, NULL, NULL, NULL, true, true, true, @@ -617,16 +623,32 @@ int main(int argc, char **argv) cacertlevel2areq.crt, }; + test_tls_write_cert_chain(WORKDIR "cacertchain-ctx.pem", certchain, G_N_ELEMENTS(certchain)); + gnutls_x509_crt_t certchain_with_invalid[] = { + cacertrootreq.crt, + cacertlevel1areq.crt, + cacertlevel1breq.crt, + cacertlevel1creq_invalid.crt, + cacertlevel2areq.crt, + }; + + test_tls_write_cert_chain(WORKDIR "cacertchain-with-invalid-ctx.pem", + certchain_with_invalid, + G_N_ELEMENTS(certchain_with_invalid)); + TLS_TEST_REG(chain1, true, WORKDIR "cacertchain-ctx.pem", servercertlevel3areq.filename, false); TLS_TEST_REG(chain2, false, WORKDIR "cacertchain-ctx.pem", clientcertlevel2breq.filename, false); + TLS_TEST_REG(certchainwithexpiredcert, false, + WORKDIR "cacertchain-with-invalid-ctx.pem", + clientcertlevel2breq.filename, false); /* Some missing certs - first two are fatal, the last * is ok @@ -640,7 +662,6 @@ int main(int argc, char **argv) TLS_TEST_REG(missingclient, false, cacert1req.filename, "clientcertdoesnotexist.pem", false); - ret = g_test_run(); test_tls_discard_cert(&cacertreq); @@ -694,10 +715,12 @@ int main(int argc, char **argv) test_tls_discard_cert(&cacertrootreq); test_tls_discard_cert(&cacertlevel1areq); test_tls_discard_cert(&cacertlevel1breq); + test_tls_discard_cert(&cacertlevel1creq_invalid); test_tls_discard_cert(&cacertlevel2areq); test_tls_discard_cert(&servercertlevel3areq); test_tls_discard_cert(&clientcertlevel2breq); unlink(WORKDIR "cacertchain-ctx.pem"); + unlink(WORKDIR "cacertchain-with-invalid-ctx.pem"); test_tls_cleanup(KEYFILE); rmdir(WORKDIR); -- 2.49.0