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 80F2BCCF9E3 for ; Fri, 24 Oct 2025 13:22:16 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vCHiZ-0005h9-6e; Fri, 24 Oct 2025 09:20:31 -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 1vCHi8-0005Uc-Dh for qemu-devel@nongnu.org; Fri, 24 Oct 2025 09:20:06 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vCHi6-0004mX-Bz for qemu-devel@nongnu.org; Fri, 24 Oct 2025 09:20:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1761312001; 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=CCObt3x+cEciUOh6vncOKwvla1QzbKPqBuEb/0PEtVo=; b=MdhfKTuq9K0bkakpZw/mzconBJ916NPKm41mQ94ZkS3OzMpdXxCXOK4oLj63X/KBQLNs5q 9uIyAUmV6QOrG353punHXGleN/eeOpbrkiZ5iZlSSAaDTST7CyQn0WUcUZoTYr6dsHBaxz IbLkw4USva/FwjNH97iJAqfl9NDu51Y= 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-213-Iprb4okpOE6sRGCiK3cGPw-1; Fri, 24 Oct 2025 09:19:57 -0400 X-MC-Unique: Iprb4okpOE6sRGCiK3cGPw-1 X-Mimecast-MFC-AGG-ID: Iprb4okpOE6sRGCiK3cGPw_1761311996 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 6A2A4180A221; Fri, 24 Oct 2025 13:19:56 +0000 (UTC) Received: from toolbx.redhat.com (unknown [10.42.28.2]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 5C4B419540EB; Fri, 24 Oct 2025 13:19:54 +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?= , Eduardo Habkost , Paolo Bonzini , Eric Blake , Henry Kleynhans Subject: [PULL 07/13] crypto: only verify CA certs in chain of trust Date: Fri, 24 Oct 2025 14:19:31 +0100 Message-ID: <20251024131937.56673-8-berrange@redhat.com> In-Reply-To: <20251024131937.56673-1-berrange@redhat.com> References: <20251024131937.56673-1-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=170.10.129.124; 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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 Reviewed-by: Eric Blake Signed-off-by: Henry Kleynhans [DB: changed 'int' to 'bool' in 'checking_issuer' variable] 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 cd1f504471..3df2a33b0b 100644 --- a/crypto/tlscredsx509.c +++ b/crypto/tlscredsx509.c @@ -315,6 +315,51 @@ 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; + bool checking_issuer = true; + int retval = 0; + + while (checking_issuer) { + checking_issuer = false; + + 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 = true; + break; + } + } + } + + return -1; +} static int qcrypto_tls_creds_check_cert_pair(gnutls_x509_crt_t cert, @@ -499,12 +544,12 @@ 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 3c25d75ca1..a7ea5f422d 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); -- 2.50.1