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 9FAFDCAC59A for ; Fri, 19 Sep 2025 10:12:05 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uzY4g-0002hH-R5; Fri, 19 Sep 2025 06:10:42 -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 1uzY4c-0002fx-CE for qemu-devel@nongnu.org; Fri, 19 Sep 2025 06:10:38 -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 1uzY4Z-0007Ne-Rg for qemu-devel@nongnu.org; Fri, 19 Sep 2025 06:10:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758276630; 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=90T0fE5TCoM86apcPD0Nr1rMxCkCs13+sdEeAAac0VA=; b=aMYuBokhfwoWs6y4kPspN5KT0OUixIqzqQr4yXrm9E8VEU2JbGr6oc+dC9na6mHjKZZF2g TC2rjhAC3CgYqujgRuUU1UVdan/5FrsNW7qVOPSzFNn1dndt09IL3GsjEZLnnBW6xIN2Nt hkoSNFCAXOBEnw/xBace16YhvVNAAK0= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-520-6C6AyPVGMci2iGk7DLKAvQ-1; Fri, 19 Sep 2025 06:10:27 -0400 X-MC-Unique: 6C6AyPVGMci2iGk7DLKAvQ-1 X-Mimecast-MFC-AGG-ID: 6C6AyPVGMci2iGk7DLKAvQ_1758276626 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6660F19560A1; Fri, 19 Sep 2025 10:10:26 +0000 (UTC) Received: from toolbx.redhat.com (unknown [10.42.28.187]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 1290F1800446; Fri, 19 Sep 2025 10:10:24 +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 v2 1/6] crypto: only verify CA certs in chain of trust Date: Fri, 19 Sep 2025 11:10:17 +0100 Message-ID: <20250919101022.1491007-2-berrange@redhat.com> In-Reply-To: <20250919101022.1491007-1-berrange@redhat.com> References: <20250919101022.1491007-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 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=-0.005, 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 cd1f504471..797854ac89 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; + 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, @@ -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