From: "Daniel P. Berrangé" <berrange@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Daniel P. Berrangé" <berrange@redhat.com>,
matoro <matoro_mailinglist_qemu@matoro.tk>
Subject: [PATCH 7/7] crypto: allow client/server cert chains
Date: Tue, 15 Jul 2025 10:29:32 +0100 [thread overview]
Message-ID: <20250715092932.1395271-8-berrange@redhat.com> (raw)
In-Reply-To: <20250715092932.1395271-1-berrange@redhat.com>
From: matoro <matoro@users.noreply.github.com>
The existing implementation assumes that client/server certificates are
single individual certificates. If using publicly-issued certificates,
or internal CAs that use an intermediate issuer, this is unlikely to be
the case, and they will instead be certificate chains. While this can
be worked around by moving the intermediate certificates to the CA
certificate, which DOES currently support multiple certificates, this
instead allows the issued certificate chains to be used as-is, without
requiring the overhead of shuffling certificates around.
Corresponding libvirt change is available here:
https://gitlab.com/libvirt/libvirt/-/merge_requests/222
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: matoro <matoro_mailinglist_qemu@matoro.tk>
[DB: adapted for code conflicts with multi-CA patch]
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
crypto/tlscredsx509.c | 157 ++++++++++++--------------
tests/unit/test-crypto-tlscredsx509.c | 77 +++++++++++++
2 files changed, 147 insertions(+), 87 deletions(-)
diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c
index d6897ca57b..0b200c5147 100644
--- a/crypto/tlscredsx509.c
+++ b/crypto/tlscredsx509.c
@@ -309,7 +309,8 @@ qcrypto_tls_creds_check_cert(QCryptoTLSCredsX509 *creds,
static int
qcrypto_tls_creds_check_authority_chain(QCryptoTLSCredsX509 *creds,
- gnutls_x509_crt_t cert,
+ gnutls_x509_crt_t *certs,
+ unsigned int ncerts,
gnutls_x509_crt_t *cacerts,
unsigned int ncacerts,
const char *cacertFile,
@@ -317,10 +318,33 @@ qcrypto_tls_creds_check_authority_chain(QCryptoTLSCredsX509 *creds,
bool isCA,
Error **errp)
{
- gnutls_x509_crt_t cert_to_check = cert;
- gnutls_datum_t dn = {};
+ gnutls_x509_crt_t cert_to_check = certs[ncerts - 1];
+ gnutls_datum_t dn = {}, dnissuer = {};
int rv;
+ for (int i = 0; i < (ncerts - 1); i++) {
+ if (!gnutls_x509_crt_check_issuer(certs[i], certs[i + 1])) {
+ rv = gnutls_x509_crt_get_dn2(certs[i], &dn);
+ if (rv < 0) {
+ error_setg(errp, "Unable to fetch cert DN: %s",
+ gnutls_strerror(rv));
+ return -1;
+ }
+ rv = gnutls_x509_crt_get_dn2(certs[i + 1], &dnissuer);
+ if (rv < 0) {
+ gnutls_free(dn.data);
+ error_setg(errp, "Unable to fetch cert DN: %s",
+ gnutls_strerror(rv));
+ return -1;
+ }
+ error_setg(errp, "Cert '%s' does not match issuer of cert '%s'",
+ dnissuer.data, dn.data);
+ gnutls_free(dn.data);
+ gnutls_free(dnissuer.data);
+ return -1;
+ }
+ }
+
for (;;) {
gnutls_x509_crt_t cert_issuer = NULL;
@@ -365,7 +389,8 @@ qcrypto_tls_creds_check_authority_chain(QCryptoTLSCredsX509 *creds,
}
static int
-qcrypto_tls_creds_check_cert_pair(gnutls_x509_crt_t cert,
+qcrypto_tls_creds_check_cert_pair(gnutls_x509_crt_t *certs,
+ size_t ncerts,
const char *certFile,
gnutls_x509_crt_t *cacerts,
size_t ncacerts,
@@ -375,7 +400,7 @@ qcrypto_tls_creds_check_cert_pair(gnutls_x509_crt_t cert,
{
unsigned int status;
- if (gnutls_x509_crt_list_verify(&cert, 1,
+ if (gnutls_x509_crt_list_verify(certs, ncerts,
cacerts, ncacerts,
NULL, 0,
0, &status) < 0) {
@@ -417,66 +442,14 @@ qcrypto_tls_creds_check_cert_pair(gnutls_x509_crt_t cert,
}
-static gnutls_x509_crt_t
-qcrypto_tls_creds_load_cert(QCryptoTLSCredsX509 *creds,
- const char *certFile,
- bool isServer,
- Error **errp)
-{
- gnutls_datum_t data;
- gnutls_x509_crt_t cert = NULL;
- g_autofree char *buf = NULL;
- gsize buflen;
- GError *gerr = NULL;
- int ret = -1;
- int err;
-
- trace_qcrypto_tls_creds_x509_load_cert(creds, isServer, certFile);
-
- err = gnutls_x509_crt_init(&cert);
- if (err < 0) {
- error_setg(errp, "Unable to initialize certificate: %s",
- gnutls_strerror(err));
- goto cleanup;
- }
-
- if (!g_file_get_contents(certFile, &buf, &buflen, &gerr)) {
- error_setg(errp, "Cannot load CA cert list %s: %s",
- certFile, gerr->message);
- g_error_free(gerr);
- goto cleanup;
- }
-
- data.data = (unsigned char *)buf;
- data.size = strlen(buf);
-
- err = gnutls_x509_crt_import(cert, &data, GNUTLS_X509_FMT_PEM);
- if (err < 0) {
- error_setg(errp, isServer ?
- "Unable to import server certificate %s: %s" :
- "Unable to import client certificate %s: %s",
- certFile,
- gnutls_strerror(err));
- goto cleanup;
- }
-
- ret = 0;
-
- cleanup:
- if (ret != 0) {
- gnutls_x509_crt_deinit(cert);
- cert = NULL;
- }
- return cert;
-}
-
-
static int
-qcrypto_tls_creds_load_ca_cert_list(QCryptoTLSCredsX509 *creds,
- const char *certFile,
- gnutls_x509_crt_t **certs,
- unsigned int *ncerts,
- Error **errp)
+qcrypto_tls_creds_load_cert_list(QCryptoTLSCredsX509 *creds,
+ const char *certFile,
+ gnutls_x509_crt_t **certs,
+ unsigned int *ncerts,
+ bool isServer,
+ bool isCA,
+ Error **errp)
{
gnutls_datum_t data;
g_autofree char *buf = NULL;
@@ -499,7 +472,9 @@ qcrypto_tls_creds_load_ca_cert_list(QCryptoTLSCredsX509 *creds,
if (gnutls_x509_crt_list_import2(certs, ncerts, &data,
GNUTLS_X509_FMT_PEM, 0) < 0) {
error_setg(errp,
- "Unable to import CA certificate list %s",
+ isCA ? "Unable to import CA certificate list %s" :
+ (isServer ? "Unable to import server certificate %s" :
+ "Unable to import client certificate %s"),
certFile);
return -1;
}
@@ -515,7 +490,8 @@ qcrypto_tls_creds_x509_sanity_check(QCryptoTLSCredsX509 *creds,
const char *certFile,
Error **errp)
{
- gnutls_x509_crt_t cert = NULL;
+ gnutls_x509_crt_t *certs = NULL;
+ unsigned int ncerts = 0;
gnutls_x509_crt_t *cacerts = NULL;
unsigned int ncacerts = 0;
size_t i;
@@ -523,41 +499,48 @@ qcrypto_tls_creds_x509_sanity_check(QCryptoTLSCredsX509 *creds,
if (certFile &&
access(certFile, R_OK) == 0) {
- cert = qcrypto_tls_creds_load_cert(creds,
- certFile, isServer,
- errp);
- if (!cert) {
+ if (qcrypto_tls_creds_load_cert_list(creds,
+ certFile,
+ &certs,
+ &ncerts,
+ isServer,
+ false,
+ errp) < 0) {
goto cleanup;
}
}
if (access(cacertFile, R_OK) == 0) {
- if (qcrypto_tls_creds_load_ca_cert_list(creds,
- cacertFile,
- &cacerts,
- &ncacerts,
- errp) < 0) {
+ if (qcrypto_tls_creds_load_cert_list(creds,
+ cacertFile,
+ &cacerts,
+ &ncacerts,
+ isServer,
+ true,
+ errp) < 0) {
goto cleanup;
}
}
- if (cert &&
- qcrypto_tls_creds_check_cert(creds,
- cert, certFile, isServer,
- false, errp) < 0) {
- goto cleanup;
+ for (i = 0; i < ncerts; i++) {
+ if (qcrypto_tls_creds_check_cert(creds,
+ certs[i], certFile,
+ isServer, (i != 0), errp) < 0) {
+ goto cleanup;
+ }
}
- if (cert &&
- qcrypto_tls_creds_check_authority_chain(creds, cert,
+ if (ncerts &&
+ qcrypto_tls_creds_check_authority_chain(creds,
+ certs, ncerts,
cacerts, ncacerts,
cacertFile, isServer,
true, errp) < 0) {
goto cleanup;
}
- if (cert && ncacerts &&
- qcrypto_tls_creds_check_cert_pair(cert, certFile, cacerts,
- ncacerts, cacertFile,
+ if (ncerts && ncacerts &&
+ qcrypto_tls_creds_check_cert_pair(certs, ncerts, certFile,
+ cacerts, ncacerts, cacertFile,
isServer, errp) < 0) {
goto cleanup;
}
@@ -565,8 +548,8 @@ qcrypto_tls_creds_x509_sanity_check(QCryptoTLSCredsX509 *creds,
ret = 0;
cleanup:
- if (cert) {
- gnutls_x509_crt_deinit(cert);
+ for (i = 0; i < ncerts; i++) {
+ gnutls_x509_crt_deinit(certs[i]);
}
for (i = 0; i < ncacerts; i++) {
gnutls_x509_crt_deinit(cacerts[i]);
diff --git a/tests/unit/test-crypto-tlscredsx509.c b/tests/unit/test-crypto-tlscredsx509.c
index 78b00401d1..fac6c64cad 100644
--- a/tests/unit/test-crypto-tlscredsx509.c
+++ b/tests/unit/test-crypto-tlscredsx509.c
@@ -577,6 +577,12 @@ int main(int argc, char **argv)
true, true, GNUTLS_KEY_KEY_CERT_SIGN,
false, false, NULL, NULL,
0, 0);
+ TLS_ROOT_REQ(someotherrootreq,
+ "UK", "some other random CA", NULL, NULL, NULL, NULL,
+ true, true, true,
+ true, true, GNUTLS_KEY_KEY_CERT_SIGN,
+ false, false, NULL, NULL,
+ 0, 0);
TLS_CERT_REQ(cacertlevel1areq, cacertrootreq,
"UK", "qemu level 1a", NULL, NULL, NULL, NULL,
true, true, true,
@@ -623,6 +629,32 @@ int main(int argc, char **argv)
cacertlevel2areq.crt,
};
+ gnutls_x509_crt_t cabundle[] = {
+ someotherrootreq.crt,
+ cacertrootreq.crt,
+ };
+
+ gnutls_x509_crt_t servercertchain[] = {
+ servercertlevel3areq.crt,
+ cacertlevel2areq.crt,
+ cacertlevel1areq.crt,
+ };
+
+ gnutls_x509_crt_t servercertchain_incomplete[] = {
+ servercertlevel3areq.crt,
+ cacertlevel2areq.crt,
+ };
+
+ gnutls_x509_crt_t servercertchain_unsorted[] = {
+ servercertlevel3areq.crt,
+ cacertlevel1areq.crt,
+ cacertlevel2areq.crt,
+ };
+
+ gnutls_x509_crt_t clientcertchain[] = {
+ clientcertlevel2breq.crt,
+ cacertlevel1breq.crt,
+ };
test_tls_write_cert_chain(WORKDIR "cacertchain-ctx.pem",
certchain,
@@ -650,6 +682,46 @@ int main(int argc, char **argv)
WORKDIR "cacertchain-with-invalid-ctx.pem",
clientcertlevel2breq.filename, false);
+ test_tls_write_cert_chain(WORKDIR "servercertchain-ctx.pem",
+ servercertchain,
+ G_N_ELEMENTS(servercertchain));
+
+ TLS_TEST_REG(serverchain, true,
+ cacertrootreq.filename,
+ WORKDIR "servercertchain-ctx.pem", false);
+
+ test_tls_write_cert_chain(WORKDIR "cabundle-ctx.pem",
+ cabundle,
+ G_N_ELEMENTS(cabundle));
+
+ TLS_TEST_REG(multiplecaswithchain, true,
+ WORKDIR "cabundle-ctx.pem",
+ WORKDIR "servercertchain-ctx.pem", false);
+
+ test_tls_write_cert_chain(WORKDIR "servercertchain_incomplete-ctx.pem",
+ servercertchain_incomplete,
+ G_N_ELEMENTS(servercertchain_incomplete));
+
+ TLS_TEST_REG(incompleteserverchain, true,
+ cacertrootreq.filename,
+ WORKDIR "servercertchain_incomplete-ctx.pem", true);
+
+ test_tls_write_cert_chain(WORKDIR "servercertchain_unsorted-ctx.pem",
+ servercertchain_unsorted,
+ G_N_ELEMENTS(servercertchain_unsorted));
+
+ TLS_TEST_REG(unsortedserverchain, true,
+ cacertrootreq.filename,
+ WORKDIR "servercertchain_unsorted-ctx.pem", true);
+
+ test_tls_write_cert_chain(WORKDIR "clientcertchain-ctx.pem",
+ clientcertchain,
+ G_N_ELEMENTS(clientcertchain));
+
+ TLS_TEST_REG(clientchain, false,
+ cacertrootreq.filename,
+ WORKDIR "clientcertchain-ctx.pem", false);
+
/* Some missing certs - first two are fatal, the last
* is ok
*/
@@ -719,8 +791,13 @@ int main(int argc, char **argv)
test_tls_discard_cert(&cacertlevel2areq);
test_tls_discard_cert(&servercertlevel3areq);
test_tls_discard_cert(&clientcertlevel2breq);
+ test_tls_discard_cert(&someotherrootreq);
unlink(WORKDIR "cacertchain-ctx.pem");
unlink(WORKDIR "cacertchain-with-invalid-ctx.pem");
+ unlink(WORKDIR "servercertchain-ctx.pem");
+ unlink(WORKDIR "servercertchain_incomplete-ctx.pem");
+ unlink(WORKDIR "servercertchain_unsorted-ctx.pem");
+ unlink(WORKDIR "clientcertchain-ctx.pem");
test_tls_cleanup(KEYFILE);
rmdir(WORKDIR);
--
2.49.0
next prev parent reply other threads:[~2025-07-15 9:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-15 9:29 [PATCH 0/7] crypto: misc fixes and improvements to cert handling Daniel P. Berrangé
2025-07-15 9:29 ` [PATCH 1/7] crypto: stop requiring "key encipherment" usage in x509 certs Daniel P. Berrangé
2025-07-15 9:29 ` [PATCH 2/7] crypto: switch to newer gnutls API for distinguished name Daniel P. Berrangé
2025-07-15 9:29 ` [PATCH 3/7] crypto: load all certificates in X509 CA file Daniel P. Berrangé
2025-07-15 9:29 ` [PATCH 4/7] crypto: only verify CA certs in chain of trust Daniel P. Berrangé
2025-07-15 9:29 ` [PATCH 5/7] crypto: remove extraneous pointer usage in gnutls certs Daniel P. Berrangé
2025-07-15 9:35 ` Philippe Mathieu-Daudé
2025-07-15 9:29 ` [PATCH 6/7] crypto: fix error reporting in cert chain checks Daniel P. Berrangé
2025-07-15 9:29 ` Daniel P. Berrangé [this message]
2025-07-15 9:46 ` [PATCH 7/7] crypto: allow client/server cert chains Philippe Mathieu-Daudé
2025-07-15 16:09 ` Daniel P. Berrangé
2025-07-15 17:26 ` Philippe Mathieu-Daudé
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