GNUTLS has deprecated use of externally provided diffie-hellman
parameters. Since 3.6.0 it will automatically negotiate DH params
in accordance with RFC7919.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
crypto/tlscreds.c | 24 ++++++++----------------
crypto/tlscredsanon.c | 6 ++++--
crypto/tlscredspsk.c | 6 ++++--
crypto/tlscredsx509.c | 4 +++-
docs/about/deprecated.rst | 9 +++++++++
docs/system/tls.rst | 12 +++++++-----
6 files changed, 35 insertions(+), 26 deletions(-)
diff --git a/crypto/tlscreds.c b/crypto/tlscreds.c
index 9912e3ffbf..3d25efe425 100644
--- a/crypto/tlscreds.c
+++ b/crypto/tlscreds.c
@@ -22,6 +22,7 @@
#include "qapi/error.h"
#include "qapi-types-crypto.h"
#include "qemu/module.h"
+#include "qemu/error-report.h"
#include "tlscredspriv.h"
#include "trace.h"
@@ -38,22 +39,7 @@ qcrypto_tls_creds_get_dh_params_file(QCryptoTLSCreds *creds,
trace_qcrypto_tls_creds_load_dh(creds, filename ? filename : "<generated>");
- if (filename == NULL) {
- ret = gnutls_dh_params_init(dh_params);
- if (ret < 0) {
- error_setg(errp, "Unable to initialize DH parameters: %s",
- gnutls_strerror(ret));
- return -1;
- }
- ret = gnutls_dh_params_generate2(*dh_params, DH_BITS);
- if (ret < 0) {
- gnutls_dh_params_deinit(*dh_params);
- *dh_params = NULL;
- error_setg(errp, "Unable to generate DH parameters: %s",
- gnutls_strerror(ret));
- return -1;
- }
- } else {
+ if (filename != NULL) {
GError *gerr = NULL;
gchar *contents;
gsize len;
@@ -67,6 +53,10 @@ qcrypto_tls_creds_get_dh_params_file(QCryptoTLSCreds *creds,
g_error_free(gerr);
return -1;
}
+ warn_report_once("Use of an external DH parameters file '%s' is "
+ "deprecated and will be removed in a future release",
+ filename);
+
data.data = (unsigned char *)contents;
data.size = len;
ret = gnutls_dh_params_init(dh_params);
@@ -87,6 +77,8 @@ qcrypto_tls_creds_get_dh_params_file(QCryptoTLSCreds *creds,
filename, gnutls_strerror(ret));
return -1;
}
+ } else {
+ *dh_params = NULL;
}
return 0;
diff --git a/crypto/tlscredsanon.c b/crypto/tlscredsanon.c
index 646574d6ae..1551382e1f 100644
--- a/crypto/tlscredsanon.c
+++ b/crypto/tlscredsanon.c
@@ -68,8 +68,10 @@ qcrypto_tls_creds_anon_load(QCryptoTLSCredsAnon *creds,
return -1;
}
- gnutls_anon_set_server_dh_params(box->data.anonserver,
- box->dh_params);
+ if (box->dh_params) {
+ gnutls_anon_set_server_dh_params(box->data.anonserver,
+ box->dh_params);
+ }
} else {
ret = gnutls_anon_allocate_client_credentials(&box->data.anonclient);
if (ret < 0) {
diff --git a/crypto/tlscredspsk.c b/crypto/tlscredspsk.c
index 8879c84ea7..e1b1e1a613 100644
--- a/crypto/tlscredspsk.c
+++ b/crypto/tlscredspsk.c
@@ -129,8 +129,10 @@ qcrypto_tls_creds_psk_load(QCryptoTLSCredsPSK *creds,
gnutls_strerror(ret));
goto cleanup;
}
- gnutls_psk_set_server_dh_params(box->data.pskserver,
- box->dh_params);
+ if (box->dh_params) {
+ gnutls_psk_set_server_dh_params(box->data.pskserver,
+ box->dh_params);
+ }
} else {
box = qcrypto_tls_creds_box_new_client(GNUTLS_CRD_PSK);
diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c
index 397ff4caa9..e28fcdc6ff 100644
--- a/crypto/tlscredsx509.c
+++ b/crypto/tlscredsx509.c
@@ -683,7 +683,9 @@ qcrypto_tls_creds_x509_load(QCryptoTLSCredsX509 *creds,
errp) < 0) {
return -1;
}
- gnutls_certificate_set_dh_params(box->data.cert, box->dh_params);
+ if (box->dh_params) {
+ gnutls_certificate_set_dh_params(box->data.cert, box->dh_params);
+ }
}
creds->parent_obj.box = g_steal_pointer(&box);
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 4ee98d6646..03e29915f0 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -385,6 +385,15 @@ Options are:
- move backing file to NVDIMM storage and keep ``pmem=on``
(to have NVDIMM with persistence guaranties).
+Using an external DH (Diffie-Hellman) parameters file (since 10.2)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+Loading of external Diffie-Hellman parameters from a 'dh-params.pem'
+file is deprecated and will be removed with no replacement in a
+future release. Where no 'dh-params.pem' file is provided, the DH
+parameters will be automatically negotiated in accordance with
+RFC7919.
+
Device options
--------------
diff --git a/docs/system/tls.rst b/docs/system/tls.rst
index a4f6781d62..44c4bf04e9 100644
--- a/docs/system/tls.rst
+++ b/docs/system/tls.rst
@@ -251,11 +251,13 @@ When specifying the object, the ``dir`` parameters specifies which
directory contains the credential files. This directory is expected to
contain files with the names mentioned previously, ``ca-cert.pem``,
``server-key.pem``, ``server-cert.pem``, ``client-key.pem`` and
-``client-cert.pem`` as appropriate. It is also possible to include a set
-of pre-generated Diffie-Hellman (DH) parameters in a file
-``dh-params.pem``, which can be created using the
-``certtool --generate-dh-params`` command. If omitted, QEMU will
-dynamically generate DH parameters when loading the credentials.
+``client-cert.pem`` as appropriate.
+
+While it is possible to include a set of pre-generated Diffie-Hellman
+(DH) parameters in a file ``dh-params.pem``, this facility is now
+deprecated and will be removed in a future release. When omitted the
+DH parameters will be automatically negotiated in accordance with
+RFC7919.
The ``endpoint`` parameter indicates whether the credentials will be
used for a network client or server, and determines which PEM files are
--
2.51.1