qemu-e2k/crypto/tlscredspsk.c

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/*
* QEMU crypto TLS Pre-Shared Keys (PSK) support
*
* Copyright (c) 2018 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "crypto/tlscredspsk.h"
#include "tlscredspriv.h"
#include "qapi/error.h"
#include "qemu/module.h"
#include "qom/object_interfaces.h"
#include "trace.h"
#ifdef CONFIG_GNUTLS
crypto: Make QCryptoTLSCreds* structures private Code consuming the "crypto/tlscreds*.h" APIs doesn't need to access its internals. Move the structure definitions to the "tlscredspriv.h" private header (only accessible by implementations). The public headers (in include/) still forward-declare the structures typedef. Note, tlscreds.c and 3 of the 5 modified source files already include "tlscredspriv.h", so only add it to tls-cipher-suites.c and tlssession.c. Removing the internals from the public header solves a bug introduced by commit 7de2e856533 ("yank: Unregister function when using TLS migration") which made migration/qemu-file-channel.c include "io/channel-tls.h", itself sometime depends on GNUTLS, leading to a build failure on OSX: [2/35] Compiling C object libmigration.fa.p/migration_qemu-file-channel.c.o FAILED: libmigration.fa.p/migration_qemu-file-channel.c.o cc -Ilibmigration.fa.p -I. -I.. -Iqapi [ ... ] -o libmigration.fa.p/migration_qemu-file-channel.c.o -c ../migration/qemu-file-channel.c In file included from ../migration/qemu-file-channel.c:29: In file included from include/io/channel-tls.h:26: In file included from include/crypto/tlssession.h:24: include/crypto/tlscreds.h:28:10: fatal error: 'gnutls/gnutls.h' file not found #include <gnutls/gnutls.h> ^~~~~~~~~~~~~~~~~ 1 error generated. Reported-by: Stefan Weil <sw@weilnetz.de> Suggested-by: Daniel P. Berrangé <berrange@redhat.com> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/407 Fixes: 7de2e856533 ("yank: Unregister function when using TLS migration") Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-06-28 18:09:14 +02:00
#include <gnutls/gnutls.h>
static int
lookup_key(const char *pskfile, const char *username, gnutls_datum_t *key,
Error **errp)
{
const size_t ulen = strlen(username);
GError *gerr = NULL;
char *content = NULL;
char **lines = NULL;
size_t clen = 0, i;
int ret = -1;
if (!g_file_get_contents(pskfile, &content, &clen, &gerr)) {
error_setg(errp, "Cannot read PSK file %s: %s",
pskfile, gerr->message);
g_error_free(gerr);
return -1;
}
lines = g_strsplit(content, "\n", -1);
for (i = 0; lines[i] != NULL; ++i) {
if (strncmp(lines[i], username, ulen) == 0 && lines[i][ulen] == ':') {
key->data = (unsigned char *) g_strdup(&lines[i][ulen + 1]);
key->size = strlen(lines[i]) - ulen - 1;
ret = 0;
goto out;
}
}
error_setg(errp, "Username %s not found in PSK file %s",
username, pskfile);
out:
free(content);
g_strfreev(lines);
return ret;
}
static int
qcrypto_tls_creds_psk_load(QCryptoTLSCredsPSK *creds,
Error **errp)
{
g_autofree char *pskfile = NULL;
g_autofree char *dhparams = NULL;
const char *username;
int ret;
int rv = -1;
gnutls_datum_t key = { .data = NULL };
trace_qcrypto_tls_creds_psk_load(creds,
creds->parent_obj.dir ? creds->parent_obj.dir : "<nodir>");
if (creds->parent_obj.endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
if (creds->username) {
error_setg(errp, "username should not be set when endpoint=server");
goto cleanup;
}
if (qcrypto_tls_creds_get_path(&creds->parent_obj,
QCRYPTO_TLS_CREDS_DH_PARAMS,
false, &dhparams, errp) < 0 ||
qcrypto_tls_creds_get_path(&creds->parent_obj,
QCRYPTO_TLS_CREDS_PSKFILE,
true, &pskfile, errp) < 0) {
goto cleanup;
}
ret = gnutls_psk_allocate_server_credentials(&creds->data.server);
if (ret < 0) {
error_setg(errp, "Cannot allocate credentials: %s",
gnutls_strerror(ret));
goto cleanup;
}
if (qcrypto_tls_creds_get_dh_params_file(&creds->parent_obj, dhparams,
&creds->parent_obj.dh_params,
errp) < 0) {
goto cleanup;
}
gnutls_psk_set_server_credentials_file(creds->data.server, pskfile);
gnutls_psk_set_server_dh_params(creds->data.server,
creds->parent_obj.dh_params);
} else {
if (qcrypto_tls_creds_get_path(&creds->parent_obj,
QCRYPTO_TLS_CREDS_PSKFILE,
true, &pskfile, errp) < 0) {
goto cleanup;
}
if (creds->username) {
username = creds->username;
} else {
username = "qemu";
}
if (lookup_key(pskfile, username, &key, errp) != 0) {
goto cleanup;
}
ret = gnutls_psk_allocate_client_credentials(&creds->data.client);
if (ret < 0) {
error_setg(errp, "Cannot allocate credentials: %s",
gnutls_strerror(ret));
goto cleanup;
}
gnutls_psk_set_client_credentials(creds->data.client,
username, &key, GNUTLS_PSK_KEY_HEX);
}
rv = 0;
cleanup:
g_free(key.data);
return rv;
}
static void
qcrypto_tls_creds_psk_unload(QCryptoTLSCredsPSK *creds)
{
if (creds->parent_obj.endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
if (creds->data.client) {
gnutls_psk_free_client_credentials(creds->data.client);
creds->data.client = NULL;
}
} else {
if (creds->data.server) {
gnutls_psk_free_server_credentials(creds->data.server);
creds->data.server = NULL;
}
}
if (creds->parent_obj.dh_params) {
gnutls_dh_params_deinit(creds->parent_obj.dh_params);
creds->parent_obj.dh_params = NULL;
}
}
#else /* ! CONFIG_GNUTLS */
static void
qcrypto_tls_creds_psk_load(QCryptoTLSCredsPSK *creds G_GNUC_UNUSED,
Error **errp)
{
error_setg(errp, "TLS credentials support requires GNUTLS");
}
static void
qcrypto_tls_creds_psk_unload(QCryptoTLSCredsPSK *creds G_GNUC_UNUSED)
{
/* nada */
}
#endif /* ! CONFIG_GNUTLS */
static void
qcrypto_tls_creds_psk_complete(UserCreatable *uc, Error **errp)
{
QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(uc);
qcrypto_tls_creds_psk_load(creds, errp);
}
#ifdef CONFIG_GNUTLS
static bool
qcrypto_tls_creds_psk_prop_get_loaded(Object *obj,
Error **errp G_GNUC_UNUSED)
{
QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(obj);
if (creds->parent_obj.endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
return creds->data.server != NULL;
} else {
return creds->data.client != NULL;
}
}
#else /* ! CONFIG_GNUTLS */
static bool
qcrypto_tls_creds_psk_prop_get_loaded(Object *obj G_GNUC_UNUSED,
Error **errp G_GNUC_UNUSED)
{
return false;
}
#endif /* ! CONFIG_GNUTLS */
static void
qcrypto_tls_creds_psk_finalize(Object *obj)
{
QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(obj);
qcrypto_tls_creds_psk_unload(creds);
}
static void
qcrypto_tls_creds_psk_prop_set_username(Object *obj,
const char *value,
Error **errp G_GNUC_UNUSED)
{
QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(obj);
creds->username = g_strdup(value);
}
static char *
qcrypto_tls_creds_psk_prop_get_username(Object *obj,
Error **errp G_GNUC_UNUSED)
{
QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(obj);
return g_strdup(creds->username);
}
static void
qcrypto_tls_creds_psk_class_init(ObjectClass *oc, void *data)
{
UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
ucc->complete = qcrypto_tls_creds_psk_complete;
object_class_property_add_bool(oc, "loaded",
qcrypto_tls_creds_psk_prop_get_loaded,
NULL);
object_class_property_add_str(oc, "username",
qcrypto_tls_creds_psk_prop_get_username,
qom: Drop parameter @errp of object_property_add() & friends The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]
2020-05-05 17:29:22 +02:00
qcrypto_tls_creds_psk_prop_set_username);
}
static const TypeInfo qcrypto_tls_creds_psk_info = {
.parent = TYPE_QCRYPTO_TLS_CREDS,
.name = TYPE_QCRYPTO_TLS_CREDS_PSK,
.instance_size = sizeof(QCryptoTLSCredsPSK),
.instance_finalize = qcrypto_tls_creds_psk_finalize,
.class_size = sizeof(QCryptoTLSCredsPSKClass),
.class_init = qcrypto_tls_creds_psk_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_USER_CREATABLE },
{ }
}
};
static void
qcrypto_tls_creds_psk_register_types(void)
{
type_register_static(&qcrypto_tls_creds_psk_info);
}
type_init(qcrypto_tls_creds_psk_register_types);