crypto/tlscredspsk.c - qemu - Git at Google

 /*
  * 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 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

 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)
 {
     char *pskfile = NULL, *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);
     g_free(pskfile);
     g_free(dhparams);
     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_prop_set_loaded(Object *obj,
                                       bool value,
                                       Error **errp)
 {
     QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(obj);

     if (value) {
         qcrypto_tls_creds_psk_load(creds, errp);
     } else {
         qcrypto_tls_creds_psk_unload(creds);
     }
 }


 #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_complete(UserCreatable *uc, Error **errp)
 {
     object_property_set_bool(OBJECT(uc), true, "loaded", errp);
 }


 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,
                                    qcrypto_tls_creds_psk_prop_set_loaded,
                                    NULL);
     object_class_property_add_str(oc, "username",
                                   qcrypto_tls_creds_psk_prop_get_username,
                                   qcrypto_tls_creds_psk_prop_set_username,
                                   NULL);
 }


 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);
	/*
	* 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 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

	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)
	{
	char pskfile = NULL, 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);
	g_free(pskfile);
	g_free(dhparams);
	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_prop_set_loaded(Object *obj,
	bool value,
	Error **errp)
	{
	QCryptoTLSCredsPSK *creds = QCRYPTO_TLS_CREDS_PSK(obj);

	if (value) {
	qcrypto_tls_creds_psk_load(creds, errp);
	} else {
	qcrypto_tls_creds_psk_unload(creds);
	}
	}


	#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_complete(UserCreatable uc, Error *errp)
	{
	object_property_set_bool(OBJECT(uc), true, "loaded", errp);
	}


	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,
	qcrypto_tls_creds_psk_prop_set_loaded,
	NULL);
	object_class_property_add_str(oc, "username",
	qcrypto_tls_creds_psk_prop_get_username,
	qcrypto_tls_creds_psk_prop_set_username,
	NULL);
	}


	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);