client: Initial support for TLS in the client

Use GNUtls because it is GPL compatible and instead of mbedTLS seems
to have a working non-blocking I/O integration. GNUtls has various
issues that could not be resolved easily:

* Pick spdy as sub protocol
* gmt_time not randomized
* private key loaded to RAM (but not verified)

This is the beginning and not the end. Client support might need more
work with actual tls verification. Maybe more manual x509 cert
verification is needed and maybe client certs don't work at all. I try
to ignore renegotiation as I threw away the key.

Reload x509 creds and keys as they might have changed from one
connection to another.

Change-Id: I9128e14084da1fc2705f858393f98b8133996172
This commit is contained in:
Holger Hans Peter Freyther 2016-08-25 23:07:44 +02:00
parent c1c194393b
commit c266796caa
12 changed files with 678 additions and 7 deletions

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@ -2,6 +2,7 @@ language: c
os: os:
- linux - linux
sudo: required sudo: required
dist: trusty
addons: addons:
apt: apt:
packages: packages:
@ -18,6 +19,7 @@ addons:
- libpcsclite-dev - libpcsclite-dev
- libpcap-dev - libpcap-dev
- libzmq3-dev - libzmq3-dev
- libgnutls28-dev
script: script:
- contrib/travis.sh - contrib/travis.sh

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@ -63,6 +63,7 @@ PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 0.3.2)
PKG_CHECK_MODULES(LIBOSMOGSM, libosmogsm >= 0.3.2) PKG_CHECK_MODULES(LIBOSMOGSM, libosmogsm >= 0.3.2)
PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 0.3.0) PKG_CHECK_MODULES(LIBOSMOVTY, libosmovty >= 0.3.0)
PKG_CHECK_MODULES(LIBZMQ, libzmq >= 3.2.2) PKG_CHECK_MODULES(LIBZMQ, libzmq >= 3.2.2)
PKG_CHECK_MODULES(LIBGNUTLS, gnutls)
# Coverage build taken from WebKit's configure.in # Coverage build taken from WebKit's configure.in

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@ -1 +1 @@
noinst_HEADERS = common.h osmo_pcap_client.h osmo_pcap_server.h wireformat.h noinst_HEADERS = common.h osmo_pcap_client.h osmo_pcap_server.h wireformat.h osmo_tls.h

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@ -34,6 +34,7 @@ enum {
DCLIENT, DCLIENT,
DSERVER, DSERVER,
DVTY, DVTY,
DTLS,
Debug_LastEntry, Debug_LastEntry,
}; };

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@ -20,6 +20,8 @@
* *
*/ */
#include "osmo_tls.h"
#include <inttypes.h> #include <inttypes.h>
#include <pcap.h> #include <pcap.h>
@ -64,6 +66,20 @@ struct osmo_pcap_client {
struct osmo_wqueue wqueue; struct osmo_wqueue wqueue;
struct osmo_timer_list timer; struct osmo_timer_list timer;
/* TLS handling */
bool tls_on;
bool tls_verify;
char *tls_hostname;
char *tls_capath;
char *tls_priority;
char *tls_client_cert;
char *tls_client_key;
unsigned tls_log_level;
struct osmo_tls_session tls_session;
/* statistics */ /* statistics */
struct rate_ctr_group *ctrg; struct rate_ctr_group *ctrg;
}; };

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@ -0,0 +1,65 @@
/*
* osmo-pcap TLS code
*
* (C) 2016 by Holger Hans Peter Freyther <holger@moiji-mobile.com>
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#pragma once
#include <gnutls/gnutls.h>
#include <gnutls/abstract.h>
#include <stdbool.h>
struct osmo_fd;
struct osmo_wqueue;
struct osmo_pcap_client;
struct osmo_tls_session {
bool in_use;
bool need_handshake;
bool need_resend;
gnutls_session_t session;
/* any credentials */
bool anon_alloc;
gnutls_anon_client_credentials_t anon_cred;
/* a x509 cert credential */
bool cert_alloc;
gnutls_certificate_credentials_t cert_cred;
/* the private certificate */
bool pcert_alloc;
gnutls_pcert_st pcert;
/* the private key in _RAM_ */
bool privk_alloc;
gnutls_privkey_t privk;
struct osmo_wqueue *wqueue;
void (*error)(struct osmo_tls_session *session);
void (*handshake_done)(struct osmo_tls_session *session);
};
void osmo_tls_init(void);
bool osmo_tls_init_client_session(struct osmo_pcap_client *client);
void osmo_tls_release(struct osmo_tls_session *);
int osmo_tls_client_bfd_cb(struct osmo_fd *fd, unsigned int what);

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@ -1,12 +1,13 @@
AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)/ AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)/
AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(PCAP_CFLAGS) AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(PCAP_CFLAGS) $(LIBGNUTLS_CFLAGS)
bin_PROGRAMS = osmo_pcap_client osmo_pcap_server bin_PROGRAMS = osmo_pcap_client osmo_pcap_server
osmo_pcap_client_SOURCES = osmo_client_main.c osmo_common.c \ osmo_pcap_client_SOURCES = osmo_client_main.c osmo_common.c \
osmo_client_core.c osmo_client_vty.c \ osmo_client_core.c osmo_client_vty.c \
osmo_client_network.c osmo_client_network.c osmo_tls.c
osmo_pcap_client_LDADD = $(PCAP_LIBS) $(LIBOSMOCORE_LIBS) $(LIBOSMOVTY_LIBS) $(LIBOSMOGSM_LIBS) osmo_pcap_client_LDADD = $(PCAP_LIBS) $(LIBOSMOCORE_LIBS) $(LIBOSMOVTY_LIBS) \
$(LIBOSMOGSM_LIBS) $(LIBGNUTLS_LIBS)
osmo_pcap_server_SOURCES = osmo_server_main.c osmo_common.c \ osmo_pcap_server_SOURCES = osmo_server_main.c osmo_common.c \
osmo_server_vty.c osmo_server_network.c osmo_server_vty.c osmo_server_network.c

View File

@ -22,6 +22,7 @@
#include <osmo-pcap/common.h> #include <osmo-pcap/common.h>
#include <osmo-pcap/osmo_pcap_client.h> #include <osmo-pcap/osmo_pcap_client.h>
#include <osmo-pcap/osmo_tls.h>
#include <osmocom/core/application.h> #include <osmocom/core/application.h>
#include <osmocom/core/rate_ctr.h> #include <osmocom/core/rate_ctr.h>
@ -203,6 +204,8 @@ int main(int argc, char **argv)
signal(SIGUSR1, &signal_handler); signal(SIGUSR1, &signal_handler);
osmo_init_ignore_signals(); osmo_init_ignore_signals();
osmo_tls_init();
rc = telnet_init(tall_bsc_ctx, NULL, 4240); rc = telnet_init(tall_bsc_ctx, NULL, 4240);
if (rc < 0) { if (rc < 0) {
LOGP(DCLIENT, LOGL_ERROR, "Failed to bind telnet interface\n"); LOGP(DCLIENT, LOGL_ERROR, "Failed to bind telnet interface\n");
@ -215,6 +218,7 @@ int main(int argc, char **argv)
exit(1); exit(1);
} }
pcap_client->fd.fd = -1; pcap_client->fd.fd = -1;
pcap_client->tls_verify = true;
vty_client_init(pcap_client); vty_client_init(pcap_client);
/* initialize the queue */ /* initialize the queue */

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@ -47,6 +47,7 @@ static void _osmo_client_connect(void *_data)
static void lost_connection(struct osmo_pcap_client *client) static void lost_connection(struct osmo_pcap_client *client)
{ {
if (client->wqueue.bfd.fd >= 0) { if (client->wqueue.bfd.fd >= 0) {
osmo_tls_release(&client->tls_session);
osmo_fd_unregister(&client->wqueue.bfd); osmo_fd_unregister(&client->wqueue.bfd);
close(client->wqueue.bfd.fd); close(client->wqueue.bfd.fd);
client->wqueue.bfd.fd = -1; client->wqueue.bfd.fd = -1;
@ -100,6 +101,22 @@ static int write_cb(struct osmo_fd *fd, struct msgb *msg)
return 0; return 0;
} }
static void handshake_done_cb(struct osmo_tls_session *session)
{
struct osmo_pcap_client *client;
client = container_of(session, struct osmo_pcap_client, tls_session);
osmo_client_send_link(client);
}
static void tls_error_cb(struct osmo_tls_session *session)
{
struct osmo_pcap_client *client;
client = container_of(session, struct osmo_pcap_client, tls_session);
lost_connection(client);
}
void osmo_client_send_data(struct osmo_pcap_client *client, void osmo_client_send_data(struct osmo_pcap_client *client,
struct pcap_pkthdr *in_hdr, const uint8_t *data) struct pcap_pkthdr *in_hdr, const uint8_t *data)
{ {
@ -177,7 +194,6 @@ void osmo_client_connect(struct osmo_pcap_client *client)
client->wqueue.read_cb = read_cb; client->wqueue.read_cb = read_cb;
client->wqueue.write_cb = write_cb; client->wqueue.write_cb = write_cb;
client->wqueue.bfd.when = BSC_FD_READ; client->wqueue.bfd.when = BSC_FD_READ;
client->wqueue.bfd.data = client;
osmo_wqueue_clear(&client->wqueue); osmo_wqueue_clear(&client->wqueue);
fd = osmo_sock_init(AF_INET, SOCK_STREAM, IPPROTO_TCP, fd = osmo_sock_init(AF_INET, SOCK_STREAM, IPPROTO_TCP,
@ -199,7 +215,23 @@ void osmo_client_connect(struct osmo_pcap_client *client)
} }
rate_ctr_inc(&client->ctrg->ctr[CLIENT_CTR_CONNECT]); rate_ctr_inc(&client->ctrg->ctr[CLIENT_CTR_CONNECT]);
osmo_client_send_link(client);
/*
* The write queue needs to work differently for GNUtls. Before we can
* send data we will need to complete handshake.
*/
if (client->tls_on) {
if (!osmo_tls_init_client_session(client)) {
lost_connection(client);
return;
}
client->tls_session.handshake_done = handshake_done_cb;
client->tls_session.error = tls_error_cb;
} else {
client->wqueue.bfd.cb = osmo_wqueue_bfd_cb;
client->wqueue.bfd.data = client;
osmo_client_send_link(client);
}
} }
void osmo_client_reconnect(struct osmo_pcap_client *client) void osmo_client_reconnect(struct osmo_pcap_client *client)

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@ -1,7 +1,7 @@
/* /*
* osmo-pcap-client code * osmo-pcap-client code
* *
* (C) 2011 by Holger Hans Peter Freyther <zecke@selfish.org> * (C) 2011-2016 by Holger Hans Peter Freyther <holger@moiji-mobile.com>
* (C) 2011 by On-Waves * (C) 2011 by On-Waves
* All Rights Reserved * All Rights Reserved
* *
@ -62,6 +62,26 @@ static int config_write_client(struct vty *vty)
if (pcap_client->gprs_filtering) if (pcap_client->gprs_filtering)
vty_out(vty, " pcap add-filter gprs%s", VTY_NEWLINE); vty_out(vty, " pcap add-filter gprs%s", VTY_NEWLINE);
if (pcap_client->tls_on) {
vty_out(vty, " enable tls%s", VTY_NEWLINE);
vty_out(vty, " tls hostname %s%s", pcap_client->tls_hostname, VTY_NEWLINE);
vty_out(vty, " %stls verify-cert%s",
pcap_client->tls_verify ? "" : "no ", VTY_NEWLINE);
if (pcap_client->tls_capath)
vty_out(vty, " tls capath %s%s", pcap_client->tls_capath, VTY_NEWLINE);
if (pcap_client->tls_client_cert)
vty_out(vty, " tls client-cert %s%s",
pcap_client->tls_client_cert, VTY_NEWLINE);
if (pcap_client->tls_client_key)
vty_out(vty, " tls client-key %s%s",
pcap_client->tls_client_key, VTY_NEWLINE);
if (pcap_client->tls_priority)
vty_out(vty, " tls priority %s%s",
pcap_client->tls_priority, VTY_NEWLINE);
vty_out(vty, " tls log-level %d%s",
pcap_client->tls_log_level, VTY_NEWLINE);
}
if (pcap_client->srv_ip) if (pcap_client->srv_ip)
vty_out(vty, " server ip %s%s", vty_out(vty, " server ip %s%s",
pcap_client->srv_ip, VTY_NEWLINE); pcap_client->srv_ip, VTY_NEWLINE);
@ -131,6 +151,162 @@ DEFUN(cfg_client_loop,
return CMD_SUCCESS; return CMD_SUCCESS;
} }
#define TLS_STR "Transport Layer Security\n"
DEFUN(cfg_enable_tls,
cfg_enable_tls_cmd,
"enable tls",
"Enable\n" "Transport Layer Security\n")
{
if (!pcap_client->tls_on) {
if (pcap_client->wqueue.bfd.fd >= 0)
osmo_client_reconnect(pcap_client);
}
pcap_client->tls_on = true;
return CMD_SUCCESS;
}
DEFUN(cfg_disable_tls,
cfg_disable_tls_cmd,
"disable tls",
"Disable\n" "Transport Layer Security\n")
{
if (pcap_client->tls_on)
osmo_client_reconnect(pcap_client);
pcap_client->tls_on = false;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_hostname,
cfg_tls_hostname_cmd,
"tls hostname NAME",
TLS_STR "hostname for certificate validation\n" "name\n")
{
talloc_free(pcap_client->tls_hostname);
pcap_client->tls_hostname = talloc_strdup(pcap_client, argv[0]);
return CMD_SUCCESS;
}
DEFUN(cfg_no_tls_hostname,
cfg_no_tls_hostname_cmd,
"no tls hostname",
NO_STR TLS_STR "hostname for certificate validation\n")
{
talloc_free(pcap_client->tls_hostname);
pcap_client->tls_hostname = NULL;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_verify,
cfg_tls_verify_cmd,
"tls verify-cert",
TLS_STR "Verify certificates\n")
{
pcap_client->tls_verify = true;
return CMD_SUCCESS;
}
DEFUN(cfg_no_tls_verify,
cfg_no_tls_verify_cmd,
"no tls verify-cert",
NO_STR TLS_STR "Verify certificates\n")
{
pcap_client->tls_verify = false;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_capath,
cfg_tls_capath_cmd,
"tls capath .PATH",
TLS_STR "Trusted root certificates\n" "Filename\n")
{
talloc_free(pcap_client->tls_capath);
pcap_client->tls_capath = talloc_strdup(pcap_client, argv[0]);
return CMD_SUCCESS;
}
DEFUN(cfg_no_tls_capath,
cfg_no_tls_capath_cmd,
"no tls capath",
NO_STR TLS_STR "Trusted root certificates\n")
{
talloc_free(pcap_client->tls_capath);
pcap_client->tls_capath = NULL;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_client_cert,
cfg_tls_client_cert_cmd,
"tls client-cert .PATH",
TLS_STR "Client certificate for authentication\n" "Filename\n")
{
talloc_free(pcap_client->tls_client_cert);
pcap_client->tls_client_cert = talloc_strdup(pcap_client, argv[0]);
return CMD_SUCCESS;
}
DEFUN(cfg_no_tls_client_cert,
cfg_no_tls_client_cert_cmd,
"no tls client-cert",
NO_STR TLS_STR "Client certificate for authentication\n")
{
talloc_free(pcap_client->tls_client_cert);
pcap_client->tls_client_cert = NULL;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_client_key,
cfg_tls_client_key_cmd,
"tls client-key .PATH",
TLS_STR "Client private key\n" "Filename\n")
{
talloc_free(pcap_client->tls_client_key);
pcap_client->tls_client_key = talloc_strdup(pcap_client, argv[0]);
return CMD_SUCCESS;
}
DEFUN(cfg_no_tls_client_key,
cfg_no_tls_client_key_cmd,
"no tls client-key",
NO_STR TLS_STR "Client private key\n")
{
talloc_free(pcap_client->tls_client_key);
pcap_client->tls_client_key = NULL;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_priority,
cfg_tls_priority_cmd,
"tls priority STR",
TLS_STR "Priority string for GNUtls\n" "Priority string\n")
{
talloc_free(pcap_client->tls_priority);
pcap_client->tls_priority = talloc_strdup(pcap_client, argv[0]);
return CMD_SUCCESS;
}
DEFUN(cfg_no_tls_priority,
cfg_no_tls_priority_cmd,
"no tls priority",
NO_STR TLS_STR "Priority string for GNUtls\n")
{
talloc_free(pcap_client->tls_priority);
pcap_client->tls_priority = NULL;
return CMD_SUCCESS;
}
DEFUN(cfg_tls_log_level,
cfg_tls_log_level_cmd,
"tls log-level <0-255>",
TLS_STR "Log-level\n" "GNUtls debug level\n")
{
pcap_client->tls_log_level = atoi(argv[0]);
return CMD_SUCCESS;
}
DEFUN(cfg_server_ip, DEFUN(cfg_server_ip,
cfg_server_ip_cmd, cfg_server_ip_cmd,
"server ip A.B.C.D", "server ip A.B.C.D",
@ -164,6 +340,22 @@ int vty_client_init(struct osmo_pcap_client *pcap)
install_element(CLIENT_NODE, &cfg_server_ip_cmd); install_element(CLIENT_NODE, &cfg_server_ip_cmd);
install_element(CLIENT_NODE, &cfg_server_port_cmd); install_element(CLIENT_NODE, &cfg_server_port_cmd);
install_element(CLIENT_NODE, &cfg_enable_tls_cmd);
install_element(CLIENT_NODE, &cfg_disable_tls_cmd);
install_element(CLIENT_NODE, &cfg_tls_hostname_cmd);
install_element(CLIENT_NODE, &cfg_no_tls_hostname_cmd);
install_element(CLIENT_NODE, &cfg_tls_verify_cmd);
install_element(CLIENT_NODE, &cfg_no_tls_verify_cmd);
install_element(CLIENT_NODE, &cfg_tls_capath_cmd);
install_element(CLIENT_NODE, &cfg_no_tls_capath_cmd);
install_element(CLIENT_NODE, &cfg_tls_client_cert_cmd);
install_element(CLIENT_NODE, &cfg_no_tls_client_cert_cmd);
install_element(CLIENT_NODE, &cfg_tls_client_key_cmd);
install_element(CLIENT_NODE, &cfg_no_tls_client_key_cmd);
install_element(CLIENT_NODE, &cfg_tls_priority_cmd);
install_element(CLIENT_NODE, &cfg_no_tls_priority_cmd);
install_element(CLIENT_NODE, &cfg_tls_log_level_cmd);
install_element(CLIENT_NODE, &cfg_client_add_gprs_cmd); install_element(CLIENT_NODE, &cfg_client_add_gprs_cmd);
install_element(CLIENT_NODE, &cfg_client_del_gprs_cmd); install_element(CLIENT_NODE, &cfg_client_del_gprs_cmd);

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@ -49,6 +49,12 @@ static const struct log_info_cat default_categories[] = {
.color = "\033[1;34m", .color = "\033[1;34m",
.enabled = 1, .loglevel = LOGL_NOTICE, .enabled = 1, .loglevel = LOGL_NOTICE,
}, },
[DTLS] = {
.name = "DTLS",
.description = "TLS code",
.color = "\033[1;34m",
.enabled = 1, .loglevel = LOGL_NOTICE,
},
}; };
const struct log_info log_info = { const struct log_info log_info = {

351
src/osmo_tls.c Normal file
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@ -0,0 +1,351 @@
/*
* osmo-pcap TLS code
*
* (C) 2016 by Holger Hans Peter Freyther <holger@moiji-mobile.com>
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <osmo-pcap/osmo_tls.h>
#include <osmo-pcap/osmo_pcap_client.h>
#include <osmo-pcap/common.h>
#include <osmocom/core/write_queue.h>
#include <osmocom/core/talloc.h>
#include <string.h>
#define CHECK_RC(rc, str) \
if (rc != 0) { \
LOGP(DTLS, LOGL_ERROR, "%s with rc=%d\n", str, rc); \
exit(1); \
}
static int cert_callback(gnutls_session_t tls_session,
const gnutls_datum_t * req_ca_rdn, int nreqs,
const gnutls_pk_algorithm_t * sign_algos,
int sign_algos_length, gnutls_pcert_st ** pcert,
unsigned int *pcert_length, gnutls_privkey_t * pkey)
{
struct osmo_tls_session *sess = gnutls_session_get_ptr(tls_session);
gnutls_certificate_type_t type;
LOGP(DTLS, LOGL_DEBUG, "cert callback from server\n");
type = gnutls_certificate_type_get(tls_session);
if (type != GNUTLS_CRT_X509)
return -1;
*pcert_length = 1;
*pcert = &sess->pcert;
*pkey = sess->privk;
return 0;
}
static void tls_log_func(int level, const char *str)
{
LOGP(DTLS, LOGL_DEBUG, "GNUtls: |<%d>| %s", level, str);
}
static int verify_cert_cb(gnutls_session_t session)
{
const char *hostname;
unsigned int status;
int ret;
hostname = gnutls_session_get_ptr(session);
ret = gnutls_certificate_verify_peers3(session,
hostname, &status);
if (ret != 0)
return GNUTLS_E_CERTIFICATE_ERROR;
if (status != 0)
return GNUTLS_E_CERTIFICATE_ERROR;
return 0;
}
static void release_keys(struct osmo_tls_session *sess)
{
if (sess->pcert_alloc) {
gnutls_pcert_deinit(&sess->pcert);
sess->pcert_alloc = false;
}
if (sess->privk_alloc) {
gnutls_privkey_deinit(sess->privk);
sess->privk_alloc = false;
}
}
void osmo_tls_init(void)
{
int rc;
rc = gnutls_global_init();
CHECK_RC(rc, "init failed");
gnutls_global_set_log_function(tls_log_func);
}
static int need_handshake(struct osmo_tls_session *tls_session)
{
int rc;
rc = gnutls_handshake(tls_session->session);
if (rc == 0) {
/* handshake is done. start writing if we are allowed to */
LOGP(DTLS, LOGL_NOTICE, "TLS handshake done.\n");
if (!llist_empty(&tls_session->wqueue->msg_queue))
tls_session->wqueue->bfd.when = BSC_FD_WRITE | BSC_FD_READ;
else
tls_session->wqueue->bfd.when = BSC_FD_READ;
tls_session->need_handshake = false;
release_keys(tls_session);
tls_session->handshake_done(tls_session);
} else if (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED) {
LOGP(DTLS, LOGL_DEBUG, "rc=%d will wait for writable again.\n", rc);
} else if (gnutls_error_is_fatal(rc)) {
/* it failed for good.. */
LOGP(DTLS, LOGL_ERROR, "handshake failed rc=%d str=%s\n",
rc, gnutls_strerror(rc));
tls_session->wqueue->bfd.when = 0;
tls_session->error(tls_session);
}
return 0;
}
static int tls_read(struct osmo_tls_session *sess)
{
char buf[1024];
int rc;
memset(buf, 0, sizeof(buf));
rc = gnutls_record_recv(sess->session, buf, sizeof(buf) - 1);
return rc;
}
static int tls_write(struct osmo_tls_session *sess)
{
int rc;
sess->wqueue->bfd.when &= ~BSC_FD_WRITE;
if (llist_empty(&sess->wqueue->msg_queue))
return 0;
if (sess->need_resend) {
rc = gnutls_record_send(sess->session, NULL, 0);
} else {
struct msgb *msg;
msg = (struct msgb *) sess->wqueue->msg_queue.next;
rc = gnutls_record_send(sess->session, msg->data, msg->len);
}
if (rc > 0) {
sess->wqueue->current_length -= 1;
sess->need_resend = false;
struct msgb *msg = msgb_dequeue(&sess->wqueue->msg_queue);
msgb_free(msg);
} else if (rc == GNUTLS_E_INTERRUPTED || rc == GNUTLS_E_AGAIN) {
sess->need_resend = true;
} else if (gnutls_error_is_fatal(rc)) {
return rc;
}
if (sess->need_resend || !llist_empty(&sess->wqueue->msg_queue))
sess->wqueue->bfd.when |= BSC_FD_WRITE;
return rc;
}
int osmo_tls_client_bfd_cb(struct osmo_fd *fd, unsigned what)
{
struct osmo_tls_session *sess = fd->data;
if (sess->need_handshake)
return need_handshake(sess);
if (what & BSC_FD_READ) {
int rc = tls_read(sess);
if (rc <= 0) {
sess->error(sess);
return rc;
}
}
if (what & BSC_FD_WRITE) {
int rc = tls_write(sess);
if (rc < 0) {
sess->error(sess);
return rc;
}
}
return 0;
}
static int load_keys(struct osmo_pcap_client *client)
{
struct osmo_tls_session *sess = &client->tls_session;
gnutls_datum_t data;
int rc;
if (!client->tls_client_cert || !client->tls_client_key) {
LOGP(DTLS, LOGL_DEBUG, "Skipping x509 client cert %p %p\n",
client->tls_client_cert, client->tls_client_key);
return 0;
}
rc = gnutls_load_file(client->tls_client_cert, &data);
if (rc < 0) {
LOGP(DTLS, LOGL_ERROR, "Failed to load file=%s rc=%d\n",
client->tls_client_cert, rc);
return -1;
}
rc = gnutls_pcert_import_x509_raw(&sess->pcert, &data, GNUTLS_X509_FMT_PEM, 0);
gnutls_free(data.data);
if (rc < 0) {
LOGP(DTLS, LOGL_ERROR, "Failed to import file=%s rc=%d\n",
client->tls_client_cert, rc);
return -1;
}
sess->pcert_alloc = true;
/* copied to RAM.. nothing we can do about it */
rc = gnutls_load_file(client->tls_client_key, &data);
if (rc < 0) {
LOGP(DTLS, LOGL_ERROR, "Failed to load file=%s rc=%d\n",
client->tls_client_key, rc);
return -1;
}
gnutls_privkey_init(&sess->privk);
rc = gnutls_privkey_import_x509_raw(sess->privk, &data, GNUTLS_X509_FMT_PEM, NULL, 0);
gnutls_free(data.data);
if (rc < 0) {
LOGP(DTLS, LOGL_ERROR, "Failed to load file=%s rc=%d\n",
client->tls_client_key, rc);
release_keys(sess);
return -1;
}
sess->privk_alloc = true;
return 0;
}
bool osmo_tls_init_client_session(struct osmo_pcap_client *client)
{
struct osmo_tls_session *sess = &client->tls_session;
struct osmo_wqueue *wq = &client->wqueue;
unsigned int status;
int rc;
gnutls_global_set_log_level(client->tls_log_level);
memset(sess, 0, sizeof(*sess));
sess->in_use = sess->anon_alloc = sess->cert_alloc = false;
rc = gnutls_init(&sess->session, GNUTLS_CLIENT | GNUTLS_NONBLOCK);
if (rc != GNUTLS_E_SUCCESS) {
LOGP(DTLS, LOGL_ERROR, "gnutls_init failed with rc=%d\n", rc);
return false;
}
gnutls_session_set_ptr(sess->session, sess);
sess->in_use = true;
/* use default or string */
if (client->tls_priority) {
const char *err;
rc = gnutls_priority_set_direct(sess->session, client->tls_priority, &err);
} else {
rc = gnutls_set_default_priority(sess->session);
}
if (rc != GNUTLS_E_SUCCESS) {
LOGP(DTLS, LOGL_ERROR, "def prio failed with rc=%d\n", rc);
osmo_tls_release(sess);
return false;
}
/* allow username/password operation */
rc = gnutls_anon_allocate_client_credentials(&sess->anon_cred);
if (rc != GNUTLS_E_SUCCESS) {
LOGP(DTLS, LOGL_ERROR, "Failed to allocate anon cred rc=%d\n", rc);
osmo_tls_release(sess);
return false;
}
sess->anon_alloc = true;
/* x509 certificate handling */
rc = gnutls_certificate_allocate_credentials(&sess->cert_cred);
if (rc != GNUTLS_E_SUCCESS) {
LOGP(DTLS, LOGL_ERROR, "Failed to allocate x509 cred rc=%d\n", rc);
osmo_tls_release(sess);
return false;
}
sess->cert_alloc = true;
/* set the credentials now */
gnutls_credentials_set(sess->session, GNUTLS_CRD_ANON, sess->anon_cred);
gnutls_credentials_set(sess->session, GNUTLS_CRD_CERTIFICATE, sess->cert_cred);
if (client->tls_capath) {
rc = gnutls_certificate_set_x509_trust_file(
sess->cert_cred, client->tls_capath, GNUTLS_X509_FMT_PEM);
if (rc != GNUTLS_E_SUCCESS) {
LOGP(DTLS, LOGL_ERROR, "Failed to load capath from path=%s rc=%d\n",
client->tls_capath, rc);
osmo_tls_release(sess);
return false;
}
}
if (load_keys(client) != 0) {
osmo_tls_release(sess);
return false;
}
gnutls_certificate_set_retrieve_function2(sess->cert_cred, cert_callback);
/* set the hostname if we have one */
if (client->tls_hostname)
gnutls_server_name_set(sess->session, GNUTLS_NAME_DNS,
client->tls_hostname, strlen(client->tls_hostname));
/* do the verification */
if (client->tls_verify) {
gnutls_certificate_set_verify_function(sess->cert_cred, verify_cert_cb);
gnutls_certificate_verify_peers3(sess->session, client->tls_hostname, &status);
} else
LOGP(DTLS, LOGL_NOTICE, "Not going to validate certs as configured\n");
gnutls_transport_set_int(sess->session, wq->bfd.fd);
gnutls_handshake_set_timeout(sess->session,
GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
wq->bfd.cb = osmo_tls_client_bfd_cb;
wq->bfd.data = sess;
wq->bfd.when = BSC_FD_READ | BSC_FD_WRITE;
sess->need_handshake = true;
sess->wqueue = wq;
return true;
}
void osmo_tls_release(struct osmo_tls_session *session)
{
if (!session->in_use)
return;
gnutls_deinit(session->session);
release_keys(session);
if (session->anon_alloc)
gnutls_anon_free_client_credentials(session->anon_cred);
if (session->cert_alloc)
gnutls_certificate_free_credentials(session->cert_cred);
session->in_use = false;
}