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tls: move gnutls code into tls_gnutls.c

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Currently nts_ke_session.c directly calls into gnutls.
This patch moves the calls to gnutls into tls_gnutls.c with an API
defined in tls.h. This way it becomes possible to use different TLS
implementations in future patches.

Signed-off-by: Anthony Brandon <anthony@amarulasolutions.com>
This commit is contained in:
Anthony Brandon
2025-05-30 16:47:21 +02:00
committed by Miroslav Lichvar
parent 52cce3dea8
commit 3e32e7e694
4 changed files with 575 additions and 250 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
configure vendored
View File

@@ -1011,7 +1011,7 @@ if [ $feat_nts = "1" ] && [ $try_gnutls = "1" ]; then
fi
if grep '#define HAVE_SIV' config.h > /dev/null; then
EXTRA_OBJECTS="$EXTRA_OBJECTS nts_ke_client.o nts_ke_server.o nts_ke_session.o"
EXTRA_OBJECTS="$EXTRA_OBJECTS nts_ke_client.o nts_ke_server.o nts_ke_session.o tls_gnutls.o"
EXTRA_OBJECTS="$EXTRA_OBJECTS nts_ntp_auth.o nts_ntp_client.o nts_ntp_server.o"
LIBS="$LIBS $test_link"
MYCPPFLAGS="$MYCPPFLAGS $test_cflags"

317
nts_ke_session.c
View File

@@ -37,11 +37,9 @@
#include "siv.h"
#include "socket.h"
#include "sched.h"
#include "tls.h"
#include "util.h"
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#define INVALID_SOCK_FD (-8)
struct RecordHeader {
@@ -75,7 +73,7 @@ struct NKSN_Instance_Record {
KeState state;
int sock_fd;
char *label;
gnutls_session_t tls_session;
TLS_Instance tls_session;
SCH_TimeoutID timeout_id;
int retry_factor;
@@ -85,8 +83,6 @@ struct NKSN_Instance_Record {
/* ================================================== */
static gnutls_priority_t priority_cache;
static int credentials_counter = 0;
static int clock_updates = 0;
@@ -206,71 +202,6 @@ check_message_format(struct Message *message, int eof)
/* ================================================== */
static gnutls_session_t
create_tls_session(int server_mode, int sock_fd, const char *server_name,
gnutls_certificate_credentials_t credentials,
gnutls_priority_t priority)
{
unsigned char alpn_name[sizeof (NKE_ALPN_NAME)];
gnutls_session_t session;
gnutls_datum_t alpn;
unsigned int flags;
int r;
r = gnutls_init(&session, GNUTLS_NONBLOCK | GNUTLS_NO_TICKETS |
(server_mode ? GNUTLS_SERVER : GNUTLS_CLIENT));
if (r < 0) {
LOG(LOGS_ERR, "Could not %s TLS session : %s", "create", gnutls_strerror(r));
return NULL;
}
if (!server_mode) {
assert(server_name);
if (!UTI_IsStringIP(server_name)) {
r = gnutls_server_name_set(session, GNUTLS_NAME_DNS, server_name, strlen(server_name));
if (r < 0)
goto error;
}
flags = 0;
if (clock_updates < CNF_GetNoCertTimeCheck()) {
flags |= GNUTLS_VERIFY_DISABLE_TIME_CHECKS | GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS;
DEBUG_LOG("Disabled time checks");
}
gnutls_session_set_verify_cert(session, server_name, flags);
}
r = gnutls_priority_set(session, priority);
if (r < 0)
goto error;
r = gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, credentials);
if (r < 0)
goto error;
memcpy(alpn_name, NKE_ALPN_NAME, sizeof (alpn_name));
alpn.data = alpn_name;
alpn.size = sizeof (alpn_name) - 1;
r = gnutls_alpn_set_protocols(session, &alpn, 1, 0);
if (r < 0)
goto error;
gnutls_transport_set_int(session, sock_fd);
return session;
error:
LOG(LOGS_ERR, "Could not %s TLS session : %s", "set", gnutls_strerror(r));
gnutls_deinit(session);
return NULL;
}
/* ================================================== */
static void
stop_session(NKSN_Instance inst)
{
@@ -286,7 +217,7 @@ stop_session(NKSN_Instance inst)
Free(inst->label);
inst->label = NULL;
gnutls_deinit(inst->tls_session);
TLS_DestroyInstance(inst->tls_session);
inst->tls_session = NULL;
SCH_RemoveTimeout(inst->timeout_id);
@@ -308,21 +239,6 @@ session_timeout(void *arg)
/* ================================================== */
static int
check_alpn(NKSN_Instance inst)
{
gnutls_datum_t alpn;
if (gnutls_alpn_get_selected_protocol(inst->tls_session, &alpn) < 0 ||
alpn.size != sizeof (NKE_ALPN_NAME) - 1 ||
memcmp(alpn.data, NKE_ALPN_NAME, sizeof (NKE_ALPN_NAME) - 1) != 0)
return 0;
return 1;
}
/* ================================================== */
static void
set_input_output(NKSN_Instance inst, int output)
{
@@ -364,6 +280,7 @@ static int
handle_event(NKSN_Instance inst, int event)
{
struct Message *message = &inst->message;
TLS_Status s;
int r;
DEBUG_LOG("Session event %d fd=%d state=%d", event, inst->sock_fd, (int)inst->state);
@@ -390,56 +307,28 @@ handle_event(NKSN_Instance inst, int event)
return 0;
case KE_HANDSHAKE:
r = gnutls_handshake(inst->tls_session);
if (r < 0) {
if (gnutls_error_is_fatal(r)) {
gnutls_datum_t cert_error;
/* Get a description of verification errors */
if (r != GNUTLS_E_CERTIFICATE_VERIFICATION_ERROR ||
gnutls_certificate_verification_status_print(
gnutls_session_get_verify_cert_status(inst->tls_session),
gnutls_certificate_type_get(inst->tls_session), &cert_error, 0) < 0)
cert_error.data = NULL;
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
"TLS handshake with %s failed : %s%s%s", inst->label, gnutls_strerror(r),
cert_error.data ? " " : "", cert_error.data ? (const char *)cert_error.data : "");
if (cert_error.data)
gnutls_free(cert_error.data);
s = TLS_DoHandshake(inst->tls_session);
switch (s) {
case TLS_SUCCESS:
break;
case TLS_AGAIN_OUTPUT:
case TLS_AGAIN_INPUT:
set_input_output(inst, s == TLS_AGAIN_OUTPUT);
return 0;
default:
stop_session(inst);
/* Increase the retry interval if the handshake did not fail due
to the other end closing the connection */
if (r != GNUTLS_E_PULL_ERROR && r != GNUTLS_E_PREMATURE_TERMINATION)
if (s != TLS_CLOSED)
inst->retry_factor = NKE_RETRY_FACTOR2_TLS;
return 0;
}
/* Disable output when the handshake is trying to receive data */
set_input_output(inst, gnutls_record_get_direction(inst->tls_session));
return 0;
}
inst->retry_factor = NKE_RETRY_FACTOR2_TLS;
if (DEBUG) {
char *description = gnutls_session_get_desc(inst->tls_session);
DEBUG_LOG("Handshake with %s completed %s",
inst->label, description ? description : "");
gnutls_free(description);
}
if (!check_alpn(inst)) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR, "NTS-KE not supported by %s", inst->label);
stop_session(inst);
return 0;
}
/* Client will send a request to the server */
change_state(inst, inst->server ? KE_RECEIVE : KE_SEND);
return 0;
@@ -448,16 +337,17 @@ handle_event(NKSN_Instance inst, int event)
assert(inst->new_message && message->complete);
assert(message->length <= sizeof (message->data) && message->length > message->sent);
r = gnutls_record_send(inst->tls_session, &message->data[message->sent],
message->length - message->sent);
s = TLS_Send(inst->tls_session, &message->data[message->sent],
message->length - message->sent, &r);
if (r < 0) {
if (gnutls_error_is_fatal(r)) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
"Could not send NTS-KE message to %s : %s", inst->label, gnutls_strerror(r));
switch (s) {
case TLS_SUCCESS:
break;
case TLS_AGAIN_OUTPUT:
return 0;
default:
stop_session(inst);
}
return 0;
return 0;
}
DEBUG_LOG("Sent %d bytes to %s", r, inst->label);
@@ -480,26 +370,24 @@ handle_event(NKSN_Instance inst, int event)
return 0;
}
r = gnutls_record_recv(inst->tls_session, &message->data[message->length],
sizeof (message->data) - message->length);
s = TLS_Receive(inst->tls_session, &message->data[message->length],
sizeof (message->data) - message->length, &r);
if (r < 0) {
/* Handle a renegotiation request on both client and server as
a protocol error */
if (gnutls_error_is_fatal(r) || r == GNUTLS_E_REHANDSHAKE) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
"Could not receive NTS-KE message from %s : %s",
inst->label, gnutls_strerror(r));
switch (s) {
case TLS_SUCCESS:
break;
case TLS_AGAIN_INPUT:
return 0;
default:
stop_session(inst);
}
return 0;
return 0;
}
DEBUG_LOG("Received %d bytes from %s", r, inst->label);
message->length += r;
} while (gnutls_record_check_pending(inst->tls_session) > 0);
} while (TLS_CheckPending(inst->tls_session));
if (!check_message_format(message, r == 0)) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
@@ -519,18 +407,18 @@ handle_event(NKSN_Instance inst, int event)
return 1;
case KE_SHUTDOWN:
r = gnutls_bye(inst->tls_session, GNUTLS_SHUT_RDWR);
s = TLS_Shutdown(inst->tls_session);
if (r < 0) {
if (gnutls_error_is_fatal(r)) {
DEBUG_LOG("Shutdown with %s failed : %s", inst->label, gnutls_strerror(r));
switch (s) {
case TLS_SUCCESS:
break;
case TLS_AGAIN_OUTPUT:
case TLS_AGAIN_INPUT:
set_input_output(inst, s == TLS_AGAIN_OUTPUT);
return 0;
default:
stop_session(inst);
return 0;
}
/* Disable output when the TLS shutdown is trying to receive data */
set_input_output(inst, gnutls_record_get_direction(inst->tls_session));
return 0;
}
SCK_ShutdownConnection(inst->sock_fd);
@@ -592,36 +480,18 @@ handle_step(struct timespec *raw, struct timespec *cooked, double dfreq,
/* ================================================== */
static int gnutls_initialised = 0;
static int tls_initialised = 0;
static int
init_gnutls(void)
init_tls(void)
{
int r;
if (gnutls_initialised)
if (tls_initialised)
return 1;
r = gnutls_global_init();
if (r < 0)
LOG_FATAL("Could not initialise %s : %s", "gnutls", gnutls_strerror(r));
/* Prepare a priority cache for server and client NTS-KE sessions
(the NTS specification requires TLS1.3 or later) */
r = gnutls_priority_init2(&priority_cache,
"-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-TLS1.2:-VERS-DTLS-ALL",
NULL, GNUTLS_PRIORITY_INIT_DEF_APPEND);
if (r < 0) {
LOG(LOGS_ERR, "Could not initialise %s : %s",
"priority cache for TLS", gnutls_strerror(r));
gnutls_global_deinit();
if (!TLS_Initialise(&get_time))
return 0;
}
/* Use our clock instead of the system clock in certificate verification */
gnutls_global_set_time_function(get_time);
gnutls_initialised = 1;
tls_initialised = 1;
DEBUG_LOG("Initialised");
LCL_AddParameterChangeHandler(handle_step, NULL);
@@ -632,16 +502,15 @@ init_gnutls(void)
/* ================================================== */
static void
deinit_gnutls(void)
deinit_tls(void)
{
if (!gnutls_initialised || credentials_counter > 0)
if (!tls_initialised || credentials_counter > 0)
return;
LCL_RemoveParameterChangeHandler(handle_step, NULL);
gnutls_priority_deinit(priority_cache);
gnutls_global_deinit();
gnutls_initialised = 0;
TLS_Finalise();
tls_initialised = 0;
DEBUG_LOG("Deinitialised");
}
@@ -652,67 +521,21 @@ create_credentials(const char **certs, const char **keys, int n_certs_keys,
const char **trusted_certs, uint32_t *trusted_certs_ids,
int n_trusted_certs, uint32_t trusted_cert_set)
{
gnutls_certificate_credentials_t credentials = NULL;
int i, r;
TLS_Credentials credentials;
if (!init_gnutls())
if (!init_tls())
return NULL;
r = gnutls_certificate_allocate_credentials(&credentials);
if (r < 0)
goto error;
if (certs && keys) {
BRIEF_ASSERT(!trusted_certs && !trusted_certs_ids);
for (i = 0; i < n_certs_keys; i++) {
if (!UTI_CheckFilePermissions(keys[i], 0771))
;
r = gnutls_certificate_set_x509_key_file(credentials, certs[i], keys[i],
GNUTLS_X509_FMT_PEM);
if (r < 0)
goto error;
}
} else {
BRIEF_ASSERT(!certs && !keys && n_certs_keys <= 0);
if (trusted_cert_set == 0 && !CNF_GetNoSystemCert()) {
r = gnutls_certificate_set_x509_system_trust(credentials);
if (r < 0)
goto error;
}
if (trusted_certs && trusted_certs_ids) {
for (i = 0; i < n_trusted_certs; i++) {
struct stat buf;
if (trusted_certs_ids[i] != trusted_cert_set)
continue;
if (stat(trusted_certs[i], &buf) == 0 && S_ISDIR(buf.st_mode))
r = gnutls_certificate_set_x509_trust_dir(credentials, trusted_certs[i],
GNUTLS_X509_FMT_PEM);
else
r = gnutls_certificate_set_x509_trust_file(credentials, trusted_certs[i],
GNUTLS_X509_FMT_PEM);
if (r < 0)
goto error;
DEBUG_LOG("Added %d trusted certs from %s", r, trusted_certs[i]);
}
}
credentials = TLS_CreateCredentials(certs, keys, n_certs_keys, trusted_certs,
trusted_certs_ids, n_trusted_certs, trusted_cert_set);
if (!credentials) {
deinit_tls();
return NULL;
}
credentials_counter++;
return (NKSN_Credentials)credentials;
error:
LOG(LOGS_ERR, "Could not set credentials : %s", gnutls_strerror(r));
if (credentials)
gnutls_certificate_free_credentials(credentials);
deinit_gnutls();
return NULL;
return credentials;
}
/* ================================================== */
@@ -737,9 +560,9 @@ NKSN_CreateClientCertCredentials(const char **certs, uint32_t *ids,
void
NKSN_DestroyCertCredentials(NKSN_Credentials credentials)
{
gnutls_certificate_free_credentials((gnutls_certificate_credentials_t)credentials);
TLS_DestroyCredentials(credentials);
credentials_counter--;
deinit_gnutls();
deinit_tls();
}
/* ================================================== */
@@ -789,9 +612,9 @@ NKSN_StartSession(NKSN_Instance inst, int sock_fd, const char *label,
{
assert(inst->state == KE_STOPPED);
inst->tls_session = create_tls_session(inst->server, sock_fd, inst->server_name,
(gnutls_certificate_credentials_t)credentials,
priority_cache);
inst->tls_session = TLS_CreateInstance(inst->server, sock_fd, inst->server_name,
NKE_ALPN_NAME, credentials,
clock_updates < CNF_GetNoCertTimeCheck());
if (!inst->tls_session)
return 0;
@@ -899,19 +722,15 @@ NKSN_GetKeys(NKSN_Instance inst, SIV_Algorithm algorithm, SIV_Algorithm exporter
context.algorithm = htons(exporter_algorithm);
context.is_s2c = 0;
if (gnutls_prf_rfc5705(inst->tls_session,
sizeof (NKE_EXPORTER_LABEL) - 1, NKE_EXPORTER_LABEL,
sizeof (context) - 1, (char *)&context,
length, (char *)c2s->key) < 0) {
if (!TLS_ExportKey(inst->tls_session, sizeof (NKE_EXPORTER_LABEL) - 1, NKE_EXPORTER_LABEL,
sizeof (context) - 1, &context, length, c2s->key)) {
DEBUG_LOG("Could not export key");
return 0;
}
context.is_s2c = 1;
if (gnutls_prf_rfc5705(inst->tls_session,
sizeof (NKE_EXPORTER_LABEL) - 1, NKE_EXPORTER_LABEL,
sizeof (context) - 1, (char *)&context,
length, (char *)s2c->key) < 0) {
if (!TLS_ExportKey(inst->tls_session, sizeof (NKE_EXPORTER_LABEL) - 1, NKE_EXPORTER_LABEL,
sizeof (context) - 1, &context, length, s2c->key)) {
DEBUG_LOG("Could not export key");
return 0;
}

93
tls.h Normal file
View File

@@ -0,0 +1,93 @@
/*
chronyd/chronyc - Programs for keeping computer clocks accurate.
**********************************************************************
* Copyright (C) Anthony Brandon 2025
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
**********************************************************************
=======================================================================
Header file for the TLS session
*/
#ifndef GOT_TLS_H
#define GOT_TLS_H
struct TLS_Instance_Record;
typedef struct TLS_Instance_Record *TLS_Instance;
typedef void *TLS_Credentials;
typedef enum {
/* TLS operation succeeded */
TLS_SUCCESS,
/* TLS operation failed.
No more operations should be called and the session should be destroyed. */
TLS_FAILED,
/* TLS session closed by other end */
TLS_CLOSED,
/* The last TLS operation should be called again when input is ready */
TLS_AGAIN_INPUT,
/* The last TLS operation should be called again when output is ready */
TLS_AGAIN_OUTPUT,
} TLS_Status;
/* Initialize TLS */
extern int TLS_Initialise(time_t (*get_time)(time_t *t));
/* Deinitialize TLS */
extern void TLS_Finalise(void);
/* Create new TLS credentials instance */
extern TLS_Credentials TLS_CreateCredentials(const char **certs, const char **keys,
int n_certs_keys, const char **trusted_certs,
uint32_t * trusted_certs_ids, int n_trusted_certs,
uint32_t trusted_cert_set);
/* Destroy TLS credentials instance */
extern void TLS_DestroyCredentials(TLS_Credentials credentials);
/* Create new TLS session instance */
extern TLS_Instance TLS_CreateInstance(int server_mode, int sock_fd, const char *server_name,
const char *alpn_name, TLS_Credentials credentials,
int disable_time_checks);
/* Destroy TLS instance */
extern void TLS_DestroyInstance(TLS_Instance inst);
/* Perform TLS handshake */
extern TLS_Status TLS_DoHandshake(TLS_Instance inst);
/* Send data over TLS */
extern TLS_Status TLS_Send(TLS_Instance inst, const void *data, int length, int *sent);
/* Receive data over TLS */
extern TLS_Status TLS_Receive(TLS_Instance inst, void *data, int length, int *received);
/* Check if there is data pending to read */
extern int TLS_CheckPending(TLS_Instance inst);
/* Perform TLS shutdown */
extern TLS_Status TLS_Shutdown(TLS_Instance inst);
/* Export key from TLS instance */
extern int TLS_ExportKey(TLS_Instance inst, int label_length, const char *label,
int context_length, const void *context, int key_length,
unsigned char *key);
#endif

413
tls_gnutls.c Normal file
View File

@@ -0,0 +1,413 @@
/*
chronyd/chronyc - Programs for keeping computer clocks accurate.
**********************************************************************
* Copyright (C) Miroslav Lichvar 2020-2021
* Copyright (C) Anthony Brandon 2025
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
**********************************************************************
=======================================================================
Routines implementing TLS session handling using the gnutls library.
*/
#include "config.h"
#include "sysincl.h"
#include "tls.h"
#include "conf.h"
#include "logging.h"
#include "memory.h"
#include "util.h"
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
struct TLS_Instance_Record {
gnutls_session_t session;
int server;
char *server_name;
char *alpn_name;
};
/* ================================================== */
static gnutls_priority_t priority_cache;
/* ================================================== */
int
TLS_Initialise(time_t (*get_time)(time_t *t))
{
int r = gnutls_global_init();
if (r < 0)
LOG_FATAL("Could not initialise %s : %s", "gnutls", gnutls_strerror(r));
/* Prepare a priority cache for server and client NTS-KE sessions
(the NTS specification requires TLS1.3 or later) */
r = gnutls_priority_init2(&priority_cache,
"-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-TLS1.2:-VERS-DTLS-ALL",
NULL, GNUTLS_PRIORITY_INIT_DEF_APPEND);
if (r < 0) {
LOG(LOGS_ERR, "Could not initialise %s : %s",
"priority cache for TLS", gnutls_strerror(r));
gnutls_global_deinit();
return 0;
}
/* Use our clock instead of the system clock in certificate verification */
gnutls_global_set_time_function(get_time);
return 1;
}
/* ================================================== */
void
TLS_Finalise(void)
{
gnutls_priority_deinit(priority_cache);
gnutls_global_deinit();
}
/* ================================================== */
TLS_Credentials
TLS_CreateCredentials(const char **certs, const char **keys, int n_certs_keys,
const char **trusted_certs, uint32_t *trusted_certs_ids,
int n_trusted_certs, uint32_t trusted_cert_set)
{
gnutls_certificate_credentials_t credentials = NULL;
int i, r;
r = gnutls_certificate_allocate_credentials(&credentials);
if (r < 0)
goto error;
if (certs && keys) {
BRIEF_ASSERT(!trusted_certs && !trusted_certs_ids);
for (i = 0; i < n_certs_keys; i++) {
if (!UTI_CheckFilePermissions(keys[i], 0771))
;
r = gnutls_certificate_set_x509_key_file(credentials, certs[i], keys[i],
GNUTLS_X509_FMT_PEM);
if (r < 0)
goto error;
}
} else {
BRIEF_ASSERT(!certs && !keys && n_certs_keys <= 0);
if (trusted_cert_set == 0 && !CNF_GetNoSystemCert()) {
r = gnutls_certificate_set_x509_system_trust(credentials);
if (r < 0)
goto error;
}
if (trusted_certs && trusted_certs_ids) {
for (i = 0; i < n_trusted_certs; i++) {
struct stat buf;
if (trusted_certs_ids[i] != trusted_cert_set)
continue;
if (stat(trusted_certs[i], &buf) == 0 && S_ISDIR(buf.st_mode))
r = gnutls_certificate_set_x509_trust_dir(credentials, trusted_certs[i],
GNUTLS_X509_FMT_PEM);
else
r = gnutls_certificate_set_x509_trust_file(credentials, trusted_certs[i],
GNUTLS_X509_FMT_PEM);
if (r < 0)
goto error;
DEBUG_LOG("Added %d trusted certs from %s", r, trusted_certs[i]);
}
}
}
return credentials;
error:
LOG(LOGS_ERR, "Could not set credentials : %s", gnutls_strerror(r));
if (credentials)
gnutls_certificate_free_credentials(credentials);
return NULL;
}
/* ================================================== */
void
TLS_DestroyCredentials(TLS_Credentials credentials)
{
gnutls_certificate_free_credentials((gnutls_certificate_credentials_t)credentials);
}
/* ================================================== */
TLS_Instance
TLS_CreateInstance(int server_mode, int sock_fd, const char *server_name,
const char *alpn_name, TLS_Credentials credentials, int disable_time_checks)
{
gnutls_datum_t alpn;
unsigned int flags;
int r;
TLS_Instance inst = MallocNew(struct TLS_Instance_Record);
inst->session = NULL;
inst->server = server_mode;
inst->server_name = server_name ? Strdup(server_name) : NULL;
inst->alpn_name = alpn_name ? Strdup(alpn_name) : NULL;
r = gnutls_init(&inst->session, GNUTLS_NONBLOCK | GNUTLS_NO_TICKETS |
(server_mode ? GNUTLS_SERVER : GNUTLS_CLIENT));
if (r < 0) {
LOG(LOGS_ERR, "Could not %s TLS session : %s", "create", gnutls_strerror(r));
goto error;
}
if (!server_mode) {
assert(server_name);
if (!UTI_IsStringIP(server_name)) {
r = gnutls_server_name_set(inst->session, GNUTLS_NAME_DNS, server_name,
strlen(server_name));
if (r < 0)
goto error;
}
flags = 0;
if (disable_time_checks) {
flags |= GNUTLS_VERIFY_DISABLE_TIME_CHECKS | GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS;
DEBUG_LOG("Disabled time checks");
}
gnutls_session_set_verify_cert(inst->session, server_name, flags);
}
r = gnutls_priority_set(inst->session, priority_cache);
if (r < 0)
goto error;
r = gnutls_credentials_set(inst->session, GNUTLS_CRD_CERTIFICATE, credentials);
if (r < 0)
goto error;
alpn.data = (unsigned char *)inst->alpn_name;
alpn.size = strlen(inst->alpn_name);
r = gnutls_alpn_set_protocols(inst->session, &alpn, 1, 0);
if (r < 0)
goto error;
gnutls_transport_set_int(inst->session, sock_fd);
return inst;
error:
LOG(LOGS_ERR, "Could not %s TLS session : %s", "set", gnutls_strerror(r));
TLS_DestroyInstance(inst);
return NULL;
}
/* ================================================== */
void
TLS_DestroyInstance(TLS_Instance inst)
{
if (inst->session)
gnutls_deinit(inst->session);
if (inst->server_name)
Free(inst->server_name);
if (inst->alpn_name)
Free(inst->alpn_name);
Free(inst);
}
/* ================================================== */
static int
check_alpn(TLS_Instance inst)
{
gnutls_datum_t alpn;
int length = strlen(inst->alpn_name);
if (gnutls_alpn_get_selected_protocol(inst->session, &alpn) < 0 ||
alpn.size != length || memcmp(alpn.data, inst->alpn_name, length) != 0)
return 0;
return 1;
}
/* ================================================== */
TLS_Status
TLS_DoHandshake(TLS_Instance inst)
{
int r = gnutls_handshake(inst->session);
if (r < 0) {
if (gnutls_error_is_fatal(r)) {
gnutls_datum_t cert_error;
/* Get a description of verification errors */
if (r != GNUTLS_E_CERTIFICATE_VERIFICATION_ERROR ||
gnutls_certificate_verification_status_print(
gnutls_session_get_verify_cert_status(inst->session),
gnutls_certificate_type_get(inst->session), &cert_error, 0) < 0)
cert_error.data = NULL;
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
"TLS handshake with %s failed : %s%s%s", inst->server_name, gnutls_strerror(r),
cert_error.data ? " " : "", cert_error.data ? (const char *)cert_error.data : "");
if (cert_error.data)
gnutls_free(cert_error.data);
/* Increase the retry interval if the handshake did not fail due
to the other end closing the connection */
if (r != GNUTLS_E_PULL_ERROR && r != GNUTLS_E_PREMATURE_TERMINATION)
return TLS_FAILED;
return TLS_CLOSED;
}
return gnutls_record_get_direction(inst->session) ? TLS_AGAIN_OUTPUT : TLS_AGAIN_INPUT;
}
if (DEBUG) {
char *description = gnutls_session_get_desc(inst->session);
DEBUG_LOG("Handshake with %s completed %s", inst->server_name,
description ? description : "");
gnutls_free(description);
}
if (!check_alpn(inst)) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR, "NTS-KE not supported by %s", inst->server_name);
return TLS_FAILED;
}
return TLS_SUCCESS;
}
/* ================================================== */
TLS_Status
TLS_Send(TLS_Instance inst, const void *data, int length, int *sent)
{
int r;
if (length < 0)
return TLS_FAILED;
r = gnutls_record_send(inst->session, data, length);
if (r < 0) {
if (gnutls_error_is_fatal(r)) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
"Could not send NTS-KE message to %s : %s", inst->server_name, gnutls_strerror(r));
return TLS_FAILED;
}
return TLS_AGAIN_OUTPUT;
}
*sent = r;
return TLS_SUCCESS;
}
/* ================================================== */
TLS_Status
TLS_Receive(TLS_Instance inst, void *data, int length, int *received)
{
int r;
if (length < 0)
return TLS_FAILED;
r = gnutls_record_recv(inst->session, data, length);
if (r < 0) {
/* Handle a renegotiation request on both client and server as
a protocol error */
if (gnutls_error_is_fatal(r) || r == GNUTLS_E_REHANDSHAKE) {
LOG(inst->server ? LOGS_DEBUG : LOGS_ERR,
"Could not receive NTS-KE message from %s : %s",
inst->server_name, gnutls_strerror(r));
return TLS_FAILED;
}
return TLS_AGAIN_INPUT;
}
*received = r;
return TLS_SUCCESS;
}
/* ================================================== */
int
TLS_CheckPending(TLS_Instance inst)
{
return gnutls_record_check_pending(inst->session) > 0;
}
/* ================================================== */
TLS_Status
TLS_Shutdown(TLS_Instance inst)
{
int r = gnutls_bye(inst->session, GNUTLS_SHUT_RDWR);
if (r < 0) {
if (gnutls_error_is_fatal(r)) {
DEBUG_LOG("Shutdown with %s failed : %s", inst->server_name, gnutls_strerror(r));
return TLS_FAILED;
}
return gnutls_record_get_direction(inst->session) ? TLS_AGAIN_OUTPUT : TLS_AGAIN_INPUT;
}
return TLS_SUCCESS;
}
/* ================================================== */
int
TLS_ExportKey(TLS_Instance inst, int label_length, const char *label, int context_length,
const void *context, int key_length, unsigned char *key)
{
int r;
if (label_length < 0 || context_length < 0 || key_length < 0)
return 0;
r = gnutls_prf_rfc5705(inst->session, label_length, label, context_length, (char *)context,
key_length, (char *)key);
return r >= 0;
}