/**
* @brief Free an event context.
*
* @param event The ssh_event object to free.
* Note: you have to manually remove sessions and socket
* fds before freeing the event object.
*
*/
void ssh_event_free(ssh_event event) {
int used, i;
ssh_poll_handle p;
if(event == NULL) {
return;
}
if(event->ctx != NULL) {
used = event->ctx->polls_used;
for(i = 0; i < used; i++) {
p = event->ctx->pollptrs[i];
if(p->session != NULL) {
ssh_poll_ctx_remove(event->ctx, p);
ssh_poll_ctx_add(p->session->default_poll_ctx, p);
p->session = NULL;
used = 0;
}
}
ssh_poll_ctx_free(event->ctx);
}
#ifdef WITH_SERVER
if(event->sessions != NULL) {
ssh_list_free(event->sessions);
}
#endif
free(event);
}
/**
* @brief Free an event context.
*
* @param event The ssh_event object to free.
* Note: you have to manually remove sessions and socket
* fds before freeing the event object.
*
*/
void ssh_event_free(ssh_event event) {
if(event == NULL) {
return;
}
if(event->ctx != NULL) {
ssh_poll_ctx_free(event->ctx);
}
#ifdef WITH_SERVER
if(event->sessions != NULL) {
ssh_list_free(event->sessions);
}
#endif
free(event);
}
/**
* @brief Disconnect from a session (client or server).
* The session can then be reused to open a new session.
*
* @param[in] session The SSH session to use.
*/
void ssh_disconnect(ssh_session session) {
ssh_string str = NULL;
struct ssh_iterator *it;
if (session == NULL) {
return;
}
if (session->socket != NULL && ssh_socket_is_open(session->socket)) {
if (buffer_add_u8(session->out_buffer, SSH2_MSG_DISCONNECT) < 0) {
goto error;
}
if (buffer_add_u32(session->out_buffer,
htonl(SSH2_DISCONNECT_BY_APPLICATION)) < 0) {
goto error;
}
str = ssh_string_from_char("Bye Bye");
if (str == NULL) {
goto error;
}
if (buffer_add_ssh_string(session->out_buffer,str) < 0) {
ssh_string_free(str);
goto error;
}
ssh_string_free(str);
packet_send(session);
ssh_socket_close(session->socket);
}
error:
session->alive = 0;
if (session->socket != NULL){
ssh_socket_reset(session->socket);
}
session->opts.fd = SSH_INVALID_SOCKET;
session->session_state=SSH_SESSION_STATE_DISCONNECTED;
while ((it=ssh_list_get_iterator(session->channels)) != NULL) {
ssh_channel_do_free(ssh_iterator_value(ssh_channel,it));
ssh_list_remove(session->channels, it);
}
if(session->current_crypto){
crypto_free(session->current_crypto);
session->current_crypto=NULL;
}
if (session->in_buffer) {
ssh_buffer_reinit(session->in_buffer);
}
if (session->out_buffer) {
ssh_buffer_reinit(session->out_buffer);
}
if (session->in_hashbuf) {
ssh_buffer_reinit(session->in_hashbuf);
}
if (session->out_hashbuf) {
ssh_buffer_reinit(session->out_hashbuf);
}
session->auth_methods = 0;
SAFE_FREE(session->serverbanner);
SAFE_FREE(session->clientbanner);
if(session->ssh_message_list){
ssh_message msg;
while((msg=ssh_list_pop_head(ssh_message ,session->ssh_message_list))
!= NULL){
ssh_message_free(msg);
}
ssh_list_free(session->ssh_message_list);
session->ssh_message_list=NULL;
}
if (session->packet_callbacks){
ssh_list_free(session->packet_callbacks);
session->packet_callbacks=NULL;
}
}
/**
* @brief Deallocate a SSH session handle.
*
* @param[in] session The SSH session to free.
*
* @see ssh_disconnect()
* @see ssh_new()
*/
void ssh_free(ssh_session session) {
int i;
struct ssh_iterator *it;
if (session == NULL) {
return;
}
/*
* Delete all channels
*
* This needs the first thing we clean up cause if there is still an open
* channel we call ssh_channel_close() first. So we need a working socket
* and poll context for it.
*/
for (it = ssh_list_get_iterator(session->channels);
it != NULL;
it = ssh_list_get_iterator(session->channels)) {
ssh_channel_do_free(ssh_iterator_value(ssh_channel,it));
ssh_list_remove(session->channels, it);
}
ssh_list_free(session->channels);
session->channels = NULL;
#ifdef WITH_PCAP
if (session->pcap_ctx) {
ssh_pcap_context_free(session->pcap_ctx);
session->pcap_ctx = NULL;
}
#endif
ssh_socket_free(session->socket);
session->socket = NULL;
if (session->default_poll_ctx) {
ssh_poll_ctx_free(session->default_poll_ctx);
}
ssh_buffer_free(session->in_buffer);
ssh_buffer_free(session->out_buffer);
session->in_buffer = session->out_buffer = NULL;
if (session->in_hashbuf != NULL) {
ssh_buffer_free(session->in_hashbuf);
}
if (session->out_hashbuf != NULL) {
ssh_buffer_free(session->out_hashbuf);
}
crypto_free(session->current_crypto);
crypto_free(session->next_crypto);
#ifndef _WIN32
agent_free(session->agent);
#endif /* _WIN32 */
ssh_key_free(session->srv.dsa_key);
ssh_key_free(session->srv.rsa_key);
if (session->ssh_message_list) {
ssh_message msg;
for (msg = ssh_list_pop_head(ssh_message, session->ssh_message_list);
msg != NULL;
msg = ssh_list_pop_head(ssh_message, session->ssh_message_list)) {
ssh_message_free(msg);
}
ssh_list_free(session->ssh_message_list);
}
if (session->packet_callbacks) {
ssh_list_free(session->packet_callbacks);
}
/* options */
if (session->opts.identity) {
char *id;
for (id = ssh_list_pop_head(char *, session->opts.identity);
id != NULL;
id = ssh_list_pop_head(char *, session->opts.identity)) {
SAFE_FREE(id);
}
ssh_list_free(session->opts.identity);
}
static void torture_knownhosts_precheck(void **state)
{
struct torture_state *s = *state;
ssh_session session = s->ssh.session;
struct ssh_list *algo_list = NULL;
struct ssh_iterator *it = NULL;
size_t algo_count;
const char *algo = NULL;
char known_hosts_file[1024] = {0};
FILE *file;
int rc;
snprintf(known_hosts_file,
sizeof(known_hosts_file),
"%s/%s",
s->socket_dir,
TORTURE_KNOWN_HOSTS_FILE);
file = fopen(known_hosts_file, "w");
assert_non_null(file);
fprintf(file,
"127.0.0.10 %s\n",
torture_get_testkey_pub(SSH_KEYTYPE_RSA));
fprintf(file,
"127.0.0.10 %s\n",
torture_get_testkey_pub(SSH_KEYTYPE_ED25519));
fprintf(file,
"127.0.0.10 %s\n",
torture_get_testkey_pub(SSH_KEYTYPE_ECDSA_P521));
fclose(file);
rc = ssh_options_set(session, SSH_OPTIONS_KNOWNHOSTS, known_hosts_file);
assert_ssh_return_code(session, rc);
algo_list = ssh_known_hosts_get_algorithms(session);
assert_non_null(algo_list);
algo_count = ssh_list_count(algo_list);
assert_int_equal(algo_count, 3);
it = ssh_list_get_iterator(algo_list);
assert_non_null(it);
algo = ssh_iterator_value(const char *, it);
assert_string_equal(algo, "ssh-rsa");
ssh_list_remove(algo_list, it);
it = ssh_list_get_iterator(algo_list);
assert_non_null(it);
algo = ssh_iterator_value(const char *, it);
assert_string_equal(algo, "ssh-ed25519");
ssh_list_remove(algo_list, it);
it = ssh_list_get_iterator(algo_list);
assert_non_null(it);
algo = ssh_iterator_value(const char *, it);
assert_string_equal(algo, "ecdsa-sha2-nistp521");
ssh_list_free(algo_list);
}
/**
* @brief Disconnect from a session (client or server).
* The session can then be reused to open a new session.
*
* @param[in] session The SSH session to use.
*/
void ssh_disconnect(ssh_session session) {
ssh_string str = NULL;
int i;
if (session == NULL) {
return;
}
enter_function();
if (ssh_socket_is_open(session->socket)) {
if (buffer_add_u8(session->out_buffer, SSH2_MSG_DISCONNECT) < 0) {
goto error;
}
if (buffer_add_u32(session->out_buffer,
htonl(SSH2_DISCONNECT_BY_APPLICATION)) < 0) {
goto error;
}
str = ssh_string_from_char("Bye Bye");
if (str == NULL) {
goto error;
}
if (buffer_add_ssh_string(session->out_buffer,str) < 0) {
ssh_string_free(str);
goto error;
}
ssh_string_free(str);
packet_send(session);
ssh_socket_close(session->socket);
}
error:
session->alive = 0;
if(session->socket){
ssh_socket_reset(session->socket);
}
session->fd = SSH_INVALID_SOCKET;
session->session_state=SSH_SESSION_STATE_DISCONNECTED;
while (session->channels) {
ssh_channel_free(session->channels);
}
if(session->current_crypto){
crypto_free(session->current_crypto);
session->current_crypto=NULL;
}
if(session->in_buffer)
buffer_reinit(session->in_buffer);
if(session->out_buffer)
buffer_reinit(session->out_buffer);
if(session->in_hashbuf)
buffer_reinit(session->in_hashbuf);
if(session->out_hashbuf)
buffer_reinit(session->out_hashbuf);
session->auth_methods = 0;
SAFE_FREE(session->serverbanner);
SAFE_FREE(session->clientbanner);
if (session->client_kex.methods) {
for (i = 0; i < 10; i++) {
SAFE_FREE(session->client_kex.methods[i]);
}
}
if (session->server_kex.methods) {
for (i = 0; i < 10; i++) {
SAFE_FREE(session->server_kex.methods[i]);
}
}
SAFE_FREE(session->client_kex.methods);
SAFE_FREE(session->server_kex.methods);
if(session->ssh_message_list){
ssh_message msg;
while((msg=ssh_list_pop_head(ssh_message ,session->ssh_message_list))
!= NULL){
ssh_message_free(msg);
}
ssh_list_free(session->ssh_message_list);
session->ssh_message_list=NULL;
}
if (session->packet_callbacks){
ssh_list_free(session->packet_callbacks);
session->packet_callbacks=NULL;
}
leave_function();
}
/**
* @brief Disconnect from a session (client or server).
* The session can then be reused to open a new session.
*
* @param[in] session The SSH session to use.
*/
void ssh_disconnect(ssh_session session) {
struct ssh_iterator *it;
int rc;
if (session == NULL) {
return;
}
if (session->socket != NULL && ssh_socket_is_open(session->socket)) {
rc = ssh_buffer_pack(session->out_buffer,
"bdss",
SSH2_MSG_DISCONNECT,
SSH2_DISCONNECT_BY_APPLICATION,
"Bye Bye",
""); /* language tag */
if (rc != SSH_OK){
ssh_set_error_oom(session);
goto error;
}
ssh_packet_send(session);
ssh_socket_close(session->socket);
}
error:
session->recv_seq = 0;
session->send_seq = 0;
session->alive = 0;
if (session->socket != NULL){
ssh_socket_reset(session->socket);
}
session->opts.fd = SSH_INVALID_SOCKET;
session->session_state=SSH_SESSION_STATE_DISCONNECTED;
while ((it=ssh_list_get_iterator(session->channels)) != NULL) {
ssh_channel_do_free(ssh_iterator_value(ssh_channel,it));
ssh_list_remove(session->channels, it);
}
if(session->current_crypto){
crypto_free(session->current_crypto);
session->current_crypto=NULL;
}
if (session->next_crypto) {
crypto_free(session->next_crypto);
session->next_crypto = crypto_new();
if (session->next_crypto == NULL) {
ssh_set_error_oom(session);
}
}
if (session->in_buffer) {
ssh_buffer_reinit(session->in_buffer);
}
if (session->out_buffer) {
ssh_buffer_reinit(session->out_buffer);
}
if (session->in_hashbuf) {
ssh_buffer_reinit(session->in_hashbuf);
}
if (session->out_hashbuf) {
ssh_buffer_reinit(session->out_hashbuf);
}
session->auth.supported_methods = 0;
SAFE_FREE(session->serverbanner);
SAFE_FREE(session->clientbanner);
if(session->ssh_message_list){
ssh_message msg;
while((msg=ssh_list_pop_head(ssh_message ,session->ssh_message_list))
!= NULL){
ssh_message_free(msg);
}
ssh_list_free(session->ssh_message_list);
session->ssh_message_list=NULL;
}
if (session->packet_callbacks){
ssh_list_free(session->packet_callbacks);
session->packet_callbacks=NULL;
}
}
static void torture_callbacks_execute_list(void **state){
struct ssh_list *list = ssh_list_new();
int v = 0, w = 0;
struct ssh_channel_callbacks_struct c1 = {
.channel_eof_function = cb1,
.userdata = &v
};
struct ssh_channel_callbacks_struct c2 = {
.channel_exit_status_function = cb2,
.userdata = &v
};
struct ssh_channel_callbacks_struct c3 = {
.channel_eof_function = cb1,
.channel_exit_status_function = cb2,
.userdata = &w
};
(void)state;
ssh_callbacks_init(&c1);
ssh_callbacks_init(&c2);
ssh_callbacks_init(&c3);
ssh_list_append(list, &c1);
ssh_callbacks_execute_list(list,
ssh_channel_callbacks,
channel_eof_function,
NULL,
NULL);
assert_int_equal(v, 1);
v = 0;
ssh_list_append(list, &c2);
ssh_callbacks_execute_list(list,
ssh_channel_callbacks,
channel_eof_function,
NULL,
NULL);
assert_int_equal(v, 1);
ssh_callbacks_execute_list(list,
ssh_channel_callbacks,
channel_exit_status_function,
NULL,
NULL,
0);
assert_int_equal(v, 11);
v = 0;
w = 0;
ssh_list_append(list, &c3);
ssh_callbacks_execute_list(list,
ssh_channel_callbacks,
channel_eof_function,
NULL,
NULL);
assert_int_equal(v, 1);
assert_int_equal(w, 1);
ssh_callbacks_execute_list(list,
ssh_channel_callbacks,
channel_exit_status_function,
NULL,
NULL,
0);
assert_int_equal(v, 11);
assert_int_equal(w, 11);
ssh_list_free(list);
}
/**
* @internal
* @brief selects the hostkey mechanisms to be chosen for the key exchange,
* as some hostkey mechanisms may be present in known_hosts file and preferred
* @returns a cstring containing a comma-separated list of hostkey methods.
* NULL if no method matches
*/
char *ssh_client_select_hostkeys(ssh_session session)
{
char methods_buffer[128]={0};
char tail_buffer[128]={0};
char *new_hostkeys = NULL;
static const char *preferred_hostkeys[] = {
"ssh-ed25519",
"ecdsa-sha2-nistp521",
"ecdsa-sha2-nistp384",
"ecdsa-sha2-nistp256",
"rsa-sha2-512",
"rsa-sha2-256",
"ssh-rsa",
#ifdef HAVE_DSA
"ssh-dss",
#endif
NULL
};
struct ssh_list *algo_list = NULL;
struct ssh_iterator *it = NULL;
size_t algo_count;
int needcomma = 0;
size_t i, len;
algo_list = ssh_known_hosts_get_algorithms(session);
if (algo_list == NULL) {
return NULL;
}
algo_count = ssh_list_count(algo_list);
if (algo_count == 0) {
ssh_list_free(algo_list);
return NULL;
}
for (i = 0; preferred_hostkeys[i] != NULL; ++i) {
bool found = false;
/* This is a signature type: We list also the SHA2 extensions */
enum ssh_keytypes_e base_preferred =
ssh_key_type_from_signature_name(preferred_hostkeys[i]);
for (it = ssh_list_get_iterator(algo_list);
it != NULL;
it = it->next) {
const char *algo = ssh_iterator_value(const char *, it);
/* This is always key type so we do not have to care for the
* SHA2 extension */
enum ssh_keytypes_e base_algo = ssh_key_type_from_name(algo);
if (base_preferred == base_algo) {
/* Matching the keys already verified it is a known type */
if (needcomma) {
strncat(methods_buffer,
",",
sizeof(methods_buffer) - strlen(methods_buffer) - 1);
}
strncat(methods_buffer,
preferred_hostkeys[i],
sizeof(methods_buffer) - strlen(methods_buffer) - 1);
needcomma = 1;
found = true;
}
}
/* Collect the rest of the algorithms in other buffer, that will
* follow the preferred buffer. This will signalize all the algorithms
* we are willing to accept.
*/
if (!found) {
snprintf(tail_buffer + strlen(tail_buffer),
sizeof(tail_buffer) - strlen(tail_buffer),
",%s", preferred_hostkeys[i]);
}
}
ssh_list_free(algo_list);
if (strlen(methods_buffer) == 0) {
SSH_LOG(SSH_LOG_DEBUG,
"No supported kex method for existing key in known_hosts file");
return NULL;
}
/* Append the supported list to the preferred.
* The length is maximum 128 + 128 + 1, which will not overflow
*/
len = strlen(methods_buffer) + strlen(tail_buffer) + 1;
new_hostkeys = malloc(len);
if (new_hostkeys == NULL) {
ssh_set_error_oom(session);
return NULL;
}
snprintf(new_hostkeys, len,
"%s%s", methods_buffer, tail_buffer);
SSH_LOG(SSH_LOG_DEBUG,
"Changing host key method to \"%s\"",
new_hostkeys);
return new_hostkeys;
}