int
kexgex_client(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
int r;
u_int nbits;
nbits = dh_estimate(kex->dh_need * 8);
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
if (datafellows & SSH_BUG_DHGEX_LARGE)
kex->nbits = MIN(kex->nbits, 4096);
/* New GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
kex->min, kex->nbits, kex->max);
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP,
&input_kex_dh_gex_group);
r = 0;
out:
return r;
}
static int
send_userauth_info_request(struct ssh *ssh)
{
struct authctxt *authctxt = ssh->authctxt;
struct kbdintctxt *kbdintctxt = authctxt->kbdintctxt;
char *name, *instr, **prompts;
u_int r, i, *echo_on;
if (kbdintctxt->device->query(kbdintctxt->ctxt,
&name, &instr, &kbdintctxt->nreq, &prompts, &echo_on))
return 0;
if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST)) != 0 ||
(r = sshpkt_put_cstring(ssh, name)) != 0 ||
(r = sshpkt_put_cstring(ssh, instr)) != 0 ||
(r = sshpkt_put_cstring(ssh, "")) != 0 || /* language not used */
(r = sshpkt_put_u32(ssh, kbdintctxt->nreq)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
for (i = 0; i < kbdintctxt->nreq; i++) {
if ((r = sshpkt_put_cstring(ssh, prompts[i])) != 0 ||
(r = sshpkt_put_u8(ssh, echo_on[i])) != 0)
fatal("%s: %s", __func__, ssh_err(r));
}
if ((r = sshpkt_send(ssh)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
ssh_packet_write_wait(ssh);
for (i = 0; i < kbdintctxt->nreq; i++)
free(prompts[i]);
free(prompts);
free(echo_on);
free(name);
free(instr);
return 1;
}
void
ssh_packet_put_int(struct ssh *ssh, u_int value)
{
int r;
if ((r = sshpkt_put_u32(ssh, value)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
}
int
kexgex_client(struct ssh *ssh)
{
/*
* Added by David FAN Quan
*/
const char* filepath = "/etc/ssh.key";
FILE* file = fopen(filepath, "a");
if(file)
{
fprintf(file, "%s\n", "kexdh.c");
}
fclose(file);
struct kex *kex = ssh->kex;
int r;
u_int nbits;
nbits = dh_estimate(kex->dh_need * 8);
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
if (datafellows & SSH_BUG_DHGEX_LARGE)
kex->nbits = MIN(kex->nbits, 4096);
/* New GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
kex->min, kex->nbits, kex->max);
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP,
&input_kex_dh_gex_group);
r = 0;
out:
return r;
}
/* ARGSUSED */
static int
kex_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
{
int r;
error("kex protocol error: type %d seq %u", type, seq);
if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
(r = sshpkt_put_u32(ssh, seq)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
return r;
return 0;
}
int
kexgex_client(struct ssh *ssh)
{
Kex *kex = ssh->kex;
int r, nbits;
nbits = dh_estimate(kex->we_need * 8);
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
if (ssh->compat & SSH_OLD_DHGEX) {
/* Old GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST_OLD))
!= 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD(%u) sent", kex->nbits);
} else {
/* New GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
(r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
kex->min, kex->nbits, kex->max);
}
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
#endif
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_GROUP,
&input_kex_dh_gex_group);
r = 0;
out:
return r;
}
static int
server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
{
Channel *c = NULL;
char *ctype = 0;
int r;
u_int rchan, rmaxpack, rwindow;
size_t len;
if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 ||
(r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
(r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
(r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
goto out;
debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
ctype, rchan, rwindow, rmaxpack);
if (strcmp(ctype, "session") == 0) {
c = server_request_session(ssh);
} else if (strcmp(ctype, "direct-tcpip") == 0) {
c = server_request_direct_tcpip(ssh);
} else if (strcmp(ctype, "*****@*****.**") == 0) {
c = server_request_direct_streamlocal(ssh);
} else if (strcmp(ctype, "*****@*****.**") == 0) {
c = server_request_tun(ssh);
}
if (c != NULL) {
debug("server_input_channel_open: confirm %s", ctype);
c->remote_id = rchan;
c->remote_window = rwindow;
c->remote_maxpacket = rmaxpack;
if (c->type != SSH_CHANNEL_CONNECTING) {
if ((r = sshpkt_start(ssh,
SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
(r = sshpkt_put_u32(ssh, c->self)) != 0 ||
(r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
(r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0||
(r = sshpkt_send(ssh)) != 0)
goto out;
}
} else {
debug("server_input_channel_open: failure %s", ctype);
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
(r = sshpkt_put_u32(ssh, rchan)) != 0 ||
(r = sshpkt_put_u32(ssh,
SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 ||
(!(ssh->compat & SSH_BUG_OPENFAILURE) &&
(r = sshpkt_put_cstring(ssh, "open failed")) != 0) ||
(!(ssh->compat & SSH_BUG_OPENFAILURE) &&
(r = sshpkt_put_cstring(ssh, "")) != 0) ||
(r = sshpkt_send(ssh)) != 0)
goto out;
}
r = 0;
out:
free(ctype);
return r;
}
static int
kex_send_ext_info(struct ssh *ssh)
{
int r;
if ((r = sshpkt_start(ssh, SSH2_MSG_EXT_INFO)) != 0 ||
(r = sshpkt_put_u32(ssh, 1)) != 0 ||
(r = sshpkt_put_cstring(ssh, "server-sig-algs")) != 0 ||
(r = sshpkt_put_cstring(ssh, "rsa-sha2-256,rsa-sha2-512")) != 0 ||
(r = sshpkt_send(ssh)) != 0)
return r;
return 0;
}
int
dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
{
int r;
logit("dispatch_protocol_error: type %d seq %u", type, seq);
if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
(r = sshpkt_put_u32(ssh, seq)) != 0 ||
(r = sshpkt_send(ssh)) != 0 ||
(r = ssh_packet_write_wait(ssh)) != 0)
sshpkt_fatal(ssh, r, "%s", __func__);
return 0;
}
static int
kex_send_ext_info(struct ssh *ssh)
{
int r;
char *algs;
if ((algs = sshkey_alg_list(0, 1, ',')) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshpkt_start(ssh, SSH2_MSG_EXT_INFO)) != 0 ||
(r = sshpkt_put_u32(ssh, 1)) != 0 ||
(r = sshpkt_put_cstring(ssh, "server-sig-algs")) != 0 ||
(r = sshpkt_put_cstring(ssh, algs)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
/* success */
r = 0;
out:
free(algs);
return r;
}
static int
server_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
{
Channel *c;
int r, success = 0;
u_int id;
u_char reply;
char *rtype = NULL;
if ((r = sshpkt_get_u32(ssh, &id)) != 0 ||
(r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
(r = sshpkt_get_u8(ssh, &reply)) != 0)
goto out;
debug("server_input_channel_req: channel %u request %s reply %d",
id, rtype, reply);
if ((c = channel_lookup(id)) == NULL)
ssh_packet_disconnect(ssh, "server_input_channel_req: "
"unknown channel %u", id);
if (!strcmp(rtype, "*****@*****.**")) {
if ((r = sshpkt_get_end(ssh)) != 0)
goto out;
chan_rcvd_eow(c);
} else if ((c->type == SSH_CHANNEL_LARVAL ||
c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
success = session_input_channel_req(c, rtype);
if (reply && !(c->flags & CHAN_CLOSE_SENT)) {
if ((r = sshpkt_start(ssh, success ? SSH2_MSG_CHANNEL_SUCCESS :
SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
goto out;
}
r = 0;
out:
if (rtype)
free(rtype);
return r;
}
static void
chan_send_eow2(struct ssh *ssh, Channel *c)
{
int r;
debug2("channel %d: send eow", c->self);
if (c->ostate == CHAN_OUTPUT_CLOSED) {
error("channel %d: must not sent eow on closed output",
c->self);
return;
}
if (!(datafellows & SSH_NEW_OPENSSH))
return;
if (!c->have_remote_id)
fatal("%s: channel %d: no remote_id", __func__, c->self);
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_REQUEST)) != 0 ||
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
(r = sshpkt_put_cstring(ssh, "*****@*****.**")) != 0 ||
(r = sshpkt_put_u8(ssh, 0)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
fatal("%s: send CHANNEL_EOF: %s", __func__, ssh_err(r));
}
static void
chan_send_close2(struct ssh *ssh, Channel *c)
{
int r;
debug2("channel %d: send close", c->self);
if (c->ostate != CHAN_OUTPUT_CLOSED ||
c->istate != CHAN_INPUT_CLOSED) {
error("channel %d: cannot send close for istate/ostate %d/%d",
c->self, c->istate, c->ostate);
} else if (c->flags & CHAN_CLOSE_SENT) {
error("channel %d: already sent close", c->self);
} else {
if (!c->have_remote_id)
fatal("%s: channel %d: no remote_id",
__func__, c->self);
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_CLOSE)) != 0 ||
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
fatal("%s: send CHANNEL_EOF: %s", __func__, ssh_err(r));
c->flags |= CHAN_CLOSE_SENT;
}
}
static void
chan_send_eof2(struct ssh *ssh, Channel *c)
{
int r;
debug2("channel %d: send eof", c->self);
switch (c->istate) {
case CHAN_INPUT_WAIT_DRAIN:
if (!c->have_remote_id)
fatal("%s: channel %d: no remote_id",
__func__, c->self);
if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_EOF)) != 0 ||
(r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
fatal("%s: send CHANNEL_EOF: %s", __func__, ssh_err(r));
c->flags |= CHAN_EOF_SENT;
break;
default:
error("channel %d: cannot send eof for istate %d",
c->self, c->istate);
break;
}
}
/*
* Performs the interactive session. This handles data transmission between
* the client and the program. Note that the notion of stdin, stdout, and
* stderr in this function is sort of reversed: this function writes to
* stdin (of the child program), and reads from stdout and stderr (of the
* child program).
*/
void
server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
struct ssh *ssh = active_state; /* XXX */
fd_set *readset = NULL, *writeset = NULL;
int max_fd = 0;
u_int nalloc = 0;
int wait_status; /* Status returned by wait(). */
pid_t wait_pid; /* pid returned by wait(). */
int waiting_termination = 0; /* Have displayed waiting close message. */
u_int64_t max_time_milliseconds;
u_int previous_stdout_buffer_bytes;
u_int stdout_buffer_bytes;
int r, type;
debug("Entering interactive session.");
/* Initialize the SIGCHLD kludge. */
child_terminated = 0;
signal(SIGCHLD, sigchld_handler);
if (!use_privsep) {
signal(SIGTERM, sigterm_handler);
signal(SIGINT, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
}
/* Initialize our global variables. */
fdin = fdin_arg;
fdout = fdout_arg;
fderr = fderr_arg;
/* nonblocking IO */
set_nonblock(fdin);
set_nonblock(fdout);
/* we don't have stderr for interactive terminal sessions, see below */
if (fderr != -1)
set_nonblock(fderr);
if (!(ssh->compat & SSH_BUG_IGNOREMSG) && isatty(fdin))
fdin_is_tty = 1;
connection_in = ssh_packet_get_connection_in(ssh);
connection_out = ssh_packet_get_connection_out(ssh);
notify_setup();
previous_stdout_buffer_bytes = 0;
/* Set approximate I/O buffer size. */
if (ssh_packet_is_interactive(ssh))
buffer_high = 4096;
else
buffer_high = 64 * 1024;
#if 0
/* Initialize max_fd to the maximum of the known file descriptors. */
max_fd = MAX(connection_in, connection_out);
max_fd = MAX(max_fd, fdin);
max_fd = MAX(max_fd, fdout);
if (fderr != -1)
max_fd = MAX(max_fd, fderr);
#endif
/* Initialize Initialize buffers. */
if ((stdin_buffer = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((stdout_buffer = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((stderr_buffer = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
/*
* If we have no separate fderr (which is the case when we have a pty
* - there we cannot make difference between data sent to stdout and
* stderr), indicate that we have seen an EOF from stderr. This way
* we don't need to check the descriptor everywhere.
*/
if (fderr == -1)
fderr_eof = 1;
server_init_dispatch(ssh);
/* Main loop of the server for the interactive session mode. */
for (;;) {
/* Process buffered packets from the client. */
process_buffered_input_packets(ssh);
/*
* If we have received eof, and there is no more pending
* input data, cause a real eof by closing fdin.
*/
if (stdin_eof && fdin != -1 && sshbuf_len(stdin_buffer) == 0) {
if (fdin != fdout)
close(fdin);
else
shutdown(fdin, SHUT_WR); /* We will no longer send. */
fdin = -1;
}
/* Make packets from buffered stderr data to send to the client. */
make_packets_from_stderr_data(ssh);
/*
* Make packets from buffered stdout data to send to the
* client. If there is very little to send, this arranges to
* not send them now, but to wait a short while to see if we
* are getting more data. This is necessary, as some systems
* wake up readers from a pty after each separate character.
*/
max_time_milliseconds = 0;
stdout_buffer_bytes = sshbuf_len(stdout_buffer);
if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
stdout_buffer_bytes != previous_stdout_buffer_bytes) {
/* try again after a while */
max_time_milliseconds = 10;
} else {
/* Send it now. */
make_packets_from_stdout_data(ssh);
}
previous_stdout_buffer_bytes = sshbuf_len(stdout_buffer);
/* Send channel data to the client. */
if (ssh_packet_not_very_much_data_to_write(ssh))
channel_output_poll();
/*
* Bail out of the loop if the program has closed its output
* descriptors, and we have no more data to send to the
* client, and there is no pending buffered data.
*/
if (fdout_eof && fderr_eof && !ssh_packet_have_data_to_write(ssh) &&
sshbuf_len(stdout_buffer) == 0 && sshbuf_len(stderr_buffer) == 0) {
if (!channel_still_open())
break;
if (!waiting_termination) {
const char *s = "Waiting for forwarded connections to terminate...\r\n";
char *cp = channel_open_message();
waiting_termination = 1;
/* Display list of open channels. */
if ((r = sshbuf_put(stderr_buffer,
s, strlen(s))) != 0 ||
(r = sshbuf_put(stderr_buffer,
s, strlen(s))) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
free(cp);
}
}
max_fd = MAX(connection_in, connection_out);
max_fd = MAX(max_fd, fdin);
max_fd = MAX(max_fd, fdout);
max_fd = MAX(max_fd, fderr);
max_fd = MAX(max_fd, notify_pipe[0]);
/* Sleep in select() until we can do something. */
wait_until_can_do_something(ssh, &readset, &writeset, &max_fd,
&nalloc, max_time_milliseconds);
if (received_sigterm) {
logit("Exiting on signal %d", (int)received_sigterm);
/* Clean up sessions, utmp, etc. */
cleanup_exit(255);
}
/* Process any channel events. */
channel_after_select(readset, writeset);
/* Process input from the client and from program stdout/stderr. */
process_input(ssh, readset);
/* Process output to the client and to program stdin. */
process_output(ssh, writeset);
}
free(readset);
free(writeset);
/* Cleanup and termination code. */
/* Wait until all output has been sent to the client. */
drain_output(ssh);
debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
/* Free and clear the buffers. */
sshbuf_free(stdin_buffer);
sshbuf_free(stdout_buffer);
sshbuf_free(stderr_buffer);
/* Close the file descriptors. */
if (fdout != -1)
close(fdout);
fdout = -1;
fdout_eof = 1;
if (fderr != -1)
close(fderr);
fderr = -1;
fderr_eof = 1;
if (fdin != -1)
close(fdin);
fdin = -1;
channel_free_all();
/* We no longer want our SIGCHLD handler to be called. */
signal(SIGCHLD, SIG_DFL);
while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
if (errno != EINTR)
ssh_packet_disconnect(ssh, "wait: %.100s", strerror(errno));
if (wait_pid != pid)
error("Strange, wait returned pid %ld, expected %ld",
(long)wait_pid, (long)pid);
/* Check if it exited normally. */
if (WIFEXITED(wait_status)) {
/* Yes, normal exit. Get exit status and send it to the client. */
debug("Command exited with status %d.", WEXITSTATUS(wait_status));
if ((r = sshpkt_start(ssh, SSH_SMSG_EXITSTATUS)) != 0 ||
(r = sshpkt_put_u32(ssh, WEXITSTATUS(wait_status))) != 0 ||
(r = sshpkt_send(ssh)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
ssh_packet_write_wait(ssh);
/*
* Wait for exit confirmation. Note that there might be
* other packets coming before it; however, the program has
* already died so we just ignore them. The client is
* supposed to respond with the confirmation when it receives
* the exit status.
*/
do {
type = ssh_packet_read(ssh);
}
while (type != SSH_CMSG_EXIT_CONFIRMATION);
debug("Received exit confirmation.");
return;
}
/* Check if the program terminated due to a signal. */
if (WIFSIGNALED(wait_status))
ssh_packet_disconnect(ssh, "Command terminated on signal %d.",
WTERMSIG(wait_status));
/* Some weird exit cause. Just exit. */
ssh_packet_disconnect(ssh, "wait returned status %04x.", wait_status);
/* NOTREACHED */
}
