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#include "includes.h"
#include "session.h"
#include "dbutil.h"
#include "kex.h"
#include "ssh.h"
#include "packet.h"
#include "tcpfwd.h"
#include "channel.h"
#include "random.h"
#include "service.h"
#include "runopts.h"
#include "chansession.h"
static void cli_remoteclosed();
static void cli_sessionloop();
static void cli_session_init();
static void cli_finished();
struct clientsession cli_ses; /* GLOBAL */
/* Sorted in decreasing frequency will be more efficient - data and window
* should be first */
static const packettype cli_packettypes[] = {
/* TYPE, AUTHREQUIRED, FUNCTION */
{SSH_MSG_CHANNEL_DATA, recv_msg_channel_data},
{SSH_MSG_CHANNEL_WINDOW_ADJUST, recv_msg_channel_window_adjust},
{SSH_MSG_USERAUTH_FAILURE, recv_msg_userauth_failure}, /* client */
{SSH_MSG_USERAUTH_SUCCESS, recv_msg_userauth_success}, /* client */
{SSH_MSG_KEXINIT, recv_msg_kexinit},
{SSH_MSG_KEXDH_REPLY, recv_msg_kexdh_reply}, /* client */
{SSH_MSG_NEWKEYS, recv_msg_newkeys},
{SSH_MSG_SERVICE_ACCEPT, recv_msg_service_accept}, /* client */
{SSH_MSG_CHANNEL_REQUEST, recv_msg_channel_request},
{SSH_MSG_CHANNEL_OPEN, recv_msg_channel_open},
{SSH_MSG_CHANNEL_EOF, recv_msg_channel_eof},
{SSH_MSG_CHANNEL_CLOSE, recv_msg_channel_close},
{SSH_MSG_CHANNEL_OPEN_CONFIRMATION, recv_msg_channel_open_confirmation},
{SSH_MSG_CHANNEL_OPEN_FAILURE, recv_msg_channel_open_failure},
{SSH_MSG_USERAUTH_BANNER, recv_msg_userauth_banner}, /* client */
#ifdef DROPBEAR_PUBKEY_AUTH
{SSH_MSG_USERAUTH_PK_OK, recv_msg_userauth_pk_ok}, /* client */
#endif
{0, 0} /* End */
};
static const struct ChanType *cli_chantypes[] = {
#ifdef ENABLE_CLI_REMOTETCPFWD
&cli_chan_tcpremote,
#endif
NULL /* Null termination */
};
void cli_session(int sock, char* remotehost) {
crypto_init();
common_session_init(sock, remotehost);
chaninitialise(cli_chantypes);
/* Set up cli_ses vars */
cli_session_init();
/* Ready to go */
sessinitdone = 1;
/* Exchange identification */
session_identification();
seedrandom();
send_msg_kexinit();
/* XXX here we do stuff differently */
session_loop(cli_sessionloop);
/* Not reached */
}
static void cli_session_init() {
cli_ses.state = STATE_NOTHING;
cli_ses.kex_state = KEX_NOTHING;
cli_ses.tty_raw_mode = 0;
cli_ses.winchange = 0;
/* Auth */
cli_ses.lastpubkey = NULL;
cli_ses.lastauthtype = NULL;
/* For printing "remote host closed" for the user */
ses.remoteclosed = cli_remoteclosed;
ses.buf_match_algo = cli_buf_match_algo;
/* packet handlers */
ses.packettypes = cli_packettypes;
ses.isserver = 0;
}
/* This function drives the progress of the session - it initiates KEX,
* service, userauth and channel requests */
static void cli_sessionloop() {
TRACE(("enter cli_sessionloop"));
if (ses.lastpacket == SSH_MSG_KEXINIT && cli_ses.kex_state == KEX_NOTHING) {
cli_ses.kex_state = KEXINIT_RCVD;
}
if (cli_ses.kex_state == KEXINIT_RCVD) {
/* We initiate the KEXDH. If DH wasn't the correct type, the KEXINIT
* negotiation would have failed. */
send_msg_kexdh_init();
cli_ses.kex_state = KEXDH_INIT_SENT;
TRACE(("leave cli_sessionloop: done with KEXINIT_RCVD"));
return;
}
/* A KEX has finished, so we should go back to our KEX_NOTHING state */
if (cli_ses.kex_state != KEX_NOTHING && ses.kexstate.recvkexinit == 0
&& ses.kexstate.sentkexinit == 0) {
cli_ses.kex_state = KEX_NOTHING;
}
/* We shouldn't do anything else if a KEX is in progress */
if (cli_ses.kex_state != KEX_NOTHING) {
TRACE(("leave cli_sessionloop: kex_state != KEX_NOTHING"));
return;
}
/* We should exit if we haven't donefirstkex: we shouldn't reach here
* in normal operation */
if (ses.kexstate.donefirstkex == 0) {
TRACE(("XXX XXX might be bad! leave cli_sessionloop: haven't donefirstkex"));
return;
}
switch (cli_ses.state) {
case STATE_NOTHING:
/* We've got the transport layer sorted, we now need to request
* userauth */
send_msg_service_request(SSH_SERVICE_USERAUTH);
cli_ses.state = SERVICE_AUTH_REQ_SENT;
TRACE(("leave cli_sessionloop: sent userauth service req"));
return;
/* userauth code */
case SERVICE_AUTH_ACCEPT_RCVD:
cli_auth_getmethods();
cli_ses.state = USERAUTH_REQ_SENT;
TRACE(("leave cli_sessionloop: sent userauth methods req"));
return;
case USERAUTH_FAIL_RCVD:
cli_auth_try();
cli_ses.state = USERAUTH_REQ_SENT;
TRACE(("leave cli_sessionloop: cli_auth_try"));
return;
/*
case USERAUTH_SUCCESS_RCVD:
send_msg_service_request(SSH_SERVICE_CONNECTION);
cli_ses.state = SERVICE_CONN_REQ_SENT;
TRACE(("leave cli_sessionloop: sent ssh-connection service req"));
return;
case SERVICE_CONN_ACCEPT_RCVD:
cli_send_chansess_request();
TRACE(("leave cli_sessionloop: cli_send_chansess_request"));
cli_ses.state = SESSION_RUNNING;
return;
*/
case USERAUTH_SUCCESS_RCVD:
#ifdef ENABLE_CLI_LOCALTCPFWD
TRACE(("recvd USERAUTH_SUCCESS_RCVD"));
setup_localtcp();
#endif
cli_send_chansess_request();
TRACE(("leave cli_sessionloop: cli_send_chansess_request"));
cli_ses.state = SESSION_RUNNING;
return;
case SESSION_RUNNING:
if (ses.chancount < 1) {
cli_finished();
}
if (cli_ses.winchange) {
cli_chansess_winchange();
}
return;
/* XXX more here needed */
default:
break;
}
TRACE(("leave cli_sessionloop: fell out"));
}
void cli_session_cleanup() {
if (!sessinitdone) {
return;
}
cli_tty_cleanup();
}
static void cli_finished() {
cli_session_cleanup();
common_session_cleanup();
fprintf(stderr, "Connection to %s@%s:%s closed.\n", cli_opts.username,
cli_opts.remotehost, cli_opts.remoteport);
exit(EXIT_SUCCESS);
}
/* called when the remote side closes the connection */
static void cli_remoteclosed() {
/* XXX TODO perhaps print a friendlier message if we get this but have
* already sent/received disconnect message(s) ??? */
close(ses.sock);
ses.sock = -1;
dropbear_exit("remote closed the connection");
}
/* Operates in-place turning dirty (untrusted potentially containing control
* characters) text into clean text. */
void cleantext(unsigned char* dirtytext) {
unsigned int i, j;
unsigned char c;
j = 0;
for (i = 0; dirtytext[i] != '\0'; i++) {
c = dirtytext[i];
/* We can ignore '\r's */
if ( (c >= ' ' && c <= '~') || c == '\n' || c == '\t') {
dirtytext[j] = c;
j++;
}
}
/* Null terminate */
dirtytext[j] = '\0';
}
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