/* process a packet, and also check that auth has been done */
static void process_postauth_packet(unsigned int type) {
/* messages following here require userauth before use */
if (!ses.authstate.authdone) {
dropbear_exit("received message %d before userauth", type);
}
switch (type) {
case SSH_MSG_CHANNEL_DATA:
recv_msg_channel_data();
break;
case SSH_MSG_CHANNEL_WINDOW_ADJUST:
recv_msg_channel_window_adjust();
break;
case SSH_MSG_CHANNEL_REQUEST:
recv_msg_channel_request();
break;
case SSH_MSG_CHANNEL_OPEN:
recv_msg_channel_open();
break;
case SSH_MSG_CHANNEL_EOF:
recv_msg_channel_eof();
break;
case SSH_MSG_CHANNEL_CLOSE:
recv_msg_channel_close();
break;
#ifdef USE_LISTENERS /* for x11, tcp fwd etc */
case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
recv_msg_channel_open_confirmation();
break;
case SSH_MSG_CHANNEL_OPEN_FAILURE:
recv_msg_channel_open_failure();
break;
#endif
default:
TRACE(("unknown packet()"));
recv_unimplemented();
break;
}
}
/* process a decrypted packet, call the appropriate handler */
void process_packet() {
unsigned char type;
unsigned int i;
TRACE2(("enter process_packet"))
type = buf_getbyte(ses.payload);
TRACE(("process_packet: packet type = %d, len %d", type, ses.payload->len))
ses.lastpacket = type;
ses.last_packet_time = time(NULL);
/* These packets we can receive at any time */
switch(type) {
case SSH_MSG_IGNORE:
goto out;
case SSH_MSG_DEBUG:
goto out;
case SSH_MSG_UNIMPLEMENTED:
/* debugging XXX */
TRACE(("SSH_MSG_UNIMPLEMENTED"))
dropbear_exit("Received SSH_MSG_UNIMPLEMENTED");
case SSH_MSG_DISCONNECT:
/* TODO cleanup? */
dropbear_close("Disconnect received");
}
/* This applies for KEX, where the spec says the next packet MUST be
* NEWKEYS */
if (ses.requirenext != 0) {
if (ses.requirenext == type)
{
/* Got what we expected */
TRACE(("got expected packet %d during kexinit", type))
}
else
{
/* RFC4253 7.1 - various messages are allowed at this point.
The only ones we know about have already been handled though,
so just return "unimplemented" */
if (type >= 1 && type <= 49
&& type != SSH_MSG_SERVICE_REQUEST
&& type != SSH_MSG_SERVICE_ACCEPT
&& type != SSH_MSG_KEXINIT)
{
TRACE(("unknown allowed packet during kexinit"))
recv_unimplemented();
goto out;
}
else
{
TRACE(("disallowed packet during kexinit"))
dropbear_exit("Unexpected packet type %d, expected %d", type,
ses.requirenext);
}
}
}
/* Check if we should ignore this packet. Used currently only for
* KEX code, with first_kex_packet_follows */
if (ses.ignorenext) {
TRACE(("Ignoring packet, type = %d", type))
ses.ignorenext = 0;
goto out;
}
/* Only clear the flag after we have checked ignorenext */
if (ses.requirenext != 0 && ses.requirenext == type)
{
ses.requirenext = 0;
}
/* Kindly the protocol authors gave all the preauth packets type values
* less-than-or-equal-to 60 ( == MAX_UNAUTH_PACKET_TYPE ).
* NOTE: if the protocol changes and new types are added, revisit this
* assumption */
if ( !ses.authstate.authdone && type > MAX_UNAUTH_PACKET_TYPE ) {
dropbear_exit("Received message %d before userauth", type);
}
for (i = 0; ; i++) {
if (ses.packettypes[i].type == 0) {
/* end of list */
break;
}
if (ses.packettypes[i].type == type) {
ses.packettypes[i].handler();
goto out;
}
}
/* TODO do something more here? */
TRACE(("preauth unknown packet"))
recv_unimplemented();
out:
buf_free(ses.payload);
ses.payload = NULL;
TRACE2(("leave process_packet"))
}
/* process a decrypted packet, call the appropriate handler */
void process_packet() {
unsigned char type;
TRACE(("enter process_packet"));
type = buf_getbyte(ses.payload);
TRACE(("process_packet: packet type = %d", type));
/* these packets we can receive at any time, regardless of expecting
* other packets: */
switch(type) {
case SSH_MSG_IGNORE:
case SSH_MSG_DEBUG:
TRACE(("received SSH_MSG_IGNORE or SSH_MSG_DEBUG"));
goto out;
case SSH_MSG_UNIMPLEMENTED:
/* debugging XXX */
TRACE(("SSH_MSG_UNIMPLEMENTED"));
dropbear_exit("received SSH_MSG_UNIMPLEMENTED");
case SSH_MSG_DISCONNECT:
/* TODO cleanup? */
dropbear_close("Disconnect received");
}
/* check that we aren't expecting a particular packet */
if (ses.expecting && ses.expecting != type) {
/* TODO send disconnect? */
dropbear_exit("unexpected packet type %d, expected %d", type,
ses.expecting);
}
/* handle the packet depending on type */
ses.expecting = 0;
switch (type) {
case SSH_MSG_SERVICE_REQUEST:
recv_msg_service_request();
break;
case SSH_MSG_USERAUTH_REQUEST:
recv_msg_userauth_request();
break;
case SSH_MSG_KEXINIT:
recv_msg_kexinit();
break;
case SSH_MSG_KEXDH_INIT:
recv_msg_kexdh_init();
break;
case SSH_MSG_NEWKEYS:
recv_msg_newkeys();
break;
/* this is ugly, need to make a cleaner way to do it */
case SSH_MSG_CHANNEL_DATA:
case SSH_MSG_CHANNEL_WINDOW_ADJUST:
case SSH_MSG_CHANNEL_REQUEST:
case SSH_MSG_CHANNEL_OPEN:
case SSH_MSG_CHANNEL_EOF:
case SSH_MSG_CHANNEL_CLOSE:
case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
case SSH_MSG_CHANNEL_OPEN_FAILURE:
/* these should be checked for authdone below */
process_postauth_packet(type);
break;
default:
/* TODO this possibly should be handled */
TRACE(("unknown packet"));
recv_unimplemented();
break;
}
out:
buf_free(ses.payload);
ses.payload = NULL;
TRACE(("leave process_packet"));
}
/* process a decrypted packet, call the appropriate handler */
void process_packet() {
unsigned char type;
unsigned int i;
TRACE(("enter process_packet"))
type = buf_getbyte(ses.payload);
TRACE(("process_packet: packet type = %d", type))
ses.lastpacket = type;
/* These packets we can receive at any time */
switch(type) {
case SSH_MSG_IGNORE:
case SSH_MSG_DEBUG:
TRACE(("received SSH_MSG_IGNORE or SSH_MSG_DEBUG"))
goto out;
case SSH_MSG_UNIMPLEMENTED:
/* debugging XXX */
TRACE(("SSH_MSG_UNIMPLEMENTED"))
dropbear_exit("received SSH_MSG_UNIMPLEMENTED");
case SSH_MSG_DISCONNECT:
/* TODO cleanup? */
dropbear_close("Disconnect received");
}
/* This applies for KEX, where the spec says the next packet MUST be
* NEWKEYS */
if (ses.requirenext != 0) {
if (ses.requirenext != type) {
/* TODO send disconnect? */
dropbear_exit("unexpected packet type %d, expected %d", type,
ses.requirenext);
} else {
/* Got what we expected */
ses.requirenext = 0;
}
}
/* Check if we should ignore this packet. Used currently only for
* KEX code, with first_kex_packet_follows */
if (ses.ignorenext) {
TRACE(("Ignoring packet, type = %d", type))
ses.ignorenext = 0;
goto out;
}
/* Kindly the protocol authors gave all the preauth packets type values
* less-than-or-equal-to 60 ( == MAX_UNAUTH_PACKET_TYPE ).
* NOTE: if the protocol changes and new types are added, revisit this
* assumption */
if ( !ses.authstate.authdone && type > MAX_UNAUTH_PACKET_TYPE ) {
dropbear_exit("received message %d before userauth", type);
}
for (i = 0; ; i++) {
if (ses.packettypes[i].type == 0) {
/* end of list */
break;
}
if (ses.packettypes[i].type == type) {
ses.packettypes[i].handler();
goto out;
}
}
/* TODO do something more here? */
TRACE(("preauth unknown packet"))
recv_unimplemented();
out:
buf_free(ses.payload);
ses.payload = NULL;
TRACE(("leave process_packet"))
}
