search for: ssh_msg_channel_data

The full SSH_MSG_CHANNEL_DATA packet looks like this: uint32 packet length byte SSH_MSG_CHANNEL_DATA uint32 recipient channel uint32 nr data bytes byte[] data OpenSSH_6.1p1 considers that the 'maximum packet size' from SSH_MSG_CHANNEL_OPEN or SSH_MSG_CHANNEL_OPEN_CONFIRMATION impacts only the 'byt...

In SSHv2, the data that consumes window space is that sent in the channel data and channel data extended messages. My question is, how is the data that consumes window space reckoned? One would have thought that it is the total length of the message itself, but the standard seems to imply that only the data contained in the data string field in the messages above is to be taken into account. That

...ze, so far without much success :-( My understanding is that when a client specifies a window size N at the beginning of a session, it is letting the server know that it (the server) can send, on a given channel, up to N bytes worth of data that consumes window space (essentially the payload of SSH_MSG_CHANNEL_DATA and one or two more packets.) If the server sends more data of that type than allowed by the window size in the channel, the client is free to ignore such data silently. Therefore, the server has to wait for the client to send a window size adjust packet before sending more data. Again, if I und...

...pens(char *); void channel_clear_permitted_opens(void); void channel_input_port_forward_request(int, int); int channel_connect_to(const char *, u_short); --- clientloop.c 28 Jan 2003 18:06:51 -0000 1.1.1.2 +++ clientloop.c 28 Jan 2003 19:06:35 -0000 1.3 @@ -1342,7 +1344,7 @@ dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); - dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); + dispatch_set(SSH_MSG_PORT_OPEN, &...

...packet_get_maxsize()/ 2) len = packet_get_maxsize()/2; } } if (len > 0) { packet_start(compat20 ? SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); packet_put_int(c->remote_id); packet_put_string(buffer_ptr(&c- >input), len); packet_send(); buffer_consume(&c->input, len);...

When I encounter the problem with TCP port forwarding locking up, I'll see this on the client window (if I haven't invoked ssh with -q): chan_shutdown_read failed for #1/fd6: Transport endpoint is not connected chan_shutdown_read failed for #1/fd6: Transport endpoint is not connected This is with Blowfish encryption. I have to kill and restart the client when this happens. Phil

...letimeout_check(int type) +{ + /* No-op, if idletimeouts are not configured */ + if (idletimeout==0) return; + + /* The following packets reset idletimeout on input or output. + * Note that only actual data resets idletimeout, control packets + * do not. */ + switch(type) { + case SSH_MSG_CHANNEL_DATA: + case SSH_CMSG_STDIN_DATA: + case SSH_SMSG_STDOUT_DATA: + case SSH_SMSG_STDERR_DATA: + case SSH2_MSG_CHANNEL_DATA: + case SSH2_MSG_CHANNEL_EXTENDED_DATA: + time(&idletime_last); + } +} + +int +packet_select(int maxfds, + fd_set *readset, fd_set *writeset, fd_set *exceptset, +...

...if (c != NULL) { @@ -1256,20 +1268,28 @@ client_init_dispatch_13(void) { dispatch_init(NULL); +#ifdef WITH_PROTO13 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); +#endif dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); +#ifdef WITH_TCPFWD dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); +#endif dispatch_...

Hi, sorry if it is the wrong approuch to suggest improvments to OpenSSH, but here comes my suggestion: I recently stumbled upon the scponly shell which in it's chroot:ed form is an ideal solution when you want to share some files with people you trust more or less. The problem is, if you use the scponlyc as shell, port forwarding is still allowed. This can of course be dissallowed in

...ut_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); - packet_put_cstring("bla bla"); + packet_put_cstring("bla bla"); /* TODO: Perhaps a little better + explanation */ packet_put_cstring(""); packet_send(); } @@ -1045,7 +1052,7 @@ dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); - dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); + dispatch_set(SSH_MSG_PORT_OPEN, &...

I'm reading this fine article on O'Reilly: http://linux.oreillynet.com/lpt/a//linux/2001/11/08/ssh_keystroke.html <quote> The paper concludes that the keystroke timing data observable from today's SSH implementations reveals a dangerously significant amount of information about user terminal sessions--enough to locate typed passwords in the session data stream and reduce the

...d use_steno_timing_manipulation + * to channel_output_poll. +*/ void -channel_output_poll() +channel_output_poll(int *bogus_send_count, int use_steno_timing_manipulation) { int len, i; Channel *c; @@ -1649,11 +1678,49 @@ SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); packet_put_int(c->remote_id); packet_put_string(buffer_ptr(&c->input), len); + /* + * Begin SD Mod: if using SSH2 and it is + *...

I am running OpenSSH 2.9p1 on SunOS 5.7 w/4-24-2001 patch cluster. Like many other users I am seeing the hanging session on logout with background processes. This is a huge problem for me as I centrally manage 50+ machines with rdist across ssh. Instead of just complaining about the problem I thought I would put my CS degree to use and try to track down the problem myself. For starters,

Hello, In response to the timing analysis attacks presented by Dawn Song et. al. in her paper http://paris.cs.berkeley.edu/~dawnsong/ssh-timing.html we at Silicon Defense developed a patch for openssh to avoid such measures. Timing Analysis Evasion changes were developed by C. Jason Coit and Roel Jonkman of Silicon Defense. These changes cause SSH to send packets unless request not to,

...xfree(ucp); +#endif } diff -bur openssh-3.7.1p2.orig/channels.c openssh-3.7.1p2/channels.c --- openssh-3.7.1p2.orig/channels.c Tue Sep 16 23:34:12 2003 +++ openssh-3.7.1p2/channels.c Tue Oct 7 08:22:00 2003 @@ -1752,7 +1752,11 @@ packet_start(compat20 ? SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); packet_put_int(c->remote_id); + /*if (strcmp(c->ctype, "session") == 0)*/ + if (c->ctype[0] == 's') packet_put_string(buffer_ptr(&c->input), len); + else + packet_put_binary(buffer_ptr(&c->input), len); packet_send(); bu...