Here is some more strangeness: 1. (As before) - ssh first time -> succeeds - logout - ssh again -> hangs
2. Another sequence - SESSION 1: ssh first time -> succeeds - SESSION 2: ssh second time -> succeeds (without logging out session 1) - ... - SESSION N: ssh n'th time -> succeeds (without logging out any of the previous ones - logout of any of the first N-sessions - SESSION N+1: ssh -> FAILS - SESSION N+2: ssh -> FAILS - ... So it seems like logging out of an 'ssh over stunnel' session somehow causes 'stunnel' to hang on any succeeding sessions "" wrote at about 14:23:30 -0500 on Thursday, February 15, 2024: > I am using Cygwin stunnel 5.71 on Windows 11 to connect to 'ssh' into my > Ubuntu > server over 'stunnel'. > > - The first time I ssh via stunnel it works fine The second time, I > - try to connect, it hangs with 'ssh -v' showing only the initial > local steps of connection: > > OpenSSH_9.5p1, OpenSSL 3.0.12 24 Oct 2023 > debug1: Reading configuration data /home/myuser/.ssh/config > debug1: Reading configuration data /etc/ssh_config > debug1: Connecting to localhost [::1] port 2222. > debug1: Connection established. > debug1: identity file /home/myuser/.ssh/id_rsa type 0 > debug1: identity file /home/myuser/.ssh/id_rsa-cert type -1 > debug1: identity file /home/myuser/.ssh/id_ecdsa type -1 > debug1: identity file /home/myuser/.ssh/id_ecdsa-cert type -1 > debug1: identity file /home/myuser/.ssh/id_ecdsa_sk type -1 > debug1: identity file /home/myuser/.ssh/id_ecdsa_sk-cert type -1 > debug1: identity file /home/myuser/.ssh/id_ed25519 type -1 > debug1: identity file /home/myuser/.ssh/id_ed25519-cert type -1 > debug1: identity file /home/myuser/.ssh/id_ed25519_sk type -1 > debug1: identity file /home/myuser/.ssh/id_ed25519_sk-cert type -1 > debug1: identity file /home/myuser/.ssh/id_xmss type -1 > debug1: identity file /home/myuser/.ssh/id_xmss-cert type -1 > debug1: identity file /home/myuser/.ssh/id_dsa type -1 > debug1: identity file /home/myuser/.ssh/id_dsa-cert type -1 > debug1: Local version string SSH-2.0-OpenSSH_9.5 > > and '/var/log/stunnel' on the Cygwin client failing early: > > LOG7[main]: Found 1 ready file descriptor(s) > LOG7[main]: FD=4 events=0x1 revents=0x0 > LOG7[main]: FD=8 events=0x1 revents=0x1 > LOG7[main]: FD=10 events=0x1 revents=0x0 > LOG7[main]: Service [ssh] accepted (FD=3) from ::1:52718 > > > - If I connect a *third* (or more times), 'ssh -v' hangs with the same > output as above, but there is *no* additional logging in > '/var/log/stunnel' on the client. > > > It thus is acting as if 'stunnel' on the Cygwin client itself somehow > hangs/becomes unresponsive early in the second 'ssh' connection > attempt. > > Note that the client '/usr/bin/stunnel/ process continues to run so it > doesn't crash. > > Killing and relaunching /usr/bin/stunnel restarts the situation > allowing me to ssh-over-stunel OK on the first attempt but again > hanging on the 2nd and subsequent 'ssh' attempts > > Also, the 'stunnel' server on Ubuntu continues to run throughout since > I can continue to ssh-over-stunnel into it from other machines. > > It doesn't *seem* to be a firewall problem, since it connects fine the > first time. Nor does it seem to be a network or 'stunnel' server > problem. > > Any ideas on why this is happening? > -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
