I have a problem using stunnel v 4.05 under Linux with kernel 2.4.27. My target is using two PC connected via serial port with trafic crypted. I have achieved this schema:

+-------+ +-------+ | | | | | PC1 |------------rs232---------| PC2 | | |10.0.0.1 10.0.0.2| | | | | | +-------+ +-------+

I have started pppd in raw mode in PC1 and PC2 and i have verified (with ping)that the link is OK for trafic without criptyng.

Below i have tried to "mount" a tunnel cripted between PC1 and PC2 but stunnel server side return an error in openpty function.

The stunnel.conf server side (PC1) is: --------------------------------------

cert = /usr/local/etc/stunnel/stunnel.pem chroot = /var/run/stunnel/ pid = setuid = nobody setgid = nobody

# Some debugging stuff debug = 7 output = /var/log/stunnel.log

foreground=no

# Service-level configuration [ppp] accept = 2020 exec = /usr/sbin/pppd execargs = pppd local pty = yes

The stunnel.conf client side (PC2) is: --------------------------------------

cert = /usr/local/etc/stunnel/stunnel.pem chroot = /var/run/stunnel/ pid = setuid = nobody setgid = nobody

# Some debugging stuff debug = 7 output = /var/log/stunnel.log

# Use it for client mode client = yes

connect = 10.0.0.1:2020 exec = /usr/sbin/pppd execargs = pppd local

The log file server side (PC1) is: ---------------------------------- 2004.10.27 07:25:19 LOG5[5246:16384]: stunnel 4.05 on i686-pc-linux-gnu PTHREAD+LIBWRAP with OpenSSL 0.9.7a Feb 19 2003 2004.10.27 07:25:19 LOG7[5246:16384]: RAND_status claims sufficient entropy for the PRNG 2004.10.27 07:25:19 LOG6[5246:16384]: PRNG seeded successfully 2004.10.27 07:25:19 LOG7[5246:16384]: Certificate: /usr/local/etc/stunnel/stunnel.pem 2004.10.27 07:25:19 LOG7[5246:16384]: Key file: /usr/local/etc/stunnel/stunnel.pem 2004.10.27 07:25:19 LOG5[5246:16384]: FD_SETSIZE=1024, file ulimit=1024 -> 500 clients allowed 2004.10.27 07:25:19 LOG7[5246:16384]: FD 4 in non-blocking mode 2004.10.27 07:25:19 LOG7[5246:16384]: SO_REUSEADDR option set on accept socket 2004.10.27 07:25:19 LOG7[5246:16384]: ppp bound to 0.0.0.0:2020 2004.10.27 07:25:19 LOG7[5246:16384]: FD 5 in non-blocking mode 2004.10.27 07:25:19 LOG7[5246:16384]: FD 6 in non-blocking mode 2004.10.27 07:25:19 LOG7[5247:16384]: No pid file being created 2004.10.27 07:25:59 LOG7[5247:16384]: ppp accepted FD=7 from 10.0.0.2:39791 2004.10.27 07:25:59 LOG7[5247:16384]: FD 7 in non-blocking mode 2004.10.27 07:25:59 LOG7[5251:16386]: ppp started 2004.10.27 07:25:59 LOG5[5251:16386]: ppp connected from 10.0.0.2:39791 2004.10.27 07:25:59 LOG7[5251:16386]: SSL state (accept): before/accept initialization 2004.10.27 07:25:59 LOG7[5251:16386]: waitforsocket: FD=7, DIR=read 2004.10.27 07:25:59 LOG7[5251:16386]: waitforsocket: ok 2004.10.27 07:25:59 LOG7[5251:16386]: SSL state (accept): SSLv3 read client hello A 2004.10.27 07:25:59 LOG7[5251:16386]: SSL state (accept): SSLv3 write server hello A 2004.10.27 07:25:59 LOG7[5251:16386]: SSL state (accept): SSLv3 write certificate A 2004.10.27 07:25:59 LOG7[5251:16386]: SSL state (accept): SSLv3 write server done A 2004.10.27 07:25:59 LOG7[5251:16386]: SSL state (accept): SSLv3 flush data 2004.10.27 07:25:59 LOG7[5251:16386]: waitforsocket: FD=7, DIR=read 2004.10.27 07:26:00 LOG7[5251:16386]: waitforsocket: ok 2004.10.27 07:26:00 LOG7[5251:16386]: SSL state (accept): SSLv3 read client key exchange A 2004.10.27 07:26:00 LOG7[5251:16386]: SSL state (accept): SSLv3 read finished A 2004.10.27 07:26:00 LOG7[5251:16386]: SSL state (accept): SSLv3 write change cipher spec A 2004.10.27 07:26:00 LOG7[5251:16386]: SSL state (accept): SSLv3 write finished A 2004.10.27 07:26:00 LOG7[5251:16386]: SSL state (accept): SSLv3 flush data 2004.10.27 07:26:00 LOG7[5251:16386]: 1 items in the session cache 2004.10.27 07:26:00 LOG7[5251:16386]: 0 client connects (SSL_connect()) 2004.10.27 07:26:00 LOG7[5251:16386]: 0 client connects that finished 2004.10.27 07:26:00 LOG7[5251:16386]: 0 client renegotiatations requested 2004.10.27 07:26:00 LOG7[5251:16386]: 1 server connects (SSL_accept()) 2004.10.27 07:26:00 LOG7[5251:16386]: 1 server connects that finished 2004.10.27 07:26:00 LOG7[5251:16386]: 0 server renegotiatiations requested 2004.10.27 07:26:00 LOG7[5251:16386]: 0 session cache hits 2004.10.27 07:26:00 LOG7[5251:16386]: 0 session cache misses 2004.10.27 07:26:00 LOG7[5251:16386]: 0 session cache timeouts 2004.10.27 07:26:00 LOG6[5251:16386]: Negotiated ciphers: AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 2004.10.27 07:26:00 LOG7[5251:16386]: pty_allocate:namebuf=, namebuflen=1024 : Success (0) 2004.10.27 07:26:00 LOG3[5251:16386]: openpty: No such file or directory (2) 2004.10.27 07:26:00 LOG3[5251:16386]: Failed to initialize remote connection 2004.10.27 07:26:00 LOG7[5251:16386]: ppp finished (0 left)

The log file client side (PC2) is: ---------------------------------- 2004.10.27 07:20:16 LOG5[4460:16384]: stunnel 4.05 on i686-pc-linux-gnu PTHREAD+LIBWRAP with OpenSSL 0.9.7a Feb 19 2003 2004.10.27 07:20:16 LOG7[4460:16384]: RAND_status claims sufficient entropy for the PRNG 2004.10.27 07:20:16 LOG6[4460:16384]: PRNG seeded successfully 2004.10.27 07:20:16 LOG7[4460:16384]: Certificate: /usr/local/etc/stunnel/stunnel.pem 2004.10.27 07:20:16 LOG7[4460:16384]: Key file: /usr/local/etc/stunnel/stunnel.pem 2004.10.27 07:20:16 LOG7[4460:16384]: stunnel started 2004.10.27 07:20:16 LOG6[4460:16384]: Local mode child started (PID=4461) 2004.10.27 07:20:16 LOG5[4460:16384]: stunnel connected from 127.0.0.1:39790 2004.10.27 07:20:16 LOG7[4460:16384]: FD 4 in non-blocking mode 2004.10.27 07:20:16 LOG7[4460:16384]: stunnel connecting 10.0.0.1:2020 2004.10.27 07:20:16 LOG7[4460:16384]: remote connect #1: EINPROGRESS: retrying 2004.10.27 07:20:16 LOG7[4460:16384]: waitforsocket: FD=4, DIR=write 2004.10.27 07:20:16 LOG3[4461:16384]: /usr/sbin/pppd: No such file or directory (2) 2004.10.27 07:20:16 LOG7[4460:16384]: waitforsocket: ok 2004.10.27 07:20:16 LOG7[4460:16384]: Remote FD=4 initialized 2004.10.27 07:20:16 LOG7[4460:16384]: SSL state (connect): before/connect initialization 2004.10.27 07:20:16 LOG7[4460:16384]: SSL state (connect): SSLv3 write client hello A 2004.10.27 07:20:16 LOG7[4460:16384]: waitforsocket: FD=4, DIR=read 2004.10.27 07:20:17 LOG7[4460:16384]: waitforsocket: ok 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 read server hello A 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 read server certificate A 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 read server done A 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 write client key exchange A 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 write change cipher spec A 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 write finished A 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 flush data 2004.10.27 07:20:17 LOG7[4460:16384]: waitforsocket: FD=4, DIR=read 2004.10.27 07:20:17 LOG7[4460:16384]: waitforsocket: ok 2004.10.27 07:20:17 LOG7[4460:16384]: SSL state (connect): SSLv3 read finished A 2004.10.27 07:20:17 LOG7[4460:16384]: 1 items in the session cache 2004.10.27 07:20:17 LOG7[4460:16384]: 1 client connects (SSL_connect()) 2004.10.27 07:20:17 LOG7[4460:16384]: 1 client connects that finished 2004.10.27 07:20:17 LOG7[4460:16384]: 0 client renegotiatations requested 2004.10.27 07:20:17 LOG7[4460:16384]: 0 server connects (SSL_accept()) 2004.10.27 07:20:17 LOG7[4460:16384]: 0 server connects that finished 2004.10.27 07:20:17 LOG7[4460:16384]: 0 server renegotiatiations requested 2004.10.27 07:20:17 LOG7[4460:16384]: 0 session cache hits 2004.10.27 07:20:17 LOG7[4460:16384]: 0 session cache misses 2004.10.27 07:20:17 LOG7[4460:16384]: 0 session cache timeouts 2004.10.27 07:20:17 LOG6[4460:16384]: Negotiated ciphers: AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 2004.10.27 07:20:17 LOG7[4460:16384]: Socket closed on read 2004.10.27 07:20:17 LOG7[4460:16384]: SSL write shutdown (output buffer empty) 2004.10.27 07:20:17 LOG7[4460:16384]: SSL alert (write): warning: close notify 2004.10.27 07:20:17 LOG7[4460:16384]: SSL_shutdown retrying 2004.10.27 07:20:17 LOG3[4460:16384]: SSL_read (ERROR_SYSCALL): Connection reset by peer (104) 2004.10.27 07:20:17 LOG5[4460:16384]: Connection reset: 0 bytes sent to SSL, 0 bytes sent to socket 2004.10.27 07:20:17 LOG7[4460:16384]: stunnel finished (0 left)

Any suggestion ?

Thanks in advance..

Angelo Raspanti