I get a segmentation fault on first connect. To the default config, i've added the debug = 7 and foreground = yes. I have used for comparison 2 versions 4.09 and 4.10 compiled with default options (./configure, make, make install) It seems like UCONTEXT is not welcome on my machine.
linux:~ # uname -a Linux linux 2.4.20-4GB #1 Mon Mar 17 17:54:44 UTC 2003 i686 unknown unknown GNU/Linux
linux:~ # gcc -v Reading specs from /usr/lib/gcc-lib/i486-suse-linux/3.3/specs Configured with: ../configure --enable-threads=posix --prefix=/usr --with-local-prefix=/usr/local --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib --enable-languages=c,c++,f77,objc,java,ada --disable-checking --enable-libgcj --with-gxx-include-dir=/usr/include/g++ --with-slibdir=/lib --with-system-zlib --enable-shared --enable-__cxa_atexit i486-suse-linux Thread model: posix gcc version 3.3 20030226 (prerelease) (SuSE Linux)
linux:~ # openssl version OpenSSL 0.9.7g 11 Apr 2005
linux:/usr/src/stunnel-4.10 # /usr/local/sbin/stunnel 2005.06.17 11:44:17 LOG5[10371:1]: stunnel 4.10 on i686-pc-linux-gnu UCONTEXT+POLL+IPv4+LIBWRAP with OpenSSL 0.9.7g 11 Apr 2005 2005.06.17 11:44:17 LOG7[10371:1]: RAND_status claims sufficient entropy for the PRNG 2005.06.17 11:44:17 LOG6[10371:1]: PRNG seeded successfully 2005.06.17 11:44:17 LOG7[10371:1]: Certificate: /usr/local/etc/stunnel/server.pem 2005.06.17 11:44:17 LOG7[10371:1]: Key file: /usr/local/etc/stunnel/server.pem 2005.06.17 11:44:17 LOG6[10371:1]: file ulimit = 1024 (can be changed with 'ulimit -n') 2005.06.17 11:44:17 LOG6[10371:1]: poll() used - no FD_SETSIZE limit for file descriptors 2005.06.17 11:44:17 LOG5[10371:1]: 500 clients allowed 2005.06.17 11:44:17 LOG7[10371:1]: FD 3 in non-blocking mode 2005.06.17 11:44:17 LOG7[10371:1]: FD 4 in non-blocking mode 2005.06.17 11:44:17 LOG7[10371:1]: FD 5 in non-blocking mode 2005.06.17 11:44:17 LOG7[10371:1]: SO_REUSEADDR option set on accept socket 2005.06.17 11:44:17 LOG7[10371:1]: pop3s bound to 0.0.0.0:995 2005.06.17 11:44:17 LOG7[10371:1]: FD 6 in non-blocking mode 2005.06.17 11:44:18 LOG7[10371:1]: SO_REUSEADDR option set on accept socket 2005.06.17 11:44:18 LOG7[10371:1]: https bound to 0.0.0.0:443 2005.06.17 11:44:18 LOG7[10371:1]: Created pid file /stunnel.pid 2005.06.17 11:44:18 LOG7[10371:0]: Waiting -1 second(s) for 3 file descriptor(s) 2005.06.17 11:44:20 LOG7[10371:0]: CONTEXT 1, FD=3, (IN)->() 2005.06.17 11:44:20 LOG7[10371:0]: CONTEXT 1, FD=5, (IN)->(IN) 2005.06.17 11:44:20 LOG7[10371:0]: CONTEXT 1, FD=6, (IN)->() 2005.06.17 11:44:20 LOG7[10371:1]: pop3s accepted FD=7 from 172.16.203.52:2148 2005.06.17 11:44:20 LOG7[10371:1]: Creating a new context 2005.06.17 11:44:20 LOG7[10371:1]: Context 2 created Segmentation fault
linux:/usr/src/stunnel-4.09 # /usr/local/sbin/stunnel 2005.06.17 11:45:13 LOG5[10773:16384]: stunnel 4.09 on i686-pc-linux-gnu PTHREAD+POLL+IPv4+LIBWRAP with OpenSSL 0.9.7g 11 Apr 2005 2005.06.17 11:45:13 LOG7[10773:16384]: RAND_status claims sufficient entropy for the PRNG 2005.06.17 11:45:13 LOG6[10773:16384]: PRNG seeded successfully 2005.06.17 11:45:13 LOG7[10773:16384]: Certificate: /usr/local/etc/stunnel/server.pem 2005.06.17 11:45:13 LOG7[10773:16384]: Key file: /usr/local/etc/stunnel/server.pem 2005.06.17 11:45:13 LOG6[10773:16384]: file ulimit = 1024 (can be changed with 'ulimit -n') 2005.06.17 11:45:13 LOG6[10773:16384]: poll() used - no FD_SETSIZE limit for file descriptors 2005.06.17 11:45:13 LOG5[10773:16384]: 500 clients allowed 2005.06.17 11:45:13 LOG7[10773:16384]: FD 3 in non-blocking mode 2005.06.17 11:45:13 LOG7[10773:16384]: FD 4 in non-blocking mode 2005.06.17 11:45:13 LOG7[10773:16384]: FD 5 in non-blocking mode 2005.06.17 11:45:13 LOG7[10773:16384]: SO_REUSEADDR option set on accept socket 2005.06.17 11:45:13 LOG7[10773:16384]: pop3s bound to 0.0.0.0:995 2005.06.17 11:45:13 LOG7[10773:16384]: FD 6 in non-blocking mode 2005.06.17 11:45:13 LOG7[10773:16384]: SO_REUSEADDR option set on accept socket 2005.06.17 11:45:13 LOG7[10773:16384]: https bound to 0.0.0.0:443 2005.06.17 11:45:13 LOG7[10773:16384]: Created pid file /stunnel.pid 2005.06.17 11:45:15 LOG7[10773:16384]: pop3s accepted FD=7 from 172.16.203.52:2150 2005.06.17 11:45:15 LOG7[10773:16384]: FD 7 in non-blocking mode 2005.06.17 11:45:15 LOG7[10779:16386]: pop3s started 2005.06.17 11:45:15 LOG7[10779:16386]: TCP_NODELAY option set on local socket 2005.06.17 11:45:15 LOG5[10779:16386]: pop3s connected from 172.16.203.52:2150 2005.06.17 11:45:15 LOG7[10779:16386]: SSL state (accept): before/accept initialization 2005.06.17 11:45:18 LOG3[10779:16386]: SSL_accept: Peer suddenly disconnected 2005.06.17 11:45:18 LOG7[10779:16386]: pop3s finished (0 left)