I can confirm I am also experiencing this issue on 18.04.
stunnel4 -v [ ] Clients allowed=500 [.] stunnel 5.44 on x86_64-pc-linux-gnu platform [.] Compiled with OpenSSL 1.1.0g 2 Nov 2017 [.] Running with OpenSSL 1.1.1b 26 Feb 2019 [.] Update OpenSSL shared libraries or rebuild stunnel [.] Threading:PTHREAD Sockets:POLL,IPv6,SYSTEMD TLS:ENGINE,FIPS,OCSP,PSK,SNI Auth:LIBWRAP [ ] errno: (*__errno_location ()) [!] Invalid configuration file name "-v" [!] realpath: No such file or directory (2)
$ sudo more stunnel.log.1 2019.10.25 05:06:34 LOG3[217]: TLS socket closed (SSL_write) with 18432 unsent byte(s) 2019.10.25 05:25:04 LOG3[221]: TLS socket closed (SSL_write) with 2274 unsent byte(s) 2019.10.25 06:21:56 LOG3[231]: TLS socket closed (SSL_write) with 6993 unsent byte(s) 2019.10.25 06:39:36 LOG3[233]: TLS socket closed (SSL_read) with 15138 unsent byte(s) 2019.10.25 07:59:49 LOG3[241]: TLS socket closed (SSL_write) with 18432 unsent byte(s) 2019.10.25 08:22:01 LOG3[243]: TLS socket closed (SSL_write) with 1117 unsent byte(s) 2019.10.25 08:37:57 LOG3[245]: TLS socket closed (SSL_write) with 1591 unsent byte(s) 2019.10.25 09:37:20 LOG3[251]: TLS socket closed (SSL_write) with 18432 unsent byte(s) 2019.10.25 09:50:53 LOG3[253]: TLS socket closed (SSL_write) with 11950 unsent byte(s) INTERNAL ERROR: Bad magic at ssl.c, line 117
I do not know any history of when the bug started, I only recently set up stunnel in the last couple months.
I can confirm I am also experiencing this issue on 18.04.
stunnel4 -v POLL,IPv6, SYSTEMD TLS:ENGINE, FIPS,OCSP, PSK,SNI Auth:LIBWRAP
[ ] Clients allowed=500
[.] stunnel 5.44 on x86_64-pc-linux-gnu platform
[.] Compiled with OpenSSL 1.1.0g 2 Nov 2017
[.] Running with OpenSSL 1.1.1b 26 Feb 2019
[.] Update OpenSSL shared libraries or rebuild stunnel
[.] Threading:PTHREAD Sockets:
[ ] errno: (*__errno_location ())
[!] Invalid configuration file name "-v"
[!] realpath: No such file or directory (2)
$ sudo more stunnel.log.1
2019.10.25 05:06:34 LOG3[217]: TLS socket closed (SSL_write) with 18432 unsent byte(s)
2019.10.25 05:25:04 LOG3[221]: TLS socket closed (SSL_write) with 2274 unsent byte(s)
2019.10.25 06:21:56 LOG3[231]: TLS socket closed (SSL_write) with 6993 unsent byte(s)
2019.10.25 06:39:36 LOG3[233]: TLS socket closed (SSL_read) with 15138 unsent byte(s)
2019.10.25 07:59:49 LOG3[241]: TLS socket closed (SSL_write) with 18432 unsent byte(s)
2019.10.25 08:22:01 LOG3[243]: TLS socket closed (SSL_write) with 1117 unsent byte(s)
2019.10.25 08:37:57 LOG3[245]: TLS socket closed (SSL_write) with 1591 unsent byte(s)
2019.10.25 09:37:20 LOG3[251]: TLS socket closed (SSL_write) with 18432 unsent byte(s)
2019.10.25 09:50:53 LOG3[253]: TLS socket closed (SSL_write) with 11950 unsent byte(s)
INTERNAL ERROR: Bad magic at ssl.c, line 117
I do not know any history of when the bug started, I only recently set up stunnel in the last couple months.