Hi,

I have found an issue when trying to monitor imaps and pop3s server offering TLS1.3 .

My xymon server configuration:

freebsd-version -u

12.0-RELEASE-p5

openssl version

OpenSSL 1.1.1a-freebsd 20 Nov 2018

standard freebsd xymon-server pkg :

pkg info xymon-server-4.3.28

xymon-server-4.3.28 Name : xymon-server Version : 4.3.28 Installed on : Fri Feb 22 14:19:11 2019 CET Origin : net-mgmt/xymon-server Architecture : FreeBSD:12:amd64 Prefix : /usr/local Categories : net-mgmt www Licenses : GPLv2 Maintainer : feld at FreeBSD.org WWW : http://xymon.sourceforge.net/ Comment : System for monitoring servers and networks Options : DEBUG : off LDAP : off NETSNMP : off Shared Libs required: libcares.so.2 libpng16.so.16 libpcre.so.1 librrd.so.8 Annotations : FreeBSD_version: 1200086 cpe : cpe:2.3:a:xymon:xymon:4.3.28:::::freebsd12:x64 repo_type : binary repository : FreeBSD Flat size : 26.5MiB ...

ldd /usr/local/www/xymon/server/bin/xymonnet

/usr/local/www/xymon/server/bin/xymonnet: libcares.so.2 => /usr/local/lib/libcares.so.2 (0x80027c000) libssl.so.111 => /usr/lib/libssl.so.111 (0x800297000) libcrypto.so.111 => /lib/libcrypto.so.111 (0x80032c000) libpcre.so.1 => /usr/local/lib/libpcre.so.1 (0x800619000) libc.so.7 => /lib/libc.so.7 (0x8006bd000) libthr.so.3 => /lib/libthr.so.3 (0x800ab0000)

When trying to monitor a pop3s or imaps server offering tls 1.3, I got random errors:

WARNING: Flapping status Service imaps on xxx is not OK : Unexpected service response

If I monitor the same services on an other server not offering tls 1.3, all is fine.

Both servers where running dovecot.

I wrote an extension in perl using IO::Socket::SSL (and the same local openssl) to monitor the server offerng tls 1.3 and all is fine with it.

For some strange reason, I can monitor a https web servers (running nginx or apache) offering TLS 1.3 without this issue but not imaps/pop3s.

It looks like the https test is different from other ssl/tls tests and does not have the TLS 1.3 issue

Regards,

Laurent Frigault | Free.org - BookMyName.com - ONLINE SAS - Registar ID 74