fail2ban - sshd

moin,
hast du ein jail.local?

[pure-ftpd]
enabled = true
port = ftp
filter = pure-ftpd
logpath = /var/log/syslog
maxretry = 3

[dovecot]
enabled = true
filter = dovecot
action = iptables-multiport[name=dovecot-pop3imap, port="pop3,pop3s,imap,imaps", protocol=tcp]
logpath = /var/log/mail.log
maxretry = 5

[postfix]
enabled = true
port = smtp
filter = postfix
logpath = /var/log/mail.log
maxretry = 3

[ssh]

enabled = true
port = ssh
filter = sshd
logpath = /var/log/auth.log
maxretry = 5

Das ganze wird dann auch in den Logs gefiltert. Da denke ich ist dein Problem.

Filter.d für SSHD sieht so aus:

# Fail2Ban filter for openssh
#
# If you want to protect OpenSSH from being bruteforced by password
# authentication then get public key authentication working before disabling
# PasswordAuthentication in sshd_config.
#
#
# "Connection from <HOST> port \d+" requires LogLevel VERBOSE in sshd_config
#

[INCLUDES]

# Read common prefixes. If any customizations available -- read them from
# common.local
before = common.conf

[DEFAULT]

_daemon = sshd

# optional prefix (logged from several ssh versions) like "error: ", "error: PAM: " or "fatal: "
__pref = (?:(?:error|fatal): (?:PAM: )?)?
# optional suffix (logged from several ssh versions) like " [preauth]"
__suff = (?: \[preauth\])?\s*
__on_port_opt = (?: port \d+)?(?: on \S+(?: port \d+)?)?

# for all possible (also future) forms of "no matching (cipher|mac|MAC|compression method|key exchange method|host key type) found",
# see ssherr.c for all possible SSH_ERR_..._ALG_MATCH errors.
__alg_match = (?:(?:\w+ (?!found\b)){0,2}\w+)

[Definition]

prefregex = ^<F-MLFID>%(__prefix_line)s</F-MLFID>%(__pref)s<F-CONTENT>.+</F-CONTENT>$

cmnfailre = ^[aA]uthentication (?:failure|error|failed) for <F-USER>.*</F-USER> from <HOST>( via \S+)?\s*%(__suff)s$
^User not known to the underlying authentication module for <F-USER>.*</F-USER> from <HOST>\s*%(__suff)s$
^Failed \S+ for invalid user <F-USER>(?P<cond_user>\S+)|(?:(?! from ).)*?</F-USER> from <HOST>%(__on_port_opt)s(?: ssh\d*)?(?(cond_user): |(?:(?:(?! from ).)*)$)
^Failed \b(?!publickey)\S+ for (?P<cond_inv>invalid user )?<F-USER>(?P<cond_user>\S+)|(?(cond_inv)(?:(?! from ).)*?|[^:]+)</F-USER> from <HOST>%(__on_port_opt)s(?: ssh\d*)?(?(cond_user): |(?:(?:(?! from ).)*)$)
^<F-USER>ROOT</F-USER> LOGIN REFUSED.* FROM <HOST>\s*%(__suff)s$
^[iI](?:llegal|nvalid) user <F-USER>.*?</F-USER> from <HOST>%(__on_port_opt)s\s*$
^User <F-USER>.+</F-USER> from <HOST> not allowed because not listed in AllowUsers\s*%(__suff)s$
^User <F-USER>.+</F-USER> from <HOST> not allowed because listed in DenyUsers\s*%(__suff)s$
^User <F-USER>.+</F-USER> from <HOST> not allowed because not in any group\s*%(__suff)s$
^refused connect from \S+ \(<HOST>\)\s*%(__suff)s$
^Received <F-MLFFORGET>disconnect</F-MLFFORGET> from <HOST>%(__on_port_opt)s:\s*3: .*: Auth fail%(__suff)s$
^User <F-USER>.+</F-USER> from <HOST> not allowed because a group is listed in DenyGroups\s*%(__suff)s$
^User <F-USER>.+</F-USER> from <HOST> not allowed because none of user's groups are listed in AllowGroups\s*%(__suff)s$
^pam_unix\(sshd:auth\):\s+authentication failure;\s*logname=\S*\s*uid=\d*\s*euid=\d*\s*tty=\S*\s*ruser=<F-USER>\S*</F-USER>\s*rhost=<HOST>\s.*%(__suff)s$
^(error: )?maximum authentication attempts exceeded for <F-USER>.*</F-USER> from <HOST>%(__on_port_opt)s(?: ssh\d*)?%(__suff)s$
^User <F-USER>.+</F-USER> not allowed because account is locked%(__suff)s
^<F-MLFFORGET>Disconnecting</F-MLFFORGET>: Too many authentication failures(?: for <F-USER>.+?</F-USER>)?%(__suff)s
^<F-NOFAIL>Received <F-MLFFORGET>disconnect</F-MLFFORGET></F-NOFAIL> from <HOST>: 11:
^<F-NOFAIL>Connection <F-MLFFORGET>closed</F-MLFFORGET></F-NOFAIL> by <HOST>%(__suff)s$
^<F-MLFFORGET><F-NOFAIL>Accepted publickey</F-NOFAIL></F-MLFFORGET> for \S+ from <HOST>(?:\s|$)

mdre-normal =

mdre-ddos = ^Did not receive identification string from <HOST>%(__suff)s$
^Connection <F-MLFFORGET>reset</F-MLFFORGET> by <HOST>%(__on_port_opt)s%(__suff)s
^<F-NOFAIL>SSH: Server;Ltype:</F-NOFAIL> (?:Authname|Version|Kex);Remote: <HOST>-\d+;[A-Z]\w+:
^Read from socket failed: Connection <F-MLFFORGET>reset</F-MLFFORGET> by peer%(__suff)s

mdre-extra = ^Received <F-MLFFORGET>disconnect</F-MLFFORGET> from <HOST>%(__on_port_opt)s:\s*14: No supported authentication methods available%(__suff)s$
^Unable to negotiate with <HOST>%(__on_port_opt)s: no matching <__alg_match> found.
^Unable to negotiate a <__alg_match>%(__suff)s$
^no matching <__alg_match> found:

mdre-aggressive = %(mdre-ddos)s
%(mdre-extra)s

cfooterre = ^<F-NOFAIL>Connection from</F-NOFAIL> <HOST>

failregex = %(cmnfailre)s
<mdre-<mode>>
%(cfooterre)s

# Parameter "mode": normal (default), ddos, extra or aggressive (combines all)
# Usage example (for jail.local):
# [sshd]
# mode = extra
# # or another jail (rewrite filter parameters of jail):
# [sshd-aggressive]
# filter = sshd[mode=aggressive]
#
mode = normal

#filter = sshd[mode=aggressive]

ignoreregex =

maxlines = 1

journalmatch = _SYSTEMD_UNIT=sshd.service + _COMM=sshd

datepattern = {^LN-BEG}

# DEV Notes:
#
# "Failed \S+ for .*? from <HOST>..." failregex uses non-greedy catch-all because
# it is coming before use of <HOST> which is not hard-anchored at the end as well,
# and later catch-all's could contain user-provided input, which need to be greedily
# matched away first.
#
# Author: Cyril Jaquier, Yaroslav Halchenko, Petr Voralek, Daniel Black and Sergey Brester aka sebres
# Rewritten using prefregex (and introduced "mode" parameter) by Serg G. Brester.