fail2ban/config/filter.d/dropbear.conf

# Fail2Ban filter for dropbear
#
# NOTE: The regex below is ONLY intended to work with a patched
# version of Dropbear as described here:
# http://www.unchartedbackwaters.co.uk/pyblosxom/static/patches
#            ^%(__prefix_line)sexit before auth from <HOST>.*\s*$
#
# The standard Dropbear output doesn't provide enough information to
# ban all types of attack.  The Dropbear patch adds IP address
# information to the 'exit before auth' message which is always
# produced for any form of non-successful login. It is that message
# which this file matches.
#
# More information: http://bugs.debian.org/546913

[INCLUDES]

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

[Definition]

_daemon = dropbear

failregex = ^%(__prefix_line)s[Ll]ogin attempt for nonexistent user ('.*' )?from <HOST>:\d+$
            ^%(__prefix_line)s[Bb]ad (PAM )?password attempt for .+ from <HOST>(:\d+)?$
            ^%(__prefix_line)s[Ee]xit before auth \(user '.+', \d+ fails\): Max auth tries reached - user '.+' from <HOST>:\d+\s*$

ignoreregex = 

# DEV Notes:
#
# The first two regexs here match the unmodified dropbear messages. It isn't
# possible to match the source of the 'exit before auth' messages from dropbear
# as they don't include the "from <HOST>" bit.
#
# The second last failregex line we need to match with the modified dropbear.
#
# For the second regex the following apply:
#
# http://www.netmite.com/android/mydroid/external/dropbear/svr-authpam.c
# http://svn.dd-wrt.com/changeset/16642#file64
#
# http://svn.dd-wrt.com/changeset/16642/src/router/dropbear/svr-authpasswd.c
#
# Author: Francis Russell
#         Zak B. Elep