From 747d4683221b5584f9663695fb48145689b42ceb Mon Sep 17 00:00:00 2001

From: sebres <info@sebres.de>

Date: Mon, 4 Jan 2021 02:42:38 +0100

Subject: [PATCH] fixes century selector of %ExY and %Exy in datepattern for

 tests, considering interval from 2005 (alternate now) to now; + better

 grouping algorithm for resulting century RE

---

 fail2ban/server/strptime.py | 24 ++++++++++++++++++++++--

 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/fail2ban/server/strptime.py b/fail2ban/server/strptime.py

index 1464a96d1f..39fc795865 100644

--- a/fail2ban/server/strptime.py

+++ b/fail2ban/server/strptime.py

@@ -36,10 +36,30 @@ def _getYearCentRE(cent=(0,3), distance=3, now=(MyTime.now(), MyTime.alternateNo

 	Thereby respect possible run in the test-cases (alternate date used there)

 	"""

 	cent = lambda year, f=cent[0], t=cent[1]: str(year)[f:t]

+	def grp(exprset):

+		c = None

+		if len(exprset) > 1:

+			for i in exprset:

+				if c is None or i[0:-1] == c:

+					c = i[0:-1]

+				else:

+					c = None

+					break

+			if not c:

+				for i in exprset:

+					if c is None or i[0] == c:

+						c = i[0]

+					else:

+						c = None

+						break

+			if c:

+				return "%s%s" % (c, grp([i[len(c):] for i in exprset]))

+		return ("(?:%s)" % "|".join(exprset) if len(exprset[0]) > 1 else "[%s]" % "".join(exprset)) \

+			if len(exprset) > 1 else "".join(exprset)

 	exprset = set( cent(now[0].year + i) for i in (-1, distance) )

 	if len(now) and now[1]:

-		exprset |= set( cent(now[1].year + i) for i in (-1, distance) )

-	return "(?:%s)" % "|".join(exprset) if len(exprset) > 1 else "".join(exprset)

+		exprset |= set( cent(now[1].year + i) for i in xrange(-1, now[0].year-now[1].year+1, distance) )

+	return grp(sorted(list(exprset)))

 timeRE = TimeRE()