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Merge pull request #1720 from sebres/_0.10/fix-gh-1719

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fix gh-1719: sshd format changed
pull/1725/head
Serg G. Brester 8 years ago committed by GitHub
parent 482e5265d7 5561423be3
commit da808fe67b
5 changed files with 45 additions and 27 deletions
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7
config/filter.d/sshd.conf
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@ -41,17 +41,18 @@ cmnfailre = ^[aA]uthentication (?:failure|error|failed) for <F-USER>.*</F-USER>
^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*)? \[preauth\]$
^(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
^Disconnecting: Too many authentication failures for <F-USER>.+?</F-USER>%(__suff)s
^Disconnecting: Too many authentication failures(?: for <F-USER>.+?</F-USER>)?%(__suff)s
^<F-NOFAIL>Received disconnect</F-NOFAIL> from <HOST>: 11:
^<F-NOFAIL>Connection closed</F-NOFAIL> by <HOST>%(__suff)s$
mdre-normal =
mdre-ddos = ^Did not receive identification string from <HOST>%(__suff)s$
^Connection reset 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 reset by peer \[preauth\]
^Read from socket failed: Connection reset by peer%(__suff)s
mdre-extra = ^Received disconnect 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 (?:cipher|key exchange method) found.

9
fail2ban/server/filter.py
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@ -183,15 +183,12 @@ class Filter(JailThread):
"valid", index)
##
# Get the regular expression which matches the failure.
# Get the regular expressions as list.
#
# @return the regular expression
# @return the regular expression list
def getFailRegex(self):
failRegex = list()
for regex in self.__failRegex:
failRegex.append(regex.getRegex())
return failRegex
return [regex.getRegex() for regex in self.__failRegex]
##
# Add the regular expression which matches the failure.

5
fail2ban/tests/config/filter.d/zzz-sshd-obsolete-multiline.conf
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@ -40,12 +40,13 @@ cmnfailre = ^%(__prefix_line_sl)s[aA]uthentication (?:failure|error|failed) for
^%(__prefix_line_sl)spam_unix\(sshd:auth\):\s+authentication failure;\s*logname=\S*\s*uid=\d*\s*euid=\d*\s*tty=\S*\s*ruser=\S*\s*rhost=<HOST>\s.*%(__suff)s$
^%(__prefix_line_sl)s(error: )?maximum authentication attempts exceeded for .* from <HOST>%(__on_port_opt)s(?: ssh\d*)? \[preauth\]$
^%(__prefix_line_ml1)sUser .+ not allowed because account is locked%(__prefix_line_ml2)sReceived disconnect from <HOST>: 11: .+%(__suff)s$
^%(__prefix_line_ml1)sDisconnecting: Too many authentication failures for .+?%(__prefix_line_ml2)sConnection closed by <HOST>%(__suff)s$
^%(__prefix_line_ml1)sConnection from <HOST>%(__on_port_opt)s%(__prefix_line_ml2)sDisconnecting: Too many authentication failures for .+%(__suff)s$
^%(__prefix_line_ml1)sDisconnecting: Too many authentication failures(?: for .+?)?%(__suff)s%(__prefix_line_ml2)sConnection closed by <HOST>%(__suff)s$
^%(__prefix_line_ml1)sConnection from <HOST>%(__on_port_opt)s%(__prefix_line_ml2)sDisconnecting: Too many authentication failures(?: for .+?)?%(__suff)s$
mdre-normal =
mdre-ddos = ^%(__prefix_line_sl)sDid not receive identification string from <HOST>%(__suff)s$
^%(__prefix_line_sl)sConnection reset by <HOST>%(__on_port_opt)s%(__suff)s
^%(__prefix_line_ml1)sSSH: Server;Ltype: (?:Authname|Version|Kex);Remote: <HOST>-\d+;[A-Z]\w+:.*%(__prefix_line_ml2)sRead from socket failed: Connection reset by peer%(__suff)s$
mdre-extra = ^%(__prefix_line_sl)sReceived disconnect from <HOST>%(__on_port_opt)s:\s*14: No supported authentication methods available%(__suff)s$

7
fail2ban/tests/files/logs/sshd
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@ -168,7 +168,7 @@ Feb 12 04:09:21 localhost sshd[26713]: Disconnecting: Too many authentication fa
# failJSON: { "match": false }
Feb 12 04:09:18 localhost sshd[26713]: Connection from 115.249.163.77 port 51353 on 127.0.0.1 port 22
# failJSON: { "time": "2005-02-12T04:09:21", "match": true , "host": "115.249.163.77", "desc": "Multiline match with interface address" }
Feb 12 04:09:21 localhost sshd[26713]: Disconnecting: Too many authentication failures for root [preauth]
Feb 12 04:09:21 localhost sshd[26713]: Disconnecting: Too many authentication failures [preauth]
# failJSON: { "time": "2004-11-23T21:50:37", "match": true , "host": "61.0.0.1", "desc": "New logline format as openssh 6.8 to replace prev multiline version" }
Nov 23 21:50:37 myhost sshd[21810]: error: maximum authentication attempts exceeded for root from 61.0.0.1 port 49940 ssh2 [preauth]
@ -208,6 +208,11 @@ Nov 24 23:46:41 host sshd[32686]: SSH: Server;Ltype: Authname;Remote: 127.0.0.1-
# failJSON: { "time": "2004-11-24T23:46:43", "match": true , "host": "127.0.0.1", "desc": "Multiline for connection reset by peer (3)" }
Nov 24 23:46:43 host sshd[32686]: fatal: Read from socket failed: Connection reset by peer [preauth]
# gh-1719:
# failJSON: { "time": "2005-03-15T09:20:57", "match": true , "host": "192.0.2.39", "desc": "Singleline for connection reset by" }
Mar 15 09:20:57 host sshd[28972]: Connection reset by 192.0.2.39 port 14282 [preauth]
# filterOptions: {"mode": "extra"}
# several other cases from gh-864:

44
fail2ban/tests/samplestestcase.py
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@ -99,8 +99,8 @@ class FilterSamplesRegex(unittest.TestCase):
optval = opt[3]
elif opt[0] == 'set':
optval = [opt[3]]
else:
continue
else: # pragma: no cover - unexpected
self.fail('Unexpected config-token %r in stream' % (opt,))
for optval in optval:
if opt[2] == "prefregex":
self.filter.prefRegex = optval
@ -115,11 +115,13 @@ class FilterSamplesRegex(unittest.TestCase):
# test regexp contains greedy catch-all before <HOST>, that is
# not hard-anchored at end or has not precise sub expression after <HOST>:
for fr in self.filter.getFailRegex():
regexList = self.filter.getFailRegex()
for fr in regexList:
if RE_WRONG_GREED.search(fr): # pragma: no cover
raise AssertionError("Following regexp of \"%s\" contains greedy catch-all before <HOST>, "
"that is not hard-anchored at end or has not precise sub expression after <HOST>:\n%s" %
(name, str(fr).replace(RE_HOST, '<HOST>')))
return regexList
def testSampleRegexsFactory(name, basedir):
def testFilter(self):
@ -128,8 +130,17 @@ def testSampleRegexsFactory(name, basedir):
os.path.isfile(os.path.join(TEST_FILES_DIR, "logs", name)),
"No sample log file available for '%s' filter" % name)
regexsUsed = set()
regexList = None
regexsUsedIdx = set()
regexsUsedRe = set()
filenames = [name]
def _testMissingSamples():
for failRegexIndex, failRegex in enumerate(regexList):
self.assertTrue(
failRegexIndex in regexsUsedIdx or failRegex in regexsUsedRe,
"Regex for filter '%s' has no samples: %i: %r" %
(name, failRegexIndex, failRegex))
i = 0
while i < len(filenames):
filename = filenames[i]; i += 1;
@ -143,25 +154,30 @@ def testSampleRegexsFactory(name, basedir):
faildata = json.loads(jsonREMatch.group(2))
# filterOptions - dict in JSON to control filter options (e. g. mode, etc.):
if jsonREMatch.group(1) == 'filterOptions':
# another filter mode - we should check previous also:
if self.filter is not None:
_testMissingSamples()
regexsUsedIdx = set() # clear used indices (possible overlapping by mode change)
# read filter with another setting:
self.filter = None
self._readFilter(name, basedir, opts=faildata)
regexList = self._readFilter(name, basedir, opts=faildata)
continue
# addFILE - filename to "include" test-files should be additionally parsed:
if jsonREMatch.group(1) == 'addFILE':
filenames.append(faildata)
continue
# failJSON - faildata contains info of the failure to check it.
except ValueError as e:
except ValueError as e: # pragma: no cover - we've valid json's
raise ValueError("%s: %s:%i" %
(e, logFile.filename(), logFile.filelineno()))
line = next(logFile)
elif line.startswith("#") or not line.strip():
continue
else:
else: # pragma: no cover - normally unreachable
faildata = {}
if self.filter is None:
self._readFilter(name, basedir, opts=None)
regexList = self._readFilter(name, basedir, opts=None)
try:
ret = self.filter.processLine(line)
@ -174,7 +190,8 @@ def testSampleRegexsFactory(name, basedir):
failregex, fid, fail2banTime, fail = ret[0]
# Bypass no failure helpers-regexp:
if not faildata.get('match', False) and (fid is None or fail.get('nofail')):
regexsUsed.add(failregex)
regexsUsedIdx.add(failregex)
regexsUsedRe.add(regexList[failregex])
continue
# Check line is flagged to match
@ -208,16 +225,13 @@ def testSampleRegexsFactory(name, basedir):
jsonTime, time.strftime("%Y-%m-%dT%H:%M:%S", time.gmtime(jsonTime)),
fail2banTime - jsonTime) )
regexsUsed.add(failregex)
regexsUsedIdx.add(failregex)
regexsUsedRe.add(regexList[failregex])
except AssertionError as e: # pragma: no cover
raise AssertionError("%s on: %s:%i, line:\n%s" % (
e, logFile.filename(), logFile.filelineno(), line))
for failRegexIndex, failRegex in enumerate(self.filter.getFailRegex()):
self.assertTrue(
failRegexIndex in regexsUsed,
"Regex for filter '%s' has no samples: %i: %r" %
(name, failRegexIndex, failRegex))
_testMissingSamples()
return testFilter

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