Skip to content
Snippets Groups Projects
Commit e0f58cce authored by Stuart Gathman's avatar Stuart Gathman
Browse files

Merge changes from pyspf to pass test suite.

parent 157f33ed
Branches
Tags
No related merge requests found
......@@ -2,8 +2,8 @@
"""SPF (Sender Policy Framework) implementation.
Copyright (c) 2003, Terence Way
Portions Copyright (c) 2004,2005,2006 Stuart Gathman <stuart@bmsi.com>
Portions Copyright (c) 2005,2006 Scott Kitterman <scott@kitterman.com>
Portions Copyright (c) 2004,2005 Stuart Gathman <stuart@bmsi.com>
Portions Copyright (c) 2005 Scott Kitterman <scott@kitterman.com>
This module is free software, and you may redistribute it and/or modify
it under the same terms as Python itself, so long as this copyright message
and disclaimer are retained in their original form.
......@@ -48,6 +48,9 @@ For news, bugfixes, etc. visit the home page for this implementation at
# Terrence is not responding to email.
#
# $Log$
# Revision 1.25 2006/07/31 15:25:39 customdesigned
# Permerror for multiple TXT SPF records.
#
# Revision 1.24 2006/07/28 01:21:33 customdesigned
# Remove debug print
#
......@@ -334,7 +337,7 @@ def isSPF(txt):
MASK = 0xFFFFFFFFL
# Regular expression to look for modifiers
RE_MODIFIER = re.compile(r'^([a-zA-Z0-9_\-\.]+)=')
RE_MODIFIER = re.compile(r'^([a-z][a-z0-9_\-\.]*)=',re.IGNORECASE)
# Regular expression to find macro expansions
RE_CHAR = re.compile(r'%(%|_|-|(\{[a-zA-Z][0-9]*r?[^\}]*\}))')
......@@ -342,10 +345,28 @@ RE_CHAR = re.compile(r'%(%|_|-|(\{[a-zA-Z][0-9]*r?[^\}]*\}))')
# Regular expression to break up a macro expansion
RE_ARGS = re.compile(r'([0-9]*)(r?)([^0-9a-zA-Z]*)')
RE_CIDR = re.compile(r'/([1-9]|1[0-9]|2[0-9]|3[0-2])$')
RE_IP4 = re.compile(r'\.'.join(
[r'(?:\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])']*4)+'$')
RE_DUAL_CIDR = re.compile(r'//(0|[1-9]\d*)$')
RE_CIDR = re.compile(r'/(0|[1-9]\d*)$')
PAT_IP4 = r'\.'.join([r'(?:\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])']*4)
RE_IP4 = re.compile(PAT_IP4+'$')
RE_TOPLAB = re.compile(
r'\.[0-9a-z]*[a-z][0-9a-z]*|[0-9a-z]+-[0-9a-z-]*[0-9a-z]$',re.IGNORECASE)
RE_IP6 = re.compile( '(?:%(hex4)s:){6}%(ls32)s$'
'|::(?:%(hex4)s:){5}%(ls32)s$'
'|(?:%(hex4)s)?::(?:%(hex4)s:){4}%(ls32)s$'
'|(?:(?:%(hex4)s:){0,1}%(hex4)s)?::(?:%(hex4)s:){3}%(ls32)s$'
'|(?:(?:%(hex4)s:){0,2}%(hex4)s)?::(?:%(hex4)s:){2}%(ls32)s$'
'|(?:(?:%(hex4)s:){0,3}%(hex4)s)?::%(hex4)s:%(ls32)s$'
'|(?:(?:%(hex4)s:){0,4}%(hex4)s)?::%(ls32)s$'
'|(?:(?:%(hex4)s:){0,5}%(hex4)s)?::%(hex4)s$'
'|(?:(?:%(hex4)s:){0,6}%(hex4)s)?::$'
% {
'ls32': r'(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|%s)'%PAT_IP4,
'hex4': r'[0-9a-f]{1,4}'
}, re.IGNORECASE)
# Local parts and senders have their delimiters replaced with '.' during
# macro expansion
......@@ -353,18 +374,55 @@ RE_IP4 = re.compile(r'\.'.join(
JOINERS = {'l': '.', 's': '.'}
RESULTS = {'+': 'pass', '-': 'fail', '?': 'neutral', '~': 'softfail',
'pass': 'pass', 'fail': 'fail', 'unknown': 'unknown',
'pass': 'pass', 'fail': 'fail', 'permerror': 'permerror',
'error': 'error', 'neutral': 'neutral', 'softfail': 'softfail',
'none': 'none', 'deny': 'fail' }
EXPLANATIONS = {'pass': 'sender SPF verified', 'fail': 'access denied',
'unknown': 'permanent error in processing',
'error': 'temporary error in processing',
'softfail': 'domain in transition',
'none': 'none', 'local': 'local', 'trusted': 'trusted',
'ambiguous': 'ambiguous'}
EXPLANATIONS = {'pass': 'sender SPF authorized',
'fail': 'SPF fail - not authorized',
'permerror': 'permanent error in processing',
'temperror': 'temporary DNS error in processing',
'softfail': 'domain owner discourages use of this host',
'neutral': 'access neither permitted nor denied',
'none': ''
'none': '',
#Note: The following are not formally SPF results
'local': 'No SPF result due to local policy',
'trusted': 'No SPF check - trusted-forwarder.org',
#Ambiguous only used in harsh mode for SPF validation
'ambiguous': 'No error, but results may vary'
}
#Default receiver policies - can be overridden.
POLICY = {'tfwl': False, #Check trusted-forwarder.org
'skip_localhost': True, #Don't check SPF on local connections
'always_helo': False, #Only works if helo_first is also True.
'spf_helo_mustpass': True, #Treat HELO test returning softfail or
#neutral as Fail - HELO should be a single IP per name. No reason to
#accept SPF relaxed provisions for HELO. No affect if None.
'reject_helo_fail': False,
'spf_reject_fail': True,
'spf_reject_neutral': False,
'spf_accept_softfail': True,
'spf_best_guess': True,
'spf_strict': True,
}
# Recommended SMTP codes for certain SPF results. For results not in
# this table the recommendation is to accept the message as authorized.
# An SPF result is never enough to recommend that a message be accepted for
# delivery. Additional checks are generally required.
# The softfail result requires special processing.
SMTP_CODES = {
'fail': [550,'5.7.1'],
'temperror': [451,'4.4.3'],
'permerror': [550,'5.5.2'],
'softfail': [451,'4.3.0']
}
if not POLICY['spf_accept_softfail']:
SMTP_CODES['softfail'] = (550,'5.7.1')
if POLICY['spf_reject_neutral']:
SMTP_CODES['neutral'] = (550,'5.7.1')
# if set to a domain name, search _spf.domain namespace if no SPF record
# found in source domain.
......@@ -381,17 +439,46 @@ except NameError:
# standard default SPF record for best_guess
DEFAULT_SPF = 'v=spf1 a/24 mx/24 ptr'
#Whitelisted forwarders here. Additional locally trusted forwarders can be
#added to this record.
TRUSTED_FORWARDERS = 'v=spf1 ?include:spf.trusted-forwarder.org -all'
# maximum DNS lookups allowed
MAX_LOOKUP = 10 #RFC 4408 Para 10.1
MAX_MX = 10 #RFC 4408 Para 10.1
MAX_PTR = 10 #RFC 4408 Para 10.1
MAX_CNAME = 10 # analogous interpretation to MAX_PTR
MAX_RECURSION = 20
ALL_MECHANISMS = ('a', 'mx', 'ptr', 'exists', 'include', 'ip4', 'ip6', 'all')
COMMON_MISTAKES = { 'prt': 'ptr', 'ip': 'ip4', 'ipv4': 'ip4', 'ipv6': 'ip6' }
#If harsh processing, for the validator, is invoked, warn if results
#likely deviate from the publishers intention.
class AmbiguityWarning(Exception):
"SPF Warning - ambiguous results"
def __init__(self,msg,mech=None,ext=None):
Exception.__init__(self,msg,mech)
self.msg = msg
self.mech = mech
self.ext = ext
def __str__(self):
if self.mech:
return '%s: %s'%(self.msg,self.mech)
return self.msg
class TempError(Exception):
"Temporary SPF error"
def __init__(self,msg,mech=None,ext=None):
Exception.__init__(self,msg,mech)
self.msg = msg
self.mech = mech
self.ext = ext
def __str__(self):
if self.mech:
return '%s: %s'%(self.msg,self.mech)
return self.msg
class PermError(Exception):
"Permanent SPF error"
......@@ -409,13 +496,10 @@ def check(i, s, h,local=None,receiver=None):
"""Test an incoming MAIL FROM:<s>, from a client with ip address i.
h is the HELO/EHLO domain name.
Returns (result, mta-status-code, explanation) where result in
['pass', 'unknown', 'fail', 'error', 'softfail', 'none', 'neutral' ].
Returns (result, code, explanation) where result in
['pass', 'permerror', 'fail', 'temperror', 'softfail', 'none', 'neutral' ].
Example:
>>> check(i='127.0.0.1', s='terry@wayforward.net', h='localhost')
('pass', 250, 'local connections always pass')
#>>> check(i='61.51.192.42', s='liukebing@bcc.com', h='bmsi.com')
"""
......@@ -451,17 +535,22 @@ class query(object):
self.p = None
if receiver:
self.r = receiver
else:
self.r = 'unknown'
# Since the cache does not track Time To Live, it is created
# fresh for each query. It is important for efficiently using
# multiple results provided in DNS answers.
self.cache = {}
self.defexps = dict(EXPLANATIONS)
self.exps = dict(EXPLANATIONS)
self.local = local # local policy
self.libspf_local = local # local policy
self.lookups = 0
# strict can be False, True, or 2 for harsh
# strict can be False, True, or 2 (numeric) for harsh
self.strict = strict
self.perm_error = None
def set_default_explanation(self,exp):
exps = self.exps
for i in 'softfail','fail','unknown':
for i in 'softfail','fail','permerror':
exps[i] = exp
def getp(self):
......@@ -477,10 +566,11 @@ class query(object):
"""Return a best guess based on a default SPF record"""
return self.check(spf)
def check(self, spf=None):
"""
Returns (result, mta-status-code, explanation) where result
in ['fail', 'softfail', 'neutral' 'unknown', 'pass', 'error', 'none']
in ['fail', 'softfail', 'neutral' 'permerror', 'pass', 'temperror', 'none']
Examples:
>>> q = query(s='strong-bad@email.example.com',
......@@ -489,34 +579,42 @@ class query(object):
('neutral', 250, 'access neither permitted nor denied')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ?all moo')
('unknown', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
('permerror', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.check(spf='v=spf1 =a ?all moo')
('unknown', 550, 'SPF Permanent Error: Unknown qualifier, RFC 4408 para 4.6.1, found in: =a')
('permerror', 550, 'SPF Permanent Error: Unknown qualifier, RFC 4408 para 4.6.1, found in: =a')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 ~all')
('pass', 250, 'sender SPF verified')
('pass', 250, 'sender SPF authorized')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 -all moo=')
('pass', 250, 'sender SPF authorized')
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 -all match.sub-domains_9=yes')
('pass', 250, 'sender SPF authorized')
>>> q.strict = False
>>> q.check(spf='v=spf1 ip4:192.0.0.0/8 -all moo')
('unknown', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.perm_error.ext
('pass', 250, 'sender SPF verified')
('pass', 250, 'sender SPF authorized')
>>> q.check(spf='v=spf1 ip4:192.1.0.0/16 moo -all')
('unknown', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> str(q.perm_error.ext)
'None'
('permerror', 550, 'SPF Permanent Error: Unknown mechanism found: moo')
>>> q.check(spf='v=spf1 ip4:192.1.0.0/16 ~all')
('softfail', 250, 'domain in transition')
('softfail', 250, 'domain owner discourages use of this host')
>>> q.check(spf='v=spf1 -ip4:192.1.0.0/6 ~all')
('fail', 550, 'access denied')
('fail', 550, 'SPF fail - not authorized')
# Assumes DNS available
>>> q.check()
('none', 250, '')
>>> q.check(spf='v=spf1 ip4:1.2.3.4 -a:example.net -all')
('fail', 550, 'SPF fail - not authorized')
>>> q.libspf_local='ip4:192.0.2.3 a:example.org'
>>> q.check(spf='v=spf1 ip4:1.2.3.4 -a:example.net -all')
('pass', 250, 'sender SPF authorized')
"""
self.mech = [] # unknown mechanisms
# If not strict, certain PermErrors (mispelled
......@@ -524,23 +622,20 @@ class query(object):
# will continue processing. However, the exception
# that strict processing would raise is saved here
self.perm_error = None
if self.i.startswith('127.'):
return ('pass', 250, 'local connections always pass')
try:
self.lookups = 0
if not spf:
spf = self.dns_spf(self.d)
if self.local and spf:
spf += ' ' + self.local
rc = self.check1(spf, self.d, 0)
if self.perm_error:
# extended processing succeeded, but strict failed
self.perm_error.ext = rc
raise self.perm_error
return rc
if self.libspf_local and spf:
spf = insert_libspf_local_policy(
spf,self.libspf_local)
return self.check1(spf, self.d, 0)
except TempError,x:
return ('error', 450, 'SPF Temporary Error: ' + str(x))
self.prob = x.msg
if x.mech:
self.mech.append(x.mech)
return ('temperror',451, 'SPF Temporary Error: ' + str(x))
except PermError,x:
if not self.perm_error:
self.perm_error = x
......@@ -549,7 +644,7 @@ class query(object):
self.mech.append(x.mech)
# Pre-Lentczner draft treats this as an unknown result
# and equivalent to no SPF record.
return ('unknown', 550, 'SPF Permanent Error: ' + str(x))
return ('permerror', 550, 'SPF Permanent Error: ' + str(x))
def check1(self, spf, domain, recursion):
# spf rfc: 3.7 Processing Limits
......@@ -565,11 +660,17 @@ class query(object):
# As an extended result, however, it should be
# a PermError.
raise PermError('Too many levels of recursion')
try:
try:
tmp, self.d = self.d, domain
return self.check0(spf,recursion)
finally:
self.d = tmp
except AmbiguityWarning,x:
self.prob = x.msg
if x.mech:
self.mech.append(x.mech)
return ('ambiguous', 000, 'SPF Ambiguity Warning: %s' % x)
def note_error(self,*msg):
if self.strict:
......@@ -579,6 +680,8 @@ class query(object):
try:
raise PermError(*msg)
except PermError, x:
# FIXME: keep a list of errors for even friendlier
# diagnostics.
self.perm_error = x
return self.perm_error
......@@ -602,11 +705,11 @@ class query(object):
>>> try: q.validate_mechanism('ip4:1.2.3.4/247')
... except PermError,x: print x
Invalid IP4 address: ip4:1.2.3.4/247
Invalid IP4 CIDR length: ip4:1.2.3.4/247
>>> try: q.validate_mechanism('a:example.com:8080')
... except PermError,x: print x
Too many :. Not allowed in domain name.: a:example.com:8080
Invalid domain found (use FQDN): example.com:8080
>>> try: q.validate_mechanism('ip4:1.2.3.444/24')
... except PermError,x: print x
......@@ -621,10 +724,13 @@ class query(object):
>>> q.validate_mechanism('~exists:%{i}.%{s1}.100/86400.rate.%{d}')
('~exists:%{i}.%{s1}.100/86400.rate.%{d}', 'exists', '192.0.2.3.com.100/86400.rate.email.example.com', 32, 'softfail')
>>> q.validate_mechanism('a:mail.example.com.')
('a:mail.example.com.', 'a', 'mail.example.com', 32, 'pass')
"""
# a mechanism
m, arg, cidrlength = parse_mechanism(mech, self.d)
# map '?' '+' or '-' to 'unknown' 'pass' or 'fail'
m, arg, cidrlength, cidr6length = parse_mechanism(mech, self.d)
# map '?' '+' or '-' to 'neutral' 'pass' or 'fail'
if m:
result = RESULTS.get(m[0])
if result:
......@@ -641,34 +747,56 @@ class query(object):
x = self.note_error(
'Use the ip4 mechanism for ip4 addresses',mech)
m = 'ip4'
# Check for : within the arguement
if arg.count(':') > 0:
raise PermError('Too many :. Not allowed in domain name.',mech)
# validate cidr and dual-cidr
if m in ('a', 'mx', 'ptr'):
if cidrlength is None:
cidrlength = 32;
elif cidrlength > 32:
raise PermError('Invalid IP4 CIDR length',mech)
if cidr6length is None:
cidr6length = 128
elif cidr6length > 128:
raise PermError('Invalid IP6 CIDR length',mech)
elif m == 'ip4':
if cidr6length is not None:
raise PermError('Dual CIDR not allowed',mech)
if cidrlength is None:
cidrlength = 32;
elif cidrlength > 32:
raise PermError('Invalid IP4 CIDR length',mech)
if not RE_IP4.match(arg):
raise PermError('Invalid IP4 address',mech)
elif m == 'ip6':
if cidr6length is not None:
raise PermError('Dual CIDR not allowed',mech)
if cidrlength is None:
cidrlength = 128
elif cidrlength > 128:
raise PermError('Invalid IP6 CIDR length',mech)
if not RE_IP6.match(arg):
raise PermError('Invalid IP6 address',mech)
else:
if cidrlength is not None or cidr6length is not None:
raise PermError('Dual CIDR not allowed',mech)
cidrlength = 32
# validate domain-spec
if m in ('a', 'mx', 'ptr', 'exists', 'include'):
arg = self.expand(arg)
# FQDN must contain at least one '.'
pos = arg.rfind('.')
if not (0 < pos < len(arg) - 1):
raise PermError('Invalid domain found (use FQDN)',
arg)
#Test for all numeric TLD as recommended by RFC 3696
#Note this TLD test may pass non-existant TLDs. 3696
#recommends using DNS lookups to test beyond this
#initial test.
if arg[pos+1:].isdigit():
raise PermError('Top Level Domain may not be all numbers',
arg)
# any trailing dot was removed by expand()
if RE_TOPLAB.split(arg)[-1]:
raise PermError('Invalid domain found (use FQDN)', arg)
if m == 'include':
if arg == self.d:
if mech != 'include':
raise PermError('include has trivial recursion',mech)
raise PermError('include mechanism missing domain',mech)
return mech,m,arg,cidrlength,result
if m == 'ip4' and not RE_IP4.match(arg):
raise PermError('Invalid IP4 address',mech)
# validate 'all' mechanism per RFC 4408 ABNF
if m == 'all' and \
(arg != self.d or mech.count(':') or mech.count('/')):
if m == 'all' and mech.count(':'):
# print '|'+ arg + '|', mech, self.d,
self.note_error(
'Invalid all mechanism format - only qualifier allowed with all'
......@@ -694,7 +822,7 @@ class query(object):
# split string by whitespace, drop the 'v=spf1'
spf = spf.split()
# Catch case where SPF record has no spaces
# Catch case where SPF record has no spaces.
# Can never happen with conforming dns_spf(), however
# in the future we might want to give permerror
# for common mistakes like IN TXT "v=spf1" "mx" "-all"
......@@ -756,8 +884,13 @@ class query(object):
elif m == 'exists':
self.check_lookups()
try:
if len(self.dns_a(arg)) > 0:
break
except AmbiguityWarning:
# Exists wants no response sometimes so don't raise
# the warning.
pass
elif m == 'a':
self.check_lookups()
......@@ -769,7 +902,10 @@ class query(object):
if cidrmatch(self.i, self.dns_mx(arg), cidrlength):
break
elif m == 'ip4' and arg != self.d:
elif m == 'ip4':
if arg == self.d:
raise PermError('Missing IP4 arg',mech)
try:
if cidrmatch(self.i, [arg], cidrlength):
break
......@@ -777,6 +913,8 @@ class query(object):
raise PermError('syntax error',mech)
elif m == 'ip6':
if arg == self.d:
raise PermError('Missing IP6 arg',mech)
# Until we support IPV6, we should never
# get an IPv6 connection. So this mech
# will never match.
......@@ -792,8 +930,13 @@ class query(object):
else:
# no matches
if redirect:
return self.check1(self.dns_spf(redirect),
redirect, recursion + 1)
#Catch redirect to a non-existant SPF record.
redirect_record = self.dns_spf(redirect)
if not redirect_record:
raise PermError('redirect domain has no SPF record',
redirect)
return self.check1(redirect_record, redirect,
recursion + 1)
else:
result = default
......@@ -882,9 +1025,6 @@ class query(object):
>>> q.expand('%{p2}.trusted-domains.example.net')
'example.org.trusted-domains.example.net'
>>> q.expand('%{p2}.trusted-domains.example.net')
'example.org.trusted-domains.example.net'
>>> q.expand('%{p2}.trusted-domains.example.net.')
'example.org.trusted-domains.example.net'
......@@ -930,12 +1070,19 @@ class query(object):
if len(a) == 1 and self.strict < 2:
return a[0]
# check official SPF type first when it becomes more popular
try:
b = [t for t in self.dns_99(domain) if isSPF(t)]
except TempError,x:
# some braindead DNS servers hang on type 99 query
if self.strict > 1: raise x
b = []
if len(b) > 1:
raise PermError('Two or more type SPF spf records found.')
if len(b) == 1:
# FIXME: really must fully parse each record
# and compare with appropriate parts case insensitive.
if self.strict >= 2 and len(a) == 1 and a[0] != b[0]:
raise PermError(
if self.strict > 1 and len(a) == 1 and a[0] != b[0]:
#Changed from permerror to warning based on RFC 4408 Auth 48 change
raise AmbiguityWarning(
'v=spf1 records of both type TXT and SPF (type 99) present, but not identical')
return b[0]
if len(a) == 1:
......@@ -956,14 +1103,7 @@ class query(object):
def dns_99(self, domainname):
"Get a list of type SPF=99 records for a domain name."
if domainname:
try:
return [''.join(a) for a in self.dns(domainname, 'SPF')]
except TempError,x:
if self.strict: raise x
self.note_error(
'DNS responds, but times out on type99 (SPF) query: %s'%
domainname
)
return []
def dns_mx(self, domainname):
......@@ -972,18 +1112,29 @@ class query(object):
"""
# RFC 4408 section 5.4 "mx"
# To prevent DoS attacks, more than 10 MX names MUST NOT be looked up
mxnames = self.dns(domainname, 'MX')
if len(mxnames) > MAX_MX:
self.note_error('More than %d MX records returned'%MAX_MX)
if self.strict:
max = MAX_MX
if self.strict > 1 and len(mxnames) == 0:
raise AmbiguityWarning(
'No MX records found for mx mechanism', domainname)
else:
max = MAX_MX * 4
return [a for mx in self.dns(domainname, 'MX')[:max] \
for a in self.dns_a(mx[1])]
return [a for mx in mxnames[:max] for a in self.dns_a(mx[1])]
def dns_a(self, domainname):
"""Get a list of IP addresses for a domainname."""
if domainname:
if not domainname: return []
if self.strict > 1:
alist = self.dns(domainname, 'A')
if len(alist) == 0:
raise AmbiguityWarning('No A records found for',
domainname)
else:
return alist
return self.dns(domainname, 'A')
return []
def dns_aaaa(self, domainname):
"""Get a list of IPv6 addresses for a domainname."""
......@@ -996,6 +1147,20 @@ class query(object):
# To prevent DoS attacks, more than 10 PTR names MUST NOT be looked up
if self.strict:
max = MAX_PTR
if self.strict > 1:
#Break out the number of PTR records returned for testing
try:
ptrnames = self.dns_ptr(i)
ptrip = [p for p in ptrnames if i in self.dns_a(p)]
if len(ptrnames) > max:
warning = 'More than ' + str(max) + ' PTR records returned'
raise AmbiguityWarning(warning, i)
else:
if len(ptrnames) == 0:
raise AmbiguityWarning('No PTR records found for ptr mechanism', ptrnames)
return ptrip
except:
raise AmbiguityWarning('No PTR records found for ptr mechanism', ptrnames)
else:
max = MAX_PTR * 4
return [p for p in self.dns_ptr(i)[:max] if i in self.dns_a(p)]
......@@ -1030,6 +1195,7 @@ class query(object):
if not cnames:
cnames = {}
elif len(cnames) >= MAX_CNAME:
#return result # if too many == NX_DOMAIN
raise PermError(
'Length of CNAME chain exceeds %d' % MAX_CNAME)
cnames[name] = cname
......@@ -1041,22 +1207,21 @@ class query(object):
def get_header(self,res,receiver=None):
if not receiver:
receiver = self.r
if res in ('unknown','permerror'):
txt = ' '.join([res] + self.mech)
else:
txt = res
if res in ('pass','fail','softfail'):
return '%s (%s: %s) client-ip=%s; envelope-from=%s; helo=%s;' % (
txt,receiver,self.get_header_comment(res),self.i,
res,receiver,self.get_header_comment(res),self.i,
self.l + '@' + self.o, self.h)
if res == 'permerror':
return '%s (%s: %s)' % (' '.join([res] + self.mech),
receiver,self.get_header_comment(res))
return '%s (%s: %s)' % (res,receiver,self.get_header_comment(res))
def get_header_comment(self,res):
"""Return comment for Received-SPF header.
"""
sender = self.o
if res == 'pass':
if self.i.startswith('127.'):
return "localhost is always allowed."
else: return \
return \
"domain of %s designates %s as permitted sender" \
% (sender,self.i)
elif res == 'softfail': return \
......@@ -1069,10 +1234,10 @@ class query(object):
"%s is neither permitted nor denied by domain of %s" \
% (self.i,sender)
#"%s does not designate permitted sender hosts" % sender
elif res in ('unknown','permerror'): return \
elif res == 'permerror': return \
"permanent error in processing domain of %s: %s" \
% (sender, self.prob)
elif res in ('error','temperror'): return \
elif res == 'error': return \
"temporary error in processing during lookup of %s" % sender
elif res == 'fail': return \
"domain of %s does not designate %s as permitted sender" \
......@@ -1104,45 +1269,50 @@ def split_email(s, h):
def parse_mechanism(str, d):
"""Breaks A, MX, IP4, and PTR mechanisms into a (name, domain,
cidr) tuple. The domain portion defaults to d if not present,
cidr,cidr6) tuple. The domain portion defaults to d if not present,
the cidr defaults to 32 if not present.
Examples:
>>> parse_mechanism('a', 'foo.com')
('a', 'foo.com', 32)
('a', 'foo.com', None, None)
>>> parse_mechanism('a:bar.com', 'foo.com')
('a', 'bar.com', 32)
('a', 'bar.com', None, None)
>>> parse_mechanism('a/24', 'foo.com')
('a', 'foo.com', 24)
('a', 'foo.com', 24, None)
>>> parse_mechanism('A:foo:bar.com/16', 'foo.com')
('a', 'foo:bar.com', 16)
('a', 'foo:bar.com', 16, None)
>>> parse_mechanism('-exists:%{i}.%{s1}.100/86400.rate.%{d}','foo.com')
('-exists', '%{i}.%{s1}.100/86400.rate.%{d}', 32)
('-exists', '%{i}.%{s1}.100/86400.rate.%{d}', None, None)
>>> parse_mechanism('mx:%%%_/.Claranet.de/27','foo.com')
('mx', '%%%_/.Claranet.de', 27)
('mx', '%%%_/.Claranet.de', 27, None)
>>> parse_mechanism('mx:%{d}/27','foo.com')
('mx', '%{d}', 27)
('mx', '%{d}', 27, None)
>>> parse_mechanism('iP4:192.0.0.0/8','foo.com')
('ip4', '192.0.0.0', 8)
('ip4', '192.0.0.0', 8, None)
"""
a = RE_DUAL_CIDR.split(str)
if len(a) == 3:
str, cidr6 = a[0], int(a[1])
else:
cidr6 = None
a = RE_CIDR.split(str)
if len(a) == 3:
a, port = a[0], int(a[1])
str, cidr = a[0], int(a[1])
else:
a, port = str, 32
cidr = None
b = a.split(':',1)
if len(b) == 2:
return b[0].lower(), b[1], port
else:
return a.lower(), d, port
a = str.split(':',1)
if len(a) < 2:
return str.lower(), d, cidr, cidr6
return a[0].lower(), a[1], cidr, cidr6
def reverse_dots(name):
"""Reverse dotted IP addresses or domain names.
......@@ -1195,15 +1365,17 @@ def cidrmatch(i, ipaddrs, cidr_length = 32):
>>> cidrmatch('192.168.0.43', ['192.168.0.44', '192.168.0.45'], 24)
1
"""
try:
c = cidr(i, cidr_length)
for ip in ipaddrs:
if cidr(ip, cidr_length) == c:
return True
except socket.error: pass
return False
def cidr(i, n):
"""Convert an IP address string with a CIDR mask into a 32-bit
integer.
or 128-bit integer.
i must be a string of numbers 0..255 separated by dots '.'::
pre: forall([0 <= int(p) < 256 for p in i.split('.')])
......@@ -1249,7 +1421,12 @@ def addr2bin(str):
>>> 10 * (2 ** 24) + 93 * (2 ** 16) + 512
173867520
"""
try:
return struct.unpack("!L", socket.inet_aton(str))[0]
except socket.error:
if not socket.has_ipv6: raise
h,l = struct.unpack("!QQ", socket.inet_pton(socket.AF_INET6,str))
return h << 64 | l;
def bin2addr(addr):
"""Convert a numeric IPv4 address into string n.n.n.n form.
......@@ -1306,6 +1483,57 @@ def split(str, delimiters, joiner=None):
result.append(element)
return result
def insert_libspf_local_policy(spftxt,local=None):
"""Returns spftxt with local inserted just before last non-fail
mechanism. This is how the libspf{2} libraries handle "local-policy".
Examples:
>>> insert_libspf_local_policy('v=spf1 -all')
'v=spf1 -all'
>>> insert_libspf_local_policy('v=spf1 -all','mx')
'v=spf1 -all'
>>> insert_libspf_local_policy('v=spf1','a mx ptr')
'v=spf1 a mx ptr'
>>> insert_libspf_local_policy('v=spf1 mx -all','a ptr')
'v=spf1 mx a ptr -all'
>>> insert_libspf_local_policy('v=spf1 mx -include:foo.co +all','a ptr')
'v=spf1 mx a ptr -include:foo.co +all'
# FIXME: is this right? If so, "last non-fail" is a bogus description.
>>> insert_libspf_local_policy('v=spf1 mx ?include:foo.co +all','a ptr')
'v=spf1 mx a ptr ?include:foo.co +all'
>>> spf='v=spf1 ip4:1.2.3.4 -a:example.net -all'
>>> local='ip4:192.0.2.3 a:example.org'
>>> insert_libspf_local_policy(spf,local)
'v=spf1 ip4:1.2.3.4 ip4:192.0.2.3 a:example.org -a:example.net -all'
"""
# look to find the all (if any) and then put local
# just after last non-fail mechanism. This is how
# libspf2 handles "local policy", and some people
# apparently find it useful (don't ask me why).
if not local: return spftxt
spf = spftxt.split()[1:]
if spf:
# local policy is SPF mechanisms/modifiers with no
# 'v=spf1' at the start
spf.reverse() #find the last non-fail mechanism
for mech in spf:
# map '?' '+' or '-' to 'neutral' 'pass'
# or 'fail'
if not RESULTS.get(mech[0]):
# actually finds last mech with default result
where = spf.index(mech)
spf[where:where] = [local]
spf.reverse()
local = ' '.join(spf)
break
else:
return spftxt # No local policy adds for v=spf1 -all
# Processing limits not applied to local policy. Suggest
# inserting 'local' mechanism to handle this properly
#MAX_LOOKUP = 100
return 'v=spf1 '+local
def _test():
import doctest, spf
return doctest.testmod(spf)
......@@ -1329,6 +1557,7 @@ if __name__ == '__main__':
q = query(i=i, s=s, h=h, receiver=socket.gethostname(),
strict=False)
print q.check(sys.argv[1])
if q.perm_error: print q.perm_error.ext
if q.perm_error and q.perm_error.ext:
print q.perm_error.ext
else:
print USAGE
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please register or to comment