DandelionNStuff/dkimpy-smtputf8
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Extract signature field validation.

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This commit is contained in:
William Grant
2011-03-09 21:40:51 +11:00
parent ece86c0e67
commit a6374ed26d
1 changed files with 49 additions and 43 deletions
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dkim/__init__.py
+49 -43
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@@ -143,6 +143,54 @@ def parse_public_key(data):
return pk
def validate_signature_fields(sig, debuglog=None):
mandatory_fields = ('v', 'a', 'b', 'bh', 'd', 'h', 's')
for field in mandatory_fields:
if field not in sig:
if debuglog is not None:
print >>debuglog, "signature missing %s=" % field
return False
if sig['v'] != "1":
if debuglog is not None:
print >>debuglog, "v= value is not 1 (%s)" % sig['v']
return False
if re.match(r"[\s0-9A-Za-z+/]+=*$", sig['b']) is None:
if debuglog is not None:
print >>debuglog, "b= value is not valid base64 (%s)" % sig['b']
return False
if re.match(r"[\s0-9A-Za-z+/]+=*$", sig['bh']) is None:
if debuglog is not None:
print >>debuglog, "bh= value is not valid base64 (%s)" % sig['bh']
return False
if 'i' in sig and (not sig['i'].endswith(sig['d']) or sig['i'][-len(sig['d'])-1] not in "@."):
if debuglog is not None:
print >>debuglog, "i= domain is not a subdomain of d= (i=%s d=%d)" % (sig['i'], sig['d'])
return False
if 'l' in sig and re.match(r"\d{,76}$", sig['l']) is None:
if debuglog is not None:
print >>debuglog, "l= value is not a decimal integer (%s)" % sig['l']
return False
if 'q' in sig and sig['q'] != "dns/txt":
if debuglog is not None:
print >>debuglog, "q= value is not dns/txt (%s)" % sig['q']
return False
if 't' in sig and re.match(r"\d+$", sig['t']) is None:
if debuglog is not None:
print >>debuglog, "t= value is not a decimal integer (%s)" % sig['t']
return False
if 'x' in sig:
if re.match(r"\d+$", sig['x']) is None:
if debuglog is not None:
print >>debuglog, "x= value is not a decimal integer (%s)" % sig['x']
return False
if int(sig['x']) < int(sig['t']):
if debuglog is not None:
print >>debuglog, "x= value is less than t= value (x=%s t=%s)" % (sig['x'], sig['t'])
return False
return True
INTEGER = 0x02
BIT_STRING = 0x03
OCTET_STRING = 0x04
@@ -466,50 +514,8 @@ def verify(message, debuglog=None, dnsfunc=dnstxt):
if debuglog is not None:
print >>debuglog, "sig:", sig
mandatory_fields = ('v', 'a', 'b', 'bh', 'd', 'h', 's')
for field in mandatory_fields:
if field not in sig:
if debuglog is not None:
print >>debuglog, "signature missing %s=" % field
return False
if sig['v'] != "1":
if debuglog is not None:
print >>debuglog, "v= value is not 1 (%s)" % sig['v']
if not validate_signature_fields(sig, debuglog):
return False
if re.match(r"[\s0-9A-Za-z+/]+=*$", sig['b']) is None:
if debuglog is not None:
print >>debuglog, "b= value is not valid base64 (%s)" % sig['b']
return False
if re.match(r"[\s0-9A-Za-z+/]+=*$", sig['bh']) is None:
if debuglog is not None:
print >>debuglog, "bh= value is not valid base64 (%s)" % sig['bh']
return False
if 'i' in sig and (not sig['i'].endswith(sig['d']) or sig['i'][-len(sig['d'])-1] not in "@."):
if debuglog is not None:
print >>debuglog, "i= domain is not a subdomain of d= (i=%s d=%d)" % (sig['i'], sig['d'])
return False
if 'l' in sig and re.match(r"\d{,76}$", sig['l']) is None:
if debuglog is not None:
print >>debuglog, "l= value is not a decimal integer (%s)" % sig['l']
return False
if 'q' in sig and sig['q'] != "dns/txt":
if debuglog is not None:
print >>debuglog, "q= value is not dns/txt (%s)" % sig['q']
return False
if 't' in sig and re.match(r"\d+$", sig['t']) is None:
if debuglog is not None:
print >>debuglog, "t= value is not a decimal integer (%s)" % sig['t']
return False
if 'x' in sig:
if re.match(r"\d+$", sig['x']) is None:
if debuglog is not None:
print >>debuglog, "x= value is not a decimal integer (%s)" % sig['x']
return False
if int(sig['x']) < int(sig['t']):
if debuglog is not None:
print >>debuglog, "x= value is less than t= value (x=%s t=%s)" % (sig['x'], sig['t'])
return False
m = re.match("(\w+)(?:/(\w+))?$", sig['c'])
if m is None: