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import OpenSSL.crypto
import sexp.access
import sexp.encode
import time
import re
class UnknownMethod(Exception):
pass
class PublicKey:
def format(self):
raise NotImplemented()
def sign(self, data):
# returns a list of method,signature tuples.
raise NotImplemented()
def checkSignature(self, method, data, signature):
# returns True, False, or raises UnknownMethod.
raise NotImplemented()
def getKeyID(self):
raise NotImplemented()
def getRoles(self):
raise NotImplemented()
class KeyDB:
def __init__(self):
self.keys = {}
def addKey(self, k):
self.keys[k.getKeyID()] = k
def getKey(self, keyid):
return self.keys[keyid]
def rolePathMatches(rolePath, path):
"""
>>> rolePath.matches("a/b/c/", "a/b/c/")
True
>>> rolePath.matches("**/c.*", "a/b/c.txt")
True
"""
rolePath = re.escape(rolePath).replace(r'\*\*', r'.*')
rolePath = rolePath.replace(r'\*', r'[^/]*')
rolePath += "$"
return re.match(rolePath, path) != None
def checkSignatures(signed, keyDB, role, path):
goodSigs = []
badSigs = []
unknownSigs = []
tangentialSigs = []
for signature in sexp.access.s_children(signed, "signature"):
attrs = signature[1]
sig = attrs[2]
keyid = s_child(attrs, "keyid")[1]
try:
key = keyDB.getKey(keyid)
except KeyError:
unknownSigs.append(keyid)
continue
method = s_child(attrs, "method")[1]
try:
result = key.checkSignature(method, data, sig)
except UnknownMethod:
continue
if result == True:
if role is not None:
for r,p in key.getRoles():
if r == role and rolePathMatches(p, path):
break
else:
tangentialSigs.append(sig)
continue
goodSigs.append(keyid)
else:
badSigs.append(keyid)
def sign(signed, key):
assert sexp.access.s_tag(signed) == 'signed'
s = signed[1]
keyid = key.keyID()
oldsignatures = [ s for s in signed[2:] if s_child(s[1], "keyid") != keyid ]
signed[2:] = oldsignatures
for method, sig in key.sign(s):
signed.append(['signature', [['keyid', keyid], ['method', method]]
sig])
def formatTime(t):
return time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(t))
def parseTime(s):
return time.timegm(time.strptime(s, "%Y-%m-%d %H:%M:%S"))
TIME_SCHEMA = r"""/\{d}4-\d{2}-\d{2} \d{2}:\d{2}:\d{2}/"""
ATTRS_SCHEMA = r"""(:anyof (_ *))"""
SIGNED_SCHEMA = r"""
(=signed
_
(:someof
(=signature ((:unordered
(=keyid _) (=method _) .ATTRS)) _)
)
)"""
KEYFILE_SCHEMA = r"""
(=keylist
(=ts .TIME)
(=keys
(:anyof
(=key ((:unordered (=roles (:someof (. .))) .ATTRS)) _)
))
*
)"""
MIRRORLIST_SCHEMA = r"""
(=mirrorlist
(=ts .TIME)
(=mirrors (:anyof
(=mirror ((:unordered (=name .) (=urlbase .) (=contents (:someof .))
.ATTRS)))))
*)
"""
TIMESTAMP_SCHEMA = r"""
(=ts
((:unordered (=at .TIME) (=m .TIME .) (=k .TIME .)
(:anyof (=b . . .TIME . .)) .ATTRS))
)"""
BUNDLE_SCHEMA = r"""
(=bundle
(=at .TIME)
(=os .)
(:maybe (=arch .))
(=packages
(:someof
(. . . . ((:unordered
(:maybe (=order . . .))
(:maybe (=optional))
(:anyof (=gloss . .))
(:anyof (=longgloss . .))
.ATTRS)))
)
)
*
)"""
PACKAGE_SCHEMA = r"""
(=package
((:unordred (=name .)
(=version .)
(=format . (.ATTRS))
(=path .)
(=ts .TIME)
(=digest .)
(:anyof (=shortdesc . .))
(:anyof (=longdesc . .))
.ATTRS)))
"""
|
