Mercurial > p > roundup > code
changeset 4480:1613754d2646
Fix first part of Password handling security issue2550688
(thanks Joseph Myers for reporting and Eli Collins for fixing)
Small change against original patch: We still accept plaintext passwords
(in known_schemes) when parsing encrypted password (e.g. from database).
This way existing databases with plaintext passwords continue to work (I
don't know of any, this would need patching on the users side) and all
regression tests pass.
| author | Ralf Schlatterbeck <schlatterbeck@users.sourceforge.net> |
|---|---|
| date | Thu, 14 Apr 2011 12:24:59 +0000 |
| parents | 0bdcb1e7f7ce |
| children | 9bbf3758c16a |
| files | CHANGES.txt doc/acknowledgements.txt roundup/backends/back_anydbm.py roundup/backends/rdbms_common.py roundup/hyperdb.py roundup/password.py roundup/roundupdb.py test/db_test_base.py test/test_security.py |
| diffstat | 9 files changed, 159 insertions(+), 42 deletions(-) [+] |
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--- a/CHANGES.txt Thu Apr 14 09:21:23 2011 +0000 +++ b/CHANGES.txt Thu Apr 14 12:24:59 2011 +0000 @@ -75,6 +75,8 @@ (Ralf Schlatterbeck) - Fixed bug in mailgw refactoring, patch issue2550697 (thanks Hubert Touvet) +- Fix first part of Password handling security issue2550688 (thanks + Joseph Myers for reporting and Eli Collins for fixing) 2010-10-08 1.4.16 (r4541)
--- a/doc/acknowledgements.txt Thu Apr 14 09:21:23 2011 +0000 +++ b/doc/acknowledgements.txt Thu Apr 14 12:24:59 2011 +0000 @@ -22,6 +22,7 @@ Steve Byan, Brett Cannon, Godefroid Chapelle, +Eli Collins, Roch'e Compaan, Wil Cooley, Joe Cooper, @@ -92,6 +93,7 @@ John Mitchell, Ramiro Morales, Toni Mueller, +Joseph Myers, Stefan Niederhauser, Truls E. Næss, Bryce L Nordgren,
--- a/roundup/backends/back_anydbm.py Thu Apr 14 09:21:23 2011 +0000 +++ b/roundup/backends/back_anydbm.py Thu Apr 14 12:24:59 2011 +0000 @@ -504,9 +504,7 @@ elif isinstance(prop, hyperdb.Interval) and v is not None: d[k] = date.Interval(v) elif isinstance(prop, hyperdb.Password) and v is not None: - p = password.Password() - p.unpack(v) - d[k] = p + d[k] = password.Password(encrypted=v) else: d[k] = v return d @@ -1744,7 +1742,7 @@ l.append((OTHER, k, [float(val) for val in v])) filterspec = l - + # now, find all the nodes that are active and pass filtering matches = [] cldb = self.db.getclassdb(cn) @@ -2028,9 +2026,7 @@ elif isinstance(prop, hyperdb.Interval): value = date.Interval(value) elif isinstance(prop, hyperdb.Password): - pwd = password.Password() - pwd.unpack(value) - value = pwd + value = password.Password(encrypted=value) d[propname] = value # get a new id if necessary
--- a/roundup/backends/rdbms_common.py Thu Apr 14 09:21:23 2011 +0000 +++ b/roundup/backends/rdbms_common.py Thu Apr 14 12:24:59 2011 +0000 @@ -2832,9 +2832,7 @@ elif isinstance(prop, hyperdb.Interval): value = date.Interval(value) elif isinstance(prop, hyperdb.Password): - pwd = password.Password() - pwd.unpack(value) - value = pwd + value = password.Password(encrypted=value) elif isinstance(prop, String): if isinstance(value, unicode): value = value.encode('utf8')
--- a/roundup/hyperdb.py Thu Apr 14 09:21:23 2011 +0000 +++ b/roundup/hyperdb.py Thu Apr 14 12:24:59 2011 +0000 @@ -72,24 +72,12 @@ def from_raw(self, value, **kw): if not value: return None - m = password.Password.pwre.match(value) - if m: - # password is being given to us encrypted - p = password.Password() - p.scheme = m.group(1) - if p.scheme not in 'SHA crypt plaintext'.split(): - raise HyperdbValueError, \ - ('property %s: unknown encryption scheme %r') %\ - (kw['propname'], p.scheme) - p.password = m.group(2) - value = p - else: - try: - value = password.Password(value) - except password.PasswordValueError, message: - raise HyperdbValueError, \ - _('property %s: %s')%(kw['propname'], message) - return value + try: + return password.Password(encrypted=value, strict=True) + except password.PasswordValueError, message: + raise HyperdbValueError, \ + _('property %s: %s')%(kw['propname'], message) + def sort_repr (self, cls, val, name): if not val: return val @@ -1307,9 +1295,7 @@ elif isinstance(prop, Interval): value = date.Interval(value) elif isinstance(prop, Password): - pwd = password.Password() - pwd.unpack(value) - value = pwd + value = password.Password(encrypted=value) params[propname] = value elif action == 'create' and params: # old tracker with data stored in the create! @@ -1337,7 +1323,7 @@ def has_role(self, nodeid, *roles): '''See if this node has any roles that appear in roles. - + For convenience reasons we take a list. In standard schemas only a user has a roles property but this may be different in customized schemas.
--- a/roundup/password.py Thu Apr 14 09:21:23 2011 +0000 +++ b/roundup/password.py Thu Apr 14 12:24:59 2011 +0000 @@ -22,12 +22,96 @@ __docformat__ = 'restructuredtext' import re, string, random +from base64 import b64encode, b64decode from roundup.anypy.hashlib_ import md5, sha1 try: import crypt except ImportError: crypt = None +_bempty = "" +_bjoin = _bempty.join + +def getrandbytes(count): + return _bjoin(chr(random.randint(0,255)) for i in xrange(count)) + +#NOTE: PBKDF2 hash is using this variant of base64 to minimize encoding size, +# and have charset that's compatible w/ unix crypt variants +def h64encode(data): + """encode using variant of base64""" + return b64encode(data, "./").strip("=\n") + +def h64decode(data): + """decode using variant of base64""" + off = len(data) % 4 + if off == 0: + return b64decode(data, "./") + elif off == 1: + raise ValueError("invalid bas64 input") + elif off == 2: + return b64decode(data + "==", "./") + else: + return b64decode(data + "=", "./") + +try: + from M2Crypto.EVP import pbkdf2 as _pbkdf2 +except ImportError: + #no m2crypto - make our own pbkdf2 function + from struct import pack + from hmac import HMAC + try: + from hashlib import sha1 + except ImportError: + from sha import new as sha1 + + def xor_bytes(left, right): + "perform bitwise-xor of two byte-strings" + return _bjoin(chr(ord(l) ^ ord(r)) for l, r in zip(left, right)) + + def _pbkdf2(password, salt, rounds, keylen): + digest_size = 20 # sha1 generates 20-byte blocks + total_blocks = int((keylen+digest_size-1)/digest_size) + hmac_template = HMAC(password, None, sha1) + out = _bempty + for i in xrange(1, total_blocks+1): + hmac = hmac_template.copy() + hmac.update(salt + pack(">L",i)) + block = tmp = hmac.digest() + for j in xrange(rounds-1): + hmac = hmac_template.copy() + hmac.update(tmp) + tmp = hmac.digest() + #TODO: need to speed up this call + block = xor_bytes(block, tmp) + out += block + return out[:keylen] + +def pbkdf2(password, salt, rounds, keylen): + """pkcs#5 password-based key derivation v2.0 + + :arg password: passphrase to use to generate key (if unicode, converted to utf-8) + :arg salt: salt string to use when generating key (if unicode, converted to utf-8) + :param rounds: number of rounds to use to generate key + :arg keylen: number of bytes to generate + + If M2Crypto is present, uses it's implementation as backend. + + :returns: + raw bytes of generated key + """ + if isinstance(password, unicode): + password = password.encode("utf-8") + if isinstance(salt, unicode): + salt = salt.encode("utf-8") + if keylen > 40: + #NOTE: pbkdf2 allows up to (2**31-1)*20 bytes, + # but m2crypto has issues on some platforms above 40, + # and such sizes aren't needed for a password hash anyways... + raise ValueError, "key length too large" + if rounds < 1: + raise ValueError, "rounds must be positive number" + return _pbkdf2(password, salt, rounds, keylen) + class PasswordValueError(ValueError): """ The password value is not valid """ pass @@ -37,7 +121,33 @@ """ if plaintext is None: plaintext = "" - if scheme == 'SHA': + if scheme == "PBKDF2": + if other: + #assume it has format "{rounds}${salt}${digest}" + if isinstance(other, unicode): + other = other.encode("ascii") + try: + rounds, salt, digest = other.split("$") + except ValueError: + raise PasswordValueError, "invalid PBKDF2 hash (wrong number of separators)" + if rounds.startswith("0"): + raise PasswordValueError, "invalid PBKDF2 hash (zero-padded rounds)" + try: + rounds = int(rounds) + except ValueError: + raise PasswordValueError, "invalid PBKDF2 hash (invalid rounds)" + raw_salt = h64decode(salt) + else: + raw_salt = getrandbytes(20) + salt = h64encode(raw_salt) + #FIXME: find way to access config, so default rounds + # can be altered for faster/slower hosts via config.ini + rounds = 10000 + if rounds < 1000: + raise PasswordValueError, "invalid PBKDF2 hash (rounds too low)" + raw_digest = pbkdf2(plaintext, raw_salt, rounds, 20) + return "%d$%s$%s" % (rounds, salt, h64encode(raw_digest)) + elif scheme == 'SHA': s = sha1(plaintext).hexdigest() elif scheme == 'MD5': s = md5(plaintext).hexdigest() @@ -80,24 +190,26 @@ >>> 'not sekrit' != p 1 """ + #TODO: code to migrate from old password schemes. - default_scheme = 'SHA' # new encryptions use this scheme + default_scheme = 'PBKDF2' # new encryptions use this scheme + known_schemes = [ "PBKDF2", "SHA", "MD5", "crypt", "plaintext" ] pwre = re.compile(r'{(\w+)}(.+)') - def __init__(self, plaintext=None, scheme=None, encrypted=None): + def __init__(self, plaintext=None, scheme=None, encrypted=None, strict=False): """Call setPassword if plaintext is not None.""" if scheme is None: scheme = self.default_scheme if plaintext is not None: self.setPassword (plaintext, scheme) elif encrypted is not None: - self.unpack(encrypted, scheme) + self.unpack(encrypted, scheme, strict=strict) else: self.scheme = self.default_scheme self.password = None self.plaintext = None - def unpack(self, encrypted, scheme=None): + def unpack(self, encrypted, scheme=None, strict=False): """Set the password info from the scheme:<encryted info> string (the inverse of __str__) """ @@ -109,6 +221,8 @@ else: # currently plaintext - encrypt self.setPassword(encrypted, scheme) + if strict and self.scheme not in self.known_schemes: + raise PasswordValueError, "unknown encryption scheme: %r" % (self.scheme,) def setPassword(self, plaintext, scheme=None): """Sets encrypts plaintext.""" @@ -160,6 +274,22 @@ assert 'sekrit' == p assert 'not sekrit' != p + # PBKDF2 - low level function + from binascii import unhexlify + k = pbkdf2("password", "ATHENA.MIT.EDUraeburn", 1200, 32) + assert k == unhexlify("5c08eb61fdf71e4e4ec3cf6ba1f5512ba7e52ddbc5e5142f708a31e2e62b1e13") + + # PBKDF2 - hash function + h = "5000$7BvbBq.EZzz/O0HuwX3iP.nAG3s$g3oPnFFaga2BJaX5PoPRljl4XIE" + assert encodePassword("sekrit", "PBKDF2", h) == h + + # PBKDF2 - high level integration + p = Password('sekrit', 'PBKDF2') + assert p == 'sekrit' + assert p != 'not sekrit' + assert 'sekrit' == p + assert 'not sekrit' != p + if __name__ == '__main__': test()
--- a/roundup/roundupdb.py Thu Apr 14 09:21:23 2011 +0000 +++ b/roundup/roundupdb.py Thu Apr 14 12:24:59 2011 +0000 @@ -103,8 +103,7 @@ elif isinstance(proptype, hyperdb.Interval): props[propname] = date.Interval(value) elif isinstance(proptype, hyperdb.Password): - props[propname] = password.Password() - props[propname].unpack(value) + props[propname] = password.Password(encrypted=value) # tag new user creation with 'admin' self.journaltag = 'admin' @@ -241,7 +240,7 @@ user or a user who has already seen the message. Also check permissions on the message if not a system message: A user must have view permission on content and - files to be on the receiver list. We do *not* check the + files to be on the receiver list. We do *not* check the author etc. for now. """ allowed = True
--- a/test/db_test_base.py Thu Apr 14 09:21:23 2011 +0000 +++ b/test/db_test_base.py Thu Apr 14 12:24:59 2011 +0000 @@ -35,7 +35,7 @@ config.RDBMS_HOST = "localhost" config.RDBMS_USER = "rounduptest" config.RDBMS_PASSWORD = "rounduptest" -#config.RDBMS_TEMPLATE = "template0" +config.RDBMS_TEMPLATE = "template0" #config.logging = MockNull() # these TRACKER_WEB and MAIL_DOMAIN values are used in mailgw tests config.MAIL_DOMAIN = "your.tracker.email.domain.example"
--- a/test/test_security.py Thu Apr 14 09:21:23 2011 +0000 +++ b/test/test_security.py Thu Apr 14 12:24:59 2011 +0000 @@ -23,7 +23,7 @@ import os, unittest, shutil from roundup import backends -from roundup.password import Password +import roundup.password from db_test_base import setupSchema, MyTestCase, config class PermissionTest(MyTestCase): @@ -233,6 +233,10 @@ self.assertEquals(has(uimu, 'issue', 'messages.recipients'), 1) self.assertEquals(has(uimu, 'issue', 'messages.recipients.username'), 1) + # roundup.password has its own built-in test, call it. + def test_password(self): + roundup.password.test() + def test_suite(): suite = unittest.TestSuite() suite.addTest(unittest.makeSuite(PermissionTest))