"""passlib.handlers.des_crypt - traditional unix (DES) crypt and variants"""
#=============================================================================
# imports
#=============================================================================
# core
import re
import logging; log = logging.getLogger(__name__)
from warnings import warn
# site
# pkg
from passlib.utils import safe_crypt, test_crypt, to_unicode
from passlib.utils.binary import h64, h64big
from passlib.utils.compat import byte_elem_value, u, uascii_to_str, unicode, suppress_cause
from passlib.crypto.des import des_encrypt_int_block
import passlib.utils.handlers as uh
# local
__all__ = [
"des_crypt",
"bsdi_crypt",
"bigcrypt",
"crypt16",
]
#=============================================================================
# pure-python backend for des_crypt family
#=============================================================================
_BNULL = b'\x00'
def _crypt_secret_to_key(secret):
"""convert secret to 64-bit DES key.
this only uses the first 8 bytes of the secret,
and discards the high 8th bit of each byte at that.
a null parity bit is inserted after every 7th bit of the output.
"""
# NOTE: this would set the parity bits correctly,
# but des_encrypt_int_block() would just ignore them...
##return sum(expand_7bit(byte_elem_value(c) & 0x7f) << (56-i*8)
## for i, c in enumerate(secret[:8]))
return sum((byte_elem_value(c) & 0x7f) << (57-i*8)
for i, c in enumerate(secret[:8]))
def _raw_des_crypt(secret, salt):
"""pure-python backed for des_crypt"""
assert len(salt) == 2
# NOTE: some OSes will accept non-HASH64 characters in the salt,
# but what value they assign these characters varies wildy,
# so just rejecting them outright.
# the same goes for single-character salts...
# some OSes duplicate the char, some insert a '.' char,
# and openbsd does (something) which creates an invalid hash.
salt_value = h64.decode_int12(salt)
# gotta do something - no official policy since this predates unicode
if isinstance(secret, unicode):
secret = secret.encode("utf-8")
assert isinstance(secret, bytes)
# forbidding NULL char because underlying crypt() rejects them too.
if _BNULL in secret:
raise uh.exc.NullPasswordError(des_crypt)
# convert first 8 bytes of secret string into an integer
key_value = _crypt_secret_to_key(secret)
# run data through des using input of 0
result = des_encrypt_int_block(key_value, 0, salt_value, 25)
# run h64 encode on result
return h64big.encode_int64(result)
def _bsdi_secret_to_key(secret):
"""convert secret to DES key used by bsdi_crypt"""
key_value = _crypt_secret_to_key(secret)
idx = 8
end = len(secret)
while idx < end:
next = idx + 8
tmp_value = _crypt_secret_to_key(secret[idx:next])
key_value = des_encrypt_int_block(key_value, key_value) ^ tmp_value
idx = next
return key_value
def _raw_bsdi_crypt(secret, rounds, salt):
"""pure-python backend for bsdi_crypt"""
# decode salt
salt_value = h64.decode_int24(salt)
# gotta do something - no official policy since this predates unicode
if isinstance(secret, unicode):
secret = secret.encode("utf-8")
assert isinstance(secret, bytes)
# forbidding NULL char because underlying crypt() rejects them too.
if _BNULL in secret:
raise uh.exc.NullPasswordError(bsdi_crypt)
# convert secret string into an integer
key_value = _bsdi_secret_to_key(secret)
# run data through des using input of 0
result = des_encrypt_int_block(key_value, 0, salt_value, rounds)
# run h64 encode on result
return h64big.encode_int64(result)
#=============================================================================
# handlers
#=============================================================================
class des_crypt(uh.TruncateMixin, uh.HasManyBackends, uh.HasSalt, uh.GenericHandler):
"""This class implements the des-crypt password hash, and follows the :ref:`password-hash-api`.
It supports a fixed-length salt.
The :meth:`~passlib.ifc.PasswordHash.using` method accepts the following optional keywords:
:type salt: str
:param salt:
Optional salt string.
If not specified, one will be autogenerated (this is recommended).
If specified, it must be 2 characters, drawn from the regexp range ``[./0-9A-Za-z]``.
:param bool truncate_error:
By default, des_crypt will silently truncate passwords larger than 8 bytes.
Setting ``truncate_error=True`` will cause :meth:`~passlib.ifc.PasswordHash.hash`
to raise a :exc:`~passlib.exc.PasswordTruncateError` instead.
.. versionadded:: 1.7
:type relaxed: bool
:param relaxed:
By default, providing an invalid value for one of the other
keywords will result in a :exc:`ValueError`. If ``relaxed=True``,
and the error can be corrected, a :exc:`~passlib.exc.PasslibHashWarning`
will be issued instead. Correctable errors include
``salt`` strings that are too long.
.. versionadded:: 1.6
"""
#===================================================================
# class attrs
#===================================================================
#--------------------
# PasswordHash
#--------------------
name = "des_crypt"
setting_kwds = ("salt", "truncate_error")
#--------------------
# GenericHandler
#--------------------
checksum_chars = uh.HASH64_CHARS
checksum_size = 11
#--------------------
# HasSalt
#--------------------
min_salt_size = max_salt_size = 2
salt_chars = uh.HASH64_CHARS
#--------------------
# TruncateMixin
#--------------------
truncate_size = 8
#===================================================================
# formatting
#===================================================================
# FORMAT: 2 chars of H64-encoded salt + 11 chars of H64-encoded checksum
_hash_regex = re.compile(u(r"""
^
(?P<salt>[./a-z0-9]{2})
(?P<chk>[./a-z0-9]{11})?
$"""), re.X|re.I)
@classmethod
def from_string(cls, hash):
hash = to_unicode(hash, "ascii", "hash")
salt, chk = hash[:2], hash[2:]
return cls(salt=salt, checksum=chk or None)
def to_string(self):
hash = u("%s%s") % (self.salt, self.checksum)
return uascii_to_str(hash)
#===================================================================
# digest calculation
#===================================================================
def _calc_checksum(self, secret):
# check for truncation (during .hash() calls only)
if self.use_defaults:
self._check_truncate_policy(secret)
return self._calc_checksum_backend(secret)
#===================================================================
# backend
#===================================================================
backends = ("os_crypt", "builtin")
#---------------------------------------------------------------
# os_crypt backend
#---------------------------------------------------------------
@classmethod
def _load_backend_os_crypt(cls):
if test_crypt("test", 'abgOeLfPimXQo'):
cls._set_calc_checksum_backend(cls._calc_checksum_os_crypt)
return True
else:
return False
def _calc_checksum_os_crypt(self, secret):
# NOTE: we let safe_crypt() encode unicode secret -> utf8;
# no official policy since des-crypt predates unicode
hash = safe_crypt(secret, self.salt)
if hash is None:
# py3's crypt.crypt() can't handle non-utf8 bytes.
# fallback to builtin alg, which is always available.
return self._calc_checksum_builtin(secret)
if not hash.startswith(self.salt) or len(hash) != 13:
raise uh.exc.CryptBackendError(self, self.salt, hash)
return hash[2:]
#---------------------------------------------------------------
# builtin backend
#---------------------------------------------------------------
@classmethod
def _load_backend_builtin(cls):
cls._set_calc_checksum_backend(cls._calc_checksum_builtin)
return True
def _calc_checksum_builtin(self, secret):
return _raw_des_crypt(secret, self.salt.encode("ascii")).decode("ascii")
#===================================================================
# eoc
#===================================================================
class bsdi_crypt(uh.HasManyBackends, uh.HasRounds, uh.HasSalt, uh.GenericHandler):
"""This class implements the BSDi-Crypt password hash, and follows the :ref:`password-hash-api`.
It supports a fixed-length salt, and a variable number of rounds.
The :meth:`~passlib.ifc.PasswordHash.using` method accepts the following optional keywords:
:type salt: str
:param salt:
Optional salt string.
If not specified, one will be autogenerated (this is recommended).
If specified, it must be 4 characters, drawn from the regexp range ``[./0-9A-Za-z]``.
:type rounds: int
:param rounds:
Optional number of rounds to use.
Defaults to 5001, must be between 1 and 16777215, inclusive.
:type relaxed: bool
:param relaxed:
By default, providing an invalid value for one of the other
keywords will result in a :exc:`ValueError`. If ``relaxed=True``,
and the error can be corrected, a :exc:`~passlib.exc.PasslibHashWarning`
will be issued instead. Correctable errors include ``rounds``
that are too small or too large, and ``salt`` strings that are too long.
.. versionadded:: 1.6
.. versionchanged:: 1.6
:meth:`hash` will now issue a warning if an even number of rounds is used
(see :ref:`bsdi-crypt-security-issues` regarding weak DES keys).
"""
#===================================================================
# class attrs
#===================================================================
#--GenericHandler--
name = "bsdi_crypt"
setting_kwds = ("salt", "rounds")
checksum_size = 11
checksum_chars = uh.HASH64_CHARS
#--HasSalt--
min_salt_size = max_salt_size = 4
salt_chars = uh.HASH64_CHARS
#--HasRounds--
default_rounds = 5001
min_rounds = 1
max_rounds = 16777215 # (1<<24)-1
rounds_cost = "linear"
# NOTE: OpenBSD login.conf reports 7250 as minimum allowed rounds,
# but that seems to be an OS policy, not a algorithm limitation.
#===================================================================
# parsing
#===================================================================
_hash_regex = re.compile(u(r"""
^
_
(?P<rounds>[./a-z0-9]{4})
(?P<salt>[./a-z0-9]{4})
(?P<chk>[./a-z0-9]{11})?
$"""), re.X|re.I)
@classmethod
def from_string(cls, hash):
hash = to_unicode(hash, "ascii", "hash")
m = cls._hash_regex.match(hash)
if not m:
raise uh.exc.InvalidHashError(cls)
rounds, salt, chk = m.group("rounds", "salt", "chk")
return cls(
rounds=h64.decode_int24(rounds.encode("ascii")),
salt=salt,
checksum=chk,
)
def to_string(self):
hash = u("_%s%s%s") % (h64.encode_int24(self.rounds).decode("ascii"),
self.salt, self.checksum)
return uascii_to_str(hash)
#===================================================================
# validation
#===================================================================
# NOTE: keeping this flag for admin/choose_rounds.py script.
# want to eventually expose rounds logic to that script in better way.
_avoid_even_rounds = True
@classmethod
def using(cls, **kwds):
subcls = super(bsdi_crypt, cls).using(**kwds)
if not subcls.default_rounds & 1:
# issue warning if caller set an even 'rounds' value.
warn("bsdi_crypt rounds should be odd, as even rounds may reveal weak DES keys",
uh.exc.PasslibSecurityWarning)
return subcls
@classmethod
def _generate_rounds(cls):
rounds = super(bsdi_crypt, cls)._generate_rounds()
# ensure autogenerated rounds are always odd
# NOTE: doing this even for default_rounds so needs_update() doesn't get
# caught in a loop.
# FIXME: this technically might generate a rounds value 1 larger
# than the requested upper bound - but better to err on side of safety.
return rounds|1
#===================================================================
# migration
#===================================================================
def _calc_needs_update(self, **kwds):
# mark bsdi_crypt hashes as deprecated if they have even rounds.
if not self.rounds & 1:
return True
# hand off to base implementation
return super(bsdi_crypt, self)._calc_needs_update(**kwds)
#===================================================================
# backends
#===================================================================
backends = ("os_crypt", "builtin")
#---------------------------------------------------------------
# os_crypt backend
#---------------------------------------------------------------
@classmethod
def _load_backend_os_crypt(cls):
if test_crypt("test", '_/...lLDAxARksGCHin.'):
cls._set_calc_checksum_backend(cls._calc_checksum_os_crypt)
return True
else:
return False
def _calc_checksum_os_crypt(self, secret):
config = self.to_string()
hash = safe_crypt(secret, config)
if hash is None:
# py3's crypt.crypt() can't handle non-utf8 bytes.
# fallback to builtin alg, which is always available.
return self._calc_checksum_builtin(secret)
if not hash.startswith(config[:9]) or len(hash) != 20:
raise uh.exc.CryptBackendError(self, config, hash)
return hash[-11:]
#---------------------------------------------------------------
# builtin backend
#---------------------------------------------------------------
@classmethod
def _load_backend_builtin(cls):
cls._set_calc_checksum_backend(cls._calc_checksum_builtin)
return True
def _calc_checksum_builtin(self, secret):
return _raw_bsdi_crypt(secret, self.rounds, self.salt.encode("ascii")).decode("ascii")
#===================================================================
# eoc
#===================================================================
class bigcrypt(uh.HasSalt, uh.GenericHandler):
"""This class implements the BigCrypt password hash, and follows the :ref:`password-hash-api`.
It supports a fixed-length salt.
The :meth:`~passlib.ifc.PasswordHash.using` method accepts the following optional keywords:
:type salt: str
:param salt:
Optional salt string.
If not specified, one will be autogenerated (this is recommended).
If specified, it must be 22 characters, drawn from the regexp range ``[./0-9A-Za-z]``.
:type relaxed: bool
:param relaxed:
By default, providing an invalid value for one of the other
keywords will result in a :exc:`ValueError`. If ``relaxed=True``,
and the error can be corrected, a :exc:`~passlib.exc.PasslibHashWarning`
will be issued instead. Correctable errors include
``salt`` strings that are too long.
.. versionadded:: 1.6
"""
#===================================================================
# class attrs
#===================================================================
#--GenericHandler--
name = "bigcrypt"
setting_kwds = ("salt",)
checksum_chars = uh.HASH64_CHARS
# NOTE: checksum chars must be multiple of 11
#--HasSalt--
min_salt_size = max_salt_size = 2
salt_chars = uh.HASH64_CHARS
#===================================================================
# internal helpers
#===================================================================
_hash_regex = re.compile(u(r"""
^
(?P<salt>[./a-z0-9]{2})
(?P<chk>([./a-z0-9]{11})+)?
$"""), re.X|re.I)
@classmethod
def from_string(cls, hash):
hash = to_unicode(hash, "ascii", "hash")
m = cls._hash_regex.match(hash)
if not m:
raise uh.exc.InvalidHashError(cls)
salt, chk = m.group("salt", "chk")
return cls(salt=salt, checksum=chk)
def to_string(self):
hash = u("%s%s") % (self.salt, self.checksum)
return uascii_to_str(hash)
def _norm_checksum(self, checksum, relaxed=False):
checksum = super(bigcrypt, self)._norm_checksum(checksum, relaxed=relaxed)
if len(checksum) % 11:
raise uh.exc.InvalidHashError(self)
return checksum
#===================================================================
# backend
#===================================================================
def _calc_checksum(self, secret):
if isinstance(secret, unicode):
secret = secret.encode("utf-8")
chk = _raw_des_crypt(secret, self.salt.encode("ascii"))
idx = 8
end = len(secret)
while idx < end:
next = idx + 8
chk += _raw_des_crypt(secret[idx:next], chk[-11:-9])
idx = next
return chk.decode("ascii")
#===================================================================
# eoc
#===================================================================
class crypt16(uh.TruncateMixin, uh.HasSalt, uh.GenericHandler):
"""This class implements the crypt16 password hash, and follows the :ref:`password-hash-api`.
It supports a fixed-length salt.
The :meth:`~passlib.ifc.PasswordHash.using` method accepts the following optional keywords:
:type salt: str
:param salt:
Optional salt string.
If not specified, one will be autogenerated (this is recommended).
If specified, it must be 2 characters, drawn from the regexp range ``[./0-9A-Za-z]``.
:param bool truncate_error:
By default, crypt16 will silently truncate passwords larger than 16 bytes.
Setting ``truncate_error=True`` will cause :meth:`~passlib.ifc.PasswordHash.hash`
to raise a :exc:`~passlib.exc.PasswordTruncateError` instead.
.. versionadded:: 1.7
:type relaxed: bool
:param relaxed:
By default, providing an invalid value for one of the other
keywords will result in a :exc:`ValueError`. If ``relaxed=True``,
and the error can be corrected, a :exc:`~passlib.exc.PasslibHashWarning`
will be issued instead. Correctable errors include
``salt`` strings that are too long.
.. versionadded:: 1.6
"""
#===================================================================
# class attrs
#===================================================================
#--------------------
# PasswordHash
#--------------------
name = "crypt16"
setting_kwds = ("salt", "truncate_error")
#--------------------
# GenericHandler
#--------------------
checksum_size = 22
checksum_chars = uh.HASH64_CHARS
#--------------------
# HasSalt
#--------------------
min_salt_size = max_salt_size = 2
salt_chars = uh.HASH64_CHARS
#--------------------
# TruncateMixin
#--------------------
truncate_size = 16
#===================================================================
# internal helpers
#===================================================================
_hash_regex = re.compile(u(r"""
^
(?P<salt>[./a-z0-9]{2})
(?P<chk>[./a-z0-9]{22})?
$"""), re.X|re.I)
@classmethod
def from_string(cls, hash):
hash = to_unicode(hash, "ascii", "hash")
m = cls._hash_regex.match(hash)
if not m:
raise uh.exc.InvalidHashError(cls)
salt, chk = m.group("salt", "chk")
return cls(salt=salt, checksum=chk)
def to_string(self):
hash = u("%s%s") % (self.salt, self.checksum)
return uascii_to_str(hash)
#===================================================================
# backend
#===================================================================
def _calc_checksum(self, secret):
if isinstance(secret, unicode):
secret = secret.encode("utf-8")
# check for truncation (during .hash() calls only)
if self.use_defaults:
self._check_truncate_policy(secret)
# parse salt value
try:
salt_value = h64.decode_int12(self.salt.encode("ascii"))
except ValueError: # pragma: no cover - caught by class
raise suppress_cause(ValueError("invalid chars in salt"))
# convert first 8 byts of secret string into an integer,
key1 = _crypt_secret_to_key(secret)
# run data through des using input of 0
result1 = des_encrypt_int_block(key1, 0, salt_value, 20)
# convert next 8 bytes of secret string into integer (key=0 if secret < 8 chars)
key2 = _crypt_secret_to_key(secret[8:16])
# run data through des using input of 0
result2 = des_encrypt_int_block(key2, 0, salt_value, 5)
# done
chk = h64big.encode_int64(result1) + h64big.encode_int64(result2)
return chk.decode("ascii")
#===================================================================
# eoc
#===================================================================
#=============================================================================
# eof
#=============================================================================