"""passlib.handlers.digests - plain hash digests
"""
#=============================================================================
# imports
#=============================================================================
# core
import hashlib
import logging; log = logging.getLogger(__name__)
# site
# pkg
from passlib.utils import to_native_str, to_bytes, render_bytes, consteq
from passlib.utils.compat import unicode, str_to_uascii
import passlib.utils.handlers as uh
from passlib.crypto.digest import lookup_hash
# local
__all__ = [
"create_hex_hash",
"hex_md4",
"hex_md5",
"hex_sha1",
"hex_sha256",
"hex_sha512",
]
#=============================================================================
# helpers for hexadecimal hashes
#=============================================================================
class HexDigestHash(uh.StaticHandler):
"""this provides a template for supporting passwords stored as plain hexadecimal hashes"""
#===================================================================
# class attrs
#===================================================================
_hash_func = None # hash function to use - filled in by create_hex_hash()
checksum_size = None # filled in by create_hex_hash()
checksum_chars = uh.HEX_CHARS
#===================================================================
# methods
#===================================================================
@classmethod
def _norm_hash(cls, hash):
return hash.lower()
def _calc_checksum(self, secret):
if isinstance(secret, unicode):
secret = secret.encode("utf-8")
return str_to_uascii(self._hash_func(secret).hexdigest())
#===================================================================
# eoc
#===================================================================
def create_hex_hash(digest, module=__name__):
# NOTE: could set digest_name=hash.name for cpython, but not for some other platforms.
info = lookup_hash(digest)
name = "hex_" + info.name
return type(name, (HexDigestHash,), dict(
name=name,
__module__=module, # so ABCMeta won't clobber it
_hash_func=staticmethod(info.const), # sometimes it's a function, sometimes not. so wrap it.
checksum_size=info.digest_size*2,
__doc__="""This class implements a plain hexadecimal %s hash, and follows the :ref:`password-hash-api`.
It supports no optional or contextual keywords.
""" % (info.name,)
))
#=============================================================================
# predefined handlers
#=============================================================================
hex_md4 = create_hex_hash("md4")
hex_md5 = create_hex_hash("md5")
hex_md5.django_name = "unsalted_md5"
hex_sha1 = create_hex_hash("sha1")
hex_sha256 = create_hex_hash("sha256")
hex_sha512 = create_hex_hash("sha512")
#=============================================================================
# htdigest
#=============================================================================
class htdigest(uh.MinimalHandler):
"""htdigest hash function.
.. todo::
document this hash
"""
name = "htdigest"
setting_kwds = ()
context_kwds = ("user", "realm", "encoding")
default_encoding = "utf-8"
@classmethod
def hash(cls, secret, user, realm, encoding=None):
# NOTE: this was deliberately written so that raw bytes are passed through
# unchanged, the encoding kwd is only used to handle unicode values.
if not encoding:
encoding = cls.default_encoding
uh.validate_secret(secret)
if isinstance(secret, unicode):
secret = secret.encode(encoding)
user = to_bytes(user, encoding, "user")
realm = to_bytes(realm, encoding, "realm")
data = render_bytes("%s:%s:%s", user, realm, secret)
return hashlib.md5(data).hexdigest()
@classmethod
def _norm_hash(cls, hash):
"""normalize hash to native string, and validate it"""
hash = to_native_str(hash, param="hash")
if len(hash) != 32:
raise uh.exc.MalformedHashError(cls, "wrong size")
for char in hash:
if char not in uh.LC_HEX_CHARS:
raise uh.exc.MalformedHashError(cls, "invalid chars in hash")
return hash
@classmethod
def verify(cls, secret, hash, user, realm, encoding="utf-8"):
hash = cls._norm_hash(hash)
other = cls.hash(secret, user, realm, encoding)
return consteq(hash, other)
@classmethod
def identify(cls, hash):
try:
cls._norm_hash(hash)
except ValueError:
return False
return True
@uh.deprecated_method(deprecated="1.7", removed="2.0")
@classmethod
def genconfig(cls):
return cls.hash("", "", "")
@uh.deprecated_method(deprecated="1.7", removed="2.0")
@classmethod
def genhash(cls, secret, config, user, realm, encoding=None):
# NOTE: 'config' is ignored, as this hash has no salting / other configuration.
# just have to make sure it's valid.
cls._norm_hash(config)
return cls.hash(secret, user, realm, encoding)
#=============================================================================
# eof
#=============================================================================