def get_prf(name):
"""lookup pseudo-random family (prf) by name.
:arg name:
this must be the name of a recognized prf.
currently this only recognizes names with the format
:samp:`hmac-{digest}`, where :samp:`{digest}`
is the name of a hash function such as
``md5``, ``sha256``, etc.
this can also be a callable with the signature
``prf(secret, message) -> digest``,
in which case it will be returned unchanged.
:raises ValueError: if the name is not known
:raises TypeError: if the name is not a callable or string
:returns:
a tuple of :samp:`({func}, {digest_size})`.
* :samp:`{func}` is a function implementing
the specified prf, and has the signature
``func(secret, message) -> digest``.
* :samp:`{digest_size}` is an integer indicating
the number of bytes the function returns.
usage example::
>>> from passlib.utils.pbkdf2 import get_prf
>>> hmac_sha256, dsize = get_prf("hmac-sha256")
>>> hmac_sha256
<function hmac_sha256 at 0x1e37c80>
>>> dsize
32
>>> digest = hmac_sha256('password', 'message')
this function will attempt to return the fastest implementation
it can find; if M2Crypto is present, and supports the specified prf,
:func:`M2Crypto.EVP.hmac` will be used behind the scenes.
"""
global _prf_cache
if name in _prf_cache:
return _prf_cache[name]
if isinstance(name, str):
if name.startswith("hmac-") or name.startswith("hmac_"):
retval = _get_hmac_prf(name[5:])
else:
raise ValueError("unknown prf algorithm: %r" % (name,))
elif callable(name):
# assume it's a callable, use it directly
digest_size = len(name(b('x'),b('y')))
retval = (name, digest_size)
else:
raise ExpectedTypeError(name, "str or callable", "prf name")
_prf_cache[name] = retval
return retval
def get_prf(name):
"""lookup pseudo-random family (prf) by name.
:arg name:
this must be the name of a recognized prf.
currently this only recognizes names with the format
:samp:`hmac-{digest}`, where :samp:`{digest}`
is the name of a hash function such as
``md5``, ``sha256``, etc.
this can also be a callable with the signature
``prf(secret, message) -> digest``,
in which case it will be returned unchanged.
:raises ValueError: if the name is not known
:raises TypeError: if the name is not a callable or string
:returns:
a tuple of :samp:`({func}, {digest_size})`.
* :samp:`{func}` is a function implementing
the specified prf, and has the signature
``func(secret, message) -> digest``.
* :samp:`{digest_size}` is an integer indicating
the number of bytes the function returns.
usage example::
>>> from passlib.utils.pbkdf2 import get_prf
>>> hmac_sha256, dsize = get_prf("hmac-sha256")
>>> hmac_sha256
<function hmac_sha256 at 0x1e37c80>
>>> dsize
32
>>> digest = hmac_sha256('password', 'message')
this function will attempt to return the fastest implementation
it can find; if M2Crypto is present, and supports the specified prf,
:func:`M2Crypto.EVP.hmac` will be used behind the scenes.
"""
global _prf_cache
if name in _prf_cache:
return _prf_cache[name]
if isinstance(name, str):
if name.startswith("hmac-") or name.startswith("hmac_"):
retval = _get_hmac_prf(name[5:])
else:
raise ValueError("unknown prf algorithm: %r" % (name,))
elif callable(name):
# assume it's a callable, use it directly
digest_size = len(name(b('x'),b('y')))
retval = (name, digest_size)
else:
raise ExpectedTypeError(name, "str or callable", "prf name")
_prf_cache[name] = retval
return retval
def _load():
global _get_category
# TODO: would like to add support for inheriting config from a preset
# (or from existing hasher state) and letting PASSLIB_CONFIG
# be an update, not a replacement.
# TODO: wrap and import any custom hashers as passlib handlers,
# so they could be used in the passlib config.
# load config from settings
_UNSET = object()
config = getattr(settings, "PASSLIB_CONFIG", _UNSET)
if config is _UNSET:
# XXX: should probably deprecate this alias
config = getattr(settings, "PASSLIB_CONTEXT", _UNSET)
if config is _UNSET:
config = "passlib-default"
if config is None:
warn(
"setting PASSLIB_CONFIG=None is deprecated, "
"and support will be removed in Passlib 1.8, "
"use PASSLIB_CONFIG='disabled' instead.", DeprecationWarning)
config = "disabled"
elif not isinstance(config, (unicode, bytes, dict)):
raise ExpectedTypeError(config, "str or dict", "PASSLIB_CONFIG")
# load custom category func (if any)
get_category = getattr(settings, "PASSLIB_GET_CATEGORY", None)
if get_category and not callable(get_category):
raise ExpectedTypeError(get_category, "callable",
"PASSLIB_GET_CATEGORY")
# check if we've been disabled
if config == "disabled":
if _patched: # pragma: no cover -- sanity check
log.error("didn't expect monkeypatching would be applied!")
_remove_patch()
return
# resolve any preset aliases
if isinstance(config, str) and '\n' not in config:
config = get_preset_config(config)
# setup context
_apply_patch()
password_context.load(config)
if get_category:
# NOTE: _get_category is module global which is read by
# monkeypatched functions constructed by _apply_patch()
_get_category = get_category
log.debug("passlib.ext.django loaded")
def _load():
global _get_category
# TODO: would like to add support for inheriting config from a preset
# (or from existing hasher state) and letting PASSLIB_CONFIG
# be an update, not a replacement.
# TODO: wrap and import any custom hashers as passlib handlers,
# so they could be used in the passlib config.
# load config from settings
_UNSET = object()
config = getattr(settings, "PASSLIB_CONFIG", _UNSET)
if config is _UNSET:
# XXX: should probably deprecate this alias
config = getattr(settings, "PASSLIB_CONTEXT", _UNSET)
if config is _UNSET:
config = "passlib-default"
if config is None:
warn("setting PASSLIB_CONFIG=None is deprecated, "
"and support will be removed in Passlib 1.8, "
"use PASSLIB_CONFIG='disabled' instead.",
DeprecationWarning)
config = "disabled"
elif not isinstance(config, (unicode, bytes, dict)):
raise ExpectedTypeError(config, "str or dict", "PASSLIB_CONFIG")
# load custom category func (if any)
get_category = getattr(settings, "PASSLIB_GET_CATEGORY", None)
if get_category and not callable(get_category):
raise ExpectedTypeError(get_category, "callable", "PASSLIB_GET_CATEGORY")
# check if we've been disabled
if config == "disabled":
if _patched: # pragma: no cover -- sanity check
log.error("didn't expect monkeypatching would be applied!")
_remove_patch()
return
# resolve any preset aliases
if isinstance(config, str) and '\n' not in config:
config = get_preset_config(config)
# setup context
_apply_patch()
password_context.load(config)
if get_category:
# NOTE: _get_category is module global which is read by
# monkeypatched functions constructed by _apply_patch()
_get_category = get_category
log.debug("passlib.ext.django loaded")
