codekingpro/portable-devtools

1"""passlib.pbkdf2 - PBKDF2 support2 3this module is getting increasingly poorly named.4maybe rename to "kdf" since it's getting more key derivation functions added.5"""6#=============================================================================7# imports8#=============================================================================9from __future__ import division10# core11import logging; log = logging.getLogger(__name__)12# site13# pkg14from passlib.exc import ExpectedTypeError15from passlib.utils.decor import deprecated_function16from passlib.utils.compat import native_string_types17from passlib.crypto.digest import norm_hash_name, lookup_hash, pbkdf1 as _pbkdf1, pbkdf2_hmac, compile_hmac18# local19__all__ = [20    # hash utils21    "norm_hash_name",22 23    # prf utils24    "get_prf",25 26    # kdfs27    "pbkdf1",28    "pbkdf2",29]30 31#=============================================================================32# issue deprecation warning for module33#=============================================================================34from warnings import warn35 36warn("the module 'passlib.utils.pbkdf2' is deprecated as of Passlib 1.7, "37     "and will be removed in Passlib 2.0, please use 'passlib.crypto' instead",38     DeprecationWarning)39 40#=============================================================================41# hash helpers42#=============================================================================43 44norm_hash_name = deprecated_function(deprecated="1.7", removed="1.8", func_module=__name__,45    replacement="passlib.crypto.digest.norm_hash_name")(norm_hash_name)46 47#=============================================================================48# prf lookup49#=============================================================================50 51#: cache mapping prf name/func -> (func, digest_size)52_prf_cache = {}53 54#: list of accepted prefixes55_HMAC_PREFIXES = ("hmac_", "hmac-")56 57def get_prf(name):58    """Lookup pseudo-random family (PRF) by name.59 60    :arg name:61        This must be the name of a recognized prf.62        Currently this only recognizes names with the format63        :samp:`hmac-{digest}`, where :samp:`{digest}`64        is the name of a hash function such as65        ``md5``, ``sha256``, etc.66 67        todo: restore text about callables.68 69    :raises ValueError: if the name is not known70    :raises TypeError: if the name is not a callable or string71 72    :returns:73        a tuple of :samp:`({prf_func}, {digest_size})`, where:74 75        * :samp:`{prf_func}` is a function implementing76          the specified PRF, and has the signature77          ``prf_func(secret, message) -> digest``.78 79        * :samp:`{digest_size}` is an integer indicating80          the number of bytes the function returns.81 82    Usage example::83 84        >>> from passlib.utils.pbkdf2 import get_prf85        >>> hmac_sha256, dsize = get_prf("hmac-sha256")86        >>> hmac_sha25687        <function hmac_sha256 at 0x1e37c80>88        >>> dsize89        3290        >>> digest = hmac_sha256('password', 'message')91 92    .. deprecated:: 1.793 94        This function is deprecated, and will be removed in Passlib 2.0.95        This only related replacement is :func:`passlib.crypto.digest.compile_hmac`.96    """97    global _prf_cache98    if name in _prf_cache:99        return _prf_cache[name]100    if isinstance(name, native_string_types):101        if not name.startswith(_HMAC_PREFIXES):102            raise ValueError("unknown prf algorithm: %r" % (name,))103        digest = lookup_hash(name[5:]).name104        def hmac(key, msg):105            return compile_hmac(digest, key)(msg)106        record = (hmac, hmac.digest_info.digest_size)107    elif callable(name):108        # assume it's a callable, use it directly109        digest_size = len(name(b'x', b'y'))110        record = (name, digest_size)111    else:112        raise ExpectedTypeError(name, "str or callable", "prf name")113    _prf_cache[name] = record114    return record115 116#=============================================================================117# pbkdf1 support118#=============================================================================119def pbkdf1(secret, salt, rounds, keylen=None, hash="sha1"):120    """pkcs#5 password-based key derivation v1.5121 122    :arg secret: passphrase to use to generate key123    :arg salt: salt string to use when generating key124    :param rounds: number of rounds to use to generate key125    :arg keylen: number of bytes to generate (if ``None``, uses digest's native size)126    :param hash:127        hash function to use. must be name of a hash recognized by hashlib.128 129    :returns:130        raw bytes of generated key131 132    .. note::133 134        This algorithm has been deprecated, new code should use PBKDF2.135        Among other limitations, ``keylen`` cannot be larger136        than the digest size of the specified hash.137 138    .. deprecated:: 1.7139 140        This has been relocated to :func:`passlib.crypto.digest.pbkdf1`,141        and this version will be removed in Passlib 2.0.142        *Note the call signature has changed.*143    """144    return _pbkdf1(hash, secret, salt, rounds, keylen)145 146#=============================================================================147# pbkdf2148#=============================================================================149def pbkdf2(secret, salt, rounds, keylen=None, prf="hmac-sha1"):150    """pkcs#5 password-based key derivation v2.0151 152    :arg secret:153        passphrase to use to generate key154 155    :arg salt:156        salt string to use when generating key157 158    :param rounds:159        number of rounds to use to generate key160 161    :arg keylen:162        number of bytes to generate.163        if set to ``None``, will use digest size of selected prf.164 165    :param prf:166        psuedo-random family to use for key strengthening.167        this must be a string starting with ``"hmac-"``, followed by the name of a known digest.168        this defaults to ``"hmac-sha1"`` (the only prf explicitly listed in169        the PBKDF2 specification)170 171        .. rst-class:: warning172 173        .. versionchanged 1.7:174 175            This argument no longer supports arbitrary PRF callables --176            These were rarely / never used, and created too many unwanted codepaths.177 178    :returns:179        raw bytes of generated key180 181    .. deprecated:: 1.7182 183        This has been deprecated in favor of :func:`passlib.crypto.digest.pbkdf2_hmac`,184        and will be removed in Passlib 2.0.  *Note the call signature has changed.*185    """186    if callable(prf) or (isinstance(prf, native_string_types) and not prf.startswith(_HMAC_PREFIXES)):187        raise NotImplementedError("non-HMAC prfs are not supported as of Passlib 1.7")188    digest = prf[5:]189    return pbkdf2_hmac(digest, secret, salt, rounds, keylen)190 191#=============================================================================192# eof193#=============================================================================194