ó
Õ{PXc           @` s§   d  d l  m Z m Z m Z d  d l m Z d  d l m Z m Z m	 Z	 m
 Z
 d  d l m Z d  d l m Z d  d l m Z e j e  d e f d     Y Z d	 S(
   i    (   t   absolute_importt   divisiont   print_function(   t   utils(   t   AlreadyFinalizedt
   InvalidKeyt   UnsupportedAlgorithmt   _Reasons(   t   ScryptBackend(   t   constant_time(   t   KeyDerivationFunctiont   Scryptc           B` s#   e  Z d    Z d   Z d   Z RS(   c         C` sę   t  | t  s$ t d t j   n  | |  _ t  | t  sK t d   n  | d k  sk | | d @d k rz t d   n  | d k  r t d   n  | d k  r° t d   n  t	 |  _
 | |  _ | |  _ | |  _ | |  _ | |  _ d  S(	   Ns0   Backend object does not implement ScryptBackend.s   salt must be bytes.i   i   i    s-   n must be greater than 1 and be a power of 2.s%   r must be greater than or equal to 1.s%   p must be greater than or equal to 1.(   t
   isinstanceR   R   R   t   BACKEND_MISSING_INTERFACEt   _lengtht   bytest	   TypeErrort
   ValueErrort   Falset   _usedt   _saltt   _nt   _rt   _pt   _backend(   t   selft   saltt   lengtht   nt   rt   pt   backend(    (    sM   /usr/lib/python2.7/dist-packages/cryptography/hazmat/primitives/kdf/scrypt.pyt   __init__   s&    	 					c         C` sm   |  j  r t d   n  t |  _  t | t  s? t d   n  |  j j | |  j |  j	 |  j
 |  j |  j  S(   Ns'   Scrypt instances can only be used once.s   key_material must be bytes.(   R   R   t   TrueR   R   R   R   t   derive_scryptR   R   R   R   R   (   R   t   key_material(    (    sM   /usr/lib/python2.7/dist-packages/cryptography/hazmat/primitives/kdf/scrypt.pyt   derive-   s    			c         C` s4   |  j  |  } t j | |  s0 t d   n  d  S(   Ns   Keys do not match.(   R$   R	   t   bytes_eqR   (   R   R#   t   expected_keyt   derived_key(    (    sM   /usr/lib/python2.7/dist-packages/cryptography/hazmat/primitives/kdf/scrypt.pyt   verify8   s    (   t   __name__t
   __module__R    R$   R(   (    (    (    sM   /usr/lib/python2.7/dist-packages/cryptography/hazmat/primitives/kdf/scrypt.pyR      s   		N(   t
   __future__R    R   R   t   cryptographyR   t   cryptography.exceptionsR   R   R   R   t'   cryptography.hazmat.backends.interfacesR   t   cryptography.hazmat.primitivesR	   t"   cryptography.hazmat.primitives.kdfR
   t   register_interfacet   objectR   (    (    (    sM   /usr/lib/python2.7/dist-packages/cryptography/hazmat/primitives/kdf/scrypt.pyt   <module>   s   "