U
    *}f                     @   s   d dl mZmZmZ d dlmZ d dl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mZmZ d d	lmZ G d
d deZG dd deZe	eG dd deZdS )    )absolute_importdivisionprint_function)Enum)range)utils)AlreadyFinalized
InvalidKeyUnsupportedAlgorithm_Reasons)_get_backend)HMACBackend)constant_timehasheshmac)KeyDerivationFunctionc                   @   s   e Zd ZdZdS )ModeZctrN)__name__
__module____qualname__ZCounterMode r   r   L/tmp/pip-unpacked-wheel-x36vw73o/cryptography/hazmat/primitives/kdf/kbkdf.pyr      s   r   c                   @   s   e Zd ZdZdZdS )CounterLocationZbefore_fixedZafter_fixedN)r   r   r   BeforeFixed
AfterFixedr   r   r   r   r      s   r   c                   @   s6   e Zd ZdddZdd Zdd Zdd	 Zd
d ZdS )	KBKDFHMACNc                 C   sF  t |
}
t|
tstdtjt|tjs6tdtj|
	|sLtdtjt|t
s^tdt|tsptd|sx|r|	rtd|d ks| |std|d kr|	d krtd|d k	rt|tstd	|d krd
}|d krd
}td| td| || _|| _|| _|| _|| _|| _|| _|| _|
| _d| _|	| _d S )Nz.Backend object does not implement HMACBackend.z5Algorithm supplied is not a supported hash algorithm.z5Algorithm supplied is not a supported hmac algorithm.zmode must be of type Modez(location must be of type CounterLocationz9When supplying fixed data, label and context are ignored.zrlen must be between 1 and 4zPlease specify an llenzllen must be an integer    labelcontextF)r   
isinstancer   r
   r   ZBACKEND_MISSING_INTERFACEr   ZHashAlgorithmZUNSUPPORTED_HASHZhmac_supportedr   	TypeErrorr   
ValueError_valid_byte_lengthintr   _check_bytes
_algorithm_mode_length_rlen_llen	_location_label_context_backend_used_fixed_data)self	algorithmmodelengthZrlenZllenlocationr   r   Zfixedbackendr   r   r   __init__#   s^    



zKBKDFHMAC.__init__c                 C   s@   t |tstdtd|}dt|  kr6dks<n dS dS )Nzvalue must be of type int      FT)r   r#   r    r   int_to_byteslen)r0   valueZ	value_binr   r   r   r"   k   s    
zKBKDFHMAC._valid_byte_lengthc                 C   s   | j r
ttd| d| _ | j | jj  }dg}td| j}|t	dt
|d d krdtdtd|d D ]n}tj|| j| jd}t|| j}| jtjkr|| ||   | jtjkr|| ||  qrd|d | j S )	Nkey_materialTr   r7         zThere are too many iterations.)r5   )r.   r   r   Z_check_bytesliker'   r%   digest_sizer9   r(   powr:   r!   r   r   HMACr-   r*   r   r   update_generate_fixed_inputr   appendfinalizejoin)r0   r<   roundsoutputZr_binihcounterr   r   r   derivet   s&    

zKBKDFHMAC.derivec                 C   sB   | j rt| j tr| j S t| jd | j}d| jd| j	|gS )Nr>   r       )
r/   r   bytesr   r9   r'   r)   rF   r+   r,   )r0   Zl_valr   r   r   rC      s    zKBKDFHMAC._generate_fixed_inputc                 C   s   t | ||std S )N)r   Zbytes_eqrL   r	   )r0   r<   Zexpected_keyr   r   r   verify   s    zKBKDFHMAC.verify)N)r   r   r   r6   r"   rL   rC   rO   r   r   r   r   r   !   s    
H	$r   N)
__future__r   r   r   enumr   Z	six.movesr   Zcryptographyr   Zcryptography.exceptionsr   r	   r
   r   Zcryptography.hazmat.backendsr   Z'cryptography.hazmat.backends.interfacesr   Zcryptography.hazmat.primitivesr   r   r   Z"cryptography.hazmat.primitives.kdfr   r   r   Zregister_interfaceobjectr   r   r   r   r   <module>   s   