U
    e]                     @   sl   d dl mZmZmZ d dlmZ d dlmZmZm	Z	 d dl
mZ d dlmZ eejG dd deZdS )	    )absolute_importdivisionprint_function)utils)AlreadyFinalizedUnsupportedAlgorithm_Reasons)HMACBackend)hashesc                   @   s@   e Zd ZdddZedZdd Zdd Zd	d
 Z	dd Z
dS )HMACNc                 C   sb   t |tstdtjt |tjs*td|| _|| _	|| _
|d krX| j	|| j| _n|| _d S )Nz.Backend object does not implement HMACBackend.z*Expected instance of hashes.HashAlgorithm.)
isinstancer	   r   r   ZBACKEND_MISSING_INTERFACEr
   ZHashAlgorithm	TypeError
_algorithm_backend_keyZcreate_hmac_ctx	algorithm_ctx)selfkeyr   backendctx r   E/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/hmac.py__init__   s    
zHMAC.__init__r   c                 C   s.   | j d krtdtd| | j | d S )NContext was already finalized.data)r   r   r   Z_check_byteslikeupdate)r   r   r   r   r   r   %   s    
zHMAC.updatec                 C   s.   | j d krtdt| j| j| j| j  dS )Nr   )r   r   )r   r   r   r   r   r   copy)r   r   r   r   r   +   s    
z	HMAC.copyc                 C   s&   | j d krtd| j  }d | _ |S )Nr   )r   r   finalize)r   Zdigestr   r   r   r   5   s
    

zHMAC.finalizec                 C   s:   t d| | jd krtd| jd  }| _|| d S )N	signaturer   )r   _check_bytesr   r   verify)r   r   r   r   r   r   r!   <   s
    
zHMAC.verify)N)__name__
__module____qualname__r   r   Zread_only_propertyr   r   r   r   r!   r   r   r   r   r      s   


r   N)Z
__future__r   r   r   Zcryptographyr   Zcryptography.exceptionsr   r   r   Z'cryptography.hazmat.backends.interfacesr	   Zcryptography.hazmat.primitivesr
   Zregister_interfaceZHashContextobjectr   r   r   r   r   <module>   s   
