B
    \                 @   s|   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mZ eejeejG dd deZdS )	    )absolute_importdivisionprint_function)utils)AlreadyFinalizedUnsupportedAlgorithm_Reasons)HMACBackend)hashesmacc               @   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   Blib/python3.7/site-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 )Nz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 )NzContext was already finalized.)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 )NzContext was already finalized.)r   r   finalize)r   Zdigestr   r   r   r   6   s
    

zHMAC.finalizec             C   s:   t d| | jd krtd| jd  }| _|| d S )N	signaturezContext was already finalized.)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
   r   Zregister_interfaceZ
MACContextZHashContextobjectr   r   r   r   r   <module>   s   
