U
    [e                     @   sL   d dl mZ d dlmZmZmZ d dlmZ d dlm	Z	 G dd de
ZdS )    )utils)InvalidSignatureUnsupportedAlgorithm_Reasons)constant_time)CBCc                   @   s\   e Zd ZdddZedZeddddZedd	d
Z	d dddZ
eddddZdS )_CMACContextNc           	      C   s   | |stdtj|| _|j| _|| _|jd | _	|d kr| jj
}|t|tf }|| j|t}| jj }| j|| jjjk | jj|| jjj}| jj| j}| jj||t| j|| jjj}| j|dk || _d S )Nz#This backend does not support CMAC.      )Zcmac_algorithm_supportedr   r   ZUNSUPPORTED_CIPHER_backendkey_key
_algorithm
block_size_output_lengthZ_cipher_registrytyper   _libCMAC_CTX_newopenssl_assert_ffiZNULLgcCMAC_CTX_freeZfrom_bufferZ	CMAC_Initlen_ctx)	selfbackend	algorithmctxregistryadapterZ
evp_cipherZkey_ptrres r!   k/var/www/html/services/stratfitenv/lib/python3.8/site-packages/cryptography/hazmat/backends/openssl/cmac.py__init__   s4    
z_CMACContext.__init__r   )datareturnc                 C   s,   | j j| j|t|}| j |dk d S )Nr
   )r   r   ZCMAC_Updater   r   r   )r   r$   r    r!   r!   r"   update6   s    z_CMACContext.update)r%   c                 C   sd   | j jd| j}| j jd| j}| j j| j||}| j |dk d | _| j j|d d  S )Nzunsigned char[]zsize_t *r
   )	r   r   newr   r   Z
CMAC_Finalr   r   buffer)r   buflengthr    r!   r!   r"   finalize:   s    z_CMACContext.finalizec                 C   sV   | j j }| j j|| j jj}| j j|| j}| j |dk t	| j | j
|dS )Nr
   )r   )r   r   r   r   r   r   ZCMAC_CTX_copyr   r   r   r   )r   Z
copied_ctxr    r!   r!   r"   copyD   s     z_CMACContext.copy)	signaturer%   c                 C   s    |   }t||stdd S )NzSignature did not match digest.)r+   r   Zbytes_eqr   )r   r-   digestr!   r!   r"   verifyM   s    z_CMACContext.verify)N)__name__
__module____qualname__r#   r   Zread_only_propertyr   bytesr&   r+   r,   r/   r!   r!   r!   r"   r      s   
#

	r   N)Zcryptographyr   Zcryptography.exceptionsr   r   r   Zcryptography.hazmat.primitivesr   Z,cryptography.hazmat.primitives.ciphers.modesr   objectr   r!   r!   r!   r"   <module>   s   