o
    b                     @   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deddfddZdefd	d
Z	dddZ
deddfddZdS )_CMACContextNc           	      C   s   | |stdtj|| _|j| _|| _|jd | _	|d u ro| 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_freefrom_bufferZ	CMAC_Initlen_ctx)	selfbackend	algorithmctxregistryadapterZ
evp_cipherZkey_ptrres r"   h/var/www/secure340b-portal/env/lib/python3.10/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.updatec                 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	signaturec                 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)r&   r   )__name__
__module____qualname__r$   r   Zread_only_propertyr   bytesr'   r,   r-   r0   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
   