U
    EZh                     @   sT   d dl Z d dlmZmZmZ d dlmZmZ e jr>d dl	m
Z
 G dd dejZdS )    N)InvalidSignatureUnsupportedAlgorithm_Reasons)constant_timehashes)Backendc                   @   sr   e Zd ZddeejdddZeejdddZd dd	d
Z	eddddZ
edddZeddddZdS )_HMACContextNr   )backendkey	algorithmc                 C   s   || _ || _|d kr| jj }| j|| jjjk | jj|| jjj}| j	|}|| jjjkrzt
d|jtj| jj|}| jj||t||| jjj}| j|dk || _|| _d S )Nz*{} is not a supported hash on this backendr   )
_algorithm_backend_libHMAC_CTX_newopenssl_assert_ffiNULLgcHMAC_CTX_freeZ_evp_md_from_algorithmr   formatnamer   ZUNSUPPORTED_HASHfrom_bufferZHMAC_Init_exlen_ctx_key)selfr	   r
   r   ctxZevp_mdZkey_ptrres r   p/home/aprabhat/apps/x.techxrdev.in/venv/lib/python3.8/site-packages/cryptography/hazmat/backends/openssl/hmac.py__init__   s2        z_HMACContext.__init__)returnc                 C   s   | j S )N)r   )r   r   r   r   r   2   s    z_HMACContext.algorithmc                 C   sp   | j j }| j || j jjk | j j|| j jj}| j j|| j	}| j |dk t
| j | j| j|dS )Nr   )r   )r   r   r   r   r   r   r   r   ZHMAC_CTX_copyr   r   r   r   )r   Z
copied_ctxr   r   r   r   copy6   s        z_HMACContext.copy)datar!   c                 C   s:   | j j|}| j j| j|t|}| j |dk d S )Nr   )r   r   r   r   ZHMAC_Updater   r   r   )r   r#   Zdata_ptrr   r   r   r   updateB   s    z_HMACContext.updatec                 C   sz   | j jd| j jj}| j jd}| j j| j||}| j |dk | j |d | jj	k | j j
|d |d  S )Nzunsigned char[]zunsigned int *r   )r   r   newr   ZEVP_MAX_MD_SIZEZ
HMAC_Finalr   r   r   digest_sizebuffer)r   bufZoutlenr   r   r   r   finalizeG   s     z_HMACContext.finalize)	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   verifyQ   s    z_HMACContext.verify)N)__name__
__module____qualname__bytesr   ZHashAlgorithmr    propertyr   r"   r$   r)   r,   r   r   r   r   r      s    
r   )typingZcryptography.exceptionsr   r   r   Zcryptography.hazmat.primitivesr   r   TYPE_CHECKINGZ,cryptography.hazmat.backends.openssl.backendr   ZHashContextr   r   r   r   r   <module>   s
   