o
    )%au                     @   sF   d dl mZ d dlmZmZmZ d dlmZmZ G dd dej	Z
dS )    )utils)InvalidSignatureUnsupportedAlgorithm_Reasons)constant_timehashesc                   @   sj   e Zd Z	ddedejfddZedZ	ddd	Z
d
eddfddZdefddZdeddfddZdS )_HMACContextNkey	algorithmc                 C   s   || _ || _|d u r\| jj }| j|| jjjk | jj|| jjj}| j	|}|| jjjkr=t
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_free_evp_md_from_algorithmr   formatnamer   UNSUPPORTED_HASHfrom_bufferHMAC_Init_exlen_ctx_key)selfbackendr	   r
   ctxevp_mdkey_ptrres r#   K/usr/lib/python3/dist-packages/cryptography/hazmat/backends/openssl/hmac.py__init__   s*   
z_HMACContext.__init__r   returnc                 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   HMAC_CTX_copyr   r   r   r
   )r   
copied_ctxr"   r#   r#   r$   copy-   s   
z_HMACContext.copydatac                 C   s:   | j j|}| j j| j|t|}| j |dk d S )Nr   )r   r   r   r   HMAC_Updater   r   r   )r   r*   data_ptrr"   r#   r#   r$   update9   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   EVP_MAX_MD_SIZE
HMAC_Finalr   r   r
   digest_sizebuffer)r   bufoutlenr"   r#   r#   r$   finalize>   s   
z_HMACContext.finalize	signaturec                 C   s    |   }t||stdd S )NzSignature did not match digest.)r5   r   bytes_eqr   )r   r6   digestr#   r#   r$   verifyH   s   z_HMACContext.verify)N)r&   r   )__name__
__module____qualname__bytesr   HashAlgorithmr%   r   read_only_propertyr
   r)   r-   r5   r9   r#   r#   r#   r$   r      s    



r   N)cryptographyr   cryptography.exceptionsr   r   r   cryptography.hazmat.primitivesr   r   HashContextr   r#   r#   r#   r$   <module>   s   