3
y�_s � @ sH d dl mZmZmZ d dlmZ d dlmZ dZdZ G dd� de
�Z dS ) � )�absolute_import�division�print_function)�InvalidSignature)�
constant_time� � c @ s, e Zd Zdd� Zdd� Zdd� Zdd� Zd S )
�_Poly1305Contextc C s� || _ | j jj|�}| j jj| j jj| j jj|t|��}| j j|| j jjk� | j jj || j jj
�| _ | j jj � }| j j|| j jjk� | j jj || j jj
�| _| j jj| j| j jj| j jj| j jj| j �}| j j|dk� d S )N� )�_backend�_ffi� from_buffer�_libZ EVP_PKEY_new_raw_private_keyZ NID_poly1305ZNULL�len�openssl_assert�gcZ
EVP_PKEY_freeZ _evp_pkeyZCryptography_EVP_MD_CTX_newZ Cryptography_EVP_MD_CTX_free�_ctxZEVP_DigestSignInit)�selfZbackend�keyZkey_ptrZevp_pkeyZctx�res� r � /usr/lib64/python3.6/poly1305.py�__init__ s*
z_Poly1305Context.__init__c C s: | j jj|�}| j jj| j|t|��}| j j|dk� d S )Nr )r r r
r ZEVP_DigestSignUpdater r r )r �dataZdata_ptrr r r r �update/ s z_Poly1305Context.updatec C sp | j jjdt�}| j jjd�}| j jj| j||�}| j j|dk� | j j|d tk� | j jj|�d |d � S )Nzunsigned char[]zsize_t *r ) r r �new�_POLY1305_TAG_SIZEr ZEVP_DigestSignFinalr r �buffer)r ZbufZoutlenr r r r �finalize6 s z_Poly1305Context.finalizec C s | j � }tj||�s td��d S )Nz!Value did not match computed tag.)r r Zbytes_eqr )r �tagZmacr r r �verify> s z_Poly1305Context.verifyN)�__name__�
__module__� __qualname__r r r r r r r r r s r N) Z
__future__r r r Zcryptography.exceptionsr Z cryptography.hazmat.primitivesr r Z_POLY1305_KEY_SIZE�objectr r r r r � s