3
l�_� � @ sd d dl mZmZmZ d dlmZ dZd Zdd� Zdd� Z dd � Z
d
d � Z d d
� Z dd� Z
dd� ZdS )� )�absolute_import�division�print_function)�
InvalidTag� c C sr ddl m}m}m} t| |�r"dS t| |�rFdjt| j�d �jd�S t| |�sTt �djt| j�d �jd�S d S )Nr )�AESCCM�AESGCM�ChaCha20Poly1305s chacha20-poly1305z
aes-{}-ccm� �asciiz
aes-{}-gcm)
�+cryptography.hazmat.primitives.ciphers.aeadr r r �
isinstance�format�len�_key�encode�AssertionError)�cipherr r r � r � /usr/lib64/python3.6/aead.py�_aead_cipher_name s
r c C st | j j|�}| j|| jjk� | j j� }| jj|| j j�}| j j||| jj| jj| jjt |t
k��} | j| dk� | j j |t |��} | j| dk� | j j
|| j jt |�| jj�} | j| dk� |tkr�| j j
|| j jt |�|�} | j| dk� n4|jd��r$| j j
|| j j|| jj�} | j| dk� | jj|�}
| jj|�} | j j|| jj| jj| |
t |t
k��} | j| dk� |S )Nr s -ccm)�_libZEVP_get_cipherbyname�openssl_assert�_ffi�NULLZEVP_CIPHER_CTX_new�gcZEVP_CIPHER_CTX_freeZEVP_CipherInit_ex�int�_ENCRYPTZ EVP_CIPHER_CTX_set_key_lengthr �EVP_CIPHER_CTX_ctrlZEVP_CTRL_AEAD_SET_IVLEN�_DECRYPTZEVP_CTRL_AEAD_SET_TAG�endswithZ from_buffer) �backend� cipher_name�key�nonce�tagZtag_lenZ operationZ
evp_cipher�ctx�resZ nonce_ptrZkey_ptrr r r � _aead_setup sN
r( c C s: | j jd�}| jj|| j j|| j j|�}| j|dk� d S )Nzint *r )r �newr �EVP_CipherUpdater r )r! r& Zdata_lenZintptrr' r r r � _set_lengthN s r+ c C s: | j jd�}| jj|| j j||t|��}| j|dk� d S )Nzint *r )r r) r r* r r r )r! r& �associated_data�outlenr' r r r � _process_aadV s r. c C s^ | j jd�}| j jdt|��}| jj||||t|��}| j|dk� | j j||d �d d � S )Nzint *zunsigned char[]r )r r) r r r* r �buffer)r! r& �datar- �bufr' r r r �
_process_data^ s
r2 c C s� ddl m} t|�}t| ||j|d |t�}t||�rDt| |t|�� t | ||� t
| ||�} | j j d�}
| j
j|| j j|
�} | j| dk� | j|
d dk� | j j d|�} | j
j|| j
j|| �} | j| dk� | j j| �d d � }
| |
S )Nr )r zint *zunsigned char[])r r r r( r r r
r+ r r. r2 r r) r �EVP_CipherFinal_exr r r ZEVP_CTRL_AEAD_GET_TAGr/ )r! r r$ r0 r, �
tag_lengthr r" r& �processed_datar- r' Ztag_bufr% r r r �_encryptf s$
r6 c C s2 ddl m} t|�|k r t�|| d � }|d | � }t|�}t| ||j|||t�} t||�rpt | | t|�� t
| | |� t||�r�| j j d�}
| j j dt|��} | j
j| | |
|t|��} | dkr�| j� t�| j j| |
d �d d � }
nBt| | |�}
| j j d�}
| j
j| | j j|
�} | dk�r.| j� t�|
S )Nr )r zint *zunsigned char[]r )r r r r r r( r r r
r+ r. r r) r r* Z_consume_errorsr/ r2 r3 r )r! r r$ r0 r, r4 r r% r" r& r- r1 r' r5 r r r �_decrypt� s4
r7 N)Z
__future__r r r Zcryptography.exceptionsr r r r r( r+ r. r2 r6 r7 r r r r � s 0