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    –BÞb‰(  ã                
   @   s  d Z ddlZddlmZ ddlmZmZmZ ddlm	Z	m
Z
mZ ddlmZ dZdeeef eeeeeeed
œdd„Zeeeeedœdd„Zeeef eeedœdd„Zeeef eeeeeef dœdd„Zeeef eeeeeeeeef d
œdd„Zeeef eedœdd„ZdS )z,Anything related to encryption / decryption.é    N)Úmd5)ÚAnyÚTupleÚUnioné   )Úb_Úord_Ústr_)ÚByteStringObjects    (¿N^NuŠAd NVÿú.. ¶Ðh>€/©þdSizT)ÚpasswordÚrevÚkeylenÚowner_entryÚp_entryÚ	id1_entryÚmetadata_encryptÚreturnc                 C   s¦   t t| ƒttƒ dd… ƒ}t|ƒ}| |j¡ t d|¡}	| |	¡ | |j¡ |dkrh|sh| d¡ | ¡ }
|dkršt	dƒD ]}t|
d|… ƒ ¡ }
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d|… S )z€
    Implementation of algorithm 3.2 of the PDF standard security handler.

    See section 3.5.2 of the PDF 1.6 reference.
    Né    z<ié   s   ÿÿÿÿé2   )
r   r	   Ú_encryption_paddingr   ÚupdateÚoriginal_bytesÚstructÚpackÚdigestÚrange)r   r   r   r   r   r   r   Úpassword_bytesÚmZp_entry_bytesÚmd5_hashÚ_© r!   ú4/tmp/pip-unpacked-wheel-weujb6sz/PyPDF2/_security.pyÚ_alg32/   s    

r#   )Ú	owner_pwdÚuser_pwdr   r   r   c           
      C   sv   t | ||ƒ}t|ttƒ dd… ƒ}t||ƒ}|dkrrtddƒD ]0}d}|D ]}	|tt|	ƒ|A ƒ7 }qLt||ƒ}q@|S )z{
    Implementation of algorithm 3.3 of the PDF standard security handler,
    section 3.5.2 of the PDF 1.6 reference.
    Nr   r   r   é   Ú )Ú_alg33_1r   r	   r   ÚRC4_encryptr   Úchrr   )
r$   r%   r   r   ÚkeyZuser_pwd_bytesÚvalÚiÚnew_keyZkey_charr!   r!   r"   Ú_alg33e   s    
r/   )r   r   r   r   c                 C   sl   t | tƒr|  ¡ } t| ttƒ dd… ƒ}t|ƒ}| ¡ }|dkr\tdƒD ]}t|ƒ ¡ }qJ|d|… }|S )zSteps 1-4 of algorithm 3.3Nr   r   r   )	Ú
isinstanceÚbytesÚdecoder   r	   r   r   r   r   )r   r   r   r   r   r   r    r+   r!   r!   r"   r(   ƒ   s    
r(   )r   r   r   r   r   c                 C   s,   d}d}t | |||||ƒ}t|tƒ}||fS )ú€
    Implementation of algorithm 3.4 of the PDF standard security handler.

    See section 3.5.2 of the PDF 1.6 reference.
    é   é   )r#   r)   r   )r   r   r   r   r   r   r+   ÚUr!   r!   r"   Ú_alg34œ   s
    
r7   c                 C   sŒ   t | |||||ƒ}tƒ }| t¡ | |j¡ | ¡ }	t||	ƒ}
tddƒD ]4}d}|D ]}|tt	t
|ƒ|A ƒƒ7 }qVt||
ƒ}
qJ|
d |fS )r3   r   r&   ó    s                   )r#   r   r   r   r   r   r)   r   r   r*   r   )r   r   r   r   r   r   r   r+   r   r   r,   r-   r.   Úkr!   r!   r"   Ú_alg35µ   s    

r:   )r+   Ú	plaintextr   c                 C   sä   t tdƒƒ}d}tdƒD ]B}|||  t| |t| ƒ  ƒ d }|| ||  ||< ||< qd\}}g }|D ]l}|d d }|||  d }|| ||  ||< ||< ||| ||  d  }| ttt|ƒ|A ƒƒ¡ qld |¡S )Né   r   )r   r   r   r8   )Úlistr   r   ÚlenÚappendr   r*   Újoin)r+   r;   ÚSÚjr-   ÚretvalZplaintext_charÚtr!   r!   r"   r)   ç   s    $r)   )T)Ú__doc__r   Úhashlibr   Útypingr   r   r   Ú_utilsr   r   r	   Zgenericr
   r   Ústrr1   ÚintÚboolr#   r/   r(   r7   r:   r)   r!   r!   r!   r"   Ú<module>   sH   ÿ ù
ø6

û

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