U
    [+d=M                     @   s  d Z ddlZddlZddlmZ ddlmZ ddlmZ ddl	m
Z
mZ ddlmZ ddlmZ dd	lmZ dd
lmZ ddlmZmZ ddlmZ ddlmZ ddlmZ ddlmZ ddlm Z  e!dZ"e dZ#dZ$dZ%dZ&dZ'dZ(dZ)dZ*dZ+dZ,dZ-de- Z.ej/ej0 Z1dZ2dd  Z3d!d" Z4d#d$ Z5d%d& Z6d'd( Z7d)d* Z8d+d, Z9G d-d. d.e:Z;d/d0 Z<d1d2 Z=G d3d4 d4e:Z>G d5d6 d6eZ?dS )7z
Cross Site Request Forgery Middleware.

This module provides a middleware that implements protection
against request forgeries from other sites.
    N)defaultdicturlparse)settings)DisallowedHostImproperlyConfigured)UnreadablePostError)HttpHeaders)get_callable)patch_vary_headers)constant_time_compareget_random_string)MiddlewareMixin)cached_propertyis_same_domain)log_response)_lazy_re_compilezdjango.security.csrfz[^a-zA-Z0-9]z?Origin checking failed - %s does not match any trusted origins.z%Referer checking failed - no Referer.z@Referer checking failed - %s does not match any trusted origins.zCSRF cookie not set.zCSRF token missing.z/Referer checking failed - Referer is malformed.zCReferer checking failed - Referer is insecure while host is secure.zhas incorrect lengthzhas invalid characters       Z
_csrftokenc                   C   s
   t tjS )z/Return the view to be used for CSRF rejections.)r
   r   ZCSRF_FAILURE_VIEW r   r   :/tmp/pip-unpacked-wheel-n7e__lmp/django/middleware/csrf.py_get_failure_view2   s    r   c                   C   s   t ttdS )N)allowed_chars)r   CSRF_SECRET_LENGTHCSRF_ALLOWED_CHARSr   r   r   r   _get_new_csrf_string7   s    r   c                    sP   t  }t t fdd| D  fdd|D }d fdd|D }|| S )z
    Given a secret (assumed to be a string of CSRF_ALLOWED_CHARS), generate a
    token by adding a mask and applying it to the secret.
    c                 3   s   | ]}  |V  qd S Nindex.0xcharsr   r   	<genexpr>B   s     z&_mask_cipher_secret.<locals>.<genexpr> c                 3   s&   | ]\}} || t    V  qd S r   )lenr!   r"   yr#   r   r   r%   C   s     )r   r   zipjoin)secretmaskpairscipherr   r#   r   _mask_cipher_secret;   s
    &r0   c                    sZ   | dt  }| t d } t t fdd| D  fdd|D }d fdd|D S )z
    Given a token (assumed to be a string of CSRF_ALLOWED_CHARS, of length
    CSRF_TOKEN_LENGTH, and that its first half is a mask), use it to decrypt
    the second half to produce the original secret.
    Nc                 3   s   | ]}  |V  qd S r   r   r    r#   r   r   r%   P   s     z'_unmask_cipher_token.<locals>.<genexpr>r&   c                 3   s   | ]\}} ||  V  qd S r   r   r(   r#   r   r   r%   Q   s     )r   r   r*   r+   )tokenr-   r.   r   r#   r   _unmask_cipher_tokenG   s
    &r2   c                 C   s*   t  }| jtjrt|n|dd |S )zDGenerate a new random CSRF_COOKIE value, and add it to request.META.T)CSRF_COOKIECSRF_COOKIE_NEEDS_UPDATE)r   METAupdater   ZCSRF_COOKIE_MASKEDr0   requestcsrf_secretr   r   r   _add_new_csrf_cookieT   s    
r:   c                 C   s0   d| j kr | j d }d| j d< nt| }t|S )a  
    Return the CSRF token required for a POST form. The token is an
    alphanumeric value. A new token is created if one is not already set.

    A side effect of calling this function is to make the csrf_protect
    decorator and the CsrfViewMiddleware add a CSRF cookie and a 'Vary: Cookie'
    header to the outgoing response.  For this reason, you may need to use this
    function lazily, as is done by the csrf context processor.
    r3   Tr4   )r5   r:   r0   r7   r   r   r   	get_tokenf   s
    


r;   c                 C   s   t |  dS )zi
    Change the CSRF token in use for a request - should be done on login
    for security purposes.
    N)r:   )r8   r   r   r   rotate_token{   s    r<   c                   @   s   e Zd Zdd ZdS )InvalidTokenFormatc                 C   s
   || _ d S r   reasonselfr?   r   r   r   __init__   s    zInvalidTokenFormat.__init__N__name__
__module____qualname__rB   r   r   r   r   r=      s   r=   c                 C   s.   t | ttfkrttt| r*ttdS )z
    Raise an InvalidTokenFormat error if the token has an invalid length or
    characters that aren't allowed. The token argument can be a CSRF cookie
    secret or non-cookie CSRF token, and either masked or unmasked.
    N)r'   CSRF_TOKEN_LENGTHr   r=   REASON_INCORRECT_LENGTHinvalid_token_chars_researchREASON_INVALID_CHARACTERS)r1   r   r   r   _check_token_format   s    
rL   c                 C   s.   t | tkrt| } t | tks$tt| |S )a  
    Return whether the given CSRF token matches the given CSRF secret, after
    unmasking the token if necessary.

    This function assumes that the request_csrf_token argument has been
    validated to have the correct length (CSRF_SECRET_LENGTH or
    CSRF_TOKEN_LENGTH characters) and allowed characters, and that if it has
    length CSRF_TOKEN_LENGTH, it is a masked secret.
    )r'   rG   r2   r   AssertionErrorr   )request_csrf_tokenr9   r   r   r   _does_token_match   s    rO   c                   @   s   e Zd Zdd ZdS )RejectRequestc                 C   s
   || _ d S r   r>   r@   r   r   r   rB      s    zRejectRequest.__init__NrC   r   r   r   r   rP      s   rP   c                   @   s   e Zd ZdZedd Zedd Zedd Zdd	 Zd
d Z	dd Z
dd Zdd Zdd Zdd Zdd Zdd Zdd Zdd ZdS )CsrfViewMiddlewarez
    Require a present and correct csrfmiddlewaretoken for POST requests that
    have a CSRF cookie, and set an outgoing CSRF cookie.

    This middleware should be used in conjunction with the {% csrf_token %}
    template tag.
    c                 C   s   dd t jD S )Nc                 S   s   g | ]}t |jd qS *)r   netloclstripr!   originr   r   r   
<listcomp>   s   zACsrfViewMiddleware.csrf_trusted_origins_hosts.<locals>.<listcomp>r   CSRF_TRUSTED_ORIGINSrA   r   r   r   csrf_trusted_origins_hosts   s    z-CsrfViewMiddleware.csrf_trusted_origins_hostsc                 C   s   dd t jD S )Nc                 S   s   h | ]}d |kr|qS rR   r   rV   r   r   r   	<setcomp>   s      z;CsrfViewMiddleware.allowed_origins_exact.<locals>.<setcomp>rY   r[   r   r   r   allowed_origins_exact   s    z(CsrfViewMiddleware.allowed_origins_exactc                 C   s:   t t}dd tjD D ]}||j |jd q|S )z
        A mapping of allowed schemes to list of allowed netlocs, where all
        subdomains of the netloc are allowed.
        c                 s   s   | ]}d |krt |V  qdS )rS   Nr   rV   r   r   r   r%      s   z?CsrfViewMiddleware.allowed_origin_subdomains.<locals>.<genexpr>rS   )r   listr   rZ   schemeappendrT   rU   )rA   allowed_origin_subdomainsparsedr   r   r   rb      s    
z,CsrfViewMiddleware.allowed_origin_subdomainsc                 C   s
   d|_ d S )NT)csrf_processing_done)rA   r8   r   r   r   _accept   s    zCsrfViewMiddleware._acceptc                 C   s(   t  ||d}td||j||td |S )Nr>   zForbidden (%s): %s)responser8   logger)r   r   pathrg   )rA   r8   r?   rf   r   r   r   _reject   s    zCsrfViewMiddleware._rejectc                 C   s   t jr6z|jt}W qh tk
r2   tdY qhX n2z|jt j }W n t	k
r^   d}Y n
X t
| |dkrtdS t|tkrt|}|S )a  
        Return the CSRF secret originally associated with the request, or None
        if it didn't have one.

        If the CSRF_USE_SESSIONS setting is false, raises InvalidTokenFormat if
        the request's secret has invalid characters or an invalid length.
        zCSRF_USE_SESSIONS is enabled, but request.session is not set. SessionMiddleware must appear before CsrfViewMiddleware in MIDDLEWARE.N)r   CSRF_USE_SESSIONSsessiongetCSRF_SESSION_KEYAttributeErrorr   ZCOOKIESCSRF_COOKIE_NAMEKeyErrorrL   r'   rG   r2   rA   r8   r9   r   r   r   _get_secret   s"    
zCsrfViewMiddleware._get_secretc              
   C   sj   t jr.|jt|jd krf|jd |jt< n8|jt j|jd t jt j	t j
t jt jt jd t|d d S )Nr3   )Zmax_agedomainrh   securehttponlysamesite)Cookie)r   rj   rk   rl   rm   r5   
set_cookiero   ZCSRF_COOKIE_AGECSRF_COOKIE_DOMAINZCSRF_COOKIE_PATHZCSRF_COOKIE_SECUREZCSRF_COOKIE_HTTPONLYZCSRF_COOKIE_SAMESITEr   rA   r8   rf   r   r   r   _set_csrf_cookie  s    z#CsrfViewMiddleware._set_csrf_cookiec                    s   |j d }z| }W n tk
r*   Y n&X d| r:dnd|f }||krPdS || jkr^dS zt|}W n tk
r   Y dS X |j}|j t	 fdd| j
|d	D S )
NHTTP_ORIGINz%s://%shttpshttpTFc                 3   s   | ]}t  |V  qd S r   r   r!   hostZrequest_netlocr   r   r%   *  s   z6CsrfViewMiddleware._origin_verified.<locals>.<genexpr>r   )r5   get_hostr   	is_securer^   r   
ValueErrorr`   rT   anyrb   rl   )rA   r8   Zrequest_originZ	good_hostZgood_originZparsed_originZrequest_schemer   r   r   _origin_verified  s,    

z#CsrfViewMiddleware._origin_verifiedc                    s  |j d  d krttzt  W n tk
rD   ttY nX d j jfkr^tt jdkrptt	t
 fdd| jD rd S tjrtjntj}|d krz| }W q tk
r   tt   Y qX n| }|dkrd||f }t j|stt   d S )NZHTTP_REFERERr&   r}   c                 3   s   | ]}t  j|V  qd S r   )r   rT   r   Zrefererr   r   r%   A  s   z4CsrfViewMiddleware._check_referer.<locals>.<genexpr>)44380z%s:%s)r5   rl   rP   REASON_NO_REFERERr   r   REASON_MALFORMED_REFERERr`   rT   REASON_INSECURE_REFERERr   r\   r   rj   ZSESSION_COOKIE_DOMAINry   r   r   REASON_BAD_REFERERgeturlZget_portr   )rA   r8   Zgood_refererZserver_portr   r   r   _check_referer/  s:    
z!CsrfViewMiddleware._check_refererc                 C   s0   |dkrt |}d|d}d| d| dS )NPOSTzthe z HTTP headerzCSRF token from  .)r	   Zparse_header_name)rA   r?   token_sourceheader_namer   r   r   _bad_token_message\  s    
z%CsrfViewMiddleware._bad_token_messagec              
   C   s8  z|  |}W n4 tk
rB } ztd|j dW 5 d }~X Y nX |d krTttd}|jdkrz|jdd}W n tk
r   Y nX |dkrz|j	t
j }W n tk
r   ttY nX t
j}nd}zt| W n: tk
r } z| |j|}t|W 5 d }~X Y nX t||s4| d|}t|d S )NzCSRF cookie r   r&   r   ZcsrfmiddlewaretokenZ	incorrect)rr   r=   rP   r?   REASON_NO_CSRF_COOKIEmethodr   rl   r   r5   r   ZCSRF_HEADER_NAMErp   REASON_CSRF_TOKEN_MISSINGrL   r   rO   )rA   r8   r9   excrN   r   r?   r   r   r   _check_tokenc  s6    $
zCsrfViewMiddleware._check_tokenc                 C   sB   z|  |}W n tk
r*   t| Y nX |d k	r>||jd< d S )Nr3   )rr   r=   r:   r5   rq   r   r   r   process_request  s    z"CsrfViewMiddleware.process_requestc              
   C   s  t |ddrd S t |ddr d S |jdkr4| |S t |ddrJ| |S d|jkrv| |s| |t|jd  S nL| rz| | W n4 t	k
r } z| ||j
 W Y S d }~X Y nX z| | W n6 t	k
r } z| ||j
 W Y S d }~X Y nX | |S )Nrd   FZcsrf_exempt)GETHEADOPTIONSTRACEZ_dont_enforce_csrf_checksr|   )getattrr   re   r5   r   ri   REASON_BAD_ORIGINr   r   rP   r?   r   )rA   r8   callbackcallback_argscallback_kwargsr   r   r   r   process_view  s0    




 $$zCsrfViewMiddleware.process_viewc                 C   s&   |j dr"| || d|j d< |S )Nr4   F)r5   rl   r{   rz   r   r   r   process_response  s    
z#CsrfViewMiddleware.process_responseN)rD   rE   rF   __doc__r   r\   r^   rb   re   ri   rr   r{   r   r   r   r   r   r   r   r   r   r   r   rQ      s$   


 -49rQ   )@r   loggingstringcollectionsr   urllib.parser   Zdjango.confr   Zdjango.core.exceptionsr   r   Zdjango.httpr   Zdjango.http.requestr	   Zdjango.urlsr
   Zdjango.utils.cacher   Zdjango.utils.cryptor   r   Zdjango.utils.deprecationr   Zdjango.utils.functionalr   Zdjango.utils.httpr   Zdjango.utils.logr   Zdjango.utils.regex_helperr   	getLoggerrg   rI   r   r   r   r   r   r   r   rH   rK   r   rG   ascii_lettersdigitsr   rm   r   r   r0   r2   r:   r;   r<   	Exceptionr=   rL   rO   rP   rQ   r   r   r   r   <module>   sX   
