o "= j_@sdZddlmZddlZddlmZmZddlmZm Z m Z ddl m Z ddl mZmZdd lmZdd lmZmZmZdd lmZmZerLdd lmZeeZd ZdZdZ dde!dDZ"dZ#d4ddZ$d5d d!Z%d6d%d&Z&d7d*d+Z'd8d.d/Z(Gd0d1d1Z)Gd2d3d3Z*dS)9zL Implements the HPACK header compression algorithm as detailed by RFC 7541. ) annotationsN) TYPE_CHECKINGAny)HPACKDecodingErrorInvalidTableSizeErrorOversizedHeaderListError)HuffmanEncoder) REQUEST_CODESREQUEST_CODES_LENGTH)decode_huffman) HeaderTupleHeaderWeaklyTypedNeverIndexedHeaderTuple) HeaderTabletable_entry_size)Iterable@cCsg|]}d|dqS)r).0irrUC:\Users\psant\Downloads\Anu Raj Backend\school\venv\Lib\site-packages\hpack/hpack.py sr iheaderrrawboolreturnr cCs@t|d}t|d}|s||d|dS|||S)zj Provides a header as a unicode string if raw is False, otherwise returns it as a bytestring. rrutf-8N)bytes __class__decode)rrnamevaluerrr_unicode_if_needed#s   r'integerint prefix_bits bytearraycCstd|||dkrd|}t||dks|dkr%d|}t|t|}||kr2t|gS|g}||8}|dkrN||d@d|d L}|dks=||t|S) zi Encodes an integer according to the wacky integer encoding rules defined in the HPACK spec. zEncoding %d with %d bitsrz'Can only encode positive integers, got r)Prefix bits must be between 1 and 8, got N)logdebug ValueError_PREFIX_BIT_MAX_NUMBERSr+append)r(r*msg max_numberelementsrrrencode_integer0s$    r9datar"tuple[int, int]c Cs|dks|dkrd|}t|t|}d}d}dd|?}z.|d|@}||krL ||}|d7}|dkr@||d|>7}n|||>7}qL|d7}q+Wntyc} z d |}t|| d } ~ wwtd ||||fS) z Decodes an integer according to the wacky integer encoding rules defined in the HPACK spec. Returns a tuple of the decoded integer and the number of bytes that were consumed from ``data`` in order to get that integer. rr,r-rTr.r0z3Unable to decode HPACK integer representation from NzDecoded %d, consumed %d bytes)r3r4 IndexErrorrr1r2) r:r*r6r7indexshiftmasknumberZ next_byteerrrrrdecode_integerOs6      rC header_dictdict[bytes | str, bytes | str])Iterable[tuple[bytes | str, bytes | str]]ccsRt|tsdt|}t|t|ddd}|D] }|||fVqdS)z Converts a dictionary to an iterable of key-value tuples. This is a HPACK-specific function because it pulls "special-headers" out first and then emits them. zheader_dict not a dict, but cSst|d S)N:) _to_bytes startswith)krrrsz#_dict_to_iterable..)keyN) isinstancedicttype TypeErrorsortedkeys)rDr6rRrLrrr_dict_to_iterablevs rSr&bytes | str | AnycCs.t|}|tur |S|turt|}|dS)zB Convert anything to bytes through a UTF-8 encoded string r!N)rOr"strencode)r&trrrrHs  rHc@s~eZdZdZd%ddZed&ddZejd'd dZ d(d)ddZd*d+ddZ d,ddZ d*d-ddZ d*d.d d!Z d/d"d#Z d$S)0Encoderzm An HPACK encoder object. This object takes HTTP headers and emits encoded HTTP/2 header blocks. r NonecCst|_ttt|_g|_dSN)r header_tabler r r huffman_codertable_size_changesselfrrr__init__s  zEncoder.__init__r)cC|jjSz> Controls the size of the HPACK header table. Nr[maxsizer^rrrheader_table_sizezEncoder.header_table_sizer&cCs$||j_|jjr|j|dSdSrZ)r[rdresizedr]r5r_r&rrrresTheadersIterable[HeaderTuple | tuple[bytes | str, bytes | str] | tuple[bytes | str, bytes | str, bool | None]] | dict[bytes | str, bytes | str]huffmanrr"c Csg}|jjr||d|j_t|trt|}n t|}|D].}d}t|tr0|j }n t |dkr:|d}t |dt |df}|| |||q"d |}td||S)a Takes a set of headers and encodes them into a HPACK-encoded header block. :param headers: The headers to encode. Must be either an iterable of tuples, an iterable of :class:`HeaderTuple `, or a ``dict``. If an iterable of tuples, the tuples may be either two-tuples or three-tuples. If they are two-tuples, the tuples must be of the format ``(name, value)``. If they are three-tuples, they must be of the format ``(name, value, sensitive)``, where ``sensitive`` is a boolean value indicating whether the header should be added to header tables anywhere. If not present, ``sensitive`` defaults to ``False``. If an iterable of :class:`HeaderTuple `, the tuples must always be two-tuples. Instead of using ``sensitive`` as a third tuple entry, use :class:`NeverIndexedHeaderTuple ` to request that the field never be indexed. .. warning:: HTTP/2 requires that all special headers (headers whose names begin with ``:`` characters) appear at the *start* of the header block. While this method will ensure that happens for ``dict`` subclasses, callers using any other iterable of tuples **must** ensure they place their special headers at the start of the iterable. For efficiency reasons users should prefer to use iterables of two-tuples: fixing the ordering of dictionary headers is an expensive operation that should be avoided if possible. :param huffman: (optional) Whether to Huffman-encode any header sent as a literal value. Except for use when debugging, it is recommended that this be left enabled. :returns: A bytestring containing the HPACK-encoded header block. FrrrzEncoded header block to %sN)r[rgr5_encode_table_size_changerMrNrSiterr Z indexablelenrHaddjoinr1r2) r_rirkZ header_blockZ hpack_headersr sensitiveZ new_headerencodedrrrrVs&8       zEncoder.encodeFto_addtuple[bytes, bytes]rrc Cstd||||\}}|stnt}|j||}|dur0|||||}|s.|j|||S|\} }} | r>|| }|S| | |||}|sO|j|||S)z6 Serializes a header key-value tuple. z7Adding %s to the header table, sensitive:%s, huffman:%sN) r1r2INDEX_INCREMENTAL INDEX_NEVERr[search_encode_literalrp_encode_indexed_encode_indexed_literal) r_rtrrrkr%r&indexbitmatchrsr>Zperfectrrrrps0    z Encoder.addr>cCs"t|d}|ddO<t|S)zD Encodes a header using the indexed representation. r0rr.N)r9r")r_r>fieldrrrrzMs zEncoder._encode_indexedr%r|cCsx|r|j|}|j|}tt|d}tt|d}|r.|ddO<|ddO<d|t||t||gS)z Encodes a header with a literal name and literal value. If ``indexing`` is True, the header will be added to the header table: otherwise it will not. r0rr.rlN)r\rVr9rorqr")r_r%r&r|rkname_len value_lenrrrryUs  zEncoder._encode_literalcCs||tkr t|d}nt|d}|dt|O<|r!|j|}tt|d}|r2|ddO<dt|t||gS)zv Encodes a header with an indexed name and a literal value and performs incremental indexing. rr0r.rlN)rvr9ordr\rVrorqr")r_r>r&r|rkprefixrrrrr{js   zEncoder._encode_indexed_literalcCs@d}|jD]}t|d}|ddO<|t|7}qg|_|S)zd Produces the encoded form of all header table size change context updates. rlr N)r]r9r")r_blockZ size_bytesbrrrrms  z!Encoder._encode_table_size_changeNr rYr r)r&r)r rY)T)rirjrkrr r"F)rtrurrrrkrr r")r>r)r r") r%r"r&r"r|r"rkrr r") r>r)r&r"r|r"rkrr r")r r")__name__ __module__ __qualname____doc__r`propertyresetterrVrprzryr{rmrrrrrXs    m 1  rXc@seZdZdZefd#ddZed$dd Zejd%d d Zd&d'ddZ d(ddZ d)ddZ d*ddZ d*ddZ d*ddZd+d d!Zd"S),Decodera  An HPACK decoder object. .. versionchanged:: 2.3.0 Added ``max_header_list_size`` argument. :param max_header_list_size: The maximum decompressed size we will allow for any single header block. This is a protection against DoS attacks that attempt to force the application to expand a relatively small amount of data into a really large header list, allowing enormous amounts of memory to be allocated. If this amount of data is exceeded, a `OversizedHeaderListError ` exception will be raised. At this point the connection should be shut down, as the HPACK state will no longer be usable. Defaults to 64kB. :type max_header_list_size: ``int`` max_header_list_sizer)r rYcCst|_||_|jj|_dSrZ)rr[rrdmax_allowed_table_size)r_rrrrr`s zDecoder.__init__cCrarbrcr^rrrrerfzDecoder.header_table_sizer&cCs ||j_dSrZrcrhrrrres Fr:r"rrIterable[HeaderTuple]c sntd|t|}g}t|}d}d}||kr||}t|d@} t|d@} t|d@} | r<|||d\} } n/| rJ|||d\} } n!| r`|rTd}t||||d} d} n | ||d\} } | r| | |t | d| d7}||j krd |j d }t ||| 7}||ks|z fd d |DWSty}zd }t||d}~ww)a Takes an HPACK-encoded header block and decodes it into a header set. :param data: A bytestring representing a complete HPACK-encoded header block. :param raw: (optional) Whether to return the headers as tuples of raw byte strings or to decode them as UTF-8 before returning them. The default value is False, which returns tuples of Unicode strings :returns: A list of two-tuples of ``(name, value)`` representing the HPACK-encoded headers, in the order they were decoded. :raises HPACKDecodingError: If an error is encountered while decoding the header block. z Decoding %srr.@rNz/Table size update not at the start of the blockrzA header list larger than z has been receivedcsg|]}t|qSr)r')rhrrrrsz"Decoder.decode..z!Unable to decode headers as UTF-8)r1r2 memoryviewror_decode_indexed_decode_literal_indexr_update_encoding_context_decode_literal_no_indexr5rrr_assert_valid_table_sizeUnicodeDecodeError)r_r:rZdata_memridata_lenZ inflated_sizeZ current_indexcurrentZindexedZ literal_indexZencoding_updaterconsumedr6rBrrrr$s\            4 zDecoder.decodecCs|j|jkr d}t|dS)zs Check that the table size set by the encoder is lower than the maximum we expect to have. z3Encoder did not shrink table size to within the maxN)rerr)r_r6rrrrs z Decoder._assert_valid_table_sizecCs.t|d\}}||jkrd}t|||_|S)zC Handles a byte that updates the encoding context. rz)Encoder exceeded max allowable table sizeN)rCrrre)r_r:Znew_sizerr6rrrr's  z Decoder._update_encoding_contexttuple[HeaderTuple, int]cCs4t|d\}}t|j|}td||||fS)zP Decodes a header represented using the indexed representation. r0zDecoded %s, consumed %dN)rCr r[ get_by_indexr1r2)r_r:r>rrrrrr3szDecoder._decode_indexedcC|j|ddS)NF should_index_decode_literalr_r:rrrr<z Decoder._decode_literal_no_indexcCr)NTrrrrrrr?rzDecoder._decode_literal_indexrcCsvd}|r|dd@}d}d}n|d}|d@}d}t|d@}|r5t||\}} |j|d} | }d} n1|dd }t|d \} } || | | } t| | krVd } t| |dd @r`t| } | | d}|| | d }t|d \} } || | | } t| | krd } t| |dd @rt| } || | 7}|rt| | }nt| | }|r|j | | t d |||||fS)z> Decodes a header represented with a literal. r?rFrrNr0zTruncated header blockr.z/Decoded %s, total consumed %d bytes, indexed %s) rrCr[rrorr rr rpr1r2)r_r:rZtotal_consumedZ indexed_namerZ not_indexableZ high_byter>rr%lengthr6r&rrrrrBsX           zDecoder._decode_literalN)rr)r rYrrr)r:r"rrr rr)r:r"r r))r:r"r r)r:r"rrr r)rrrrDEFAULT_MAX_HEADER_LIST_SIZEr`rrerr$rrrrrrrrrrrs    S r)rrrrr r )r(r)r*r)r r+)r:r"r*r)r r;)rDrEr rF)r&rTr r")+r __future__rloggingtypingrr exceptionsrrrrkr Zhuffman_constantsr r Z huffman_tabler structr rrtablerrcollections.abcr getLoggerrr1Z INDEX_NONErwrvranger4rr'r9rCrSrHrXrrrrrs4        '  z