o DhX@sdZddlZddlmZmZddlmZmZddlm Z m Z m Z ddl m Z ddlmZmZdd lmZdd lmZmZeeZd Zd Zd ZddedDZzeZWn eyae e!fZYnwdZ"ddZ#ddZ$ddZ%ddZ&ddZ'Gddde(Z)Gddde(Z*dS) ze hpack/hpack ~~~~~~~~~~~ Implements the HPACK header compression algorithm as detailed by the IETF. N) HeaderTabletable_entry_size)to_byteto_bytes)HPACKDecodingErrorOversizedHeaderListErrorInvalidTableSizeError)HuffmanEncoder) REQUEST_CODESREQUEST_CODES_LENGTH)decode_huffman) HeaderTupleNeverIndexedHeaderTuple@cCsg|]}d|dqS)r).0irrF/var/www/html/env_mimamsha/lib/python3.10/site-packages/hpack/hpack.py sr icCs<t|d}t|d}|s|d}|d}|||S)zj Provides a header as a unicode string if raw is False, otherwise returns it as a bytestring. rrutf-8)rdecode __class__)headerrawnamevaluerrr_unicode_if_needed,s     r!cCstd|||dkrtd||dks|dkrtd|t|}||kr,t|gS|g}||8}|dkrH||d@d|d L}|dks7||t|S) zn This encodes an integer according to the wacky integer encoding rules defined in the HPACK spec. zEncoding %d with %d bitsrz)Can only encode positive integers, got %sr+Prefix bits must be between 1 and 8, got %s)logdebug ValueError_PREFIX_BIT_MAX_NUMBERS bytearrayappend)integer prefix_bits max_numberelementsrrrencode_integer9s(  r1cCs|dks|dkrtd|t|}d}d}dd|?}z2t|d|@}||krM t||}|d7}|dkrA||d|>7}n|||>7}n|d7}q*Wn ty[td |wtd ||||fS) z This decodes an integer according to the wacky integer encoding rules defined in the HPACK spec. Returns a tuple of the decoded integer and the number of bytes that were consumed from ``data`` in order to get that integer. rr"r#rTr$r&z5Unable to decode HPACK integer representation from %rzDecoded %d, consumed %d bytes)r)r*r IndexErrorrr'r()datar.r/indexshiftmasknumber next_byterrrdecode_integer[s8    r:ccs@t|tsJt|ddd}|D] }|||fVqdS)z This converts a dictionary to an iterable of two-tuples. This is a HPACK-specific function becuase it pulls "special-headers" out first and then emits them. cSst|d S)N:) _to_bytes startswith)krrrsz#_dict_to_iterable..)keyN) isinstancedictsortedkeys) header_dictrDr@rrr_dict_to_iterablesrFcCs*t|ts t|}t|tr|S|dS)z" Convert string to bytes. r)rA basestringstrbytesencode)stringrrrr<s r<c@sjeZdZdZddZeddZejddZddd Zdd d Z d dZ dddZ dddZ ddZ dS)Encoderzm An HPACK encoder object. This object takes HTTP headers and emits encoded HTTP/2 header blocks. cCst|_ttt|_g|_dSN)r header_tabler r r huffman_codertable_size_changesselfrrr__init__s  zEncoder.__init__cC|jjSz> Controls the size of the HPACK header table. rNmaxsizerQrrrheader_table_sizezEncoder.header_table_sizecCs$||j_|jjr|j|dSdSrM)rNrWresizedrPr,rRr rrrrXsTcCstd|g}t|trt|}|jjr ||d|j_|D].}d}t|t r0|j }n t |dkr:|d}t |dt |df}|| |||q"d|}td||S)a Takes a set of headers and encodes them into a HPACK-encoded header block. :param headers: The headers to encode. Must be either an iterable of tuples, an iterable of :class:`HeaderTuple `, or a ``dict``. If an iterable of tuples, the tuples may be either two-tuples or three-tuples. If they are two-tuples, the tuples must be of the format ``(name, value)``. If they are three-tuples, they must be of the format ``(name, value, sensitive)``, where ``sensitive`` is a boolean value indicating whether the header should be added to header tables anywhere. If not present, ``sensitive`` defaults to ``False``. If an iterable of :class:`HeaderTuple `, the tuples must always be two-tuples. Instead of using ``sensitive`` as a third tuple entry, use :class:`NeverIndexedHeaderTuple ` to request that the field never be indexed. .. warning:: HTTP/2 requires that all special headers (headers whose names begin with ``:`` characters) appear at the *start* of the header block. While this method will ensure that happens for ``dict`` subclasses, callers using any other iterable of tuples **must** ensure they place their special headers at the start of the iterable. For efficiency reasons users should prefer to use iterables of two-tuples: fixing the ordering of dictionary headers is an expensive operation that should be avoided if possible. :param huffman: (optional) Whether to Huffman-encode any header sent as a literal value. Except for use when debugging, it is recommended that this be left enabled. :returns: A bytestring containing the HPACK-encoded header block. zHPACK encoding %sFrrrzEncoded header block to %s)r'r(rArBrFrNrZr,_encode_table_size_changer indexablelenr<addjoin)rRheadershuffman header_blockr sensitiverrrrJs$ 2      zEncoder.encodeFc Cstd||\}}|stnt}|j||}|dur.|||||}|s,|j|||S|\} }} | r<|| }|S| | |||}|sM|j|||S)zQ This function takes a header key-value tuple and serializes it. zAdding %s to the header tableN) r'r(INDEX_INCREMENTAL INDEX_NEVERrNsearch_encode_literalr`_encode_indexed_encode_indexed_literal) rRto_addrercrr indexbitmatchencodedr5perfectrrrr` s&     z Encoder.addcCs"t|d}|ddO<t|S)zD Encodes a header using the indexed representation. r&rr$)r1rI)rRr5fieldrrrrj5s zEncoder._encode_indexedcCsx|r|j|}|j|}tt|d}tt|d}|r.|ddO<|ddO<d|t||t||gS)z Encodes a header with a literal name and literal value. If ``indexing`` is True, the header will be added to the header table: otherwise it will not. r&rr$r\)rOrJr1r_rarI)rRrr rmrcname_len value_lenrrrri=s  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. rr&r$r\)rfr1ordrOrJr_rarI)rRr5r rmrcprefixrsrrrrkRs   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. r\r )rPr1rI)rRblock size_bytesrrrr]hs  z!Encoder._encode_table_size_changeN)TF)__name__ __module__ __qualname____doc__rSpropertyrXsetterrJr`rjrirkr]rrrrrLs    R,   rLc@speZdZdZefddZeddZejddZddd Z d d Z d d Z ddZ ddZ ddZddZdS)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 useable. Defaults to 64kB. :type max_header_list_size: ``int`` cCst|_||_|jj|_dSrM)rrNmax_header_list_sizerWmax_allowed_table_size)rRrrrrrSs zDecoder.__init__cCrTrUrVrQrrrrXrYzDecoder.header_table_sizecCs ||j_dSrMrVr[rrrrXs FcsXtd|t|}g}t|}d}d}||krt||}|d@r$dnd} |d@r,dnd} |d@r4dnd} | rD|||d\} } n-| rR|||d\} } n| rf|rZtd |||d} d} n | ||d\} } | r| | |t | 7}||j krt d |j || 7}||ks|z fd d |DWStytd w)a Takes an HPACK-encoded header block and decodes it into a header set. :param data: A bytestring representing a complete HPACK-encoded header block. :param raw: (optional) Whether to return the headers as tuples of raw byte strings or to decode them as UTF-8 before returning them. The default value is False, which returns tuples of Unicode strings :returns: A list of two-tuples of ``(name, value)`` representing the HPACK-encoded headers, in the order they were decoded. :raises HPACKDecodingError: If an error is encountered while decoding the header block. z Decoding %srr$TF@ryNz/Table size update not at the start of the blockz.A header list larger than %d has been receivedcsg|]}t|qSr)r!)rhrrrrsz"Decoder.decode..z"Unable to decode headers as UTF-8.)r'r( memoryviewr_r_decode_indexed_decode_literal_indexr_update_encoding_context_decode_literal_no_indexr,rrr_assert_valid_table_sizeUnicodeDecodeError)rRr4rdata_memrbdata_len inflated_size current_indexcurrentindexed literal_indexencoding_updaterconsumedrrrrs`           7 zDecoder.decodecCs|j|jkr tddS)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)rXrr rQrrrrs z Decoder._assert_valid_table_sizecCs*t|d\}}||jkrtd||_|S)zC Handles a byte that updates the encoding context. rxz)Encoder exceeded max allowable table size)r:rr rX)rRr4new_sizerrrrrs z Decoder._update_encoding_contextcCs4t|d\}}t|j|}td||||fS)zP Decodes a header represented using the indexed representation. r&zDecoded %s, consumed %d)r:rrN get_by_indexr'r()rRr4r5rrrrrrszDecoder._decode_indexedcC ||dS)NF_decode_literalrRr4rrrr' z Decoder._decode_literal_no_indexcCr)NTrrrrrr*rzDecoder._decode_literal_indexcCszd}|rt|dd@}d}d}nt|d}|d@}d}|d@}|r7t||\}} |j|d} | }d} n1|dd }t|d \} } || | | } t| | krVtd t|dd @rbt| } | | d}|| | d }t|d \} } || | | } t| | krtd t|dd @rt| } || | 7}|rt| | } nt| | } |r|j | | t d | ||| |fS)z> Decodes a header represented with a literal. r?ruFrtrNr&zTruncated header blockr$z/Decoded %s, total consumed %d bytes, indexed %s) rr:rNrr_rr rrr`r'r()rRr4 should_indextotal_consumed indexed_namerr not_indexable high_byter5rrlengthr rrrrr-sT        zDecoder._decode_literalNr|)r}r~rrDEFAULT_MAX_HEADER_LIST_SIZErSrrXrrrrrrrrrrrrrvs    U    r)+rloggingtablerrcompatrr exceptionsrrr rcr huffman_constantsr r huffman_tabler structrr getLoggerr}r' INDEX_NONErgrfranger*rG NameErrorrHrIrr!r1r:rFr<objectrLrrrrrs8      ") Z