j#dZddlmZmZmZmZddlZddlmZm Z m Z ddl m Z m Z ejdkZdZd Zd Zdd Zd ZddZdZdS)z Functions for parsing and dumping using the ASN.1 DER encoding. Exports the following items: - emit() - parse() - peek() Other type classes are defined that help compose the types listed above. )unicode_literalsdivisionabsolute_importprint_functionN)byte_clschr_cls type_name)int_from_bytes int_to_bytes)z2 fc " "Q;i>O>OOPPP zzVaZZENOOO fc " "Q;i>O>OOPPP zzVaZZ86ABBB c3  K89S>>IJJJ Qww@3FGGG h ) )X@9XCVCVVWWW X 6 6 AAFct|tstdt|zt |}t ||\}}|r||krt d||z z|S)al Parses a byte string of ASN.1 BER/DER-encoded data. This is typically not useful. Instead, use one of the standard classes from asn1crypto.core, or construct a new class with specific fields, and call the .load() class method. :param contents: A byte string of BER/DER-encoded data :param strict: A boolean indicating if trailing data should be forbidden - if so, a ValueError will be raised when trailing data exists :raises: ValueError - when the contents do not contain an ASN.1 header or are truncated in some way TypeError - when contents is not a byte string :return: A 6-element tuple: - 0: integer class (0 to 3) - 1: integer method - 2: integer tag - 3: byte string header - 4: byte string content - 5: byte string trailer rz4Extra data - %d bytes of trailing data were provided)rrrr len_parser)rstrict contents_leninfoconsumeds rparser$Ks: h ) )X@9XCVCVVWWWx==LHl33ND( m(l**OS_bjSjklll Krct|tstdt|zt |t |\}}|S)aW Parses a byte string of ASN.1 BER/DER-encoded data to find the length This is typically used to look into an encoded value to see how long the next chunk of ASN.1-encoded data is. Primarily it is useful when a value is a concatenation of multiple values. :param contents: A byte string of BER/DER-encoded data :raises: ValueError - when the contents do not contain an ASN.1 header or are truncated in some way TypeError - when contents is not a byte string :return: An integer with the number of bytes occupied by the ASN.1 value r)rrrr rr)rr"r#s rpeekr&rsQ& h ) )X@9XCVCVVWWWHc(mm44ND( Orc |tkrtd|}||dzkrttd||z fztrt ||n||}|dz }|dz}|dz dz}|dkrd} ||dzkrttd||z fztrt ||n||} |dz }| dkr|dkrtd|dz}|| d zz }| d z dkrn|dkrtd||dzkrttd||z fztrt ||n||} |dz }d } | d z dkr || d zz} n| d z} | rJ||| zkrtt| ||z fz|| z }|t ||| z |d z} nh|std|} || dzks|| | dzdkr4t ||| d|dz\}} || dzk#|| | dzdk4| dz } d} | |krtt| |z ||z fz|r|| fS|dz |||||||| t| z | f| fS)a Parses a byte string into component parts :param encoded_data: A byte string that contains BER-encoded data :param data_len: The integer length of the encoded data :param pointer: The index in the byte string to parse from :param lengths_only: A boolean to cause the call to return a 2-element tuple of the integer number of bytes in the header and the integer number of bytes in the contents. Internal use only. :param depth: The recursion depth when evaluating indefinite-length encoding. :return: A 2-element tuple: - 0: A tuple of (class_, method, tag, header, content, trailer) - 1: An integer indicating how many bytes were consumed z*Indefinite-length recursion limit exceededrrTzNon-minimal tag encodingrF)signedz-Indefinite-length element must be constructeds) lengths_onlydepth) _MAX_DEPTHr_INSUFFICIENT_DATA_MESSAGE_PY2ordr rr) encoded_datadata_lenpointerr/r0start first_octetr constructednum length_octettrailer contents_end length_octets_s rrrs6 zEFFF E'A+3q(W:L6MMNNN04O#l7+,,,,w:OK qLG  C!#q(K byy 'A+%% !;q(WBT>U!UVVV04O#l7+,,,,w:OC qLGd{{saxx !;<<< 3JC 39 Cax1}}  88788 8'A+3q(W:L6MMNNN15P3|G,---<;PL qLGGqA,"45 %s*  "'M111 !;}hY`N`>a!abbb } $G"^L=AXY`A`4ajo%p%p%ppLL R !PQQQ"L\A---l>Y1Z^i1i1i"(x\`hmnoho"p"p"p<\A---l>Y1Z^i1i1i A L!Gh3|g7MxZaOa6bbccc'&& 1    w ' c'll!:: ;      rcd}d}||dzz}||dzz}|dkrEd}|dkr't||dzz|z}|sd}|dz }|dk't|dz|z}n|t||zz }t|}|dkr|t|z }n6t|}|tdt|zz }||z }|S) a Constructs the header bytes for an ASN.1 object :param class_: An integer ASN.1 class value: 0 (universal), 1 (application), 2 (context), 3 (private) :param method: An integer ASN.1 method value: 0 (primitive), 1 (constructed) :param tag: An integer ASN.1 tag value :param contents: A byte string of the encoded byte contents :return: A byte string of the ASN.1 DER header rrr1r)r(r+r*r,)r rr ) rrrrheaderid_numcont_bitlength length_bytess rrrs*F F fkF fkF byyAggXt455>F (C Agg "%%.'&3,''' ]]F }}'&//!#F++ '$\!2!22333, Mr)F)rFr)__doc__ __future__rrrrsys_typesrr r utilr r version_infor4r3r2rr$r&rrrrrOs  SRRRRRRRRRRR 0000000000........ 4[  .B.B.Bb$$$$N4ggggT.....r