h1dZddlZddlmZddlmZmZddlmZm Z m Z ddl m Z  ddlm Z n#e$r ddlm Z YnwxYwd Z dd ed e d dede dede dedefdZdeded e d dedef dZd ed e d dedefdZd ede dede deeeff dZd ed e d dede dede dedeeeffdZdeeefdedefdZdS)z,Anything related to encryption / decryption.N)md5)TupleUnion)b_ord_str_)ByteStringObject)Literals (N^NuAdNV..h>/ dSizTpasswordrev) key_length owner_entryp_entry id1_entrymetadata_encryptreturncFtt|ttzdd}t|}||jt jd|} || ||j|dkr|s|d|} |dkr;tdD]+} t| d|} ,| d|S)a Implementation of algorithm 3.2 of the PDF standard security handler. See section 3.5.2 of the PDF 1.6 reference. Args: password: The encryption secret as a bytes-string rev: The encryption revision (see PDF standard) key_length: owner_entry: p_entry: A set of flags specifying which operations shall be permitted when the document is opened with user access. If bit 2 is set to 1, all other bits are ignored and all operations are permitted. If bit 2 is set to 0, permission for operations are based on the values of the remaining flags defined in Table 24. id1_entry: metadata_encrypt: (Default value = True) Returns: An MD5 hash of key_length characters. N zz_alg33..s6JJ(c$x..1"455JJJJJJr()_alg33_1rr r RC4_encryptr join) r)r*r rkeyuser_password_bytesvalnew_keyr2s @r&_alg33r;|s" >3 3 3Cmd3F.G.GG"MNN c. / /C axxq" , ,AggJJJJcJJJJJGgs++CC Jr(c*t|ttzdd}t|}|}|dkr3t dD]#}t|}$|d|}|S)z Steps 1-4 of algorithm 3.3. Args: password: rev: The encryption revision (see PDF standard) key_length: Returns: A transformed version of the password Nrrr)rr rrrr )r r rr!r"r$r%r7s r&r4r4sD)<$=$==ssCDDN NAxxzzH axxr . .A8}}++--HH ;J; C Jr(cdd}d}t||||||}t|t}||fS)af Implementation of algorithm 3.4 of the PDF standard security handler. See section 3.5.2 of the PDF 1.6 reference. Args: password: owner_entry: p_entry: A set of flags specifying which operations shall be permitted when the document is opened with user access. If bit 2 is set to 1, all other bits are ignored and all operations are permitted. If bit 2 is set to 0, permission for operations are based on the values of the remaining flags defined in Table 24. id1_entry: Returns: A Tuple (u-value, key) r)r'r5r)r rrrr rr7Us r&_alg34r@sB4CJ 3 K) L LC C,--A c6Mr(c t||||||}t}|t||j|} t || } tddD]H} d} |D]1} | ttt| | z z } 2t | | } I| dz|fS)a Implementation of algorithm 3.4 of the PDF standard security handler. See section 3.5.2 of the PDF 1.6 reference. Args: password: rev: The encryption revision (see PDF standard) key_length: owner_entry: p_entry: A set of flags specifying which operations shall be permitted when the document is opened with user access. If bit 2 is set to 1, all other bits are ignored and all operations are permitted. If bit 2 is set to 0, permission for operations are based on the values of the remaining flags defined in Table 24. id1_entry: metadata_encrypt: A boolean Returns: A tuple (value, key) rr,r(s) r'rrrrrr5r rr/r)r r rrrrrr7r"r$r9r2r:ks r&_alg35rCs@ 3 K) L LC AHH !!! HHY %&&&xxzzH c8 $ $C1b\\(( , ,A r#d1ggk**++ +GG'3'' ,  $$r(r7 plaintextc Fttd}d}tdD]M}|||zt||t|zzdz}||||c||<||<Nd\}}g}|D]}|dzdz}|||zdz}||||c||<||<|||||zdz}|t t t||z d|S)Nr)rrrr()listr rlenappendrr/r6)r7rDSjr2retvalplaintext_charts r&r5r5,s0 U3ZZA A 3ZZ   1XSSXX.// /3 6qT1Q4 !add DAq F#99 UcM 1X qT1Q4 !ad qtad{c! " bT.11A566778888 88F  r()T)__doc__rhashlibrtypingrr_utilsrrr genericr r ImportErrortyping_extensionsrstrintboolbytesr'r;r4r@rCr5r(r&r[s<32 """"""""""%%%%%%*****)))))))* "C!C!C!  C!C!" C!  C!  C!C! C!C!C!C!L$$(+$29'2B$PS$ $$$$Ns!1suB##!## #  5%< ####L?%?%  ?%?%" ?%  ?%  ?%?% 5%<?%?%?%?%DU3:&5Us - ;;