ó BwLc@s~dZddlTddlZddlmZmZmZddlmZddl m Z ddl Z de fd„ƒYZ dS( s$Id$iĸĸĸĸ(t*N(t ceil_shiftt exact_log2t exact_div(tCounter(tAESt AESGeneratorcBsgeZdZejZdZd ZdedZd„Zd„Z d„Z d „Z d „Z d „Z RS( s)The Fortuna "generator" This is used internally by the Fortuna PRNG to generate arbitrary amounts of pseudorandom data from a smaller amount of seed data. The output is generated by running AES-256 in counter mode and re-keying after every mebibyte (2**16 blocks) of output. i iiticCs­tjd|jddddtƒ|_d|_t|jƒ|_d|j>|jks_t ‚t |j |jƒ|_ |j |j |jks–t ‚|j |j|_dS(Ntnbitsit initial_valueit little_endiani(Rtnewt block_sizetTruetcountertNonetkeyRtblock_size_shifttAssertionErrorRtkey_sizetblocks_per_keytmax_blocks_per_requesttmax_bytes_per_request(tself((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pyt__init__>s( cCsq|jdkr"d|j|_n|jtj|j|ƒjƒƒ|jƒt|jƒ|jksmt ‚dS(NR( RRRt_set_keytSHAd256R tdigestRtlenR(Rtseed((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pytreseedKs # cCs||dkst‚|d?}|d@}g}x*t|ƒD]}|j|jdƒƒq9W|j|j|ƒƒdj|ƒS(Niiitiiĸĸi(Rtxrangetappendt_pseudo_random_datatjoin(Rtbytestnum_full_blockst remaindertretvalti((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pytpseudo_random_dataRs  cCs.||_tj|tjd|jƒ|_dS(NR(RRR tMODE_CTRRt_cipher(RR((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pyR_s cCsĶd|ko|jkns.tdƒ‚nt||jƒ}|j|ƒ| }|j|j|jƒƒt|ƒ|ks„t‚t|jƒ|j ksĒt‚|S(Nis6You cannot ask for more than 1 MiB of data per request( RRRRt_generate_blocksRRRRR(RR$t num_blocksR'((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pyR"cscCsū|jdkrtdƒ‚nd|ko8|jknsCt‚g}x4t|d?ƒD]"}|j|jj|jƒƒqZW|d@|j >}|j|jj|j| ƒƒdj |ƒS(Ns#generator must be seeded before useii iĸR( RRRRR R!R+tencryptt_four_kiblocks_of_zerosRR#(RR-R'R(tremaining_bytes((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pyR,us%  i(t__name__t __module__t__doc__RR RRR/RRR)RR"R,(((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pyR%s     (t __revision__tCrypto.Util.python_compattstructtCrypto.Util.numberRRRt Crypto.UtilRt Crypto.CipherRRtobjectR(((sJ/usr/lib/python2.7/dist-packages/Crypto/Random/Fortuna/FortunaGenerator.pyts