mò Kã¸Ec@sÄdZdkZdkZdkZdkZdkZdklZlZdk l Z dk l Z dd„Z d„Zdefd „ƒYZd „Zd e fd „ƒYZd efd„ƒYZdS(s-Digest authentication for ZEO This authentication mechanism follows the design of HTTP digest authentication (RFC 2069). It is a simple challenge-response protocol that does not send passwords in the clear, but does not offer strong security. The RFC discusses many of the limitations of this kind of protocol. Guard the password database as if it contained plaintext passwords. It stores the hash of a username and password. This does not expose the plaintext password, but it is sensitive nonetheless. An attacker with the hash can impersonate the real user. This is a limitation of the simple digest scheme. HTTP is a stateless protocol, and ZEO is a stateful protocol. The security requirements are quite different as a result. The HTTP protocol uses a nonce as a challenge. The ZEO protocol requires a separate session key that is used for message authentication. We generate a second nonce for this purpose; the hash of nonce and user/realm/password is used as the session key. TODO: I'm not sure if this is a sound approach; SRP would be preferred. N(sDatabasesClient(s ZEOStorage(s AuthErroricCsˆtiidƒo)tdƒ}|i|ƒ}|iƒnIg}t |ƒD]}|t t iddƒƒqM~}di|ƒ}|S(Ns /dev/urandomiiÿt(tostpathtexiststopentftreadtntstcloset_[1]trangetitchrtrandomtrandinttLtjoin(RRR RR R((t3/data/zmath/zope/lib/python/ZEO/auth/auth_digest.pytget_random_bytes0s 9cCsti|ƒiƒS(N(tshatnewRt hexdigest(R((RR:stDigestDatabasecBstZdd„Zd„ZRS(NcCs&ti|||ƒtdƒ|_dS(Ni(tDatabaset__init__tselftfilenametrealmRtnoncekey(RRR((RR>scCs-td||i|fƒ}||i|RDR@R&R?RA((Rt auth_responseks  (R#R$R.R4R9R=RGt extensions(((RR*Qs     t DigestClientcBstZddgZd„ZRS(NR=RGc Cs©|iiƒ\} }}| |jotd| |fƒ‚ntd|||fƒ}td||fƒ}|ii |||fƒ}|ot||ƒSndSdS(Nsexpected realm %r, got realm %rs%s:%s:%ss%s:%s(RtstubR=t_realmR@R'Rt AuthErrorRRRR&tresp_digRGtresultR)R%( RRRRR'RMR&RNR@RK((Rtstartƒs (R#R$RHRO(((RRI€s (t__doc__RRRR2R0t ZEO.auth.baseRtClienttZEO.StorageServert ZEOStoragetZEO.ExceptionsRLRRRR)R*RI(RLR2RRRRIRRTRRRR*R0RR)R((Rt?$s         /