On Wed, Sep 21, 2011 at 2:29 AM, Vincent Hanquez
Hi Felipe,
it's good to see more Skein stuff. it's a great crypto hash and one of the few remaining candidate for SHA-3.
Have you seen the cryptohash package http://hackage.haskell.org/package/cryptohash ?
I always wanted to expose more skein operations specially the hmac function, but never came around to, and maybe it would be good to merge to avoid duplicating efforts ?
I'm aware of cryptohash. I just went through the lazy route of binding to the C library instead of implementing those UBI details =). It would be nice to merge and have everything on cryptohash though. And I guess that cryptohash may become faster than skein because the C library has some implementation details that are unneeded (e.g. it has a buffer, but hash/hash' are kind enough to only give full buffers to the libraries). Also, it seems that cryptohash's Skein is currently broken. The skein package comes with the "golden" KATs sent by the Skein team to the NIST, and passes everything. OTOH, cryptohash's Skein256/Skein512 do not agree with skein's Skein_256_256/Skein_512_512. I've attached a test suite that quickchecks if both implementations give the same answer. My hunch is that you are using the wrong constants, because the first test case (the empty string) already fails: 1) cryptohash and skein have the same implementation of Skein-256-256 FAILED *** Failed! skein: bc 27 63 f7 07 e2 62 b8 0e 03 13 79 15 43 a7 ab 0a 4b 6c d0 83 27 0a fb 2f ce 42 72 e1 bb 0a a9 cryptohash: 0b 04 10 3b 82 8c dd ae bc f5 92 ac 84 5e ca fd 58 87 f6 12 30 a7 55 40 6d 38 d8 53 76 e1 ae 08 (after 1 test): (none) 2) cryptohash and skein have the same implementation of Skein-512-512 FAILED *** Failed! skein: d3 f7 26 3a 09 83 7f 4c e5 c8 ef 70 a5 dd ff ac 7b 92 d6 c2 ac e5 a1 22 65 bd 5b 59 32 60 a3 ff 20 d8 b4 b4 c5 49 4e 94 54 48 b3 7a bb 1f c5 26 f6 b4 60 89 20 8f de 93 8d 7f 23 72 4c 4b df b7 cryptohash: 5a f6 8a 49 12 e0 a6 18 7a 00 49 47 a9 d2 a3 7d 7a 1f 08 73 f0 bd d9 dc 64 83 8e ce 60 da 55 35 c2 a5 5d 03 9b d5 8e 17 89 48 99 6b 7a 83 36 48 6e d9 69 c8 94 be 65 8e 47 d5 95 a5 a9 b8 6a 8b (after 1 test): (none) Cheers, =D -- Felipe.