2.0.0: FIPS 202 SHA-3 standard hash algorithms and SHAVS test vectors

[skull-squadron]

Closes #14

[skull-squadron]

Ready to merge and release.

cc: @FooBarWidget

[skull-squadron]

TL;DR Keccak reference implementation -> FIPS 202 patch

--- KeccakSponge.c.orig 2016-03-21 00:20:19.000000000 -0700
+++ KeccakSponge.c  2016-03-20 11:07:20.000000000 -0700
@@ -200,13 +200,13 @@
 {
     // Note: the bits are numbered from 0=LSB to 7=MSB
     if (state->bitsInQueue + 1 == state->rate) {
-        state->dataQueue[state->bitsInQueue/8 ] |= 1 << (state->bitsInQueue % 8);
+        state->dataQueue[state->bitsInQueue/8 ] |= 6 << (state->bitsInQueue % 8);
         AbsorbQueue(state);
         memset(state->dataQueue, 0, state->rate/8);
     }
     else {
         memset(state->dataQueue + (state->bitsInQueue+7)/8, 0, state->rate/8 - (state->bitsInQueue+7)/8);
-        state->dataQueue[state->bitsInQueue/8 ] |= 1 << (state->bitsInQueue % 8);
+        state->dataQueue[state->bitsInQueue/8 ] |= 6 << (state->bitsInQueue % 8);
     }
     state->dataQueue[(state->rate-1)/8] |= 1 << ((state->rate-1) % 8);
     AbsorbQueue(state);

There are simpler, shorter implementations out there as well.

References

• Keccak Round 3 finalist submission (zip) from SHA-3 Competition, Round 3
• FIPS 202 Standard (pdf)
  from FIPS 202 Standard (landing)
• SHAVS test vectors for byte-length messages (zip)
  from SHAVS test vectors (landing)

[canterberry]

Sorry for the very long delay on this PR.

I completely agree with #14 that this library is a bit of a misnomer. There are consumers downstream, however, that are using it intentionally to provide the Keccak variant. Even with a major version bump, if the library suddenly begins to produce a different hash, it could cause some trouble. To that end, I propose an iterative approach vs a rewrite.

Since the discussion on #14 is dated and closed, I'll create some follow-up issues to try and establish a plan for how to move forward, and we'll make this happen!

[canterberry]

Created #36 as a follow-up for a phased rollout of SHA-3.