50 lines
1.2 KiB
Nim
50 lines
1.2 KiB
Nim
import spec/[digest, helpers]
|
|
|
|
type Randao* = object
|
|
seed*: Eth2Digest
|
|
|
|
const MaxRandaoLevels = 10000 # TODO: This number is arbitrary
|
|
|
|
proc initRandao*(seed: Eth2Digest): Randao =
|
|
result.seed = seed
|
|
|
|
proc initRandao*(bytes: openarray[byte]): Randao =
|
|
if bytes.len != sizeof(Eth2Digest):
|
|
raise newException(Exception, "Wrong randao size")
|
|
var s: Eth2Digest
|
|
s.data[0 .. ^1] = bytes
|
|
initRandao(s)
|
|
|
|
proc initialCommitment*(r: Randao): Eth2Digest =
|
|
repeatHash(r.seed, MaxRandaoLevels)
|
|
|
|
proc reveal*(r: Randao, commitment: Eth2Digest): Eth2Digest =
|
|
if commitment == r.seed:
|
|
raise newException(Exception, "Randao: cannot reveal for seed")
|
|
result = r.seed
|
|
for i in 0 .. MaxRandaoLevels:
|
|
let h = eth2hash(result.data)
|
|
if h == commitment:
|
|
return
|
|
result = h
|
|
|
|
raise newException(Exception, "Randao: commitment not found")
|
|
|
|
when isMainModule:
|
|
import times, nimcrypto
|
|
var seed: Eth2Digest
|
|
let r = initRandao(seed)
|
|
|
|
var s = epochTime()
|
|
var ic = r.initialCommitment()
|
|
var e = epochTime()
|
|
echo "initialCommitment: ", ic
|
|
echo "Took time: ", e - s
|
|
s = epochTime()
|
|
let rev = r.reveal(ic)
|
|
e = epochTime()
|
|
echo "reveal: ", rev
|
|
echo "Took time: ", e - s
|
|
|
|
echo r.reveal(eth2hash([1.byte, 2, 3])) # Should raise
|