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zcash-test-vectors
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orchard_sinsemilla.py: corrections, and add test vector for SinsemillaHash. 

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This commit is contained in:
Daira Hopwood 2021-04-02 17:57:29 +01:00
parent 9184c78c0f
commit 28370d5fe9
1 changed files with 17 additions and 7 deletions
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24
orchard_sinsemilla.py
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@ -6,7 +6,7 @@ import math
import orchard_iso_pallas
from pyblake2 import blake2b, blake2s
from orchard_pallas import Fp, p, q, PALLAS_B
from orchard_pallas import Fp, p, q, PALLAS_B, Point
from orchard_iso_pallas import PALLAS_ISO_B, PALLAS_ISO_A
from sapling_utils import i2beosp, cldiv, beos2ip, i2leosp, lebs2ip
from binascii import hexlify
@ -139,25 +139,28 @@ SINSEMILLA_K = 10
def pad(n, m):
padding_needed = n * SINSEMILLA_K - m.len
zeros = BitArray('0b' + ('0' * padding_needed))
zeros = BitArray(bin='0' * padding_needed)
m = m + zeros
pieces = []
for i in range(0, n):
for i in range(n):
pieces.append(
lebs2ip(m[i*SINSEMILLA_K:i*(SINSEMILLA_K + 1)])
lebs2ip(m[i*SINSEMILLA_K : (i+1)*SINSEMILLA_K])
)
return pieces
def sinsemilla_hash_to_point(d, m):
assert isinstance(m, BitArray)
n = cldiv(m.len, SINSEMILLA_K)
m = pad(n, m)
acc = group_hash(b"z.cash:SinsemillaQ", d)
#print("acc", acc)
for m_i in m:
acc = acc + group_hash(b"z.cash:SinsemillaS", i2leosp(32, m_i)) + acc
#print("acc", acc)
return acc
def sinsemilla_hash(d, m):
@ -168,5 +171,12 @@ def sinsemilla_hash_bytes(d, m_bytes):
return sinsemilla_hash(d, BitArray(m_bytes))
if __name__ == "__main__":
sh = sinsemilla_hash_bytes(b"z.cash:test", b"Trans rights now!")
print(sh)
# This is the Pallas test vector from the Sage and Rust code (in affine coordinates).
gh = group_hash(b"z.cash:test", b"Trans rights now!")
assert gh == Point(Fp(10899331951394555178876036573383466686793225972744812919361819919497009261523),
Fp(851679174277466283220362715537906858808436854303373129825287392516025427980))
# 40 bits, so no padding
sh = sinsemilla_hash_to_point(b"z.cash:test-Sinsemilla", BitArray(bin='0001011010100110001101100011011011110110'))
assert sh == Point(Fp(19681977528872088480295086998934490146368213853811658798708435106473481753752),
Fp(14670850419772526047574141291705097968771694788047376346841674072293161339903))