261 lines
7.4 KiB
Python
Executable File
261 lines
7.4 KiB
Python
Executable File
#!/usr/bin/env python3
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import sys
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import binascii
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import ed25519raw
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import pyblake2
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def hex(by):
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return str(binascii.hexlify(by), 'ascii')
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def combine_keys(pks):
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combine = None
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for pk in pks:
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P = ed25519raw.decodepoint(pk)
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if not combine:
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combine = P
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else:
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combine = ed25519raw.edwards(combine, P)
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return ed25519raw.encodepoint(combine)
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def combine_sig(R, sigs):
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s = 0
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for si in sigs:
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s += ed25519raw.decodeint(si)
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s = s % ed25519raw.l
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sig = R + ed25519raw.encodeint(s)
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return sig
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def binom(n, k):
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b = 1
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for i in range(1, k + 1):
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b = b * (n - k + i) // i
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return b
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def compute_mask(combination, m, n):
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result = 0
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signer = 0
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while m > 0:
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m = m - 1
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n = n - 1
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numst = binom(n, m)
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while combination >= numst:
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combination -= numst
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signer = signer + 1
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n = n - 1
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numst = binom(n, m)
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result |= 1 << signer
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signer = signer + 1
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return result
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def createPubkey():
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print('Enter randomness: ', end='')
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seckey = ed25519raw.H(input().encode('utf-8'))[0:32]
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pubkey = ed25519raw.publickey(seckey)
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print('Secret Key: %s' % hex(seckey))
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print('Public Key: %s' % hex(pubkey))
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def combinePubkeys(m, n):
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if binom(n, m) > 100:
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raise Exception("Too many keys")
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pks = []
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for i in range(0, n):
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print('Enter pubkey %d: ' % i, end='')
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pk = binascii.unhexlify(input())
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# remove 00 prefix if present
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if len(pk) == 33:
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pk = pk[1:]
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pks.append(ed25519raw.decodepoint(pk))
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for i in range(0, binom(n, m)):
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mask = compute_mask(i, m, n)
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sum = None
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for j in range(0, n):
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if mask & (1 << j) != 0:
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if sum == None:
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sum = pks[j]
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else:
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sum = ed25519raw.edwards(sum, pks[j])
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pk = ed25519raw.encodepoint(sum)
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print('Key %02x: %s' % (mask, hex(pk)))
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def get_nonce(sk, data, ctr):
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h = ed25519raw.H(sk)
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b = ed25519raw.b
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a = 2**(b - 2) + sum(2**i * ed25519raw.bit(h, i) for i in range(3, b - 2))
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r = ed25519raw.Hint(bytes([h[i] for i in range(b >> 3, b >> 2)]) + data +
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binascii.unhexlify("%08x" % ctr))
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R = ed25519raw.scalarmult(ed25519raw.B, r)
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return (r, ed25519raw.encodepoint(R))
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def phase1(data):
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digest = pyblake2.blake2s(data).digest()
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print('Digest: %s' % hex(digest))
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print('Enter counter (small integer): ', end='')
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ctr = int(input())
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print('Enter privkey: ', end='')
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seckey = binascii.unhexlify(input())
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(_, R) = get_nonce(seckey, digest, ctr)
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print('Local commit: %s' % hex(R))
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def combinePhase1(m):
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commits = []
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for i in range(0, m):
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print('Enter commit %d: ' % i, end='')
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commits.append(binascii.unhexlify(input()))
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print('Global commit: %s' % hex(combine_keys(commits)))
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def phase2(data):
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digest = pyblake2.blake2s(data).digest()
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print('Digest: %s' % hex(digest))
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print('Enter combined commitment: ', end='')
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R = binascii.unhexlify(input())
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print('Enter combined public key: ', end='')
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pk = binascii.unhexlify(input())
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print('Enter counter: ', end='')
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ctr = int(input())
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print('Enter privkey: ', end='')
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seckey = binascii.unhexlify(input())
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(r, Ri) = get_nonce(seckey, digest, ctr)
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h = ed25519raw.H(seckey)
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b = ed25519raw.b
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a = 2**(b - 2) + sum(2**i * ed25519raw.bit(h, i) for i in range(3, b - 2))
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S = (r + ed25519raw.Hint(R + pk + digest) * a) % ed25519raw.l
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print('Local commit: %s' % hex(Ri))
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print('Local sig: %s' % hex(ed25519raw.encodeint(S)))
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def combinePhase2(m):
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sigs = []
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print('Enter global commit: ', end='')
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R = binascii.unhexlify(input())
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for i in range(0, m):
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print('Enter sig %d: ' % i, end='')
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sigs.append(binascii.unhexlify(input()))
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sig = combine_sig(R, sigs)
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print('Combined sig: %s' % hex(sig))
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def checkSignature(data):
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digest = pyblake2.blake2s(data).digest()
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print('Digest: %s' % hex(digest))
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print('Enter Public Key: ', end='')
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pubkey = binascii.unhexlify(input())
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print('Enter Sig: ', end='')
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sig = binascii.unhexlify(input())
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ed25519raw.checkvalid(sig, digest, pubkey)
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print('Valid Signature!')
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def usage():
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print('Usage: keyctl phase options')
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print('Phases:')
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print(' keyctl create_pub: create single public keys')
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print(' keyctl combine_pub m n: create combined public keys')
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print(' keyctl ph1 file.bin: compute partial commitment')
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print(' keyctl combine_ph1 m: combine commitments')
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print(' keyctl ph2 file.bin: compute partial signature')
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print(' keyctl combine_ph2 m: combine signatures')
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print(' keyctl check_sig file.bin: check signature')
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def main():
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if len(sys.argv) < 2:
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usage()
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return 1
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func = sys.argv[1]
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if func == 'create_pub':
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createPubkey()
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elif func == 'combine_pub':
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m = int(sys.argv[2])
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n = int(sys.argv[3])
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combinePubkeys(m, n)
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elif func == 'ph1':
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filename = sys.argv[2]
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data = open(filename, 'rb').read()
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phase1(data)
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elif func == 'combine_ph1':
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m = int(sys.argv[2])
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combinePhase1(m)
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elif func == 'ph2':
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filename = sys.argv[2]
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data = open(filename, 'rb').read()
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phase2(data)
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elif func == 'combine_ph2':
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m = int(sys.argv[2])
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combinePhase2(m)
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elif func == 'check_sig':
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filename = sys.argv[2]
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data = open(filename, 'rb').read()
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checkSignature(data)
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else:
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usage()
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def test():
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data = sys.argv[1].encode('utf-8')
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N = 5
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keyset = [1, 3, 4]
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digest = pyblake2.blake2s(data).digest()
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print('Digest: %s' % hex(digest))
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sks = []
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pks = []
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nonces = []
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commits = []
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sigs = []
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for i in range(0, N):
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print('----- Key %d ------' % (i + 1))
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seckey = ed25519raw.H(("key%d" % (i + 1)).encode('utf-8'))[0:32]
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pubkey = ed25519raw.publickey(seckey)
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print('Secret Key: %s' % hex(seckey))
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print('Public Key: %s' % hex(pubkey))
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sks.append(seckey)
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pks.append(pubkey)
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ctr = 0
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(r, R) = get_nonce(seckey, digest, ctr)
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print('Local nonce: %s' % hex(ed25519raw.encodeint(r)))
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print('Local commit: %s' % hex(R))
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nonces.append(r)
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commits.append(R)
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globalPk = combine_keys([pks[i] for i in keyset])
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globalR = combine_keys([commits[i] for i in keyset])
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print('-----------------')
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print('Global pubkey: %s' % hex(globalPk))
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print('Global commit: %s' % hex(globalR))
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print('-----------------')
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for i in range(0, 5):
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seckey = sks[i]
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pubkey = pks[i]
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r = nonces[i]
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R = commits[i]
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h = ed25519raw.H(seckey)
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b = ed25519raw.b
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a = 2**(b - 2) + sum(2**i * ed25519raw.bit(h, i)
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for i in range(3, b - 2))
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S = (r + ed25519raw.Hint(globalR + globalPk + digest) * a) % ed25519raw.l
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print('Local sig %d: %s' % (i + 1, hex(ed25519raw.encodeint(S))))
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commits.append(R)
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sigs.append(ed25519raw.encodeint(S))
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print('-----------------')
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sig = combine_sig(globalR, [sigs[i] for i in [1, 3, 4]])
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print('Global sig: %s' % hex(sig))
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ed25519raw.checkvalid(sig, digest, globalPk)
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print('Valid Signature!')
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if __name__ == '__main__':
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test()
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