def auth_counterparty(self, nick, cr):
#deserialize the commitment revelation
cr_dict = btc.PoDLE.deserialize_revelation(cr)
#check the validity of the proof of discrete log equivalence
tries = jm_single().config.getint("POLICY", "taker_utxo_retries")
def reject(msg):
log.info("Counterparty commitment not accepted, reason: " + msg)
return False
if not btc.verify_podle(cr_dict['P'], cr_dict['P2'], cr_dict['sig'],
cr_dict['e'], self.maker.commit,
index_range=range(tries)):
reason = "verify_podle failed"
return reject(reason)
#finally, check that the proffered utxo is real, old enough, large enough,
#and corresponds to the pubkey
res = jm_single().bc_interface.query_utxo_set([cr_dict['utxo']],
includeconf=True)
if len(res) != 1 or not res[0]:
reason = "authorizing utxo is not valid"
return reject(reason)
age = jm_single().config.getint("POLICY", "taker_utxo_age")
if res[0]['confirms'] < age:
reason = "commitment utxo not old enough: " + str(res[0]['confirms'])
return reject(reason)
reqd_amt = int(self.cj_amount * jm_single().config.getint(
"POLICY", "taker_utxo_amtpercent") / 100.0)
if res[0]['value'] < reqd_amt:
reason = "commitment utxo too small: " + str(res[0]['value'])
return reject(reason)
if res[0]['address'] != btc.pubkey_to_address(cr_dict['P'],
get_p2pk_vbyte()):
reason = "Invalid podle pubkey: " + str(cr_dict['P'])
return reject(reason)
# authorisation of taker passed
# Send auth request to taker
# Need to choose an input utxo pubkey to sign with
# (no longer using the coinjoin pubkey from 0.2.0)
# Just choose the first utxo in self.utxos and retrieve key from wallet.
auth_address = self.utxos[self.utxos.keys()[0]]['address']
auth_key = self.maker.wallet.get_key_from_addr(auth_address)
auth_pub = btc.privtopub(auth_key)
btc_sig = btc.ecdsa_sign(self.kp.hex_pk(), auth_key)
self.maker.msgchan.send_ioauth(nick, self.utxos.keys(), auth_pub,
self.cj_addr, self.change_addr, btc_sig)
#In case of *blacklisted (ie already used) commitments, we already
#broadcasted them on receipt; in case of valid, and now used commitments,
#we broadcast them here, and not early - to avoid accidentally
#blacklisting commitments that are broadcast between makers in real time
#for the same transaction.
self.maker.transfer_commitment(self.maker.commit)
#now persist the fact that the commitment is actually used.
check_utxo_blacklist(self.maker.commit, persist=True)
return True
def test_rand_commitments(setup_podle):
#TODO bottleneck i believe is tweak_mul due
#to incorrect lack of precomputed context in upstream library.
for i in range(20):
priv = os.urandom(32)
Pser, P2ser, s, e, commitment = generate_single_podle_sig(priv, 1 + i%5)
assert btc.verify_podle(Pser, P2ser, s, e, commitment)
#tweak commitments to verify failure
tweaked = [x[::-1] for x in [Pser, P2ser, s, e, commitment]]
for i in range(5):
#Check failure on garbling of each parameter
y = [Pser, P2ser, s, e, commitment]
y[i] = tweaked[i]
fail = False
try:
fail = btc.verify_podle(*y)
except:
pass
finally:
assert not fail
def test_rand_commitments(setup_podle):
#TODO bottleneck i believe is tweak_mul due
#to incorrect lack of precomputed context in upstream library.
for i in range(20):
priv = os.urandom(32)
Pser, P2ser, s, e, commitment = generate_single_podle_sig(
priv, 1 + i % 5)
assert btc.verify_podle(Pser, P2ser, s, e, commitment)
#tweak commitments to verify failure
tweaked = [x[::-1] for x in [Pser, P2ser, s, e, commitment]]
for i in range(5):
#Check failure on garbling of each parameter
y = [Pser, P2ser, s, e, commitment]
y[i] = tweaked[i]
fail = False
try:
fail = btc.verify_podle(*y)
except:
pass
finally:
assert not fail
def auth_counterparty(self, nick, cr):
#deserialize the commitment revelation
cr_dict = btc.PoDLE.deserialize_revelation(cr)
#check the validity of the proof of discrete log equivalence
tries = jm_single().config.getint("POLICY", "taker_utxo_retries")
def reject(msg):
log.debug("Counterparty commitment not accepted, reason: " + msg)
return False
if not btc.verify_podle(cr_dict['P'],
cr_dict['P2'],
cr_dict['sig'],
cr_dict['e'],
self.maker.commit,
index_range=range(tries)):
reason = "verify_podle failed"
return reject(reason)
#finally, check that the proffered utxo is real, old enough, large enough,
#and corresponds to the pubkey
res = jm_single().bc_interface.query_utxo_set([cr_dict['utxo']],
includeconf=True)
if len(res) != 1 or not res[0]:
reason = "authorizing utxo is not valid"
return reject(reason)
age = jm_single().config.getint("POLICY", "taker_utxo_age")
if res[0]['confirms'] < age:
reason = "commitment utxo not old enough: " + str(
res[0]['confirms'])
return reject(reason)
reqd_amt = int(
self.cj_amount *
jm_single().config.getint("POLICY", "taker_utxo_amtpercent") /
100.0)
if res[0]['value'] < reqd_amt:
reason = "commitment utxo too small: " + str(res[0]['value'])
return reject(reason)
if res[0]['address'] != btc.pubkey_to_address(cr_dict['P'],
get_p2pk_vbyte()):
reason = "Invalid podle pubkey: " + str(cr_dict['P'])
return reject(reason)
# authorisation of taker passed
# Send auth request to taker
# Need to choose an input utxo pubkey to sign with
# (no longer using the coinjoin pubkey from 0.2.0)
# Just choose the first utxo in self.utxos and retrieve key from wallet.
auth_address = self.utxos[self.utxos.keys()[0]]['address']
auth_key = self.maker.wallet.get_key_from_addr(auth_address)
auth_pub = btc.privtopub(auth_key)
btc_sig = btc.ecdsa_sign(self.kp.hex_pk(), auth_key)
self.maker.msgchan.send_ioauth(nick, self.utxos.keys(), auth_pub,
self.cj_addr, self.change_addr, btc_sig)
#In case of *blacklisted (ie already used) commitments, we already
#broadcasted them on receipt; in case of valid, and now used commitments,
#we broadcast them here, and not early - to avoid accidentally
#blacklisting commitments that are broadcast between makers in real time
#for the same transaction.
self.maker.transfer_commitment(self.maker.commit)
#now persist the fact that the commitment is actually used.
check_utxo_blacklist(self.maker.commit, persist=True)
return True