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trezor-firmware/trezorlib/tx_api.py
Jochen Hoenicke 69067c9280 Parse json floats as string
With python-2.7 the float values are sometimes rounded to unacceptable
levels, e.g. stripping the last two digits for values over 100k BTC.
This change parses floats as strings to avoid rounding.

Refactored get_url out of fetch_json to make it easier to add
new tx_api with a different url scheme.
2017-11-28 19:55:31 +01:00

188 lines
6.5 KiB
Python

# This file is part of the TREZOR project.
#
# Copyright (C) 2012-2016 Marek Palatinus <slush@satoshilabs.com>
# Copyright (C) 2012-2016 Pavol Rusnak <stick@satoshilabs.com>
# Copyright (C) 2016 Jochen Hoenicke <hoenicke@gmail.com>
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library. If not, see <http://www.gnu.org/licenses/>.
import binascii
from decimal import Decimal
import requests
import json
from . import types_pb2 as proto_types
cache_dir = None
class TxApi(object):
def __init__(self, network, url):
self.network = network
self.url = url
def get_url(self, resource, resourceid):
url = '%s%s/%s' % (self.url, resource, resourceid)
return url
def fetch_json(self, resource, resourceid):
global cache_dir
if cache_dir:
cache_file = '%s/%s_%s_%s.json' % (cache_dir, self.network, resource, resourceid)
try: # looking into cache first
j = json.load(open(cache_file), parse_float=str)
return j
except:
pass
try:
url = self.get_url(resource, resourceid)
r = requests.get(url, headers={'User-agent': 'Mozilla/5.0'})
j = r.json(parse_float=str)
except:
raise RuntimeError('URL error: %s' % url)
if cache_dir and cache_file:
try: # saving into cache
json.dump(j, open(cache_file, 'w'))
except:
pass
return j
def get_tx(self, txhash):
raise NotImplementedError
class TxApiInsight(TxApi):
def __init__(self, network, url, zcash=None):
super(TxApiInsight, self).__init__(network, url)
self.zcash = zcash
def get_tx(self, txhash):
data = self.fetch_json('tx', txhash)
t = proto_types.TransactionType()
t.version = data['version']
t.lock_time = data['locktime']
for vin in data['vin']:
i = t.inputs.add()
if 'coinbase' in vin.keys():
i.prev_hash = b"\0" * 32
i.prev_index = 0xffffffff # signed int -1
i.script_sig = binascii.unhexlify(vin['coinbase'])
i.sequence = vin['sequence']
else:
i.prev_hash = binascii.unhexlify(vin['txid'])
i.prev_index = vin['vout']
i.script_sig = binascii.unhexlify(vin['scriptSig']['hex'])
i.sequence = vin['sequence']
for vout in data['vout']:
o = t.bin_outputs.add()
o.amount = int(Decimal(vout['value']) * 100000000)
o.script_pubkey = binascii.unhexlify(vout['scriptPubKey']['hex'])
if self.zcash:
if t.version == 2:
joinsplit_cnt = len(data['vjoinsplit'])
if joinsplit_cnt == 0:
t.extra_data = b'\x00'
else:
if joinsplit_cnt >= 253:
# we assume cnt < 253, so we can treat varIntLen(cnt) as 1
raise ValueError('Too many joinsplits')
extra_data_len = 1 + joinsplit_cnt * 1802 + 32 + 64
raw = self.fetch_json('rawtx', txhash)
raw = binascii.unhexlify(raw['rawtx'])
t.extra_data = raw[-extra_data_len:]
return t
class TxApiSmartbit(TxApi):
def get_tx(self, txhash):
data = self.fetch_json('tx', txhash)
data = data['transaction']
t = proto_types.TransactionType()
t.version = int(data['version'])
t.lock_time = data['locktime']
for vin in data['inputs']:
i = t.inputs.add()
if 'coinbase' in vin.keys():
i.prev_hash = b"\0" * 32
i.prev_index = 0xffffffff # signed int -1
i.script_sig = binascii.unhexlify(vin['coinbase'])
i.sequence = vin['sequence']
else:
i.prev_hash = binascii.unhexlify(vin['txid'])
i.prev_index = vin['vout']
i.script_sig = binascii.unhexlify(vin['script_sig']['hex'])
i.sequence = vin['sequence']
for vout in data['outputs']:
o = t.bin_outputs.add()
o.amount = int(Decimal(vout['value']) * 100000000)
o.script_pubkey = binascii.unhexlify(vout['script_pub_key']['hex'])
return t
class TxApiBlockCypher(TxApi):
def get_tx(self, txhash):
data = self.fetch_json('txs', txhash)
t = proto_types.TransactionType()
t.version = data['ver']
t.lock_time = data['lock_time']
for vin in data['inputs']:
i = t.inputs.add()
if 'prev_hash' not in vin:
i.prev_hash = b"\0" * 32
i.prev_index = 0xffffffff # signed int -1
i.script_sig = binascii.unhexlify(vin['script'])
i.sequence = vin['sequence']
else:
i.prev_hash = binascii.unhexlify(vin['prev_hash'])
i.prev_index = vin['output_index']
i.script_sig = binascii.unhexlify(vin['script'])
i.sequence = vin['sequence']
for vout in data['outputs']:
o = t.bin_outputs.add()
o.amount = int(str(vout['value']), 10)
o.script_pubkey = binascii.unhexlify(vout['script'])
return t
TxApiBitcoin = TxApiInsight(network='insight_bitcoin', url='https://btc-bitcore1.trezor.io/api/')
TxApiTestnet = TxApiInsight(network='insight_testnet', url='https://testnet-bitcore3.trezor.io/api/')
TxApiLitecoin = TxApiInsight(network='insight_litecoin', url='https://ltc-bitcore1.trezor.io/api/')
TxApiDash = TxApiInsight(network='insight_dash', url='https://dash-bitcore1.trezor.io/api/')
TxApiZcash = TxApiInsight(network='insight_zcash', url='https://zec-bitcore1.trezor.io/api/', zcash=True)
TxApiBcash = TxApiInsight(network='insight_zcash', url='https://bch-bitcore2.trezor.io/api/')
TxApiSegnet = TxApiSmartbit(network='smartbit_segnet', url='https://segnet-api.smartbit.com.au/v1/blockchain/')