LBRY-Vault/electrum/plugins/revealer/revealer.py
2018-12-15 09:05:12 +01:00

105 lines
3.5 KiB
Python

import random
import os
from hashlib import sha256
from typing import NamedTuple, Optional, Dict, Tuple
from electrum.plugin import BasePlugin
from electrum.util import to_bytes, bh2u, bfh
from .hmac_drbg import DRBG
class VersionedSeed(NamedTuple):
version: str
seed: str
checksum: str
def get_ui_string_version_plus_seed(self):
version, seed = self.version, self.seed
assert isinstance(version, str) and len(version) == 1, version
assert isinstance(seed, str) and len(seed) >= 32
ret = version + seed
ret = ret.upper()
return ' '.join(ret[i : i+4] for i in range(0, len(ret), 4))
class RevealerPlugin(BasePlugin):
LATEST_VERSION = '1'
KNOWN_VERSIONS = ('0', '1')
assert LATEST_VERSION in KNOWN_VERSIONS
SIZE = (159, 97)
def __init__(self, parent, config, name):
BasePlugin.__init__(self, parent, config, name)
@classmethod
def code_hashid(cls, txt: str) -> str:
txt = txt.lower()
x = to_bytes(txt, 'utf8')
hash = sha256(x).hexdigest()
return hash[-3:].upper()
@classmethod
def get_versioned_seed_from_user_input(cls, txt: str) -> Optional[VersionedSeed]:
if len(txt) < 34:
return None
try:
int(txt, 16)
except:
return None
version = txt[0]
if version not in cls.KNOWN_VERSIONS:
return None
checksum = cls.code_hashid(txt[:-3])
if txt[-3:].upper() != checksum.upper():
return None
return VersionedSeed(version=version.upper(),
seed=txt[1:-3].upper(),
checksum=checksum.upper())
@classmethod
def get_noise_map(cls, versioned_seed: VersionedSeed) -> Dict[Tuple[int, int], int]:
"""Returns a map from (x,y) coordinate to pixel value 0/1, to be used as rawnoise."""
w, h = cls.SIZE
version = versioned_seed.version
hex_seed = versioned_seed.seed
checksum = versioned_seed.checksum
noise_map = {}
if version == '0':
random.seed(int(hex_seed, 16))
for x in range(w):
for y in range(h):
noise_map[(x, y)] = random.randint(0, 1)
elif version == '1':
prng_seed = bfh(hex_seed + version + checksum)
drbg = DRBG(prng_seed)
num_noise_bytes = 1929 # ~ w*h
noise_array = bin(int.from_bytes(drbg.generate(num_noise_bytes), 'big'))[2:]
# there's an approx 1/1024 chance that the generated number is 'too small'
# and we would get IndexError below. easiest backwards compat fix:
noise_array += '0' * (w * h - len(noise_array))
i = 0
for x in range(w):
for y in range(h):
noise_map[(x, y)] = int(noise_array[i])
i += 1
else:
raise Exception(f"unexpected revealer version: {version}")
return noise_map
@classmethod
def gen_random_versioned_seed(cls):
version = cls.LATEST_VERSION
hex_seed = bh2u(os.urandom(16))
checksum = cls.code_hashid(version + hex_seed)
return VersionedSeed(version=version.upper(),
seed=hex_seed.upper(),
checksum=checksum.upper())
if __name__ == '__main__':
for i in range(10**4):
vs = RevealerPlugin.gen_random_versioned_seed()
nm = RevealerPlugin.get_noise_map(vs)