forked from LBRYCommunity/lbry-sdk
588edf98be
-move all leveldb prefixes to DB_PREFIXES enum -add serializable RevertableOp interface for key/value puts and deletes -resolve urls from leveldb
160 lines
4.5 KiB
Python
160 lines
4.5 KiB
Python
# Copyright (c) 2016-2017, Neil Booth
|
|
#
|
|
# All rights reserved.
|
|
#
|
|
# The MIT License (MIT)
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining
|
|
# a copy of this software and associated documentation files (the
|
|
# "Software"), to deal in the Software without restriction, including
|
|
# without limitation the rights to use, copy, modify, merge, publish,
|
|
# distribute, sublicense, and/or sell copies of the Software, and to
|
|
# permit persons to whom the Software is furnished to do so, subject to
|
|
# the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be
|
|
# included in all copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
|
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
|
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
"""Cryptograph hash functions and related classes."""
|
|
|
|
|
|
import hashlib
|
|
import hmac
|
|
|
|
from lbry.wallet.server.util import bytes_to_int, int_to_bytes, hex_to_bytes
|
|
|
|
_sha256 = hashlib.sha256
|
|
_sha512 = hashlib.sha512
|
|
_new_hash = hashlib.new
|
|
_new_hmac = hmac.new
|
|
HASHX_LEN = 11
|
|
CLAIM_HASH_LEN = 20
|
|
|
|
|
|
def sha256(x):
|
|
"""Simple wrapper of hashlib sha256."""
|
|
return _sha256(x).digest()
|
|
|
|
|
|
def ripemd160(x):
|
|
"""Simple wrapper of hashlib ripemd160."""
|
|
h = _new_hash('ripemd160')
|
|
h.update(x)
|
|
return h.digest()
|
|
|
|
|
|
def double_sha256(x):
|
|
"""SHA-256 of SHA-256, as used extensively in bitcoin."""
|
|
return sha256(sha256(x))
|
|
|
|
|
|
def hmac_sha512(key, msg):
|
|
"""Use SHA-512 to provide an HMAC."""
|
|
return _new_hmac(key, msg, _sha512).digest()
|
|
|
|
|
|
def hash160(x):
|
|
"""RIPEMD-160 of SHA-256.
|
|
|
|
Used to make bitcoin addresses from pubkeys."""
|
|
return ripemd160(sha256(x))
|
|
|
|
|
|
def hash_to_hex_str(x: bytes) -> str:
|
|
"""Convert a big-endian binary hash to displayed hex string.
|
|
|
|
Display form of a binary hash is reversed and converted to hex.
|
|
"""
|
|
return x[::-1].hex()
|
|
|
|
|
|
def hex_str_to_hash(x: str) -> bytes:
|
|
"""Convert a displayed hex string to a binary hash."""
|
|
return hex_to_bytes(x)[::-1]
|
|
|
|
|
|
class Base58Error(Exception):
|
|
"""Exception used for Base58 errors."""
|
|
|
|
|
|
class Base58:
|
|
"""Class providing base 58 functionality."""
|
|
|
|
chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
|
|
assert len(chars) == 58
|
|
cmap = {c: n for n, c in enumerate(chars)}
|
|
|
|
@staticmethod
|
|
def char_value(c):
|
|
val = Base58.cmap.get(c)
|
|
if val is None:
|
|
raise Base58Error(f'invalid base 58 character "{c}"')
|
|
return val
|
|
|
|
@staticmethod
|
|
def decode(txt):
|
|
"""Decodes txt into a big-endian bytearray."""
|
|
if not isinstance(txt, str):
|
|
raise TypeError('a string is required')
|
|
|
|
if not txt:
|
|
raise Base58Error('string cannot be empty')
|
|
|
|
value = 0
|
|
for c in txt:
|
|
value = value * 58 + Base58.char_value(c)
|
|
|
|
result = int_to_bytes(value)
|
|
|
|
# Prepend leading zero bytes if necessary
|
|
count = 0
|
|
for c in txt:
|
|
if c != '1':
|
|
break
|
|
count += 1
|
|
if count:
|
|
result = bytes(count) + result
|
|
|
|
return result
|
|
|
|
@staticmethod
|
|
def encode(be_bytes):
|
|
"""Converts a big-endian bytearray into a base58 string."""
|
|
value = bytes_to_int(be_bytes)
|
|
|
|
txt = ''
|
|
while value:
|
|
value, mod = divmod(value, 58)
|
|
txt += Base58.chars[mod]
|
|
|
|
for byte in be_bytes:
|
|
if byte != 0:
|
|
break
|
|
txt += '1'
|
|
|
|
return txt[::-1]
|
|
|
|
@staticmethod
|
|
def decode_check(txt, *, hash_fn=double_sha256):
|
|
"""Decodes a Base58Check-encoded string to a payload. The version
|
|
prefixes it."""
|
|
be_bytes = Base58.decode(txt)
|
|
result, check = be_bytes[:-4], be_bytes[-4:]
|
|
if check != hash_fn(result)[:4]:
|
|
raise Base58Error(f'invalid base 58 checksum for {txt}')
|
|
return result
|
|
|
|
@staticmethod
|
|
def encode_check(payload, *, hash_fn=double_sha256):
|
|
"""Encodes a payload bytearray (which includes the version byte(s))
|
|
into a Base58Check string."""
|
|
be_bytes = payload + hash_fn(payload)[:4]
|
|
return Base58.encode(be_bytes)
|