def decode(prefix, addr):
"""Decode a cashaddr address."""
prefixgot, data = disassemble(addr, prefix)
if prefixgot != prefix:
return (None, None)
decoded = convertbits(data, 5, 8, False)
if decoded is None or not len(decoded):
return (None, None)
ver = (decoded[0] & 0x78) >> 3
return (ver, decoded[1:])
def decode(hrp, addr):
"""Decode a segwit address."""
hrpgot, data = bech32_decode(addr)
if hrpgot != hrp:
return (None, None)
decoded = convertbits(data[1:], 5, 8, False)
if decoded is None or len(decoded) < 2 or len(decoded) > 40:
return (None, None)
if data[0] > 16:
return (None, None)
if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
return (None, None)
return (data[0], decoded)
def valid_version(data):
"""Check that the version is correct for the data.
Do not include the checksum."""
converted = convertbits(data, 5, 8, False)
if converted == None:
return False
ver = converted[0]
# First bit is reserved
if ver & (1 << 8):
return False
# Last three bits specify the length we expect
bits = 160 + (ver & 3) * 32
# Bit six is a multiplier
if ver & 4:
bits *= 2
if (len(converted) - 1) != (bits / 8):
return False
return True
def encode(prefix, ver, data):
"""Encode a cashaddr address."""
if not len(data) in [20, 24, 28, 32, 40, 48, 56, 64]:
# Make sure length is valid.
return None
if not (0 <= ver <= 1 or ver == 15):
# Only versions (type) 1,2 and 15 are supported.
return None
ver <<= 3
dlen = 0
tmp = len(data) * 8
if tmp > 256:
dlen ^= 0x04
tmp /= 2
dlen += (tmp - 160) / 32
ver += dlen
bits = convertbits([ver] + data, 8, 5)
ret = assemble(prefix, bits)
if decode(prefix, ret) == (None, None):
return None
return ret
def encode(hrp, witver, witprog):
"""Encode a segwit address."""
ret = bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5))
if decode(hrp, ret) == (None, None):
return None
return ret