lokinet/contrib/hex-to-base32z.py

62 lines
1.8 KiB
Python
Raw Permalink Normal View History

#!/usr/bin/python3
import sys
base32z_dict = 'ybndrfg8ejkmcpqxot1uwisza345h769'
base32z_map = {base32z_dict[i]: i for i in range(len(base32z_dict))}
def lokinet_snode_addr(pk_hex):
"""Returns the lokinet snode address from a hex ed25519 pubkey"""
assert(len(pk_hex) == 64)
bits = 0
val = 0
result = ''
for x in pk_hex:
bits += 4
val = (val << 4) + int(x, 16)
if bits >= 5:
bits -= 5
v = val >> bits
val &= (1 << bits) - 1
result += base32z_dict[v]
result += base32z_dict[val << (5 - bits)]
return result + ".snode"
def hex_from_snode(b32z):
"""undoes what the above does; b32z should have '.snode' already stripped off"""
assert(len(b32z) == 52)
val = 0
bits = 0
for x in b32z:
val = (val << 5) | base32z_map[x] # Arbitrary precision integers FTW
# `val` is now a 260 bit value (52 * 5 bits per char); but we only use the first bit of the last
# value (which is why lokinet addresses always end with y or o)
assert(b32z[-1] in 'yo')
val >>= 4
return "{:64x}".format(val)
reverse = False
if len(sys.argv) >= 2 and sys.argv[1] == '-r':
reverse = True
del sys.argv[1]
if len(sys.argv) < 2 or (
any(len(x) not in (52, 58) for x in sys.argv[1:])
if reverse else
any(len(x) != 64 for x in sys.argv[1:])
):
print("Usage: {} PUBKEY [PUBKEY ...] -- converts ed25519 pubkeys to .snode addresses".format(sys.argv[0]))
print("Usage: {} -r SNODE [SNODE ...] -- converts snode addresses to ed25519 pubkeys".format(sys.argv[0]))
sys.exit(1)
if reverse:
for key in sys.argv[1:]:
print("{}.snode -> {}".format(key[0:52], hex_from_snode(key[0:52])))
else:
for key in sys.argv[1:]:
print("{} -> {}".format(key, lokinet_snode_addr(key)))