def b58check_encode(bin_s, version_byte=0):
""" Takes in a binary string and converts it to a base 58 check string. """
# append the version byte to the beginning
bin_s = chr(int(version_byte)) + bin_s
# calculate the number of leading zeros
num_leading_zeros = len(re.match(r'^\x00*', bin_s).group(0))
# add in the checksum add the end
bin_s = bin_s + bin_checksum(bin_s)
# convert from b2 to b16
hex_s = binascii.hexlify(bin_s)
# convert from b16 to b58
b58_s = change_charset(hex_s, HEX_KEYSPACE, B58_KEYSPACE)
return B58_KEYSPACE[0] * num_leading_zeros + b58_s
def b58check_encode(bin_s, version_byte=0):
""" Takes in a binary string and converts it to a base 58 check string. """
# append the version byte to the beginning
bin_s = chr(int(version_byte)) + bin_s
# calculate the number of leading zeros
num_leading_zeros = len(re.match(r'^\x00*', bin_s).group(0))
# add in the checksum add the end
bin_s = bin_s + bin_checksum(bin_s)
# convert from b2 to b16
hex_s = binascii.hexlify(bin_s)
# convert from b16 to b58
b58_s = change_charset(hex_s, HEX_KEYSPACE, B58_KEYSPACE)
return B58_KEYSPACE[0] * num_leading_zeros + b58_s
def b58check_unpack(b58_s):
""" Takes in a base 58 check string and returns: the version byte, the
original encoded binary string, and the checksum.
"""
num_leading_zeros = len(re.match(r'^1*', b58_s).group(0))
# convert from b58 to b16
hex_s = change_charset(b58_s, B58_KEYSPACE, HEX_KEYSPACE)
# convert from b16 to b2
bin_s = binascii.unhexlify(hex_s)
# add in the leading zeros
bin_s = '\x00' * num_leading_zeros + bin_s
# make sure the newly calculated checksum equals the embedded checksum
newly_calculated_checksum = bin_checksum(bin_s[:-4])
embedded_checksum = bin_s[-4:]
assert(newly_calculated_checksum == embedded_checksum)
# return values
version_byte = bin_s[:1]
encoded_value = bin_s[1:-4]
checksum = bin_s[-4:]
return version_byte, encoded_value, checksum
def b58check_unpack(b58_s):
""" Takes in a base 58 check string and returns: the version byte, the
original encoded binary string, and the checksum.
"""
num_leading_zeros = len(re.match(r'^1*', b58_s).group(0))
# convert from b58 to b16
hex_s = change_charset(b58_s, B58_KEYSPACE, HEX_KEYSPACE)
# if an odd number of hex characters are present, add a zero to the front
if len(hex_s) % 2 == 1:
hex_s = "0" + hex_s
# convert from b16 to b2
bin_s = binascii.unhexlify(hex_s)
# add in the leading zeros
bin_s = '\x00' * num_leading_zeros + bin_s
# make sure the newly calculated checksum equals the embedded checksum
newly_calculated_checksum = bin_checksum(bin_s[:-4])
embedded_checksum = bin_s[-4:]
assert (newly_calculated_checksum == embedded_checksum)
# return values
version_byte = bin_s[:1]
encoded_value = bin_s[1:-4]
checksum = bin_s[-4:]
return version_byte, encoded_value, checksum
