def get_dust_return_pubkey(source, provided_pubkeys, encoding):
"""Return the pubkey to which dust from data outputs will be sent.
This pubkey is used in multi-sig data outputs (as the only real pubkey) to
make those the outputs spendable. It is derived from the source address, so
that the dust is spendable by the creator of the transaction.
"""
# Get hex dust return pubkey.
if script.is_multisig(source):
a, self_pubkeys, b = script.extract_array(backend.multisig_pubkeyhashes_to_pubkeys(source, provided_pubkeys))
dust_return_pubkey_hex = self_pubkeys[0]
else:
dust_return_pubkey_hex = backend.pubkeyhash_to_pubkey(source, provided_pubkeys)
# Convert hex public key into the (binary) dust return pubkey.
try:
dust_return_pubkey = binascii.unhexlify(dust_return_pubkey_hex)
except binascii.Error:
raise script.InputError('Invalid private key.')
return dust_return_pubkey
def search_pubkey(pubkeyhash, provided_pubkeys=None):
return backend.pubkeyhash_to_pubkey(pubkeyhash, provided_pubkeys=provided_pubkeys)
