hash160 may not always work

[Eunovo]

The hash160 implementation at

python-bip380/bip380/utils/hashes.py

Lines 14 to 17 in d2f5d8f

	def hash160(data):
	"""{data} must be bytes, returns ripemd160(sha256(data))"""
	assert isinstance(data, bytes)
	return hashlib.new("ripemd160", sha256(data)).digest()

uses hashlib to create a ripemd160 digest. The ripemd160 digest is not among hashlib's guaranteed algorigthms so this function may fail on some platforms with a ValueError: unsupported hash type ripemd message. I experienced this while trying to run liana's tests.

Would it be a bad idea to check for the presence of 'ripemd160' in hashlib.algorithms_available and output an appropriate error message before trying to create the ripemd160 digest?

[darosior]

I think we should use Bitcoin Core's Python implementation from bitcoin/bitcoin#23716.

[darosior]

Also relevant, what we did for Python-bip32: darosior/python-bip32#33 (link to the file: https://github.com/darosior/python-bip32/blob/master/bip32/ripemd160.py).