def hkdf_expand(salt, info, shared_secret):
from cryptography.hazmat.primitives import hashes<EOL>from cryptography.hazmat.primitives.kdf.hkdf import HKDF<EOL>from cryptography.hazmat.backends import default_backend<EOL>hkdf = HKDF(<EOL>algorithm=hashes.SHA512(),<EOL>length=<NUM_LIT:32>,<EOL>salt=salt.encode(),<EOL>info=info.encode(),<EOL>backend=default_backend()<EOL>)<EOL>return hkdf.derive(shared_secret)<EOL>
Derive encryption keys from shared secret.