HMAC is a keyed-hash message authentication code computed involving a cryptographic hash function in combination with a secret cryptographic key. It can be used to simultaneously verify both the data integrity and the authentication of a message.
---HTTP_REQ or HTTP_RESP
host = avi.http.get_header("Host")
-- if host header exists
if host then
avi.http.add_header("Murmur-hash", avi.utils.murmur_hash(host))
avi.http.add_header("SHA1-hash", avi.utils.sha1_hash(host))
avi.http.add_header("MD5-hash", avi.utils.md5_hash(host))
end