extract
The "extract" part of HKDF with SecureByteString input key material.
Return
a pseudorandom key as a SecretKey.
Parameters
algorithm
the KDF algorithm to use e.g. Algorithm.HMAC_SHA256.
ikm
input key material as a SecureByteString.
salt
optional salt value (a non-secret random value).
Throws
if the algorithm is not supported.
if ikm has been destroyed.