(PHP 7 >= 7.2.0, PHP 8)
sodium_crypto_kdf_derive_from_key — Derive a subkey
$subkey_length
, int $subkey_id
, string $context
, string $key
) : stringDerive a subkey from a root key and additional context.
Similar to hash_hkdf().
subkey_lengthLength of the key to return (in bytes)
subkey_idReturn the Nth subkey from a given root key. Useful for seeking.
contextApplication-specific context.
keyThe root key from which the subkey is derived.
A string of pseudorandom (raw binary) bytes.