PHP Manual: Derive a subkey

Description

string sodium_crypto_kdf_derive_from_key(
    int $subkey_length,
    int $subkey_id,
    string $context,
    #[\SensitiveParameter]string $key
)

Derive a subkey from a root key and additional context.

Similar to hash_hkdf.

Parameters

subkey_length: Length of the key to return (in bytes)
subkey_id: Return the Nth subkey from a given root key. Useful for seeking.
context: Application-specific context.
key: The root key from which the subkey is derived.

Return Values

A string of pseudorandom (raw binary) bytes.