// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// //////////////////////////////////////////////////////////////////////////////

package com.google.crypto.tink.keyderivation;

import com.google.crypto.tink.KeysetHandle;
import com.google.errorprone.annotations.Immutable;
import java.security.GeneralSecurityException;

/**
 * KeysetDeriver is the interface used to derive new keysets based on an additional input, the salt.
 *
 * <p>The {@code salt} is used to create the keyset using a pseudorandom function. Implementations
 * must be indistinguishable from ideal KeysetDerivers, which, for every salt, generates a new
 * random keyset and caches it.
 */
@Immutable
public interface KeysetDeriver {
  KeysetHandle deriveKeyset(byte[] salt) throws GeneralSecurityException;
}