1 // Copyright 2020 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // ////////////////////////////////////////////////////////////////////////////// 16 17 package com.google.crypto.tink.keyderivation; 18 19 import com.google.crypto.tink.KeysetHandle; 20 import com.google.errorprone.annotations.Immutable; 21 import java.security.GeneralSecurityException; 22 23 /** 24 * KeysetDeriver is the interface used to derive new keysets based on an additional input, the salt. 25 * 26 * <p>The {@code salt} is used to create the keyset using a pseudorandom function. Implementations 27 * must be indistinguishable from ideal KeysetDerivers, which, for every salt, generates a new 28 * random keyset and caches it. 29 */ 30 @Immutable 31 public interface KeysetDeriver { deriveKeyset(byte[] salt)32 KeysetHandle deriveKeyset(byte[] salt) throws GeneralSecurityException; 33 } 34