1 // Copyright 2024 Google Inc. 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.internal; 18 19 import static com.google.common.truth.Truth.assertThat; 20 21 import com.google.crypto.tink.util.Bytes; 22 import org.junit.Test; 23 import org.junit.runner.RunWith; 24 import org.junit.runners.JUnit4; 25 26 @RunWith(JUnit4.class) 27 public final class OutputPrefixUtilTest { 28 29 @Test getTinkOutputPrefix_works()30 public void getTinkOutputPrefix_works() { 31 Bytes prefix = OutputPrefixUtil.getTinkOutputPrefix(0x12345678); 32 assertThat(prefix) 33 .isEqualTo( 34 Bytes.copyFrom( 35 new byte[] {(byte) 0x01, (byte) 0x12, (byte) 0x34, (byte) 0x56, (byte) 0x78})); 36 assertThat(prefix.size()).isEqualTo(OutputPrefixUtil.NON_EMPTY_PREFIX_SIZE); 37 } 38 39 @Test getLegacyOutputPrefix_works()40 public void getLegacyOutputPrefix_works() { 41 Bytes prefix = OutputPrefixUtil.getLegacyOutputPrefix(0x12345678); 42 assertThat(prefix) 43 .isEqualTo( 44 Bytes.copyFrom( 45 new byte[] {(byte) 0x00, (byte) 0x12, (byte) 0x34, (byte) 0x56, (byte) 0x78})); 46 assertThat(prefix.size()).isEqualTo(OutputPrefixUtil.NON_EMPTY_PREFIX_SIZE); 47 } 48 49 @Test emptyPrefix_isEmpty()50 public void emptyPrefix_isEmpty() { 51 assertThat(OutputPrefixUtil.EMPTY_PREFIX).isEqualTo(Bytes.copyFrom(new byte[] {})); 52 } 53 } 54