// Copyright 2016 The Nomulus Authors. All Rights Reserved.
//
// 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 google.registry.util;

import static com.google.common.io.BaseEncoding.base64;
import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.testing.EqualsTester;
import google.registry.testing.ExceptionRule;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.Arrays;
import java.util.zip.GZIPInputStream;
import org.joda.time.DateTime;
import org.joda.time.format.ISODateTimeFormat;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Unit tests for {@link PosixTarHeader}. */
@RunWith(JUnit4.class)
public class PosixTarHeaderTest {

  @Rule
  public final ExceptionRule thrown = new ExceptionRule();

  @Test
  public void testGnuTarBlob() throws Exception {
    // This data was generated as follows:
    //
    //   echo hello kitty >hello.xml
    //   tar --format=ustar -cf ~/hello.tar hello.xml
    //   head -c 1024 <hello.tar | base64
    //
    // As you can see, we're only going to bother with the first 1024 characters.
    byte[] gnuTarGeneratedData = base64().decode(""
        + "aGVsbG8ueG1sAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAADAwMDA2NDAAMDU0MTI2"
        + "NgAwMDExNjEwADAwMDAwMDAwMDE0ADEyMjAyMzEwMzI0ADAxMjQ2MQAgMAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAB1c3RhcgAwMGphcnQAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAZW5nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAwMDAwMDAwADAwMDAw"
        + "MDAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABo"
        + "ZWxsbyBraXR0eQoAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
        + "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==");
    assertThat(gnuTarGeneratedData.length).isEqualTo(1024);

    // Now we have to replicate it.
    byte[] data = "hello kitty\n".getBytes(UTF_8);
    PosixTarHeader header = new PosixTarHeader.Builder()
        .setType(PosixTarHeader.Type.REGULAR)
        .setName("hello.xml")
        .setSize(data.length)
        .setMode(0640)
        // This timestamp should have been midnight but I think GNU tar might not understand
        // daylight savings time. Woe is me.
        .setMtime(DateTime.parse("2013-08-13T01:50:12Z"))
        .setUname("jart")
        .setGname("eng")
        .setUid(180918)  // echo $UID
        .setGid(5000)  // import grp; print grp.getgrnam('eng').gr_gid
        .build();
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    output.write(header.getBytes());
    output.write(data);
    // Line up with the 512-byte block boundary.
    if (data.length % 512 != 0) {
      output.write(new byte[512 - data.length % 512]);
    }
    output.write(new byte[1024]);  // Bunch of null bytes to indicate end of archive.
    byte[] tarData = output.toByteArray();
    assertThat(tarData.length % 512).isEqualTo(0);
    data = Arrays.copyOf(tarData, 1024);

    // From Wikipedia:
    // The checksum is calculated by taking the sum of the unsigned byte values of the header
    // record with the eight checksum bytes taken to be ascii spaces (decimal value 32). It is
    // stored as a six digit octal number with leading zeroes followed by a NUL and then a space.
    // Various implementations do not adhere to this format. For better compatibility, ignore
    // leading and trailing whitespace, and get the first six digits. In addition, some historic
    // tar implementations treated bytes as signed. Implementations typically calculate the
    // checksum both ways, and treat it as good if either the signed or unsigned sum matches the
    // included checksum.
    data[155] = ' ';

    // Compare everything in the arrays except for the checksum. That way we know what's causing
    // the checksum to fail.
    byte[] gnuTarGeneratedDataNoChksum = gnuTarGeneratedData.clone();
    Arrays.fill(gnuTarGeneratedDataNoChksum, 148, 148 + 8, (byte) 0);
    byte[] dataNoChksum = data.clone();
    Arrays.fill(dataNoChksum, 148, 148 + 8, (byte) 0);
    assertThat(dataNoChksum).isEqualTo(gnuTarGeneratedDataNoChksum);

    // Now do it again with the checksum.
    assertThat(data).isEqualTo(gnuTarGeneratedData);
  }

  @Test
  public void testFields() throws Exception {
    PosixTarHeader header = new PosixTarHeader.Builder()
        .setType(PosixTarHeader.Type.REGULAR)
        .setName("(◕‿◕).txt")
        .setSize(666)
        .setMode(0777)
        .setMtime(DateTime.parse("1984-12-18T04:20:00Z"))
        .setUname("everything i ever touched")
        .setGname("everything i ever had, has died")
        .setUid(180918)
        .setGid(5000)
        .build();
    assertThat(header.getType()).isEqualTo(PosixTarHeader.Type.REGULAR);
    assertThat(header.getName()).isEqualTo("(◕‿◕).txt");
    assertThat(header.getSize()).isEqualTo(666);
    assertThat(header.getMode()).isEqualTo(0777);
    assertThat(header.getUname()).isEqualTo("everything i ever touched");
    assertThat(header.getGname()).isEqualTo("everything i ever had, has died");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(5000);
    assertThat(header.getMtime()).isEqualTo(DateTime.parse("1984-12-18T04:20:00Z"));
    assertThat(header.getMagic()).isEqualTo("ustar");
    assertThat(header.getVersion()).isEqualTo("00");
  }

  @Test
  public void testFieldsSomeMoar() throws Exception {
    PosixTarHeader header = new PosixTarHeader.Builder()
        .setType(PosixTarHeader.Type.DIRECTORY)
        .setName("Black lung full of fumes, choke on memories")
        .setSize(1024 * 1024 * 1024)
        .setMode(31337)
        .setMtime(DateTime.parse("2020-12-18T04:20:00Z"))
        .setUname("every street i ever walked")
        .setGname("every home i ever had, is lost")
        .setUid(0)
        .setGid(31337)
        .build();
    assertThat(header.getType()).isEqualTo(PosixTarHeader.Type.DIRECTORY);
    assertThat(header.getName()).isEqualTo("Black lung full of fumes, choke on memories");
    assertThat(header.getSize()).isEqualTo(1024 * 1024 * 1024);
    assertThat(header.getMode()).isEqualTo(31337);
    assertThat(header.getUname()).isEqualTo("every street i ever walked");
    assertThat(header.getGname()).isEqualTo("every home i ever had, is lost");
    assertThat(header.getUid()).isEqualTo(0);
    assertThat(header.getGid()).isEqualTo(31337);
    assertThat(header.getMtime()).isEqualTo(DateTime.parse("2020-12-18T04:20:00Z"));
  }

  @Test
  public void testLoad() throws Exception {
    PosixTarHeader header = new PosixTarHeader.Builder()
        .setType(PosixTarHeader.Type.REGULAR)
        .setName("(◕‿◕).txt")
        .setSize(31337)
        .setMode(0777)
        .setMtime(DateTime.parse("1984-12-18T04:20:00Z"))
        .setUname("everything i ever touched")
        .setGname("everything i ever had, has died")
        .setUid(180918)
        .setGid(5000)
        .build();
    header = PosixTarHeader.from(header.getBytes());  // <-- Pay attention to this line.
    assertThat(header.getType()).isEqualTo(PosixTarHeader.Type.REGULAR);
    assertThat(header.getName()).isEqualTo("(◕‿◕).txt");
    assertThat(header.getSize()).isEqualTo(31337);
    assertThat(header.getMode()).isEqualTo(0777);
    assertThat(header.getUname()).isEqualTo("everything i ever touched");
    assertThat(header.getGname()).isEqualTo("everything i ever had, has died");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(5000);
    assertThat(header.getMtime()).isEqualTo(DateTime.parse("1984-12-18T04:20:00Z"));
    assertThat(header.getMagic()).isEqualTo("ustar");
    assertThat(header.getVersion()).isEqualTo("00");
  }

  @Test
  public void testBadChecksum() throws Exception {
    PosixTarHeader header = new PosixTarHeader.Builder()
        .setName("(◕‿◕).txt")
        .setSize(31337)
        .build();
    byte[] bytes = header.getBytes();
    bytes[150] = '0';
    bytes[151] = '0';
    thrown.expect(IllegalArgumentException.class, "chksum invalid");
    PosixTarHeader.from(bytes);
  }

  @Test
  public void testHashEquals() throws Exception {
    new EqualsTester()
        .addEqualityGroup(
            new PosixTarHeader.Builder()
                .setName("(◕‿◕).txt")
                .setSize(123)
                .setMtime(DateTime.parse("1984-12-18TZ"))
                .setUid(1234)
                .setGid(456)
                .setUname("jart")
                .setGname("wheel")
                .build(),
            new PosixTarHeader.Builder()
                .setName("(◕‿◕).txt")
                .setSize(123)
                .setMtime(DateTime.parse("1984-12-18TZ"))
                .setUid(1234)
                .setGid(456)
                .setUname("jart")
                .setGname("wheel")
                .build())
        .addEqualityGroup(
            new PosixTarHeader.Builder()
                .setName("(•︵•).txt")  // Awwwww! It looks so sad...
                .setSize(123)
                .build())
        .testEquals();
  }

  @Test
  public void testReadBsdTarFormatUstar() throws Exception {
    // $ tar --version
    // bsdtar 2.8.3 - libarchive 2.8.3

    // echo no rain can wash away my tears >liketears
    // echo no wind can soothe my pain >inrain
    // chmod 0600 liketears inrain
    // tar --format=ustar -c liketears inrain | gzip | base64
    InputStream input = new GZIPInputStream(new ByteArrayInputStream(base64().decode(""
        + "H4sIAIl5DVIAA+3T0QqCMBTGca97ivMIx03n84waaNkMNcS3T4OCbuymFcH/dzc22Dd2vrY5hTH"
        + "4fsjSUVWnKllZ5MY5Wde6rvXBVpIbo9ZUpnKFaG7VlZlowkxP12H0/RLl6Ptx69xUh9Bu7L8+Sj"
        + "4bMp3YSe+bKHsfZfJDLX7ys5xnuQ/F7tfxkFgT1+9Pe8f7/ttn/12hS/+NLSr6/w1L/6cmHu79H"
        + "7purMNa/ssyE3QfAAAAAAAAAAAAAADgH9wAqAJg4gAoAAA=")));

    PosixTarHeader header;
    byte[] block = new byte[512];
    String likeTears = "no rain can wash away my tears\n";
    String inRain = "no wind can soothe my pain\n";

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getName()).isEqualTo("liketears");
    assertThat(header.getSize()).isEqualTo(likeTears.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("wheel");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(0);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, likeTears.length())).isEqualTo(likeTears);

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getName()).isEqualTo("inrain");
    assertThat(header.getSize()).isEqualTo(inRain.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("wheel");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(0);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, inRain.length())).isEqualTo(inRain);

    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
  }

  @Test
  public void testReadBsdTarFormatDefault() throws Exception {
    // $ tar --version
    // bsdtar 2.8.3 - libarchive 2.8.3

    // echo no rain can wash away my tears >liketears
    // echo no wind can soothe my pain >inrain
    // chmod 0600 liketears inrain
    // tar -c liketears inrain | gzip | base64
    InputStream input = new GZIPInputStream(new ByteArrayInputStream(base64().decode(""
        + "H4sIAM17DVIAA+3T0QqCMBTGca97ivMIx03n84waaNkMNcS3T4OCbuymFcH/dzc22Dd2vrY5hTH"
        + "4fsjSUVWnKllZ5MY5Wde6rvXBVpIbo9ZUpnKFaG7VlZlowkxP12H0/RLl6Ptx69xUh9Bu7L8+Sj"
        + "4bMp3YSe+bKHsfZfJDLX7ys5xnuQ/F7tfxkFgT1+9Pe8f7/ttn/12hS/+NLSr6/w1L/6cmHu79H"
        + "7purMNa/ssyE3QfAAAAAAAAAAAAAADgH9wAqAJg4gAoAAA=")));

    PosixTarHeader header;
    byte[] block = new byte[512];
    String likeTears = "no rain can wash away my tears\n";
    String inRain = "no wind can soothe my pain\n";

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getName()).isEqualTo("liketears");
    assertThat(header.getSize()).isEqualTo(likeTears.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("wheel");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(0);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, likeTears.length())).isEqualTo(likeTears);

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getName()).isEqualTo("inrain");
    assertThat(header.getSize()).isEqualTo(inRain.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("wheel");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(0);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, inRain.length())).isEqualTo(inRain);

    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
  }

  @Test
  public void testReadGnuTarFormatDefault() throws Exception {
    // $ tar --version
    // tar (GNU tar) 1.26

    // echo no rain can wash away my tears >liketears
    // echo no wind can soothe my pain >inrain
    // chmod 0600 liketears inrain
    // tar -c liketears inrain | gzip | base64
    InputStream input = new GZIPInputStream(new ByteArrayInputStream(base64().decode(""
        + "H4sIAHV8DVIAA+3TTQ6CMBCG4a49xRxhWqCcp1Ei+FMMYIi3t3RhXOkKjMn77Npp0klmvkt3bqY"
        + "mDKNZjyZe1WhVWud9Olvrreb7rKiNdU4LV3tblSaVnVcjumJPL/dxCoOIOYVh+vSuicct2tla7G"
        + "UIXZR9iDKHsZUwh4dcH5KXYvfr9rCyLi7jX/eP7/kv3vKf6larqiD/W0j5n7t4yPkf+35qmyX8t"
        + "7QTZB8AAAAAAAAAAAAAAOAfPAE43i9LACgAAA==")));

    PosixTarHeader header;
    byte[] block = new byte[512];
    String likeTears = "no rain can wash away my tears\n";
    String inRain = "no wind can soothe my pain\n";

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getName()).isEqualTo("liketears");
    assertThat(header.getSize()).isEqualTo(likeTears.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("eng");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(5000);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, likeTears.length())).isEqualTo(likeTears);

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getName()).isEqualTo("inrain");
    assertThat(header.getSize()).isEqualTo(inRain.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("eng");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(5000);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, inRain.length())).isEqualTo(inRain);

    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
  }

  @Test
  public void testReadGnuTarFormatUstar() throws Exception {
    // $ tar --version
    // tar (GNU tar) 1.26

    // echo no rain can wash away my tears >liketears
    // echo no wind can soothe my pain >inrain
    // chmod 0600 liketears inrain
    // tar --format=ustar -c liketears inrain | gzip | base64
    InputStream input = new GZIPInputStream(new ByteArrayInputStream(base64().decode(""
        + "H4sIAOB8DVIAA+3TTQ6DIBCGYdY9BUcYUPE8pDWV/mCjNsbbF01jurIr25i8z4ZACAxhvlu4Vn3"
        + "l205tRxInoqTIjXUuzY1xRub1WVYqY61ktnSmyJUYWzhRWjasafHset+mUi6+7df2VfG8es77Kc"
        + "u4E7HRrQ9RH33Ug+9q7Qc/6vuo56Y4/Ls8bCzE6fu3veN7/rOP/Lsp/1Jk5P8XUv6HEE9z/rum6"
        + "etqCv8j9QTZBwAAAAAAAAAAAAAA2IMXm3pYMgAoAAA=")));

    PosixTarHeader header;
    byte[] block = new byte[512];
    String likeTears = "no rain can wash away my tears\n";
    String inRain = "no wind can soothe my pain\n";

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getType()).isEqualTo(PosixTarHeader.Type.REGULAR);
    assertThat(header.getName()).isEqualTo("liketears");
    assertThat(header.getSize()).isEqualTo(likeTears.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("eng");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(5000);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, likeTears.length())).isEqualTo(likeTears);

    assertThat(input.read(block)).isEqualTo(512);
    header = PosixTarHeader.from(block);
    assertThat(header.getType()).isEqualTo(PosixTarHeader.Type.REGULAR);
    assertThat(header.getName()).isEqualTo("inrain");
    assertThat(header.getSize()).isEqualTo(inRain.length());
    assertThat(header.getMode()).isEqualTo(0600);
    assertThat(header.getUname()).isEqualTo("jart");
    assertThat(header.getGname()).isEqualTo("eng");
    assertThat(header.getUid()).isEqualTo(180918);
    assertThat(header.getGid()).isEqualTo(5000);
    assertThat(header.getMtime().toString(ISODateTimeFormat.date())).isEqualTo("2013-08-16");

    assertThat(input.read(block)).isEqualTo(512);
    assertThat(new String(block, 0, inRain.length())).isEqualTo(inRain);

    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
    assertThat(input.read(block)).isEqualTo(512);
    assertWithMessage("End of archive marker corrupt").that(block).isEqualTo(new byte[512]);
  }
}