protocols/ldap/ASN1ReaderTestCase.java

	ASN1ReaderTestCase.java revision ea1068c292e9b341af6d6b563cd8988a96be20a9
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
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 *
 *
 *      Copyright 2006-2009 Sun Microsystems, Inc.
 *      Portions Copyright 2014-2015 ForgeRock AS
 */
package org.opends.server.protocols.ldap;

import java.io.IOException;

import org.forgerock.opendj.io.ASN1;
import org.forgerock.opendj.io.ASN1Reader;
import org.forgerock.opendj.ldap.ByteString;
import org.forgerock.opendj.ldap.ByteStringBuilder;
import org.forgerock.opendj.ldap.DecodeException;
import org.opends.server.DirectoryServerTestCase;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import static org.testng.Assert.*;

/**
 * An abstract base class for all ASN1Reader test cases.
 */
@Test(groups = { "precommit", "asn1" }, sequential = true)
public abstract class ASN1ReaderTestCase extends DirectoryServerTestCase
{

  /**
   * Retrieves the set of byte array values that may be used for testing.
   *
   * @return  The set of byte array values that may be used for testing.
   */
  @DataProvider(name = "byteValues")
  public Object[][] getByteValues()
  {
    Object[][] array = new Object[256][1];
    for (int i=0; i < 256; i++)
    {
      array[i] = new Object[] { new byte[] { (byte) (i & 0xFF) } };
    }

    return array;
  }


  /**
   * Create byte arrays with encoded ASN.1 elements to test decoding them as
   * octet strings.
   *
   * @return  A list of byte arrays with encoded ASN.1 elements that can be
   *          decoded as octet strings.
   */
  @DataProvider(name = "elementArrays")
  public Object[][] getElementArrays()
  {
    return new Object[][]
        {
            new Object[] { new byte[] { 0x04, 0x00 } },
            new Object[] { new byte[] { (byte) 0x50, 0x00 } },
            new Object[] { new byte[] { 0x04, 0x05, 0x48, 0x65, 0x6C, 0x6C, 0x6F } },
            new Object[] { new byte[] { 0x01, 0x01, 0x00 } },
            new Object[] { new byte[] { 0x01, 0x01, (byte) 0xFF } },
            new Object[] { new byte[] { 0x0A, 0x01, 0x00 } },
            new Object[] { new byte[] { 0x0A, 0x01, 0x01 } },
            new Object[] { new byte[] { 0x0A, 0x01, 0x7F } },
            new Object[] { new byte[] { 0x0A, 0x01, (byte) 0x80 } },
            new Object[] { new byte[] { 0x0A, 0x01, (byte) 0xFF } },
            new Object[] { new byte[] { 0x0A, 0x02, 0x01, 0x00 } },
            new Object[] { new byte[] { 0x02, 0x01, 0x00 } },
            new Object[] { new byte[] { 0x02, 0x01, 0x01 } },
            new Object[] { new byte[] { 0x02, 0x01, 0x7F } },
            new Object[] { new byte[] { 0x02, 0x02, 0x00, (byte) 0x80 } },
            new Object[] { new byte[] { 0x02, 0x02, 0x00, (byte) 0xFF } },
            new Object[] { new byte[] { 0x02, 0x02, 0x01, 0x00 } },
            new Object[] { new byte[] { 0x05, 0x00 } },
            new Object[] { new byte[] { 0x30, 0x00 } },
            new Object[] { new byte[] { 0x31, 0x00 } },
            new Object[] { new byte[] { 0x05, (byte) 0x81, 0x00 } },
            new Object[] { new byte[] { 0x05, (byte) 0x82, 0x00, 0x00 } },
            new Object[] { new byte[] { 0x05, (byte) 0x83, 0x00, 0x00, 0x00 } },
            new Object[] { new byte[] { 0x05, (byte) 0x84, 0x00, 0x00, 0x00, 0x00 } },
        };
  }

  /**
   * Gets the reader to be use for the unit tests.
   *
   * @param b
   *          The array of bytes to be read.
   * @param maxElementSize
   *          The max element size.
   * @return The reader to be use for the unit tests.
   * @throws IOException
   *           In an unexpected IO exception occurred.
   */
  abstract ASN1Reader getReader(byte[] b, int maxElementSize)
      throws IOException;

  /**
   * Tests the <CODE>decodeAsNull</CODE> method that takes a byte array argument
   * with a short array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeShortArrayAsNull()
      throws Exception
  {
    byte[] b = new byte[1];
    getReader(b, 0).readNull();
  }


  /**
   * Tests the <CODE>decodeAsNull</CODE> method that takes a byte array argument
   * with an array with a long length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLongLengthArrayAsNull()
      throws Exception
  {
    byte[] b = new byte[] { 0x05, (byte) 0x85, 0x00, 0x00, 0x00, 0x00, 0x00 };
    getReader(b, 0).readNull();
  }


  /**
   * Tests the <CODE>decodeAsNull</CODE> method that takes a byte array argument
   * with an array with a truncated length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeTruncatedLengthArrayAsNull()
      throws Exception
  {
    byte[] b = new byte[] { 0x05, (byte) 0x82, 0x00 };
    getReader(b, 0).readNull();
  }


  /**
   * Tests the <CODE>decodeAsNull</CODE> method that takes a byte array argument
   * with an arry with a nonzero length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeNonZeroLengthArrayAsNull()
      throws Exception
  {
    byte[] b = new byte[] { 0x05, 0x01, 0x00 };
    getReader(b, 0).readNull();
  }


  /**
   * Tests the <CODE>decodeAsNull</CODE> method that takes a byte array argument
   * with an arry with a zero length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test
  public void testDecodeZeroLengthArrayAsNull()
      throws Exception
  {
    byte[] b = new byte[] { 0x05, 0x00 };
    getReader(b, 0).readNull();
  }


  /**
   * Tests the <CODE>decodeAsNull</CODE> method that takes a byte array argument
   * with an arry with a zero length that takes multiple bytes to encode.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test
  public void testDecodeExtendedZeroLengthArrayAsNull()
      throws Exception
  {
    byte[] b = new byte[] { 0x05, (byte) 0x81, 0x00 };
    getReader(b, 0).readNull();
  }

  /**
   * Tests the <CODE>decodeAsInteger</CODE> method that takes a byte array with
   * a short array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeShortArrayAsInteger()
      throws Exception
  {
    byte[] b = new byte[0];
    getReader(b, 0).readInteger();
  }

  /**
   * Tests the <CODE>readEnumerated</CODE> method that takes a byte array with
   * a short array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeShortArrayAsEnumerated()
      throws Exception
  {
    byte[] b = new byte[0];
    getReader(b, 0).readEnumerated();
  }


  /**
   * Tests the <CODE>decodeAsInteger</CODE> method that takes a byte array with
   * a long length array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLongLengthArrayAsInteger()
      throws Exception
  {
    byte[] b = { 0x02, (byte) 0x85, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00 };
    getReader(b, 0).readInteger();
  }


  /**
   * Tests the <CODE>readEnumerated</CODE> method that takes a byte array with
   * a long length array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLongLengthArrayAsEnumerated()
      throws Exception
  {
    byte[] b = { 0x02, (byte) 0x85, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00 };
    getReader(b, 0).readEnumerated();
  }


  /**
   * Tests the <CODE>decodeAsInteger</CODE> method that takes a byte array with
   * a truncated length array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeTruncatedLengthArrayAsInteger()
      throws Exception
  {
    byte[] b = { 0x02, (byte) 0x82, 0x00 };
    getReader(b, 0).readInteger();
  }


  /**
   * Tests the <CODE>readEnumerated</CODE> method that takes a byte array with
   * a truncated length array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeTruncatedLengthArrayAsEnumerated()
      throws Exception
  {
    byte[] b = { 0x02, (byte) 0x82, 0x00 };
    getReader(b, 0).readEnumerated();
  }


  /**
   * Tests the <CODE>decodeAsInteger</CODE> method that takes a byte array with
   * a length mismatch.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLengthMismatchArrayAsInteger()
      throws Exception
  {
    byte[] b = { 0x02, (byte) 0x81, 0x01 };
    getReader(b, 0).readInteger();
  }

  /**
   * Tests the <CODE>readEnumerated</CODE> method that takes a byte array with
   * a length mismatch.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLengthMismatchArrayAsEnumerated()
      throws Exception
  {
    byte[] b = { 0x02, (byte) 0x81, 0x01 };
    getReader(b, 0).readEnumerated();
  }

  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with valid arrays.
   *
   * @param  b  The byte array to use for the element values.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(dataProvider = "byteValues")
  public void testDecodeValidArrayAsBoolean(byte[] b)
      throws Exception
  {
    // First, test with the standard Boolean type.
    byte[] elementArray = new byte[] { 0x01, 0x01, b[0] };
    assertEquals(getReader(elementArray, 0).readBoolean(), (b[0] != 0x00));


    // Next, test with a nonstandard Boolean type.
    elementArray[0] = (byte) 0x50;
    assertEquals(getReader(elementArray, 0).readBoolean(), (b[0] != 0x00));
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with valid arrays using extended lengths.
   *
   * @param  b  The byte array to use for the element values.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(dataProvider = "byteValues")
  public void testDecodeValidExtendedArrayAsBoolean(byte[] b)
      throws Exception
  {
    // First, test with the standard Boolean type.
    byte[] elementArray = new byte[] { 0x01, (byte) 0x81, 0x01, b[0] };
    assertEquals(getReader(elementArray, 0).readBoolean(), (b[0] != 0x00));


    // Next, test with a nonstandard Boolean type.
    elementArray[0] = (byte) 0x50;
    assertEquals(getReader(elementArray, 0).readBoolean(), (b[0] != 0x00));
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with a short array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeShortArrayAsBoolean()
      throws Exception
  {
    byte[] b = new byte[1];
    getReader(b, 0).readBoolean();
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with an array that takes too many bytes to expressthe length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLongLengthArrayAsBoolean()
      throws Exception
  {
    byte[] b = { 0x01, (byte) 0x85, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00 };
    getReader(b, 0).readBoolean();
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with an array that doesn't contain a full length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeTruncatedLengthArrayAsBoolean()
      throws Exception
  {
    byte[] b = { 0x01, (byte) 0x82, 0x00 };
    getReader(b, 0).readBoolean();
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with an array that has less bytes than indicated by the length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLengthMismatchArrayAsBoolean()
      throws Exception
  {
    byte[] b = { 0x01, 0x01 };
    getReader(b, 0).readBoolean();
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with an array that has an invalid number of bytes in the value.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeShortValueArrayAsBoolean()
      throws Exception
  {
    byte[] b = { 0x01, 0x00, 0x00, 0x00 };
    getReader(b, 0).readBoolean();
  }


  /**
   * Tests the <CODE>decodeAsBoolean</CODE> method that takes a byte array
   * argument with an array that has an invalid number of bytes in the value.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLongValueArrayAsBoolean()
      throws Exception
  {
    byte[] b = { 0x01, 0x02, 0x00, 0x00 };
    getReader(b, 0).readBoolean();
  }


  /**
   * Tests the <CODE>decodeAsOctetString</CODE> method that takes a byte array
   * using a valid array.
   *
   * @param  b  The byte array to decode.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(dataProvider = "elementArrays")
  public void testDecodeValidArrayAsOctetString(byte[] b)
      throws Exception
  {
    ByteStringBuilder bsb = new ByteStringBuilder();
    bsb.append(ASN1.UNIVERSAL_OCTET_STRING_TYPE);
    bsb.appendBERLength(b.length);
    bsb.append(b);

    assertEquals(getReader(bsb.toByteArray(), 0).readOctetString(),
        ByteString.wrap(b));
  }

  /**
   * Tests the <CODE>decodeAsOctetStringAsString</CODE> method that takes a
   * byte array using a valid array.
   *
   * @param  b  The byte array to decode.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(dataProvider = "elementArrays")
  public void testDecodeValidArrayAsOctetStringAsString(byte[] b)
      throws Exception
  {
    ByteStringBuilder bsb = new ByteStringBuilder();
    bsb.append(ASN1.UNIVERSAL_OCTET_STRING_TYPE);
    bsb.appendBERLength(b.length);
    bsb.append(b);

    assertEquals(getReader(bsb.toByteArray(), 0).readOctetStringAsString(),
        new String(b, "UTF-8"));
  }

  /**
   * Tests the <CODE>decodeAsOctetStringBuilder</CODE> method that takes a
   * byte array using a valid array.
   *
   * @param  b  The byte array to decode.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(dataProvider = "elementArrays")
  public void testDecodeValidArrayAsOctetStringBuilder(byte[] b)
      throws Exception
  {
    ByteStringBuilder bsb = new ByteStringBuilder();
    bsb.append(ASN1.UNIVERSAL_OCTET_STRING_TYPE);
    bsb.appendBERLength(b.length);
    bsb.append(b);

    ByteStringBuilder bsb2 = new ByteStringBuilder();
    getReader(bsb.toByteArray(), 0).readOctetString(bsb2);
    assertEquals(bsb2.toByteString(), ByteString.wrap(b));
  }


  /**
   * Tests the <CODE>decodeAsOctetString</CODE> method that takes a byte array
   * using a short array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions  = { DecodeException.class })
  public void testDecodeShortArrayAsOctetString()
      throws Exception
  {
    byte[] b = new byte[1];
    getReader(b, 0).readOctetString();
  }


  /**
   * Tests the <CODE>decodeAsOctetString</CODE> method that takes a byte array
   * using an array that indicates it takes more than four bytes to encode the
   * length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions  = { DecodeException.class })
  public void testDecodeLongLengthArrayAsOctetString()
      throws Exception
  {
    byte[] b = { 0x04, (byte) 0x85, 0x00, 0x00, 0x00, 0x00, 0x00 };
    getReader(b, 0).readOctetString();
  }


  /**
   * Tests the <CODE>decodeAsOctetString</CODE> method that takes a byte array
   * using an array that doesn't fully contain the length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions  = { DecodeException.class })
  public void testDecodeTruncatedLengthArrayAsOctetString()
      throws Exception
  {
    byte[] b = { 0x04, (byte) 0x82, 0x00 };
    getReader(b, 0).readOctetString();
  }


  /**
   * Tests the <CODE>decodeAsOctetString</CODE> method that takes a byte array
   * using an array whose actual length doesn't match with the decoded length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions  = { DecodeException.class })
  public void testDecodeLengthMismatchArrayAsOctetString()
      throws Exception
  {
    byte[] b = { 0x04, 0x02, 0x00 };
    getReader(b, 0).readOctetString();
  }

  /**
   * Tests the <CODE>decodeAsSequence</CODE> method that takes a byte array
   * argument with valid arrays.
   *
   * @param  encodedElements  Byte arrays that may be used as valid values for
   *                          encoded elements.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(dataProvider = "elementArrays")
  public void testDecodeValidArrayAsSequence(byte[] encodedElements)
      throws Exception
  {
    ByteStringBuilder bsb = new ByteStringBuilder();
    bsb.append(ASN1.UNIVERSAL_SEQUENCE_TYPE);
    bsb.appendBERLength(encodedElements.length + 2);
    bsb.append(ASN1.UNIVERSAL_OCTET_STRING_TYPE);
    bsb.appendBERLength(encodedElements.length);
    bsb.append(encodedElements);

    ASN1Reader reader = getReader(bsb.toByteArray(), 0);
    assertEquals(reader.peekLength(), encodedElements.length + 2);
    reader.readStartSequence();
    assertEquals(reader.peekType(), ASN1.UNIVERSAL_OCTET_STRING_TYPE);
    assertEquals(reader.peekLength(), encodedElements.length);
    reader.readOctetString().equals(ByteString.wrap(encodedElements));
    reader.readEndSequence();
  }


  /**
   * Tests the <CODE>decodeAsSequence</CODE> method that takes a byte array
   * argument with a short array.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeShortArrayAsSequence()
      throws Exception
  {
    byte[] b = new byte[1];
    getReader(b, 0).readStartSequence();
  }


  /**
   * Tests the <CODE>decodeAsSequence</CODE> method that takes a byte array
   * argument with an array that takes too many bytes to encode the length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeLongLengthArrayAsSequence()
      throws Exception
  {
    byte[] b = { 0x30, (byte) 0x85, 0x00, 0x00, 0x00, 0x00, 0x00 };
    getReader(b, 0).readStartSequence();
  }


  /**
   * Tests the <CODE>decodeAsSequence</CODE> method that takes a byte array
   * argument with an array that doesn't fully describe the length.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeTruncatedLengthArrayAsSequence()
      throws Exception
  {
    byte[] b = { 0x30, (byte) 0x82, 0x00 };
    getReader(b, 0).readStartSequence();
  }


  /**
   * Tests the <CODE>readOctetString</CODE> method when the max element size
   * is exceeded.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeOctetStringExceedMaxSize()
      throws Exception
  {
    byte[] b = new byte[] { 0x04, 0x05, 0x48, 0x65, 0x6C, 0x6C, 0x6F };
    getReader(b, 3).readOctetString();
  }

  /**
   * Tests the <CODE>readOctetString</CODE> method when the max element size
   * is exceeded.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeSequenceExceedMaxSize()
      throws Exception
  {
    byte[] b = new byte[] { 0x30, 0x07, 0x04, 0x05, 0x48, 0x65, 0x6C, 0x6C, 0x6F };
    getReader(b, 3).readOctetString();
  }

  /**
   * Tests to make sure a premature EOF while reading a sub sequence can be
   * detected.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testDecodeSequencePrematureEof()
      throws Exception
  {
    // An ASN.1 sequence of booleans missing one boolean element at the end
    byte[] b = new byte[] { 0x30, 0x09, 0x01, 0x01, 0x00, 0x01, 0x01, 0x00 };
    ASN1Reader reader = getReader(b, 0);
    reader.readStartSequence();
    while(reader.hasNextElement())
    {
      reader.readBoolean();
    }
    reader.readEndSequence();
  }

  /**
   * Tests to make sure trailing components are ignored if not used.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test
  public void testDecodeSequenceIncompleteRead()
      throws Exception
  {
    // An ASN.1 sequence of booleans missing one boolean element at the end
    byte[] b = new byte[] { 0x30, 0x06, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00 };
    ASN1Reader reader = getReader(b, 0);
    reader.readStartSequence();
    reader.readEndSequence();
    assertFalse(reader.readBoolean());
  }

  /**
   * Tests the <CODE>skipElement</CODE> method.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { DecodeException.class })
  public void testSkipElementIncompleteRead()
      throws Exception
  {
    // An ASN.1 sequence of booleans missing one boolean element at the end
    byte[] b = new byte[] { 0x30, 0x09, 0x01, 0x01, 0x00, 0x01, 0x02 };
    ASN1Reader reader = getReader(b, 0);
    reader.readStartSequence();
    reader.readBoolean();
    reader.skipElement();
    reader.readEndSequence();
  }

  /**
   * Tests the <CODE>skipElement</CODE> method.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test
  public void testSkipElement()
      throws Exception
  {
    // An ASN.1 sequence of booleans missing one boolean element at the end
    byte[] b = new byte[] { 0x30, 0x09, 0x02, 0x01, 0x00, 0x02, 0x01, 0x01,
        0x02, 0x01, 0x02 };
    ASN1Reader reader = getReader(b, 0);
    reader.readStartSequence();
    reader.readInteger();
    reader.skipElement();
    assertEquals(reader.readInteger(), 2);
    reader.readEndSequence();
  }

  /**
   * Tests the <CODE>elementAvailable</CODE> method.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test
  public void testElementAvailable()
      throws Exception
  {
    // An ASN.1 sequence of booleans missing one boolean element at the end
    byte[] b = new byte[] { 0x30, 0x06, 0x02, 0x01, 0x00, 0x02 };
    ASN1Reader reader = getReader(b, 0);
    assertFalse(reader.elementAvailable());

    b = new byte[] { 0x30, 0x03, 0x02, 0x01, 0x00 };
    reader = getReader(b, 0);
    assertTrue(reader.elementAvailable());
    reader.readStartSequence();
    assertTrue(reader.elementAvailable());
    reader.readInteger();
    assertFalse(reader.elementAvailable());
  }

  /**
   * Tests the <CODE>hasNextElement</CODE> method.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test
  public void testHasNextElement()
      throws Exception
  {
    // An ASN.1 sequence of booleans missing one boolean element at the end
    byte[] b = new byte[] { 0x30, 0x06, 0x02, 0x01, 0x00, 0x02, 0x00, 0x03 };
    ASN1Reader reader = getReader(b, 0);
    assertTrue(reader.hasNextElement());
    reader.readStartSequence();
    assertTrue(reader.hasNextElement());
    reader.readInteger();
    assertTrue(reader.hasNextElement());

    b = new byte[] { 0x30, 0x03, 0x02, 0x01, 0x00 };
    reader = getReader(b, 0);
    assertTrue(reader.hasNextElement());
    reader.readStartSequence();
    assertTrue(reader.hasNextElement());
    reader.readInteger();
    assertFalse(reader.hasNextElement());
  }

  /**
   * Tests the <CODE>readEndSequence</CODE> method without first calling
   * readStartSequence.
   *
   * @throws  Exception  If an unexpected problem occurs.
   */
  @Test(expectedExceptions = { IllegalStateException.class })
  public void testReadEndSequenceNoStartSequence() throws Exception
  {
    byte[] b = { 0x30, 0x01, 0x00 };
    getReader(b, 0).readEndSequence();
  }
}