com.jingtum.core.bouncycastle.asn1.ConstructedOctetStream Maven / Gradle / Ivy

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/*
 * Copyright www.jingtum.com Inc. 
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.jingtum.core.bouncycastle.asn1;

import java.io.IOException;
import java.io.InputStream;

class ConstructedOctetStream
    extends InputStream
{
    private final ASN1StreamParser _parser;

    private boolean                _first = true;
    private InputStream            _currentStream;

    ConstructedOctetStream(
        ASN1StreamParser parser)
    {
        _parser = parser;
    }

    public int read(byte[] b, int off, int len) throws IOException
    {
        if (_currentStream == null)
        {
            if (!_first)
            {
                return -1;
            }

            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();

            if (s == null)
            {
                return -1;
            }

            _first = false;
            _currentStream = s.getOctetStream();
        }

        int totalRead = 0;

        for (;;)
        {
            int numRead = _currentStream.read(b, off + totalRead, len - totalRead);

            if (numRead >= 0)
            {
                totalRead += numRead;

                if (totalRead == len)
                {
                    return totalRead;
                }
            }
            else
            {
                ASN1OctetStringParser aos = (ASN1OctetStringParser)_parser.readObject();

                if (aos == null)
                {
                    _currentStream = null;
                    return totalRead < 1 ? -1 : totalRead;
                }

                _currentStream = aos.getOctetStream();
            }
        }
    }

    public int read()
        throws IOException
    {
        if (_currentStream == null)
        {
            if (!_first)
            {
                return -1;
            }

            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
    
            if (s == null)
            {
                return -1;
            }
    
            _first = false;
            _currentStream = s.getOctetStream();
        }

        for (;;)
        {
            int b = _currentStream.read();

            if (b >= 0)
            {
                return b;
            }

            ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();

            if (s == null)
            {
                _currentStream = null;
                return -1;
            }

            _currentStream = s.getOctetStream();
        }
    }
}