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      1 /*
      2  *  Licensed to the Apache Software Foundation (ASF) under one or more
      3  *  contributor license agreements.  See the NOTICE file distributed with
      4  *  this work for additional information regarding copyright ownership.
      5  *  The ASF licenses this file to You under the Apache License, Version 2.0
      6  *  (the "License"); you may not use this file except in compliance with
      7  *  the License.  You may obtain a copy of the License at
      8  *
      9  *     http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  */
     17 
     18 package org.apache.harmony.xnet.provider.jsse;
     19 
     20 import java.io.IOException;
     21 import java.io.InputStream;
     22 
     23 /**
     24  * This class is a base for all input stream classes used
     25  * in protocol implementation. It extends an InputStream with
     26  * some additional read methods allowing to read TLS specific
     27  * data types such as uint8, uint32 etc (see TLS v 1 specification
     28  * at http://www.ietf.org/rfc/rfc2246.txt).
     29  */
     30 public abstract class SSLInputStream extends InputStream {
     31 
     32     @Override
     33     public abstract int available() throws IOException;
     34 
     35     /**
     36      * Reads the following byte value. Note that in the case of
     37      * reaching of the end of the data this methods throws the
     38      * exception, not return -1. The type of exception depends
     39      * on implementation. It was done for simplifying and speeding
     40      * up of processing of such cases.
     41      * @see org.apache.harmony.xnet.provider.jsse.SSLStreamedInput#read()
     42      * @see org.apache.harmony.xnet.provider.jsse.SSLBufferedInput#read()
     43      * @see org.apache.harmony.xnet.provider.jsse.HandshakeIODataStream#read()
     44      */
     45     @Override
     46     public abstract int read() throws IOException;
     47 
     48     /**
     49      * Reads and returns uint8 value.
     50      */
     51     public int readUint8() throws IOException {
     52         return read() & 0x00FF;
     53     }
     54 
     55     /**
     56      * Reads and returns uint16 value.
     57      */
     58     public int readUint16() throws IOException {
     59         return (read() << 8) | (read() & 0x00FF);
     60     }
     61 
     62     /**
     63      * Reads and returns uint24 value.
     64      */
     65     public int readUint24() throws IOException {
     66         return (read() << 16) | (read() << 8) | (read() & 0x00FF);
     67     }
     68 
     69     /**
     70      * Reads and returns uint32 value.
     71      */
     72     public long readUint32() throws IOException {
     73         return (read() << 24) | (read() << 16)
     74               | (read() << 8) | (read() & 0x00FF);
     75     }
     76 
     77     /**
     78      * Reads and returns uint64 value.
     79      */
     80     public long readUint64() throws IOException {
     81         long hi = readUint32();
     82         long lo = readUint32();
     83         return (hi << 32) | lo;
     84     }
     85 
     86     /**
     87      * Returns the vector of opaque values of specified length;
     88      * @param length - the length of the vector to be read.
     89      * @return the read data
     90      * @throws IOException if read operation could not be finished.
     91      */
     92     public byte[] read(int length) throws IOException {
     93         byte[] res = new byte[length];
     94         for (int i=0; i<length; i++) {
     95             res[i] = (byte) read();
     96         }
     97         return res;
     98     }
     99 
    100     @Override
    101     public int read(byte[] b, int off, int len) throws IOException {
    102         int read_b;
    103         int i = 0;
    104         do {
    105             if ((read_b = read()) == -1) {
    106                 return (i == 0) ? -1 : i;
    107             }
    108             b[off+i] = (byte) read_b;
    109             i++;
    110         } while ((available() != 0) && (i<len));
    111         return i;
    112     }
    113 }
    114