package org.bouncycastle.bcpg;
import java.io.*;
import org.bouncycastle.bcpg.attr.ImageAttribute;
/**
* reader for user attribute sub-packets
*/
public class UserAttributeSubpacketInputStream
extends InputStream implements UserAttributeSubpacketTags
{
InputStream in;
public UserAttributeSubpacketInputStream(
InputStream in)
{
this.in = in;
}
public int available()
throws IOException
{
return in.available();
}
public int read()
throws IOException
{
return in.read();
}
private void readFully(
byte[] buf,
int off,
int len)
throws IOException
{
if (len > 0)
{
int b = this.read();
if (b < 0)
{
throw new EOFException();
}
buf[off] = (byte)b;
off++;
len--;
}
while (len > 0)
{
int l = in.read(buf, off, len);
if (l < 0)
{
throw new EOFException();
}
off += l;
len -= l;
}
}
public UserAttributeSubpacket readPacket()
throws IOException
{
int l = this.read();
int bodyLen = 0;
if (l < 0)
{
return null;
}
if (l < 192)
{
bodyLen = l;
}
else if (l < 223)
{
bodyLen = ((l - 192) << 8) + (in.read()) + 192;
}
else if (l == 255)
{
bodyLen = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read();
}
int tag = in.read();
if (tag < 0)
{
throw new EOFException("unexpected EOF reading user attribute sub packet");
}
byte[] data = new byte[bodyLen - 1];
this.readFully(data, 0, data.length);
int type = tag;
switch (type)
{
case IMAGE_ATTRIBUTE:
return new ImageAttribute(data);
}
return new UserAttributeSubpacket(type, data);
}
}