package org.spongycastle.bcpg;
import org.spongycastle.util.io.Streams;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
/**
* reader for PGP objects
*/
public class BCPGInputStream
extends InputStream implements PacketTags
{
InputStream in;
boolean next = false;
int nextB;
public BCPGInputStream(
InputStream in)
{
this.in = in;
}
public int available()
throws IOException
{
return in.available();
}
public int read()
throws IOException
{
if (next)
{
next = false;
return nextB;
}
else
{
return in.read();
}
}
public int read(
byte[] buf,
int off,
int len)
throws IOException
{
if (len == 0)
{
return 0;
}
if (!next)
{
return in.read(buf, off, len);
}
// We have next byte waiting, so return it
if (nextB < 0)
{
return -1; // EOF
}
buf[off] = (byte)nextB; // May throw NullPointerException...
next = false; // ...so only set this afterwards
return 1;
}
public void readFully(
byte[] buf,
int off,
int len)
throws IOException
{
if (Streams.readFully(this, buf, off, len) < len)
{
throw new EOFException();
}
}
public void readFully(
byte[] buf)
throws IOException
{
readFully(buf, 0, buf.length);
}
/**
* returns the next packet tag in the stream.
*
* @return the tag number.
*
* @throws IOException
*/
public int nextPacketTag()
throws IOException
{
if (!next)
{
try
{
nextB = in.read();
}
catch (EOFException e)
{
nextB = -1;
}
}
next = true;
if (nextB >= 0)
{
if ((nextB & 0x40) != 0) // new
{
return (nextB & 0x3f);
}
else // old
{
return ((nextB & 0x3f) >> 2);
}
}
return nextB;
}
public Packet readPacket()
throws IOException
{
int hdr = this.read();
if (hdr < 0)
{
return null;
}
if ((hdr & 0x80) == 0)
{
throw new IOException("invalid header encountered");
}
boolean newPacket = (hdr & 0x40) != 0;
int tag = 0;
int bodyLen = 0;
boolean partial = false;
if (newPacket)
{
tag = hdr & 0x3f;
int l = this.read();
if (l < 192)
{
bodyLen = l;
}
else if (l <= 223)
{
int b = in.read();
bodyLen = ((l - 192) << 8) + (b) + 192;
}
else if (l == 255)
{
bodyLen = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read();
}
else
{
partial = true;
bodyLen = 1 << (l & 0x1f);
}
}
else
{
int lengthType = hdr & 0x3;
tag = (hdr & 0x3f) >> 2;
switch (lengthType)
{
case 0:
bodyLen = this.read();
break;
case 1:
bodyLen = (this.read() << 8) | this.read();
break;
case 2:
bodyLen = (this.read() << 24) | (this.read() << 16) | (this.read() << 8) | this.read();
break;
case 3:
partial = true;
break;
default:
throw new IOException("unknown length type encountered");
}
}
BCPGInputStream objStream;
if (bodyLen == 0 && partial)
{
objStream = this;
}
else
{
objStream = new BCPGInputStream(new PartialInputStream(this, partial, bodyLen));
}
switch (tag)
{
case RESERVED:
return new InputStreamPacket(objStream);
case PUBLIC_KEY_ENC_SESSION:
return new PublicKeyEncSessionPacket(objStream);
case SIGNATURE:
return new SignaturePacket(objStream);
case SYMMETRIC_KEY_ENC_SESSION:
return new SymmetricKeyEncSessionPacket(objStream);
case ONE_PASS_SIGNATURE:
return new OnePassSignaturePacket(objStream);
case SECRET_KEY:
return new SecretKeyPacket(objStream);
case PUBLIC_KEY:
return new PublicKeyPacket(objStream);
case SECRET_SUBKEY:
return new SecretSubkeyPacket(objStream);
case COMPRESSED_DATA:
return new CompressedDataPacket(objStream);
case SYMMETRIC_KEY_ENC:
return new SymmetricEncDataPacket(objStream);
case MARKER:
return new MarkerPacket(objStream);
case LITERAL_DATA:
return new LiteralDataPacket(objStream);
case TRUST:
return new TrustPacket(objStream);
case USER_ID:
return new UserIDPacket(objStream);
case USER_ATTRIBUTE:
return new UserAttributePacket(objStream);
case PUBLIC_SUBKEY:
return new PublicSubkeyPacket(objStream);
case SYM_ENC_INTEGRITY_PRO:
return new SymmetricEncIntegrityPacket(objStream);
case MOD_DETECTION_CODE:
return new ModDetectionCodePacket(objStream);
case EXPERIMENTAL_1:
case EXPERIMENTAL_2:
case EXPERIMENTAL_3:
case EXPERIMENTAL_4:
return new ExperimentalPacket(tag, objStream);
default:
throw new IOException("unknown packet type encountered: " + tag);
}
}
public void close()
throws IOException
{
in.close();
}
/**
* a stream that overlays our input stream, allowing the user to only read a segment of it.
*
* NB: dataLength will be negative if the segment length is in the upper range above 2**31.
*/
private static class PartialInputStream
extends InputStream
{
private BCPGInputStream in;
private boolean partial;
private int dataLength;
PartialInputStream(
BCPGInputStream in,
boolean partial,
int dataLength)
{
this.in = in;
this.partial = partial;
this.dataLength = dataLength;
}
public int available()
throws IOException
{
int avail = in.available();
if (avail <= dataLength || dataLength < 0)
{
return avail;
}
else
{
if (partial && dataLength == 0)
{
return 1;
}
return dataLength;
}
}
private int loadDataLength()
throws IOException
{
int l = in.read();
if (l < 0)
{
return -1;
}
partial = false;
if (l < 192)
{
dataLength = l;
}
else if (l <= 223)
{
dataLength = ((l - 192) << 8) + (in.read()) + 192;
}
else if (l == 255)
{
dataLength = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read();
}
else
{
partial = true;
dataLength = 1 << (l & 0x1f);
}
return dataLength;
}
public int read(byte[] buf, int offset, int len)
throws IOException
{
do
{
if (dataLength != 0)
{
int readLen = (dataLength > len || dataLength < 0) ? len : dataLength;
readLen = in.read(buf, offset, readLen);
if (readLen < 0)
{
throw new EOFException("premature end of stream in PartialInputStream");
}
dataLength -= readLen;
return readLen;
}
}
while (partial && loadDataLength() >= 0);
return -1;
}
public int read()
throws IOException
{
do
{
if (dataLength != 0)
{
int ch = in.read();
if (ch < 0)
{
throw new EOFException("premature end of stream in PartialInputStream");
}
dataLength--;
return ch;
}
}
while (partial && loadDataLength() >= 0);
return -1;
}
}
}