org.bouncycastle.bcpg.ArmoredInputStream Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcpg-fips Show documentation
Show all versions of bcpg-fips Show documentation
The Bouncy Castle Java APIs for the OpenPGP Protocol. The APIs are designed primarily to be used in conjunction with the BC FIPS provider. The APIs may also be used with other providers although if being used in a FIPS context it is the responsibility of the user to ensure that any other providers used are FIPS certified and used appropriately.
package org.bouncycastle.bcpg;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Vector;
import org.bouncycastle.util.StringList;
import org.bouncycastle.util.Strings;
/**
* reader for Base64 armored objects - read the headers and then start returning
* bytes when the data is reached. An IOException is thrown if the CRC check
* fails.
*/
public class ArmoredInputStream
extends InputStream
{
/*
* set up the decoding table.
*/
private static final byte[] decodingTable;
static
{
decodingTable = new byte[128];
for (int i = 'A'; i <= 'Z'; i++)
{
decodingTable[i] = (byte)(i - 'A');
}
for (int i = 'a'; i <= 'z'; i++)
{
decodingTable[i] = (byte)(i - 'a' + 26);
}
for (int i = '0'; i <= '9'; i++)
{
decodingTable[i] = (byte)(i - '0' + 52);
}
decodingTable['+'] = 62;
decodingTable['/'] = 63;
}
/**
* decode the base 64 encoded input data.
*
* @return the offset the data starts in out.
*/
private int decode(
int in0,
int in1,
int in2,
int in3,
int[] out)
throws EOFException
{
int b1, b2, b3, b4;
if (in3 < 0)
{
throw new EOFException("unexpected end of file in armored stream.");
}
if (in2 == '=')
{
b1 = decodingTable[in0] &0xff;
b2 = decodingTable[in1] & 0xff;
out[2] = ((b1 << 2) | (b2 >> 4)) & 0xff;
return 2;
}
else if (in3 == '=')
{
b1 = decodingTable[in0];
b2 = decodingTable[in1];
b3 = decodingTable[in2];
out[1] = ((b1 << 2) | (b2 >> 4)) & 0xff;
out[2] = ((b2 << 4) | (b3 >> 2)) & 0xff;
return 1;
}
else
{
b1 = decodingTable[in0];
b2 = decodingTable[in1];
b3 = decodingTable[in2];
b4 = decodingTable[in3];
out[0] = ((b1 << 2) | (b2 >> 4)) & 0xff;
out[1] = ((b2 << 4) | (b3 >> 2)) & 0xff;
out[2] = ((b3 << 6) | b4) & 0xff;
return 0;
}
}
InputStream in;
boolean start = true;
int[] outBuf = new int[3];
int bufPtr = 3;
CRC24 crc = new CRC24();
boolean crcFound = false;
boolean hasHeaders = true;
String header = null;
boolean newLineFound = false;
boolean clearText = false;
boolean restart = false;
StringList headerList= Strings.newList();
int lastC = 0;
boolean isEndOfStream;
/**
* Create a stream for reading a PGP armoured message, parsing up to a header
* and then reading the data that follows.
*
* @param in
*/
public ArmoredInputStream(
InputStream in)
throws IOException
{
this(in, true);
}
/**
* Create an armoured input stream which will assume the data starts
* straight away, or parse for headers first depending on the value of
* hasHeaders.
*
* @param in
* @param hasHeaders true if headers are to be looked for, false otherwise.
*/
public ArmoredInputStream(
InputStream in,
boolean hasHeaders)
throws IOException
{
this.in = in;
this.hasHeaders = hasHeaders;
if (hasHeaders)
{
parseHeaders();
}
start = false;
}
public int available()
throws IOException
{
return in.available();
}
private boolean parseHeaders()
throws IOException
{
header = null;
int c;
int last = 0;
boolean headerFound = false;
headerList = Strings.newList();
//
// if restart we already have a header
//
if (restart)
{
headerFound = true;
}
else
{
while ((c = in.read()) >= 0)
{
if (c == '-' && (last == 0 || last == '\n' || last == '\r'))
{
headerFound = true;
break;
}
last = c;
}
}
if (headerFound)
{
StringBuffer buf = new StringBuffer("-");
boolean eolReached = false;
boolean crLf = false;
if (restart) // we've had to look ahead two '-'
{
buf.append('-');
}
while ((c = in.read()) >= 0)
{
if (last == '\r' && c == '\n')
{
crLf = true;
}
if (eolReached && (last != '\r' && c == '\n'))
{
break;
}
if (eolReached && c == '\r')
{
break;
}
if (c == '\r' || (last != '\r' && c == '\n'))
{
String line = buf.toString();
if (line.trim().length() == 0)
{
break;
}
headerList.add(line);
buf.setLength(0);
}
if (c != '\n' && c != '\r')
{
buf.append((char)c);
eolReached = false;
}
else
{
if (c == '\r' || (last != '\r' && c == '\n'))
{
eolReached = true;
}
}
last = c;
}
if (crLf)
{
in.read(); // skip last \n
}
}
if (headerList.size() > 0)
{
header = headerList.get(0);
}
clearText = "-----BEGIN PGP SIGNED MESSAGE-----".equals(header);
newLineFound = true;
return headerFound;
}
/**
* @return true if we are inside the clear text section of a PGP
* signed message.
*/
public boolean isClearText()
{
return clearText;
}
/**
* @return true if the stream is actually at end of file.
*/
public boolean isEndOfStream()
{
return isEndOfStream;
}
/**
* Return the armor header line (if there is one)
* @return the armor header line, null if none present.
*/
public String getArmorHeaderLine()
{
return header;
}
/**
* Return the armor headers (the lines after the armor header line),
* @return an array of armor headers, null if there aren't any.
*/
public String[] getArmorHeaders()
{
if (headerList.size() <= 1)
{
return null;
}
return headerList.toStringArray(1, headerList.size());
}
private int readIgnoreSpace()
throws IOException
{
int c = in.read();
while (c == ' ' || c == '\t')
{
c = in.read();
}
return c;
}
public int read()
throws IOException
{
int c;
if (start)
{
if (hasHeaders)
{
parseHeaders();
}
crc.reset();
start = false;
}
if (clearText)
{
c = in.read();
if (c == '\r' || (c == '\n' && lastC != '\r'))
{
newLineFound = true;
}
else if (newLineFound && c == '-')
{
c = in.read();
if (c == '-') // a header, not dash escaped
{
clearText = false;
start = true;
restart = true;
}
else // a space - must be a dash escape
{
c = in.read();
}
newLineFound = false;
}
else
{
if (c != '\n' && lastC != '\r')
{
newLineFound = false;
}
}
lastC = c;
if (c < 0)
{
isEndOfStream = true;
}
return c;
}
if (bufPtr > 2 || crcFound)
{
c = readIgnoreSpace();
if (c == '\r' || c == '\n')
{
c = readIgnoreSpace();
while (c == '\n' || c == '\r')
{
c = readIgnoreSpace();
}
if (c < 0) // EOF
{
isEndOfStream = true;
return -1;
}
if (c == '=') // crc reached
{
bufPtr = decode(readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), outBuf);
if (bufPtr == 0)
{
int i = ((outBuf[0] & 0xff) << 16)
| ((outBuf[1] & 0xff) << 8)
| (outBuf[2] & 0xff);
crcFound = true;
if (i != crc.getValue())
{
throw new IOException("crc check failed in armored message.");
}
return read();
}
else
{
throw new IOException("no crc found in armored message.");
}
}
else if (c == '-') // end of record reached
{
while ((c = in.read()) >= 0)
{
if (c == '\n' || c == '\r')
{
break;
}
}
if (!crcFound)
{
throw new IOException("crc check not found.");
}
crcFound = false;
start = true;
bufPtr = 3;
if (c < 0)
{
isEndOfStream = true;
}
return -1;
}
else // data
{
bufPtr = decode(c, readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), outBuf);
}
}
else
{
if (c >= 0)
{
bufPtr = decode(c, readIgnoreSpace(), readIgnoreSpace(), readIgnoreSpace(), outBuf);
}
else
{
isEndOfStream = true;
return -1;
}
}
}
c = outBuf[bufPtr++];
crc.update(c);
return c;
}
public void close()
throws IOException
{
in.close();
}
}