net.oauth.signature.pem.PEMReader Maven / Gradle / Ivy
/****************************************************************************
* Copyright (c) 1998-2009 AOL LLC.
*
* Licensed 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.
*
****************************************************************************
*
* @author: zhang
* @version: $Revision$
* @created: Apr 24, 2009
*
* Description: A class to decode PEM files
*
****************************************************************************/
package net.oauth.signature.pem;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import net.oauth.signature.OAuthSignatureMethod;
/**
* This class convert PEM into byte array. The begin marker
* is saved and it can be used to determine the type of the
* PEM file.
*
* @author zhang
*/
public class PEMReader {
// Begin markers for all supported PEM files
public static final String PRIVATE_PKCS1_MARKER =
"-----BEGIN RSA PRIVATE KEY-----";
public static final String PRIVATE_PKCS8_MARKER =
"-----BEGIN PRIVATE KEY-----";
public static final String CERTIFICATE_X509_MARKER =
"-----BEGIN CERTIFICATE-----";
public static final String PUBLIC_X509_MARKER =
"-----BEGIN PUBLIC KEY-----";
private static final String BEGIN_MARKER = "-----BEGIN ";
private InputStream stream;
private byte[] derBytes;
private String beginMarker;
public PEMReader(InputStream inStream) throws IOException {
stream = inStream;
readFile();
}
public PEMReader(byte[] buffer) throws IOException {
this(new ByteArrayInputStream(buffer));
}
public PEMReader(String fileName) throws IOException {
this(new FileInputStream(fileName));
}
public byte[] getDerBytes() {
return derBytes;
}
public String getBeginMarker() {
return beginMarker;
}
/**
* Read the PEM file and save the DER encoded octet
* stream and begin marker.
*
* @throws IOException
*/
protected void readFile() throws IOException {
String line;
BufferedReader reader = new BufferedReader(
new InputStreamReader(stream));
try {
while ((line = reader.readLine()) != null)
{
if (line.indexOf(BEGIN_MARKER) != -1)
{
beginMarker = line.trim();
String endMarker = beginMarker.replace("BEGIN", "END");
derBytes = readBytes(reader, endMarker);
return;
}
}
throw new IOException("Invalid PEM file: no begin marker");
} finally {
reader.close();
}
}
/**
* Read the lines between BEGIN and END marker and convert
* the Base64 encoded content into binary byte array.
*
* @return DER encoded octet stream
* @throws IOException
*/
private byte[] readBytes(BufferedReader reader, String endMarker) throws IOException
{
String line = null;
StringBuffer buf = new StringBuffer();
while ((line = reader.readLine()) != null)
{
if (line.indexOf(endMarker) != -1) {
return OAuthSignatureMethod.decodeBase64(buf.toString());
}
buf.append(line.trim());
}
throw new IOException("Invalid PEM file: No end marker");
}
}