How can one programmatically obtain a KeyStore from a PEM file containing both a certificate and a private key? I am attempting to provide a client certificate to a server in an HTTPS connection. I have confirmed that the client certificate works if I use openssl and keytool to obtain a jks file, which I load dynamically. I can even get it to work by dynamically reading in a p12 (PKCS12) file.
I'm looking into using the PEMReader class from BouncyCastle, but I can't get past some errors. I'm running the Java client with the -Djavax.net.debug=all option and Apache web server with the debug LogLevel. I'm not sure what to look for though. The Apache error log indicates:
...
OpenSSL: Write: SSLv3 read client certificate B
OpenSSL: Exit: error in SSLv3 read client certificate B
Re-negotiation handshake failed: Not accepted by client!?
The Java client program indicates:
...
main, WRITE: TLSv1 Handshake, length = 48
main, waiting for close_notify or alert: state 3
main, Exception while waiting for close java.net.SocketException: Software caused connection abort: recv failed
main, handling exception: java.net.SocketException: Software caused connection abort: recv failed
%% Invalidated: [Session-3, TLS_RSA_WITH_AES_128_CBC_SHA]
main, SEND TLSv1 ALERT: fatal, description = unexpected_message
...
The client code :
public void testClientCertPEM() throws Exception {
String requestURL = "https://mydomain/authtest";
String pemPath = "C:/Users/myusername/Desktop/client.pem";
HttpsURLConnection con;
URL url = new URL(requestURL);
con = (HttpsURLConnection) url.openConnection();
con.setSSLSocketFactory(getSocketFactoryFromPEM(pemPath));
con.setRequestMethod("GET");
con.setDoInput(true);
con.setDoOutput(false);
con.connect();
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
while((line = reader.readLine()) != null) {
System.out.println(line);
}
reader.close();
con.disconnect();
}
public SSLSocketFactory getSocketFactoryFromPEM(String pemPath) throws Exception {
Security.addProvider(new BouncyCastleProvider());
SSLContext context = SSLContext.getInstance("TLS");
PEMReader reader = new PEMReader(new FileReader(pemPath));
X509Certificate cert = (X509Certificate) reader.readObject();
KeyStore keystore = KeyStore.getInstance("JKS");
keystore.load(null);
keystore.setCertificateEntry("alias", cert);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(keystore, null);
KeyManager[] km = kmf.getKeyManagers();
context.init(km, null, null);
return context.getSocketFactory();
}
I noticed the server is outputing SSLv3 in the log while the client is TLSv1. If I add the system property -Dhttps.protocols=SSLv3 then the client will use SSLv3 as well, but I get the same error message. I've also tried adding -Dsun.security.ssl.allowUnsafeRenegotiation=true with no change in outcome.
I've googled around and the usual answer for this question is to just use openssl and keytool first. In my case I need to read the PEM directly on the fly. I'm actually porting a C++ program that already does this, and frankly, I'm very surprised how difficult it is to do this in Java. The C++ code:
curlpp::Easy request;
...
request.setOpt(new Options::Url(myurl));
request.setOpt(new Options::SslVerifyPeer(false));
request.setOpt(new Options::SslCertType("PEM"));
request.setOpt(new Options::SslCert(cert));
request.perform();
I figured it out. The problem is that the X509Certificate by itself isn't sufficient. I needed to put the private key into the dynamically generated keystore as well. It doesn't seem that BouncyCastle PEMReader can handle a PEM file with both cert and private key all in one go, but it can handle each piece separately. I can read the PEM into memory myself and break it into two separate streams and then feed each one to a separate PEMReader. Since I know that the PEM files I'm dealing with will have the cert first and the private key second I can simplify the code at the cost of robustness. I also know that the END CERTIFICATE delimiter will always be surrounded with five hyphens. The implementation that works for me is:
protected static SSLSocketFactory getSocketFactoryPEM(String pemPath) throws Exception {
Security.addProvider(new BouncyCastleProvider());
SSLContext context = SSLContext.getInstance("TLS");
byte[] certAndKey = fileToBytes(new File(pemPath));
String delimiter = "-----END CERTIFICATE-----";
String[] tokens = new String(certAndKey).split(delimiter);
byte[] certBytes = tokens[0].concat(delimiter).getBytes();
byte[] keyBytes = tokens[1].getBytes();
PEMReader reader;
reader = new PEMReader(new InputStreamReader(new ByteArrayInputStream(certBytes)));
X509Certificate cert = (X509Certificate)reader.readObject();
reader = new PEMReader(new InputStreamReader(new ByteArrayInputStream(keyBytes)));
PrivateKey key = (PrivateKey)reader.readObject();
KeyStore keystore = KeyStore.getInstance("JKS");
keystore.load(null);
keystore.setCertificateEntry("cert-alias", cert);
keystore.setKeyEntry("key-alias", key, "changeit".toCharArray(), new Certificate[] {cert});
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(keystore, "changeit".toCharArray());
KeyManager[] km = kmf.getKeyManagers();
context.init(km, null, null);
return context.getSocketFactory();
}
Update: It seems this can be done without BouncyCastle:
byte[] certAndKey = fileToBytes(new File(pemPath));
byte[] certBytes = parseDERFromPEM(certAndKey, "-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----");
byte[] keyBytes = parseDERFromPEM(certAndKey, "-----BEGIN PRIVATE KEY-----", "-----END PRIVATE KEY-----");
X509Certificate cert = generateCertificateFromDER(certBytes);
RSAPrivateKey key = generatePrivateKeyFromDER(keyBytes);
...
protected static byte[] parseDERFromPEM(byte[] pem, String beginDelimiter, String endDelimiter) {
String data = new String(pem);
String[] tokens = data.split(beginDelimiter);
tokens = tokens[1].split(endDelimiter);
return DatatypeConverter.parseBase64Binary(tokens[0]);
}
protected static RSAPrivateKey generatePrivateKeyFromDER(byte[] keyBytes) throws InvalidKeySpecException, NoSuchAlgorithmException {
PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory factory = KeyFactory.getInstance("RSA");
return (RSAPrivateKey)factory.generatePrivate(spec);
}
protected static X509Certificate generateCertificateFromDER(byte[] certBytes) throws CertificateException {
CertificateFactory factory = CertificateFactory.getInstance("X.509");
return (X509Certificate)factory.generateCertificate(new ByteArrayInputStream(certBytes));
}