/** * $RCSfile$ * $Revision: $ * $Date: $ * * Copyright (C) 2006 Jive Software. All rights reserved. * * This software is published under the terms of the GNU Public License (GPL), * a copy of which is included in this distribution. */ package org.jivesoftware.util; import org.bouncycastle.asn1.*; import org.bouncycastle.asn1.x509.GeneralName; import org.bouncycastle.asn1.x509.GeneralNames; import org.bouncycastle.asn1.x509.X509Extensions; import org.bouncycastle.asn1.x509.X509Name; import org.bouncycastle.jce.PKCS10CertificationRequest; import org.bouncycastle.jce.provider.BouncyCastleProvider; import org.bouncycastle.openssl.PEMReader; import org.bouncycastle.x509.X509V3CertificateGenerator; import java.io.*; import java.math.BigInteger; import java.security.*; import java.security.cert.Certificate; import java.security.cert.CertificateFactory; import java.security.cert.CertificateParsingException; import java.security.cert.X509Certificate; import java.util.*; import java.util.LinkedList; import java.util.concurrent.CopyOnWriteArrayList; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Utility class that provides similar functionality to the keytool tool. Generated certificates * conform to the XMPP spec where domains are kept in the subject alternative names extension. * * @author Gaston Dombiak */ public class CertificateManager { private static Pattern cnPattern = Pattern.compile("(?i)(cn=)([^,]*)"); private static Provider provider = new BouncyCastleProvider(); /** * The maximum length of lines in certification requests */ private static final int CERT_REQ_LINE_LENGTH = 76; private static List<CertificateEventListener> listeners = new CopyOnWriteArrayList<CertificateEventListener>(); static { // Add the BC provider to the list of security providers Security.addProvider(provider); } /** * Creates a new X509 certificate using the DSA algorithm. The new certificate together with its private * key are stored in the specified key store. However, the key store is not saved to the disk. This means * that it is up to the "caller" to save the key store to disk after new certificates have been added * to the store. * * @param ksKeys key store where the new certificate and private key are going to be stored. * @param keyPassword password of the keystore. * @param alias name to use when storing the certificate in the key store. * @param issuerDN Issuer string e.g "O=Grid,OU=OGSA,CN=ACME" * @param subjectDN Subject string e.g "O=Grid,OU=OGSA,CN=John Doe" * @param domain domain of the server to store in the subject alternative name extension. * @return the new X509 V3 Certificate. * @throws GeneralSecurityException * @throws IOException */ public static X509Certificate createDSACert(KeyStore ksKeys, String keyPassword, String alias, String issuerDN, String subjectDN, String domain) throws GeneralSecurityException, IOException { // Generate public and private keys KeyPair keyPair = generateKeyPair("DSA", 1024); // Create X509 certificate with keys and specified domain X509Certificate cert = createX509V3Certificate(keyPair, 60, issuerDN, subjectDN, domain, "SHA1withDSA"); // Store new certificate and private key in the keystore ksKeys.setKeyEntry(alias, keyPair.getPrivate(), keyPassword.toCharArray(), new X509Certificate[]{cert}); // Notify listeners that a new certificate has been created for (CertificateEventListener listener : listeners) { try { listener.certificateCreated(ksKeys, alias, cert); } catch (Exception e) { Log.error(e); } } // Return new certificate return cert; } /** * Creates a new X509 certificate using the RSA algorithm. The new certificate together with its private * key are stored in the specified key store. However, the key store is not saved to the disk. This means * that it is up to the "caller" to save the key store to disk after new certificates have been added * to the store. * * @param ksKeys key store where the new certificate and private key are going to be stored. * @param keyPassword password of the keystore. * @param alias name to use when storing the certificate in the key store. * @param issuerDN Issuer string e.g "O=Grid,OU=OGSA,CN=ACME" * @param subjectDN Subject string e.g "O=Grid,OU=OGSA,CN=John Doe" * @param domain domain of the server to store in the subject alternative name extension. * @return the new X509 V3 Certificate. * @throws GeneralSecurityException * @throws IOException */ public static X509Certificate createRSACert(KeyStore ksKeys, String keyPassword, String alias, String issuerDN, String subjectDN, String domain) throws GeneralSecurityException, IOException { // Generate public and private keys KeyPair keyPair = generateKeyPair("RSA", 1024); // Create X509 certificate with keys and specified domain X509Certificate cert = createX509V3Certificate(keyPair, 60, issuerDN, subjectDN, domain, "MD5withRSA"); // Store new certificate and private key in the keystore ksKeys.setKeyEntry(alias, keyPair.getPrivate(), keyPassword.toCharArray(), new X509Certificate[]{cert}); // Notify listeners that a new certificate has been created for (CertificateEventListener listener : listeners) { try { listener.certificateCreated(ksKeys, alias, cert); } catch (Exception e) { Log.error(e); } } // Return new certificate return cert; } /** * Deletes the specified certificate from the * * @param ksKeys key store where the certificate is stored. * @param alias alias of the certificate to delete. * @throws GeneralSecurityException * @throws IOException */ public static void deleteCertificate(KeyStore ksKeys, String alias) throws GeneralSecurityException, IOException { ksKeys.deleteEntry(alias); // Notify listeners that a new certificate has been created for (CertificateEventListener listener : listeners) { try { listener.certificateDeleted(ksKeys, alias); } catch (Exception e) { Log.error(e); } } } /** * Returns the identities of the remote server as defined in the specified certificate. The * identities are defined in the subjectDN of the certificate and it can also be defined in * the subjectAltName extensions of type "xmpp". When the extension is being used then the * identities defined in the extension are going to be returned. Otherwise, the value stored in * the subjectDN is returned. * * @param x509Certificate the certificate the holds the identities of the remote server. * @return the identities of the remote server as defined in the specified certificate. */ public static List<String> getPeerIdentities(X509Certificate x509Certificate) { // Look the identity in the subjectAltName extension if available List<String> names = getSubjectAlternativeNames(x509Certificate); if (names.isEmpty()) { String name = x509Certificate.getSubjectDN().getName(); Matcher matcher = cnPattern.matcher(name); if (matcher.find()) { name = matcher.group(2); } // Create an array with the unique identity names = new ArrayList<String>(); names.add(name); } return names; } /** * Returns the JID representation of an XMPP entity contained as a SubjectAltName extension * in the certificate. If none was found then return <tt>null</tt>. * * @param certificate the certificate presented by the remote entity. * @return the JID representation of an XMPP entity contained as a SubjectAltName extension * in the certificate. If none was found then return <tt>null</tt>. */ private static List<String> getSubjectAlternativeNames(X509Certificate certificate) { List<String> identities = new ArrayList<String>(); try { Collection<List<?>> altNames = certificate.getSubjectAlternativeNames(); // Check that the certificate includes the SubjectAltName extension if (altNames == null) { return Collections.emptyList(); } // Use the type OtherName to search for the certified server name for (List item : altNames) { Integer type = (Integer) item.get(0); if (type == 0) { // Type OtherName found so return the associated value try { // Value is encoded using ASN.1 so decode it to get the server's identity ASN1InputStream decoder = new ASN1InputStream((byte[]) item.toArray()[1]); DEREncodable encoded = decoder.readObject(); encoded = ((DERSequence) encoded).getObjectAt(1); encoded = ((DERTaggedObject) encoded).getObject(); encoded = ((DERTaggedObject) encoded).getObject(); String identity = ((DERUTF8String) encoded).getString(); if (!"".equals(identity)) { // Add the decoded server name to the list of identities identities.add(identity); } } catch (UnsupportedEncodingException e) { // Ignore } catch (IOException e) { // Ignore } catch (Exception e) { Log.error("Error decoding subjectAltName", e); } } // Other types are not good for XMPP so ignore them else if (Log.isDebugEnabled()) { Log.debug("SubjectAltName of invalid type found: " + certificate); } } } catch (CertificateParsingException e) { Log.error("Error parsing SubjectAltName in certificate: " + certificate, e); } return identities; } /** * Returns true if an RSA certificate was found in the specified keystore for the specified domain. * * @param ksKeys the keystore that contains the certificates. * @param domain domain of the server signed by the certificate. * @return true if an RSA certificate was found in the specified keystore for the specified domain. * @throws KeyStoreException */ public static boolean isRSACertificate(KeyStore ksKeys, String domain) throws KeyStoreException { return isCertificate(ksKeys, domain, "RSA"); } /** * Returns true if an DSA certificate was found in the specified keystore for the specified domain. * * @param ksKeys the keystore that contains the certificates. * @param domain domain of the server signed by the certificate. * @return true if an DSA certificate was found in the specified keystore for the specified domain. * @throws KeyStoreException */ public static boolean isDSACertificate(KeyStore ksKeys, String domain) throws KeyStoreException { return isCertificate(ksKeys, domain, "DSA"); } /** * Returns true if the specified certificate is using the DSA algorithm. The DSA algorithm is not * good for encryption but only for authentication. On the other hand, the RSA algorithm is good * for encryption and authentication. * * @param certificate the certificate to analyze. * @return true if the specified certificate is using the DSA algorithm. * @throws KeyStoreException */ public static boolean isDSACertificate(X509Certificate certificate) throws KeyStoreException { return certificate.getPublicKey().getAlgorithm().equals("DSA"); } /** * Returns true if a certificate with the specifed configuration was found in the key store. * * @param ksKeys the keystore to use for searching the certificate. * @param domain the domain present in the subjectAltName or "*" if anything is accepted. * @param algorithm the DSA or RSA algorithm used by the certificate. * @return true if a certificate with the specifed configuration was found in the key store. * @throws KeyStoreException */ private static boolean isCertificate(KeyStore ksKeys, String domain, String algorithm) throws KeyStoreException { for (Enumeration<String> aliases = ksKeys.aliases(); aliases.hasMoreElements();) { X509Certificate certificate = (X509Certificate) ksKeys.getCertificate(aliases.nextElement()); if ("*".equals(domain)) { // Any domain certified by the certificate is accepted if (certificate.getPublicKey().getAlgorithm().equals(algorithm)) { return true; } } else { // Only accept certified domains that match the specified domain for (String identity : getPeerIdentities(certificate)) { if (identity.endsWith(domain) && certificate.getPublicKey().getAlgorithm().equals(algorithm)) { return true; } } } } return false; } /** * Creates and returns the content of a new singing request for the specified certificate. Signing * requests are required by Certificate Authorities as part of their signing process. The signing request * contains information about the certificate issuer, subject DN, subject alternative names and public key. * Private keys are not included. After the Certificate Authority verified and signed the certificate a new * certificate is going to be returned. Use {@link #installReply(java.security.KeyStore, java.security.KeyStore, String, String, java.io.InputStream, boolean, boolean)} * to import the CA reply. * * @param cert the certificate to create a signing request. * @param privKey the private key of the certificate. * @return the content of a new singing request for the specified certificate. * @throws Exception */ public static String createSigningRequest(X509Certificate cert, PrivateKey privKey) throws Exception { StringBuilder sb = new StringBuilder(); String subject = cert.getSubjectDN().getName(); X509Name xname = new X509Name(subject); PublicKey pubKey = cert.getPublicKey(); String signatureAlgorithm = "DSA".equals(pubKey.getAlgorithm()) ? "SHA1withDSA" : "MD5withRSA"; PKCS10CertificationRequest csr = new PKCS10CertificationRequest(signatureAlgorithm, xname, pubKey, null, privKey); ByteArrayOutputStream baos = new ByteArrayOutputStream(); DEROutputStream deros = new DEROutputStream(baos); deros.writeObject(csr.getDERObject()); String sTmp = new String(org.bouncycastle.util.encoders.Base64.encode(baos.toByteArray())); // Header sb.append("-----BEGIN NEW CERTIFICATE REQUEST-----\n"); // Add signing request content (base 64 encoded) for (int iCnt = 0; iCnt < sTmp.length(); iCnt += CERT_REQ_LINE_LENGTH) { int iLineLength; if ((iCnt + CERT_REQ_LINE_LENGTH) > sTmp.length()) { iLineLength = sTmp.length() - iCnt; } else { iLineLength = CERT_REQ_LINE_LENGTH; } sb.append(sTmp.substring(iCnt, iCnt + iLineLength)).append("\n"); } // Footer sb.append("-----END NEW CERTIFICATE REQUEST-----\n"); return sb.toString(); } /** * Installs the Certificate Authority reply returned as part of the signing request. The certificate * being signed will get its certificate chain updated with the imported certificate(s). An exception * will be thrown if the replied certificate does not match a local certificate or if the signing * authority is not known by the server (i.e. keystore and truststore files). When <tt>trustCACerts</tt> * is set to <tt>true</tt> then certificates present in the truststore file will be used to verify the * identity of the entity signing the certificate. In case the reply is composed of more than one * certificate then you can also specify if you want to verify that the root certificate in the chain * can be trusted. * * @param keyStore key store where the certificate is stored. * @param trustStore key store where ca certificates are stored. * @param keyPassword password of the keystore. * @param alias the alias of the existing certificate being signed. * @param inputStream the stream containing the CA reply. * @param trustCACerts true if certificates present in the truststore file will be used to verify the * identity of the entity signing the certificate. * @param validateRoot true if you want to verify that the root certificate in the chain can be trusted * based on the truststore. * @return true if the CA reply was successfully processed. * @throws Exception */ public static boolean installReply(KeyStore keyStore, KeyStore trustStore, String keyPassword, String alias, InputStream inputStream, boolean trustCACerts, boolean validateRoot) throws Exception { // Check that there is a certificate for the specified alias X509Certificate certificate = (X509Certificate) keyStore.getCertificate(alias); if (certificate == null) { Log.warn("Certificate not found for alias: " + alias); return false; } // Retrieve the private key of the stored certificate PrivateKey privKey = (PrivateKey) keyStore.getKey(alias, keyPassword.toCharArray()); // Load certificates found in the PEM input stream List<X509Certificate> certs = new ArrayList<X509Certificate>(); for (Certificate cert : CertificateFactory.getInstance("X509").generateCertificates(inputStream)) { certs.add((X509Certificate) cert); } if (certs.isEmpty()) { throw new Exception("Reply has no certificates"); } List<X509Certificate> newCerts; if (certs.size() == 1) { // Reply has only one certificate newCerts = establishCertChain(keyStore, trustStore, null, certs.get(0), trustCACerts); } else { // Reply has a chain of certificates newCerts = validateReply(keyStore, trustStore, alias, null, certs, trustCACerts, validateRoot); } if (newCerts != null) { keyStore.setKeyEntry(alias, privKey, keyPassword.toCharArray(), newCerts.toArray(new X509Certificate[newCerts.size()])); // Notify listeners that a new certificate has been created for (CertificateEventListener listener : listeners) { try { listener.certificateSigned(keyStore, alias, newCerts); } catch (Exception e) { Log.error(e); } } return true; } else { return false; } } /** * Imports a new signed certificate and its private key into the keystore. The certificate input * stream may contain the signed certificate as well as its CA chain. * * @param keyStore key store where the certificate will be stored. * @param trustStore key store where ca certificates are stored. * @param keyPassword password of the keystore. * @param alias the alias of the the new signed certificate. * @param pkInputStream the stream containing the private key. * @param inputStream the stream containing the signed certificate. * @param trustCACerts true if certificates present in the truststore file will be used to verify the * identity of the entity signing the certificate. * @param validateRoot true if you want to verify that the root certificate in the chain can be trusted * based on the truststore. * @return true if the certificate was successfully imported. * @throws Exception if no certificates were found in the inputStream. */ public static boolean installCert(KeyStore keyStore, KeyStore trustStore, String keyPassword, String alias, InputStream pkInputStream, InputStream inputStream, boolean trustCACerts, boolean validateRoot) throws Exception { // Check that there is a certificate for the specified alias X509Certificate certificate = (X509Certificate) keyStore.getCertificate(alias); if (certificate != null) { Log.warn("Certificate already exists for alias: " + alias); return false; } // Retrieve the private key of the stored certificate PEMReader pemReader = new PEMReader(new InputStreamReader(pkInputStream)); KeyPair kp = (KeyPair) pemReader.readObject(); PrivateKey privKey = kp.getPrivate(); // Load certificates found in the PEM input stream List<X509Certificate> certs = new ArrayList<X509Certificate>(); for (Certificate cert : CertificateFactory.getInstance("X509").generateCertificates(inputStream)) { certs.add((X509Certificate) cert); } if (certs.isEmpty()) { throw new Exception("No certificates were found"); } List<X509Certificate> newCerts; if (certs.size() == 1) { // Reply has only one certificate newCerts = establishCertChain(keyStore, trustStore, certificate, certs.get(0), trustCACerts); } else { // Reply has a chain of certificates newCerts = validateReply(keyStore, trustStore, alias, certificate, certs, trustCACerts, validateRoot); } if (newCerts != null) { keyStore.setKeyEntry(alias, privKey, keyPassword.toCharArray(), newCerts.toArray(new X509Certificate[newCerts.size()])); // Notify listeners that a new certificate has been created (and signed) for (CertificateEventListener listener : listeners) { try { listener.certificateCreated(keyStore, alias, certs.get(0)); if (newCerts.size() > 1) { listener.certificateSigned(keyStore, alias, newCerts); } } catch (Exception e) { Log.error(e); } } return true; } else { return false; } } /** * Registers a listener to receive events. * * @param listener the listener. */ public static void addListener(CertificateEventListener listener) { if (listener == null) { throw new NullPointerException(); } listeners.add(listener); } /** * Unregisters a listener to receive events. * * @param listener the listener. */ public static void removeListener(CertificateEventListener listener) { listeners.remove(listener); } private static List<X509Certificate> establishCertChain(KeyStore keyStore, KeyStore trustStore, X509Certificate certificate, X509Certificate certReply, boolean trustCACerts) throws Exception { if (certificate != null) { PublicKey publickey = certificate.getPublicKey(); PublicKey publickey1 = certReply.getPublicKey(); if (!publickey.equals(publickey1)) { throw new Exception("Public keys in reply and keystore don't match"); } if (certReply.equals(certificate)) { throw new Exception("Certificate reply and certificate in keystore are identical"); } } Map<Principal, List<X509Certificate>> knownCerts = new Hashtable<Principal, List<X509Certificate>>(); if (keyStore.size() > 0) { knownCerts.putAll(getCertsByIssuer(keyStore)); } if (trustCACerts && trustStore.size() > 0) { knownCerts.putAll(getCertsByIssuer(trustStore)); } LinkedList<X509Certificate> answer = new LinkedList<X509Certificate>(); if (buildChain(certReply, answer, knownCerts)) { return answer; } else { throw new Exception("Failed to establish chain from reply"); } } /** * Builds the certificate chain of the specified certificate based on the known list of certificates * that were issued by their respective Principals. Returns true if the entire chain of all certificates * was successfully built. * * @param certificate certificate to build its chain. * @param answer the certificate chain for the corresponding certificate. * @param knownCerts list of known certificates grouped by their issues (i.e. Principals). * @return true if the entire chain of all certificates was successfully built. */ private static boolean buildChain(X509Certificate certificate, LinkedList<X509Certificate> answer, Map<Principal, List<X509Certificate>> knownCerts) { Principal subject = certificate.getSubjectDN(); Principal issuer = certificate.getIssuerDN(); // Check if the certificate is a root certificate (i.e. was issued by the same Principal that // is present in the subject) if (subject.equals(issuer)) { answer.addFirst(certificate); return true; } // Get the list of known certificates of the certificate's issuer List<X509Certificate> issuerCerts = knownCerts.get(issuer); if (issuerCerts == null || issuerCerts.isEmpty()) { // No certificates were found so building of chain failed return false; } for (X509Certificate issuerCert : issuerCerts) { PublicKey publickey = issuerCert.getPublicKey(); try { // Verify the certificate with the specified public key certificate.verify(publickey); // Certificate was verified successfully so build chain of issuer's certificate if (!buildChain(issuerCert, answer, knownCerts)) { return false; } } catch (Exception exception) { // Failed to verify certificate return false; } } answer.addFirst(certificate); return true; } /** * Returns a Map where the key holds the certificate issuers and values the certificates of each issuer. * * @param ks the keystore to get its certs per issuer. * @return a map with the certificates per issuer. * @throws Exception */ private static Map<Principal, List<X509Certificate>> getCertsByIssuer(KeyStore ks) throws Exception { Map<Principal, List<X509Certificate>> answer = new HashMap<Principal, List<X509Certificate>>(); Enumeration<String> aliases = ks.aliases(); while (aliases.hasMoreElements()) { String alias = aliases.nextElement(); X509Certificate cert = (X509Certificate) ks.getCertificate(alias); if (cert != null) { Principal subjectDN = cert.getSubjectDN(); List<X509Certificate> vec = answer.get(subjectDN); if (vec == null) { vec = new ArrayList<X509Certificate>(); vec.add(cert); } else { if (!vec.contains(cert)) { vec.add(cert); } } answer.put(subjectDN, vec); } } return answer; } /** * Validates chain in certification reply, and returns the ordered * elements of the chain (with user certificate first, and root * certificate last in the array). * * @param alias the alias name * @param userCert the user certificate of the alias * @param replyCerts the chain provided in the reply */ private static List<X509Certificate> validateReply(KeyStore keyStore, KeyStore trustStore, String alias, X509Certificate userCert, List<X509Certificate> replyCerts, boolean trustCACerts, boolean verifyRoot) throws Exception { // order the certs in the reply (bottom-up). int i; X509Certificate tmpCert; if (userCert != null) { PublicKey userPubKey = userCert.getPublicKey(); for (i = 0; i < replyCerts.size(); i++) { if (userPubKey.equals(replyCerts.get(i).getPublicKey())) { break; } } if (i == replyCerts.size()) { throw new Exception( "Certificate reply does not contain public key for <alias>: " + alias); } tmpCert = replyCerts.get(0); replyCerts.set(0, replyCerts.get(i)); replyCerts.set(i, tmpCert); } Principal issuer = replyCerts.get(0).getIssuerDN(); for (i = 1; i < replyCerts.size() - 1; i++) { // find a cert in the reply whose "subject" is the same as the // given "issuer" int j; for (j = i; j < replyCerts.size(); j++) { Principal subject = replyCerts.get(j).getSubjectDN(); if (subject.equals(issuer)) { tmpCert = replyCerts.get(i); replyCerts.set(i, replyCerts.get(j)); replyCerts.set(j, tmpCert); issuer = replyCerts.get(i).getIssuerDN(); break; } } if (j == replyCerts.size()) { throw new Exception("Incomplete certificate chain in reply"); } } // now verify each cert in the ordered chain for (i = 0; i < replyCerts.size() - 1; i++) { PublicKey pubKey = replyCerts.get(i + 1).getPublicKey(); try { replyCerts.get(i).verify(pubKey); } catch (Exception e) { throw new Exception( "Certificate chain in reply does not verify: " + e.getMessage()); } } if (!verifyRoot) { return replyCerts; } // do we trust the (root) cert at the top? X509Certificate topCert = replyCerts.get(replyCerts.size() - 1); boolean foundInKeyStore = keyStore.getCertificateAlias(topCert) != null; boolean foundInCAStore = trustCACerts && (trustStore.getCertificateAlias(topCert) != null); if (!foundInKeyStore && !foundInCAStore) { boolean verified = false; X509Certificate rootCert = null; if (trustCACerts) { for (Enumeration<String> aliases = trustStore.aliases(); aliases.hasMoreElements();) { String name = aliases.nextElement(); rootCert = (X509Certificate) trustStore.getCertificate(name); if (rootCert != null) { try { topCert.verify(rootCert.getPublicKey()); verified = true; break; } catch (Exception e) { // Ignore } } } } if (!verified) { return null; } else { // Check if the cert is a self-signed cert if (!topCert.getSubjectDN().equals(topCert.getIssuerDN())) { // append the (self-signed) root CA cert to the chain replyCerts.add(rootCert); } } } return replyCerts; } /** * Creates an X509 version3 certificate. * * @param kp KeyPair that keeps the public and private keys for the new certificate. * @param months time to live * @param issuerDN Issuer string e.g "O=Grid,OU=OGSA,CN=ACME" * @param subjectDN Subject string e.g "O=Grid,OU=OGSA,CN=John Doe" * @param domain Domain of the server. * @param signAlgoritm Signature algorithm. This can be either a name or an OID. * @return X509 V3 Certificate * @throws GeneralSecurityException * @throws IOException */ private static synchronized X509Certificate createX509V3Certificate(KeyPair kp, int months, String issuerDN, String subjectDN, String domain, String signAlgoritm) throws GeneralSecurityException, IOException { PublicKey pubKey = kp.getPublic(); PrivateKey privKey = kp.getPrivate(); byte[] serno = new byte[8]; SecureRandom random = SecureRandom.getInstance("SHA1PRNG"); random.setSeed((new Date().getTime())); random.nextBytes(serno); BigInteger serial = (new java.math.BigInteger(serno)).abs(); X509V3CertificateGenerator certGenerator = new X509V3CertificateGenerator(); certGenerator.reset(); certGenerator.setSerialNumber(serial); certGenerator.setIssuerDN(new X509Name(issuerDN)); certGenerator.setNotBefore(new Date(System.currentTimeMillis())); certGenerator.setNotAfter( new Date(System.currentTimeMillis() + months * (1000L * 60 * 60 * 24 * 30))); certGenerator.setSubjectDN(new X509Name(subjectDN)); certGenerator.setPublicKey(pubKey); certGenerator.setSignatureAlgorithm(signAlgoritm); // Generate the subject alternative name boolean critical = subjectDN == null || "".equals(subjectDN.trim()); DERSequence othernameSequence = new DERSequence(new ASN1Encodable[]{ new DERObjectIdentifier("1.3.6.1.5.5.7.8.5"), new DERTaggedObject(true, 0, new DERUTF8String(domain))}); GeneralName othernameGN = new GeneralName(GeneralName.otherName, othernameSequence); GeneralNames subjectAltNames = new GeneralNames(new DERSequence(new ASN1Encodable[]{othernameGN})); // Add subject alternative name extension certGenerator.addExtension(X509Extensions.SubjectAlternativeName, critical, subjectAltNames); X509Certificate cert = certGenerator.generateX509Certificate(privKey, "BC", new SecureRandom()); cert.checkValidity(new Date()); cert.verify(pubKey); return cert; } /** * Returns a new public & private key with the specified algorithm (e.g. DSA, RSA, etc.). * * @param algorithm DSA, RSA, etc. * @param keysize the keysize. This is an algorithm-specific metric, such as modulus * length, specified in number of bits. * @return a new public & private key with the specified algorithm (e.g. DSA, RSA, etc.). * @throws GeneralSecurityException */ private static KeyPair generateKeyPair(String algorithm, int keysize) throws GeneralSecurityException { KeyPairGenerator generator; if (provider == null) { generator = KeyPairGenerator.getInstance(algorithm); } else { generator = KeyPairGenerator.getInstance(algorithm, provider); } generator.initialize(keysize, new SecureRandom()); return generator.generateKeyPair(); } }