import org.bouncycastle.openssl.jcajce.JcePEMEncryptorBuilder; //导入依赖的package包/类
private byte[] serializePrivateKey(final KeyPair keyPair,
                                   final String passphrase) throws Exception {
    final ByteArrayOutputStream baos = new ByteArrayOutputStream();
    final JcaPEMWriter jcaPEMWriter = new JcaPEMWriter(new OutputStreamWriter(baos,
            StandardCharsets.US_ASCII));

    if (passphrase != null) {
        final PEMEncryptor pemEncryptor = new JcePEMEncryptorBuilder("AES-128-CBC").build(passphrase.toCharArray());
        final JcaMiscPEMGenerator pemGenerator = new JcaMiscPEMGenerator(keyPair.getPrivate(), pemEncryptor);
        jcaPEMWriter.writeObject(pemGenerator);
    } else {
        jcaPEMWriter.writeObject(keyPair.getPrivate());
    }

    jcaPEMWriter.flush();
    jcaPEMWriter.close();
    return baos.toByteArray();
}
 

import org.bouncycastle.openssl.jcajce.JcePEMEncryptorBuilder; //导入依赖的package包/类
/**
 * @deprecated use writeObject(obj, PEMEncryptor)
 */
public void writeObject(
    Object       obj,
    String       algorithm,
    char[]       password,
    SecureRandom random)
    throws IOException
{
    this.writeObject(obj, new JcePEMEncryptorBuilder(algorithm).setSecureRandom(random).setProvider(provider).build(password));
}
 

import org.bouncycastle.openssl.jcajce.JcePEMEncryptorBuilder; //导入依赖的package包/类
@Override
public String encodePrivateKeyAsPem(PrivateKey privateKey, String passwordForPrivateKey, String encryptionAlgorithm) {
    if (passwordForPrivateKey == null) {
        throw new IllegalArgumentException("You must specify a password when serializing a private key");
    }

    PEMEncryptor encryptor = new JcePEMEncryptorBuilder(encryptionAlgorithm)
            .build(passwordForPrivateKey.toCharArray());

    return encodeObjectAsPemString(privateKey, encryptor);
}
 

import org.bouncycastle.openssl.jcajce.JcePEMEncryptorBuilder; //导入依赖的package包/类
@AuthenticationRequired
@RequestMapping(value = "certificates/exportPem/{id}", method = RequestMethod.POST, produces = { "application/json" })
@ResponseStatus(value = HttpStatus.OK)
@ResponseBody
public RequestStatus exportPem(HttpServletRequest request,
		HttpServletResponse response, @PathVariable Long id,
		@RequestParam(value = "passphrase") String passphrase)
		throws AccessDeniedException, UnauthorizedException,
		SessionTimeoutException {

	setupAuthenticatedContext(sessionUtils.getSession(request),
			sessionUtils.getLocale(request));

	try {
		CertificateStatus status = new CertificateStatus();
		status.setSuccess(false);
		try {

			CertificateResource resource = resourceService
					.getResourceById(id);

			ByteArrayOutputStream out = new ByteArrayOutputStream();
			ZipOutputStream zip = new ZipOutputStream(
					new BufferedOutputStream(out));

			zip.putNextEntry(new ZipEntry("certificate.pem"));
			zip.write(resource.getCertificate().getBytes("UTF-8"));
			zip.closeEntry();

			if (StringUtils.isNotEmpty(resource.getBundle())) {
				zip.putNextEntry(new ZipEntry("ca-bundle.pem"));
				zip.write(resource.getBundle().getBytes("UTF-8"));
				zip.closeEntry();
			}
			zip.putNextEntry(new ZipEntry("key.pem"));
			if (passphrase == null || passphrase.trim().equals("")) {
				zip.write(resource.getPrivateKey().getBytes("UTF-8"));
			} else {
				KeyPair keypair = X509CertificateUtils.loadKeyPairFromPEM(
						new ByteArrayInputStream(resource.getPrivateKey()
								.getBytes("UTF-8")), passphrase
								.toCharArray());
				ByteArrayOutputStream bout = new ByteArrayOutputStream();
				JcaPEMWriter pem = new JcaPEMWriter(
						new OutputStreamWriter(bout));
				pem.writeObject(
						keypair,
						new JcePEMEncryptorBuilder("AES-128-CBC")
								.setProvider("BC").build(
										passphrase.toCharArray()));
				pem.flush();
				zip.write(bout.toByteArray());
				pem.close();
				bout.close();
			}
			zip.closeEntry();
			zip.close();
			request.getSession().setAttribute("pem", out.toByteArray());
			return new RequestStatus(true);
		} catch (Exception e) {
			return new RequestStatus(false, e.getMessage());
		}
	} finally {
		clearAuthenticatedContext();
	}
}