programmatically import .cer certificate into keystore

Question

How can I import a .p12 certificate from the classpath into the java keystore? First I used the InstallCert https://code.google.com/p/java-use-examples/source/browse/trunk/src/com/aw/ad/util/InstallCert.java and did some changes so the server certificate will be imported into the keystore in the java install directory. This works fine but now I want to load a certificate from my classpath.

EDIT: I just use a .cer certificate, see next answer

As you solved your own question you should put it as an answer. It helped me because this is an issue that I will have to deal in a near future. So it can help others. — Jorge Campos, Jul 23 '14 at 14:16

score 27 · Accepted Answer · edited Aug 05 '20 at 03:45

The answer:

InputStream certIn = ClassLoader.class.getResourceAsStream("/package/myCert.cer");

final char sep = File.separatorChar;
File dir = new File(System.getProperty("java.home") + sep + "lib" + sep + "security");
File file = new File(dir, "cacerts");
InputStream localCertIn = new FileInputStream(file);

KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(localCertIn, passphrase);
if (keystore.containsAlias("myAlias")) {
    certIn.close();
    localCertIn.close();
    return;
}
localCertIn.close();

BufferedInputStream bis = new BufferedInputStream(certIn);
CertificateFactory cf = CertificateFactory.getInstance("X.509");
while (bis.available() > 0) {
    Certificate cert = cf.generateCertificate(bis);
    keystore.setCertificateEntry("myAlias", cert);
}

certIn.close();

OutputStream out = new FileOutputStream(file);
keystore.store(out, passphrase);
out.close();

For Java Web Start don't use the ClassLoader, use the Class itself:

InputStream certIn = Certificates.class.getResourceAsStream("/package/myCert.cer");

any clue how to solve the problem about access denied? (though i am administrator) java.io.FileNotFoundException: C:\Program Files (x86)\Java\jre1.8.0_45\lib\security\cacerts (Access is denied) — lumo, Jun 07 '15 at 19:12
Maybe the file is already in use by another process? Maybe you have some permission issues of the files and folders and Java itself dont have permission? Otherwise no clue ... also this solution worked in Java7 so there maybe this no longer works in Java8? — Pali, Jun 08 '15 at 06:54

score -1 · Answer 2 · answered Nov 17 '19 at 03:46

-1

I run into "java.io.FileNotFoundException: C:\Program Files (x86)\Java\jre1.8.0_45\lib\security\cacerts (Access is denied)" issue as well. I have to go to the folder \securiyy and grant permission manually to access h

answered Nov 17 '19 at 03:46

Feng Zhang

920
8
16

programmatically import .cer certificate into keystore

2 Answers2

Linked