Module java.base
Package java.security.cert

Class CertificateFactory

java.lang.Object
java.security.cert.CertificateFactory
public class CertificateFactory extends Object
This class defines the functionality of a certificate factory, which is used to generate certificate, certification path (CertPath) and certificate revocation list (CRL) objects from their encodings.

For encodings consisting of multiple certificates, use generateCertificates when you want to parse a collection of possibly unrelated certificates. Otherwise, use generateCertPath when you want to generate a CertPath (a certificate chain) and subsequently validate it with a CertPathValidator.

A certificate factory for X.509 must return certificates that are an instance of java.security.cert.X509Certificate, and CRLs that are an instance of java.security.cert.X509CRL.

The following example reads a file with Base64 encoded certificates, which are each bounded at the beginning by -----BEGIN CERTIFICATE-----, and bounded at the end by -----END CERTIFICATE-----. We convert the FileInputStream (which does not support mark and reset) to a BufferedInputStream (which supports those methods), so that each call to generateCertificate consumes only one certificate, and the read position of the input stream is positioned to the next certificate in the file: 


 FileInputStream fis = new FileInputStream(filename);
 BufferedInputStream bis = new BufferedInputStream(fis);

 CertificateFactory cf = CertificateFactory.getInstance("X.509");

 while (bis.available() > 0) {
    Certificate cert = cf.generateCertificate(bis);
    System.out.println(cert.toString());
 }

The following example parses a PKCS#7-formatted certificate reply stored in a file and extracts all the certificates from it: 

 FileInputStream fis = new FileInputStream(filename);
 CertificateFactory cf = CertificateFactory.getInstance("X.509");
 Collection c = cf.generateCertificates(fis);
 Iterator i = c.iterator();
 while (i.hasNext()) {
    Certificate cert = (Certificate)i.next();
    System.out.println(cert);
 }

Every implementation of the Java platform is required to support the following standard CertificateFactory type:

  • X.509
and the following standard CertPath encodings:
  • PKCS7
  • PkiPath
The type and encodings are described in the CertificateFactory section and the CertPath Encodings section of the Java Security Standard Algorithm Names Specification. Consult the release documentation for your implementation to see if any other types or encodings are supported.
Since:
1.2
See Also: