public class CertificateFactory extends Object
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.509CertPath encodings:
PKCS7PkiPathCertificate,
X509Certificate| Constructor and Description |
|---|
CertificateFactory() |
| Modifier and Type | Method and Description |
|---|---|
Certificate |
generateCertificate(InputStream inStream)
Generates a certificate object and initializes it with
the data read from the input stream
inStream. |
static CertificateFactory |
getInstance(String type)
Returns a certificate factory object that implements the
specified certificate type.
|
String |
getType()
Returns the name of the certificate type associated with this
certificate factory.
|
public final Certificate generateCertificate(InputStream inStream) throws CertificateException
inStream.
In order to take advantage of the specialized certificate format
supported by this certificate factory,
the returned certificate object can be typecast to the corresponding
certificate class. For example, if this certificate
factory implements X.509 certificates, the returned certificate object
can be typecast to the X509Certificate class.
In the case of a certificate factory for X.509 certificates, the
certificate provided in inStream must be DER-encoded and
may be supplied in binary or printable (Base64) encoding. If the
certificate is provided in Base64 encoding, it must be bounded at
the beginning by -----BEGIN CERTIFICATE-----, and must be bounded at
the end by -----END CERTIFICATE-----.
Note that if the given input stream does not support
mark and
reset, this method will
consume the entire input stream. Otherwise, each call to this
method consumes one certificate and the read position of the
input stream is positioned to the next available byte after
the inherent end-of-certificate marker. If the data in the input stream
does not contain an inherent end-of-certificate marker (other
than EOF) and there is trailing data after the certificate is parsed, a
CertificateException is thrown.
inStream - an input stream with the certificate data.CertificateException - on parsing errors.public static final CertificateFactory getInstance(String type) throws CertificateException
This method traverses the list of registered security Providers, starting with the most preferred Provider. A new CertificateFactory object encapsulating the CertificateFactorySpi implementation from the first Provider that supports the specified type is returned.
type - the name of the requested certificate type.
See the CertificateFactory section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard certificate types.CertificateException - if no Provider supports a
CertificateFactorySpi implementation for the
specified type.public final String getType()