public abstract class X509Certificate extends Certificate implements X509Extension
Abstract class for X.509 certificates. This provides a standard way to access all the attributes of an X.509 certificate.
In June of 1996, the basic X.509 v3 format was completed by ISO/IEC and ANSI X9, which is described below in ASN.1:
Certificate ::= SEQUENCE {
tbsCertificate TBSCertificate,
signatureAlgorithm AlgorithmIdentifier,
signature BIT STRING }
These certificates are widely used to support authentication and other functionality in Internet security systems. Common applications include Privacy Enhanced Mail (PEM), Transport Layer Security (SSL), code signing for trusted software distribution, and Secure Electronic Transactions (SET).
These certificates are managed and vouched for by Certificate Authorities (CAs). CAs are services which create certificates by placing data in the X.509 standard format and then digitally signing that data. CAs act as trusted third parties, making introductions between principals who have no direct knowledge of each other. CA certificates are either signed by themselves, or by some other CA such as a "root" CA.
More information can be found in RFC 3280: Internet X.509 Public Key Infrastructure Certificate and CRL Profile.
The ASN.1 definition of tbsCertificate is:
TBSCertificate ::= SEQUENCE {
version [0] EXPLICIT Version DEFAULT v1,
serialNumber CertificateSerialNumber,
signature AlgorithmIdentifier,
issuer Name,
validity Validity,
subject Name,
subjectPublicKeyInfo SubjectPublicKeyInfo,
issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
-- If present, version must be v2 or v3
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
-- If present, version must be v2 or v3
extensions [3] EXPLICIT Extensions OPTIONAL
-- If present, version must be v3
}
Certificates are instantiated using a certificate factory. The following is an example of how to instantiate an X.509 certificate:
try (InputStream inStream = new FileInputStream("fileName-of-cert")) {
CertificateFactory cf = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate)cf.generateCertificate(inStream);
}
Certificate,
CertificateFactory,
X509Extension,
Serialized Form| Modifier | Constructor and Description |
|---|---|
protected |
X509Certificate()
Constructor for X.509 certificates.
|