java.security.cert
Class X509Certificate
java.lang.Object
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+--java.security.cert.Certificate
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+--java.security.cert.X509Certificate
All Implemented Interfaces:
X509Extension
X509Certificate is the abstract class for X.509 certificates.
This provides a stanard class interface for accessing all
the attributes of X.509 certificates.
In June 1996, the basic X.509 v3 format was finished by
ISO/IEC and ANSI X.9. The ASN.1 DER format is below:
Certificate ::= SEQUENCE {
tbsCertificate TBSCertificate,
signatureAlgorithm AlgorithmIdentifier,
signatureValue BIT STRING }
These certificates are widely used in various Internet
protocols to support authentication. It is used in
Privacy Enhanced Mail (PEM), Transport Layer Security (TLS),
Secure Sockets Layer (SSL), code signing for trusted software
distribution, and Secure Electronic Transactions (SET).
The certificates are managed and vouched for by
Certificate Authorities (CAs). CAs are companies or
groups that create certificates by placing the data in the
X.509 certificate format and signing it with their private
key. CAs serve as trusted third parties by certifying that
the person or group specified in the certificate is who
they say they are.
The ASN.1 defintion for 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 shall be v2 or v3
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
-- If present, version shall be v2 or v3
extensions [3] EXPLICIT Extensions OPTIONAL
-- If present, version shall be v3
}
Version ::= INTEGER { v1(0), v2(1), v3(2) }
CertificateSerialNumber ::= INTEGER
Validity ::= SEQUENCE {
notBefore Time,
notAfter Time }
Time ::= CHOICE {
utcTime UTCTime,
generalTime GeneralizedTime }
UniqueIdentifier ::= BIT STRING
SubjectPublicKeyInfo ::= SEQUENCE {
algorithm AlgorithmIdentifier,
subjectPublicKey BIT STRING }
Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
Extension ::= SEQUENCE {
extnID OBJECT IDENTIFIER,
critical BOOLEAN DEFAULT FALSE,
extnValue OCTET STRING }
Certificates are created with the CertificateFactory.
For more information about X.509 certificates, consult
rfc2459.
Since:Author:X509Certificate
protected X509Certificate()
Constructs a new certificate of the specified type.
checkValidity
public void checkValidity()
Checks the validity of the X.509 certificate. It is valid
if the current date and time are within the period specified
by the certificate.
The ASN.1 DER encoding is:
validity Validity,
Validity ::= SEQUENCE {
notBefore Time,
notAfter Time }
Time ::= CHOICE {
utcTime UTCTime,
generalTime GeneralizedTime }
Consult rfc2459 for more information.
Throws:
checkValidity
public void checkValidity(java.util.Date date)
Checks the validity of the X.509 certificate for the
specified time and date. It is valid if the specified
date and time are within the period specified by
the certificate.
Parameters:
Throws:
getBasicConstraints
public int getBasicConstraints()
Returns the certificate constraints path length from the
critical BasicConstraints extension, (OID = 2.5.29.19).
The basic constraints extensions is used to determine if
the subject of the certificate is a Certificate Authority (CA)
and how deep the certification path may exist. The
pathLenConstraint only takes affect if cA
is set to true. "A value of zero indicates that only an
end-entity certificate may follow in the path." (rfc2459)
The ASN.1 DER encoding is:
id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 }
BasicConstraints ::= SEQUENCE {
cA BOOLEAN DEFAULT FALSE,
pathLenConstraint INTEGER (0..MAX) OPTIONAL }
Consult rfc2459 for more information.
Returns:
- the length of the path constraint if BasicConstraints
is present and cA is TRUE. Otherwise returns -1.
getIssuerDN
public Principal getIssuerDN()
Returns the issuer (issuer distinguished name) of the
Certificate. The issuer is the entity who signed
and issued the Certificate.
The ASN.1 DER encoding is:
issuer Name,
Name ::= CHOICE {
RDNSequence }
RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
RelativeDistinguishedName ::=
SET OF AttributeTypeAndValue
AttributeTypeAndValue ::= SEQUENCE {
type AttributeType,
value AttributeValue }
AttributeType ::= OBJECT IDENTIFIER
AttributeValue ::= ANY DEFINED BY AttributeType
DirectoryString ::= CHOICE {
teletexString TeletexString (SIZE (1..MAX)),
printableString PrintableString (SIZE (1..MAX)),
universalString UniversalString (SIZE (1..MAX)),
utf8String UTF8String (SIZE (1.. MAX)),
bmpString BMPString (SIZE (1..MAX)) }
Consult rfc2459 for more information.
Returns:
- the issuer in the Principal class
getIssuerUniqueID
public boolean[] getIssuerUniqueID()
Returns the issuer unique ID for this certificate.
The ASN.1 DER encoding is:
issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
-- If present, version shall be v2 or v3
UniqueIdentifier ::= BIT STRING
Consult rfc2459 for more information.
Returns:
- bit representation of issuerUniqueID
getKeyUsage
public boolean[] getKeyUsage()
Returns a boolean array representing the KeyUsage
extension for the certificate. The KeyUsage (OID = 2.5.29.15)
defines the purpose of the key in the certificate.
The ASN.1 DER encoding is:
id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 }
KeyUsage ::= BIT STRING {
digitalSignature (0),
nonRepudiation (1),
keyEncipherment (2),
dataEncipherment (3),
keyAgreement (4),
keyCertSign (5),
cRLSign (6),
encipherOnly (7),
decipherOnly (8) }
Consult rfc2459 for more information.
Returns:
- bit representation of KeyUsage
getNotAfter
public Date getNotAfter()
Returns the date that this certificate is not to be used
after, notAfter.
Returns:
getNotBefore
public Date getNotBefore()
Returns the date that this certificate is not to be used
before, notBefore.
The ASN.1 DER encoding is:
validity Validity,
Validity ::= SEQUENCE {
notBefore Time,
notAfter Time }
Time ::= CHOICE {
utcTime UTCTime,
generalTime GeneralizedTime }
Consult rfc2459 for more information.
Returns:
getSerialNumber
public BigInteger getSerialNumber()
Gets the serial number for serial Number in
this Certifcate. It must be a unique number
unique other serial numbers from the granting CA.
The ASN.1 DER encoding is:
serialNumber CertificateSerialNumber,
CertificateSerialNumber ::= INTEGER
Consult rfc2459 for more information.
Returns:
- the serial number for this X509CRLEntry.
getSigAlgName
public String getSigAlgName()
Returns the signature algorithm used to sign the CRL.
An examples is "SHA-1/DSA".
The ASN.1 DER encoding is:
signatureAlgorithm AlgorithmIdentifier,
AlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER,
parameters ANY DEFINED BY algorithm OPTIONAL }
Consult rfc2459 for more information.
The algorithm name is determined from the OID.
Returns:
- a string with the signature algorithm name
getSigAlgOID
public String getSigAlgOID()
Returns the OID for the signature algorithm used.
Example "1.2.840.10040.4.3" is return for SHA-1 with DSA.\
The ASN.1 DER encoding for the example is:
id-dsa-with-sha1 ID ::= {
iso(1) member-body(2) us(840) x9-57 (10040)
x9cm(4) 3 }
Consult rfc2459 for more information.
Returns:
- a string containing the OID.
getSigAlgParams
public byte[] getSigAlgParams()
Returns the AlgorithmParameters in the encoded form
for the signature algorithm used.
If access to the parameters is need, create an
instance of AlgorithmParameters.
Returns:
- byte array containing algorithm parameters, null
if no parameters are present in certificate
getSignature
public byte[] getSignature()
Returns the signature in its raw DER encoded format.
The ASN.1 DER encoding is:
signatureValue BIT STRING
Consult rfc2459 for more information.
Returns:
- byte array representing signature
getSubjectDN
public Principal getSubjectDN()
Returns the subject (subject distinguished name) of the
Certificate. The subject is the entity who the Certificate
identifies.
The ASN.1 DER encoding is:
subject Name,
Consult rfc2459 for more information.
Returns:
- the issuer in the Principal class
getSubjectUniqueID
public boolean[] getSubjectUniqueID()
Returns the subject unique ID for this certificate.
The ASN.1 DER encoding is:
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
-- If present, version shall be v2 or v3
UniqueIdentifier ::= BIT STRING
Consult rfc2459 for more information.
Returns:
- bit representation of subjectUniqueID
getTBSCertificate
public byte[] getTBSCertificate()
Returns the tbsCertificate from the certificate.
Returns:
- the DER encoded tbsCertificate
Throws:
getVersion
public int getVersion()
Returns the version of this certificate.
The ASN.1 DER encoding is:
version [0] EXPLICIT Version DEFAULT v1,
Version ::= INTEGER { v1(0), v2(1), v3(2) }
Consult rfc2459 for more information.
Returns:
- version number of certificate