Serializable
, X509Extension
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 5280: 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 FormCertificate.CertificateRep
Modifier | Constructor | Description |
---|---|---|
protected |
X509Certificate() |
Constructor for X.509 certificates.
|
Modifier and Type | Method | Description |
---|---|---|
abstract void |
checkValidity() |
Checks that the certificate is currently valid.
|
abstract void |
checkValidity(Date date) |
Checks that the given date is within the certificate's
validity period.
|
abstract int |
getBasicConstraints() |
Gets the certificate constraints path length from the
critical
BasicConstraints extension, (OID = 2.5.29.19). |
List<String> |
getExtendedKeyUsage() |
Gets an unmodifiable list of Strings representing the OBJECT
IDENTIFIERs of the
ExtKeyUsageSyntax field of the
extended key usage extension, (OID = 2.5.29.37). |
Collection<List<?>> |
getIssuerAlternativeNames() |
Gets an immutable collection of issuer alternative names from the
IssuerAltName extension, (OID = 2.5.29.18). |
abstract Principal |
getIssuerDN() |
Denigrated, replaced by getIssuerX500Principal().
|
abstract boolean[] |
getIssuerUniqueID() |
Gets the
issuerUniqueID value from the certificate. |
X500Principal |
getIssuerX500Principal() |
Returns the issuer (issuer distinguished name) value from the
certificate as an
X500Principal . |
abstract boolean[] |
getKeyUsage() |
Gets a boolean array representing bits of
the
KeyUsage extension, (OID = 2.5.29.15). |
abstract Date |
getNotAfter() |
Gets the
notAfter date from the validity period of
the certificate. |
abstract Date |
getNotBefore() |
Gets the
notBefore date from the validity period of
the certificate. |
abstract BigInteger |
getSerialNumber() |
Gets the
serialNumber value from the certificate. |
abstract String |
getSigAlgName() |
Gets the signature algorithm name for the certificate
signature algorithm.
|
abstract String |
getSigAlgOID() |
Gets the signature algorithm OID string from the certificate.
|
abstract byte[] |
getSigAlgParams() |
Gets the DER-encoded signature algorithm parameters from this
certificate's signature algorithm.
|
abstract byte[] |
getSignature() |
Gets the
signature value (the raw signature bits) from
the certificate. |
Collection<List<?>> |
getSubjectAlternativeNames() |
Gets an immutable collection of subject alternative names from the
SubjectAltName extension, (OID = 2.5.29.17). |
abstract Principal |
getSubjectDN() |
Denigrated, replaced by getSubjectX500Principal().
|
abstract boolean[] |
getSubjectUniqueID() |
Gets the
subjectUniqueID value from the certificate. |
X500Principal |
getSubjectX500Principal() |
Returns the subject (subject distinguished name) value from the
certificate as an
X500Principal . |
abstract byte[] |
getTBSCertificate() |
Gets the DER-encoded certificate information, the
tbsCertificate from this certificate. |
abstract int |
getVersion() |
Gets the
version (version number) value from the
certificate. |
void |
verify(PublicKey key,
Provider sigProvider) |
Verifies that this certificate was signed using the
private key that corresponds to the specified public key.
|
equals, getEncoded, getPublicKey, getType, hashCode, toString, verify, verify, writeReplace
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
getCriticalExtensionOIDs, getExtensionValue, getNonCriticalExtensionOIDs, hasUnsupportedCriticalExtension
public abstract void checkValidity() throws CertificateExpiredException, CertificateNotYetValidException
The validity period consists of two date/time values: the first and last dates (and times) on which the certificate is valid. It is defined in ASN.1 as:
validity Validity Validity ::= SEQUENCE { notBefore CertificateValidityDate, notAfter CertificateValidityDate } CertificateValidityDate ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime }
CertificateExpiredException
- if the certificate has expired.CertificateNotYetValidException
- if the certificate is not
yet valid.public abstract void checkValidity(Date date) throws CertificateExpiredException, CertificateNotYetValidException
date
- the Date to check against to see if this certificate
is valid at that date/time.CertificateExpiredException
- if the certificate has expired
with respect to the date
supplied.CertificateNotYetValidException
- if the certificate is not
yet valid with respect to the date
supplied.checkValidity()
public abstract int getVersion()
version
(version number) value from the
certificate.
The ASN.1 definition for this is:
version [0] EXPLICIT Version DEFAULT v1 Version ::= INTEGER { v1(0), v2(1), v3(2) }
public abstract BigInteger getSerialNumber()
serialNumber
value from the certificate.
The serial number is an integer assigned by the certification
authority to each certificate. It must be unique for each
certificate issued by a given CA (i.e., the issuer name and
serial number identify a unique certificate).
The ASN.1 definition for this is:
serialNumber CertificateSerialNumber CertificateSerialNumber ::= INTEGER
public abstract Principal getIssuerDN()
issuer
as an implementation specific Principal object, which should not be
relied upon by portable code.
Gets the issuer
(issuer distinguished name) value from
the certificate. The issuer name identifies the entity that signed (and
issued) the certificate.
The issuer name field contains an X.500 distinguished name (DN). The ASN.1 definition for this is:
issuer Name Name ::= CHOICE { RDNSequence } RDNSequence ::= SEQUENCE OF RelativeDistinguishedName RelativeDistinguishedName ::= SET OF AttributeValueAssertion AttributeValueAssertion ::= SEQUENCE { AttributeType, AttributeValue } AttributeType ::= OBJECT IDENTIFIER AttributeValue ::= ANYThe
Name
describes a hierarchical name composed of
attributes,
such as country name, and corresponding values, such as US.
The type of the AttributeValue
component is determined by
the AttributeType
; in general it will be a
directoryString
. A directoryString
is usually
one of PrintableString
,
TeletexString
or UniversalString
.public X500Principal getIssuerX500Principal()
X500Principal
.
It is recommended that subclasses override this method.
X500Principal
representing the issuer
distinguished namepublic abstract Principal getSubjectDN()
subject
as an implementation specific Principal object, which should not be
relied upon by portable code.
Gets the subject
(subject distinguished name) value
from the certificate. If the subject
value is empty,
then the getName()
method of the returned
Principal
object returns an empty string ("").
The ASN.1 definition for this is:
subject Name
See getIssuerDN
for Name
and other relevant definitions.
public X500Principal getSubjectX500Principal()
X500Principal
. If the subject value
is empty, then the getName()
method of the returned
X500Principal
object returns an empty string ("").
It is recommended that subclasses override this method.
X500Principal
representing the subject
distinguished namepublic abstract Date getNotBefore()
notBefore
date from the validity period of
the certificate.
The relevant ASN.1 definitions are:
validity Validity Validity ::= SEQUENCE { notBefore CertificateValidityDate, notAfter CertificateValidityDate } CertificateValidityDate ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime }
checkValidity()
public abstract Date getNotAfter()
notAfter
date from the validity period of
the certificate. See getNotBefore
for relevant ASN.1 definitions.checkValidity()
public abstract byte[] getTBSCertificate() throws CertificateEncodingException
tbsCertificate
from this certificate.
This can be used to verify the signature independently.CertificateEncodingException
- if an encoding error occurs.public abstract byte[] getSignature()
signature
value (the raw signature bits) from
the certificate.
The ASN.1 definition for this is:
signature BIT STRING
public abstract String getSigAlgName()
signatureAlgorithm AlgorithmIdentifier AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } -- contains a value of the type -- registered for use with the -- algorithm object identifier value
The algorithm name is determined from the algorithm
OID string.
public abstract String getSigAlgOID()
See getSigAlgName
for
relevant ASN.1 definitions.
public abstract byte[] getSigAlgParams()
AlgorithmParameters
and instantiate with the name returned by
getSigAlgName
.
See getSigAlgName
for
relevant ASN.1 definitions.
public abstract boolean[] getIssuerUniqueID()
issuerUniqueID
value from the certificate.
The issuer unique identifier is present in the certificate
to handle the possibility of reuse of issuer names over time.
RFC 5280 recommends that names not be reused and that
conforming certificates not make use of unique identifiers.
Applications conforming to that profile should be capable of
parsing unique identifiers and making comparisons.
The ASN.1 definition for this is:
issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL UniqueIdentifier ::= BIT STRING
public abstract boolean[] getSubjectUniqueID()
subjectUniqueID
value from the certificate.
The ASN.1 definition for this is:
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL UniqueIdentifier ::= BIT STRING
public abstract boolean[] getKeyUsage()
KeyUsage
extension, (OID = 2.5.29.15).
The key usage extension defines the purpose (e.g., encipherment,
signature, certificate signing) of the key contained in the
certificate.
The ASN.1 definition for this is:
KeyUsage ::= BIT STRING { digitalSignature (0), nonRepudiation (1), keyEncipherment (2), dataEncipherment (3), keyAgreement (4), keyCertSign (5), cRLSign (6), encipherOnly (7), decipherOnly (8) }RFC 5280 recommends that when used, this be marked as a critical extension.
public List<String> getExtendedKeyUsage() throws CertificateParsingException
ExtKeyUsageSyntax
field of the
extended key usage extension, (OID = 2.5.29.37). It indicates
one or more purposes for which the certified public key may be
used, in addition to or in place of the basic purposes
indicated in the key usage extension field. The ASN.1
definition for this is:
ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId KeyPurposeId ::= OBJECT IDENTIFIERKey purposes may be defined by any organization with a need. Object identifiers used to identify key purposes shall be assigned in accordance with IANA or ITU-T Rec. X.660 | ISO/IEC/ITU 9834-1.
This method was added to version 1.4 of the Java 2 Platform Standard
Edition. In order to maintain backwards compatibility with existing
service providers, this method is not abstract
and it provides a default implementation. Subclasses
should override this method with a correct implementation.
CertificateParsingException
- if the extension cannot be decodedpublic abstract int getBasicConstraints()
BasicConstraints
extension, (OID = 2.5.29.19).
The basic constraints extension identifies whether the subject
of the certificate is a Certificate Authority (CA) and
how deep a certification path may exist through that CA. The
pathLenConstraint
field (see below) is meaningful
only if cA
is set to TRUE. In this case, it gives the
maximum number of CA certificates that may follow this certificate in a
certification path. A value of zero indicates that only an end-entity
certificate may follow in the path.
The ASN.1 definition for this is:
BasicConstraints ::= SEQUENCE { cA BOOLEAN DEFAULT FALSE, pathLenConstraint INTEGER (0..MAX) OPTIONAL }
pathLenConstraint
if the
BasicConstraints extension is present in the certificate and the
subject of the certificate is a CA, otherwise -1.
If the subject of the certificate is a CA and
pathLenConstraint
does not appear,
Integer.MAX_VALUE
is returned to indicate that there is no
limit to the allowed length of the certification path.public Collection<List<?>> getSubjectAlternativeNames() throws CertificateParsingException
SubjectAltName
extension, (OID = 2.5.29.17).
The ASN.1 definition of the SubjectAltName
extension is:
SubjectAltName ::= GeneralNames GeneralNames :: = SEQUENCE SIZE (1..MAX) OF GeneralName GeneralName ::= CHOICE { otherName [0] OtherName, rfc822Name [1] IA5String, dNSName [2] IA5String, x400Address [3] ORAddress, directoryName [4] Name, ediPartyName [5] EDIPartyName, uniformResourceIdentifier [6] IA5String, iPAddress [7] OCTET STRING, registeredID [8] OBJECT IDENTIFIER}
If this certificate does not contain a SubjectAltName
extension, null
is returned. Otherwise, a
Collection
is returned with an entry representing each
GeneralName
included in the extension. Each entry is a
List
whose first entry is an Integer
(the name type, 0-8) and whose second entry is a String
or a byte array (the name, in string or ASN.1 DER encoded form,
respectively).
RFC 822, DNS, and URI
names are returned as String
s,
using the well-established string formats for those types (subject to
the restrictions included in RFC 5280). IPv4 address names are
returned using dotted quad notation. IPv6 address names are returned
in the form "a1:a2:...:a8", where a1-a8 are hexadecimal values
representing the eight 16-bit pieces of the address. OID names are
returned as String
s represented as a series of nonnegative
integers separated by periods. And directory names (distinguished names)
are returned in
RFC 2253 string format. No standard string format is
defined for otherNames, X.400 names, EDI party names, or any
other type of names. They are returned as byte arrays
containing the ASN.1 DER encoded form of the name.
Note that the Collection
returned may contain more
than one name of the same type. Also, note that the returned
Collection
is immutable and any entries containing byte
arrays are cloned to protect against subsequent modifications.
This method was added to version 1.4 of the Java 2 Platform Standard
Edition. In order to maintain backwards compatibility with existing
service providers, this method is not abstract
and it provides a default implementation. Subclasses
should override this method with a correct implementation.
Collection
of subject alternative
names (or null
)CertificateParsingException
- if the extension cannot be decodedpublic Collection<List<?>> getIssuerAlternativeNames() throws CertificateParsingException
IssuerAltName
extension, (OID = 2.5.29.18).
The ASN.1 definition of the IssuerAltName
extension is:
IssuerAltName ::= GeneralNamesThe ASN.1 definition of
GeneralNames
is defined
in getSubjectAlternativeNames
.
If this certificate does not contain an IssuerAltName
extension, null
is returned. Otherwise, a
Collection
is returned with an entry representing each
GeneralName
included in the extension. Each entry is a
List
whose first entry is an Integer
(the name type, 0-8) and whose second entry is a String
or a byte array (the name, in string or ASN.1 DER encoded form,
respectively). For more details about the formats used for each
name type, see the getSubjectAlternativeNames
method.
Note that the Collection
returned may contain more
than one name of the same type. Also, note that the returned
Collection
is immutable and any entries containing byte
arrays are cloned to protect against subsequent modifications.
This method was added to version 1.4 of the Java 2 Platform Standard
Edition. In order to maintain backwards compatibility with existing
service providers, this method is not abstract
and it provides a default implementation. Subclasses
should override this method with a correct implementation.
Collection
of issuer alternative
names (or null
)CertificateParsingException
- if the extension cannot be decodedpublic void verify(PublicKey key, Provider sigProvider) throws CertificateException, NoSuchAlgorithmException, InvalidKeyException, SignatureException
abstract
and it provides a default implementation.verify
in class Certificate
key
- the PublicKey used to carry out the verification.sigProvider
- the signature provider.NoSuchAlgorithmException
- on unsupported signature
algorithms.InvalidKeyException
- on incorrect key.SignatureException
- on signature errors.CertificateException
- on encoding errors.UnsupportedOperationException
- if the method is not supported Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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