Class X509Certificate
- All Implemented Interfaces:
Serializable
,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); }
- Since:
- 1.2
- See Also:
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Nested Class Summary
Nested classes/interfaces declared in class java.security.cert.Certificate
Certificate.CertificateRep
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract void
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
Gets the certificate constraints path length from the criticalBasicConstraints
extension, (OID = 2.5.29.19).Gets an unmodifiable list of Strings representing the OBJECT IDENTIFIERs of theExtKeyUsageSyntax
field of the extended key usage extension, (OID = 2.5.29.37).Collection
<List<?>> Gets an immutable collection of issuer alternative names from theIssuerAltName
extension, (OID = 2.5.29.18).abstract Principal
Deprecated.abstract boolean[]
Gets theissuerUniqueID
value from the certificate.Returns the issuer (issuer distinguished name) value from the certificate as anX500Principal
.abstract boolean[]
Gets a boolean array representing bits of theKeyUsage
extension, (OID = 2.5.29.15).abstract Date
Gets thenotAfter
date from the validity period of the certificate.abstract Date
Gets thenotBefore
date from the validity period of the certificate.abstract BigInteger
Gets theserialNumber
value from the certificate.abstract String
Gets the signature algorithm name for the certificate signature algorithm.abstract String
Gets the signature algorithm OID string from the certificate.abstract byte[]
Gets the DER-encoded signature algorithm parameters from this certificate's signature algorithm.abstract byte[]
Gets thesignature
value (the raw signature bits) from the certificate.Collection
<List<?>> Gets an immutable collection of subject alternative names from theSubjectAltName
extension, (OID = 2.5.29.17).abstract Principal
Deprecated.UsegetSubjectX500Principal()
instead.abstract boolean[]
Gets thesubjectUniqueID
value from the certificate.Returns the subject (subject distinguished name) value from the certificate as anX500Principal
.abstract byte[]
Gets the DER-encoded certificate information, thetbsCertificate
from this certificate.abstract int
Gets theversion
(version number) value from the certificate.void
Verifies that this certificate was signed using the private key that corresponds to the specified public key.Methods declared in class java.security.cert.Certificate
equals, getEncoded, getPublicKey, getType, hashCode, toString, verify, verify, writeReplace
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods declared in interface java.security.cert.X509Extension
getCriticalExtensionOIDs, getExtensionValue, getNonCriticalExtensionOIDs, hasUnsupportedCriticalExtension
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Constructor Details
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X509Certificate
protected X509Certificate()Constructor for X.509 certificates.
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Method Details
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checkValidity
public abstract void checkValidity() throws CertificateExpiredException, CertificateNotYetValidExceptionChecks that the certificate is currently valid. It is if the current date and time are within the validity period given in the certificate.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 }
- Throws:
CertificateExpiredException
- if the certificate has expired.CertificateNotYetValidException
- if the certificate is not yet valid.
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checkValidity
public abstract void checkValidity(Date date) throws CertificateExpiredException, CertificateNotYetValidException Checks that the given date is within the certificate's validity period. In other words, this determines whether the certificate would be valid at the given date/time.- Parameters:
date
- the Date to check against to see if this certificate is valid at that date/time.- Throws:
CertificateExpiredException
- if the certificate has expired with respect to thedate
supplied.CertificateNotYetValidException
- if the certificate is not yet valid with respect to thedate
supplied.- See Also:
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getVersion
public abstract int getVersion()Gets theversion
(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) }
- Returns:
- the version number, i.e. 1, 2 or 3.
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getSerialNumber
Gets theserialNumber
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
- Returns:
- the serial number.
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getIssuerDN
Deprecated.UsegetIssuerX500Principal()
instead. This method returns theissuer
as an implementation specificPrincipal
object, which should not be relied upon by portable code.Gets theissuer
(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 ::= ANY
TheName
describes a hierarchical name composed of attributes, such as country name, and corresponding values, such as US. The type of theAttributeValue
component is determined by theAttributeType
; in general it will be adirectoryString
. AdirectoryString
is usually one ofPrintableString
,TeletexString
orUniversalString
.- Returns:
- a Principal whose name is the issuer distinguished name.
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getIssuerX500Principal
Returns the issuer (issuer distinguished name) value from the certificate as anX500Principal
.It is recommended that subclasses override this method.
- Returns:
- an
X500Principal
representing the issuer distinguished name - Since:
- 1.4
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getSubjectDN
Deprecated.UsegetSubjectX500Principal()
instead. This method returns thesubject
as an implementation specificPrincipal
object, which should not be relied upon by portable code.Gets thesubject
(subject distinguished name) value from the certificate. If thesubject
value is empty, then thegetName()
method of the returnedPrincipal
object returns an empty string ("").The ASN.1 definition for this is:
subject Name
See
getIssuerDN
forName
and other relevant definitions.- Returns:
- a Principal whose name is the subject name.
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getSubjectX500Principal
Returns the subject (subject distinguished name) value from the certificate as anX500Principal
. If the subject value is empty, then thegetName()
method of the returnedX500Principal
object returns an empty string ("").It is recommended that subclasses override this method.
- Returns:
- an
X500Principal
representing the subject distinguished name - Since:
- 1.4
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getNotBefore
Gets thenotBefore
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 }
- Returns:
- the start date of the validity period.
- See Also:
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getNotAfter
Gets thenotAfter
date from the validity period of the certificate. SeegetNotBefore
for relevant ASN.1 definitions.- Returns:
- the end date of the validity period.
- See Also:
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getTBSCertificate
Gets the DER-encoded certificate information, thetbsCertificate
from this certificate. This can be used to verify the signature independently.- Returns:
- the DER-encoded certificate information.
- Throws:
CertificateEncodingException
- if an encoding error occurs.
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getSignature
public abstract byte[] getSignature()Gets thesignature
value (the raw signature bits) from the certificate. The ASN.1 definition for this is:signature BIT STRING
- Returns:
- the signature.
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getSigAlgName
Gets the signature algorithm name for the certificate signature algorithm. An example is the string "SHA256withRSA". The ASN.1 definition for this is: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.- Returns:
- the signature algorithm name.
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getSigAlgOID
Gets the signature algorithm OID string from the certificate. An OID is represented by a set of nonnegative whole numbers separated by periods. For example, the string "1.2.840.10040.4.3" identifies the SHA-1 with DSA signature algorithm defined in RFC 3279: Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and CRL Profile.See
getSigAlgName
for relevant ASN.1 definitions.- Returns:
- the signature algorithm OID string.
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getSigAlgParams
public abstract byte[] getSigAlgParams()Gets the DER-encoded signature algorithm parameters from this certificate's signature algorithm. In most cases, the signature algorithm parameters are null; the parameters are usually supplied with the certificate's public key. If access to individual parameter values is needed then useAlgorithmParameters
and instantiate with the name returned bygetSigAlgName
.See
getSigAlgName
for relevant ASN.1 definitions.- Returns:
- the DER-encoded signature algorithm parameters, or null if no parameters are present.
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getIssuerUniqueID
public abstract boolean[] getIssuerUniqueID()Gets theissuerUniqueID
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
- Returns:
- the issuer unique identifier or null if it is not present in the certificate.
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getSubjectUniqueID
public abstract boolean[] getSubjectUniqueID()Gets thesubjectUniqueID
value from the certificate.The ASN.1 definition for this is:
subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL UniqueIdentifier ::= BIT STRING
- Returns:
- the subject unique identifier or null if it is not present in the certificate.
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getKeyUsage
public abstract boolean[] getKeyUsage()Gets a boolean array representing bits of theKeyUsage
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.- Returns:
- the KeyUsage extension of this certificate, represented as an array of booleans. The order of KeyUsage values in the array is the same as in the above ASN.1 definition. The array will contain a value for each KeyUsage defined above. If the KeyUsage list encoded in the certificate is longer than the above list, it will not be truncated. Returns null if this certificate does not contain a KeyUsage extension.
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getExtendedKeyUsage
Gets an unmodifiable list of Strings representing the OBJECT IDENTIFIERs of theExtKeyUsageSyntax
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 IDENTIFIER
Key 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.- Returns:
- the ExtendedKeyUsage extension of this certificate, as an unmodifiable list of object identifiers represented as Strings. Returns null if this certificate does not contain an ExtendedKeyUsage extension.
- Throws:
CertificateParsingException
- if the extension cannot be decoded- Since:
- 1.4
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getBasicConstraints
public abstract int getBasicConstraints()Gets the certificate constraints path length from the criticalBasicConstraints
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 ifcA
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 }
- Returns:
- the value of
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 andpathLenConstraint
does not appear,Integer.MAX_VALUE
is returned to indicate that there is no limit to the allowed length of the certification path.
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getSubjectAlternativeNames
Gets an immutable collection of subject alternative names from theSubjectAltName
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} OtherName ::= SEQUENCE { type-id OBJECT IDENTIFIER, value [0] EXPLICIT ANY DEFINED BY type-id }
If this certificate does not contain a
SubjectAltName
extension,null
is returned. Otherwise, aCollection
is returned with an entry representing eachGeneralName
included in the extension. Each entry is aList
whose first entry is anInteger
(the name type, 0-8) and whose second entry is aString
or a byte array (the name, in string or ASN.1 DER encoded form, respectively). More entries may exist depending on the name type.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 asString
s represented as a series of nonnegative integers separated by periods. Directory names (distinguished names) are returned in RFC 2253 string format. No standard string format is defined for X.400 names or EDI party names. They are returned as byte arrays containing the ASN.1 DER encoded form of the name. otherNames are also returned as byte arrays containing the ASN.1 DER encoded form of the name. A third entry may also be present in the list containing thetype-id
of the otherName in string form, and a fourth entry containing itsvalue
as either a string (if the value is a valid supported character string) or a byte array containing the ASN.1 DER encoded form of the value without the context-specific constructed tag with number 0.Note that the
Collection
returned may contain more than one name of the same type. Also, note that the returnedCollection
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.- Implementation Note:
- The JDK SUN provider supports the third and fourth otherName entries.
- Returns:
- an immutable
Collection
of subject alternative names (ornull
) - Throws:
CertificateParsingException
- if the extension cannot be decoded- Since:
- 1.4
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getIssuerAlternativeNames
Gets an immutable collection of issuer alternative names from theIssuerAltName
extension, (OID = 2.5.29.18).The ASN.1 definition of the
IssuerAltName
extension is:IssuerAltName ::= GeneralNames
The ASN.1 definition ofGeneralNames
is defined ingetSubjectAlternativeNames
.If this certificate does not contain an
IssuerAltName
extension,null
is returned. Otherwise, aCollection
is returned with an entry representing eachGeneralName
included in the extension. Each entry is aList
whose first entry is anInteger
(the name type, 0-8) and whose second entry is aString
or a byte array (the name, in string or ASN.1 DER encoded form, respectively). More entries may exist depending on the name type. For more details about the formats used for each name type, see thegetSubjectAlternativeNames
method.Note that the
Collection
returned may contain more than one name of the same type. Also, note that the returnedCollection
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.- Returns:
- an immutable
Collection
of issuer alternative names (ornull
) - Throws:
CertificateParsingException
- if the extension cannot be decoded- Since:
- 1.4
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verify
public void verify(PublicKey key, Provider sigProvider) throws CertificateException, NoSuchAlgorithmException, InvalidKeyException, SignatureException Verifies that this certificate was signed using the private key that corresponds to the specified public key. This method uses the signature verification engine supplied by the specified provider. Note that the specified Provider object does not have to be registered in the provider list. This method was added to version 1.8 of the Java Platform Standard Edition. In order to maintain backwards compatibility with existing service providers, this method is notabstract
and it provides a default implementation.- Overrides:
verify
in classCertificate
- Parameters:
key
- the PublicKey used to carry out the verification.sigProvider
- the signature provider.- Throws:
NoSuchAlgorithmException
- on unsupported signature algorithms.InvalidKeyException
- on incorrect key.SignatureException
- on signature errors.CertificateException
- on encoding errors.UnsupportedOperationException
- if the method is not supported- Since:
- 1.8
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getIssuerX500Principal()
instead.