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
- External Specifications
- See Also:
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Nested Class Summary
Nested classes/interfaces declared in class java.security.cert.Certificate
Certificate.CertificateRep -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionabstract voidChecks that the certificate is currently valid.abstract voidcheckValidity(Date date) Checks that the given date is within the certificate's validity period.abstract intGets the certificate constraints path length from the criticalBasicConstraintsextension, (OID = 2.5.29.19).Gets an unmodifiable list of Strings representing the OBJECT IDENTIFIERs of theExtKeyUsageSyntaxfield of the extended key usage extension, (OID = 2.5.29.37).Collection<List<?>> Gets an immutable collection of issuer alternative names from theIssuerAltNameextension, (OID = 2.5.29.18).abstract PrincipalDeprecated.abstract boolean[]Gets theissuerUniqueIDvalue from the certificate.Returns the issuer (issuer distinguished name) value from the certificate as anX500Principal.abstract boolean[]Gets a boolean array representing bits of theKeyUsageextension, (OID = 2.5.29.15).abstract DateGets thenotAfterdate from the validity period of the certificate.abstract DateGets thenotBeforedate from the validity period of the certificate.abstract BigIntegerGets theserialNumbervalue from the certificate.abstract StringGets the signature algorithm name for the certificate signature algorithm.abstract StringGets 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 thesignaturevalue (the raw signature bits) from the certificate.Collection<List<?>> Gets an immutable collection of subject alternative names from theSubjectAltNameextension, (OID = 2.5.29.17).abstract PrincipalDeprecated.UsegetSubjectX500Principal()instead.abstract boolean[]Gets thesubjectUniqueIDvalue from the certificate.Returns the subject (subject distinguished name) value from the certificate as anX500Principal.abstract byte[]Gets the DER-encoded certificate information, thetbsCertificatefrom this certificate.abstract intGets theversion(version number) value from the certificate.voidVerifies 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, writeReplaceMethods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods 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 thedatesupplied.CertificateNotYetValidException- if the certificate is not yet valid with respect to thedatesupplied.- 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 theserialNumbervalue 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 theissueras an implementation specificPrincipalobject, 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 ::= ANYTheNamedescribes a hierarchical name composed of attributes, such as country name, and corresponding values, such as US. The type of theAttributeValuecomponent is determined by theAttributeType; in general it will be adirectoryString. AdirectoryStringis usually one ofPrintableString,TeletexStringorUniversalString.- 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
X500Principalrepresenting the issuer distinguished name - Since:
- 1.4
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getSubjectDN
Deprecated.UsegetSubjectX500Principal()instead. This method returns thesubjectas an implementation specificPrincipalobject, which should not be relied upon by portable code.Gets thesubject(subject distinguished name) value from the certificate. If thesubjectvalue is empty, then thegetName()method of the returnedPrincipalobject returns an empty string ("").The ASN.1 definition for this is:
subject Name
See
getIssuerDNforNameand 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 returnedX500Principalobject returns an empty string ("").It is recommended that subclasses override this method.
- Returns:
- an
X500Principalrepresenting the subject distinguished name - Since:
- 1.4
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getNotBefore
Gets thenotBeforedate 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 thenotAfterdate from the validity period of the certificate. SeegetNotBeforefor 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, thetbsCertificatefrom 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 thesignaturevalue (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 valueThe algorithm name is determined from the
algorithmOID 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
getSigAlgNamefor relevant ASN.1 definitions.- Returns:
- the signature algorithm OID string.
- External Specifications
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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 useAlgorithmParametersand instantiate with the name returned bygetSigAlgName.See
getSigAlgNamefor 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 theissuerUniqueIDvalue 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 thesubjectUniqueIDvalue 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 theKeyUsageextension, (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 theExtKeyUsageSyntaxfield 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
abstractand 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 criticalBasicConstraintsextension, (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
pathLenConstraintfield (see below) is meaningful only ifcAis 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
pathLenConstraintif 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 andpathLenConstraintdoes not appear,Integer.MAX_VALUEis 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 theSubjectAltNameextension, (OID = 2.5.29.17).The ASN.1 definition of the
SubjectAltNameextension 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
SubjectAltNameextension,nullis returned. Otherwise, aCollectionis returned with an entry representing eachGeneralNameincluded in the extension. Each entry is aListwhose first entry is anInteger(the name type, 0-8) and whose second entry is aStringor 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
Strings, 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 asStrings 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-idof the otherName in string form, and a fourth entry containing itsvalueas 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
Collectionreturned may contain more than one name of the same type. Also, note that the returnedCollectionis 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
abstractand 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
Collectionof subject alternative names (ornull) - Throws:
CertificateParsingException- if the extension cannot be decoded- Since:
- 1.4
- External Specifications
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getIssuerAlternativeNames
Gets an immutable collection of issuer alternative names from theIssuerAltNameextension, (OID = 2.5.29.18).The ASN.1 definition of the
IssuerAltNameextension is:IssuerAltName ::= GeneralNames
The ASN.1 definition ofGeneralNamesis defined ingetSubjectAlternativeNames.If this certificate does not contain an
IssuerAltNameextension,nullis returned. Otherwise, aCollectionis returned with an entry representing eachGeneralNameincluded in the extension. Each entry is aListwhose first entry is anInteger(the name type, 0-8) and whose second entry is aStringor 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 thegetSubjectAlternativeNamesmethod.Note that the
Collectionreturned may contain more than one name of the same type. Also, note that the returnedCollectionis 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
abstractand it provides a default implementation. Subclasses should override this method with a correct implementation.- Returns:
- an immutable
Collectionof 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 notabstractand it provides a default implementation.- Overrides:
verifyin 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.