* 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 {@code 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);
* }
*
*
* @author Hemma Prafullchandra
*
*
* @see Certificate
* @see CertificateFactory
* @see X509Extension
*/
public abstract class X509Certificate extends Certificate
implements X509Extension {
private static final long serialVersionUID = -2491127588187038216L;
private transient X500Principal subjectX500Principal, issuerX500Principal;
/**
* Constructor for X.509 certificates.
*/
protected X509Certificate() {
super("X.509");
}
/**
* Checks 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 }
*
*
* @exception CertificateExpiredException if the certificate has expired.
* @exception CertificateNotYetValidException if the certificate is not
* yet valid.
*/
public abstract void checkValidity()
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.
*
* @param date the Date to check against to see if this certificate
* is valid at that date/time.
*
* @exception CertificateExpiredException if the certificate has expired
* with respect to the {@code date} supplied.
* @exception CertificateNotYetValidException if the certificate is not
* yet valid with respect to the {@code date} supplied.
*
* @see #checkValidity()
*/
public abstract void checkValidity(Date date)
throws CertificateExpiredException, CertificateNotYetValidException;
/**
* Gets the {@code 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) }
*
* @return the version number, i.e. 1, 2 or 3.
*/
public abstract int getVersion();
/**
* Gets the {@code 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
*
*
* @return the serial number.
*/
public abstract BigInteger getSerialNumber();
/**
* Denigrated, replaced by {@linkplain
* #getIssuerX500Principal()}. This method returns the {@code issuer}
* as an implementation specific Principal object, which should not be
* relied upon by portable code.
*
* * Gets the {@code 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 ::= ANY
*
* The {@code Name} describes a hierarchical name composed of
* attributes,
* such as country name, and corresponding values, such as US.
* The type of the {@code AttributeValue} component is determined by
* the {@code AttributeType}; in general it will be a
* {@code directoryString}. A {@code directoryString} is usually
* one of {@code PrintableString},
* {@code TeletexString} or {@code UniversalString}.
*
* @return a Principal whose name is the issuer distinguished name.
*/
public abstract Principal getIssuerDN();
/**
* Returns the issuer (issuer distinguished name) value from the
* certificate as an {@code X500Principal}.
* * It is recommended that subclasses override this method. * * @return an {@code X500Principal} representing the issuer * distinguished name * @since 1.4 */ public X500Principal getIssuerX500Principal() { if (issuerX500Principal == null) { issuerX500Principal = X509CertImpl.getIssuerX500Principal(this); } return issuerX500Principal; } /** * Denigrated, replaced by {@linkplain * #getSubjectX500Principal()}. This method returns the {@code subject} * as an implementation specific Principal object, which should not be * relied upon by portable code. * *
* Gets the {@code subject} (subject distinguished name) value * from the certificate. If the {@code subject} value is empty, * then the {@code getName()} method of the returned * {@code Principal} object returns an empty string (""). * *
The ASN.1 definition for this is: *
* subject Name
*
*
* See {@link #getIssuerDN() getIssuerDN} for {@code Name} * and other relevant definitions. * * @return a Principal whose name is the subject name. */ public abstract Principal getSubjectDN(); /** * Returns the subject (subject distinguished name) value from the * certificate as an {@code X500Principal}. If the subject value * is empty, then the {@code getName()} method of the returned * {@code X500Principal} object returns an empty string (""). *
* It is recommended that subclasses override this method. * * @return an {@code X500Principal} representing the subject * distinguished name * @since 1.4 */ public X500Principal getSubjectX500Principal() { if (subjectX500Principal == null) { subjectX500Principal = X509CertImpl.getSubjectX500Principal(this); } return subjectX500Principal; } /** * Gets the {@code 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 }
*
*
* @return the start date of the validity period.
* @see #checkValidity
*/
public abstract Date getNotBefore();
/**
* Gets the {@code notAfter} date from the validity period of
* the certificate. See {@link #getNotBefore() getNotBefore}
* for relevant ASN.1 definitions.
*
* @return the end date of the validity period.
* @see #checkValidity
*/
public abstract Date getNotAfter();
/**
* Gets the DER-encoded certificate information, the
* {@code tbsCertificate} from this certificate.
* This can be used to verify the signature independently.
*
* @return the DER-encoded certificate information.
* @exception CertificateEncodingException if an encoding error occurs.
*/
public abstract byte[] getTBSCertificate()
throws CertificateEncodingException;
/**
* Gets the {@code signature} value (the raw signature bits) from
* the certificate.
* The ASN.1 definition for this is:
*
* signature BIT STRING
*
*
* @return the signature.
*/
public abstract byte[] getSignature();
/**
* 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 {@code algorithm} * OID string. * * @return the signature algorithm name. */ public abstract String getSigAlgName(); /** * 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 {@link #getSigAlgName() getSigAlgName} for * relevant ASN.1 definitions. * * @return the signature algorithm OID string. */ public abstract String getSigAlgOID(); /** * 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 use * {@link java.security.AlgorithmParameters AlgorithmParameters} * and instantiate with the name returned by * {@link #getSigAlgName() getSigAlgName}. * *
See {@link #getSigAlgName() getSigAlgName} for * relevant ASN.1 definitions. * * @return the DER-encoded signature algorithm parameters, or * null if no parameters are present. */ public abstract byte[] getSigAlgParams(); /** * Gets the {@code 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 3280 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
*
*
* @return the issuer unique identifier or null if it is not
* present in the certificate.
*/
public abstract boolean[] getIssuerUniqueID();
/**
* Gets the {@code subjectUniqueID} value from the certificate.
*
* The ASN.1 definition for this is: *
* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL
* UniqueIdentifier ::= BIT STRING
*
*
* @return the subject unique identifier or null if it is not
* present in the certificate.
*/
public abstract boolean[] getSubjectUniqueID();
/**
* Gets a boolean array representing bits of
* the {@code 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 3280 recommends that when used, this be marked
* as a critical extension.
*
* @return 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.
*/
public abstract boolean[] getKeyUsage();
/**
* Gets an unmodifiable list of Strings representing the OBJECT
* IDENTIFIERs of the {@code 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 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 {@code abstract}
* and it provides a default implementation. Subclasses
* should override this method with a correct implementation.
*
* @return 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
*/
public List
* 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
* {@code pathLenConstraint} field (see below) is meaningful
* only if {@code 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:
*
* The ASN.1 definition of the {@code SubjectAltName} extension is:
*
* If this certificate does not contain a {@code SubjectAltName}
* extension, {@code null} is returned. Otherwise, a
* {@code Collection} is returned with an entry representing each
* {@code GeneralName} included in the extension. Each entry is a
* {@code List} whose first entry is an {@code Integer}
* (the name type, 0-8) and whose second entry is a {@code 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 {@code String}s,
* using the well-established string formats for those types (subject to
* the restrictions included in RFC 3280). 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 {@code 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 {@code Collection} returned may contain more
* than one name of the same type. Also, note that the returned
* {@code 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 {@code abstract}
* and it provides a default implementation. Subclasses
* should override this method with a correct implementation.
*
* @return an immutable {@code Collection} of subject alternative
* names (or {@code null})
* @throws CertificateParsingException if the extension cannot be decoded
* @since 1.4
*/
public Collection
* The ASN.1 definition of the {@code IssuerAltName} extension is:
*
* If this certificate does not contain an {@code IssuerAltName}
* extension, {@code null} is returned. Otherwise, a
* {@code Collection} is returned with an entry representing each
* {@code GeneralName} included in the extension. Each entry is a
* {@code List} whose first entry is an {@code Integer}
* (the name type, 0-8) and whose second entry is a {@code 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 {@code getSubjectAlternativeNames} method.
*
* Note that the {@code Collection} returned may contain more
* than one name of the same type. Also, note that the returned
* {@code 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 {@code abstract}
* and it provides a default implementation. Subclasses
* should override this method with a correct implementation.
*
* @return an immutable {@code Collection} of issuer alternative
* names (or {@code null})
* @throws CertificateParsingException if the extension cannot be decoded
* @since 1.4
*/
public Collection
* BasicConstraints ::= SEQUENCE {
* cA BOOLEAN DEFAULT FALSE,
* pathLenConstraint INTEGER (0..MAX) OPTIONAL }
*
*
* @return the value of {@code 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
* {@code pathLenConstraint} does not appear,
* {@code Integer.MAX_VALUE} is returned to indicate that there is no
* limit to the allowed length of the certification path.
*/
public abstract int getBasicConstraints();
/**
* Gets an immutable collection of subject alternative names from the
* {@code SubjectAltName} extension, (OID = 2.5.29.17).
*
* 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}
*
*
* IssuerAltName ::= GeneralNames
*
* The ASN.1 definition of {@code GeneralNames} is defined
* in {@link #getSubjectAlternativeNames getSubjectAlternativeNames}.
*