Java tutorial
package org.bouncycastle.cert; import java.util.ArrayList; import java.util.List; import org.bouncycastle.asn1.ASN1Encodable; import org.bouncycastle.asn1.x500.X500Name; import org.bouncycastle.asn1.x509.AttCertIssuer; import org.bouncycastle.asn1.x509.GeneralName; import org.bouncycastle.asn1.x509.GeneralNames; import org.bouncycastle.asn1.x509.V2Form; import org.bouncycastle.util.Selector; /** * Carrying class for an attribute certificate issuer. */ public class AttributeCertificateIssuer implements Selector { final ASN1Encodable form; /** * Set the issuer directly with the ASN.1 structure. * * @param issuer The issuer */ public AttributeCertificateIssuer(AttCertIssuer issuer) { form = issuer.getIssuer(); } public AttributeCertificateIssuer(X500Name principal) { form = new V2Form(new GeneralNames(new GeneralName(principal))); } public X500Name[] getNames() { GeneralNames name; if (form instanceof V2Form) { name = ((V2Form) form).getIssuerName(); } else { name = (GeneralNames) form; } GeneralName[] names = name.getNames(); List l = new ArrayList(names.length); for (int i = 0; i != names.length; i++) { if (names[i].getTagNo() == GeneralName.directoryName) { l.add(X500Name.getInstance(names[i].getName())); } } return (X500Name[]) l.toArray(new X500Name[l.size()]); } private boolean matchesDN(X500Name subject, GeneralNames targets) { GeneralName[] names = targets.getNames(); for (int i = 0; i != names.length; i++) { GeneralName gn = names[i]; if (gn.getTagNo() == GeneralName.directoryName) { if (X500Name.getInstance(gn.getName()).equals(subject)) { return true; } } } return false; } public Object clone() { return new AttributeCertificateIssuer(AttCertIssuer.getInstance(form)); } public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof AttributeCertificateIssuer)) { return false; } AttributeCertificateIssuer other = (AttributeCertificateIssuer) obj; return this.form.equals(other.form); } public int hashCode() { return this.form.hashCode(); } public boolean match(Object obj) { if (!(obj instanceof X509CertificateHolder)) { return false; } X509CertificateHolder x509Cert = (X509CertificateHolder) obj; if (form instanceof V2Form) { V2Form issuer = (V2Form) form; if (issuer.getBaseCertificateID() != null) { return issuer.getBaseCertificateID().getSerial().hasValue(x509Cert.getSerialNumber()) && matchesDN(x509Cert.getIssuer(), issuer.getBaseCertificateID().getIssuer()); } GeneralNames name = issuer.getIssuerName(); if (matchesDN(x509Cert.getSubject(), name)) { return true; } } else { GeneralNames name = (GeneralNames) form; if (matchesDN(x509Cert.getSubject(), name)) { return true; } } return false; } }