src/java.base/share/classes/sun/security/x509/CertificatePoliciesExtension.java

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package sun.security.x509;

import java.io.IOException;
import java.util.*;

import sun.security.util.DerValue;
import sun.security.util.DerOutputStream;

/**
 * This class defines the certificate policies extension which specifies the
 * policies under which the certificate has been issued
 * and the purposes for which the certificate may be used.
 * <p>
 * Applications with specific policy requirements are expected to have a
 * list of those policies which they will accept and to compare the
 * policy OIDs in the certificate to that list.  If this extension is
 * critical, the path validation software MUST be able to interpret this
 * extension (including the optional qualifier), or MUST reject the
 * certificate.
 * <p>
 * Optional qualifiers are not supported in this implementation, as they are
 * not recommended by RFC 5280.
 *
 * The ASN.1 syntax for this is (IMPLICIT tagging is defined in the
 * module definition):
 * <pre>
 * id-ce-certificatePolicies OBJECT IDENTIFIER ::=  { id-ce 32 }
 *
 * certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
 *
 * PolicyInformation ::= SEQUENCE {
 *      policyIdentifier   CertPolicyId,
 *      policyQualifiers   SEQUENCE SIZE (1..MAX) OF
 *                              PolicyQualifierInfo OPTIONAL }
 *
 * CertPolicyId ::= OBJECT IDENTIFIER
 * </pre>
 * @author Anne Anderson
 * @since       1.4
 * @see Extension
 */
public class CertificatePoliciesExtension extends Extension {

    public static final String NAME = "CertificatePolicies";

    /**
     * List of PolicyInformation for this object.
     */
    private List<PolicyInformation> certPolicies;

    // Encode this extension value.
    private void encodeThis() {
        if (certPolicies == null || certPolicies.isEmpty()) {
            this.extensionValue = null;
        } else {
            DerOutputStream os = new DerOutputStream();
            DerOutputStream tmp = new DerOutputStream();

            for (PolicyInformation info : certPolicies) {
                info.encode(tmp);
            }

            os.write(DerValue.tag_Sequence, tmp);
            this.extensionValue = os.toByteArray();
        }
    }

    /**
     * Create a CertificatePoliciesExtension object from
     * a List of PolicyInformation; the criticality is set to false.
     *
     * @param certPolicies the List of PolicyInformation.
     */
    public CertificatePoliciesExtension(List<PolicyInformation> certPolicies) {
        this(Boolean.FALSE, certPolicies);
    }

    /**
     * Create a CertificatePoliciesExtension object from
     * a List of PolicyInformation with specified criticality.
     *
     * @param critical true if the extension is to be treated as critical.
     * @param certPolicies the List of PolicyInformation, cannot be null or empty.
     */
    public CertificatePoliciesExtension(Boolean critical,
            List<PolicyInformation> certPolicies) {
        if (certPolicies == null || certPolicies.isEmpty()) {
            throw new IllegalArgumentException(
                    "certificate policies cannot be null or empty");
        }
        this.certPolicies = certPolicies;
        this.extensionId = PKIXExtensions.CertificatePolicies_Id;
        this.critical = critical.booleanValue();
        encodeThis();
    }

    /**
     * Create the extension from its DER encoded value and criticality.
     *
     * @param critical true if the extension is to be treated as critical.
     * @param value an array of DER encoded bytes of the actual value.
     * @exception ClassCastException if value is not an array of bytes
     * @exception IOException on error.
     */
    public CertificatePoliciesExtension(Boolean critical, Object value)
    throws IOException {
        this.extensionId = PKIXExtensions.CertificatePolicies_Id;
        this.critical = critical.booleanValue();
        this.extensionValue = (byte[]) value;
        DerValue val = new DerValue(this.extensionValue);
        if (val.tag != DerValue.tag_Sequence) {
            throw new IOException("Invalid encoding for " +
                                   "CertificatePoliciesExtension.");
        }
        certPolicies = new ArrayList<>();
        while (val.data.available() != 0) {
            DerValue seq = val.data.getDerValue();
            PolicyInformation policy = new PolicyInformation(seq);
            certPolicies.add(policy);
        }
    }

    /**
     * Return the extension as user readable string.
     */
    public String toString() {
        if (certPolicies == null) {
            return "";
        }

        StringBuilder sb = new StringBuilder();
        sb.append(super.toString())
            .append("CertificatePolicies [\n");
        for (PolicyInformation info : certPolicies) {
            sb.append(info);
        }
        sb.append("]\n");
        return sb.toString();
    }

    /**
     * Write the extension to the DerOutputStream.
     *
     * @param out the DerOutputStream to write the extension to.
     */
    @Override
    public void encode(DerOutputStream out) {
        if (extensionValue == null) {
          extensionId = PKIXExtensions.CertificatePolicies_Id;
          critical = false;
          encodeThis();
        }
        super.encode(out);
    }

    /**
     * Get the PolicyInformation value.
     */
    public List<PolicyInformation> getCertPolicies() {
        return certPolicies;
    }



    /**
     * Return the name of this extension.
     */
    @Override
    public String getName() {
        return NAME;
    }
}