Apple Developer Connection Student Program/ADC Tools Sampler CD Disk 3 1999.iso/Metrowerks CodeWarrior/Java Support/Java_Source/Java2/src/java/security/UnresolvedPermission.java

Java Source | 1999-05-28 | 12.9 KB | 432 lines | [TEXT/CWIE]

/*
 * @(#)UnresolvedPermission.java    1.13 98/09/15
 *
 * Copyright 1997, 1998 by Sun Microsystems, Inc.,
 * 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information
 * of Sun Microsystems, Inc. ("Confidential Information").  You
 * shall not disclose such Confidential Information and shall use
 * it only in accordance with the terms of the license agreement
 * you entered into with Sun.
 */

package java.security;

import java.io.IOException;
import java.io.ByteArrayInputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import java.lang.reflect.*;
import java.security.cert.*;

/**
 * The UnresolvedPermission class is used to hold Permissions that
 * were "unresolved" when the Policy was initialized.
 * An unresolved permission is one whose actual Permission class
 * does not yet exist at the time the Policy is initialized (see below).
 *
 * <p>The policy for a Java runtime (specifying
 * which permissions are available for code from various principals)
 * is represented by a Policy object.
 * Whenever a Policy is initialized or refreshed, Permission objects of
 * appropriate classes are created for all permissions
 * allowed by the Policy.
 *
 * <p>Many permission class types
 * referenced by the policy configuration are ones that exist
 * locally (i.e., ones that can be found on CLASSPATH).
 * Objects for such permissions can be instantiated during
 * Policy initialization. For example, it is always possible
 * to instantiate a java.io.FilePermission, since the
 * FilePermission class is found on the CLASSPATH.
 *
 * <p>Other permission classes may not yet exist during Policy
 * initialization. For example, a referenced permission class may
 * be in a JAR file that will later be loaded.
 * For each such class, an UnresolvedPermission is instantiated.
 * Thus, an UnresolvedPermission is essentially a "placeholder"
 * containing information about the permission.
 *
 * <p>Later, when code calls AccessController.checkPermission
 * on a permission of a type that was previously unresolved,
 * but whose class has since been loaded, previously-unresolved
 * permissions of that type are "resolved". That is,
 * for each such UnresolvedPermission, a new object of
 * the appropriate class type is instantiated, based on the
 * information in the UnresolvedPermission. This new object
 * replaces the UnresolvedPermission, which is removed.
 *
 * @see java.security.Permission
 * @see java.security.Permissions
 * @see java.security.PermissionCollection
 * @see java.security.Policy
 *
 * @version 1.13 99/03/26
 *
 * @author Roland Schemers
 */

public final class UnresolvedPermission extends Permission
implements java.io.Serializable
{
    /**
     * The class name of the Permission class that will be
     * created when this unresolved permission is resolved.
     *
     * @serial
     */
    private String type;

    /**
     * The permission name.
     *
     * @serial
     */
    private String name;

    /**
     * The actions of the permission.
     *
     * @serial
     */
    private String actions;

    private transient java.security.cert.Certificate certs[];

    /**
     * Creates a new UnresolvedPermission containing the permission
     * information needed later to actually create a Permission of the
     * specified class, when the permission is resolved.
     *
     * @param type the class name of the Permission class that will be
     * created when this unresolved permission is resolved.
     * @param name the name of the permission.
     * @param actions the actions of the permission.
     * @param certs the certificates the permission's class was signed with.
     * This is a list of certificate chains, where each chain is composed of a
     * signer certificate and optionally its supporting certificate chain.
     * Each chain is ordered bottom-to-top (i.e., with the signer certificate
     * first and the (root) certificate authority last).
     */
    public UnresolvedPermission(String type,
                String name,
                String actions,
                java.security.cert.Certificate certs[])
    {
    super(type);
    this.type = type;
    this.name = name;
    this.actions = actions;
    if (certs != null) {
        // Extract the signer certs from the list of certificates.
        for (int i=0; i<certs.length; i++) {
        if (!(certs[i] instanceof X509Certificate)) {
            // there is no concept of signer certs, so we store the
            // entire cert array
            this.certs =
            (java.security.cert.Certificate[])certs.clone();
            break;
        }
        }

        if (this.certs == null) {
        // Go through the list of certs and see if all the certs are
        // signer certs.
        int i = 0;
        int count = 0;
        while (i < certs.length) {
            count++;
            while (((i+1) < certs.length) &&
               ((X509Certificate)certs[i]).getIssuerDN().equals(
                       ((X509Certificate)certs[i+1]).getSubjectDN())) {
            i++;
            }
            i++;
        }
        if (count == certs.length) {
            // All the certs are signer certs, so we store the entire
            // array
            this.certs =
            (java.security.cert.Certificate[])certs.clone();
        }

        if (this.certs == null) {
            // extract the signer certs
            ArrayList signerCerts = new ArrayList();
            i = 0;
            while (i < certs.length) {
            signerCerts.add(certs[i]);
            while (((i+1) < certs.length) &&
                ((X509Certificate)certs[i]).getIssuerDN().equals(
                           ((X509Certificate)certs[i+1]).getSubjectDN())) {
                i++;
            }
            i++;
            }
            this.certs =
            new java.security.cert.Certificate[signerCerts.size()];
            signerCerts.toArray(this.certs);
        }
        }
    }
    }


    private static final Class[] PARAMS = { String.class, String.class};

    /**
     * try and resolve this permission using the class loader of the permission
     * that was passed in.
     */
    Permission resolve(Permission p, java.security.cert.Certificate certs[]) {
    if (this.certs != null) {
        // if p wasn't signed, we don't have a match
        if (certs == null) {
        return null;
        }

        // all certs in this.certs must be present in certs
        boolean match;
        for (int i = 0; i < this.certs.length; i++) {
        match = false;
        for (int j = 0; j < certs.length; j++) {
            if (this.certs[i].equals(certs[j])) {
            match = true;
            break;
            }
        }
        if (!match) return null;
        }
    }
    try {
        Class pc = p.getClass();
        Constructor c = pc.getConstructor(PARAMS);
        return (Permission) c.newInstance(new Object[] { name, actions });
    } catch (Exception e) {
        return null;
    }
    }

    /**
     * This method always returns false for unresolved permissions.
     * That is, an UnresolvedPermission is never considered to
     * imply another permission.
     *
     * @param p the permission to check against.
     *
     * @return false.
     */
    public boolean implies(Permission p) {
    return false;
    }

    /**
     * Checks two UnresolvedPermission objects for equality.
     * Checks that <i>obj</i> is an UnresolvedPermission, and has
     * the same type (class) name, permission name, actions, and
     * certificates as this object.
     *
     * @param obj the object we are testing for equality with this object.
     *
     * @return true if obj is an UnresolvedPermission, and has the same
     * type (class) name, permission name, actions, and
     * certificates as this object.
     */
    public boolean equals(Object obj) {
    if (obj == this)
        return true;

    if (! (obj instanceof UnresolvedPermission))
        return false;
    UnresolvedPermission that = (UnresolvedPermission) obj;

    if (!(this.type.equals(that.type) &&
        this.name.equals(that.name) &&
        this.actions.equals(that.actions)))
        return false;

    if (this.certs.length != that.certs.length)
        return false;

    int i,j;
    boolean match;

    for (i = 0; i < this.certs.length; i++) {
        match = false;
        for (j = 0; j < that.certs.length; j++) {
        if (this.certs[i].equals(that.certs[j])) {
            match = true;
            break;
        }
        }
        if (!match) return false;
    }

    for (i = 0; i < that.certs.length; i++) {
        match = false;
        for (j = 0; j < this.certs.length; j++) {
        if (that.certs[i].equals(this.certs[j])) {
            match = true;
            break;
        }
        }
        if (!match) return false;
    }
    return true;
    }

    /**
     * Returns the hash code value for this object.
     *
     * @return a hash code value for this object.
     */

    public int hashCode() {
    int hash = type.hashCode();
    if (name != null)
        hash ^= name.hashCode();
    if (actions != null)
        hash ^= actions.hashCode();
    return hash;
    }

    /**
     * Returns the canonical string representation of the actions,
     * which currently is the empty string "", since there are no actions for
     * an UnresolvedPermission. That is, the actions for the
     * permission that will be created when this UnresolvedPermission
     * is resolved may be non-null, but an UnresolvedPermission
     * itself is never considered to have any actions.
     *
     * @return the empty string "".
     */
    public String getActions()
    {
    return "";
    }

    /**
     * Returns a string describing this UnresolvedPermission.  The convention
     * is to specify the class name, the permission name, and the actions, in
     * the following format: '(unresolved "ClassName" "name" "actions")'.
     *
     * @return information about this UnresolvedPermission.
     */
    public String toString() {
    return "(unresolved " + type + " " + name + " " + actions + ")";
    }

    /**
     * Returns a new PermissionCollection object for storing
     * UnresolvedPermission  objects.
     * <p>
     * @return a new PermissionCollection object suitable for
     * storing UnresolvedPermissions.
     */

    public PermissionCollection newPermissionCollection() {
    return new UnresolvedPermissionCollection();
    }

    /**
     * Writes this object out to a stream (i.e., serializes it).
     *
     * @serialData An initial <code>String</code> denoting the
     * <code>type</code> is followed by a <code>String</code> denoting the
     * <code>name</code> is followed by a <code>String</code> denoting the
     * <code>actions</code> is followed by an <code>int</code> indicating the
     * number of certificates to follow
     * (a value of "zero" denotes that there are no certificates associated
     * with this object).
     * Each certificate is written out starting with a <code>String</code>
     * denoting the certificate type, followed by an
     * <code>int</code> specifying the length of the certificate encoding,
     * followed by the certificate encoding itself which is written out as an
     * array of bytes.
     */
    private synchronized void writeObject(java.io.ObjectOutputStream oos)
        throws IOException
    {
    oos.defaultWriteObject();

    if (certs==null || certs.length==0) {
        oos.writeInt(0);
    } else {
        // write out the total number of certs
        oos.writeInt(certs.length);
        // write out each cert, including its type
        for (int i=0; i < certs.length; i++) {
        java.security.cert.Certificate cert = certs[i];
        try {
            oos.writeUTF(cert.getType());
            byte[] encoded = cert.getEncoded();
            oos.writeInt(encoded.length);
            oos.write(encoded);
        } catch (CertificateEncodingException cee) {
            throw new IOException(cee.getMessage());
        }
        }
    }
    }

    /**
     * Restores this object from a stream (i.e., deserializes it).
     */
    private synchronized void readObject(java.io.ObjectInputStream ois)
    throws IOException, ClassNotFoundException
    {
    CertificateFactory cf;
    Hashtable cfs=null;

    ois.defaultReadObject();

    // process any new-style certs in the stream (if present)
    int size = ois.readInt();
    if (size > 0) {
        // we know of 3 different cert types: X.509, PGP, SDSI, which
        // could all be present in the stream at the same time
        cfs = new Hashtable(3);
        this.certs = new java.security.cert.Certificate[size];
    }

    for (int i=0; i<size; i++) {
        // read the certificate type, and instantiate a certificate
        // factory of that type (reuse existing factory if possible)
        String certType = ois.readUTF();
        if (cfs.containsKey(certType)) {
        // reuse certificate factory
        cf = (CertificateFactory)cfs.get(certType);
        } else {
        // create new certificate factory
        try {
            cf = CertificateFactory.getInstance(certType);
        } catch (CertificateException ce) {
            throw new ClassNotFoundException
            ("Certificate factory for "+certType+" not found");
        }
        // store the certificate factory so we can reuse it later
        cfs.put(certType, cf);
        }
        // parse the certificate
        byte[] encoded=null;
        try {
        encoded = new byte[ois.readInt()];
        } catch (OutOfMemoryError oome) {
        throw new IOException("Certificate too big");
        }
        ois.readFully(encoded);
        ByteArrayInputStream bais = new ByteArrayInputStream(encoded);
        try {
        this.certs[i] = cf.generateCertificate(bais);
        } catch (CertificateException ce) {
        throw new IOException(ce.getMessage());
        }
        bais.close();
    }
    }
}