/*
 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.jndi.ldap;

import javax.naming.*;
import javax.naming.directory.*;
import javax.naming.spi.DirectoryManager;
import javax.naming.spi.DirStateFactory;

import java.io.IOException;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.InputStream;

import java.util.Hashtable;
import java.util.Vector;
import java.util.StringTokenizer;

import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;

import java.lang.reflect.Proxy;
import java.lang.reflect.Modifier;

Class containing static methods and constants for dealing with
encoding/decoding JNDI References and Serialized Objects
in LDAP.
Author:
Vincent Ryan, Rosanna Lee/**
  * Class containing static methods and constants for dealing with
  * encoding/decoding JNDI References and Serialized Objects
  * in LDAP.
  * @author Vincent Ryan
  * @author Rosanna Lee
  */
final class Obj {

    private Obj () {}; // Make sure no one can create one

    // package private; used by Connection
    static VersionHelper helper = VersionHelper.getVersionHelper();

    // LDAP attributes used to support Java objects.
    static final String[] JAVA_ATTRIBUTES = {
        "objectClass",
        "javaSerializedData",
        "javaClassName",
        "javaFactory",
        "javaCodeBase",
        "javaReferenceAddress",
        "javaClassNames",
        "javaRemoteLocation"     // Deprecated
    };

    static final int OBJECT_CLASS = 0;
    static final int SERIALIZED_DATA = 1;
    static final int CLASSNAME = 2;
    static final int FACTORY = 3;
    static final int CODEBASE = 4;
    static final int REF_ADDR = 5;
    static final int TYPENAME = 6;
    
Deprecated:
/**
     * @deprecated
     */
    @Deprecated
    private static final int REMOTE_LOC = 7;

    // LDAP object classes to support Java objects
    static final String[] JAVA_OBJECT_CLASSES = {
        "javaContainer",
        "javaObject",
        "javaNamingReference",
        "javaSerializedObject",
        "javaMarshalledObject",
    };

    static final String[] JAVA_OBJECT_CLASSES_LOWER = {
        "javacontainer",
        "javaobject",
        "javanamingreference",
        "javaserializedobject",
        "javamarshalledobject",
    };

    static final int STRUCTURAL = 0;    // structural object class
    static final int BASE_OBJECT = 1;   // auxiliary java object class
    static final int REF_OBJECT = 2;    // auxiliary reference object class
    static final int SER_OBJECT = 3;    // auxiliary serialized object class
    static final int MAR_OBJECT = 4;    // auxiliary marshalled object class

    
Encode an object in LDAP attributes.
Supports binding Referenceable or Reference, Serializable,
and DirContext.
If the object supports the Referenceable interface then encode
the reference to the object. See encodeReference() for details.

If the object is serializable, it is stored as follows:
javaClassName
  value: Object.getClass();
javaSerializedData
  value: serialized form of Object (in binary form).
javaTypeName
  value: getTypeNames(Object.getClass());
/**
     * Encode an object in LDAP attributes.
     * Supports binding Referenceable or Reference, Serializable,
     * and DirContext.
     *
     * If the object supports the Referenceable interface then encode
     * the reference to the object. See encodeReference() for details.
     *<p>
     * If the object is serializable, it is stored as follows:
     * javaClassName
     *   value: Object.getClass();
     * javaSerializedData
     *   value: serialized form of Object (in binary form).
     * javaTypeName
     *   value: getTypeNames(Object.getClass());
     */
    private static Attributes encodeObject(char separator,
        Object obj, Attributes attrs,
        Attribute objectClass, boolean cloned)
        throws NamingException {
            boolean structural =
                (objectClass.size() == 0 ||
                    (objectClass.size() == 1 && objectClass.contains("top")));

            if (structural) {
                objectClass.add(JAVA_OBJECT_CLASSES[STRUCTURAL]);
            }

    // References
            if (obj instanceof Referenceable) {
                objectClass.add(JAVA_OBJECT_CLASSES[BASE_OBJECT]);
                objectClass.add(JAVA_OBJECT_CLASSES[REF_OBJECT]);
                if (!cloned) {
                    attrs = (Attributes)attrs.clone();
                }
                attrs.put(objectClass);
                return (encodeReference(separator,
                    ((Referenceable)obj).getReference(),
                    attrs, obj));

            } else if (obj instanceof Reference) {
                objectClass.add(JAVA_OBJECT_CLASSES[BASE_OBJECT]);
                objectClass.add(JAVA_OBJECT_CLASSES[REF_OBJECT]);
                if (!cloned) {
                    attrs = (Attributes)attrs.clone();
                }
                attrs.put(objectClass);
                return (encodeReference(separator, (Reference)obj, attrs, null));

    // Serializable Object
            } else if (obj instanceof java.io.Serializable) {
                objectClass.add(JAVA_OBJECT_CLASSES[BASE_OBJECT]);
                if (!(objectClass.contains(JAVA_OBJECT_CLASSES[MAR_OBJECT]) ||
                    objectClass.contains(JAVA_OBJECT_CLASSES_LOWER[MAR_OBJECT]))) {
                    objectClass.add(JAVA_OBJECT_CLASSES[SER_OBJECT]);
                }
                if (!cloned) {
                    attrs = (Attributes)attrs.clone();
                }
                attrs.put(objectClass);
                attrs.put(new BasicAttribute(JAVA_ATTRIBUTES[SERIALIZED_DATA],
                    serializeObject(obj)));
                if (attrs.get(JAVA_ATTRIBUTES[CLASSNAME]) == null) {
                    attrs.put(JAVA_ATTRIBUTES[CLASSNAME],
                        obj.getClass().getName());
                }
                if (attrs.get(JAVA_ATTRIBUTES[TYPENAME]) == null) {
                    Attribute tAttr =
                        LdapCtxFactory.createTypeNameAttr(obj.getClass());
                    if (tAttr != null) {
                        attrs.put(tAttr);
                    }
                }
    // DirContext Object
            } else if (obj instanceof DirContext) {
                // do nothing
            } else {
                throw new IllegalArgumentException(
            "can only bind Referenceable, Serializable, DirContext");
            }
            //      System.err.println(attrs);
            return attrs;
    }

    
Each value in javaCodebase contains a list of space-separated
URLs. Each value is independent; we can pick any of the values
so we just use the first one.
Returns:
an array of URL strings for the codebase/**
     * Each value in javaCodebase contains a list of space-separated
     * URLs. Each value is independent; we can pick any of the values
     * so we just use the first one.
     * @return an array of URL strings for the codebase
     */
    private static String[] getCodebases(Attribute codebaseAttr) throws
        NamingException {
        if (codebaseAttr == null) {
            return null;
        } else {
            StringTokenizer parser =
                new StringTokenizer((String)codebaseAttr.get());
            Vector<String> vec = new Vector<>(10);
            while (parser.hasMoreTokens()) {
                vec.addElement(parser.nextToken());
            }
            String[] answer = new String[vec.size()];
            for (int i = 0; i < answer.length; i++) {
                answer[i] = vec.elementAt(i);
            }
            return answer;
        }
    }

    /*
     * Decode an object from LDAP attribute(s).
     * The object may be a Reference, or a Serialized object.
     *
     * See encodeObject() and encodeReference() for details on formats
     * expected.
     */
    static Object decodeObject(Attributes attrs)
        throws NamingException {

        Attribute attr;

        // Get codebase, which is used in all 3 cases.
        String[] codebases = getCodebases(attrs.get(JAVA_ATTRIBUTES[CODEBASE]));
        try {
            if ((attr = attrs.get(JAVA_ATTRIBUTES[SERIALIZED_DATA])) != null) {
                ClassLoader cl = helper.getURLClassLoader(codebases);
                return deserializeObject((byte[])attr.get(), cl);
            } else if ((attr = attrs.get(JAVA_ATTRIBUTES[REMOTE_LOC])) != null) {
                // For backward compatibility only
                return decodeRmiObject(
                    (String)attrs.get(JAVA_ATTRIBUTES[CLASSNAME]).get(),
                    (String)attr.get(), codebases);
            }

            attr = attrs.get(JAVA_ATTRIBUTES[OBJECT_CLASS]);
            if (attr != null &&
                (attr.contains(JAVA_OBJECT_CLASSES[REF_OBJECT]) ||
                    attr.contains(JAVA_OBJECT_CLASSES_LOWER[REF_OBJECT]))) {
                return decodeReference(attrs, codebases);
            }
            return null;
        } catch (IOException e) {
            NamingException ne = new NamingException();
            ne.setRootCause(e);
            throw ne;
        }
    }

    
Convert a Reference object into several LDAP attributes.
A Reference is stored as into the following attributes:
javaClassName
  value: Reference.getClassName();
javaFactory
  value: Reference.getFactoryClassName();
javaCodeBase
  value: Reference.getFactoryClassLocation();
javaReferenceAddress
  value: #0#typeA#valA
  value: #1#typeB#valB
  value: #2#typeC##[serialized RefAddr C]
  value: #3#typeD#valD
where
-  the first character denotes the separator
-  the number following the first separator denotes the position
   of the RefAddr within the Reference
-  "typeA" is RefAddr.getType()
-  ## denotes that the Base64-encoded form of the non-StringRefAddr
   is to follow; otherwise the value that follows is
   StringRefAddr.getContents()
The default separator is the hash character (#).
May provide property for this in future.
/**
     * Convert a Reference object into several LDAP attributes.
     *
     * A Reference is stored as into the following attributes:
     * javaClassName
     *   value: Reference.getClassName();
     * javaFactory
     *   value: Reference.getFactoryClassName();
     * javaCodeBase
     *   value: Reference.getFactoryClassLocation();
     * javaReferenceAddress
     *   value: #0#typeA#valA
     *   value: #1#typeB#valB
     *   value: #2#typeC##[serialized RefAddr C]
     *   value: #3#typeD#valD
     *
     * where
     * -  the first character denotes the separator
     * -  the number following the first separator denotes the position
     *    of the RefAddr within the Reference
     * -  "typeA" is RefAddr.getType()
     * -  ## denotes that the Base64-encoded form of the non-StringRefAddr
     *    is to follow; otherwise the value that follows is
     *    StringRefAddr.getContents()
     *
     * The default separator is the hash character (#).
     * May provide property for this in future.
     */

    private static Attributes encodeReference(char separator,
        Reference ref, Attributes attrs, Object orig)
        throws NamingException {

        if (ref == null)
            return attrs;

        String s;

        if ((s = ref.getClassName()) != null) {
            attrs.put(new BasicAttribute(JAVA_ATTRIBUTES[CLASSNAME], s));
        }

        if ((s = ref.getFactoryClassName()) != null) {
            attrs.put(new BasicAttribute(JAVA_ATTRIBUTES[FACTORY], s));
        }

        if ((s = ref.getFactoryClassLocation()) != null) {
            attrs.put(new BasicAttribute(JAVA_ATTRIBUTES[CODEBASE], s));
        }

        // Get original object's types if caller has not explicitly
        // specified other type names
        if (orig != null && attrs.get(JAVA_ATTRIBUTES[TYPENAME]) != null) {
            Attribute tAttr =
                LdapCtxFactory.createTypeNameAttr(orig.getClass());
            if (tAttr != null) {
                attrs.put(tAttr);
            }
        }

        int count = ref.size();

        if (count > 0) {

            Attribute refAttr = new BasicAttribute(JAVA_ATTRIBUTES[REF_ADDR]);
            RefAddr refAddr;
            BASE64Encoder encoder = null;

            for (int i = 0; i < count; i++) {
                refAddr = ref.get(i);

                if (refAddr instanceof StringRefAddr) {
                    refAttr.add(""+ separator + i +
                        separator +     refAddr.getType() +
                        separator + refAddr.getContent());
                } else {
                    if (encoder == null)
                        encoder = new BASE64Encoder();

                    refAttr.add(""+ separator + i +
                        separator + refAddr.getType() +
                        separator + separator +
                        encoder.encodeBuffer(serializeObject(refAddr)));
                }
            }
            attrs.put(refAttr);
        }
        return attrs;
    }

    /*
     * A RMI object is stored in the directory as
     * javaClassName
     *   value: Object.getClass();
     * javaRemoteLocation
     *   value: URL of RMI object (accessed through the RMI Registry)
     * javaCodebase:
     *   value: URL of codebase of where to find classes for object
     *
     * Return the RMI Location URL itself. This will be turned into
     * an RMI object when getObjectInstance() is called on it.
     * %%% Ignore codebase for now. Depend on RMI registry to send code.-RL
     * @deprecated For backward compatibility only
     */
    private static Object decodeRmiObject(String className,
        String rmiName, String[] codebases) throws NamingException {
            return new Reference(className, new StringRefAddr("URL", rmiName));
    }

    /*
     * Restore a Reference object from several LDAP attributes
     */
    private static Reference decodeReference(Attributes attrs,
        String[] codebases) throws NamingException, IOException {

        Attribute attr;
        String className;
        String factory = null;

        if ((attr = attrs.get(JAVA_ATTRIBUTES[CLASSNAME])) != null) {
            className = (String)attr.get();
        } else {
            throw new InvalidAttributesException(JAVA_ATTRIBUTES[CLASSNAME] +
                        " attribute is required");
        }

        if ((attr = attrs.get(JAVA_ATTRIBUTES[FACTORY])) != null) {
            factory = (String)attr.get();
        }

        Reference ref = new Reference(className, factory,
            (codebases != null? codebases[0] : null));

        /*
         * string encoding of a RefAddr is either:
         *
         *      #posn#<type>#<address>
         * or
         *      #posn#<type>##<base64-encoded address>
         */
        if ((attr = attrs.get(JAVA_ATTRIBUTES[REF_ADDR])) != null) {

            String val, posnStr, type;
            char separator;
            int start, sep, posn;
            BASE64Decoder decoder = null;

            ClassLoader cl = helper.getURLClassLoader(codebases);

            /*
             * Temporary Vector for decoded RefAddr addresses - used to ensure
             * unordered addresses are correctly re-ordered.
             */
            Vector<RefAddr> refAddrList = new Vector<>();
            refAddrList.setSize(attr.size());

            for (NamingEnumeration<?> vals = attr.getAll(); vals.hasMore(); ) {

                val = (String)vals.next();

                if (val.length() == 0) {
                    throw new InvalidAttributeValueException(
                        "malformed " + JAVA_ATTRIBUTES[REF_ADDR] + " attribute - "+
                        "empty attribute value");
                }
                // first character denotes encoding separator
                separator = val.charAt(0);
                start = 1;  // skip over separator

                // extract position within Reference
                if ((sep = val.indexOf(separator, start)) < 0) {
                    throw new InvalidAttributeValueException(
                        "malformed " + JAVA_ATTRIBUTES[REF_ADDR] + " attribute - " +
                        "separator '" + separator + "'" + "not found");
                }
                if ((posnStr = val.substring(start, sep)) == null) {
                    throw new InvalidAttributeValueException(
                        "malformed " + JAVA_ATTRIBUTES[REF_ADDR] + " attribute - " +
                        "empty RefAddr position");
                }
                try {
                    posn = Integer.parseInt(posnStr);
                } catch (NumberFormatException nfe) {
                    throw new InvalidAttributeValueException(
                        "malformed " + JAVA_ATTRIBUTES[REF_ADDR] + " attribute - " +
                        "RefAddr position not an integer");
                }
                start = sep + 1; // skip over position and trailing separator

                // extract type
                if ((sep = val.indexOf(separator, start)) < 0) {
                    throw new InvalidAttributeValueException(
                        "malformed " + JAVA_ATTRIBUTES[REF_ADDR] + " attribute - " +
                        "RefAddr type not found");
                }
                if ((type = val.substring(start, sep)) == null) {
                    throw new InvalidAttributeValueException(
                        "malformed " + JAVA_ATTRIBUTES[REF_ADDR] + " attribute - " +
                        "empty RefAddr type");
                }
                start = sep + 1; // skip over type and trailing separator

                // extract content
                if (start == val.length()) {
                    // Empty content
                    refAddrList.setElementAt(new StringRefAddr(type, null), posn);
                } else if (val.charAt(start) == separator) {
                    // Double separators indicate a non-StringRefAddr
                    // Content is a Base64-encoded serialized RefAddr

                    ++start;  // skip over consecutive separator
                    // %%% RL: exception if empty after double separator

                    if (decoder == null)
                        decoder = new BASE64Decoder();

                    RefAddr ra = (RefAddr)
                        deserializeObject(
                            decoder.decodeBuffer(val.substring(start)),
                            cl);

                    refAddrList.setElementAt(ra, posn);
                } else {
                    // Single separator indicates a StringRefAddr
                    refAddrList.setElementAt(new StringRefAddr(type,
                        val.substring(start)), posn);
                }
            }

            // Copy to real reference
            for (int i = 0; i < refAddrList.size(); i++) {
                ref.add(refAddrList.elementAt(i));
            }
        }

        return (ref);
    }

    /*
     * Serialize an object into a byte array
     */
    private static byte[] serializeObject(Object obj) throws NamingException {

        try {
            ByteArrayOutputStream bytes = new ByteArrayOutputStream();
            try (ObjectOutputStream serial = new ObjectOutputStream(bytes)) {
                serial.writeObject(obj);
            }

            return (bytes.toByteArray());

        } catch (IOException e) {
            NamingException ne = new NamingException();
            ne.setRootCause(e);
            throw ne;
        }
    }

    /*
     * Deserializes a byte array into an object.
     */
    private static Object deserializeObject(byte[] obj, ClassLoader cl)
        throws NamingException {

        try {
            // Create ObjectInputStream for deserialization
            ByteArrayInputStream bytes = new ByteArrayInputStream(obj);
            try (ObjectInputStream deserial = cl == null ?
                    new ObjectInputStream(bytes) :
                    new LoaderInputStream(bytes, cl)) {
                return deserial.readObject();
            } catch (ClassNotFoundException e) {
                NamingException ne = new NamingException();
                ne.setRootCause(e);
                throw ne;
            }
        } catch (IOException e) {
            NamingException ne = new NamingException();
            ne.setRootCause(e);
            throw ne;
        }
    }

    
Returns the attributes to bind given an object and its attributes.
/**
      * Returns the attributes to bind given an object and its attributes.
      */
    static Attributes determineBindAttrs(
        char separator, Object obj, Attributes attrs, boolean cloned,
        Name name, Context ctx, Hashtable<?,?> env)
        throws NamingException {

        // Call state factories to convert object and attrs
        DirStateFactory.Result res =
            DirectoryManager.getStateToBind(obj, name, ctx, env, attrs);
        obj = res.getObject();
        attrs = res.getAttributes();

        // We're only storing attributes; no further processing required
        if (obj == null) {
            return attrs;
        }

        //if object to be bound is a DirContext extract its attributes
        if ((attrs == null) && (obj instanceof DirContext)) {
            cloned = true;
            attrs = ((DirContext)obj).getAttributes("");
        }

        boolean ocNeedsCloning = false;

        // Create "objectClass" attribute
        Attribute objectClass;
        if (attrs == null || attrs.size() == 0) {
            attrs = new BasicAttributes(LdapClient.caseIgnore);
            cloned = true;

            // No objectclasses supplied, use "top" to start
            objectClass = new BasicAttribute("objectClass", "top");

        } else {
            // Get existing objectclass attribute
            objectClass = attrs.get("objectClass");
            if (objectClass == null && !attrs.isCaseIgnored()) {
                // %%% workaround
                objectClass = attrs.get("objectclass");
            }

            // No objectclasses supplied, use "top" to start
            if (objectClass == null) {
                objectClass =  new BasicAttribute("objectClass", "top");
            } else if (ocNeedsCloning || !cloned) {
                objectClass = (Attribute)objectClass.clone();
            }
        }

        // convert the supplied object into LDAP attributes
        attrs = encodeObject(separator, obj, attrs, objectClass, cloned);

        // System.err.println("Determined: " + attrs);
        return attrs;
    }

    
An ObjectInputStream that uses a class loader to find classes.
/**
     * An ObjectInputStream that uses a class loader to find classes.
     */
    private static final class LoaderInputStream extends ObjectInputStream {
        private ClassLoader classLoader;

        LoaderInputStream(InputStream in, ClassLoader cl) throws IOException {
            super(in);
            classLoader = cl;
        }

        protected Class<?> resolveClass(ObjectStreamClass desc) throws
                IOException, ClassNotFoundException {
            try {
                // %%% Should use Class.forName(desc.getName(), false, classLoader);
                // except we can't because that is only available on JDK1.2
                return classLoader.loadClass(desc.getName());
            } catch (ClassNotFoundException e) {
                return super.resolveClass(desc);
            }
        }

         protected Class<?> resolveProxyClass(String[] interfaces) throws
                IOException, ClassNotFoundException {
             ClassLoader nonPublicLoader = null;
             boolean hasNonPublicInterface = false;

             // define proxy in class loader of non-public interface(s), if any
             Class<?>[] classObjs = new Class<?>[interfaces.length];
             for (int i = 0; i < interfaces.length; i++) {
                 Class<?> cl = Class.forName(interfaces[i], false, classLoader);
                 if ((cl.getModifiers() & Modifier.PUBLIC) == 0) {
                     if (hasNonPublicInterface) {
                         if (nonPublicLoader != cl.getClassLoader()) {
                             throw new IllegalAccessError(
                                "conflicting non-public interface class loaders");
                         }
                     } else {
                         nonPublicLoader = cl.getClassLoader();
                         hasNonPublicInterface = true;
                     }
                 }
                 classObjs[i] = cl;
             }
             try {
                 return Proxy.getProxyClass(hasNonPublicInterface ?
                        nonPublicLoader : classLoader, classObjs);
             } catch (IllegalArgumentException e) {
                 throw new ClassNotFoundException(null, e);
             }
         }

     }
}