/*

 * Copyright (c) 1996, 2016, 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 sun.security.util;

import java.io.*;

import java.math.BigInteger;

import java.util.Arrays;

/**

 * Represent an ISO Object Identifier.

 *

 * <P>Object Identifiers are arbitrary length hierarchical identifiers.

 * The individual components are numbers, and they define paths from the

 * root of an ISO-managed identifier space.  You will sometimes see a

 * string name used instead of (or in addition to) the numerical id.

 * These are synonyms for the numerical IDs, but are not widely used

 * since most sites do not know all the requisite strings, while all

 * sites can parse the numeric forms.

 *

 * <P>So for example, JavaSoft has the sole authority to assign the

 * meaning to identifiers below the 1.3.6.1.4.1.42.2.17 node in the

 * hierarchy, and other organizations can easily acquire the ability

 * to assign such unique identifiers.

 *

 * @author David Brownell

 * @author Amit Kapoor

 * @author Hemma Prafullchandra

 */

public final

class ObjectIdentifier implements Serializable

{

    /**

     * We use the DER value (no tag, no length) as the internal format

     * @serial

     */

    private byte[] encoding = null;

    private transient volatile String stringForm;

    /*

     * IMPORTANT NOTES FOR CODE CHANGES (bug 4811968) IN JDK 1.7.0

     * ===========================================================

     *

     * (Almost) serialization compatibility with old versions:

     *

     * serialVersionUID is unchanged. Old field "component" is changed to

     * type Object so that "poison" (unknown object type for old versions)

     * can be put inside if there are huge components that cannot be saved

     * as integers.

     *

     * New version use the new filed "encoding" only.

     *

     * Below are all 4 cases in a serialization/deserialization process:

     *

     * 1. old -> old: Not covered here

     * 2. old -> new: There's no "encoding" field, new readObject() reads

     *    "components" and "componentLen" instead and inits correctly.

     * 3. new -> new: "encoding" field exists, new readObject() uses it

     *    (ignoring the other 2 fields) and inits correctly.

     * 4. new -> old: old readObject() only recognizes "components" and

     *    "componentLen" fields. If no huge components are involved, they

     *    are serialized as legal values and old object can init correctly.

     *    Otherwise, old object cannot recognize the form (component not int[])

     *    and throw a ClassNotFoundException at deserialization time.

     *

     * Therfore, for the first 3 cases, exact compatibility is preserved. In

     * the 4th case, non-huge OID is still supportable in old versions, while

     * huge OID is not.

     */

    private static final long serialVersionUID = 8697030238860181294L;

    /**

     * Changed to Object

     * @serial

     */

    private Object      components   = null;          // path from root

    /**

     * @serial

     */

    private int         componentLen = -1;            // how much is used.

    // Is the components field calculated?

    private transient boolean   componentsCalculated = false;

    private void readObject(ObjectInputStream is)

            throws IOException, ClassNotFoundException {

        is.defaultReadObject();

        if (encoding == null) {  // from an old version

            init((int[])components, componentLen);

        }

    }

    private void writeObject(ObjectOutputStream os)

            throws IOException {

        if (!componentsCalculated) {

            int[] comps = toIntArray();

            if (comps != null) {    // every one understands this

                components = comps;

                componentLen = comps.length;

            } else {

                components = HugeOidNotSupportedByOldJDK.theOne;

            }

            componentsCalculated = true;

        }

        os.defaultWriteObject();

    }

    static class HugeOidNotSupportedByOldJDK implements Serializable {

        private static final long serialVersionUID = 1L;

        static HugeOidNotSupportedByOldJDK theOne = new HugeOidNotSupportedByOldJDK();

    }

    /**

     * Constructs, from a string.  This string should be of the form 1.23.56.

     * Validity check included.

     */

    public ObjectIdentifier (String oid) throws IOException

    {

        int ch = '.';

        int start = 0;

        int end = 0;

        int pos = 0;

        byte[] tmp = new byte[oid.length()];

        int first = 0, second;

        int count = 0;

        try {

            String comp = null;

            do {

                int length = 0; // length of one section

                end = oid.indexOf(ch,start);

                if (end == -1) {

                    comp = oid.substring(start);

                    length = oid.length() - start;

                } else {

                    comp = oid.substring(start,end);

                    length = end - start;

                }

                if (length > 9) {

                    BigInteger bignum = new BigInteger(comp);

                    if (count == 0) {

                        checkFirstComponent(bignum);

                        first = bignum.intValue();

                    } else {

                        if (count == 1) {

                            checkSecondComponent(first, bignum);

                            bignum = bignum.add(BigInteger.valueOf(40*first));

                        } else {

                            checkOtherComponent(count, bignum);

                        }

                        pos += pack7Oid(bignum, tmp, pos);

                    }

                } else {

                    int num = Integer.parseInt(comp);

                    if (count == 0) {

                        checkFirstComponent(num);

                        first = num;

                    } else {

                        if (count == 1) {

                            checkSecondComponent(first, num);

                            num += 40 * first;

                        } else {

                            checkOtherComponent(count, num);

                        }

                        pos += pack7Oid(num, tmp, pos);

                    }

                }

                start = end + 1;

                count++;

            } while (end != -1);

            checkCount(count);

            encoding = new byte[pos];

            System.arraycopy(tmp, 0, encoding, 0, pos);

            this.stringForm = oid;

        } catch (IOException ioe) { // already detected by checkXXX

            throw ioe;

        } catch (Exception e) {

            throw new IOException("ObjectIdentifier() -- Invalid format: "

                    + e.toString(), e);

        }

    }

    /**

     * Constructor, from an array of integers.

     * Validity check included.

     */

    public ObjectIdentifier(int[] values) throws IOException

    {

        checkCount(values.length);

        checkFirstComponent(values[0]);

        checkSecondComponent(values[0], values[1]);

        for (int i=2; i<values.length; i++)

            checkOtherComponent(i, values[i]);

        init(values, values.length);

    }

    /**

     * Constructor, from an ASN.1 encoded input stream.

     * Validity check NOT included.

     * The encoding of the ID in the stream uses "DER", a BER/1 subset.

     * In this case, that means a triple { typeId, length, data }.

     *

     * <P><STRONG>NOTE:</STRONG>  When an exception is thrown, the

     * input stream has not been returned to its "initial" state.

     *

     * @param in DER-encoded data holding an object ID

     * @exception IOException indicates a decoding error

     */

    public ObjectIdentifier (DerInputStream in) throws IOException

    {

        byte    type_id;

        int     bufferEnd;

        /*

         * Object IDs are a "universal" type, and their tag needs only

         * one byte of encoding.  Verify that the tag of this datum

         * is that of an object ID.

         *

         * Then get and check the length of the ID's encoding.  We set

         * up so that we can use in.available() to check for the end of

         * this value in the data stream.

         */

        type_id = (byte) in.getByte ();

        if (type_id != DerValue.tag_ObjectId)

            throw new IOException (

                "ObjectIdentifier() -- data isn't an object ID"

                + " (tag = " +  type_id + ")"

                );

        in.getBytes(encoding);

        check(encoding);

    }

    /*

     * Constructor, from the rest of a DER input buffer;

     * the tag and length have been removed/verified

     * Validity check NOT included.

     */

    ObjectIdentifier (DerInputBuffer buf) throws IOException

    {

        DerInputStream in = new DerInputStream(buf);

        encoding = new byte[in.available()];

        in.getBytes(encoding);

        check(encoding);

    }

    private void init(int[] components, int length) {

        int pos = 0;

        byte[] tmp = new byte[length*5+1];  // +1 for empty input

        if (components[1] < Integer.MAX_VALUE - components[0]*40)

            pos += pack7Oid(components[0]*40+components[1], tmp, pos);

        else {

            BigInteger big = BigInteger.valueOf(components[1]);

            big = big.add(BigInteger.valueOf(components[0]*40));

            pos += pack7Oid(big, tmp, pos);

        }

        for (int i=2; i<length; i++) {

            pos += pack7Oid(components[i], tmp, pos);

        }

        encoding = new byte[pos];

        System.arraycopy(tmp, 0, encoding, 0, pos);

    }

    /**

     * This method is kept for compatibility reasons. The new implementation

     * does the check and conversion. All around the JDK, the method is called

     * in static blocks to initialize pre-defined ObjectIdentifieies. No

     * obvious performance hurt will be made after this change.

     *

     * Old doc: Create a new ObjectIdentifier for internal use. The values are

     * neither checked nor cloned.

     */

    public static ObjectIdentifier newInternal(int[] values) {

        try {

            return new ObjectIdentifier(values);

        } catch (IOException ex) {

            throw new RuntimeException(ex);

            // Should not happen, internal calls always uses legal values.

        }

    }

    /*

     * n.b. the only public interface is DerOutputStream.putOID()

     */

    void encode (DerOutputStream out) throws IOException

    {

        out.write (DerValue.tag_ObjectId, encoding);

    }

    /**

     * Compares this identifier with another, for equality.

     *

     * @return true iff the names are identical.

     */

    @Override

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (obj instanceof ObjectIdentifier == false) {

            return false;

        }

        ObjectIdentifier other = (ObjectIdentifier)obj;

        return Arrays.equals(encoding, other.encoding);

    }

    @Override

    public int hashCode() {

        return Arrays.hashCode(encoding);

    }

    /**

     * Private helper method for serialization. To be compatible with old

     * versions of JDK.

     * @return components in an int array, if all the components are less than

     *         Integer.MAX_VALUE. Otherwise, null.

     */

    private int[] toIntArray() {

        int length = encoding.length;

        int[] result = new int[20];

        int which = 0;

        int fromPos = 0;

        for (int i = 0; i < length; i++) {

            if ((encoding[i] & 0x80) == 0) {

                // one section [fromPos..i]

                if (i - fromPos + 1 > 4) {

                    BigInteger big = new BigInteger(pack(encoding, fromPos, i-fromPos+1, 7, 8));

                    if (fromPos == 0) {

                        result[which++] = 2;

                        BigInteger second = big.subtract(BigInteger.valueOf(80));

                        if (second.compareTo(BigInteger.valueOf(Integer.MAX_VALUE)) == 1) {

                            return null;

                        } else {

                            result[which++] = second.intValue();

                        }

                    } else {

                        if (big.compareTo(BigInteger.valueOf(Integer.MAX_VALUE)) == 1) {

                            return null;

                        } else {

                            result[which++] = big.intValue();

                        }

                    }

                } else {

                    int retval = 0;

                    for (int j = fromPos; j <= i; j++) {

                        retval <<= 7;

                        byte tmp = encoding[j];

                        retval |= (tmp & 0x07f);

                    }

                    if (fromPos == 0) {

                        if (retval < 80) {

                            result[which++] = retval / 40;

                            result[which++] = retval % 40;

                        } else {

                            result[which++] = 2;

                            result[which++] = retval - 80;

                        }

                    } else {

                        result[which++] = retval;

                    }

                }

                fromPos = i+1;

            }

            if (which >= result.length) {

                result = Arrays.copyOf(result, which + 10);

            }

        }

        return Arrays.copyOf(result, which);

    }

    /**

     * Returns a string form of the object ID.  The format is the

     * conventional "dot" notation for such IDs, without any

     * user-friendly descriptive strings, since those strings

     * will not be understood everywhere.

     */

    @Override

    public String toString() {

        String s = stringForm;

        if (s == null) {

            int length = encoding.length;

            StringBuilder sb = new StringBuilder(length * 4);

            int fromPos = 0;

            for (int i = 0; i < length; i++) {

                if ((encoding[i] & 0x80) == 0) {

                    // one section [fromPos..i]

                    if (fromPos != 0) {  // not the first segment

                        sb.append('.');

                    }

                    if (i - fromPos + 1 > 4) { // maybe big integer

                        BigInteger big = new BigInteger(pack(encoding, fromPos, i-fromPos+1, 7, 8));

                        if (fromPos == 0) {

                            // first section encoded with more than 4 bytes,

                            // must be 2.something

                            sb.append("2.");

                            sb.append(big.subtract(BigInteger.valueOf(80)));

                        } else {

                            sb.append(big);

                        }

                    } else { // small integer

                        int retval = 0;

                        for (int j = fromPos; j <= i; j++) {

                            retval <<= 7;

                            byte tmp = encoding[j];

                            retval |= (tmp & 0x07f);

                        }

                        if (fromPos == 0) {

                            if (retval < 80) {

                                sb.append(retval/40);

                                sb.append('.');

                                sb.append(retval%40);

                            } else {

                                sb.append("2.");

                                sb.append(retval - 80);

                            }

                        } else {

                            sb.append(retval);

                        }

                    }

                    fromPos = i+1;

                }

            }

            s = sb.toString();

            stringForm = s;

        }

        return s;

    }

    /**

     * Repack all bits from input to output. On the both sides, only a portion

     * (from the least significant bit) of the 8 bits in a byte is used. This

     * number is defined as the number of useful bits (NUB) for the array. All the

     * used bits from the input byte array and repacked into the output in the

     * exactly same order. The output bits are aligned so that the final bit of

     * the input (the least significant bit in the last byte), when repacked as

     * the final bit of the output, is still at the least significant position.

     * Zeroes will be padded on the left side of the first output byte if

     * necessary. All unused bits in the output are also zeroed.

     *

     * For example: if the input is 01001100 with NUB 8, the output which

     * has a NUB 6 will look like:

     *      00000001 00001100

     * The first 2 bits of the output bytes are unused bits. The other bits

     * turn out to be 000001 001100. While the 8 bits on the right are from

     * the input, the left 4 zeroes are padded to fill the 6 bits space.

     *

     * @param in        the input byte array

     * @param ioffset   start point inside <code>in</code>

     * @param ilength   number of bytes to repack

     * @param iw        NUB for input

     * @param ow        NUB for output

     * @return          the repacked bytes

     */

    private static byte[] pack(byte[] in, int ioffset, int ilength, int iw, int ow) {

        assert (iw > 0 && iw <= 8): "input NUB must be between 1 and 8";

        assert (ow > 0 && ow <= 8): "output NUB must be between 1 and 8";

        if (iw == ow) {

            return in.clone();

        }

        int bits = ilength * iw;    // number of all used bits

        byte[] out = new byte[(bits+ow-1)/ow];