/*

 * Copyright 1997-2002 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.security.x509;

import java.io.IOException;

import java.lang.Integer;

import java.net.InetAddress;

import java.util.Arrays;

import sun.misc.HexDumpEncoder;

import sun.security.util.BitArray;

import sun.security.util.DerOutputStream;

import sun.security.util.DerValue;

/**

 * This class implements the IPAddressName as required by the GeneralNames

 * ASN.1 object.  Both IPv4 and IPv6 addresses are supported using the

 * formats specified in IETF PKIX RFC2459.

 * <p>

 * [RFC2459 4.2.1.7 Subject Alternative Name]

 * When the subjectAltName extension contains a iPAddress, the address

 * MUST be stored in the octet string in "network byte order," as

 * specified in RFC 791. The least significant bit (LSB) of

 * each octet is the LSB of the corresponding byte in the network

 * address. For IP Version 4, as specified in RFC 791, the octet string

 * MUST contain exactly four octets.  For IP Version 6, as specified in

 * RFC 1883, the octet string MUST contain exactly sixteen octets.

 * <p>

 * [RFC2459 4.2.1.11 Name Constraints]

 * The syntax of iPAddress MUST be as described in section 4.2.1.7 with

 * the following additions specifically for Name Constraints.  For IPv4

 * addresses, the ipAddress field of generalName MUST contain eight (8)

 * octets, encoded in the style of RFC 1519 (CIDR) to represent an

 * address range.[RFC 1519]  For IPv6 addresses, the ipAddress field

 * MUST contain 32 octets similarly encoded.  For example, a name

 * constraint for "class C" subnet 10.9.8.0 shall be represented as the

 * octets 0A 09 08 00 FF FF FF 00, representing the CIDR notation

 * 10.9.8.0/255.255.255.0.

 * <p>

 * @see GeneralName

 * @see GeneralNameInterface

 * @see GeneralNames

 *

 *

 * @author Amit Kapoor

 * @author Hemma Prafullchandra

 */

public class IPAddressName implements GeneralNameInterface {

    private byte[] address;

    private boolean isIPv4;

    private String name;

    /**

     * Create the IPAddressName object from the passed encoded Der value.

     *

     * @params derValue the encoded DER IPAddressName.

     * @exception IOException on error.

     */

    public IPAddressName(DerValue derValue) throws IOException {

        this(derValue.getOctetString());

    }

    /**

     * Create the IPAddressName object with the specified octets.

     *

     * @params address the IP address

     * @throws IOException if address is not a valid IPv4 or IPv6 address

     */

    public IPAddressName(byte[] address) throws IOException {

        /*

         * A valid address must consist of 4 bytes of address and

         * optional 4 bytes of 4 bytes of mask, or 16 bytes of address

         * and optional 16 bytes of mask.

         */

        if (address.length == 4 || address.length == 8) {

            isIPv4 = true;

        } else if (address.length == 16 || address.length == 32) {

            isIPv4 = false;

        } else {

            throw new IOException("Invalid IPAddressName");

        }

        this.address = address;

    }

    /**

     * Create an IPAddressName from a String.

     * [IETF RFC1338 Supernetting & IETF RFC1519 Classless Inter-Domain

     * Routing (CIDR)] For IPv4 addresses, the forms are

     * "b1.b2.b3.b4" or "b1.b2.b3.b4/m1.m2.m3.m4", where b1 - b4 are decimal

     * byte values 0-255 and m1 - m4 are decimal mask values

     * 0 - 255.

     * <p>

     * [IETF RFC2373 IP Version 6 Addressing Architecture]

     * For IPv6 addresses, the forms are "a1:a2:...:a8" or "a1:a2:...:a8/n",

     * where a1-a8 are hexadecimal values representing the eight 16-bit pieces

     * of the address. If /n is used, n is a decimal number indicating how many

     * of the leftmost contiguous bits of the address comprise the prefix for

     * this subnet. Internally, a mask value is created using the prefix length.

     * <p>

     * @param name String form of IPAddressName

     * @throws IOException if name can not be converted to a valid IPv4 or IPv6

     *     address

     */

    public IPAddressName(String name) throws IOException {

        if (name == null || name.length() == 0) {

            throw new IOException("IPAddress cannot be null or empty");

        }

        if (name.charAt(name.length() - 1) == '/') {

            throw new IOException("Invalid IPAddress: " + name);

        }

        if (name.indexOf(':') >= 0) {

            // name is IPv6: uses colons as value separators

            // Parse name into byte-value address components and optional

            // prefix

            parseIPv6(name);

            isIPv4 = false;

        } else if (name.indexOf('.') >= 0) {

            //name is IPv4: uses dots as value separators

            parseIPv4(name);

            isIPv4 = true;

        } else {

            throw new IOException("Invalid IPAddress: " + name);

        }

    }

    /**

     * Parse an IPv4 address.

     *

     * @param name IPv4 address with optional mask values

     * @throws IOException on error

     */

    private void parseIPv4(String name) throws IOException {

        // Parse name into byte-value address components

        int slashNdx = name.indexOf('/');

        if (slashNdx == -1) {

            address = InetAddress.getByName(name).getAddress();

        } else {

            address = new byte[8];

            // parse mask

            byte[] mask = InetAddress.getByName

                (name.substring(slashNdx+1)).getAddress();

            // parse base address

            byte[] host = InetAddress.getByName

                (name.substring(0, slashNdx)).getAddress();

            System.arraycopy(host, 0, address, 0, 4);

            System.arraycopy(mask, 0, address, 4, 4);

        }

    }

    /**

     * Parse an IPv6 address.

     *

     * @param name String IPv6 address with optional /<prefix length>

     *             If /<prefix length> is present, address[] array will

     *             be 32 bytes long, otherwise 16.

     * @throws IOException on error

     */

    private final static int MASKSIZE = 16;

    private void parseIPv6(String name) throws IOException {

        int slashNdx = name.indexOf('/');

        if (slashNdx == -1) {

            address = InetAddress.getByName(name).getAddress();

        } else {

            address = new byte[32];

            byte[] base = InetAddress.getByName

                (name.substring(0, slashNdx)).getAddress();

            System.arraycopy(base, 0, address, 0, 16);

            // append a mask corresponding to the num of prefix bits specified

            int prefixLen = Integer.parseInt(name.substring(slashNdx+1));

            if (prefixLen > 128)

                throw new IOException("IPv6Address prefix is longer than 128");

            // create new bit array initialized to zeros

            BitArray bitArray = new BitArray(MASKSIZE * 8);

            // set all most significant bits up to prefix length

            for (int i = 0; i < prefixLen; i++)

                bitArray.set(i, true);

            byte[] maskArray = bitArray.toByteArray();

            // copy mask bytes into mask portion of address

            for (int i = 0; i < MASKSIZE; i++)

                address[MASKSIZE+i] = maskArray[i];

        }

    }

    /**

     * Return the type of the GeneralName.

     */

    public int getType() {

        return NAME_IP;

    }

    /**

     * Encode the IPAddress name into the DerOutputStream.

     *

     * @params out the DER stream to encode the IPAddressName to.

     * @exception IOException on encoding errors.

     */

    public void encode(DerOutputStream out) throws IOException {

        out.putOctetString(address);

    }

    /**

     * Return a printable string of IPaddress

     */

    public String toString() {

        try {

            return "IPAddress: " + getName();

        } catch (IOException ioe) {

            // dump out hex rep for debugging purposes

            HexDumpEncoder enc = new HexDumpEncoder();

            return "IPAddress: " + enc.encodeBuffer(address);

        }

    }

    /**

     * Return a standard String representation of IPAddress.

     * See IPAddressName(String) for the formats used for IPv4

     * and IPv6 addresses.

     *

     * @throws IOException if the IPAddress cannot be converted to a String

     */

    public String getName() throws IOException {

        if (name != null)

            return name;

        if (isIPv4) {

            //IPv4 address or subdomain

            byte[] host = new byte[4];

            System.arraycopy(address, 0, host, 0, 4);

            name = InetAddress.getByAddress(host).getHostAddress();

            if (address.length == 8) {

                byte[] mask = new byte[4];

                System.arraycopy(address, 4, mask, 0, 4);

                name = name + "/" +

                       InetAddress.getByAddress(mask).getHostAddress();

            }

        } else {

            //IPv6 address or subdomain

            byte[] host = new byte[16];

            System.arraycopy(address, 0, host, 0, 16);

            name = InetAddress.getByAddress(host).getHostAddress();

            if (address.length == 32) {

                // IPv6 subdomain: display prefix length

                // copy subdomain into new array and convert to BitArray

                byte[] maskBytes = new byte[16];

                for (int i=16; i < 32; i++)

                    maskBytes[i-16] = address[i];

                BitArray ba = new BitArray(16*8, maskBytes);

                // Find first zero bit

                int i=0;

                for (; i < 16*8; i++) {

                    if (!ba.get(i))

                        break;

                }

                name = name + "/" + i;

                // Verify remaining bits 0

                for (; i < 16*8; i++) {

                    if (ba.get(i)) {

                        throw new IOException("Invalid IPv6 subdomain - set " +

                            "bit " + i + " not contiguous");

                    }

                }

            }

        }

        return name;

    }

    /**

     * Returns this IPAddress name as a byte array.

     */

    public byte[] getBytes() {

        return address.clone();

    }

    /**

     * Compares this name with another, for equality.

     *

     * @return true iff the names are identical.

     */

    public boolean equals(Object obj) {

        if (this == obj)

            return true;

        if (!(obj instanceof IPAddressName))

            return false;

        byte[] other = ((IPAddressName)obj).getBytes();

        if (other.length != address.length)

            return false;

        if (address.length == 8 || address.length == 32) {

            // Two subnet addresses

            // Mask each and compare masked values

            int maskLen = address.length/2;

            byte[] maskedThis = new byte[maskLen];

            byte[] maskedOther = new byte[maskLen];

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

                maskedThis[i] = (byte)(address[i] & address[i+maskLen]);

                maskedOther[i] = (byte)(other[i] & other[i+maskLen]);

                if (maskedThis[i] != maskedOther[i]) {

                    return false;

                }

            }

            // Now compare masks

            for (int i=maskLen; i < address.length; i++)

                if (address[i] != other[i])

                    return false;

            return true;

        } else {

            // Two IPv4 host addresses or two IPv6 host addresses

            // Compare bytes

            return Arrays.equals(other, address);

        }

    }

    /**

     * Returns the hash code value for this object.

     *

     * @return a hash code value for this object.

     */

    public int hashCode() {

        int retval = 0;

        for (int i=0; i<address.length; i++)

            retval += address[i] * i;

        return retval;

    }

    /**

     * Return type of constraint inputName places on this name:<ul>

     *   <li>NAME_DIFF_TYPE = -1: input name is different type from name

     *       (i.e. does not constrain).

     *   <li>NAME_MATCH = 0: input name matches name.

     *   <li>NAME_NARROWS = 1: input name narrows name (is lower in the naming

     *       subtree)

     *   <li>NAME_WIDENS = 2: input name widens name (is higher in the naming

     *       subtree)

     *   <li>NAME_SAME_TYPE = 3: input name does not match or narrow name, but

     *       is same type.

     * </ul>.  These results are used in checking NameConstraints during

     * certification path verification.

     * <p>

     * [RFC2459] The syntax of iPAddress MUST be as described in section

     * 4.2.1.7 with the following additions specifically for Name Constraints.

     * For IPv4 addresses, the ipAddress field of generalName MUST contain

     * eight (8) octets, encoded in the style of RFC 1519 (CIDR) to represent an

     * address range.[RFC 1519]  For IPv6 addresses, the ipAddress field

     * MUST contain 32 octets similarly encoded.  For example, a name

     * constraint for "class C" subnet 10.9.8.0 shall be represented as the

     * octets 0A 09 08 00 FF FF FF 00, representing the CIDR notation

     * 10.9.8.0/255.255.255.0.

     * <p>

     * @param inputName to be checked for being constrained

     * @returns constraint type above

     * @throws UnsupportedOperationException if name is not exact match, but

     * narrowing and widening are not supported for this name type.

     */

    public int constrains(GeneralNameInterface inputName)

    throws UnsupportedOperationException {

        int constraintType;

        if (inputName == null)

            constraintType = NAME_DIFF_TYPE;

        else if (inputName.getType() != NAME_IP)

            constraintType = NAME_DIFF_TYPE;

        else if (((IPAddressName)inputName).equals(this))

            constraintType = NAME_MATCH;

        else {

            byte[] otherAddress = ((IPAddressName)inputName).getBytes();

            if (otherAddress.length == 4 && address.length == 4)

                // Two host addresses

                constraintType = NAME_SAME_TYPE;

            else if ((otherAddress.length == 8 && address.length == 8) ||

                     (otherAddress.length == 32 && address.length == 32)) {

                // Two subnet addresses

                // See if one address fully encloses the other address

                boolean otherSubsetOfThis = true;

                boolean thisSubsetOfOther = true;

                boolean thisEmpty = false;

                boolean otherEmpty = false;

                int maskOffset = address.length/2;

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

                    if ((byte)(address[i] & address[i+maskOffset]) != address[i])

                        thisEmpty=true;

                    if ((byte)(otherAddress[i] & otherAddress[i+maskOffset]) != otherAddress[i])

                        otherEmpty=true;

                    if (!(((byte)(address[i+maskOffset] & otherAddress[i+maskOffset]) == address[i+maskOffset]) &&

                          ((byte)(address[i]   & address[i+maskOffset])      == (byte)(otherAddress[i] & address[i+maskOffset])))) {

                        otherSubsetOfThis = false;

                    }

                    if (!(((byte)(otherAddress[i+maskOffset] & address[i+maskOffset])      == otherAddress[i+maskOffset]) &&

                          ((byte)(otherAddress[i]   & otherAddress[i+maskOffset]) == (byte)(address[i] & otherAddress[i+maskOffset])))) {

                        thisSubsetOfOther = false;

                    }

                }

                if (thisEmpty || otherEmpty) {

                    if (thisEmpty && otherEmpty)

                        constraintType = NAME_MATCH;

                    else if (thisEmpty)

                        constraintType = NAME_WIDENS;

                    else

                        constraintType = NAME_NARROWS;

                } else if (otherSubsetOfThis)

                    constraintType = NAME_NARROWS;

                else if (thisSubsetOfOther)

                    constraintType = NAME_WIDENS;

                else

                    constraintType = NAME_SAME_TYPE;

            } else if (otherAddress.length == 8 || otherAddress.length == 32) {

                //Other is a subnet, this is a host address

                int i = 0;

                int maskOffset = otherAddress.length/2;

                for (; i < maskOffset; i++) {

                    // Mask this address by other address mask and compare to other address

                    // If all match, then this address is in other address subnet

                    if ((address[i] & otherAddress[i+maskOffset]) != otherAddress[i])

                        break;

                }

                if (i == maskOffset)

                    constraintType = NAME_WIDENS;

                else

                    constraintType = NAME_SAME_TYPE;

            } else if (address.length == 8 || address.length == 32) {

                //This is a subnet, other is a host address

                int i = 0;

                int maskOffset = address.length/2;

                for (; i < maskOffset; i++) {

                    // Mask other address by this address mask and compare to this address

                    if ((otherAddress[i] & address[i+maskOffset]) != address[i])

                        break;

                }

                if (i == maskOffset)

                    constraintType = NAME_NARROWS;

                else

                    constraintType = NAME_SAME_TYPE;

            } else {

                constraintType = NAME_SAME_TYPE;

            }

        }

        return constraintType;

    }

    /**

     * Return subtree depth of this name for purposes of determining

     * NameConstraints minimum and maximum bounds and for calculating

     * path lengths in name subtrees.

     *

     * @returns distance of name from root

     * @throws UnsupportedOperationException if not supported for this name type

     */

    public int subtreeDepth() throws UnsupportedOperationException {

        throw new UnsupportedOperationException

            ("subtreeDepth() not defined for IPAddressName");

    }

}