/*

 * Copyright 1997-2000 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 sun.security.util.*;

/**

 * This class implements the RFC822Name as required by the GeneralNames

 * ASN.1 object.

 *

 * @author Amit Kapoor

 * @author Hemma Prafullchandra

 * @see GeneralName

 * @see GeneralNames

 * @see GeneralNameInterface

 */

public class RFC822Name implements GeneralNameInterface

{

    private String name;

    /**

     * Create the RFC822Name object from the passed encoded Der value.

     *

     * @param derValue the encoded DER RFC822Name.

     * @exception IOException on error.

     */

    public RFC822Name(DerValue derValue) throws IOException {

        name = derValue.getIA5String();

        parseName(name);

    }

    /**

     * Create the RFC822Name object with the specified name.

     *

     * @param name the RFC822Name.

     * @throws IOException on invalid input name

     */

    public RFC822Name(String name) throws IOException {

        parseName(name);

        this.name = name;

    }

    /**

     * Parse an RFC822Name string to see if it is a valid

     * addr-spec according to IETF RFC822 and RFC2459:

     * [local-part@]domain

     * <p>

     * local-part@ could be empty for an RFC822Name NameConstraint,

     * but the domain at least must be non-empty.  Case is not

     * significant.

     *

     * @param name the RFC822Name string

     * @throws IOException if name is not valid

     */

    public void parseName(String name) throws IOException {

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

            throw new IOException("RFC822Name may not be null or empty");

        }

        // See if domain is a valid domain name

        String domain = name.substring(name.indexOf('@')+1);

        if (domain.length() == 0) {

            throw new IOException("RFC822Name may not end with @");

        } else {

            //An RFC822 NameConstraint could start with a ., although

            //a DNSName may not

            if (domain.startsWith(".")) {

                if (domain.length() == 1)

                    throw new IOException("RFC822Name domain may not be just .");

            }

        }

    }

    /**

     * Return the type of the GeneralName.

     */

    public int getType() {

        return (GeneralNameInterface.NAME_RFC822);

    }

    /**

     * Return the actual name value of the GeneralName.

     */

    public String getName() {

        return name;

    }

    /**

     * Encode the RFC822 name into the DerOutputStream.

     *

     * @param out the DER stream to encode the RFC822Name to.

     * @exception IOException on encoding errors.

     */

    public void encode(DerOutputStream out) throws IOException {

        out.putIA5String(name);

    }

    /**

     * Convert the name into user readable string.

     */

    public String toString() {

        return ("RFC822Name: " + name);

    }

    /**

     * Compares this name with another, for equality.

     *

     * @return true iff the names are equivalent

     * according to RFC2459.

     */

    public boolean equals(Object obj) {

        if (this == obj)

            return true;

        if (!(obj instanceof RFC822Name))

            return false;

        RFC822Name other = (RFC822Name)obj;

        // RFC2459 mandates that these names are

        // not case-sensitive

        return name.equalsIgnoreCase(other.name);

    }

    /**

     * Returns the hash code value for this object.

     *

     * @return a hash code value for this object.

     */

    public int hashCode() {

        return name.toUpperCase().hashCode();

    }

    /**

     * Return constraint type:<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

     *   <li>NAME_WIDENS = 2: input name widens name

     *   <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]    When the subjectAltName extension contains an Internet mail address,

     * the address MUST be included as an rfc822Name. The format of an

     * rfc822Name is an "addr-spec" as defined in RFC 822 [RFC 822]. An

     * addr-spec has the form "local-part@domain". Note that an addr-spec

     * has no phrase (such as a common name) before it, has no comment (text

     * surrounded in parentheses) after it, and is not surrounded by "<" and

     * ">". Note that while upper and lower case letters are allowed in an

     * RFC 822 addr-spec, no significance is attached to the case.

     * <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() != (GeneralNameInterface.NAME_RFC822)) {

            constraintType = NAME_DIFF_TYPE;

        } else {

            //RFC2459 specifies that case is not significant in RFC822Names

            String inName = (((RFC822Name)inputName).getName()).toLowerCase();

            String thisName = name.toLowerCase();

            if (inName.equals(thisName)) {

                constraintType = NAME_MATCH;

            } else if (thisName.endsWith(inName)) {

                /* if both names contain @, then they had to match exactly */

                if (inName.indexOf('@') != -1) {

                    constraintType = NAME_SAME_TYPE;

                } else if (inName.startsWith(".")) {

                    constraintType = NAME_WIDENS;

                } else {

                    int inNdx = thisName.lastIndexOf(inName);

                    if (thisName.charAt(inNdx-1) == '@' ) {

                        constraintType = NAME_WIDENS;

                    } else {

                        constraintType = NAME_SAME_TYPE;

                    }

                }

            } else if (inName.endsWith(thisName)) {

                /* if thisName contains @, then they had to match exactly */

                if (thisName.indexOf('@') != -1) {

                    constraintType = NAME_SAME_TYPE;

                } else if (thisName.startsWith(".")) {

                    constraintType = NAME_NARROWS;

                } else {

                    int ndx = inName.lastIndexOf(thisName);

                    if (inName.charAt(ndx-1) == '@') {

                        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.

     *

     * @returns distance of name from root

     * @throws UnsupportedOperationException if not supported for this name type

     */

    public int subtreeDepth() throws UnsupportedOperationException {

        String subtree=name;

        int i=1;

        /* strip off name@ portion */

        int atNdx = subtree.lastIndexOf('@');

        if (atNdx >= 0) {

            i++;

            subtree=subtree.substring(atNdx+1);

        }

        /* count dots in dnsname, adding one if dnsname preceded by @ */

        for (; subtree.lastIndexOf('.') >= 0; i++) {

            subtree=subtree.substring(0,subtree.lastIndexOf('.'));

        }

        return i;

    }

}