delete abandoned CryptoHelper class

package com.fsck.k9.crypto;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import com.fsck.k9.mail.Message;

import com.fsck.k9.mail.MessagingException;

import com.fsck.k9.mail.Part;

import com.fsck.k9.mail.internet.MessageExtractor;

import com.fsck.k9.mail.internet.MimeUtility;

public class CryptoHelper {

    public static final Pattern PGP_MESSAGE =

            Pattern.compile(".*?(-----BEGIN PGP MESSAGE-----.*?-----END PGP MESSAGE-----).*",

                    Pattern.DOTALL);

    public static final Pattern PGP_SIGNED_MESSAGE =

            Pattern.compile(

                    ".*?(-----BEGIN PGP SIGNED MESSAGE-----.*?-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----).*",

                    Pattern.DOTALL);

    public CryptoHelper() {

        super();

    }

    /**

     * TODO: use new parseMessage() from PgpUtils to actually parse!

     * @param message

     * @return

     */

    public boolean isEncrypted(Message message) {

        String data = null;

        Part part = MimeUtility.findFirstPartByMimeType(message, "text/plain");

        if (part == null) {

            part = MimeUtility.findFirstPartByMimeType(message, "text/html");

        }

        if (part != null) {

            data = MessageExtractor.getTextFromPart(part);

        }

        if (data == null) {

            return false;

        }

        Matcher matcher = PGP_MESSAGE.matcher(data);

        return matcher.matches();

    }

    public boolean isSigned(Message message) {

        String data = null;

        Part part = MimeUtility.findFirstPartByMimeType(message, "text/plain");

        if (part == null) {

            part = MimeUtility.findFirstPartByMimeType(message, "text/html");

        }

        if (part != null) {

            data = MessageExtractor.getTextFromPart(part);

        }

        if (data == null) {

            return false;

        }

        Matcher matcher = PGP_SIGNED_MESSAGE.matcher(data);

        return matcher.matches();

    }

}