connectbot/sshlib

package com.trilead.ssh2.crypto.digest;

/**
 * MAC.
 *
 * @author Christian Plattner, plattner@trilead.com
 * @version $Id: MAC.java,v 1.1 2007/10/15 12:49:57 cplattne Exp $
 */
public final class MACs
{
    /* Higher Priority First */
    private static final String[] MAC_LIST = {
            HMAC.HMAC_SHA2_256_ETM,
            HMAC.HMAC_SHA2_512_ETM,
            HMAC.HMAC_SHA1_ETM,
            HMAC.HMAC_SHA2_256,
            HMAC.HMAC_SHA2_512,
            HMAC.HMAC_SHA1,
    };

    public final static String[] getMacList()
    {
        return MAC_LIST;
    }

    public final static void checkMacList(String[] macs)
    {
        for (int i = 0; i < macs.length; i++) {
            getKeyLen(macs[i]);
        }
    }

    public final static int getKeyLen(String type)
    {
        if (type == null)
            throw new IllegalArgumentException("type == null");

        if (type.startsWith(HMAC.HMAC_SHA1))
            return 20;
        if (type.startsWith(HMAC.HMAC_MD5))
            return 16;
        if (type.startsWith(HMAC.HMAC_SHA2_256))
            return 32;
        if (type.startsWith(HMAC.HMAC_SHA2_512))
            return 64;

        throw new IllegalArgumentException("Unknown algorithm " + type);
    }
}