+
−/*
+
− * This Source Code Form is subject to the terms of the Mozilla Public
+
− * License, v. 2.0.  If a copy of the MPL was not distributed with this
+
− * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
− *
+
− * Copyright 1997 - July 2008 CWI, August 2008 - 2017 MonetDB B.V.
+
− */
+
−
+
−package nl.cwi.monetdb.mcl.connection.helpers;
+
−
+
−import java.security.MessageDigest;
+
−import java.security.NoSuchAlgorithmException;
+
−
+
−/**
+
− * A helper class to process Hash digests during the authentication process.
+
− *
+
− * @author Fabian Groffen, Pedro Ferreira
+
− */
+
−public final class ChannelSecurity {
+
−
+
−    private static char hexChar(int n) { return (n > 9) ? (char) ('a' + (n - 10)) : (char) ('0' + n); }
+
−
+
−    /**
+
−     * Helper method to convert a byte string to a hexadecimal String representation.
+
−     *
+
−     * @param digest The byte array to convert
+
−     * @return The byte array as a hexadecimal string
+
−     */
+
−    private static String toHex(byte[] digest) {
+
−        char[] result = new char[digest.length * 2];
+
−        int pos = 0;
+
−        for (byte aDigest : digest) {
+
−            result[pos++] = hexChar((aDigest & 0xf0) >> 4);
+
−            result[pos++] = hexChar(aDigest & 0x0f);
+
−        }
+
−        return new String(result);
+
−    }
+
−
+
−    /**
+
−     * Digests several byte[] into a String digest, using a specified hash algorithm.
+
−     *
+
−     * @param algorithm The hash algorithm to use
+
−     * @param toDigests The Strings to digest
+
−     * @return The Strings digest as a hexadecimal string
+
−     */
+
−    public static String digestStrings(String algorithm, byte[]... toDigests) {
+
−        try {
+
−            MessageDigest md = MessageDigest.getInstance(algorithm);
+
−            for (byte[] str : toDigests) {
+
−                md.update(str);
+
−            }
+
−            return toHex(md.digest());
+
−        } catch (NoSuchAlgorithmException e) {
+
−            throw new AssertionError("internal error: " + e.toString());
+
−        }
+
−    }
+
−}