+
−/*
+
− * 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 - 2019 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); }
+
−
+
−	/**
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−	 * Helper method to convert a byte string to a hexadecimal String representation.
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−	 *
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−	 * @param digest The byte array to convert
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−	 * @return The byte array as a hexadecimal string
+
−	 */
+
−	private static String toHex(byte[] digest) {
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−		char[] result = new char[digest.length * 2];
+
−		int pos = 0;
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−		for (byte aDigest : digest) {
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−			result[pos++] = hexChar((aDigest & 0xf0) >> 4);
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−			result[pos++] = hexChar(aDigest & 0x0f);
+
−		}
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−		return new String(result);
+
−	}
+
−
+
−	/**
+
−	 * Digests several byte[] into a String digest, using a specified hash algorithm.
+
−	 *
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−	 * @param algorithm The hash algorithm to use
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−	 * @param toDigests The Strings to digest
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−	 * @return The Strings digest as a hexadecimal string
+
−	 */
+
−	public static String digestStrings(String algorithm, byte[]... toDigests) {
+
−		try {
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−			MessageDigest md = MessageDigest.getInstance(algorithm);
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−			for (byte[] str : toDigests) {
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−				md.update(str);
+
−			}
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−			return toHex(md.digest());
+
−		} catch (NoSuchAlgorithmException e) {
+
−			throw new AssertionError("internal error: " + e.toString());
+
−		}
+
−	}
+
−}