base.text.Password Maven / Gradle / Ivy

/*
 This is free and unencumbered software released into the public domain.

 Anyone is free to copy, modify, publish, use, compile, sell, or
 distribute this software, either in source code form or as a compiled
 binary, for any purpose, commercial or non-commercial, and by any
 means.

 In jurisdictions that recognize copyright laws, the author or authors
 of this software dedicate any and all copyright interest in the
 software to the public domain. We make this dedication for the benefit
 of the public at large and to the detriment of our heirs and
 successors. We intend this dedication to be an overt act of
 relinquishment in perpetuity of all present and future rights to this
 software under copyright law.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 OTHER DEALINGS IN THE SOFTWARE.
 */
package base.text;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Utility functions related to string management.
 */
public class Password {

	/**
	 * Return a salted SHA-256 hashed version of a password, in the
	 * format salt:passwordhash.
	 *
	 * @param password The unhashed version of a users password.
	 * @return The salted and hashed version of a users password.
	 * @throws NoSuchAlgorithmException
	 * @throws UnsupportedEncodingException
	 * @see Password#verifyPassword(String, String)
	 */
	public static String encode(String password) throws NoSuchAlgorithmException, UnsupportedEncodingException {
		String salt = StringHelper.randomString(16);
		MessageDigest md = MessageDigest.getInstance("SHA-256");
		md.update((salt + password).getBytes("UTF-8"));
		return salt + ":" + Base64Encode.encode(md.digest());
	}

	/**
	 * Verify a password matches its password hash. A colon in the password indicates
	 * the password hash has a salt. Null passwords or password hashes never match.
	 *
	 * @param passwordHash The salted and hashed password.
	 * @param password A password to compare to the salted and hashed password.
	 * @return True if the password matches the password hash.
	 * @throws NoSuchAlgorithmException
	 * @throws UnsupportedEncodingException
	 * @see Password#encode(String)
	 */
	public static boolean verifyPassword(String passwordHash, String password) throws NoSuchAlgorithmException, UnsupportedEncodingException {
		if(passwordHash == null || password == null) {
			return false;
		}

		if(passwordHash.contains(":")) {
			String[] part = passwordHash.split(":");
			MessageDigest md = MessageDigest.getInstance("SHA-256");
			md.update((part[0] + password).getBytes("UTF-8"));
			return Base64Encode.encode(md.digest()).equals(part[1]);
		} else {
			return StringHelper.shaHash(password).equals(passwordHash);
		}
	}

}