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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.codec.digest;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.util.concurrent.ThreadLocalRandom;
/**
* GNU libc crypt(3) compatible hash method.
*
* See {@link #crypt(String, String)} for further details.
*
* This class is immutable and thread-safe.
*
* @since 1.7
*/
public class Crypt {
/**
* Encrypts a password in a crypt(3) compatible way.
*
* A random salt and the default algorithm (currently SHA-512) are used. See {@link #crypt(String, String)} for
* details.
*
*
* A salt is generated for you using {@link ThreadLocalRandom}; for more secure salts consider using
* {@link SecureRandom} to generate your own salts and calling {@link #crypt(byte[], String)}.
*
*
* @param keyBytes
* plaintext password
* @return hash value
* @throws IllegalArgumentException
* when a {@link java.security.NoSuchAlgorithmException} is caught.
*/
public static String crypt(final byte[] keyBytes) {
return crypt(keyBytes, null);
}
/**
* Encrypts a password in a crypt(3) compatible way.
*
* If no salt is provided, a random salt and the default algorithm (currently SHA-512) will be used. See
* {@link #crypt(String, String)} for details.
*
* @param keyBytes
* plaintext password
* @param salt
* real salt value without prefix or "rounds=". The salt may be null,
* in which case a salt is generated for you using {@link ThreadLocalRandom};
* for more secure salts consider using {@link SecureRandom} to
* generate your own salts.
* @return hash value
* @throws IllegalArgumentException
* if the salt does not match the allowed pattern
* @throws IllegalArgumentException
* when a {@link java.security.NoSuchAlgorithmException} is caught.
*/
public static String crypt(final byte[] keyBytes, final String salt) {
if (salt == null) {
return Sha2Crypt.sha512Crypt(keyBytes);
} else if (salt.startsWith(Sha2Crypt.SHA512_PREFIX)) {
return Sha2Crypt.sha512Crypt(keyBytes, salt);
} else if (salt.startsWith(Sha2Crypt.SHA256_PREFIX)) {
return Sha2Crypt.sha256Crypt(keyBytes, salt);
} else if (salt.startsWith(Md5Crypt.MD5_PREFIX)) {
return Md5Crypt.md5Crypt(keyBytes, salt);
} else {
return UnixCrypt.crypt(keyBytes, salt);
}
}
/**
* Calculates the digest using the strongest crypt(3) algorithm.
*
* A random salt and the default algorithm (currently SHA-512) are used.
*
*
* A salt is generated for you using {@link ThreadLocalRandom}; for more secure salts consider using
* {@link SecureRandom} to generate your own salts and calling {@link #crypt(String, String)}.
*
*
* @see #crypt(String, String)
* @param key
* plaintext password
* @return hash value
* @throws IllegalArgumentException
* when a {@link java.security.NoSuchAlgorithmException} is caught.
*/
public static String crypt(final String key) {
return crypt(key, null);
}
/**
* Encrypts a password in a crypt(3) compatible way.
*
* The exact algorithm depends on the format of the salt string:
*
* - SHA-512 salts start with {@code $6$} and are up to 16 chars long.
*
- SHA-256 salts start with {@code $5$} and are up to 16 chars long
*
- MD5 salts start with {@code $1$} and are up to 8 chars long
*
- DES, the traditional UnixCrypt algorithm is used with only 2 chars
*
- Only the first 8 chars of the passwords are used in the DES algorithm!
*
* The magic strings {@code "$apr1$"} and {@code "$2a$"} are not recognized by this method as its output should be
* identical with that of the libc implementation.
*
* The rest of the salt string is drawn from the set {@code [a-zA-Z0-9./]} and is cut at the maximum length of if a
* {@code "$"} sign is encountered. It is therefore valid to enter a complete hash value as salt to e.g. verify a
* password with:
*
*
* storedPwd.equals(crypt(enteredPwd, storedPwd))
*
*
* The resulting string starts with the marker string ({@code $n$}), where n is the same as the input salt.
* The salt is then appended, followed by a {@code "$"} sign.
* This is followed by the actual hash value.
* For DES the string only contains the salt and actual hash.
* The total length is dependent on the algorithm used:
*
* - SHA-512: 106 chars
*
- SHA-256: 63 chars
*
- MD5: 34 chars
*
- DES: 13 chars
*
*
* Example:
*
*
* crypt("secret", "$1$xxxx") => "$1$xxxx$aMkevjfEIpa35Bh3G4bAc."
* crypt("secret", "xx") => "xxWAum7tHdIUw"
*
*
* This method comes in a variation that accepts a byte[] array to support input strings that are not encoded in
* UTF-8 but e.g. in ISO-8859-1 where equal characters result in different byte values.
*
* @see "The man page of the libc crypt (3) function."
* @param key
* plaintext password as entered by the used
* @param salt
* real salt value without prefix or "rounds=". The salt may be null, in which case a
* salt is generated for you using {@link ThreadLocalRandom}; for more secure salts
* consider using {@link SecureRandom} to generate your own salts.
* @return hash value, i.e. encrypted password including the salt string
* @throws IllegalArgumentException
* if the salt does not match the allowed pattern
* @throws IllegalArgumentException
* when a {@link java.security.NoSuchAlgorithmException} is caught. *
*/
public static String crypt(final String key, final String salt) {
return crypt(key.getBytes(StandardCharsets.UTF_8), salt);
}
}