com.groupbyinc.common.apache.commons.codec.digest.B64 Maven / Gradle / Ivy
/*
* 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.util.Random;
/**
* Base64 like method to convert binary bytes into ASCII chars.
*
* TODO: Can Base64 be reused?
*
*
* This class is immutable and thread-safe.
*
*
* @version $Id: B64.java 1435550 2013-01-19 14:09:52Z tn $
* @since 1.7
*/
class B64 {
/**
* Table with characters for Base64 transformation.
*/
static final String B64T = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
/**
* Base64 like conversion of bytes to ASCII chars.
*
* @param b2
* A byte from the result.
* @param b1
* A byte from the result.
* @param b0
* A byte from the result.
* @param outLen
* The number of expected output chars.
* @param buffer
* Where the output chars is appended to.
*/
static void b64from24bit(final byte b2, final byte b1, final byte b0, final int outLen,
final StringBuilder buffer) {
// The bit masking is necessary because the JVM byte type is signed!
int w = ((b2 << 16) & 0x00ffffff) | ((b1 << 8) & 0x00ffff) | (b0 & 0xff);
// It's effectively a "for" loop but kept to resemble the original C code.
int n = outLen;
while (n-- > 0) {
buffer.append(B64T.charAt(w & 0x3f));
w >>= 6;
}
}
/**
* Generates a string of random chars from the B64T set.
*
* @param num
* Number of chars to generate.
*/
static String getRandomSalt(final int num) {
final StringBuilder saltString = new StringBuilder();
for (int i = 1; i <= num; i++) {
saltString.append(B64T.charAt(new Random().nextInt(B64T.length())));
}
return saltString.toString();
}
}