com.google.gerrit.entities.KeyUtil Maven / Gradle / Ivy
// Copyright (C) 2019 The Android Open Source Project
//
// Licensed 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 com.google.gerrit.entities;
import static java.nio.charset.StandardCharsets.UTF_8;
import java.util.Arrays;
public class KeyUtil {
private static final char[] hexc = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
private static final char safe[];
private static final byte hexb[];
static {
safe = new char[256];
safe['-'] = '-';
safe['_'] = '_';
safe['.'] = '.';
safe['!'] = '!';
safe['~'] = '~';
safe['*'] = '*';
safe['\''] = '\'';
safe['('] = '(';
safe[')'] = ')';
safe['/'] = '/';
safe[' '] = '+';
for (char c = '0'; c <= '9'; c++) safe[c] = c;
for (char c = 'A'; c <= 'Z'; c++) safe[c] = c;
for (char c = 'a'; c <= 'z'; c++) safe[c] = c;
hexb = new byte['f' + 1];
Arrays.fill(hexb, (byte) -1);
for (char i = '0'; i <= '9'; i++) hexb[i] = (byte) (i - '0');
for (char i = 'A'; i <= 'F'; i++) hexb[i] = (byte) ((i - 'A') + 10);
for (char i = 'a'; i <= 'f'; i++) hexb[i] = (byte) ((i - 'a') + 10);
}
public static String encode(final String key) {
final byte[] b = key.getBytes(UTF_8);
final StringBuilder r = new StringBuilder(b.length);
for (int i = 0; i < b.length; i++) {
final int c = b[i] & 0xff;
final char s = safe[c];
if (s == 0) {
r.append('%');
r.append(hexc[c >> 4]);
r.append(hexc[c & 15]);
} else {
r.append(s);
}
}
return r.toString();
}
public static String decode(String key) {
// URLs use percentage encoding which replaces unsafe ASCII characters with a '%' followed by
// two hexadecimal digits. If there is '%' that is not followed by two hexadecimal digits
// the code below fails with an IllegalArgumentException. To prevent this replace any '%'
// that is not followed by two hexadecimal digits by "%25", which is the URL encoding for '%'.
key = key.replaceAll("%(?![0-9a-fA-F]{2})", "%25");
if (key.indexOf('%') < 0) {
return key.replace('+', ' ');
}
final byte[] b = new byte[key.length()];
int bPtr = 0;
try {
for (int i = 0; i < key.length(); ) {
final char c = key.charAt(i);
if (c == '%' && i + 2 < key.length()) {
final int v = (hexb[key.charAt(i + 1)] << 4) | hexb[key.charAt(i + 2)];
if (v < 0) {
throw new IllegalArgumentException(key.substring(i, i + 3));
}
b[bPtr++] = (byte) v;
i += 3;
} else if (c == '+') {
b[bPtr++] = ' ';
i++;
} else {
b[bPtr++] = (byte) c;
i++;
}
}
} catch (ArrayIndexOutOfBoundsException err) {
throw new IllegalArgumentException("Bad encoding" + key, err);
}
return new String(b, 0, bPtr, UTF_8);
}
}