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/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 io.undertow.util;
import io.undertow.UndertowMessages;
import io.undertow.server.HttpServerExchange;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
/**
* Utilities for dealing with URLs
*
* @author Stuart Douglas
*/
public class URLUtils {
private static final char PATH_SEPARATOR = '/';
private static final QueryStringParser QUERY_STRING_PARSER = new QueryStringParser() {
@Override
void handle(HttpServerExchange exchange, String key, String value) {
exchange.addQueryParam(key, value);
}
};
private static final QueryStringParser PATH_PARAM_PARSER = new QueryStringParser() {
@Override
void handle(HttpServerExchange exchange, String key, String value) {
exchange.addPathParam(key, value);
}
};
private URLUtils() {
}
public static void parseQueryString(final String string, final HttpServerExchange exchange, final String charset, final boolean doDecode) {
QUERY_STRING_PARSER.parse(string, exchange, charset, doDecode);
}
public static void parsePathParms(final String string, final HttpServerExchange exchange, final String charset, final boolean doDecode) {
PATH_PARAM_PARSER.parse(string, exchange, charset, doDecode);
}
/**
* Decodes a URL. If the decoding fails for any reason then an IllegalArgumentException will be thrown.
*
* @param s The string to decode
* @param enc The encoding
* @param decodeSlash If slash characters should be decoded
* @param buffer The string builder to use as a buffer.
* @return The decoded URL
*/
public static String decode(String s, String enc, boolean decodeSlash, StringBuilder buffer) {
buffer.setLength(0);
boolean needToChange = false;
int numChars = s.length();
int i = 0;
boolean mightRequireSlashEscape = false;
char c;
byte[] bytes = null;
while (i < numChars) {
c = s.charAt(i);
switch (c) {
case '+':
buffer.append(' ');
i++;
needToChange = true;
break;
case '%':
/*
* Starting with this instance of %, process all
* consecutive substrings of the form %xy. Each
* substring %xy will yield a byte. Convert all
* consecutive bytes obtained this way to whatever
* character(s) they represent in the provided
* encoding.
*/
try {
// (numChars-i)/3 is an upper bound for the number
// of remaining bytes
if (bytes == null) {
bytes = new byte[(numChars - i) / 3];
}
int pos = 0;
while (((i + 2) < numChars) && (c == '%')) {
char p1 = Character.toLowerCase(s.charAt(i + 1));
char p2 = Character.toLowerCase(s.charAt(i + 2));
int v = 0;
if (p1 >= '0' && p1 <= '9') {
v = (p1 - '0') << 4;
} else if (p1 >= 'a' && p1 <= 'f') {
v = (p1 - 'a' + 10) << 4;
} else {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, null);
}
if (p2 >= '0' && p2 <= '9') {
v += (p2 - '0');
} else if (p2 >= 'a' && p2 <= 'f') {
v += (p2 - 'a' + 10);
} else {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, null);
}
if (v < 0) {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, null);
}
if(v == '/' || v== '\\') {
mightRequireSlashEscape = true;
}
bytes[pos++] = (byte) v;
i += 3;
if (i < numChars) {
c = s.charAt(i);
}
}
// A trailing, incomplete byte encoding such as
// "%x" will cause an exception to be thrown
if ((i < numChars) && (c == '%')) {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, null);
}
String decoded = new String(bytes, 0, pos, enc);
if (!decodeSlash && mightRequireSlashEscape) {
//we need to re-encode slash characters
//this is yuck, but a corner case
int decPos = 0;
for (int j = 0; j < decoded.length(); ++j) {
char decChar = decoded.charAt(j);
if (decChar == '/') {
buffer.append(decoded.substring(decPos, j));
buffer.append("%2F");
decPos = j + 1;
} else if (decChar == '\\') {
buffer.append(decoded.substring(decPos, j));
buffer.append("%5C");
decPos = j + 1;
}
}
buffer.append(decoded.substring(decPos));
} else {
buffer.append(decoded);
}
mightRequireSlashEscape = false;
} catch (NumberFormatException e) {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, e);
} catch (UnsupportedEncodingException e) {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, e);
}
needToChange = true;
break;
default:
buffer.append(c);
i++;
if(c > 127 && !needToChange) {
//we have non-ascii data in our URL, which sucks
//its hard to know exactly what to do with this, but we assume that because this data
//has not been properly encoded none of the other data is either
try {
char[] carray = s.toCharArray();
byte[] buf = new byte[carray.length];
for(int l = 0;l < buf.length; ++l) {
buf[l] = (byte) carray[l];
}
return new String(buf, enc);
} catch (UnsupportedEncodingException e) {
throw UndertowMessages.MESSAGES.failedToDecodeURL(s, enc, e);
}
}
break;
}
}
return (needToChange ? buffer.toString() : s);
}
private abstract static class QueryStringParser {
void parse(final String string, final HttpServerExchange exchange, final String charset, final boolean doDecode) {
try {
int stringStart = 0;
String attrName = null;
for (int i = 0; i < string.length(); ++i) {
char c = string.charAt(i);
if (c == '=' && attrName == null) {
attrName = string.substring(stringStart, i);
stringStart = i + 1;
} else if (c == '&') {
if (attrName != null) {
handle(exchange, decode(charset, attrName, doDecode), decode(charset, string.substring(stringStart, i), doDecode));
} else {
handle(exchange, decode(charset, string.substring(stringStart, i), doDecode), "");
}
stringStart = i + 1;
attrName = null;
}
}
if (attrName != null) {
handle(exchange, decode(charset, attrName, doDecode), decode(charset, string.substring(stringStart, string.length()), doDecode));
} else if (string.length() != stringStart) {
handle(exchange, decode(charset, string.substring(stringStart, string.length()), doDecode), "");
}
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
private String decode(String charset, String attrName, final boolean doDecode) throws UnsupportedEncodingException {
if (doDecode) {
return URLDecoder.decode(attrName, charset);
}
return attrName;
}
abstract void handle(final HttpServerExchange exchange, final String key, final String value);
}
/**
* Adds a '/' prefix to the beginning of a path if one isn't present
* and removes trailing slashes if any are present.
*
* @param path the path to normalize
* @return a normalized (with respect to slashes) result
*/
public static String normalizeSlashes(final String path) {
// prepare
final StringBuilder builder = new StringBuilder(path);
boolean modified = false;
// remove all trailing '/'s except the first one
while (builder.length() > 0 && builder.length() != 1 && PATH_SEPARATOR == builder.charAt(builder.length() - 1)) {
builder.deleteCharAt(builder.length() - 1);
modified = true;
}
// add a slash at the beginning if one isn't present
if (builder.length() == 0 || PATH_SEPARATOR != builder.charAt(0)) {
builder.insert(0, PATH_SEPARATOR);
modified = true;
}
// only create string when it was modified
if (modified) {
return builder.toString();
}
return path;
}
}
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