/**
* OLAT - Online Learning and Training<br>
* http://www.olat.org
* <p>
* Licensed under the Apache License, Version 2.0 (the "License"); <br>
* you may not use this file except in compliance with the License.<br>
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing,<br>
* software distributed under the License is distributed on an "AS IS" BASIS, <br>
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
* See the License for the specific language governing permissions and <br>
* limitations under the License.
* <p>
* Copyright (c) since 2004 at Multimedia- & E-Learning Services (MELS),<br>
* University of Zurich, Switzerland.
* <hr>
* <a href="http://www.openolat.org">
* OpenOLAT - Online Learning and Training</a><br>
* This file has been modified by the OpenOLAT community. Changes are licensed
* under the Apache 2.0 license as the original file.
*/
package org.olat.core.commons.services.webdav.servlets;
import java.io.UnsupportedEncodingException;
import java.text.Normalizer;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.TimeZone;
import javax.servlet.http.Cookie;
/**
* General purpose request parsing and encoding utility methods.
*
* @author Craig R. McClanahan
* @author Tim Tye
*/
public final class RequestUtil {
/**
* The DateFormat to use for generating readable dates in cookies.
*/
private static SimpleDateFormat format =
new SimpleDateFormat(" EEEE, dd-MMM-yy kk:mm:ss zz");
static {
format.setTimeZone(TimeZone.getTimeZone("GMT"));
}
/**
* Encode a cookie as per RFC 2109. The resulting string can be used
* as the value for a <code>Set-Cookie</code> header.
*
* @param cookie The cookie to encode.
* @return A string following RFC 2109.
*/
public static String encodeCookie(Cookie cookie) {
StringBuilder buf = new StringBuilder( cookie.getName() );
buf.append("=");
buf.append(cookie.getValue());
if (cookie.getComment() != null) {
buf.append("; Comment=\"");
buf.append(cookie.getComment());
buf.append("\"");
}
if (cookie.getDomain() != null) {
buf.append("; Domain=\"");
buf.append(cookie.getDomain());
buf.append("\"");
}
if (cookie.getMaxAge() >= 0) {
buf.append("; Max-Age=\"");
buf.append(cookie.getMaxAge());
buf.append("\"");
}
if (cookie.getPath() != null) {
buf.append("; Path=\"");
buf.append(cookie.getPath());
buf.append("\"");
}
if (cookie.getSecure()) {
buf.append("; Secure");
}
if (cookie.getVersion() > 0) {
buf.append("; Version=\"");
buf.append(cookie.getVersion());
buf.append("\"");
}
return (buf.toString());
}
/**
* Filter the specified message string for characters that are sensitive
* in HTML. This avoids potential attacks caused by including JavaScript
* codes in the request URL that is often reported in error messages.
*
* @param message The message string to be filtered
*/
public static String filter(String message) {
if (message == null)
return (null);
char content[] = new char[message.length()];
message.getChars(0, message.length(), content, 0);
StringBuilder result = new StringBuilder(content.length + 50);
for (int i = 0; i < content.length; i++) {
switch (content[i]) {
case '<':
result.append("<");
break;
case '>':
result.append(">");
break;
case '&':
result.append("&");
break;
case '"':
result.append(""");
break;
default:
result.append(content[i]);
}
}
return (result.toString());
}
/**
* Normalize a relative URI path that may have relative values ("/./",
* "/../", and so on ) it it. <strong>WARNING</strong> - This method is
* useful only for normalizing application-generated paths. It does not
* try to perform security checks for malicious input.
*
* @param path Relative path to be normalized
*/
public static String normalize(String path) {
if (path == null)
return null;
// Create a place for the normalized path
String normalized = path;
if (normalized.equals("/."))
return "/";
// Add a leading "/" if necessary
if (!normalized.startsWith("/"))
normalized = "/" + normalized;
// Resolve occurrences of "//" in the normalized path
while (true) {
int index = normalized.indexOf("//");
if (index < 0)
break;
normalized = normalized.substring(0, index) +
normalized.substring(index + 1);
}
// Resolve occurrences of "/./" in the normalized path
while (true) {
int index = normalized.indexOf("/./");
if (index < 0)
break;
normalized = normalized.substring(0, index) +
normalized.substring(index + 2);
}
// Resolve occurrences of "/../" in the normalized path
while (true) {
int index = normalized.indexOf("/../");
if (index < 0)
break;
if (index == 0)
return (null); // Trying to go outside our context
int index2 = normalized.lastIndexOf('/', index - 1);
normalized = normalized.substring(0, index2) +
normalized.substring(index + 3);
}
// Return the normalized path that we have completed
return (normalized);
}
/**
* Parse the character encoding from the specified content type header.
* If the content type is null, or there is no explicit character encoding,
* <code>null</code> is returned.
*
* @param contentType a content type header
*/
public static String parseCharacterEncoding(String contentType) {
if (contentType == null)
return (null);
int start = contentType.indexOf("charset=");
if (start < 0)
return (null);
String encoding = contentType.substring(start + 8);
int end = encoding.indexOf(';');
if (end >= 0)
encoding = encoding.substring(0, end);
encoding = encoding.trim();
if ((encoding.length() > 2) && (encoding.startsWith("\""))
&& (encoding.endsWith("\"")))
encoding = encoding.substring(1, encoding.length() - 1);
return (encoding.trim());
}
/**
* Parse a cookie header into an array of cookies according to RFC 2109.
*
* @param header Value of an HTTP "Cookie" header
*/
public static Cookie[] parseCookieHeader(String header) {
if ((header == null) || (header.length() < 1))
return (new Cookie[0]);
List<Cookie> cookies = new ArrayList<Cookie>();
while (header.length() > 0) {
int semicolon = header.indexOf(';');
if (semicolon < 0)
semicolon = header.length();
if (semicolon == 0)
break;
String token = header.substring(0, semicolon);
if (semicolon < header.length())
header = header.substring(semicolon + 1);
else
header = "";
try {
int equals = token.indexOf('=');
if (equals > 0) {
String name = token.substring(0, equals).trim();
String value = token.substring(equals+1).trim();
cookies.add(new Cookie(name, value));
}
} catch (Throwable e) {
}
}
return cookies.toArray(new Cookie[cookies.size()]);
}
/**
* Append request parameters from the specified String to the specified
* Map. It is presumed that the specified Map is not accessed from any
* other thread, so no synchronization is performed.
* <p>
* <strong>IMPLEMENTATION NOTE</strong>: URL decoding is performed
* individually on the parsed name and value elements, rather than on
* the entire query string ahead of time, to properly deal with the case
* where the name or value includes an encoded "=" or "&" character
* that would otherwise be interpreted as a delimiter.
*
* @param map Map that accumulates the resulting parameters
* @param data Input string containing request parameters
* @param urlParameters true if we're parsing parameters on the URL
*
* @exception IllegalArgumentException if the data is malformed
*/
public static void parseParameters(Map<String,String[]> map, String data, String encoding)
throws UnsupportedEncodingException {
if ((data != null) && (data.length() > 0)) {
parseParameters(map, data.getBytes(encoding), encoding);
}
}
/**
* Decode and return the specified URL-encoded String.
* When the byte array is converted to a string, the system default
* character encoding is used... This may be different than some other
* servers.
*
* @param str The url-encoded string
*
* @exception IllegalArgumentException if a '%' character is not followed
* by a valid 2-digit hexadecimal number
*/
public static String URLDecode(String str) {
return URLDecode(str, null);
}
/**
* Decode and return the specified URL-encoded String.
*
* @param str The url-encoded string
* @param enc The encoding to use; if null, the default encoding is used
* @exception IllegalArgumentException if a '%' character is not followed
* by a valid 2-digit hexadecimal number
*/
public static String URLDecode(String str, String enc) {
return (str == null) ? null : URLDecode(str.getBytes(), enc);
}
/**
* Decode and return the specified URL-encoded byte array.
*
* @param bytes The url-encoded byte array
* @exception IllegalArgumentException if a '%' character is not followed
* by a valid 2-digit hexadecimal number
*/
public static String URLDecode(byte[] bytes) {
return URLDecode(bytes, null);
}
/**
* Decode and return the specified URL-encoded byte array.
*
* @param bytes The url-encoded byte array
* @param enc The encoding to use; if null, the default encoding is used
* @exception IllegalArgumentException if a '%' character is not followed
* by a valid 2-digit hexadecimal number
*/
public static String URLDecode(byte[] bytes, String enc) {
if (bytes == null)
return (null);
int len = bytes.length;
int ix = 0;
int ox = 0;
while (ix < len) {
byte b = bytes[ix++]; // Get byte to test
if (b == '+') {
b = (byte)' ';
} else if (b == '%') {
b = (byte) ((convertHexDigit(bytes[ix++]) << 4)
+ convertHexDigit(bytes[ix++]));
}
bytes[ox++] = b;
}
if (enc != null) {
try {
return new String(bytes, 0, ox, enc);
} catch (Exception e) {} // will return String with default encodeing
}
return new String(bytes, 0, ox);
}
/**
* Convert a byte character value to hexidecimal digit value.
*
* @param b the character value byte
*/
private static byte convertHexDigit( byte b ) {
if ((b >= '0') && (b <= '9')) return (byte)(b - '0');
if ((b >= 'a') && (b <= 'f')) return (byte)(b - 'a' + 10);
if ((b >= 'A') && (b <= 'F')) return (byte)(b - 'A' + 10);
return 0;
}
/**
* Put name value pair in map.
*
* @param b the character value byte
*
* Put name and value pair in map. When name already exist, add value
* to array of values.
*/
private static void putMapEntry( Map<String,String[]> map, String name, String value) {
String[] newValues = null;
String[] oldValues = map.get(name);
if (oldValues == null) {
newValues = new String[1];
newValues[0] = value;
} else {
newValues = new String[oldValues.length + 1];
System.arraycopy(oldValues, 0, newValues, 0, oldValues.length);
newValues[oldValues.length] = value;
}
map.put(name, newValues);
}
/**
* Append request parameters from the specified String to the specified
* Map. It is presumed that the specified Map is not accessed from any
* other thread, so no synchronization is performed.
* <p>
* <strong>IMPLEMENTATION NOTE</strong>: URL decoding is performed
* individually on the parsed name and value elements, rather than on
* the entire query string ahead of time, to properly deal with the case
* where the name or value includes an encoded "=" or "&" character
* that would otherwise be interpreted as a delimiter.
*
* NOTE: byte array data is modified by this method. Caller beware.
*
* @param map Map that accumulates the resulting parameters
* @param data Input string containing request parameters
* @param encoding Encoding to use for converting hex
*
* @exception UnsupportedEncodingException if the data is malformed
*/
public static void parseParameters(Map<String,String[]> map, byte[] data, String encoding)
throws UnsupportedEncodingException {
if (data != null && data.length > 0) {
int ix = 0;
int ox = 0;
String key = null;
String value = null;
while (ix < data.length) {
byte c = data[ix++];
switch ((char) c) {
case '&':
value = new String(data, 0, ox, encoding);
if (key != null) {
putMapEntry(map, key, value);
key = null;
}
ox = 0;
break;
case '=':
key = new String(data, 0, ox, encoding);
ox = 0;
break;
case '+':
data[ox++] = (byte)' ';
break;
case '%':
data[ox++] = (byte)((convertHexDigit(data[ix++]) << 4)
+ convertHexDigit(data[ix++]));
break;
default:
data[ox++] = c;
}
}
//The last value does not end in '&'. So save it now.
if (key != null) {
value = new String(data, 0, ox, encoding);
putMapEntry(map, key, value);
}
}
}
/**
* This method remove some special characters as space, >, <,
* slash .. but preserve Umlauts. () are acceptable
* @return
*/
public static String normalizeFilename(String filename) {
StringBuilder sb = new StringBuilder(filename.length());
char[] chars = filename.toCharArray();
int numOfChars = chars.length;
for(int i=0; i<numOfChars; i++) {
char ch = chars[i];
switch(ch) {
case '/': sb.append('_'); break;
case '\\': sb.append('_'); break;
case '?': sb.append('_'); break;
case '<': sb.append('_'); break;
case '>': sb.append('_'); break;
case '%': sb.append('_'); break;
case '"': sb.append('_'); break;
case '\'': sb.append('_'); break;
case ':': sb.append('_'); break;
case '*': sb.append('_'); break;
case '&': sb.append('_'); break;
case '.': sb.append('_'); break;
default: sb.append(ch);
}
}
return Normalizer.normalize(sb, Normalizer.Form.NFC);
}
}