SSIMediator.java
/*
* 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.catalina.ssi;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Collection;
import java.util.Date;
import java.util.HashSet;
import java.util.Locale;
import java.util.Set;
import java.util.TimeZone;
import java.util.regex.Matcher;
import org.apache.catalina.util.Strftime;
import org.apache.catalina.util.URLEncoder;
import org.apache.tomcat.util.res.StringManager;
import org.apache.tomcat.util.security.Escape;
/**
* Allows the different SSICommand implementations to share data/talk to each other
*
* @author Bip Thelin
* @author Amy Roh
* @author Paul Speed
* @author Dan Sandberg
* @author David Becker
*/
public class SSIMediator {
private static final StringManager sm = StringManager.getManager(SSIMediator.class);
protected static final String ENCODING_NONE = "none";
protected static final String ENCODING_ENTITY = "entity";
protected static final String ENCODING_URL = "url";
protected static final String DEFAULT_CONFIG_ERR_MSG = "[an error occurred while processing this directive]";
protected static final String DEFAULT_CONFIG_TIME_FMT = "%A, %d-%b-%Y %T %Z";
protected static final String DEFAULT_CONFIG_SIZE_FMT = "abbrev";
protected String configErrMsg = DEFAULT_CONFIG_ERR_MSG;
protected String configTimeFmt = DEFAULT_CONFIG_TIME_FMT;
protected String configSizeFmt = DEFAULT_CONFIG_SIZE_FMT;
protected final String className = getClass().getName();
protected final SSIExternalResolver ssiExternalResolver;
protected final long lastModifiedDate;
protected Strftime strftime;
protected final SSIConditionalState conditionalState = new SSIConditionalState();
protected int lastMatchCount = 0;
public SSIMediator(SSIExternalResolver ssiExternalResolver, long lastModifiedDate) {
this.ssiExternalResolver = ssiExternalResolver;
this.lastModifiedDate = lastModifiedDate;
setConfigTimeFmt(DEFAULT_CONFIG_TIME_FMT, true);
}
public void setConfigErrMsg(String configErrMsg) {
this.configErrMsg = configErrMsg;
}
public void setConfigTimeFmt(String configTimeFmt) {
setConfigTimeFmt(configTimeFmt, false);
}
public void setConfigTimeFmt(String configTimeFmt, boolean fromConstructor) {
this.configTimeFmt = configTimeFmt;
this.strftime = new Strftime(configTimeFmt, Locale.US);
/*
* Variables like DATE_LOCAL, DATE_GMT, and LAST_MODIFIED need to be updated when the timefmt changes. This is
* what Apache SSI does.
*/
setDateVariables(fromConstructor);
}
public void setConfigSizeFmt(String configSizeFmt) {
this.configSizeFmt = configSizeFmt;
}
public String getConfigErrMsg() {
return configErrMsg;
}
public String getConfigTimeFmt() {
return configTimeFmt;
}
public String getConfigSizeFmt() {
return configSizeFmt;
}
public SSIConditionalState getConditionalState() {
return conditionalState;
}
public Collection<String> getVariableNames() {
Set<String> variableNames = new HashSet<>();
// These built-in variables are supplied by the mediator (if not over-written by the user) and always exist
variableNames.add("DATE_GMT");
variableNames.add("DATE_LOCAL");
variableNames.add("LAST_MODIFIED");
ssiExternalResolver.addVariableNames(variableNames);
// Remove any variables that are reserved by this class
variableNames.removeIf(this::isNameReserved);
return variableNames;
}
public long getFileSize(String path, boolean virtual) throws IOException {
return ssiExternalResolver.getFileSize(path, virtual);
}
public long getFileLastModified(String path, boolean virtual) throws IOException {
return ssiExternalResolver.getFileLastModified(path, virtual);
}
public String getFileText(String path, boolean virtual) throws IOException {
return ssiExternalResolver.getFileText(path, virtual);
}
protected boolean isNameReserved(String name) {
return name.startsWith(className + ".");
}
public String getVariableValue(String variableName) {
return getVariableValue(variableName, ENCODING_NONE);
}
public void setVariableValue(String variableName, String variableValue) {
if (!isNameReserved(variableName)) {
ssiExternalResolver.setVariableValue(variableName, variableValue);
}
}
public String getVariableValue(String variableName, String encoding) {
String lowerCaseVariableName = variableName.toLowerCase(Locale.ENGLISH);
String variableValue = null;
if (!isNameReserved(lowerCaseVariableName)) {
// Try getting it externally first, if it fails, try getting the 'built-in' value
variableValue = ssiExternalResolver.getVariableValue(variableName);
if (variableValue == null) {
variableName = variableName.toUpperCase(Locale.ENGLISH);
variableValue = ssiExternalResolver.getVariableValue(className + "." + variableName);
}
if (variableValue != null) {
variableValue = encode(variableValue, encoding);
}
}
return variableValue;
}
/**
* Applies variable substitution to the specified String and returns the new resolved string.
*
* @param val The value which should be checked
*
* @return the value after variable substitution
*/
public String substituteVariables(String val) {
// If it has no references or HTML entities then no work need to be done
if (val.indexOf('$') < 0 && val.indexOf('&') < 0) {
return val;
}
// HTML decoding
val = val.replace("<", "<");
val = val.replace(">", ">");
val = val.replace(""", "\"");
val = val.replace("&", "&");
StringBuilder sb = new StringBuilder(val);
int charStart = sb.indexOf("&#");
while (charStart > -1) {
int charEnd = sb.indexOf(";", charStart);
if (charEnd > -1) {
char c = (char) Integer.parseInt(sb.substring(charStart + 2, charEnd));
sb.delete(charStart, charEnd + 1);
sb.insert(charStart, c);
charStart = sb.indexOf("&#");
} else {
break;
}
}
for (int i = 0; i < sb.length();) {
// Find the next $
for (; i < sb.length(); i++) {
if (sb.charAt(i) == '$') {
i++;
break;
}
}
if (i == sb.length()) {
break;
}
// Check to see if the $ is escaped
if (i > 1 && sb.charAt(i - 2) == '\\') {
sb.deleteCharAt(i - 2);
i--;
continue;
}
int nameStart = i;
int start = i - 1;
int end = -1;
int nameEnd = -1;
char endChar = ' ';
// Check for {} wrapped var
if (sb.charAt(i) == '{') {
nameStart++;
endChar = '}';
}
// Find the end of the var reference
for (; i < sb.length(); i++) {
if (sb.charAt(i) == endChar) {
break;
}
}
end = i;
nameEnd = end;
if (endChar == '}') {
end++;
}
// We should now have enough to extract the var name
String varName = sb.substring(nameStart, nameEnd);
String value = getVariableValue(varName);
if (value == null) {
value = "";
}
// Replace the var name with its value
sb.replace(start, end, value);
// Start searching for the next $ after the value that was just substituted.
i = start + value.length();
}
return sb.toString();
}
protected String formatDate(Date date, TimeZone timeZone) {
String retVal;
if (timeZone != null) {
// we temporarily change strftime. Since SSIMediator is inherently single-threaded, this isn't a problem
TimeZone oldTimeZone = strftime.getTimeZone();
strftime.setTimeZone(timeZone);
retVal = strftime.format(date);
strftime.setTimeZone(oldTimeZone);
} else {
retVal = strftime.format(date);
}
return retVal;
}
protected String encode(String value, String encoding) {
String retVal = null;
if (encoding.equalsIgnoreCase(ENCODING_URL)) {
retVal = URLEncoder.DEFAULT.encode(value, StandardCharsets.UTF_8);
} else if (encoding.equalsIgnoreCase(ENCODING_NONE)) {
retVal = value;
} else if (encoding.equalsIgnoreCase(ENCODING_ENTITY)) {
retVal = Escape.htmlElementContent(value);
} else {
// This shouldn't be possible
throw new IllegalArgumentException(sm.getString("ssiMediator.unknownEncoding", encoding));
}
return retVal;
}
public void log(String message) {
ssiExternalResolver.log(message, null);
}
public void log(String message, Throwable throwable) {
ssiExternalResolver.log(message, throwable);
}
protected void setDateVariables(boolean fromConstructor) {
boolean alreadySet = ssiExternalResolver.getVariableValue(className + ".alreadyset") != null;
// skip this if we are being called from the constructor, and this has already been set
if (!(fromConstructor && alreadySet)) {
ssiExternalResolver.setVariableValue(className + ".alreadyset", "true");
Date date = new Date();
TimeZone timeZone = TimeZone.getTimeZone("GMT");
String retVal = formatDate(date, timeZone);
/*
* If we are setting on of the date variables, we want to remove them from the user defined list of
* variables, because this is what Apache does.
*/
setVariableValue("DATE_GMT", null);
ssiExternalResolver.setVariableValue(className + ".DATE_GMT", retVal);
retVal = formatDate(date, null);
setVariableValue("DATE_LOCAL", null);
ssiExternalResolver.setVariableValue(className + ".DATE_LOCAL", retVal);
retVal = formatDate(new Date(lastModifiedDate), null);
setVariableValue("LAST_MODIFIED", null);
ssiExternalResolver.setVariableValue(className + ".LAST_MODIFIED", retVal);
}
}
protected void clearMatchGroups() {
for (int i = 1; i <= lastMatchCount; i++) {
setVariableValue(Integer.toString(i), "");
}
lastMatchCount = 0;
}
protected void populateMatchGroups(Matcher matcher) {
lastMatchCount = matcher.groupCount();
// $0 is not used
if (lastMatchCount == 0) {
return;
}
for (int i = 1; i <= lastMatchCount; i++) {
setVariableValue(Integer.toString(i), matcher.group(i));
}
}
}