added Whitelist for external configuration overwrites

4 files changed, 90 insertions, 29 deletions

diff --git a/pdf-as-web/src/main/configuration/pdf-as-web.properties b/pdf-as-web/src/main/configuration/pdf-as-web.properties
index 4f6b0661..71bcf386 100644
--- a/pdf-as-web/src/main/configuration/pdf-as-web.properties
+++ b/pdf-as-web/src/main/configuration/pdf-as-web.properties
@@ -10,7 +10,12 @@ bku.local.url=http://127.0.0.1:3495/http-security-layer-request
 bku.mobile.url=https://www.handy-signatur.at/mobile/https-security-layer-request/default.aspx
 
 # Allow full configuration overwrite from external sources
-allow.ext.overwrite=true
+# use with care!
+allow.ext.overwrite=false
+
+# White list entries for properties, that can be overwriten, 
+# by external components
+ext.overwrite.wl.1=^$
 
 ks.enabled=false
 ks.file=test.p12
diff --git a/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/config/WebConfiguration.java b/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/config/WebConfiguration.java
index 5860b740..ca4f2c50 100644
--- a/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/config/WebConfiguration.java
+++ b/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/config/WebConfiguration.java
@@ -50,6 +50,8 @@ public class WebConfiguration implements IConfigurationConstants {
 	public static final String STATISTIC_BACKEND_LIST = "statistic.backends";
 	public static final String ALLOW_EXT_OVERWRITE = "allow.ext.overwrite";
 	
+	public static final String ALLOW_EXT_WHITELIST_VALUE_PRE = "ext.overwrite.wl.";
+	
 	public static final String MOA_SS_ENABLED = "moa.enabled";
 	public static final String SOAP_SIGN_ENABLED = "soap.sign.enabled";
 	public static final String SOAP_VERIFY_ENABLED = "soap.verify.enabled";
@@ -94,11 +96,13 @@ public class WebConfiguration implements IConfigurationConstants {
 			.getLogger(WebConfiguration.class);
 
 	private static List<String> whiteListregEx = new ArrayList<String>();
-
+	private static List<String> overwritewhiteListregEx = new ArrayList<String>();
+	
 	public static void configure(String config) {
 
 		properties.clear();
 		whiteListregEx.clear();
+		overwritewhiteListregEx.clear();
 
 		try {
 			properties.load(new FileInputStream(config));
@@ -123,6 +127,23 @@ public class WebConfiguration implements IConfigurationConstants {
 				}
 			}
 		}
+		
+		if (isAllowExtOverwrite()) {
+			Iterator<Object> keyIt = properties.keySet().iterator();
+			while (keyIt.hasNext()) {
+				Object keyObj = keyIt.next();
+				if (keyObj != null) {
+					String key = keyObj.toString();
+					if (key.startsWith(ALLOW_EXT_WHITELIST_VALUE_PRE)) {
+						String whitelist_expr = properties.getProperty(key);
+						if (whitelist_expr != null) {
+							overwritewhiteListregEx.add(whitelist_expr);
+							logger.debug("Overwrite Whitelist: " + whitelist_expr);
+						}
+					}
+				}
+			}
+		}
 
 		Iterator<Object> keyIt = properties.keySet().iterator();
 		while (keyIt.hasNext()) {
@@ -249,6 +270,26 @@ public class WebConfiguration implements IConfigurationConstants {
 		return false;
 	}
 	
+	public static synchronized boolean isOverwriteAllowed(String key) {
+		if (isAllowExtOverwrite()) {
+
+			Iterator<String> patterns = whiteListregEx.iterator();
+			while (patterns.hasNext()) {
+				String pattern = patterns.next();
+				try {
+					if (key.matches(pattern)) {
+						return true;
+					}
+				} catch (Throwable e) {
+					logger.warn("Error in matching regex: " + pattern, e);
+				}
+			}
+
+			return false;
+		}
+		return false;
+	}
+	
 	public static boolean isMoaEnabled(String keyIdentifier) {
 		String value = properties.getProperty(MOA_LIST + "." + keyIdentifier + ".enabled");
 		if (value != null) {
diff --git a/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/ConfigurationOverwrite.java b/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/ConfigurationOverwrite.java
new file mode 100644
index 00000000..3bf20bf4
--- /dev/null
+++ b/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/ConfigurationOverwrite.java
@@ -0,0 +1,35 @@
+package at.gv.egiz.pdfas.web.helper;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import at.gv.egiz.pdfas.lib.api.Configuration;
+import at.gv.egiz.pdfas.web.config.WebConfiguration;
+
+public class ConfigurationOverwrite {
+
+	private static final Logger logger = LoggerFactory
+			.getLogger(ConfigurationOverwrite.class);
+
+	public static void overwriteConfiguration(Map<String, String> overwrite,
+			Configuration config) {
+		if (WebConfiguration.isAllowExtOverwrite() && overwrite != null && config != null) {
+			Iterator<Entry<String, String>> entryIt = overwrite.entrySet()
+					.iterator();
+			while (entryIt.hasNext()) {
+				Entry<String, String> entry = entryIt.next();
+				if (WebConfiguration.isOverwriteAllowed(entry.getKey())) {
+					config.setValue(entry.getKey(), entry.getValue());
+				} else {
+					logger.warn(
+							"External component tried to overwrite cfg {}. This is not in the whitelist!",
+							entry.getKey());
+				}
+			}
+		}
+	}
+}
diff --git a/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/PdfAsHelper.java b/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/PdfAsHelper.java
index 53cf5783..52eb8468 100644
--- a/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/PdfAsHelper.java
+++ b/pdf-as-web/src/main/java/at/gv/egiz/pdfas/web/helper/PdfAsHelper.java
@@ -36,7 +36,6 @@ import java.security.cert.CertificateException;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import javax.imageio.ImageIO;
 import javax.servlet.RequestDispatcher;
@@ -362,16 +361,9 @@ public class PdfAsHelper {
 
 		Configuration config = pdfAs.getConfiguration();
 
-		if (WebConfiguration.isAllowExtOverwrite()) {
-			Map<String,String> configOverwrite = PdfAsParameterExtractor.getOverwriteMap(request);
-			if(configOverwrite != null) {
-				Iterator<Entry<String, String>> entryIt = configOverwrite.entrySet().iterator();
-				while (entryIt.hasNext()) {
-					Entry<String, String> entry = entryIt.next();
-					config.setValue(entry.getKey(), entry.getValue());
-				}
-			}
-		}
+
+		Map<String,String> configOverwrite = PdfAsParameterExtractor.getOverwriteMap(request);
+		ConfigurationOverwrite.overwriteConfiguration(configOverwrite, config);
 		
 		ByteArrayOutputStream baos = new ByteArrayOutputStream();
 
@@ -502,6 +494,7 @@ public class PdfAsHelper {
 		// set Signature Position
 		signParameter.setSignaturePosition(buildPosString(request, response));
 
+		@SuppressWarnings("unused")
 		SignResult result = pdfAs.sign(signParameter);
 
 		return baos.toByteArray();
@@ -523,15 +516,8 @@ public class PdfAsHelper {
 			PDFASSignParameters params) throws Exception {
 		Configuration config = pdfAs.getConfiguration();
 
-		if (WebConfiguration.isAllowExtOverwrite()) {
-			if (params.getOverrides() != null) {
-				Iterator<Entry<String, String>> entryIt = params.getOverrides()
-						.getMap().entrySet().iterator();
-				while (entryIt.hasNext()) {
-					Entry<String, String> entry = entryIt.next();
-					config.setValue(entry.getKey(), entry.getValue());
-				}
-			}
+		if (WebConfiguration.isAllowExtOverwrite() && params.getOverrides() != null) {
+			ConfigurationOverwrite.overwriteConfiguration(params.getOverrides().getMap(), config);
 		}
 
 		ByteArrayOutputStream baos = new ByteArrayOutputStream();
@@ -702,13 +688,7 @@ public class PdfAsHelper {
 		Configuration config = pdfAs.getConfiguration();
 		session.setAttribute(PDF_CONFIG, config);
 
-		if (WebConfiguration.isAllowExtOverwrite() && overwrite != null) {
-			Iterator<Entry<String, String>> entryIt = overwrite.entrySet().iterator();
-			while (entryIt.hasNext()) {
-				Entry<String, String> entry = entryIt.next();
-				config.setValue(entry.getKey(), entry.getValue());
-			}
-		}
+		ConfigurationOverwrite.overwriteConfiguration(overwrite, config);
 		
 		ByteArrayOutputStream baos = new ByteArrayOutputStream();
 		session.setAttribute(PDF_OUTPUT, baos);