nifi-commons/nifi-sensitive-property-provider/src/main/java/org/apache/nifi/properties/ApplicationPropertiesProtector.java - nifi - Git at Google

 /*
  * 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.nifi.properties;

 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Properties;
 import java.util.Set;
 import java.util.stream.Collectors;

 import static java.util.Arrays.asList;

 /**
  * Class performing unprotection activities before returning a clean
  * implementation of {@link ApplicationProperties}.
  * This encapsulates the sensitive property access logic from external consumers
  * of {@code ApplicationProperties}.
  *
  * @param <T> The type of protected application properties
  * @param <U> The type of standard application properties that backs the protected application properties
  */
 public class ApplicationPropertiesProtector<T extends ProtectedProperties<U>, U extends ApplicationProperties>
         implements SensitivePropertyProtector<T, U> {
     public static final String PROTECTED_KEY_SUFFIX = ".protected";

     private static final Logger logger = LoggerFactory.getLogger(ApplicationPropertiesProtector.class);

     private T protectedProperties;

     private Map<String, SensitivePropertyProvider> localProviderCache = new HashMap<>();

     /**
      * Creates an instance containing the provided {@link ProtectedProperties}.
      *
      * @param protectedProperties the ProtectedProperties to contain
      */
     public ApplicationPropertiesProtector(final T protectedProperties) {
         this.protectedProperties = protectedProperties;
         logger.debug("Loaded {} properties (including {} protection schemes) into {}", getPropertyKeysIncludingProtectionSchemes().size(),
                 getProtectedPropertyKeys().size(), this.getClass().getName());
     }

     /**
      * Returns the sibling property key which specifies the protection scheme for this key.
      * <p>
      * Example:
      * <p>
      * nifi.sensitive.key=ABCXYZ
      * nifi.sensitive.key.protected=aes/gcm/256
      * <p>
      * nifi.sensitive.key -> nifi.sensitive.key.protected
      *
      * @param key the key identifying the sensitive property
      * @return the key identifying the protection scheme for the sensitive property
      */
     public static String getProtectionKey(final String key) {
         if (key == null || key.isEmpty()) {
             throw new IllegalArgumentException("Cannot find protection key for null key");
         }

         return key + PROTECTED_KEY_SUFFIX;
     }

     /**
      * Retrieves all known property keys.
      *
      * @return all known property keys
      */
     @Override
     public Set<String> getPropertyKeys() {
         Set<String> filteredKeys = getPropertyKeysIncludingProtectionSchemes();
         filteredKeys.removeIf(p -> p.endsWith(PROTECTED_KEY_SUFFIX));
         return filteredKeys;
     }

     @Override
     public int size() {
         return getPropertyKeys().size();
     }

     @Override
     public Set<String> getPropertyKeysIncludingProtectionSchemes() {
         return protectedProperties.getApplicationProperties().getPropertyKeys();
     }

     /**
      * Splits a single string containing multiple property keys into a List. Delimited by ',' or ';' and ignores leading and trailing whitespace around delimiter.
      *
      * @param multipleProperties a single String containing multiple properties, i.e. "nifi.property.1; nifi.property.2, nifi.property.3"
      * @return a List containing the split and trimmed properties
      */
     private static List<String> splitMultipleProperties(final String multipleProperties) {
         if (multipleProperties == null || multipleProperties.trim().isEmpty()) {
             return new ArrayList<>(0);
         } else {
             List<String> properties = new ArrayList<>(asList(multipleProperties.split("\\s*[,;]\\s*")));
             for (int i = 0; i < properties.size(); i++) {
                 properties.set(i, properties.get(i).trim());
             }
             return properties;
         }
     }

     private String getProperty(final String key) {
         return protectedProperties.getApplicationProperties().getProperty(key);
     }

     private String getAdditionalSensitivePropertiesKeys() {
         return getProperty(protectedProperties.getAdditionalSensitivePropertiesKeysName());
     }

     private String getAdditionalSensitivePropertiesKeysName() {
         return protectedProperties.getAdditionalSensitivePropertiesKeysName();
     }

     @Override
     public List<String> getSensitivePropertyKeys() {
         final String additionalPropertiesString = getAdditionalSensitivePropertiesKeys();
         final String additionalPropertiesKeyName = protectedProperties.getAdditionalSensitivePropertiesKeysName();
         if (additionalPropertiesString == null || additionalPropertiesString.trim().isEmpty()) {
             return protectedProperties.getDefaultSensitiveProperties();
         } else {
             List<String> additionalProperties = splitMultipleProperties(additionalPropertiesString);
             /* Remove this key if it was accidentally provided as a sensitive key
              * because we cannot protect it and read from it
             */
             if (additionalProperties.contains(additionalPropertiesKeyName)) {
                 logger.warn("The key '{}' contains itself. This is poor practice and should be removed", additionalPropertiesKeyName);
                 additionalProperties.remove(additionalPropertiesKeyName);
             }
             additionalProperties.addAll(protectedProperties.getDefaultSensitiveProperties());
             return additionalProperties;
         }
     }

     @Override
     public List<String> getPopulatedSensitivePropertyKeys() {
         List<String> allSensitiveKeys = getSensitivePropertyKeys();
         return allSensitiveKeys.stream().filter(k -> StringUtils.isNotBlank(getProperty(k))).collect(Collectors.toList());
     }

     @Override
     public boolean hasProtectedKeys() {
         final List<String> sensitiveKeys = getSensitivePropertyKeys();
         for (String k : sensitiveKeys) {
             if (isPropertyProtected(k)) {
                 return true;
             }
         }
         return false;
     }

     @Override
     public Map<String, String> getProtectedPropertyKeys() {
         final List<String> sensitiveKeys = getSensitivePropertyKeys();

         final Map<String, String> traditionalProtectedProperties = new HashMap<>();
         for (final String key : sensitiveKeys) {
             final String protection = getProperty(getProtectionKey(key));
             if (StringUtils.isNotBlank(protection) && StringUtils.isNotBlank(getProperty(key))) {
                 traditionalProtectedProperties.put(key, protection);
             }
         }

         return traditionalProtectedProperties;
     }

     @Override
     public Set<String> getProtectionSchemes() {
         return new HashSet<>(getProtectedPropertyKeys().values());
     }

     @Override
     public boolean isPropertySensitive(final String key) {
         // If the explicit check for ADDITIONAL_SENSITIVE_PROPERTIES_KEY is not here, this will loop infinitely
         return key != null && !key.equals(getAdditionalSensitivePropertiesKeysName()) && getSensitivePropertyKeys().contains(key.trim());
     }

     /**
      * Returns true if the property identified by this key is considered protected in this instance of {@code NiFiProperties}.
      * The property value is protected if the key is sensitive and the sibling key of key.protected is present.
      *
      * @param key the key
      * @return true if it is currently marked as protected
      * @see ApplicationPropertiesProtector#getSensitivePropertyKeys()
      */
     @Override
     public boolean isPropertyProtected(final String key) {
         return key != null && isPropertySensitive(key) && !StringUtils.isBlank(getProperty(getProtectionKey(key)));
     }

     @Override
     public U getUnprotectedProperties() throws SensitivePropertyProtectionException {
         if (hasProtectedKeys()) {
             logger.debug("Protected Properties [{}] Sensitive Properties [{}]",
                     getProtectedPropertyKeys().size(),
                     getSensitivePropertyKeys().size());

             final Properties rawProperties = new Properties();

             final Set<String> failedKeys = new HashSet<>();

             for (final String key : getPropertyKeys()) {
                 /* Three kinds of keys
                  * 1. protection schemes -- skip
                  * 2. protected keys -- unprotect and copy
                  * 3. normal keys -- copy over
                  */
                 if (key.endsWith(PROTECTED_KEY_SUFFIX)) {
                     // Do nothing
                 } else if (isPropertyProtected(key)) {
                     try {
                         rawProperties.setProperty(key, unprotectValue(key, getProperty(key)));
                     } catch (final SensitivePropertyProtectionException e) {
                         logger.warn("Failed to unprotect '{}'", key, e);
                         failedKeys.add(key);
                     }
                 } else {
                     rawProperties.setProperty(key, getProperty(key));
                 }
             }

             if (!failedKeys.isEmpty()) {
                 if (failedKeys.size() > 1) {
                     logger.warn("Combining {} failed keys [{}] into single exception", failedKeys.size(), StringUtils.join(failedKeys, ", "));
                     throw new MultipleSensitivePropertyProtectionException("Failed to unprotect keys", failedKeys);
                 } else {
                     throw new SensitivePropertyProtectionException("Failed to unprotect key " + failedKeys.iterator().next());
                 }
             }

             final U unprotected = protectedProperties.createApplicationProperties(rawProperties);

             return unprotected;
         } else {
             logger.debug("No protected properties");
             return protectedProperties.getApplicationProperties();
         }
     }

     @Override
     public void addSensitivePropertyProvider(final SensitivePropertyProvider sensitivePropertyProvider) {
         Objects.requireNonNull(sensitivePropertyProvider, "Cannot add null SensitivePropertyProvider");
         if (sensitivePropertyProvider == null) {
             throw new IllegalArgumentException("Cannot add null SensitivePropertyProvider");
         }

         if (getSensitivePropertyProviders().containsKey(sensitivePropertyProvider.getIdentifierKey())) {
             throw new UnsupportedOperationException("Cannot overwrite existing sensitive property provider registered for " + sensitivePropertyProvider.getIdentifierKey());
         }

         getSensitivePropertyProviders().put(sensitivePropertyProvider.getIdentifierKey(), sensitivePropertyProvider);
     }

     @Override
     public String toString() {
         final Set<String> providers = getSensitivePropertyProviders().keySet();
         return new StringBuilder("ApplicationPropertiesProtector instance with ")
                 .append(size()).append(" properties (")
                 .append(getProtectedPropertyKeys().size())
                 .append(" protected) and ")
                 .append(providers.size())
                 .append(" sensitive property providers: ")
                 .append(StringUtils.join(providers, ", "))
                 .toString();
     }

     @Override
     public Map<String, SensitivePropertyProvider> getSensitivePropertyProviders() {
         if (localProviderCache == null) {
             localProviderCache = new HashMap<>();
         }

         return localProviderCache;
     }

     private SensitivePropertyProvider getSensitivePropertyProvider(final String protectionScheme) {
         if (isProviderAvailable(protectionScheme)) {
             return getSensitivePropertyProviders().get(protectionScheme);
         } else {
             throw new SensitivePropertyProtectionException("No provider available for " + protectionScheme);
         }
     }

     private boolean isProviderAvailable(final String protectionScheme) {
         return getSensitivePropertyProviders().containsKey(protectionScheme);
     }

     /**
      * If the value is protected, unprotects it and returns it. If not, returns the original value.
      *
      * @param key            the retrieved property key
      * @param retrievedValue the retrieved property value
      * @return the unprotected value
      */
     private String unprotectValue(final String key, final String retrievedValue) {
         // Checks if the key is sensitive and marked as protected
         if (isPropertyProtected(key)) {
             final String protectionScheme = getProperty(getProtectionKey(key));

             // No provider registered for this scheme
             if (!isProviderAvailable(protectionScheme)) {
                 throw new IllegalStateException(String.format("No provider available for " + key));
             }

             try {
                 final SensitivePropertyProvider sensitivePropertyProvider = getSensitivePropertyProvider(protectionScheme);
                 return sensitivePropertyProvider.unprotect(retrievedValue);
             } catch (SensitivePropertyProtectionException e) {
                 logger.error("Error unprotecting value for " + key, e);
                 throw e;
             } catch (IllegalArgumentException e) {
                 throw new SensitivePropertyProtectionException("Error unprotecting value for " + key, e);
             }
         }
         return retrievedValue;
     }
 }
	/*
	* 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.nifi.properties;

	import org.apache.commons.lang3.StringUtils;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import java.util.Properties;
	import java.util.Set;
	import java.util.stream.Collectors;

	import static java.util.Arrays.asList;

	/**
	* Class performing unprotection activities before returning a clean
	* implementation of {@link ApplicationProperties}.
	* This encapsulates the sensitive property access logic from external consumers
	* of {@code ApplicationProperties}.
	*
	* @param <T> The type of protected application properties
	* @param <U> The type of standard application properties that backs the protected application properties
	*/
	public class ApplicationPropertiesProtector<T extends ProtectedProperties<U>, U extends ApplicationProperties>
	implements SensitivePropertyProtector<T, U> {
	public static final String PROTECTED_KEY_SUFFIX = ".protected";

	private static final Logger logger = LoggerFactory.getLogger(ApplicationPropertiesProtector.class);

	private T protectedProperties;

	private Map<String, SensitivePropertyProvider> localProviderCache = new HashMap<>();

	/**
	* Creates an instance containing the provided {@link ProtectedProperties}.
	*
	* @param protectedProperties the ProtectedProperties to contain
	*/
	public ApplicationPropertiesProtector(final T protectedProperties) {
	this.protectedProperties = protectedProperties;
	logger.debug("Loaded {} properties (including {} protection schemes) into {}", getPropertyKeysIncludingProtectionSchemes().size(),
	getProtectedPropertyKeys().size(), this.getClass().getName());
	}

	/**
	* Returns the sibling property key which specifies the protection scheme for this key.
	* <p>
	* Example:
	* <p>
	* nifi.sensitive.key=ABCXYZ
	* nifi.sensitive.key.protected=aes/gcm/256
	* <p>
	* nifi.sensitive.key -> nifi.sensitive.key.protected
	*
	* @param key the key identifying the sensitive property
	* @return the key identifying the protection scheme for the sensitive property
	*/
	public static String getProtectionKey(final String key) {
	if (key == null \|\| key.isEmpty()) {
	throw new IllegalArgumentException("Cannot find protection key for null key");
	}

	return key + PROTECTED_KEY_SUFFIX;
	}

	/**
	* Retrieves all known property keys.
	*
	* @return all known property keys
	*/
	@Override
	public Set<String> getPropertyKeys() {
	Set<String> filteredKeys = getPropertyKeysIncludingProtectionSchemes();
	filteredKeys.removeIf(p -> p.endsWith(PROTECTED_KEY_SUFFIX));
	return filteredKeys;
	}

	@Override
	public int size() {
	return getPropertyKeys().size();
	}

	@Override
	public Set<String> getPropertyKeysIncludingProtectionSchemes() {
	return protectedProperties.getApplicationProperties().getPropertyKeys();
	}

	/**
	* Splits a single string containing multiple property keys into a List. Delimited by ',' or ';' and ignores leading and trailing whitespace around delimiter.
	*
	* @param multipleProperties a single String containing multiple properties, i.e. "nifi.property.1; nifi.property.2, nifi.property.3"
	* @return a List containing the split and trimmed properties
	*/
	private static List<String> splitMultipleProperties(final String multipleProperties) {
	if (multipleProperties == null \|\| multipleProperties.trim().isEmpty()) {
	return new ArrayList<>(0);
	} else {
	List<String> properties = new ArrayList<>(asList(multipleProperties.split("\\s[,;]\\s")));
	for (int i = 0; i < properties.size(); i++) {
	properties.set(i, properties.get(i).trim());
	}
	return properties;
	}
	}

	private String getProperty(final String key) {
	return protectedProperties.getApplicationProperties().getProperty(key);
	}

	private String getAdditionalSensitivePropertiesKeys() {
	return getProperty(protectedProperties.getAdditionalSensitivePropertiesKeysName());
	}

	private String getAdditionalSensitivePropertiesKeysName() {
	return protectedProperties.getAdditionalSensitivePropertiesKeysName();
	}

	@Override
	public List<String> getSensitivePropertyKeys() {
	final String additionalPropertiesString = getAdditionalSensitivePropertiesKeys();
	final String additionalPropertiesKeyName = protectedProperties.getAdditionalSensitivePropertiesKeysName();
	if (additionalPropertiesString == null \|\| additionalPropertiesString.trim().isEmpty()) {
	return protectedProperties.getDefaultSensitiveProperties();
	} else {
	List<String> additionalProperties = splitMultipleProperties(additionalPropertiesString);
	/* Remove this key if it was accidentally provided as a sensitive key
	* because we cannot protect it and read from it
	*/
	if (additionalProperties.contains(additionalPropertiesKeyName)) {
	logger.warn("The key '{}' contains itself. This is poor practice and should be removed", additionalPropertiesKeyName);
	additionalProperties.remove(additionalPropertiesKeyName);
	}
	additionalProperties.addAll(protectedProperties.getDefaultSensitiveProperties());
	return additionalProperties;
	}
	}

	@Override
	public List<String> getPopulatedSensitivePropertyKeys() {
	List<String> allSensitiveKeys = getSensitivePropertyKeys();
	return allSensitiveKeys.stream().filter(k -> StringUtils.isNotBlank(getProperty(k))).collect(Collectors.toList());
	}

	@Override
	public boolean hasProtectedKeys() {
	final List<String> sensitiveKeys = getSensitivePropertyKeys();
	for (String k : sensitiveKeys) {
	if (isPropertyProtected(k)) {
	return true;
	}
	}
	return false;
	}

	@Override
	public Map<String, String> getProtectedPropertyKeys() {
	final List<String> sensitiveKeys = getSensitivePropertyKeys();

	final Map<String, String> traditionalProtectedProperties = new HashMap<>();
	for (final String key : sensitiveKeys) {
	final String protection = getProperty(getProtectionKey(key));
	if (StringUtils.isNotBlank(protection) && StringUtils.isNotBlank(getProperty(key))) {
	traditionalProtectedProperties.put(key, protection);
	}
	}

	return traditionalProtectedProperties;
	}

	@Override
	public Set<String> getProtectionSchemes() {
	return new HashSet<>(getProtectedPropertyKeys().values());
	}

	@Override
	public boolean isPropertySensitive(final String key) {
	// If the explicit check for ADDITIONAL_SENSITIVE_PROPERTIES_KEY is not here, this will loop infinitely
	return key != null && !key.equals(getAdditionalSensitivePropertiesKeysName()) && getSensitivePropertyKeys().contains(key.trim());
	}

	/**
	* Returns true if the property identified by this key is considered protected in this instance of {@code NiFiProperties}.
	* The property value is protected if the key is sensitive and the sibling key of key.protected is present.
	*
	* @param key the key
	* @return true if it is currently marked as protected
	* @see ApplicationPropertiesProtector#getSensitivePropertyKeys()
	*/
	@Override
	public boolean isPropertyProtected(final String key) {
	return key != null && isPropertySensitive(key) && !StringUtils.isBlank(getProperty(getProtectionKey(key)));
	}

	@Override
	public U getUnprotectedProperties() throws SensitivePropertyProtectionException {
	if (hasProtectedKeys()) {
	logger.debug("Protected Properties [{}] Sensitive Properties [{}]",
	getProtectedPropertyKeys().size(),
	getSensitivePropertyKeys().size());

	final Properties rawProperties = new Properties();

	final Set<String> failedKeys = new HashSet<>();

	for (final String key : getPropertyKeys()) {
	/* Three kinds of keys
	* 1. protection schemes -- skip
	* 2. protected keys -- unprotect and copy
	* 3. normal keys -- copy over
	*/
	if (key.endsWith(PROTECTED_KEY_SUFFIX)) {
	// Do nothing
	} else if (isPropertyProtected(key)) {
	try {
	rawProperties.setProperty(key, unprotectValue(key, getProperty(key)));
	} catch (final SensitivePropertyProtectionException e) {
	logger.warn("Failed to unprotect '{}'", key, e);
	failedKeys.add(key);
	}
	} else {
	rawProperties.setProperty(key, getProperty(key));
	}
	}

	if (!failedKeys.isEmpty()) {
	if (failedKeys.size() > 1) {
	logger.warn("Combining {} failed keys [{}] into single exception", failedKeys.size(), StringUtils.join(failedKeys, ", "));
	throw new MultipleSensitivePropertyProtectionException("Failed to unprotect keys", failedKeys);
	} else {
	throw new SensitivePropertyProtectionException("Failed to unprotect key " + failedKeys.iterator().next());
	}
	}

	final U unprotected = protectedProperties.createApplicationProperties(rawProperties);

	return unprotected;
	} else {
	logger.debug("No protected properties");
	return protectedProperties.getApplicationProperties();
	}
	}

	@Override
	public void addSensitivePropertyProvider(final SensitivePropertyProvider sensitivePropertyProvider) {
	Objects.requireNonNull(sensitivePropertyProvider, "Cannot add null SensitivePropertyProvider");
	if (sensitivePropertyProvider == null) {
	throw new IllegalArgumentException("Cannot add null SensitivePropertyProvider");
	}

	if (getSensitivePropertyProviders().containsKey(sensitivePropertyProvider.getIdentifierKey())) {
	throw new UnsupportedOperationException("Cannot overwrite existing sensitive property provider registered for " + sensitivePropertyProvider.getIdentifierKey());
	}

	getSensitivePropertyProviders().put(sensitivePropertyProvider.getIdentifierKey(), sensitivePropertyProvider);
	}

	@Override
	public String toString() {
	final Set<String> providers = getSensitivePropertyProviders().keySet();
	return new StringBuilder("ApplicationPropertiesProtector instance with ")
	.append(size()).append(" properties (")
	.append(getProtectedPropertyKeys().size())
	.append(" protected) and ")
	.append(providers.size())
	.append(" sensitive property providers: ")
	.append(StringUtils.join(providers, ", "))
	.toString();
	}

	@Override
	public Map<String, SensitivePropertyProvider> getSensitivePropertyProviders() {
	if (localProviderCache == null) {
	localProviderCache = new HashMap<>();
	}

	return localProviderCache;
	}

	private SensitivePropertyProvider getSensitivePropertyProvider(final String protectionScheme) {
	if (isProviderAvailable(protectionScheme)) {
	return getSensitivePropertyProviders().get(protectionScheme);
	} else {
	throw new SensitivePropertyProtectionException("No provider available for " + protectionScheme);
	}
	}

	private boolean isProviderAvailable(final String protectionScheme) {
	return getSensitivePropertyProviders().containsKey(protectionScheme);
	}

	/**
	* If the value is protected, unprotects it and returns it. If not, returns the original value.
	*
	* @param key the retrieved property key
	* @param retrievedValue the retrieved property value
	* @return the unprotected value
	*/
	private String unprotectValue(final String key, final String retrievedValue) {
	// Checks if the key is sensitive and marked as protected
	if (isPropertyProtected(key)) {
	final String protectionScheme = getProperty(getProtectionKey(key));

	// No provider registered for this scheme
	if (!isProviderAvailable(protectionScheme)) {
	throw new IllegalStateException(String.format("No provider available for " + key));
	}

	try {
	final SensitivePropertyProvider sensitivePropertyProvider = getSensitivePropertyProvider(protectionScheme);
	return sensitivePropertyProvider.unprotect(retrievedValue);
	} catch (SensitivePropertyProtectionException e) {
	logger.error("Error unprotecting value for " + key, e);
	throw e;
	} catch (IllegalArgumentException e) {
	throw new SensitivePropertyProtectionException("Error unprotecting value for " + key, e);
	}
	}
	return retrievedValue;
	}
	}