org.opensaml.saml.saml2.encryption.Encrypter Maven / Gradle / Ivy
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* Licensed to the University Corporation for Advanced Internet Development,
* Inc. (UCAID) under one or more contributor license agreements. See the
* NOTICE file distributed with this work for additional information regarding
* copyright ownership. The UCAID 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.opensaml.saml.saml2.encryption;
import java.security.Key;
import java.util.ArrayList;
import java.util.List;
import javax.xml.namespace.QName;
import net.shibboleth.utilities.java.support.security.IdentifierGenerationStrategy;
import net.shibboleth.utilities.java.support.security.RandomIdentifierGenerationStrategy;
import net.shibboleth.utilities.java.support.xml.SerializeSupport;
import org.opensaml.core.xml.XMLObject;
import org.opensaml.core.xml.XMLObjectBuilderFactory;
import org.opensaml.core.xml.config.XMLObjectProviderRegistrySupport;
import org.opensaml.core.xml.io.MarshallingException;
import org.opensaml.core.xml.util.XMLObjectSupport;
import org.opensaml.saml.saml2.core.Assertion;
import org.opensaml.saml.saml2.core.Attribute;
import org.opensaml.saml.saml2.core.BaseID;
import org.opensaml.saml.saml2.core.EncryptedAssertion;
import org.opensaml.saml.saml2.core.EncryptedAttribute;
import org.opensaml.saml.saml2.core.EncryptedElementType;
import org.opensaml.saml.saml2.core.EncryptedID;
import org.opensaml.saml.saml2.core.NameID;
import org.opensaml.saml.saml2.core.NewEncryptedID;
import org.opensaml.saml.saml2.core.NewID;
import org.opensaml.security.SecurityException;
import org.opensaml.security.credential.CredentialSupport;
import org.opensaml.xmlsec.encryption.CarriedKeyName;
import org.opensaml.xmlsec.encryption.DataReference;
import org.opensaml.xmlsec.encryption.EncryptedData;
import org.opensaml.xmlsec.encryption.EncryptedKey;
import org.opensaml.xmlsec.encryption.ReferenceList;
import org.opensaml.xmlsec.encryption.XMLEncryptionBuilder;
import org.opensaml.xmlsec.encryption.support.EncryptionConstants;
import org.opensaml.xmlsec.encryption.support.EncryptionException;
import org.opensaml.xmlsec.encryption.support.DataEncryptionParameters;
import org.opensaml.xmlsec.encryption.support.KeyEncryptionParameters;
import org.opensaml.xmlsec.keyinfo.KeyInfoGenerator;
import org.opensaml.xmlsec.signature.KeyInfo;
import org.opensaml.xmlsec.signature.KeyName;
import org.opensaml.xmlsec.signature.RetrievalMethod;
import org.opensaml.xmlsec.signature.XMLSignatureBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import com.google.common.base.Strings;
/**
* Encrypter for SAML 2 SAMLObjects which has specific options for generating instances of subtypes of
* {@link EncryptedElementType}.
*
*
* Overloaded methods are provided for encrypting various SAML 2 elements to their corresponding encrypted element
* variant of {@link EncryptedElementType}.
*
*
*
* Support is also provided for differing placement options for any associated EncryptedKeys that may be generated. The
* options are:
*
* INLINE: EncryptedKeys will placed inside the KeyInfo element of the EncryptedData elementPEER: EncryptedKeys will be placed as peer elements of the EncryptedData inside the
* EncryptedElementType element
* The default placement is PEER.
*
*
*
* The EncryptedKey forward and back referencing behavior associated with these key placement options is intended to be
* consistent with the guidelines detailed in SAML 2 Errata E43. See that document for further information.
*
*
*
* For information on other parameters and options, and general XML Encryption issues, see
* {@link org.opensaml.xmlsec.encryption.support.Encrypter}.
*
*
*/
public class Encrypter extends org.opensaml.xmlsec.encryption.support.Encrypter {
/**
* Options for where to place the resulting EncryptedKey elements with respect to the associated EncryptedData
* element.
*/
public enum KeyPlacement {
/** Place the EncryptedKey element(s) as a peer to the EncryptedData inside the EncryptedElementType. */
PEER,
/** Place the EncryptedKey element(s) within the KeyInfo of the EncryptedData. */
INLINE
}
/** Factory for building XMLObject instances. */
private XMLObjectBuilderFactory builderFactory;
/** Builder for KeyInfo objects. */
private XMLSignatureBuilder keyInfoBuilder;
/** Builder for DataReference objects. */
private XMLEncryptionBuilder dataReferenceBuilder;
/** Builder for ReferenceList objects. */
private XMLEncryptionBuilder referenceListBuilder;
/** Builder for RetrievalMethod objects. */
private XMLSignatureBuilder retrievalMethodBuilder;
/** Builder for KeyName objects. */
private XMLSignatureBuilder keyNameBuilder;
/** Builder for CarriedKeyName objects. */
private XMLEncryptionBuilder carriedKeyNameBuilder;
/** Generator for XML ID attribute values. */
private IdentifierGenerationStrategy idGenerator;
/** The parameters to use for encrypting the data. */
private DataEncryptionParameters encParams;
/** The parameters to use for encrypting (wrapping) the data encryption key. */
private List kekParamsList;
/** The option for where to place the generated EncryptedKey elements. */
private KeyPlacement keyPlacement;
/** Class logger. */
private final Logger log = LoggerFactory.getLogger(Encrypter.class);
/**
* Constructor.
*
* @param dataEncParams the data encryption parameters
* @param keyEncParams the key encryption parameters
*/
public Encrypter(final DataEncryptionParameters dataEncParams, final List keyEncParams) {
super();
this.encParams = dataEncParams;
this.kekParamsList = keyEncParams;
init();
}
/**
* Constructor.
*
* @param dataEncParams the data encryption parameters
* @param keyEncParam the key encryption parameter
*/
public Encrypter(final DataEncryptionParameters dataEncParams, final KeyEncryptionParameters keyEncParam) {
super();
final List keks = new ArrayList<>();
keks.add(keyEncParam);
this.encParams = dataEncParams;
this.kekParamsList = keks;
init();
}
/**
* Constructor.
*
* @param dataEncParams the data encryption parameters
*/
public Encrypter(final DataEncryptionParameters dataEncParams) {
super();
final List keks = new ArrayList<>();
this.encParams = dataEncParams;
this.kekParamsList = keks;
init();
}
/**
* Helper method for constructors.
*/
private void init() {
builderFactory = XMLObjectProviderRegistrySupport.getBuilderFactory();
keyInfoBuilder = (XMLSignatureBuilder) builderFactory.getBuilder(KeyInfo.DEFAULT_ELEMENT_NAME);
dataReferenceBuilder =
(XMLEncryptionBuilder) builderFactory.getBuilder(DataReference.DEFAULT_ELEMENT_NAME);
referenceListBuilder =
(XMLEncryptionBuilder) builderFactory.getBuilder(ReferenceList.DEFAULT_ELEMENT_NAME);
retrievalMethodBuilder =
(XMLSignatureBuilder) builderFactory.getBuilder(RetrievalMethod.DEFAULT_ELEMENT_NAME);
keyNameBuilder = (XMLSignatureBuilder) builderFactory.getBuilder(KeyName.DEFAULT_ELEMENT_NAME);
carriedKeyNameBuilder =
(XMLEncryptionBuilder) builderFactory.getBuilder(CarriedKeyName.DEFAULT_ELEMENT_NAME);
idGenerator = new RandomIdentifierGenerationStrategy();
keyPlacement = KeyPlacement.PEER;
}
/**
* Set the generator to use when creating XML ID attribute values.
*
* @param newIDGenerator the new IdentifierGenerator to use
*/
public void setIDGenerator(final IdentifierGenerationStrategy newIDGenerator) {
this.idGenerator = newIDGenerator;
}
/**
* Get the current key placement option.
*
* @return returns the key placement option.
*/
public KeyPlacement getKeyPlacement() {
return this.keyPlacement;
}
/**
* Set the key placement option.
*
* @param newKeyPlacement The new key placement option to set
*/
public void setKeyPlacement(final KeyPlacement newKeyPlacement) {
this.keyPlacement = newKeyPlacement;
}
/**
* Encrypt the specified Assertion.
*
* @param assertion the Assertion to encrypt
* @return an EncryptedAssertion
* @throws EncryptionException thrown when encryption generates an error
*/
public EncryptedAssertion encrypt(final Assertion assertion) throws EncryptionException {
logPreEncryption(assertion, "Assertion");
return (EncryptedAssertion) encrypt(assertion, EncryptedAssertion.DEFAULT_ELEMENT_NAME);
}
/**
* Encrypt the specified Assertion, treating as an identifier and returning an EncryptedID.
*
* @param assertion the Assertion to encrypt
* @return an EncryptedID
* @throws EncryptionException thrown when encryption generates an error
*/
public EncryptedID encryptAsID(final Assertion assertion) throws EncryptionException {
logPreEncryption(assertion, "Assertion (as EncryptedID)");
return (EncryptedID) encrypt(assertion, EncryptedID.DEFAULT_ELEMENT_NAME);
}
/**
* Encrypt the specified Attribute.
*
* @param attribute the Attribute to encrypt
* @return an EncryptedAttribute
* @throws EncryptionException thrown when encryption generates an error
*/
public EncryptedAttribute encrypt(final Attribute attribute) throws EncryptionException {
logPreEncryption(attribute, "Attribute");
return (EncryptedAttribute) encrypt(attribute, EncryptedAttribute.DEFAULT_ELEMENT_NAME);
}
/**
* Encrypt the specified NameID.
*
* @param nameID the NameID to encrypt
* @return an EncryptedID
* @throws EncryptionException thrown when encryption generates an error
*/
public EncryptedID encrypt(final NameID nameID) throws EncryptionException {
logPreEncryption(nameID, "NameID");
return (EncryptedID) encrypt(nameID, EncryptedID.DEFAULT_ELEMENT_NAME);
}
/**
* Encrypt the specified BaseID.
*
* @param baseID the BaseID to encrypt
* @return an EncryptedID
* @throws EncryptionException thrown when encryption generates an error
*/
public EncryptedID encrypt(final BaseID baseID) throws EncryptionException {
logPreEncryption(baseID, "BaseID");
return (EncryptedID) encrypt(baseID, EncryptedID.DEFAULT_ELEMENT_NAME);
}
/**
* Encrypt the specified NewID.
*
* @param newID the NewID to encrypt
* @return a NewEncryptedID
* @throws EncryptionException thrown when encryption generates an error
*/
public NewEncryptedID encrypt(final NewID newID) throws EncryptionException {
logPreEncryption(newID, "NewID");
return (NewEncryptedID) encrypt(newID, NewEncryptedID.DEFAULT_ELEMENT_NAME);
}
/**
* Log the target object prior to encryption.
*
* @param xmlObject the XMLObject to encrypt
* @param objectType String description of the type of object to encrypt
*/
private void logPreEncryption(final XMLObject xmlObject, final String objectType) {
if (log.isDebugEnabled()) {
try {
final Element dom = XMLObjectSupport.marshall(xmlObject);
log.debug("{} before encryption:\n{}", objectType, SerializeSupport.prettyPrintXML(dom));
} catch (final MarshallingException e) {
log.error("Unable to marshall {} for logging purposes", objectType, e);
}
}
}
/**
* Encrypt the specified XMLObject, and return it as an instance of the specified QName, which should be one of the
* types derived from {@link org.opensaml.saml.saml2.core.EncryptedElementType}.
*
* @param xmlObject the XMLObject to encrypt
* @param encElementName the QName of the specialization of EncryptedElementType to return
* @return a specialization of {@link org.opensaml.saml.saml2.core.EncryptedElementType}
* @throws EncryptionException thrown when encryption generates an error
*/
private EncryptedElementType encrypt(final XMLObject xmlObject, final QName encElementName)
throws EncryptionException {
checkParams(encParams, kekParamsList);
final EncryptedElementType encElement =
(EncryptedElementType) builderFactory.getBuilder(encElementName).buildObject(encElementName);
// Marshall the containing element, we will need its Document context to pass
// to the key encryption method
checkAndMarshall(encElement);
final Document ownerDocument = encElement.getDOM().getOwnerDocument();
final String encryptionAlgorithmURI = encParams.getAlgorithm();
Key encryptionKey = CredentialSupport.extractEncryptionKey(encParams.getEncryptionCredential());
if (encryptionKey == null) {
encryptionKey = generateEncryptionKey(encryptionAlgorithmURI);
}
final EncryptedData encryptedData = encryptElement(xmlObject, encryptionKey, encryptionAlgorithmURI, false);
if (encParams.getKeyInfoGenerator() != null) {
final KeyInfoGenerator generator = encParams.getKeyInfoGenerator();
log.debug("Dynamically generating KeyInfo from Credential for EncryptedData using generator: {}", generator
.getClass().getName());
try {
encryptedData.setKeyInfo(generator.generate(encParams.getEncryptionCredential()));
} catch (final SecurityException e) {
throw new EncryptionException("Error generating EncryptedData KeyInfo", e);
}
}
final List encryptedKeys = new ArrayList<>();
if (kekParamsList != null && !kekParamsList.isEmpty()) {
encryptedKeys.addAll(encryptKey(encryptionKey, kekParamsList, ownerDocument));
}
return processElements(encElement, encryptedData, encryptedKeys);
}
/**
* Handle post-processing of generated EncryptedData and EncryptedKey(s) and storage in the appropriate
* EncryptedElementType instance.
*
* @param encElement the EncryptedElementType instance which will hold the encrypted data and keys
* @param encData the EncryptedData object
* @param encKeys the list of EncryptedKey objects
* @return the processed EncryptedElementType instance
*
* @throws EncryptionException thrown when processing encounters an error
*/
protected EncryptedElementType processElements(final EncryptedElementType encElement, final EncryptedData encData,
final List encKeys) throws EncryptionException {
// First ensure certain elements/attributes are non-null, common to all cases.
if (encData.getID() == null) {
encData.setID(idGenerator.generateIdentifier());
}
// If not doing key wrapping, just return the encrypted element
if (encKeys.isEmpty()) {
encElement.setEncryptedData(encData);
return encElement;
}
if (encData.getKeyInfo() == null) {
encData.setKeyInfo(keyInfoBuilder.buildObject());
}
for (final EncryptedKey encKey : encKeys) {
if (encKey.getID() == null) {
encKey.setID(idGenerator.generateIdentifier());
}
}
switch (keyPlacement) {
case INLINE:
return placeKeysInline(encElement, encData, encKeys);
case PEER:
return placeKeysAsPeers(encElement, encData, encKeys);
default:
// Shouldn't be able to get here, but just in case...
throw new EncryptionException("Unsupported key placement option was specified: " + keyPlacement);
}
}
/**
* Place the EncryptedKey elements inside the KeyInfo element within the EncryptedData element.
*
* Although operationally trivial, this method is provided so that subclasses may override or augment as desired.
*
* @param encElement the EncryptedElementType instance which will hold the encrypted data and keys
* @param encData the EncryptedData object
* @param encKeys the list of EncryptedKey objects
* @return the processed EncryptedElementType instance
*/
protected EncryptedElementType placeKeysInline(final EncryptedElementType encElement, final EncryptedData encData,
final List encKeys) {
log.debug("Placing EncryptedKey elements inline inside EncryptedData");
encData.getKeyInfo().getEncryptedKeys().addAll(encKeys);
encElement.setEncryptedData(encData);
return encElement;
}
/**
* Store the specified EncryptedData and EncryptedKey(s) in the specified instance of EncryptedElementType as peer
* elements, following SAML 2 Errata E43 guidelines for forward and back referencing between the EncryptedData and
* EncryptedKey(s).
*
* @param encElement a specialization of EncryptedElementType to store the encrypted data and keys
* @param encData the EncryptedData to store
* @param encKeys the EncryptedKey(s) to store
* @return the resulting specialization of EncryptedElementType
*/
protected EncryptedElementType placeKeysAsPeers(final EncryptedElementType encElement, final EncryptedData encData,
final List encKeys) {
log.debug("Placing EncryptedKey elements as peers of EncryptedData in EncryptedElementType");
for (final EncryptedKey encKey : encKeys) {
if (encKey.getReferenceList() == null) {
encKey.setReferenceList(referenceListBuilder.buildObject());
}
}
// If there is only 1 EncryptedKey we have a simple forward reference (RetrievalMethod)
// and back reference (ReferenceList/DataReference) requirement.
// Multiple "multicast" keys use back reference + CarriedKeyName
if (encKeys.size() == 1) {
linkSinglePeerKey(encData, encKeys.get(0));
} else if (encKeys.size() > 1) {
linkMultiplePeerKeys(encData, encKeys);
}
encElement.setEncryptedData(encData);
encElement.getEncryptedKeys().addAll(encKeys);
return encElement;
}
/**
* Link a single EncryptedKey to the EncryptedData according to guidelines in SAML Errata E43.
*
* @param encData the EncryptedData
* @param encKey the EncryptedKey
*/
protected void linkSinglePeerKey(final EncryptedData encData, final EncryptedKey encKey) {
log.debug("Linking single peer EncryptedKey with RetrievalMethod and DataReference");
// Forward reference from EncryptedData to the EncryptedKey
final RetrievalMethod rm = retrievalMethodBuilder.buildObject();
rm.setURI("#" + encKey.getID());
rm.setType(EncryptionConstants.TYPE_ENCRYPTED_KEY);
encData.getKeyInfo().getRetrievalMethods().add(rm);
// Back reference from the EncryptedKey to the EncryptedData
final DataReference dr = dataReferenceBuilder.buildObject();
dr.setURI("#" + encData.getID());
encKey.getReferenceList().getDataReferences().add(dr);
}
/**
* Link multiple "multicast" EncryptedKeys to the EncryptedData according to guidelines in SAML Errata E43.
*
* @param encData the EncryptedData
* @param encKeys the list of EncryptedKeys
*/
protected void linkMultiplePeerKeys(final EncryptedData encData, final List encKeys) {
log.debug("Linking multiple peer EncryptedKeys with CarriedKeyName and DataReference");
// Get the name of the data encryption key
final List dataEncKeyNames = encData.getKeyInfo().getKeyNames();
final String carriedKeyNameValue;
if (dataEncKeyNames.size() == 0 || Strings.isNullOrEmpty(dataEncKeyNames.get(0).getValue())) {
// If there isn't one, autogenerate a random key name.
final String keyNameValue = idGenerator.generateIdentifier();
log.debug("EncryptedData encryption key had no KeyName, generated one for use in CarriedKeyName: {}",
keyNameValue);
KeyName keyName = dataEncKeyNames.get(0);
if (keyName == null) {
keyName = keyNameBuilder.buildObject();
dataEncKeyNames.add(keyName);
}
keyName.setValue(keyNameValue);
carriedKeyNameValue = keyNameValue;
} else {
carriedKeyNameValue = dataEncKeyNames.get(0).getValue();
}
// Set carried key name of the multicast key in each EncryptedKey
for (final EncryptedKey encKey : encKeys) {
if (encKey.getCarriedKeyName() == null) {
encKey.setCarriedKeyName(carriedKeyNameBuilder.buildObject());
}
encKey.getCarriedKeyName().setValue(carriedKeyNameValue);
// Back reference from the EncryptedKeys to the EncryptedData
final DataReference dr = dataReferenceBuilder.buildObject();
dr.setURI("#" + encData.getID());
encKey.getReferenceList().getDataReferences().add(dr);
}
}
}
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