Chapter 345. XML Security Component

XML Signature differs between enveloped, enveloping, and detached XML signature. In the enveloped XML signature case, the XML Signature is wrapped by the signed XML Document; which means that the XML signature element is a child element of a parent element, which belongs to the signed XML Document. In the enveloping XML signature case, the XML Signature contains the signed content. All other cases are called detached XML signatures. A certain form of detached XML signature is supported since 2.14.0.

In the enveloped XML signature case, the supported generated XML signature has the following structure (Variables are surrounded by []).

<[parent element]>
   ... <!-- Signature element is added as last child of the parent element-->
   <Signature Id="generated_unique_signature_id">
       <SignedInfo>
             <Reference URI="">
                   <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
                   (<Transform>)* <!-- By default "http://www.w3.org/2006/12/xml-c14n11" is added to the transforms -->
                   <DigestMethod>
                   <DigestValue>
             </Reference>
             (<Reference URI="#[keyinfo_Id]">
                   <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
                   <DigestMethod>
                   <DigestValue>
             </Reference>)?
             <!-- further references possible, see option 'properties' below -->
      </SignedInfo>
      <SignatureValue>
      (<KeyInfo Id="[keyinfo_id]">)?
      <!-- Object elements possible, see option 'properties' below -->
  </Signature>
</[parent element]>

In the enveloping XML signature case, the supported generated XML signature has the structure:

<Signature Id="generated_unique_signature_id">
  <SignedInfo>
         <Reference URI="#generated_unique_object_id" type="[optional_type_value]">
               (<Transform>)* <!-- By default "http://www.w3.org/2006/12/xml-c14n11" is added to the transforms -->
               <DigestMethod>
               <DigestValue>
         </Reference>
         (<Reference URI="#[keyinfo_id]">
               <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
               <DigestMethod>
               <DigestValue>
         </Reference>)?
          <!-- further references possible, see option 'properties' below  -->
  </SignedInfo>
  <SignatureValue>
  (<KeyInfo Id="[keyinfo_id]">)?
  <Object Id="generated_unique_object_id"/> <!-- The Object element contains the in-message body; the object ID can either be generated or set by the option parameter "contentObjectId" -->
  <!-- Further Object elements possible, see option 'properties' below -->
</Signature>

As of 2.14.0 detached XML signatures with the following structure are supported (see also sub-chapter XML Signatures as Siblings of Signed Elements):

(<[signed element] Id="[id_value]">
<!-- signed element must have an attribute of type ID -->
      ...

</[signed element]>
<other sibling/>* 
<!-- between the signed element and the corresponding signature element, there can be other siblings.
 Signature element is added as last sibling. -->
<Signature Id="generated_unique_ID">
   <SignedInfo>
      <CanonicalizationMethod>
      <SignatureMethod>
      <Reference URI="#[id_value]" type="[optional_type_value]">
      <!-- reference URI contains the ID attribute value of the signed element -->
            (<Transform>)* <!-- By default "http://www.w3.org/2006/12/xml-c14n11" is added to the transforms -->
            <DigestMethod>
            <DigestValue>
      </Reference>
      (<Reference URI="#[generated_keyinfo_Id]">
            <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
            <DigestMethod>
            <DigestValue>
      </Reference>)?
   </SignedInfo>
   <SignatureValue>
   (<KeyInfo Id="[generated_keyinfo_id]">)?
</Signature>)+

The camel component consists of two endpoints which have the following URI format:

xmlsecurity:sign:name[?options]
xmlsecurity:verify:name[?options]

The following example shows the basic usage of the component.

from("direct:enveloping").to("xmlsecurity:sign://enveloping?keyAccessor=#accessor",
                             "xmlsecurity:verify://enveloping?keySelector=#selector",
                             "mock:result")

In Spring XML:

<from uri="direct:enveloping" />
    <to uri="xmlsecurity:sign://enveloping?keyAccessor=#accessor" />
    <to uri="xmlsecurity:verify://enveloping?keySelector=#selector" />
<to uri="mock:result" />

For the signing process, a private key is necessary. You specify a key accessor bean which provides this private key. For the validation, the corresponding public key is necessary; you specify a key selector bean which provides this public key.

The key accessor bean must implement the KeyAccessor interface. The package org.apache.camel.component.xmlsecurity.api contains the default implementation class DefaultKeyAccessor which reads the private key from a Java keystore.

The key selector bean must implement the javax.xml.crypto.KeySelector interface. The package org.apache.camel.component.xmlsecurity.api contains the default implementation class DefaultKeySelector which reads the public key from a keystore.

In the example, the default signature algorithm http://www.w3.org/2000/09/xmldsig#rsa-sha1 is used. You can set the signature algorithm of your choice by the option signatureAlgorithm (see below). The signer endpoint creates an enveloping XML signature. If you want to create an enveloped XML signature then you must specify the parent element of the Signature element; see option parentLocalName for more details.

For creating detached XML signatures, see sub-chapter "Detached XML Signatures as Siblings of the Signed Elements".

The XML Security component supports 3 options which are listed below.

The XML Security endpoint is configured using URI syntax:

xmlsecurity:command:name

with the following path and query parameters:

<Signature>
      <SignedInfo>
         <Reference URI="#object"/>
         <!-- further references possible but they must not point to an Object or Manifest containing an object reference -->
         ...
      </SignedInfo>

      <Object Id="object">
           <!-- contains one XML element which is extracted to the message body -->
      <Object>
      <!-- further object elements possible which are not referenced-->
      ...
      (<KeyInfo>)?
</Signature>

<Signature>
      <SignedInfo>
         <Reference URI="#manifest"/>
         <!-- further references  are possible but they must not point to an Object or other manifest containing an object reference -->
         ...
      </SignedInfo>

      <Object >
         <Manifest Id="manifest">
            <Reference URI=#object/>
         </Manifest>
      </Objet>
      <Object Id="object">
          <!-- contains the DOM node which is extracted to the message body -->
      </Object>
       <!-- further object elements possible which are not referenced -->
      ...
      (<KeyInfo>)?
</Signature>

Since 2.14.0

You can create detached signatures where the signature is a sibling of the signed element. The following example contains two detached signatures. The first signature is for the element C and the second signature is for element A. The signatures are nested; the second signature is for the element A which also contains the first signature.

Example Detached XML Signatures

<?xml version="1.0" encoding="UTF-8" ?>
<root>
    <A ID="IDforA">
        <B>
            <C ID="IDforC">
                <D>dvalue</D>
            </C>
            <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
                Id="_6bf13099-0568-4d76-8649-faf5dcb313c0">
                <ds:SignedInfo>
                    <ds:CanonicalizationMethod
                        Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
                    <ds:SignatureMethod
                        Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
                    <ds:Reference URI="#IDforC">
                        ...
                    </ds:Reference>
                </ds:SignedInfo>
                <ds:SignatureValue>aUDFmiG71</ds:SignatureValue>
            </ds:Signature>
        </B>
    </A>
    <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"Id="_6b02fb8a-30df-42c6-ba25-76eba02c8214">
        <ds:SignedInfo>
            <ds:CanonicalizationMethod
                Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
            <ds:SignatureMethod
                Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
            <ds:Reference URI="#IDforA">
                ...
            </ds:Reference>
        </ds:SignedInfo>
        <ds:SignatureValue>q3tvRoGgc8cMUqUSzP6C21zb7tt04riPnDuk=</ds:SignatureValue>
    </ds:Signature>
<root>

The example shows that you can sign several elements and that for each element a signature is created as sibling. The elements to be signed must have an attribute of type ID. The ID type of the attribute must be defined in the XML schema (see option schemaResourceUri). You specify a list of XPATH expressions pointing to attributes of type ID (see option xpathsToIdAttributes). These attributes determine the elements to be signed. The elements are signed by the same key given by the keyAccessor bean. Elements with higher (i.e. deeper) hierarchy level are signed first. In the example, the element C is signed before the element A.

Java DSL Example

from("direct:detached")
  .to("xmlsecurity:sign://detached?keyAccessor=#keyAccessorBeant&xpathsToIdAttributes=#xpathsToIdAttributesBean&schemaResourceUri=Test.xsd")
  .to("xmlsecurity:verify://detached?keySelector=#keySelectorBean&schemaResourceUri=org/apache/camel/component/xmlsecurity/Test.xsd")
  .to("mock:result");

Spring Example

   
<bean id="xpathsToIdAttributesBean" class="java.util.ArrayList">
      <constructor-arg type="java.util.Collection">
          <list>
              <bean
                  class="org.apache.camel.component.xmlsecurity.api.XmlSignatureHelper"
                  factory-method="getXpathFilter">
                  <constructor-arg type="java.lang.String"
                      value="/ns:root/a/@ID" />
                  <constructor-arg>
                      <map key-type="java.lang.String" value-type="java.lang.String">
                          <entry key="ns" value="http://test" />
                      </map>
                  </constructor-arg>
              </bean>
          </list>
      </constructor-arg>
  </bean>
...
 <from uri="direct:detached" />
      <to
          uri="xmlsecurity:sign://detached?keyAccessor=#keyAccessorBean&amp;xpathsToIdAttributes=#xpathsToIdAttributesBean&amp;schemaResourceUri=Test.xsd" />
      <to
          uri="xmlsecurity:verify://detached?keySelector=#keySelectorBean&amp;schemaResourceUri=Test.xsd" />
      <to uri="mock:result" />

Available as of Camel 2.15.0 

XML Advanced Electronic Signatures (XAdES) defines extensions to XML Signature. This standard was defined by the European Telecommunication Standards Institute and allows you to create signatures which are compliant to the European Union Directive (1999/93/EC) on a Community framework for electronic signatures. XAdES defines different sets of signature properties which are called signature forms. We support the signature forms Basic Electronic Signature (XAdES-BES) and Explicit Policy Based Electronic Signature (XAdES-EPES) for the Signer Endpoint. The forms Electronic Signature with Validation Data XAdES-T and XAdES-C are not supported.

We support the following properties of the XAdES-EPES form ("?" denotes zero or one occurrence):

Supported XAdES-EPES Properties

<QualifyingProperties Target>
    <SignedProperties>
        <SignedSignatureProperties>
            (SigningTime)?
            (SigningCertificate)?
            (SignaturePolicyIdentifier)
            (SignatureProductionPlace)?
            (SignerRole)?
        </SignedSignatureProperties>
        <SignedDataObjectProperties>
            (DataObjectFormat)?
            (CommitmentTypeIndication)?
        </SignedDataObjectProperties>
    </SignedProperties>
</QualifyingProperties>

The properties of the XAdES-BES form are the same except that the SignaturePolicyIdentifier property is not part of XAdES-BES. 

You can configure the XAdES-BES/EPES properties via the bean org.apache.camel.component.xmlsecurity.api.XAdESSignatureProperties or org.apache.camel.component.xmlsecurity.api.DefaultXAdESSignatureProperties. XAdESSignatureProperties does support all properties mentioned above except the SigningCertificate property. To get the SigningCertificate property, you must overwrite either the method XAdESSignatureProperties.getSigningCertificate() or XAdESSignatureProperties.getSigningCertificateChain(). The class DefaultXAdESSignatureProperties overwrites the method getSigningCertificate() and allows you to specify the signing certificate via a keystore and alias. The following example shows all parameters you can specify. If you do not need certain parameters you can just omit them.

XAdES-BES/EPES Example in Java DSL

 Keystore keystore = ... // load a keystore
DefaultKeyAccessor accessor = new DefaultKeyAccessor();
accessor.setKeyStore(keystore);
accessor.setPassword("password");
accessor.setAlias("cert_alias"); // signer key alias
 
DefaultXAdESSignatureProperties props = new DefaultXAdESSignatureProperties();
props.setNamespace("http://uri.etsi.org/01903/v1.3.2#"); // sets the namespace for the XAdES elements; the namspace is related to the XAdES version, default value is "http://uri.etsi.org/01903/v1.3.2#", other possible values are "http://uri.etsi.org/01903/v1.1.1#" and "http://uri.etsi.org/01903/v1.2.2#"
props.setPrefix("etsi"); // sets the prefix for the XAdES elements, default value is "etsi"
 
// signing certificate
props.setKeystore(keystore));
props.setAlias("cert_alias"); // specify the alias of the signing certificate in the keystore = signer key alias
props.setDigestAlgorithmForSigningCertificate(DigestMethod.SHA256); // possible values for the algorithm are "http://www.w3.org/2000/09/xmldsig#sha1", "http://www.w3.org/2001/04/xmlenc#sha256", "http://www.w3.org/2001/04/xmldsig-more#sha384", "http://www.w3.org/2001/04/xmlenc#sha512", default value is "http://www.w3.org/2001/04/xmlenc#sha256"
props.setSigningCertificateURIs(Collections.singletonList("http://certuri"));
 
// signing time
props.setAddSigningTime(true);
 
// policy
props.setSignaturePolicy(XAdESSignatureProperties.SIG_POLICY_EXPLICIT_ID);
// also the values XAdESSignatureProperties.SIG_POLICY_NONE ("None"), and XAdESSignatureProperties.SIG_POLICY_IMPLIED ("Implied")are possible, default value is XAdESSignatureProperties.SIG_POLICY_EXPLICIT_ID ("ExplicitId")
// For "None" and "Implied" you must not specify any further policy parameters
props.setSigPolicyId("urn:oid:1.2.840.113549.1.9.16.6.1");
props.setSigPolicyIdQualifier("OIDAsURN"); //allowed values are empty string, "OIDAsURI", "OIDAsURN"; default value is empty string
props.setSigPolicyIdDescription("invoice version 3.1");
props.setSignaturePolicyDigestAlgorithm(DigestMethod.SHA256);// possible values for the algorithm are "http://www.w3.org/2000/09/xmldsig#sha1", http://www.w3.org/2001/04/xmlenc#sha256", "http://www.w3.org/2001/04/xmldsig-more#sha384", "http://www.w3.org/2001/04/xmlenc#sha512", default value is http://www.w3.org/2001/04/xmlenc#sha256"
props.setSignaturePolicyDigestValue("Ohixl6upD6av8N7pEvDABhEL6hM=");
// you can add  qualifiers for the signature policy either by specifying text or an XML fragment with the root element "SigPolicyQualifier"
props.setSigPolicyQualifiers(Arrays
    .asList(new String[] {
        "<SigPolicyQualifier xmlns=\"http://uri.etsi.org/01903/v1.3.2#\"><SPURI>http://test.com/sig.policy.pdf</SPURI><SPUserNotice><ExplicitText>display text</ExplicitText>"
            + "</SPUserNotice></SigPolicyQualifier>", "category B" }));
props.setSigPolicyIdDocumentationReferences(Arrays.asList(new String[] {"http://test.com/policy.doc.ref1.txt",
    "http://test.com/policy.doc.ref2.txt" }));
 
// production place
props.setSignatureProductionPlaceCity("Munich");
props.setSignatureProductionPlaceCountryName("Germany");
props.setSignatureProductionPlacePostalCode("80331");
props.setSignatureProductionPlaceStateOrProvince("Bavaria");
 
//role
// you can add claimed roles either by specifying text or an XML fragment with the root element "ClaimedRole"
props.setSignerClaimedRoles(Arrays.asList(new String[] {"test",
    "<a:ClaimedRole xmlns:a=\"http://uri.etsi.org/01903/v1.3.2#\"><TestRole>TestRole</TestRole></a:ClaimedRole>" }));
props.setSignerCertifiedRoles(Collections.singletonList(new XAdESEncapsulatedPKIData("Ahixl6upD6av8N7pEvDABhEL6hM=",
    "http://uri.etsi.org/01903/v1.2.2#DER", "IdCertifiedRole")));
 
// data object format
props.setDataObjectFormatDescription("invoice");
props.setDataObjectFormatMimeType("text/xml");
props.setDataObjectFormatIdentifier("urn:oid:1.2.840.113549.1.9.16.6.2");
props.setDataObjectFormatIdentifierQualifier("OIDAsURN"); //allowed values are empty string, "OIDAsURI", "OIDAsURN"; default value is empty string
props.setDataObjectFormatIdentifierDescription("identifier desc");
props.setDataObjectFormatIdentifierDocumentationReferences(Arrays.asList(new String[] {
    "http://test.com/dataobject.format.doc.ref1.txt", "http://test.com/dataobject.format.doc.ref2.txt" }));
 
//commitment
props.setCommitmentTypeId("urn:oid:1.2.840.113549.1.9.16.6.4");
props.setCommitmentTypeIdQualifier("OIDAsURN"); //allowed values are empty string, "OIDAsURI", "OIDAsURN"; default value is empty string
props.setCommitmentTypeIdDescription("description for commitment type ID");
props.setCommitmentTypeIdDocumentationReferences(Arrays.asList(new String[] {"http://test.com/commitment.ref1.txt",
    "http://test.com/commitment.ref2.txt" }));
// you can specify a commitment type qualifier either by simple text or an XML fragment with root element "CommitmentTypeQualifier"
props.setCommitmentTypeQualifiers(Arrays.asList(new String[] {"commitment qualifier",
    "<c:CommitmentTypeQualifier xmlns:c=\"http://uri.etsi.org/01903/v1.3.2#\"><C>c</C></c:CommitmentTypeQualifier>" }));
 
beanRegistry.bind("xmlSignatureProperties",props);
beanRegistry.bind("keyAccessorDefault",keyAccessor);
 
// you must reference the properties bean in the "xmlsecurity" URI
from("direct:xades").to("xmlsecurity:sign://xades?keyAccessor=#keyAccessorDefault&properties=#xmlSignatureProperties")
             .to("mock:result");

XAdES-BES/EPES Example in Spring XML

...
<from uri="direct:xades" />
    <to
        uri="xmlsecurity:sign://xades?keyAccessor=#accessorRsa&amp;properties=#xadesProperties" />
    <to uri="mock:result" />
...
<bean id="xadesProperties"
    class="org.apache.camel.component.xmlsecurity.api.XAdESSignatureProperties">
    <!-- For more properties see the the previous Java DSL example. 
         If you want to have a signing certificate then use the bean class DefaultXAdESSignatureProperties (see the previous Java DSL example). -->
    <property name="signaturePolicy" value="ExplicitId" />
    <property name="sigPolicyId" value="http://www.test.com/policy.pdf" />
    <property name="sigPolicyIdDescription" value="factura" />
    <property name="signaturePolicyDigestAlgorithm" value="http://www.w3.org/2000/09/xmldsig#sha1" />
    <property name="signaturePolicyDigestValue" value="Ohixl6upD6av8N7pEvDABhEL1hM=" />
    <property name="signerClaimedRoles" ref="signerClaimedRoles_XMLSigner" />
    <property name="dataObjectFormatDescription" value="Factura electrónica" />
    <property name="dataObjectFormatMimeType" value="text/xml" />
</bean>
<bean class="java.util.ArrayList" id="signerClaimedRoles_XMLSigner">
    <constructor-arg>
        <list>
            <value>Emisor</value>
            <value>&lt;ClaimedRole
                xmlns=&quot;http://uri.etsi.org/01903/v1.3.2#&quot;&gt;&lt;test
                xmlns=&quot;http://test.com/&quot;&gt;test&lt;/test&gt;&lt;/ClaimedRole&gt;</value>
        </list>
    </constructor-arg>
</bean>