Implement OOXML Relationships Transform Algorithm

Reference: ISO/IEC 29500-2:2012(E), section 13.2.4.24

Author: Miklos Vajna

include/xmlsec/strings.h

@@ -496,6 +496,18 @@ XMLSEC_EXPORT_VAR const xmlChar xmlSecXPath2FilterUnion[];
 XMLSEC_EXPORT_VAR const xmlChar xmlSecNameXPointer[];
 XMLSEC_EXPORT_VAR const xmlChar xmlSecNodeXPointer[];
 
+/*************************************************************************
+ *
+ * RelationshipTransform strings
+ *
+ ************************************************************************/
+XMLSEC_EXPORT_VAR const xmlChar xmlSecNameRelationship[];
+XMLSEC_EXPORT_VAR const xmlChar xmlSecHrefRelationship[];
+XMLSEC_EXPORT_VAR const xmlChar xmlSecNodeRelationship[];
+XMLSEC_EXPORT_VAR const xmlChar xmlSecNodeRelationshipReference[];
+XMLSEC_EXPORT_VAR const xmlChar xmlSecRelationshipsNs[];
+XMLSEC_EXPORT_VAR const xmlChar xmlSecRelationshipReferenceNs[];
+
 /*************************************************************************
  *
  * Xslt strings

include/xmlsec/transforms.h

@@ -949,6 +949,15 @@ XMLSEC_EXPORT int               xmlSecTransformXPointerSetExpr          (xmlSecT
                                                                          const xmlChar* expr,
                                                                          xmlSecNodeSetType nodeSetType,
                                                                          xmlNodePtr hereNode);
+/**
+ * xmlSecTransformRelationshipId:
+ *
+ * The Relationship transform klass.
+ */
+#define xmlSecTransformRelationshipId \
+        xmlSecTransformRelationshipGetKlass()
+XMLSEC_EXPORT xmlSecTransformId xmlSecTransformRelationshipGetKlass     (void);
+
 #ifndef XMLSEC_NO_XSLT
 #include <libxslt/security.h>
 

src/strings.c

@@ -490,6 +490,18 @@ const xmlChar xmlSecXPath2FilterUnion[]         = "union";
 const xmlChar xmlSecNameXPointer[]              = "xpointer";
 const xmlChar xmlSecNodeXPointer[]              = "XPointer";
 
+/*************************************************************************
+ *
+ * Relationship strings
+ *
+ ************************************************************************/
+const xmlChar xmlSecNameRelationship[]          = "relationship";
+const xmlChar xmlSecHrefRelationship[]          = "http://schemas.openxmlformats.org/package/2006/RelationshipTransform";
+const xmlChar xmlSecNodeRelationship[]          = "Relationship";
+const xmlChar xmlSecNodeRelationshipReference[] = "RelationshipReference";
+const xmlChar xmlSecRelationshipsNs[]           = "http://schemas.openxmlformats.org/package/2006/relationships";
+const xmlChar xmlSecRelationshipReferenceNs[]   = "http://schemas.openxmlformats.org/package/2006/digital-signature";
+
 /*************************************************************************
  *
  * Xslt strings

src/transforms.c

@@ -281,6 +281,16 @@ xmlSecTransformIdsRegisterDefault(void) {
         return(-1);
     }
 
+    if(xmlSecTransformIdsRegister(xmlSecTransformRelationshipId) < 0) {
+        xmlSecError(XMLSEC_ERRORS_HERE,
+                    NULL,
+                    "xmlSecTransformIdsRegister",
+                    XMLSEC_ERRORS_R_XMLSEC_FAILED,
+                    "name=%s",
+                    xmlSecErrorsSafeString(xmlSecTransformKlassGetName(xmlSecTransformRelationshipId)));
+        return(-1);
+    }
+
 #ifndef XMLSEC_NO_XSLT
     if(xmlSecTransformIdsRegister(xmlSecTransformXsltId) < 0) {
         xmlSecError(XMLSEC_ERRORS_HERE,