https://issues.shibboleth.net/jira/browse/CPPXT-58
[shibboleth/cpp-xmltooling.git] / xmltooling / util / ReloadableXMLFile.cpp
index 83a4293..e51d0ee 100644 (file)
 
 #include "internal.h"
 #include "io/HTTPResponse.h"
+#ifndef XMLTOOLING_LITE
+# include "security/Credential.h"
+# include "security/CredentialCriteria.h"
+# include "security/CredentialResolver.h"
+# include "security/SignatureTrustEngine.h"
+# include "signature/Signature.h"
+# include "signature/SignatureValidator.h"
+#endif
 #include "util/NDC.h"
 #include "util/PathResolver.h"
 #include "util/ReloadableXMLFile.h"
@@ -35,6 +43,7 @@
 # include <log4cpp/NDC.hh>
 #endif
 
+#include <memory>
 #include <fstream>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <xercesc/framework/Wrapper4InputSource.hpp>
 #include <xercesc/util/XMLUniDefs.hpp>
 
+#ifndef XMLTOOLING_LITE
+# include <xsec/dsig/DSIGReference.hpp>
+# include <xsec/dsig/DSIGTransformList.hpp>
+using namespace xmlsignature;
+#endif
+
 using namespace xmltooling::logging;
 using namespace xmltooling;
 using namespace xercesc;
 using namespace std;
 
+#ifndef XMLTOOLING_LITE
+namespace {
+    class XMLTOOL_DLLLOCAL DummyCredentialResolver : public CredentialResolver
+    {
+    public:
+        DummyCredentialResolver() {}
+        ~DummyCredentialResolver() {}
+
+        Lockable* lock() {return this;}
+        void unlock() {}
+
+        const Credential* resolve(const CredentialCriteria* criteria=nullptr) const {return nullptr;}
+        vector<const Credential*>::size_type resolve(
+            vector<const Credential*>& results, const CredentialCriteria* criteria=nullptr
+            ) const {return 0;}
+    };
+};
+#endif
+
 static const XMLCh id[] =               UNICODE_LITERAL_2(i,d);
 static const XMLCh uri[] =              UNICODE_LITERAL_3(u,r,i);
 static const XMLCh url[] =              UNICODE_LITERAL_3(u,r,l);
@@ -59,40 +93,50 @@ static const XMLCh validate[] =         UNICODE_LITERAL_8(v,a,l,i,d,a,t,e);
 static const XMLCh reloadChanges[] =    UNICODE_LITERAL_13(r,e,l,o,a,d,C,h,a,n,g,e,s);
 static const XMLCh reloadInterval[] =   UNICODE_LITERAL_14(r,e,l,o,a,d,I,n,t,e,r,v,a,l);
 static const XMLCh backingFilePath[] =  UNICODE_LITERAL_15(b,a,c,k,i,n,g,F,i,l,e,P,a,t,h);
+static const XMLCh type[] =             UNICODE_LITERAL_4(t,y,p,e);
+static const XMLCh certificate[] =      UNICODE_LITERAL_11(c,e,r,t,i,f,i,c,a,t,e);
+static const XMLCh signerName[] =       UNICODE_LITERAL_10(s,i,g,n,e,r,N,a,m,e);
+static const XMLCh _TrustEngine[] =     UNICODE_LITERAL_11(T,r,u,s,t,E,n,g,i,n,e);
+static const XMLCh _CredentialResolver[] = UNICODE_LITERAL_18(C,r,e,d,e,n,t,i,a,l,R,e,s,o,l,v,e,r);
 
 
 ReloadableXMLFile::ReloadableXMLFile(const DOMElement* e, Category& log)
-    : m_root(e), m_local(true), m_validate(false), m_backupIndicator(true), m_filestamp(0), m_reloadInterval(0), m_lock(NULL), m_log(log),
-        m_shutdown(false), m_reload_wait(NULL), m_reload_thread(NULL)
+    : m_root(e), m_local(true), m_validate(false), m_backupIndicator(true), m_filestamp(0), m_reloadInterval(0), m_lock(nullptr), m_log(log),
+#ifndef XMLTOOLING_LITE
+        m_credResolver(nullptr), m_trust(nullptr),
+#endif
+        m_shutdown(false), m_reload_wait(nullptr), m_reload_thread(nullptr)
 {
 #ifdef _DEBUG
     NDC ndc("ReloadableXMLFile");
 #endif
 
     // Establish source of data...
-    const XMLCh* source=e->getAttributeNS(NULL,uri);
+    const XMLCh* source=e->getAttributeNS(nullptr,uri);
     if (!source || !*source) {
-        source=e->getAttributeNS(NULL,url);
+        source=e->getAttributeNS(nullptr,url);
         if (!source || !*source) {
-            source=e->getAttributeNS(NULL,path);
+            source=e->getAttributeNS(nullptr,path);
             if (!source || !*source) {
-                source=e->getAttributeNS(NULL,pathname);
+                source=e->getAttributeNS(nullptr,pathname);
                 if (!source || !*source) {
-                    source=e->getAttributeNS(NULL,file);
+                    source=e->getAttributeNS(nullptr,file);
                     if (!source || !*source) {
-                        source=e->getAttributeNS(NULL,filename);
+                        source=e->getAttributeNS(nullptr,filename);
                     }
                 }
             }
         }
-        else
+        else {
             m_local=false;
+        }
     }
-    else
+    else {
         m_local=false;
+    }
 
     if (source && *source) {
-        const XMLCh* flag=e->getAttributeNS(NULL,validate);
+        const XMLCh* flag=e->getAttributeNS(nullptr,validate);
         m_validate=(XMLString::equals(flag,xmlconstants::XML_TRUE) || XMLString::equals(flag,xmlconstants::XML_ONE));
 
         auto_ptr_char temp(source);
@@ -103,10 +147,42 @@ ReloadableXMLFile::ReloadableXMLFile(const DOMElement* e, Category& log)
             m_local=true;
         }
 
+#ifndef XMLTOOLING_LITE
+        // Check for signature bits.
+        if (e && e->hasAttributeNS(nullptr, certificate)) {
+            // Use a file-based credential resolver rooted here.
+            m_credResolver = XMLToolingConfig::getConfig().CredentialResolverManager.newPlugin(FILESYSTEM_CREDENTIAL_RESOLVER, e);
+        }
+        else {
+            const DOMElement* sub = e ? XMLHelper::getFirstChildElement(e, _CredentialResolver) : nullptr;
+            auto_ptr_char t(sub ? sub->getAttributeNS(nullptr, type) : nullptr);
+            if (t.get()) {
+                m_credResolver = XMLToolingConfig::getConfig().CredentialResolverManager.newPlugin(t.get(), sub);
+            }
+            else {
+                sub = e ? XMLHelper::getFirstChildElement(e, _TrustEngine) : nullptr;
+                auto_ptr_char t2(sub ? sub->getAttributeNS(nullptr, type) : nullptr);
+                if (t2.get()) {
+                    TrustEngine* trust = XMLToolingConfig::getConfig().TrustEngineManager.newPlugin(t2.get(), sub);
+                    if (!(m_trust = dynamic_cast<SignatureTrustEngine*>(trust))) {
+                        delete trust;
+                        throw XMLToolingException("TrustEngine-based ReloadableXMLFile requires a SignatureTrustEngine plugin.");
+                    }
+
+                    flag = e->getAttributeNS(nullptr, signerName);
+                    if (flag && *flag) {
+                        auto_ptr_char sn(flag);
+                        m_signerName = sn.get();
+                    }
+                }
+            }
+        }
+#endif
+
         if (m_local) {
             XMLToolingConfig::getConfig().getPathResolver()->resolve(m_source, PathResolver::XMLTOOLING_CFG_FILE);
 
-            flag=e->getAttributeNS(NULL,reloadChanges);
+            flag=e->getAttributeNS(nullptr,reloadChanges);
             if (!XMLString::equals(flag,xmlconstants::XML_FALSE) && !XMLString::equals(flag,xmlconstants::XML_ZERO)) {
 #ifdef WIN32
                 struct _stat stat_buf;
@@ -124,14 +200,14 @@ ReloadableXMLFile::ReloadableXMLFile(const DOMElement* e, Category& log)
         }
         else {
             log.debug("using remote resource (%s)", m_source.c_str());
-            source = e->getAttributeNS(NULL,backingFilePath);
+            source = e->getAttributeNS(nullptr,backingFilePath);
             if (source && *source) {
                 auto_ptr_char temp2(source);
                 m_backing=temp2.get();
                 XMLToolingConfig::getConfig().getPathResolver()->resolve(m_backing, PathResolver::XMLTOOLING_RUN_FILE);
                 log.debug("backup remote resource to (%s)", m_backing.c_str());
             }
-            source = e->getAttributeNS(NULL,reloadInterval);
+            source = e->getAttributeNS(nullptr,reloadInterval);
             if (source && *source) {
                 m_reloadInterval = XMLString::parseInt(source);
                 if (m_reloadInterval > 0) {
@@ -139,7 +215,7 @@ ReloadableXMLFile::ReloadableXMLFile(const DOMElement* e, Category& log)
                     m_lock=RWLock::create();
                 }
             }
-            m_filestamp = time(NULL);   // assume it gets loaded initially
+            m_filestamp = time(nullptr);   // assume it gets loaded initially
         }
 
         if (m_lock) {
@@ -151,7 +227,7 @@ ReloadableXMLFile::ReloadableXMLFile(const DOMElement* e, Category& log)
         log.debug("no resource uri/path/name supplied, will load inline configuration");
     }
 
-    source = e->getAttributeNS(NULL, id);
+    source = e->getAttributeNS(nullptr, id);
     if (source && *source) {
         auto_ptr_char tempid(source);
         m_id = tempid.get();
@@ -170,11 +246,11 @@ void ReloadableXMLFile::shutdown()
         // Shut down the reload thread and let it know.
         m_shutdown = true;
         m_reload_wait->signal();
-        m_reload_thread->join(NULL);
+        m_reload_thread->join(nullptr);
         delete m_reload_thread;
         delete m_reload_wait;
-        m_reload_thread = NULL;
-        m_reload_wait = NULL;
+        m_reload_thread = nullptr;
+        m_reload_wait = nullptr;
     }
 }
 
@@ -241,7 +317,7 @@ void* ReloadableXMLFile::reload_fn(void* pv)
         logging::NDC::pop();
     }
 
-    return NULL;
+    return nullptr;
 }
 
 Lockable* ReloadableXMLFile::lock()
@@ -311,11 +387,11 @@ pair<bool,DOMElement*> ReloadableXMLFile::load(bool backup)
             else
                 m_log.debug("loading configuration from external resource...");
 
-            DOMDocument* doc=NULL;
+            DOMDocument* doc=nullptr;
             if (m_local || backup) {
                 auto_ptr_XMLCh widenit(backup ? m_backing.c_str() : m_source.c_str());
                 // Use library-wide lock for now, nothing else is using it anyway.
-                Locker locker(backup ? getBackupLock() : NULL);
+                Locker locker(backup ? getBackupLock() : nullptr);
                 LocalFileInputSource src(widenit.get());
                 Wrapper4InputSource dsrc(&src, false);
                 if (m_validate)
@@ -324,7 +400,7 @@ pair<bool,DOMElement*> ReloadableXMLFile::load(bool backup)
                     doc=XMLToolingConfig::getConfig().getParser().parse(dsrc);
             }
             else {
-                URLInputSource src(m_root, NULL, &m_cacheTag);
+                URLInputSource src(m_root, nullptr, &m_cacheTag);
                 Wrapper4InputSource dsrc(&src, false);
                 if (m_validate)
                     doc=XMLToolingConfig::getConfig().getValidatingParser().parse(dsrc);
@@ -346,6 +422,25 @@ pair<bool,DOMElement*> ReloadableXMLFile::load(bool backup)
             }
 
             m_log.infoStream() << "loaded XML resource (" << (backup ? m_backing : m_source) << ")" << logging::eol;
+#ifndef XMLTOOLING_LITE
+            if (m_credResolver || m_trust) {
+                m_log.debug("checking signature on XML resource");
+                try {
+                    DOMElement* sigel = XMLHelper::getFirstChildElement(doc->getDocumentElement(), xmlconstants::XMLSIG_NS, Signature::LOCAL_NAME);
+                    if (!sigel)
+                        throw XMLSecurityException("Signature validation required, but no signature found.");
+
+                    // Wrap and unmarshall the signature for the duration of the check.
+                    auto_ptr<Signature> sigobj(dynamic_cast<Signature*>(SignatureBuilder::buildOneFromElement(sigel)));    // don't bind to document
+                    validateSignature(*sigobj.get());
+                }
+                catch (exception&) {
+                    doc->release();
+                    throw;
+                }
+
+            }
+#endif
 
             if (!backup && !m_backing.empty()) {
                 // If the indicator is true, we're responsible for the backup.
@@ -387,6 +482,81 @@ pair<bool,DOMElement*> ReloadableXMLFile::load(bool backup)
     }
 }
 
+#ifndef XMLTOOLING_LITE
+
+void ReloadableXMLFile::validateSignature(Signature& sigObj) const
+{
+    DSIGSignature* sig=sigObj.getXMLSignature();
+    if (!sig)
+        throw XMLSecurityException("Signature does not exist yet.");
+
+    // Make sure the whole document was signed.
+    bool valid=false;
+    DSIGReferenceList* refs=sig->getReferenceList();
+    if (refs && refs->getSize()==1) {
+        DSIGReference* ref=refs->item(0);
+        if (ref) {
+            const XMLCh* URI=ref->getURI();
+            if (URI==nullptr || *URI==0) {
+                DSIGTransformList* tlist=ref->getTransforms();
+                if (tlist->getSize() <= 2) { 
+                    for (unsigned int i=0; tlist && i<tlist->getSize(); i++) {
+                        if (tlist->item(i)->getTransformType()==TRANSFORM_ENVELOPED_SIGNATURE)
+                            valid=true;
+                        else if (tlist->item(i)->getTransformType()!=TRANSFORM_EXC_C14N &&
+                                 tlist->item(i)->getTransformType()!=TRANSFORM_C14N &&
+                                 tlist->item(i)->getTransformType()!=TRANSFORM_C14N11) {
+                            valid=false;
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    
+    if (!valid)
+        throw XMLSecurityException("Invalid signature profile for signed configuration resource.");
+
+    // Set up criteria.
+    CredentialCriteria cc;
+    cc.setUsage(Credential::SIGNING_CREDENTIAL);
+    cc.setSignature(sigObj, CredentialCriteria::KEYINFO_EXTRACTION_KEY);
+    if (!m_signerName.empty())
+        cc.setPeerName(m_signerName.c_str());
+
+    if (m_credResolver) {
+        Locker locker(m_credResolver);
+        vector<const Credential*> creds;
+        if (m_credResolver->resolve(creds, &cc)) {
+            SignatureValidator sigValidator;
+            for (vector<const Credential*>::const_iterator i = creds.begin(); i != creds.end(); ++i) {
+                try {
+                    sigValidator.setCredential(*i);
+                    sigValidator.validate(&sigObj);
+                    return; // success!
+                }
+                catch (exception&) {
+                }
+            }
+            throw XMLSecurityException("Unable to verify signature with supplied key(s).");
+        }
+        else {
+            throw XMLSecurityException("CredentialResolver did not supply any candidate keys.");
+        }
+    }
+    else if (m_trust) {
+        DummyCredentialResolver dummy;
+        if (m_trust->validate(sigObj, dummy, &cc))
+            return;
+        throw XMLSecurityException("TrustEngine unable to verify signature.");
+    }
+
+    throw XMLSecurityException("Unable to verify signature.");
+}
+
+#endif
+
 pair<bool,DOMElement*> ReloadableXMLFile::load()
 {
     return load(false);