/usr/include/xmltooling/security/ is in libxmltooling-dev 1.5.6-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/xmltooling/security/AbstractPKIXTrustEngine.h
/usr/include/xmltooling/security/BasicX509Credential.h
/usr/include/xmltooling/security/ChainingTrustEngine.h
/usr/include/xmltooling/security/Credential.h
/usr/include/xmltooling/security/CredentialContext.h
/usr/include/xmltooling/security/CredentialCriteria.h
/usr/include/xmltooling/security/CredentialResolver.h
/usr/include/xmltooling/security/KeyInfoCredentialContext.h
/usr/include/xmltooling/security/KeyInfoResolver.h
/usr/include/xmltooling/security/OpenSSLCredential.h
/usr/include/xmltooling/security/OpenSSLCryptoX509CRL.h
/usr/include/xmltooling/security/OpenSSLPathValidator.h
/usr/include/xmltooling/security/OpenSSLTrustEngine.h
/usr/include/xmltooling/security/PKIXPathValidatorParams.h
/usr/include/xmltooling/security/PathValidator.h
/usr/include/xmltooling/security/SecurityHelper.h
/usr/include/xmltooling/security/SignatureTrustEngine.h
/usr/include/xmltooling/security/TrustEngine.h
/usr/include/xmltooling/security/X509Credential.h
/usr/include/xmltooling/security/X509TrustEngine.h
/usr/include/xmltooling/security/XSECCryptoX509CRL.h