Digital Signatures and Digital Signatures and e-Identity.e-Identity.

Getting the best out of DSS / Getting the best out of DSS / DSS-X services. DSS-X services.

www.oasis-open.org

Andreas Kuehne – DSS-X memberAndreas Kuehne – DSS-X member

'Protocols for central services providing signature generation AND verification'Avoid problems of deployment of infrastructure

required to support individual generationAll the complexity of verification implemented and

deployed once at the server.Reduces overhead of key management: the central

server takes care of the required tasks on certs status in both generation and verification.

All the details of the policy for the signatures centralized.

May keep logs of the verification processes and results.

Coarse Orientation:

DSS is an OASIS Standard !Official standard since 2008

Many profiles part of DSSFormat ( e.g. XAdES, Code Signing )Scope ( EPM, German Sig. Law )Transport ( Async )

Requirement for agreed IPR mode caused termination of DSS

What's already there:

DSS-X TCFounded in 2008Many DSS members joined

Maintenance of core spec

New profile areasSpecializing profiles Extending existing functionalities Into the unknown

What's new :

Specializing existing profilesJ2SE code signing

Extending existing functionalitiesebXML

Into the unknownEncryption and decryption profileVisible signatures Individual Reports on Signatures… to do …Signature & Service PolicySigned Verification Responses

Complete Profile List:

Get a more detailed knowledge about some selected profiles that may be useful for e-identity applications :

Verification reports

ebXML

J2SE code signing

Detailed Look :

Provides support for multiple signatures Comprehensive signature verification reports for :

XML-Signatures [RFC 3275], [ETSI 101903] CMS-Signatures [RFC 3852], [ETSI 101733] Time Stamps [RFC 3161], [OASIS DSS] Public-Key Certificates [RFC 5280] Certificate Revocation Lists [RFC 5280] Attribute Certificates [RFC 3281] OCSP-Responses [RFC 2560] Evidence Records [RFC 4998] arbitrary other structures (in additional profiles)

Comprehensive Signature Verification Report Profile

For each verified signature an individual report is issued, which includes :Details on cryptographic verification of the signatureFor each certificate in the certification path:

Details on the cryptographic verification Details on their status (this may include references or values

of CRLs and OCSP responses for instance). Details on certificate in their certification paths

Details on the signed and unsigned properties present within the signature.

Comprehensive Signature Verification Report Profile

If time-stamps are present within the signature,for each one, the report includes:Details on the cryptographic verification of the time-

stamp itself.For each certificate in the certification path of time-

stamp certificate : Details on the cryptographic verification Details on their status. Details on certificate in their certification paths

Details of the checks performed against the Trusted Status Lists ( providing information of the status of the Trusted

Services Providers issuing PKI related material ).

Comprehensive Signature Verification Report Profile

DetailedSignatureReport

Properties

FormatOK

Details on all the cer-tificates in the path(in next slide)

VerifyManifestResultst

e.g. time-stamps

SignatureOK

CertificatePathValidity

CertificateIdentifierPathValiditySummary PathValidityDetail

PathValidityDetail

TSLValidity CertificateValidity

Details on the status of this certificate (including CRL, OCSP responses) in next slide

Subject

CertificateIdentifier

ChainingOK

ValidityPeriodOK

ExtensionsOK

CertificateValue

CertificateContent

SignatureOK

CertificateStatus

Details XML encodedof contents of thiscertificate.

CertificateStatus

RevocationInfo

CertStatusOK

Details certificationpath for the CRL itself

RevocationEvidence

CRLValidity

CRLReference

RevocationDate

RevocationReason

OCSPValidity

OCSPReference

Other

Details certificationpath for the OCSPResponse itself

Optional Input / Output

Structure of IndividualReport

Individual Structures

ebXML Profile ebXML Messaging (ebMS) is an advanced OASIS

Standard messaging protocol: Synchronous or asynchronous SOAP-based messaging Reliable and secure messaging Standard business metadata in document header OASIS Standards version 2.0 (2002), version 3.0 (2007)

The DSS-X ebXML profile defines a transport protocol binding to ebMS

Complements the transport bindings defined in DSS Leverages the advanced features of ebMS

The DSS-X ebXML profile supports: Communities that want to leverage their existing e-business or

e-government ebMS infrastructures for DSS services Scenarios such as cross-enterprise document workflows;

document archival and retrieval; scanned document handling

ebXML usage statement A government agency in the Netherlands uses the DSS

ebXML profile inproduction to interact with a remote DSS provider.

The service provider provides remote PDF certification of scanned documents.

The agency and the provider are currently exchanging several hundreds DSS ebMS messages per day, each containing a medium to large-size (tens of MBs) PDF document.

Code Signing details

Code signing is crucial for building a trustworthy system of software artifacts.

Code signing is supported by many development tools ( like 'ant' ) out-of-the-box !

Secret keys reside in the file system. Lax key management in development department.

CS profile advantages Centralized signing pays off in the usual way :

Control about secret keys Easy certificate mangement Controlling who signs Tracking what / when / by whom was signed

Access can be managed on per-user basis.

Even automatic build environments supported.

J2SE profile details J2SE defines a special standard on top of PKCS7. New profile applicable for Applets and WebStart

applications. DSS already included a profile for Java Micro Edition.

Usage statement : Trustable uses the CS profile to build a verification

applet. Ant task is available under GPL as well as the DSS

implementation.

Public review ebXMLVisible SignatureSignature PolicyIndividual Verification ReportOther ..

Conformance and InterOp tests ??? can we agree on an estimated date ??

Further process ?? can we guess a date for ‘going to standard’ ??

Standardization forecast