Module: Pdfrb::Conformance::Ltv

Defined in:

lib/pdfrb/conformance/ltv.rb

Overview

Long-Term Validation (LTV) per ETSI EN 319 102-1 Annex B. LTV preserves the validity of a signature beyond the validity period of the signer's certificate by archiving revocation data and timestamping the archive over time.

LTV requires:

* At least one signature with /ByteRange and /Contents.
* /DSS dictionary on Catalog with /Certs, /CRLs, /OCSPs as
applicable.
* For archival (LTA): a /DocumentTimeStamp on the catalog.

Constant Summary

RULESET =

RuleSet.new("LTV").tap do |rs|
  rs.register(Rule.new(
                id: "ltv-1",
                description: "/DSS dictionary required for LTV",
                severity: :error,
                spec_clause: "ETSI EN 319 102-1 B.5",
                check: ->(doc) {
                  next nil if doc.catalog[:DSS]

                  Violation.new(
                    rule_id: "ltv-1",
                    message: "LTV requires /DSS dictionary on Catalog",
                    object: "Catalog/DSS",
                    severity: :error,
                    spec_clause: "ETSI EN 319 102-1 B.5"
                  )
                }
              ))

  rs.register(Rule.new(
                id: "ltv-2",
                description: "/DSS must contain validation material",
                severity: :warning,
                spec_clause: "ETSI EN 319 102-1 B.5",
                check: ->(doc) {
                  dss = doc.catalog[:DSS]
                  dss = doc.object(dss) if dss.is_a?(Pdfrb::Model::Reference)
                  next nil unless dss

                  has_material = dss[:Certs] || dss[:CRLs] || dss[:OCSPs] ||
                                 dss[:VRI]
                  next nil if has_material

                  Violation.new(
                    rule_id: "ltv-2",
                    message: "/DSS is empty (no /Certs, /CRLs, /OCSPs, or /VRI)",
                    object: "Catalog/DSS",
                    severity: :warning,
                    spec_clause: "ETSI EN 319 102-1 B.5"
                  )
                }
              ))

  rs.register(Rule.new(
                id: "ltv-3",
                description: "At least one signature should be present",
                severity: :warning,
                spec_clause: "ETSI EN 319 102-1 B.4",
                check: ->(doc) {
                  fields = Pdfrb::Conformance::Pades.signature_fields(doc)
                  next nil if fields.any?

                  Violation.new(
                    rule_id: "ltv-3",
                    message: "LTV document has no signatures to validate",
                    object: "AcroForm/Fields",
                    severity: :warning,
                    spec_clause: "ETSI EN 319 102-1 B.4"
                  )
                }
              ))

  rs.register(Rule.new(
                id: "ltv-4",
                description: "Document Time Stamp for archival (LTA)",
                severity: :warning,
                spec_clause: "ETSI EN 319 102-1 B.6",
                check: ->(doc) {
                  fields = Pdfrb::Conformance::Pades.signature_fields(doc)
                  has_archival = fields.any? do |field|
                    v = field[:V]
                    v_obj = v.is_a?(Pdfrb::Model::Reference) ? doc.object(v) : v
                    v_obj && v_obj[:Type]&.to_sym == :DocTimeStamp
                  end
                  next nil if has_archival

                  Violation.new(
                    rule_id: "ltv-4",
                    message: "Long-Term Archival (LTA) recommends a Document Time Stamp",
                    object: "AcroForm/Fields",
                    severity: :warning,
                    spec_clause: "ETSI EN 319 102-1 B.6"
                  )
                }
              ))
end

Class Method Summary

• .validate(document) ⇒ Object

Class Method Details

.validate(document) ⇒ Object

# File 'lib/pdfrb/conformance/ltv.rb', line 106

def validate(document)
  RULESET.validate(document)
end