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Retrofit Adoption

If you need to convert legacy documentation to OSCAL, follow this path.

If you are approaching OSCAL to intially create your system security plan and do not have legacy documentaiton to convert, follow the New Adoption path.

Organizations with existing Word and Excel based authorization packages need to first migrate their content to OSCAL with only the minimum necessary refactoring.

OSCAL is designed to meet you where you are. It allows conversion of content as-is. Once converted, it allows you to migrate over time from that initial convestion to OSCAL's more data-normalized approach.

As with any technology project, OSCAL adoption should start with the minimum viable product (MVP) and evolve to more comprehensive use cases.

SSP Retrofit Adoption Overview

The OSCAL Foundation recommends the following addoption path for FedRAMP SSP migration.

SSP_Adoption_Path.png

To facilitate conversion of legacy Word content, OSCAL allows legacy control responses to be associated with the "this-system" component. CSPs can migrate slowly over time to the OSCAL-preferred, component-specific responses.

See details below.

SSP Adoption Path

Minimum Viable Product (MVP)

  • Minimum Front-Matter and OSCAL-required Content.

    • metadata includes:
      • title, published, last-modified, version, oscal-version
      • roles: CSP, ISSO, others as cited in controls
      • parties: the CSP
      • responsible-party: exactly one, linking the CSP party to the CSP role
    • system-characteristics includes:
      • system-id, system-name, system-name-short, description
      • cloud-service-model prop and cloud-deployment-model prop
      • security-sensitivity-level (fips-199-high, fips-199-moderate, fips-199-low)
      • system-information: exactly one entry with Appendix K pasted into the description
      • status: Required field. Use as-is
      • authorization-boundary: description and links entry identifying the external attachment.
      • network-architecture: description and links entry identifying the external attachment.
      • data-flow: description and links entry identifying the external attachment.
    • system-implementation includes:
      • users: Required by OSCAL, but no longer required by FedRAMP.
        • Single authorized-privilegesentry with emptytitleandfunction-performed` set to "none"
      • this-system components entry

  • Convert controls without modification, with all response statements in the "this-system" component.

    • control-implementation
      • implemented-requirement (AC-1, AC-2, etc.)
        • set-parameters: set parameters as needed
        • statement (part a, part b, etc.
          • by-component ("this system")
            • description: Content directly from legacy Word SSP (part a, part b, etc.)
            • implementation-status
            • responsible-roles: One entry per role. Use role-id. Must match metadata/roles/id.

  • Flat Inventory, converted directly from spreadsheet. No corrisponding components.

    • system-implementation:
      • inventory-items: All inventory converted from Excel spreadsheet

Intermediate

  • Required attachments

    • Add direct links from the appropriate controls to identify relevant attachments

  • Required SSP roles

    • metadata/roles The roles required by SSP (System owner, ISSO, AO, etc.)
    • metada/parties: the people, teams and organizations responsible for the above roles
    • metadata/responsible-parties: links the above roles and parties

  • Information types

    • system-characteristics/system-information/information-types
      • a single entry for each row in appendix K.

  • leveraged authorizations

    • system-implementation/leveraged-authorizations:
      • one entry for leveraged authorization
      • corrisponding metadata/parties entry for each
      • corrisponding system-implementation/components for each.

  • Separation of Duties Matrix

    • system-implementation/users
      • one entry per row in Table 11.1
      • ./authorized-privilege/functions-performed: SSP Table 11.1 Duty Description (just one entry in the array)
      • ./authorized-privilege/title: Required by OSCAL, not by FedRAMP. Recommend duplicating the functions-performed content.
      • role-ids: links metadata/roles to functions-performed

  • Customer Responsibility and Inheritance:

    • Move customer responsibility statements to //by-components/export/responsibilities

Advanced

  • Normalize Inventory: Transition flat inventory to component-based inventory.

    • Use components to the greatest degree practical
    • inventory-items become implemented instances of components

  • external systems and services

    • system-implementation/components entries for each

  • Transition to resources

    • Where practical, links entries use URI fragments to reference resources instead of direct links.

  • Components for Required Documents

    • policy components entries for each required policy
    • process-procedure components entries for each required process
    • plan components entries for each required plan
    • _useradd components for policies, processes, plans and other documents

Ideal

  • Services, Ports and Protocols

  • Cryptographic Modules (App Q table)

  • Migrateto component-based control responses

    • Add by-components entries to implemented-requirements for each relevant component
    • Add/move component-specific control responses to their associated by-components response.
    • Migrate slowly over time.
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