Microsoft Windows 10 Windows Hello Step-Up Sign Challenge

arazzo: 1.0.1
info:
  title: Microsoft Windows 10 Windows Hello Step-Up Sign Challenge
  summary: Verify the user with biometrics or PIN, open their key credential, and sign a server challenge for step-up authentication.
  description: >-
    A step-up authentication flow built on the Windows.Security.Credentials
    namespace. Before a sensitive operation, the workflow prompts the user to
    verify their identity with Windows Hello via UserConsentVerifier, branches on
    the verification result, opens the existing key credential for the account,
    and signs a server-supplied challenge with the credential's private key so
    the server can verify the user. Every step inlines its request and documents
    the status it keys on.
  version: 1.0.0
sourceDescriptions:
- name: helloApi
  url: ../openapi/microsoft-windows-10-hello-openapi.yml
  type: openapi
workflows:
- workflowId: stepup-sign-challenge
  summary: Verify the user then sign a challenge with their Windows Hello credential.
  description: >-
    Prompts the user for Windows Hello verification, and on a verified result
    opens the account credential and signs the supplied challenge buffer.
  inputs:
    type: object
    required:
    - accountId
    - challenge
    properties:
      accountId:
        type: string
        description: Account identifier whose credential signs the challenge.
      challenge:
        type: string
        description: Base64-encoded challenge buffer to sign.
      message:
        type: string
        description: Message shown to the user in the verification prompt.
        default: Confirm your identity to continue.
  steps:
  - stepId: verifyUser
    description: >-
      Prompt the user to verify their identity with Windows Hello biometrics or
      PIN, and only proceed when the result is Verified.
    operationId: verifyUserConsent
    requestBody:
      contentType: application/json
      payload:
        message: $inputs.message
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.result == "Verified"
      type: jsonpath
    outputs:
      result: $response.body#/result
    onSuccess:
    - name: verified
      type: goto
      stepId: openCredential
      criteria:
      - context: $response.body
        condition: $.result == "Verified"
        type: jsonpath
  - stepId: openCredential
    description: >-
      Open the existing Windows Hello key credential for the account so it can be
      used for signing.
    operationId: openKeyCredential
    parameters:
    - name: accountId
      in: path
      value: $inputs.accountId
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.status == "Success"
      type: jsonpath
    outputs:
      accountId: $response.body#/accountId
      status: $response.body#/status
  - stepId: signChallenge
    description: >-
      Sign the supplied challenge buffer with the credential's private key and
      capture the signature for server-side verification.
    operationId: signWithCredential
    requestBody:
      contentType: application/json
      payload:
        accountId: $steps.openCredential.outputs.accountId
        challenge: $inputs.challenge
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.status == "Success"
      type: jsonpath
    outputs:
      status: $response.body#/status
      signature: $response.body#/signature
  outputs:
    verificationResult: $steps.verifyUser.outputs.result
    accountId: $steps.openCredential.outputs.accountId
    signature: $steps.signChallenge.outputs.signature