Smart DCC

DCC Boxed DUIS Signing Tool API

An open-source HTTP API published by Smart DCC Limited for signing and validating DUIS (DCC User Interface Specification) XML messages. Two operations — POST /sign adds an XML digital signature to a Base64-encoded unsigned DUIS request (with an optional preserveCounter flag), and POST /verify validates the signature on a DUIS response and strips it. The tool ships with the ZAZ1 test SMKI certificates used by DCC Boxed and also performs XSD validation. It runs locally as a self-hosted server; Smart DCC operates no public hosted instance.

Documentation GitHub OpenAPI

OpenAPI Specification

# Copyright (c) 2026 Smart DCC Limited
# Licensed under GPL-3.0

openapi: 3.0.3
info:
  title: DCC Boxed DUIS Signing Tool API
  description: HTTP API for signing and validating DUIS XML messages
  version: 1.0.0
  contact:
    name: Smart DCC Limited
  license:
    name: GPL-3.0
    url: https://www.gnu.org/licenses/gpl-3.0.html

servers:
  - url: http://localhost:8080
    description: Local development server

paths:
  /sign:
    post:
      summary: Sign a DUIS request
      description: Signs a DUIS XML message and returns the signed XML with digital signature
      operationId: signMessage
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - message
              properties:
                message:
                  type: string
                  format: byte
                  description: Base64-encoded unsigned DUIS XML message
                  example: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4...
                preserveCounter:
                  type: boolean
                  description: Optional. When true, preserves the original counter in the DUIS request. When false or omitted, overwrites with System.currentTimeMillis()
                  default: false
                  example: true
      responses:
        '200':
          description: Successfully signed message
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    format: byte
                    description: Base64-encoded signed DUIS XML message with digital signature
                    example: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4...
        '400':
          description: Bad request - invalid XML or signing error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '405':
          description: Method not allowed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'

  /verify:
    post:
      summary: Verify a DUIS response
      description: Validates a signed DUIS XML message and returns the unsigned XML
      operationId: verifyMessage
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - message
              properties:
                message:
                  type: string
                  format: byte
                  description: Base64-encoded signed DUIS XML message with digital signature
                  example: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4...
      responses:
        '200':
          description: Successfully verified message
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    format: byte
                    description: Base64-encoded validated DUIS XML message without digital signature
                    example: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4...
        '400':
          description: Bad request - invalid signature or validation error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '405':
          description: Method not allowed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'

components:
  schemas:
    Error:
      type: object
      properties:
        error:
          type: string
          description: Error message
        errorCode:
          type: string
          description: Exception class name

DCC Boxed DUIS Signing Tool API

Documentation

Specifications

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OpenAPI Specification