Amazon KMS Envelope Encrypt and Decrypt

arazzo: 1.0.1
info:
  title: Amazon KMS Envelope Encrypt and Decrypt
  summary: Generate a data key, then round-trip ciphertext through encrypt and decrypt.
  description: >-
    Demonstrates the canonical KMS envelope-encryption pattern. The workflow
    generates a symmetric data key under a KMS key, encrypts a small plaintext
    payload directly with the KMS key, and then decrypts the resulting ciphertext
    to prove the round trip succeeds. The data key, ciphertext blob, and plaintext
    are chained between steps. Each step spells out its request inline, including
    the AWS JSON protocol X-Amz-Target header, so the flow can be read and
    executed without opening the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: kmsApi
  url: ../openapi/amazon-kms-openapi.yml
  type: openapi
workflows:
- workflowId: envelope-encrypt-decrypt
  summary: Generate a data key, encrypt plaintext, then decrypt the ciphertext.
  description: >-
    Generates a data key for client-side use, encrypts a plaintext payload with
    the KMS key, and decrypts the returned ciphertext to verify the full
    envelope cycle.
  inputs:
    type: object
    required:
    - KeyId
    - Plaintext
    properties:
      KeyId:
        type: string
        description: Identifies the KMS key used for the cryptographic operations.
      Plaintext:
        type: string
        description: Base64-encoded plaintext (up to 4,096 bytes) to encrypt.
      KeySpec:
        type: string
        description: The length of the data key to generate (e.g. AES_256).
  steps:
  - stepId: generateDataKey
    description: >-
      Generate a unique symmetric data key under the KMS key for client-side
      encryption, returning both the plaintext and encrypted forms.
    operationId: GenerateDataKey
    parameters:
    - name: KeyId
      in: path
      value: $inputs.KeyId
    - name: X-Amz-Target
      in: header
      value: TrentService.GenerateDataKey
    requestBody:
      contentType: application/x-amz-json-1.1
      payload:
        KeyId: $inputs.KeyId
        KeySpec: $inputs.KeySpec
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      dataKeyCiphertext: $response.body#/CiphertextBlob
      dataKeyPlaintext: $response.body#/Plaintext
  - stepId: encrypt
    description: >-
      Encrypt the supplied plaintext payload directly with the KMS key and
      capture the resulting ciphertext blob.
    operationId: Encrypt
    parameters:
    - name: KeyId
      in: path
      value: $inputs.KeyId
    - name: X-Amz-Target
      in: header
      value: TrentService.Encrypt
    requestBody:
      contentType: application/x-amz-json-1.1
      payload:
        KeyId: $inputs.KeyId
        Plaintext: $inputs.Plaintext
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      ciphertextBlob: $response.body#/CiphertextBlob
  - stepId: decrypt
    description: >-
      Decrypt the ciphertext produced by the encrypt step to verify the round
      trip returns the original plaintext.
    operationId: Decrypt
    parameters:
    - name: X-Amz-Target
      in: header
      value: TrentService.Decrypt
    requestBody:
      contentType: application/x-amz-json-1.1
      payload:
        KeyId: $inputs.KeyId
        CiphertextBlob: $steps.encrypt.outputs.ciphertextBlob
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      decryptedPlaintext: $response.body#/Plaintext
  outputs:
    dataKeyCiphertext: $steps.generateDataKey.outputs.dataKeyCiphertext
    ciphertextBlob: $steps.encrypt.outputs.ciphertextBlob
    decryptedPlaintext: $steps.decrypt.outputs.decryptedPlaintext