Update test to match new error message format

Co-authored-by: bdehamer <398027+bdehamer@users.noreply.github.com>

.eslintignore

@@ -1,4 +0,0 @@
-lib/
-dist/
-node_modules/
-coverage/

.github/linters/.eslintrc.yml

@@ -1,85 +0,0 @@
-env:
-  node: true
-  es6: true
-  jest: true
-
-globals:
-  Atomics: readonly
-  SharedArrayBuffer: readonly
-
-ignorePatterns:
-  - '!.*'
-  - '**/node_modules/.*'
-  - '**/dist/.*'
-  - '**/coverage/.*'
-  - '*.json'
-
-parser: '@typescript-eslint/parser'
-
-parserOptions:
-  ecmaVersion: 2023
-  sourceType: module
-  project:
-    - './.github/linters/tsconfig.json'
-    - './tsconfig.json'
-
-plugins:
-  - jest
-  - '@typescript-eslint'
-
-extends:
-  - eslint:recommended
-  - plugin:@typescript-eslint/eslint-recommended
-  - plugin:@typescript-eslint/recommended
-  - plugin:github/recommended
-  - plugin:jest/recommended
-
-rules:
-  {
-    'camelcase': 'off',
-    'eslint-comments/no-use': 'off',
-    'eslint-comments/no-unused-disable': 'off',
-    'i18n-text/no-en': 'off',
-    'import/no-namespace': 'off',
-    'import/no-unresolved':
-      ['error', { 'ignore': ['csv-parse/sync']}],
-    'no-console': 'off',
-    'no-unused-vars': 'off',
-    'prettier/prettier': 'error',
-    'semi': 'off',
-    '@typescript-eslint/array-type': 'error',
-    '@typescript-eslint/await-thenable': 'error',
-    '@typescript-eslint/ban-ts-comment': 'error',
-    '@typescript-eslint/consistent-type-assertions': 'error',
-    '@typescript-eslint/explicit-member-accessibility':
-      ['error', { 'accessibility': 'no-public' }],
-    '@typescript-eslint/explicit-function-return-type':
-      ['error', { 'allowExpressions': true }],
-    '@typescript-eslint/func-call-spacing': ['error', 'never'],
-    '@typescript-eslint/no-array-constructor': 'error',
-    '@typescript-eslint/no-empty-interface': 'error',
-    '@typescript-eslint/no-explicit-any': 'error',
-    '@typescript-eslint/no-extraneous-class': 'error',
-    '@typescript-eslint/no-for-in-array': 'error',
-    '@typescript-eslint/no-inferrable-types': 'error',
-    '@typescript-eslint/no-misused-new': 'error',
-    '@typescript-eslint/no-namespace': 'error',
-    '@typescript-eslint/no-non-null-assertion': 'warn',
-    '@typescript-eslint/no-require-imports': 'error',
-    '@typescript-eslint/no-unnecessary-qualifier': 'error',
-    '@typescript-eslint/no-unnecessary-type-assertion': 'error',
-    '@typescript-eslint/no-unused-vars': 'error',
-    '@typescript-eslint/no-useless-constructor': 'error',
-    '@typescript-eslint/no-var-requires': 'error',
-    '@typescript-eslint/prefer-for-of': 'warn',
-    '@typescript-eslint/prefer-function-type': 'warn',
-    '@typescript-eslint/prefer-includes': 'error',
-    '@typescript-eslint/prefer-string-starts-ends-with': 'error',
-    '@typescript-eslint/promise-function-async': 'error',
-    '@typescript-eslint/require-array-sort-compare': 'error',
-    '@typescript-eslint/restrict-plus-operands': 'error',
-    '@typescript-eslint/semi': ['error', 'never'],
-    '@typescript-eslint/space-before-function-paren': 'off',
-    '@typescript-eslint/type-annotation-spacing': 'error',
-    '@typescript-eslint/unbound-method': 'error'
-  }

.github/linters/.yaml-lint.yml

@@ -1,10 +0,0 @@
-rules:
-  document-end: disable
-  document-start:
-    level: warning
-    present: false
-  line-length:
-    level: warning
-    max: 80
-    allow-non-breakable-words: true
-    allow-non-breakable-inline-mappings: true

.github/linters/tsconfig.json

@@ -1,9 +0,0 @@
-{
-  "$schema": "https://json.schemastore.org/tsconfig",
-  "extends": "../../tsconfig.json",
-  "compilerOptions": {
-    "noEmit": true
-  },
-  "include": ["../../__tests__/**/*", "../../src/**/*"],
-  "exclude": ["../../dist", "../../node_modules", "../../coverage", "*.json"]
-}

.github/workflows/check-dist.yml

@@ -28,11 +28,11 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6.0.2
 
       - name: Setup Node.js
         id: setup-node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6.2.0
         with:
           node-version-file: .node-version
           cache: npm
@@ -60,7 +60,7 @@ jobs:
       - if: ${{ failure() && steps.diff.outcome == 'failure' }}
         name: Upload Artifact
         id: upload
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: dist
           path: dist/

.github/workflows/ci.yml

@@ -21,11 +21,11 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        uses: actions/checkout@0c366fd6a839edf440554fa01a7085ccba70ac98 # v5.0.1
 
       - name: Setup Node.js
         id: setup-node
-        uses: actions/setup-node@b39b52d1213e96004bfcb1c61a8a6fa8ab84f3e8 # v4.0.1
+        uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 # v6.2.0
         with:
           node-version-file: .node-version
           cache: npm
@@ -58,7 +58,7 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        uses: actions/checkout@0c366fd6a839edf440554fa01a7085ccba70ac98 # v5.0.1
       - name: Calculate subject digest
         id: subject
         env:

.github/workflows/codeql-analysis.yml

@@ -32,19 +32,19 @@ jobs:
     steps:
       - name: Checkout
         id: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6.0.2
 
       - name: Initialize CodeQL
         id: initialize
-        uses: github/codeql-action/init@v3
+        uses: github/codeql-action/init@v4
         with:
           languages: ${{ matrix.language }}
           source-root: src
 
       - name: Autobuild
         id: autobuild
-        uses: github/codeql-action/autobuild@v3
+        uses: github/codeql-action/autobuild@v4
 
       - name: Perform CodeQL Analysis
         id: analyze
-        uses: github/codeql-action/analyze@v3
+        uses: github/codeql-action/analyze@v4

.github/workflows/linter.yml

@@ -1,50 +0,0 @@
-name: Lint Codebase
-
-on:
-  pull_request:
-    branches:
-      - main
-  push:
-    branches:
-      - main
-
-permissions:
-  contents: read
-  packages: read
-  statuses: write
-
-jobs:
-  lint:
-    name: Lint Codebase
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout
-        id: checkout
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-
-      - name: Setup Node.js
-        id: setup-node
-        uses: actions/setup-node@v4
-        with:
-          node-version-file: .node-version
-          cache: npm
-
-      - name: Install Dependencies
-        id: install
-        run: npm ci
-
-      - name: Lint Codebase
-        id: super-linter
-        uses: super-linter/super-linter/slim@v6
-        env:
-          DEFAULT_BRANCH: main
-          FILTER_REGEX_EXCLUDE: dist/**/*
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          TYPESCRIPT_DEFAULT_STYLE: prettier
-          VALIDATE_ALL_CODEBASE: true
-          VALIDATE_JAVASCRIPT_STANDARD: false
-          VALIDATE_JSCPD: false
-          VALIDATE_GITHUB_ACTIONS: false

.node-version

@@ -1 +1 @@
-20.6.0
+24.5.0

README.md

@@ -18,12 +18,44 @@ Once the attestation has been created and signed, it will be uploaded to the GH
 attestations API and associated with the repository from which the workflow was
 initiated.
 
+When an attestation is created, the attestation is stored on the local
+filesystem used by the runner. For each attestation created, the filesystem path
+will be appended to the file `${RUNNER_TEMP}/created_attestation_paths.txt`.
+This can be used to gather all attestations created by all jobs during a the
+workflow.
+
 Attestations can be verified using the [`attestation` command in the GitHub
 CLI][5].
 
 See [Using artifact attestations to establish provenance for builds][9] for more
 information on artifact attestations.
 
+<!-- prettier-ignore-start -->
+> [!NOTE]
+> Artifact attestations are available in public repositories for all
+> current GitHub plans.
+>
+> To use artifact attestations in private or internal repositories, you must
+> be on a GitHub Enterprise Cloud plan.
+>
+> Artifact attestations are NOT supported on GitHub Enterprise Server.
+<!-- prettier-ignore-end -->
+
+## Attestation Modes
+
+This action supports three attestation modes, automatically detected based on
+the inputs you provide:
+
+<!-- markdownlint-disable MD013 -->
+
+| Mode           | When Used                                              | Description                                      |
+| -------------- | ------------------------------------------------------ | ------------------------------------------------ |
+| **Provenance** | No `sbom-path` or predicate inputs                     | Auto-generates [SLSA build provenance][10]       |
+| **SBOM**       | `sbom-path` is provided                                | Creates attestation from SPDX or CycloneDX SBOM  |
+| **Custom**     | `predicate-type`/`predicate`/`predicate-path` provided | User-supplied predicate                          |
+
+<!-- markdownlint-enable MD013 -->
+
 ## Usage
 
 Within the GitHub Actions workflow which builds some artifact you would like to
@@ -35,58 +67,71 @@ attest:
    permissions:
      id-token: write
      attestations: write
+     artifact-metadata: write
    ```
 
    The `id-token` permission gives the action the ability to mint the OIDC token
    necessary to request a Sigstore signing certificate. The `attestations`
-   permission is necessary to persist the attestation.
+   permission is necessary to persist the attestation. The `artifact-metadata`
+   permission is necessary to create the artifact storage record.
 
 1. Add the following to your workflow after your artifact has been built:
 
    ```yaml
-   - uses: actions/attest@v1
+   - uses: actions/attest@v4
      with:
        subject-path: '<PATH TO ARTIFACT>'
-       predicate-type: '<PREDICATE URI>'
-       predicate-path: '<PATH TO PREDICATE>'
    ```
 
-   The `subject-path` parameter should identify the artifact for which you want
-   to generate an attestation. The `predicate-type` can be any of the the
-   [vetted predicate types][3] or a custom value. The `predicate-path`
-   identifies a file containg the JSON-encoded predicate parameters.
+   By default, this generates a [SLSA build provenance][10] attestation. For
+   SBOM or custom attestations, see the [Attestation Modes](#attestation-modes)
+   section.
 
 ### Inputs
 
 See [action.yml](action.yml)
 
 ```yaml
-- uses: actions/attest@v1
+- uses: actions/attest@v4
   with:
     # Path to the artifact serving as the subject of the attestation. Must
-    # specify exactly one of "subject-path" or "subject-digest". May contain
-    # a glob pattern or list of paths (total subject count cannot exceed 64).
+    # specify exactly one of "subject-path", "subject-digest", or
+    # "subject-checksums". May contain a glob pattern or list of paths
+    # (total subject count cannot exceed 1024).
     subject-path:
 
     # SHA256 digest of the subject for the attestation. Must be in the form
     # "sha256:hex_digest" (e.g. "sha256:abc123..."). Must specify exactly one
-    # of "subject-path" or "subject-digest".
+    # of "subject-path", "subject-digest", or "subject-checksums".
     subject-digest:
 
-    # Subject name as it should appear in the attestation. Required unless
-    # "subject-path" is specified, in which case it will be inferred from the
-    # path.
+    # Subject name as it should appear in the attestation. Required when
+    # identifying the subject with the "subject-digest" input.
     subject-name:
 
-    # URI identifying the type of the predicate.
+    # Path to checksums file containing digest and name of subjects for
+    # attestation. Must specify exactly one of "subject-path", "subject-digest",
+    # or "subject-checksums".
+    subject-checksums:
+
+    # Path to the JSON-formatted SBOM file (SPDX or CycloneDX) to attest.
+    # File size cannot exceed 16MB. When provided, creates an SBOM attestation.
+    # Cannot be used together with "predicate-type", "predicate", or
+    # "predicate-path".
+    sbom-path:
+
+    # URI identifying the type of the predicate. Required when using "predicate"
+    # or "predicate-path" for custom attestations.
     predicate-type:
 
-    # JSON string containing the value for the attestation predicate. Must
-    # supply exactly one of "predicate-path" or "predicate".
+    # String containing the value for the attestation predicate. String length
+    # cannot exceed 16MB. Must supply exactly one of "predicate-path" or
+    # "predicate" when creating custom attestations.
     predicate:
 
-    # Path to the file which contains the JSON content for the attestation
-    # predicate. Must supply exactly one of "predicate-path" or "predicate".
+    # Path to the file which contains the content for the attestation predicate.
+    # File size cannot exceed 16MB. Must supply exactly one of "predicate-path"
+    # or "predicate" when creating custom attestations.
     predicate-path:
 
     # Whether to push the attestation to the image registry. Requires that the
@@ -94,6 +139,16 @@ See [action.yml](action.yml)
     # the "subject-digest" parameter be specified. Defaults to false.
     push-to-registry:
 
+    # Whether to create a storage record for the artifact.
+    # Requires that push-to-registry is set to true.
+    # Requires that the "subject-name" parameter specify the fully-qualified
+    # image name. Defaults to true.
+    create-storage-record:
+
+    # Whether to attach a list of generated attestations to the workflow run
+    # summary page. Defaults to true.
+    show-summary:
+
     # The GitHub token used to make authenticated API requests. Default is
     # ${{ github.token }}
     github-token:
@@ -103,27 +158,40 @@ See [action.yml](action.yml)
 
 <!-- markdownlint-disable MD013 -->
 
-| Name          | Description                                                    | Example                  |
-| ------------- | -------------------------------------------------------------- | ------------------------ |
-| `bundle-path` | Absolute path to the file containing the generated attestation | `/tmp/attestation.jsonl` |
+| Name                 | Description                                                    | Example                                          |
+| -------------------  | -------------------------------------------------------------- | ------------------------------------------------ |
+| `attestation-id`     | GitHub ID for the attestation                                  | `123456`                                         |
+| `attestation-url`    | URL for the attestation summary                                | `https://github.com/foo/bar/attestations/123456` |
+| `bundle-path`        | Absolute path to the file containing the generated attestation | `/tmp/attestation.json`                          |
+| `storage-record-ids` | GitHub IDs for the storage records                             | `987654`                                         |
 
 <!-- markdownlint-enable MD013 -->
 
 Attestations are saved in the JSON-serialized [Sigstore bundle][6] format.
 
-If multiple subjects are being attested at the same time, each attestation will
-be written to the output file on a separate line (using the [JSON Lines][7]
-format).
+If multiple subjects are being attested at the same time, a single attestation
+will be created with references to each of the supplied subjects.
+
+## Attestation Limits
+
+### Subject Limits
+
+No more than 1024 subjects can be attested at the same time.
+
+### Predicate Limits
+
+Whether supplied via the `predicate` or `predicatePath` input, the predicate
+string cannot exceed 16MB.
 
 ## Examples
 
-### Identify Subject by Path
+### Provenance Attestation (Default)
 
-For the basic use case, simply add the `attest` action to your workflow and
-supply the path to the artifact for which you want to generate attestation.
+The simplest use case - just specify the artifact path and a SLSA build
+provenance attestation is automatically generated:
 
 ```yaml
-name: build-attest
+name: build-attest-provenance
 
 on:
   workflow_dispatch:
@@ -141,20 +209,45 @@ jobs:
       - name: Build artifact
         run: make my-app
       - name: Attest
-        uses: actions/attest@v1
+        uses: actions/attest@v4
         with:
           subject-path: '${{ github.workspace }}/my-app'
-          predicate-type: 'https://example.com/predicate/v1'
-          predicate: '{}'
 ```
 
-### Identify Subjects by Wildcard
+### SBOM Attestation
 
-If you are generating multiple artifacts, you can generate an attestation for
-each by using a wildcard in the `subject-path` input.
+To create an SBOM attestation, provide the path to an SPDX or CycloneDX JSON
+file:
 
 ```yaml
-- uses: actions/attest@v1
+- name: Generate SBOM
+  run: syft . -o spdx-json > sbom.spdx.json
+
+- uses: actions/attest@v4
+  with:
+    subject-path: '${{ github.workspace }}/my-app'
+    sbom-path: '${{ github.workspace }}/sbom.spdx.json'
+```
+
+### Custom Attestation
+
+For custom attestations, provide your own predicate type and content:
+
+```yaml
+- uses: actions/attest@v4
+  with:
+    subject-path: '${{ github.workspace }}/my-app'
+    predicate-type: 'https://example.com/predicate/v1'
+    predicate: '{}'
+```
+
+### Identify Multiple Subjects
+
+If you are generating multiple artifacts, you can attest all of them at the same
+time by using a wildcard in the `subject-path` input.
+
+```yaml
+- uses: actions/attest@v4
   with:
     subject-path: 'dist/**/my-bin-*'
     predicate-type: 'https://example.com/predicate/v1'
@@ -164,6 +257,58 @@ each by using a wildcard in the `subject-path` input.
 For supported wildcards along with behavior and documentation, see
 [@actions/glob][8] which is used internally to search for files.
 
+Alternatively, you can explicitly list multiple subjects with either a comma or
+newline delimited list:
+
+```yaml
+- uses: actions/attest@v4
+  with:
+    subject-path: 'dist/foo, dist/bar'
+```
+
+```yaml
+- uses: actions/attest@v4
+  with:
+    subject-path: |
+      dist/foo
+      dist/bar
+```
+
+### Identify Subjects with Checksums File
+
+If you are using tools like
+[goreleaser](https://goreleaser.com/customization/checksum/) or
+[jreleaser](https://jreleaser.org/guide/latest/reference/checksum.html) which
+generate a checksums file you can identify the attestation subjects by passing
+the path of the checksums file to the `subject-checksums` input. Each of the
+artifacts identified in the checksums file will be listed as a subject for the
+attestation.
+
+```yaml
+- name: Calculate artifact digests
+  run: |
+    shasum -a 256 foo_0.0.1_* > subject.checksums.txt
+
+- uses: actions/attest@v4
+  with:
+    subject-checksums: subject.checksums.txt
+```
+
+<!-- markdownlint-disable MD038 -->
+
+The file referenced by the `subject-checksums` input must conform to the same
+format used by the shasum tools. Each subject should be listed on a separate
+line including the hex-encoded digest (either SHA256 or SHA512), a space, a
+single character flag indicating either binary (`*`) or text (` `) input mode,
+and the filename.
+
+<!-- markdownlint-enable MD038 -->
+
+```text
+b569bf992b287f55d78bf8ee476497e9b7e9d2bf1c338860bfb905016218c740  foo_0.0.1_darwin_amd64
+a54fc515e616cac7fcf11a49d5c5ec9ec315948a5935c1e11dd610b834b14dde  foo_0.0.1_darwin_arm64
+```
+
 ### Container Image
 
 When working with container images you can invoke the action with the
@@ -175,8 +320,12 @@ fully-qualified image name (e.g. "ghcr.io/user/app" or
 "acme.azurecr.io/user/app"). Do NOT include a tag as part of the image name --
 the specific image being attested is identified by the supplied digest.
 
-> **NOTE**: When pushing to Docker Hub, please use "index.docker.io" as the
-> registry portion of the image name.
+If the `push-to-registry` option is set to true, the Action will also
+emit an Artifact Metadata Storage Record. If you do not want to emit a
+storage record, set `create-storage-record` to `false`.
+
+> **NOTE**: When pushing to Docker Hub, please use "docker.io" as the registry
+> portion of the image name.
 
 ```yaml
 name: build-attested-image
@@ -193,6 +342,7 @@ jobs:
       packages: write
       contents: read
       attestations: write
+      artifact-metadata: write
     env:
       REGISTRY: ghcr.io
       IMAGE_NAME: ${{ github.repository }}
@@ -214,13 +364,11 @@ jobs:
           push: true
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
       - name: Attest
-        uses: actions/attest@v1
+        uses: actions/attest@v4
         id: attest
         with:
           subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           subject-digest: ${{ steps.push.outputs.digest }}
-          predicate-type: 'https://in-toto.io/attestation/release/v0.1'
-          predicate: '{"purl":"pkg:oci/..."}'
           push-to-registry: true
 ```
 
@@ -232,7 +380,7 @@ jobs:
 [5]: https://cli.github.com/manual/gh_attestation_verify
 [6]:
   https://github.com/sigstore/protobuf-specs/blob/main/protos/sigstore_bundle.proto
-[7]: https://jsonlines.org/
 [8]: https://github.com/actions/toolkit/tree/main/packages/glob#patterns
 [9]:
   https://docs.github.com/en/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds
+[10]: https://slsa.dev/spec/v1.0/provenance

__tests__/attest.test.ts

@@ -0,0 +1,195 @@
+import { jest } from '@jest/globals'
+import type { Descriptor } from '@sigstore/oci'
+// Mock functions
+const mockGetOctokit = jest.fn()
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const mockAttest = jest.fn<() => Promise<any>>()
+const mockCreateStorageRecord = jest.fn<() => Promise<number[]>>()
+const mockGetRegistryCredentials = jest.fn()
+const mockAttachArtifactToImage = jest.fn<() => Promise<Descriptor>>()
+
+// Mock @actions/github
+jest.unstable_mockModule('@actions/github', () => ({
+  getOctokit: mockGetOctokit,
+  context: {
+    repo: { owner: 'foo', repo: 'bar' },
+    payload: { repository: { visibility: 'private' } }
+  }
+}))
+
+// Mock @actions/attest
+jest.unstable_mockModule('@actions/attest', () => ({
+  attest: mockAttest,
+  createStorageRecord: mockCreateStorageRecord
+}))
+
+// Mock @sigstore/oci
+jest.unstable_mockModule('@sigstore/oci', () => ({
+  getRegistryCredentials: mockGetRegistryCredentials,
+  attachArtifactToImage: mockAttachArtifactToImage
+}))
+
+// Dynamic imports after mocking
+const { createAttestation, repoOwnerIsOrg } = await import('../src/attest')
+
+const subjectName = 'ghcr.io/foo/bar'
+const subjectDigest =
+  'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+
+const predicate = {
+  type: 'https://in-toto.io/attestation/release/v0.1',
+  params: {}
+}
+
+describe('repoOwnerIsOrg', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('returns true when repo owner is an organization', async () => {
+    mockGetOctokit.mockReturnValue({
+      rest: {
+        repos: {
+          get: jest
+            .fn<() => Promise<{ data: { owner: { type: string } } }>>()
+            .mockResolvedValue({
+              data: { owner: { type: 'Organization' } }
+            })
+        }
+      }
+    })
+
+    const result = await repoOwnerIsOrg('gh-token')
+    expect(result).toBe(true)
+  })
+
+  it('returns false when repo owner is a user', async () => {
+    mockGetOctokit.mockReturnValue({
+      rest: {
+        repos: {
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          get: jest.fn<() => Promise<any>>().mockResolvedValue({
+            data: { owner: { type: 'User' } }
+          })
+        }
+      }
+    })
+
+    const result = await repoOwnerIsOrg('gh-token')
+    expect(result).toBe(false)
+  })
+})
+
+describe('createAttestation', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+
+    // Default mock implementations
+    mockAttest.mockResolvedValue({
+      bundle: { mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' },
+      certificate: 'cert',
+      tlogID: 'tlog-123',
+      attestationID: 'att-123'
+    })
+
+    mockGetRegistryCredentials.mockReturnValue({
+      username: 'user',
+      password: 'pass'
+    })
+
+    mockAttachArtifactToImage.mockResolvedValue({
+      digest: 'sha256:abc123',
+      mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json',
+      size: 100
+    })
+  })
+
+  describe('when createStorageRecord is false', () => {
+    it('skips storage record creation', async () => {
+      const subjects = [
+        {
+          name: subjectName,
+          digest: { sha256: subjectDigest.replace('sha256:', '') }
+        }
+      ]
+
+      const result = await createAttestation(subjects, predicate, {
+        sigstoreInstance: 'github',
+        pushToRegistry: true,
+        createStorageRecord: false,
+        githubToken: 'gh-token'
+      })
+
+      expect(result.attestationDigest).toBe('sha256:abc123')
+      expect(mockCreateStorageRecord).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('when storage records are empty', () => {
+    beforeEach(() => {
+      mockGetOctokit.mockReturnValue({
+        rest: {
+          repos: {
+            // eslint-disable-next-line @typescript-eslint/no-explicit-any
+            get: jest.fn<() => Promise<any>>().mockResolvedValue({
+              data: { owner: { type: 'Organization' } }
+            })
+          }
+        }
+      })
+      mockCreateStorageRecord.mockResolvedValue([])
+    })
+
+    it('handles empty storage records gracefully', async () => {
+      const subjects = [
+        {
+          name: subjectName,
+          digest: { sha256: subjectDigest.replace('sha256:', '') }
+        }
+      ]
+
+      const result = await createAttestation(subjects, predicate, {
+        sigstoreInstance: 'github',
+        pushToRegistry: true,
+        createStorageRecord: true,
+        githubToken: 'gh-token'
+      })
+
+      expect(result.attestationDigest).toBe('sha256:abc123')
+    })
+  })
+
+  describe('when subject has unsupported protocol', () => {
+    beforeEach(() => {
+      mockGetOctokit.mockReturnValue({
+        rest: {
+          repos: {
+            // eslint-disable-next-line @typescript-eslint/no-explicit-any
+            get: jest.fn<() => Promise<any>>().mockResolvedValue({
+              data: { owner: { type: 'Organization' } }
+            })
+          }
+        }
+      })
+      mockCreateStorageRecord.mockResolvedValue([123])
+    })
+
+    it('handles unsupported protocol gracefully', async () => {
+      const subjects = [
+        {
+          name: 'http://registry.example.com/foo/bar',
+          digest: { sha256: subjectDigest.replace('sha256:', '') }
+        }
+      ]
+
+      const result = await createAttestation(subjects, predicate, {
+        sigstoreInstance: 'github',
+        pushToRegistry: true,
+        createStorageRecord: true,
+        githubToken: 'gh-token'
+      })
+
+      expect(result.attestationDigest).toBe('sha256:abc123')
+    })
+  })
+})

__tests__/detect.test.ts

@@ -0,0 +1,190 @@
+import {
+  detectAttestationType,
+  validateAttestationInputs,
+  DetectionInputs
+} from '../src/detect'
+
+describe('detectAttestationType', () => {
+  const blankInputs: DetectionInputs = {
+    sbomPath: '',
+    predicateType: '',
+    predicate: '',
+    predicatePath: ''
+  }
+
+  describe('when no inputs are provided', () => {
+    it('returns provenance', () => {
+      expect(detectAttestationType(blankInputs)).toBe('provenance')
+    })
+  })
+
+  describe('when sbom-path is provided', () => {
+    it('returns sbom', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json'
+      }
+      expect(detectAttestationType(inputs)).toBe('sbom')
+    })
+
+    it('returns sbom even when predicate inputs are also provided', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicateType: 'https://example.com/predicate'
+      }
+      expect(detectAttestationType(inputs)).toBe('sbom')
+    })
+  })
+
+  describe('when predicate-type is provided', () => {
+    it('returns custom', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+  })
+
+  describe('when predicate is provided', () => {
+    it('returns custom', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicate: '{}'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+  })
+
+  describe('when predicate-path is provided', () => {
+    it('returns custom', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+  })
+
+  describe('when predicate-type and predicate are provided', () => {
+    it('returns custom', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      }
+      expect(detectAttestationType(inputs)).toBe('custom')
+    })
+  })
+})
+
+describe('validateAttestationInputs', () => {
+  const blankInputs: DetectionInputs = {
+    sbomPath: '',
+    predicateType: '',
+    predicate: '',
+    predicatePath: ''
+  }
+
+  describe('when no inputs are provided', () => {
+    it('does not throw', () => {
+      expect(() => validateAttestationInputs(blankInputs)).not.toThrow()
+    })
+  })
+
+  describe('when sbom-path is provided alone', () => {
+    it('does not throw', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).not.toThrow()
+    })
+  })
+
+  describe('when sbom-path is combined with predicate-type', () => {
+    it('throws an error', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicateType: 'https://example.com/predicate'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /Cannot specify sbom-path together with/
+      )
+    })
+  })
+
+  describe('when sbom-path is combined with predicate', () => {
+    it('throws an error', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicate: '{}'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /Cannot specify sbom-path together with/
+      )
+    })
+  })
+
+  describe('when sbom-path is combined with predicate-path', () => {
+    it('throws an error', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        sbomPath: '/path/to/sbom.json',
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /Cannot specify sbom-path together with/
+      )
+    })
+  })
+
+  describe('when predicate is provided without predicate-type', () => {
+    it('throws an error', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicate: '{}'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /predicate-type is required/
+      )
+    })
+  })
+
+  describe('when predicate-path is provided without predicate-type', () => {
+    it('throws an error', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).toThrow(
+        /predicate-type is required/
+      )
+    })
+  })
+
+  describe('when predicate-type and predicate are provided', () => {
+    it('does not throw', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}'
+      }
+      expect(() => validateAttestationInputs(inputs)).not.toThrow()
+    })
+  })
+
+  describe('when predicate-type and predicate-path are provided', () => {
+    it('does not throw', () => {
+      const inputs: DetectionInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate',
+        predicatePath: '/path/to/predicate.json'
+      }
+      expect(() => validateAttestationInputs(inputs)).not.toThrow()
+    })
+  })
+})

__tests__/index.test.ts

@@ -1,17 +1,35 @@
 /**
  * Unit tests for the action's entrypoint, src/index.ts
  */
+import { jest } from '@jest/globals'
 
-import * as main from '../src/main'
+// Mock functions
+const mockRun = jest.fn()
+const mockGetInput = jest.fn()
+const mockGetBooleanInput = jest.fn()
 
-// Mock the action's entrypoint
-const runMock = jest.spyOn(main, 'run').mockImplementation()
+// Mock @actions/core
+jest.unstable_mockModule('@actions/core', () => ({
+  getInput: mockGetInput,
+  getBooleanInput: mockGetBooleanInput
+}))
+
+// Mock ../src/main
+jest.unstable_mockModule('../src/main', () => ({
+  run: mockRun
+}))
 
 describe('index', () => {
-  it('calls run when imported', async () => {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    require('../src/index')
+  beforeEach(() => {
+    jest.clearAllMocks()
+    mockGetBooleanInput.mockReturnValue(false)
+    mockGetInput.mockReturnValue('')
+  })
 
-    expect(runMock).toHaveBeenCalled()
+  it('calls run when imported', async () => {
+    // Dynamic import after mocking
+    await import('../src/index')
+
+    expect(mockRun).toHaveBeenCalled()
   })
 })

__tests__/main.test.ts

@@ -5,44 +5,143 @@
  * Specifically, the inputs listed in `action.yml` should be set as environment
  * variables following the pattern `INPUT_<INPUT_NAME>`.
  */
-import * as core from '@actions/core'
-import * as github from '@actions/github'
-import { mockFulcio, mockRekor, mockTSA } from '@sigstore/mock'
-import * as oci from '@sigstore/oci'
-import fs from 'fs/promises'
-import nock from 'nock'
-import os from 'os'
-import path from 'path'
-import { MockAgent, setGlobalDispatcher } from 'undici'
-import { SEARCH_PUBLIC_GOOD_URL } from '../src/endpoints'
-import * as main from '../src/main'
+import type { Predicate } from '@actions/attest'
+import { jest } from '@jest/globals'
+import type { RunInputs } from '../src/main'
 
-// Mock the GitHub Actions core library
-const infoMock = jest.spyOn(core, 'info')
-const startGroupMock = jest.spyOn(core, 'startGroup')
-const getInputMock = jest.spyOn(core, 'getInput')
-const getBooleanInputMock = jest.spyOn(core, 'getBooleanInput')
-const setOutputMock = jest.spyOn(core, 'setOutput')
-const setFailedMock = jest.spyOn(core, 'setFailed')
+// Create mock functions before mocking modules
+const infoMock = jest.fn()
+const warningMock = jest.fn()
+const startGroupMock = jest.fn()
+const endGroupMock = jest.fn()
+const setOutputMock = jest.fn()
+const setFailedMock = jest.fn()
+const debugMock = jest.fn()
 
-// Ensure that setFailed doesn't set an exit code during tests
-setFailedMock.mockImplementation(() => {})
+// OCI mocks
+const getRegCredsMock = jest.fn()
+const attachArtifactMock = jest.fn()
 
-const summaryWriteMock = jest.spyOn(core.summary, 'write')
-summaryWriteMock.mockImplementation(async () => Promise.resolve(core.summary))
+// Attest mocks
+const attestMock = jest.fn()
+const createStorageRecordMock = jest.fn()
 
-// Mock the action's main function
-const runMock = jest.spyOn(main, 'run')
+// Local attest mocks
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const createAttestationMock = jest.fn<() => Promise<any>>()
+const repoOwnerIsOrgMock = jest.fn()
+
+// Provenance mock
+const generateProvenancePredicateMock = jest.fn<() => Promise<Predicate>>()
+
+// GitHub context mock
+const mockContext = {
+  repo: { owner: 'foo', repo: 'bar' },
+  payload: { repository: { visibility: 'private' } }
+}
+const mockGetOctokit = jest.fn()
+
+// Summary mock with chainable methods
+const summaryMock = {
+  write: jest.fn().mockReturnThis(),
+  addRaw: jest.fn().mockReturnThis(),
+  addHeading: jest.fn().mockReturnThis(),
+  addLink: jest.fn().mockReturnThis(),
+  addTable: jest.fn().mockReturnThis(),
+  addBreak: jest.fn().mockReturnThis(),
+  addSeparator: jest.fn().mockReturnThis(),
+  addQuote: jest.fn().mockReturnThis(),
+  addCodeBlock: jest.fn().mockReturnThis(),
+  addList: jest.fn().mockReturnThis(),
+  addImage: jest.fn().mockReturnThis(),
+  addDetails: jest.fn().mockReturnThis(),
+  addEOL: jest.fn().mockReturnThis(),
+  emptyBuffer: jest.fn().mockReturnThis(),
+  stringify: jest.fn().mockReturnValue(''),
+  isEmptyBuffer: jest.fn().mockReturnValue(true),
+  clear: jest.fn().mockReturnThis()
+}
+
+// Mock @actions/core
+jest.unstable_mockModule('@actions/core', () => ({
+  info: infoMock,
+  warning: warningMock,
+  startGroup: startGroupMock,
+  endGroup: endGroupMock,
+  setOutput: setOutputMock,
+  setFailed: setFailedMock,
+  debug: debugMock,
+  summary: summaryMock
+}))
+
+// Mock @actions/github
+jest.unstable_mockModule('@actions/github', () => ({
+  context: mockContext,
+  getOctokit: mockGetOctokit
+}))
+
+// Mock @sigstore/oci
+jest.unstable_mockModule('@sigstore/oci', () => ({
+  getRegistryCredentials: getRegCredsMock,
+  attachArtifactToImage: attachArtifactMock
+}))
+
+// Mock @actions/attest
+jest.unstable_mockModule('@actions/attest', () => ({
+  attest: attestMock,
+  createStorageRecord: createStorageRecordMock
+}))
+
+// Mock ../src/attest
+jest.unstable_mockModule('../src/attest', () => ({
+  createAttestation: createAttestationMock,
+  repoOwnerIsOrg: repoOwnerIsOrgMock
+}))
+
+// Mock ../src/provenance
+jest.unstable_mockModule('../src/provenance', () => ({
+  generateProvenancePredicate: generateProvenancePredicateMock
+}))
+
+// Dynamic imports after mocking
+const { mockFulcio, mockRekor, mockTSA } = await import('@sigstore/mock')
+const fs = (await import('fs/promises')).default
+const nock = (await import('nock')).default
+const os = (await import('os')).default
+const path = (await import('path')).default
+const { MockAgent, setGlobalDispatcher } = await import('undici')
+const { run } = await import('../src/main')
 
 // MockAgent for mocking @actions/github
 const mockAgent = new MockAgent()
 setGlobalDispatcher(mockAgent)
 
+const defaultInputs: RunInputs = {
+  predicate: '',
+  predicateType: '',
+  predicatePath: '',
+  sbomPath: '',
+  subjectName: '',
+  subjectDigest: '',
+  subjectPath: '',
+  subjectChecksums: '',
+  pushToRegistry: false,
+  createStorageRecord: true,
+  showSummary: true,
+  githubToken: '',
+  privateSigning: false
+}
+
 describe('action', () => {
-  // Capture original environment variables and GitHub context so we can restore
-  // them after each test
+  // Capture original environment variables so we can restore after each test
   const originalEnv = process.env
-  const originalContext = { ...github.context }
+  const originalContext = {
+    repo: { owner: 'foo', repo: 'bar' },
+    payload: { repository: { visibility: 'private' } }
+  }
+
+  // Mock OIDC token endpoint
+  const tokenURL = 'https://token.url'
 
   // Fake an OIDC token
   const oidcSubject = 'foo@bar.com'
@@ -51,33 +150,38 @@ describe('action', () => {
     'base64'
   )}.}`
 
-  const subjectName = 'registry/foo/bar'
+  const subjectName = 'ghcr.io/registry/foo/bar'
   const subjectDigest =
     'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
   const predicate = '{}'
   const predicateType = 'https://in-toto.io/attestation/release/v0.1'
 
   const attestationID = '1234567890'
+  const storageRecordID = 987654321
 
   beforeEach(() => {
     jest.clearAllMocks()
 
-    // Mock OIDC token endpoint
-    const tokenURL = 'https://token.url'
-
     nock(tokenURL)
       .get('/')
       .query({ audience: 'sigstore' })
       .reply(200, { value: oidcToken })
 
-    mockAgent
-      .get('https://api.github.com')
+    const pool = mockAgent.get('https://api.github.com')
+    pool
       .intercept({
         path: /^\/repos\/.*\/.*\/attestations$/,
         method: 'post'
       })
       .reply(201, { id: attestationID })
 
+    pool
+      .intercept({
+        path: /^\/orgs\/.*\/artifacts\/metadata\/storage-record$/,
+        method: 'post'
+      })
+      .reply(200, { storage_records: [{ id: storageRecordID }] })
+
     process.env = {
       ...originalEnv,
       ACTIONS_ID_TOKEN_REQUEST_URL: tokenURL,
@@ -95,26 +199,23 @@ describe('action', () => {
   })
 
   describe('when ACTIONS_ID_TOKEN_REQUEST_URL is not set', () => {
-    const inputs = {
-      'subject-digest': subjectDigest,
-      'subject-name': subjectName,
-      'predicate-type': predicateType,
+    const inputs: RunInputs = {
+      ...defaultInputs,
+      subjectDigest,
+      subjectName,
+      predicateType,
       predicate,
-      'github-token': 'gh-token'
+      githubToken: 'gh-token'
     }
 
     beforeEach(() => {
       // Nullify the OIDC token URL
       process.env.ACTIONS_ID_TOKEN_REQUEST_URL = ''
-
-      getInputMock.mockImplementation(mockInput(inputs))
-      getBooleanInputMock.mockImplementation(() => false)
     })
 
     it('sets a failed status', async () => {
-      await main.run()
+      await run(inputs)
 
-      expect(runMock).toHaveReturned()
       expect(setFailedMock).toHaveBeenCalledWith(
         new Error(
           'missing "id-token" permission. Please add "permissions: id-token: write" to your workflow.'
@@ -124,27 +225,25 @@ describe('action', () => {
   })
 
   describe('when no inputs are provided', () => {
-    beforeEach(() => {
-      getInputMock.mockImplementation(() => '')
-    })
-
     it('sets a failed status', async () => {
-      await main.run()
+      await run(defaultInputs)
 
-      expect(runMock).toHaveReturned()
       expect(setFailedMock).toHaveBeenCalledWith(
-        new Error('One of subject-path or subject-digest must be provided')
+        new Error(
+          'One of subject-path, subject-digest, or subject-checksums must be provided'
+        )
       )
     })
   })
 
   describe('when the repository is private', () => {
-    const inputs = {
-      'subject-digest': subjectDigest,
-      'subject-name': subjectName,
-      'predicate-type': predicateType,
+    const inputs: RunInputs = {
+      ...defaultInputs,
+      subjectDigest,
+      subjectName,
+      predicateType,
       predicate,
-      'github-token': 'gh-token'
+      githubToken: 'gh-token'
     }
 
     beforeEach(async () => {
@@ -154,8 +253,15 @@ describe('action', () => {
         repo: { owner: 'foo', repo: 'bar' }
       })
 
-      getInputMock.mockImplementation(mockInput(inputs))
-      getBooleanInputMock.mockImplementation(() => false)
+      // Mock createAttestation to return expected values
+      createAttestationMock.mockResolvedValue({
+        attestationID,
+        certificate:
+          '-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----',
+        tlogID: 'tlog-123',
+        attestationDigest: 'sha256:123456',
+        bundle: { mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' }
+      })
 
       await mockFulcio({
         baseURL: 'https://fulcio.githubapp.com',
@@ -165,51 +271,28 @@ describe('action', () => {
     })
 
     it('invokes the action w/o error', async () => {
-      await main.run()
+      await run(inputs)
 
-      expect(runMock).toHaveReturned()
-      expect(setFailedMock).not.toHaveBeenCalledWith()
-      expect(infoMock).toHaveBeenNthCalledWith(
-        1,
+      expect(setFailedMock).not.toHaveBeenCalled()
+      expect(infoMock).toHaveBeenCalledWith('Attestation type: Custom')
+      expect(infoMock).toHaveBeenCalledWith(
         expect.stringMatching(
           `Attestation created for ${subjectName}@${subjectDigest}`
         )
       )
-      expect(startGroupMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching('GitHub Sigstore')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        2,
-        expect.stringMatching('-----BEGIN CERTIFICATE-----')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        3,
-        expect.stringMatching(/attestation uploaded/i)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        4,
-        expect.stringMatching(attestationID)
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        1,
-        'bundle-path',
-        expect.stringMatching('attestation.jsonl')
-      )
-      expect(setFailedMock).not.toHaveBeenCalled()
+      expect(createAttestationMock).toHaveBeenCalled()
     })
   })
 
   describe('when the repository is public', () => {
-    const getRegCredsSpy = jest.spyOn(oci, 'getRegistryCredentials')
-    const attachArtifactSpy = jest.spyOn(oci, 'attachArtifactToImage')
-
-    const inputs = {
-      'subject-digest': subjectDigest,
-      'subject-name': subjectName,
-      'predicate-type': predicateType,
+    const inputs: RunInputs = {
+      ...defaultInputs,
+      subjectDigest,
+      subjectName,
+      predicateType,
       predicate,
-      'github-token': 'gh-token'
+      githubToken: 'gh-token',
+      pushToRegistry: true
     }
 
     beforeEach(async () => {
@@ -219,10 +302,16 @@ describe('action', () => {
         repo: { owner: 'foo', repo: 'bar' }
       })
 
-      // Mock the action's inputs
-      getInputMock.mockImplementation(mockInput(inputs))
-      // This is where we mock the push-to-registry input
-      getBooleanInputMock.mockImplementation(() => true)
+      // Setup createAttestation mock
+      createAttestationMock.mockResolvedValue({
+        attestationID,
+        certificate:
+          '-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----',
+        tlogID: 'tlog-123',
+        attestationDigest: 'sha256:123456',
+        bundle: { mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' },
+        storageRecordIds: [storageRecordID]
+      })
 
       await mockFulcio({
         baseURL: 'https://fulcio.sigstore.dev',
@@ -230,70 +319,79 @@ describe('action', () => {
       })
       await mockRekor({ baseURL: 'https://rekor.sigstore.dev' })
 
-      getRegCredsSpy.mockImplementation(() => ({
-        username: 'username',
-        password: 'password'
-      }))
-      attachArtifactSpy.mockImplementation(async () =>
-        Promise.resolve({
-          digest: 'sha256:123456',
-          mediaType: 'application/vnd.cncf.notary.v2',
-          size: 123456
-        })
-      )
+      mockGetOctokit.mockReturnValue({
+        rest: {
+          repos: {
+            get: jest
+              .fn<() => Promise<{ data: { owner: { type: string } } }>>()
+              .mockResolvedValue({
+                data: { owner: { type: 'Organization' } }
+              })
+          }
+        }
+      })
     })
 
     it('invokes the action w/o error', async () => {
-      await main.run()
+      await run(inputs)
 
-      expect(runMock).toHaveReturned()
       expect(setFailedMock).not.toHaveBeenCalled()
-      expect(getRegCredsSpy).toHaveBeenCalledWith(subjectName)
-      expect(attachArtifactSpy).toHaveBeenCalled()
-      expect(infoMock).toHaveBeenNthCalledWith(
-        1,
+      expect(createAttestationMock).toHaveBeenCalled()
+      expect(infoMock).toHaveBeenCalledWith('Attestation type: Custom')
+      expect(infoMock).toHaveBeenCalledWith(
         expect.stringMatching(
           `Attestation created for ${subjectName}@${subjectDigest}`
         )
       )
-      expect(startGroupMock).toHaveBeenNthCalledWith(
-        1,
-        expect.stringMatching('Public Good Sigstore')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        2,
-        expect.stringMatching('-----BEGIN CERTIFICATE-----')
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        3,
-        expect.stringMatching(/signature uploaded/i)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        4,
-        expect.stringMatching(SEARCH_PUBLIC_GOOD_URL)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        5,
-        expect.stringMatching(/attestation uploaded/i)
-      )
-      expect(infoMock).toHaveBeenNthCalledWith(
-        6,
-        expect.stringMatching(attestationID)
-      )
-      expect(setOutputMock).toHaveBeenNthCalledWith(
-        1,
-        'bundle-path',
-        expect.stringMatching('attestation.jsonl')
-      )
+    })
+
+    it('catches error when storage record creation fails and continues', async () => {
+      // Mock createAttestation to simulate storage record failure (but still succeed overall)
+      createAttestationMock.mockResolvedValue({
+        attestationID,
+        certificate:
+          '-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----',
+        tlogID: 'tlog-123',
+        attestationDigest: 'sha256:123456',
+        bundle: { mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' }
+        // No storageRecordIDs - simulates empty/failed storage record
+      })
+
+      await run(inputs)
+
+      expect(createAttestationMock).toHaveBeenCalled()
       expect(setFailedMock).not.toHaveBeenCalled()
     })
+
+    it('does not create a storage record when the repo is owned by a user', async () => {
+      // Mock createAttestation to not return storage record IDs
+      createAttestationMock.mockResolvedValue({
+        attestationID,
+        certificate:
+          '-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----',
+        tlogID: 'tlog-123',
+        attestationDigest: 'sha256:123456',
+        bundle: { mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' }
+      })
+
+      await run(inputs)
+
+      expect(setFailedMock).not.toHaveBeenCalled()
+      expect(createAttestationMock).toHaveBeenCalled()
+      expect(infoMock).toHaveBeenCalledWith(
+        expect.stringMatching(
+          `Attestation created for ${subjectName}@${subjectDigest}`
+        )
+      )
+    })
   })
 
-  describe('when too many subjects are specified', () => {
+  describe('when the subject count is greater than 1', () => {
     let dir = ''
+    const filename = 'subject'
 
     beforeEach(async () => {
-      const filename = 'subject'
+      const subjectCount = 5
       const content = 'file content'
 
       // Set-up temp directory
@@ -301,7 +399,7 @@ describe('action', () => {
       dir = await fs.mkdtemp(tmpDir + path.sep)
 
       // Add files for glob testing
-      for (let i = 0; i < 65; i++) {
+      for (let i = 0; i < subjectCount; i++) {
         await fs.writeFile(path.join(dir, `${filename}-${i}`), content)
       }
 
@@ -311,14 +409,63 @@ describe('action', () => {
         repo: { owner: 'foo', repo: 'bar' }
       })
 
-      // Mock the action's inputs
-      getInputMock.mockImplementation(
-        mockInput({
-          predicate: '{}',
-          'subject-path': path.join(dir, `${filename}-*`)
-        })
+      // Set-up a Fulcio mock for each subject
+      await mockFulcio({
+        baseURL: 'https://fulcio.githubapp.com',
+        strict: false
+      })
+
+      // Set-up a TSA mock for each subject
+      await mockTSA({ baseURL: 'https://timestamp.githubapp.com' })
+    })
+
+    afterEach(async () => {
+      // Clean-up temp directory
+      await fs.rm(dir, { recursive: true })
+    })
+
+    it('invokes the action w/o error', async () => {
+      const inputs: RunInputs = {
+        ...defaultInputs,
+        subjectPath: path.join(dir, `${filename}-*`),
+        predicateType,
+        predicate,
+        githubToken: 'gh-token'
+      }
+      await run(inputs)
+
+      expect(setFailedMock).not.toHaveBeenCalled()
+      expect(infoMock).toHaveBeenNthCalledWith(1, 'Attestation type: Custom')
+      expect(infoMock).toHaveBeenNthCalledWith(
+        2,
+        expect.stringMatching('Attestation created for 5 subjects')
       )
     })
+  })
+
+  describe('when the subject count exceeds the max', () => {
+    let dir = ''
+    const filename = 'subject'
+
+    beforeEach(async () => {
+      const subjectCount = 1025
+      const content = 'file content'
+
+      // Set-up temp directory
+      const tmpDir = await fs.realpath(os.tmpdir())
+      dir = await fs.mkdtemp(tmpDir + path.sep)
+
+      // Add files for glob testing
+      for (let i = 0; i < subjectCount; i++) {
+        await fs.writeFile(path.join(dir, `${filename}-${i}`), content)
+      }
+
+      // Set the GH context with private repository visibility and a repo owner.
+      setGHContext({
+        payload: { repository: { visibility: 'private' } },
+        repo: { owner: 'foo', repo: 'bar' }
+      })
+    })
 
     afterEach(async () => {
       // Clean-up temp directory
@@ -326,29 +473,204 @@ describe('action', () => {
     })
 
     it('sets a failed status', async () => {
-      await main.run()
+      const inputs: RunInputs = {
+        ...defaultInputs,
+        subjectPath: path.join(dir, `${filename}-*`),
+        predicateType,
+        predicate,
+        githubToken: 'gh-token'
+      }
+      await run(inputs)
 
-      expect(runMock).toHaveReturned()
       expect(setFailedMock).toHaveBeenCalledWith(
         new Error(
-          'Too many subjects specified. The maximum number of subjects is 64.'
+          'Too many subjects specified (>1024). The maximum number of subjects is 1024.'
         )
       )
     })
   })
+
+  describe('attestation type detection', () => {
+    describe('when sbom-path is provided with predicate inputs', () => {
+      it('sets a failed status for conflicting inputs', async () => {
+        const inputs: RunInputs = {
+          ...defaultInputs,
+          subjectDigest,
+          subjectName,
+          sbomPath: '/path/to/sbom.json',
+          predicateType: 'https://example.com/predicate',
+          githubToken: 'gh-token'
+        }
+
+        await run(inputs)
+
+        expect(setFailedMock).toHaveBeenCalledWith(
+          new Error(
+            'Cannot specify sbom-path together with predicate-type, predicate, or predicate-path'
+          )
+        )
+      })
+    })
+
+    describe('when predicate is provided without predicate-type', () => {
+      it('sets a failed status for missing predicate-type', async () => {
+        const inputs: RunInputs = {
+          ...defaultInputs,
+          subjectDigest,
+          subjectName,
+          predicate: '{}',
+          githubToken: 'gh-token'
+        }
+
+        await run(inputs)
+
+        expect(setFailedMock).toHaveBeenCalledWith(
+          new Error(
+            'predicate-type is required when using predicate or predicate-path'
+          )
+        )
+      })
+    })
+
+    describe('when custom attestation inputs are provided', () => {
+      const inputs: RunInputs = {
+        ...defaultInputs,
+        subjectDigest,
+        subjectName,
+        predicateType,
+        predicate,
+        githubToken: 'gh-token'
+      }
+
+      beforeEach(async () => {
+        setGHContext({
+          payload: { repository: { visibility: 'private' } },
+          repo: { owner: 'foo', repo: 'bar' }
+        })
+
+        await mockFulcio({
+          baseURL: 'https://fulcio.githubapp.com',
+          strict: false
+        })
+        await mockTSA({ baseURL: 'https://timestamp.githubapp.com' })
+      })
+
+      it('logs the attestation type as Custom', async () => {
+        await run(inputs)
+
+        expect(setFailedMock).not.toHaveBeenCalled()
+        expect(infoMock).toHaveBeenCalledWith('Attestation type: Custom')
+      })
+    })
+
+    describe('when provenance attestation is detected', () => {
+      const inputs: RunInputs = {
+        ...defaultInputs,
+        subjectDigest,
+        subjectName,
+        githubToken: 'gh-token'
+      }
+
+      const mockProvPredicate = {
+        type: 'https://slsa.dev/provenance/v1',
+        params: { buildDefinition: {}, runDetails: {} }
+      }
+
+      beforeEach(async () => {
+        // Configure mock for provenance predicate
+        generateProvenancePredicateMock.mockResolvedValue(mockProvPredicate)
+
+        // Configure mock for createAttestation
+        createAttestationMock.mockResolvedValue({
+          attestationID: '1234567890',
+          certificate:
+            '-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----',
+          tlogID: 'tlog-123',
+          attestationDigest: 'sha256:123456',
+          bundle: { mediaType: 'application/vnd.dev.sigstore.bundle.v0.3+json' }
+        })
+
+        setGHContext({
+          payload: { repository: { visibility: 'private' } },
+          repo: { owner: 'foo', repo: 'bar' }
+        })
+
+        await mockFulcio({
+          baseURL: 'https://fulcio.githubapp.com',
+          strict: false
+        })
+        await mockTSA({ baseURL: 'https://timestamp.githubapp.com' })
+      })
+
+      it('logs the attestation type as Build Provenance and generates predicate', async () => {
+        await run(inputs)
+
+        expect(setFailedMock).not.toHaveBeenCalled()
+        expect(infoMock).toHaveBeenCalledWith(
+          'Attestation type: Build Provenance'
+        )
+      })
+    })
+
+    describe('when sbom attestation is detected', () => {
+      let tmpDir: string
+      let sbomFilePath: string
+
+      const spdxSBOM = {
+        spdxVersion: 'SPDX-2.3',
+        SPDXID: 'SPDXRef-DOCUMENT',
+        name: 'test-package',
+        packages: []
+      }
+
+      beforeEach(async () => {
+        tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'main-test-'))
+        sbomFilePath = path.join(tmpDir, 'sbom.spdx.json')
+        await fs.writeFile(sbomFilePath, JSON.stringify(spdxSBOM))
+
+        setGHContext({
+          payload: { repository: { visibility: 'private' } },
+          repo: { owner: 'foo', repo: 'bar' }
+        })
+
+        await mockFulcio({
+          baseURL: 'https://fulcio.githubapp.com',
+          strict: false
+        })
+        await mockTSA({ baseURL: 'https://timestamp.githubapp.com' })
+      })
+
+      afterEach(async () => {
+        await fs.rm(tmpDir, { recursive: true })
+      })
+
+      it('logs the attestation type as SBOM and generates predicate', async () => {
+        const inputs: RunInputs = {
+          ...defaultInputs,
+          subjectDigest,
+          subjectName,
+          sbomPath: sbomFilePath,
+          githubToken: 'gh-token'
+        }
+
+        await run(inputs)
+
+        expect(setFailedMock).not.toHaveBeenCalled()
+        expect(infoMock).toHaveBeenCalledWith('Attestation type: SBOM')
+      })
+    })
+  })
 })
 
-function mockInput(inputs: Record<string, string>): typeof core.getInput {
-  return (name: string): string => {
-    if (name in inputs) {
-      return inputs[name]
-    }
-    return ''
+// Helper to update the mock context
+function setGHContext(context: {
+  repo?: { owner: string; repo: string }
+  payload?: { repository?: { visibility: string } }
+}): void {
+  if (context.repo) {
+    mockContext.repo = context.repo
+  }
+  if (context.payload) {
+    mockContext.payload = context.payload as typeof mockContext.payload
   }
 }
-
-// Stubbing the GitHub context is a bit tricky. We need to use
-// `Object.defineProperty` because `github.context` is read-only.
-function setGHContext(context: object): void {
-  Object.defineProperty(github, 'context', { value: context })
-}

__tests__/predicate.test.ts

@@ -1,92 +1,133 @@
 import fs from 'fs/promises'
 import os from 'os'
 import path from 'path'
-import { predicateFromInputs } from '../src/predicate'
+import { predicateFromInputs, PredicateInputs } from '../src/predicate'
 
 describe('subjectFromInputs', () => {
-  afterEach(() => {
-    process.env['INPUT_PREDICATE'] = ''
-    process.env['INPUT_PREDICATE-PATH'] = ''
-    process.env['INPUT_PREDICATE-TYPE'] = ''
-  })
+  const blankInputs: PredicateInputs = {
+    predicateType: '',
+    predicate: '',
+    predicatePath: ''
+  }
 
   describe('when no inputs are provided', () => {
-    it('throws an error', () => {
-      expect(() => predicateFromInputs()).toThrow(/predicate-type/i)
+    it('throws an error', async () => {
+      await expect(predicateFromInputs(blankInputs)).rejects.toThrow(
+        /predicate-type/i
+      )
     })
   })
 
   describe('when neither predicate path nor predicate are provided', () => {
-    beforeEach(() => {
-      process.env['INPUT_PREDICATE-TYPE'] = 'https://example.com/predicate'
-    })
+    it('throws an error', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType: 'https://example.com/predicate'
+      }
 
-    it('throws an error', () => {
-      expect(() => predicateFromInputs()).toThrow(
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
         /one of predicate-path or predicate must be provided/i
       )
     })
   })
 
   describe('when both predicate path and predicate are provided', () => {
-    beforeEach(() => {
-      process.env['INPUT_PREDICATE-PATH'] = 'path/to/predicate'
-      process.env['INPUT_PREDICATE'] = '{}'
-      process.env['INPUT_PREDICATE-TYPE'] = 'https://example.com/predicate'
-    })
+    it('throws an error', async () => {
+      const inputs: PredicateInputs = {
+        predicateType: 'https://example.com/predicate',
+        predicate: '{}',
+        predicatePath: 'path/to/predicate'
+      }
 
-    it('throws an error', () => {
-      expect(() => predicateFromInputs()).toThrow(
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
         /only one of predicate-path or predicate may be provided/i
       )
     })
   })
 
   describe('when specifying a predicate path', () => {
-    let dir = ''
-    const filename = 'subject'
+    const predicateType = 'https://example.com/predicate'
     const content = '{}'
+    let predicatePath = ''
 
     beforeEach(async () => {
       // Set-up temp directory
       const tmpDir = await fs.realpath(os.tmpdir())
-      dir = await fs.mkdtemp(tmpDir + path.sep)
+      const dir = await fs.mkdtemp(tmpDir + path.sep)
+
+      const filename = 'subject'
+      predicatePath = path.join(dir, filename)
 
       // Write file to temp directory
-      await fs.writeFile(path.join(dir, filename), content)
+      await fs.writeFile(predicatePath, content)
     })
 
     afterEach(async () => {
       // Clean-up temp directory
-      await fs.rm(dir, { recursive: true })
+      await fs.rm(path.parse(predicatePath).dir, { recursive: true })
     })
 
-    beforeEach(() => {
-      process.env['INPUT_PREDICATE-PATH'] = path.join(dir, filename)
-      process.env['INPUT_PREDICATE-TYPE'] = 'https://example.com/predicate'
-    })
-
-    it('returns the predicate', () => {
-      expect(predicateFromInputs()).toEqual({
-        type: 'https://example.com/predicate',
-        params: {}
+    it('returns the predicate', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicatePath
+      }
+      await expect(predicateFromInputs(inputs)).resolves.toEqual({
+        type: predicateType,
+        params: JSON.parse(content)
       })
     })
   })
 
+  describe('when specifying a predicate path that does not exist', () => {
+    const predicateType = 'https://example.com/predicate'
+    const predicatePath = 'foo'
+
+    it('returns the predicate', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicatePath
+      }
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
+        /file not found/
+      )
+    })
+  })
+
   describe('when specifying a predicate value', () => {
+    const predicateType = 'https://example.com/predicate'
     const content = '{}'
 
-    beforeEach(() => {
-      process.env['INPUT_PREDICATE'] = content
-      process.env['INPUT_PREDICATE-TYPE'] = 'https://example.com/predicate'
-    })
+    it('returns the predicate', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicate: content
+      }
 
-    it('returns the predicate', () => {
-      expect(predicateFromInputs()).toEqual({
-        type: 'https://example.com/predicate',
-        params: {}
+      await expect(predicateFromInputs(inputs)).resolves.toEqual({
+        type: predicateType,
+        params: JSON.parse(content)
       })
     })
   })
+
+  describe('when specifying a predicate value exceeding the max size', () => {
+    const predicateType = 'https://example.com/predicate'
+    const content = JSON.stringify({ a: 'a'.repeat(16 * 1024 * 1024) })
+
+    it('throws an error', async () => {
+      const inputs: PredicateInputs = {
+        ...blankInputs,
+        predicateType,
+        predicate: content
+      }
+
+      await expect(predicateFromInputs(inputs)).rejects.toThrow(
+        /predicate string exceeds maximum/
+      )
+    })
+  })
 })

__tests__/provenance.test.ts

@@ -0,0 +1,48 @@
+import type { Predicate } from '@actions/attest'
+import { jest } from '@jest/globals'
+
+// Mock function
+const mockBuildSLSAProvenancePredicate = jest.fn<() => Promise<Predicate>>()
+
+// Mock @actions/attest
+jest.unstable_mockModule('@actions/attest', () => ({
+  buildSLSAProvenancePredicate: mockBuildSLSAProvenancePredicate
+}))
+
+// Dynamic import after mocking
+const { generateProvenancePredicate } = await import('../src/provenance')
+
+describe('generateProvenancePredicate', () => {
+  const mockPredicate = {
+    type: 'https://slsa.dev/provenance/v1',
+    params: {
+      buildDefinition: {
+        buildType: 'https://actions.github.io/buildtypes/workflow/v1'
+      },
+      runDetails: {
+        builder: { id: 'https://github.com/actions/runner' }
+      }
+    }
+  }
+
+  beforeEach(() => {
+    jest.clearAllMocks()
+    mockBuildSLSAProvenancePredicate.mockResolvedValue(mockPredicate)
+  })
+
+  it('returns the SLSA provenance predicate', async () => {
+    const result = await generateProvenancePredicate()
+
+    expect(mockBuildSLSAProvenancePredicate).toHaveBeenCalledTimes(1)
+    expect(result).toEqual(mockPredicate)
+  })
+
+  it('propagates errors from buildSLSAProvenancePredicate', async () => {
+    const error = new Error('Failed to build provenance')
+    mockBuildSLSAProvenancePredicate.mockRejectedValue(error)
+
+    await expect(generateProvenancePredicate()).rejects.toThrow(
+      'Failed to build provenance'
+    )
+  })
+})

__tests__/sbom.test.ts

@@ -0,0 +1,161 @@
+import fs from 'fs/promises'
+import os from 'os'
+import path from 'path'
+import { parseSBOMFromPath, generateSBOMPredicate, SBOM } from '../src/sbom'
+
+describe('parseSBOMFromPath', () => {
+  let tmpDir: string
+
+  beforeEach(async () => {
+    tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'sbom-test-'))
+  })
+
+  afterEach(async () => {
+    await fs.rm(tmpDir, { recursive: true })
+  })
+
+  describe('when file does not exist', () => {
+    it('throws an error', async () => {
+      await expect(parseSBOMFromPath('/nonexistent/file.json')).rejects.toThrow(
+        /ENOENT/
+      )
+    })
+  })
+
+  describe('when file contains valid SPDX SBOM', () => {
+    const spdxSBOM = {
+      spdxVersion: 'SPDX-2.3',
+      SPDXID: 'SPDXRef-DOCUMENT',
+      name: 'test-package',
+      packages: []
+    }
+
+    it('returns SBOM with type spdx', async () => {
+      const filePath = path.join(tmpDir, 'sbom.spdx.json')
+      await fs.writeFile(filePath, JSON.stringify(spdxSBOM))
+
+      const result = await parseSBOMFromPath(filePath)
+
+      expect(result.type).toBe('spdx')
+      expect(result.object).toEqual(spdxSBOM)
+    })
+  })
+
+  describe('when file contains valid CycloneDX SBOM', () => {
+    const cyclonedxSBOM = {
+      bomFormat: 'CycloneDX',
+      specVersion: '1.4',
+      serialNumber: 'urn:uuid:12345',
+      components: []
+    }
+
+    it('returns SBOM with type cyclonedx', async () => {
+      const filePath = path.join(tmpDir, 'sbom.cdx.json')
+      await fs.writeFile(filePath, JSON.stringify(cyclonedxSBOM))
+
+      const result = await parseSBOMFromPath(filePath)
+
+      expect(result.type).toBe('cyclonedx')
+      expect(result.object).toEqual(cyclonedxSBOM)
+    })
+  })
+
+  describe('when file contains invalid SBOM format', () => {
+    it('throws an error', async () => {
+      const filePath = path.join(tmpDir, 'invalid.json')
+      await fs.writeFile(filePath, JSON.stringify({ random: 'data' }))
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(
+        /Unsupported SBOM format/
+      )
+    })
+  })
+
+  describe('when file contains invalid JSON', () => {
+    it('throws an error', async () => {
+      const filePath = path.join(tmpDir, 'invalid.json')
+      await fs.writeFile(filePath, 'not valid json')
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow()
+    })
+  })
+
+  describe('when file exceeds maximum size', () => {
+    it('throws an error', async () => {
+      const filePath = path.join(tmpDir, 'large.json')
+      // Create a file larger than 16MB
+      const largeContent = 'x'.repeat(17 * 1024 * 1024)
+      await fs.writeFile(filePath, largeContent)
+
+      await expect(parseSBOMFromPath(filePath)).rejects.toThrow(
+        /SBOM file exceeds maximum allowed size/
+      )
+    })
+  })
+})
+
+describe('generateSBOMPredicate', () => {
+  describe('for SPDX SBOM', () => {
+    const spdxSBOM: SBOM = {
+      type: 'spdx',
+      object: {
+        spdxVersion: 'SPDX-2.3',
+        SPDXID: 'SPDXRef-DOCUMENT',
+        name: 'test-package'
+      }
+    }
+
+    it('returns predicate with correct SPDX type', () => {
+      const predicate = generateSBOMPredicate(spdxSBOM)
+
+      expect(predicate.type).toBe('https://spdx.dev/Document/v2.3')
+      expect(predicate.params).toEqual(spdxSBOM.object)
+    })
+  })
+
+  describe('for CycloneDX SBOM', () => {
+    const cyclonedxSBOM: SBOM = {
+      type: 'cyclonedx',
+      object: {
+        bomFormat: 'CycloneDX',
+        specVersion: '1.4',
+        serialNumber: 'urn:uuid:12345'
+      }
+    }
+
+    it('returns predicate with correct CycloneDX type', () => {
+      const predicate = generateSBOMPredicate(cyclonedxSBOM)
+
+      expect(predicate.type).toBe('https://cyclonedx.org/bom')
+      expect(predicate.params).toEqual(cyclonedxSBOM.object)
+    })
+  })
+
+  describe('for SPDX without version', () => {
+    const invalidSBOM: SBOM = {
+      type: 'spdx',
+      object: {
+        SPDXID: 'SPDXRef-DOCUMENT'
+      }
+    }
+
+    it('throws an error', () => {
+      expect(() => generateSBOMPredicate(invalidSBOM)).toThrow(
+        /Cannot find spdxVersion/
+      )
+    })
+  })
+
+  describe('for unsupported SBOM type', () => {
+    const unsupportedSBOM = {
+      type: 'unknown' as SBOM['type'],
+      object: { foo: 'bar' }
+    }
+
+    it('throws an error', () => {
+      expect(() => generateSBOMPredicate(unsupportedSBOM)).toThrow(
+        /Unsupported SBOM format/
+      )
+    })
+  })
+})

__tests__/style.test.ts

@@ -0,0 +1,15 @@
+import { highlight, mute } from '../src/style'
+
+describe('style', () => {
+  describe('highlight', () => {
+    it('adds cyan color to the string', () => {
+      expect(highlight('foo')).toBe('\x1B[36mfoo\x1B[39m')
+    })
+  })
+
+  describe('mute', () => {
+    it('adds gray color to the string', () => {
+      expect(mute('foo')).toBe('\x1B[38;5;244mfoo\x1B[39m')
+    })
+  })
+})

__tests__/subject.test.ts

@@ -2,85 +2,126 @@ import crypto from 'crypto'
 import fs from 'fs/promises'
 import os from 'os'
 import path from 'path'
-import { subjectFromInputs } from '../src/subject'
+import {
+  formatSubjectDigest,
+  subjectFromInputs,
+  SubjectInputs
+} from '../src/subject'
 
 describe('subjectFromInputs', () => {
-  afterEach(() => {
-    process.env['INPUT_SUBJECT-PATH'] = ''
-    process.env['INPUT_SUBJECT-DIGEST'] = ''
-    process.env['INPUT_SUBJECT-NAME'] = ''
-  })
+  const blankInputs: SubjectInputs = {
+    subjectPath: '',
+    subjectName: '',
+    subjectDigest: '',
+    subjectChecksums: ''
+  }
 
   describe('when no inputs are provided', () => {
     it('throws an error', async () => {
-      await expect(subjectFromInputs()).rejects.toThrow(
-        /one of subject-path or subject-digest must be provided/i
+      await expect(subjectFromInputs(blankInputs)).rejects.toThrow(
+        /one of subject-path, subject-digest, or subject-checksums must be provided/i
       )
     })
   })
 
   describe('when both subject path and subject digest are provided', () => {
-    beforeEach(() => {
-      process.env['INPUT_SUBJECT-PATH'] = 'path/to/subject'
-      process.env['INPUT_SUBJECT-DIGEST'] = 'digest'
-    })
-
     it('throws an error', async () => {
-      await expect(subjectFromInputs()).rejects.toThrow(
-        /only one of subject-path or subject-digest may be provided/i
+      const inputs: SubjectInputs = {
+        subjectName: 'foo',
+        subjectPath: 'path/to/subject',
+        subjectDigest: 'digest',
+        subjectChecksums: ''
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
+      )
+    })
+  })
+
+  describe('when both subject path and subject checksums are provided', () => {
+    it('throws an error', async () => {
+      const inputs: SubjectInputs = {
+        subjectName: '',
+        subjectPath: 'path/to/subject',
+        subjectDigest: '',
+        subjectChecksums: 'path/to/checksums'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
+      )
+    })
+  })
+
+  describe('when both subject digest and subject checksums are provided', () => {
+    it('throws an error', async () => {
+      const inputs: SubjectInputs = {
+        subjectName: 'foo',
+        subjectPath: '',
+        subjectDigest: 'digest',
+        subjectChecksums: 'path/to/checksums'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /only one of subject-path, subject-digest, or subject-checksums may be provided/i
       )
     })
   })
 
   describe('when subject digest is provided but not the name', () => {
-    beforeEach(() => {
-      process.env['INPUT_SUBJECT-DIGEST'] = 'digest'
-    })
-
     it('throws an error', async () => {
-      await expect(subjectFromInputs()).rejects.toThrow(
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectDigest: 'digest'
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
         /subject-name must be provided when using subject-digest/i
       )
     })
   })
 
   describe('when specifying a subject digest', () => {
-    const name = 'subject'
+    const name = 'Subject'
 
     describe('when the digest is malformed', () => {
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-DIGEST'] = 'digest'
-        process.env['INPUT_SUBJECT-NAME'] = 'subject'
-      })
-
       it('throws an error', async () => {
-        await expect(subjectFromInputs()).rejects.toThrow(
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectDigest: 'digest',
+          subjectName: name
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(
           /subject-digest must be in the format "sha256:<hex-digest>"/i
         )
       })
     })
 
-    describe('when the alogrithm is not supported', () => {
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-DIGEST'] = 'md5:deadbeef'
-        process.env['INPUT_SUBJECT-NAME'] = 'subject'
-      })
-
+    describe('when the algorithm is not supported', () => {
       it('throws an error', async () => {
-        await expect(subjectFromInputs()).rejects.toThrow(
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectDigest: 'md5:deadbeef',
+          subjectName: name
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(
           /subject-digest must be in the format "sha256:<hex-digest>"/i
         )
       })
     })
 
     describe('when the sha256 digest is malformed', () => {
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-DIGEST'] = 'sha256:deadbeef'
-        process.env['INPUT_SUBJECT-NAME'] = 'subject'
-      })
-
       it('throws an error', async () => {
-        await expect(subjectFromInputs()).rejects.toThrow(
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectDigest: 'sha256:deadbeef',
+          subjectName: name
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(
           /subject-digest must be in the format "sha256:<hex-digest>"/i
         )
       })
@@ -91,13 +132,14 @@ describe('subjectFromInputs', () => {
       const digest =
         '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
 
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-DIGEST'] = `${alg}:${digest}`
-        process.env['INPUT_SUBJECT-NAME'] = name
-      })
-
       it('returns the subject', async () => {
-        const subject = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectDigest: `${alg}:${digest}`,
+          subjectName: name
+        }
+
+        const subject = await subjectFromInputs(inputs)
 
         expect(subject).toBeDefined()
         expect(subject).toHaveLength(1)
@@ -105,23 +147,47 @@ describe('subjectFromInputs', () => {
         expect(subject[0].digest).toEqual({ [alg]: digest })
       })
     })
+
+    describe('when the downcaseName is true', () => {
+      const imageName = 'ghcr.io/FOO/bar'
+      const alg = 'sha256'
+      const digest =
+        '7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
+
+      it('returns the subject (with name downcased)', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectDigest: `${alg}:${digest}`,
+          subjectName: imageName,
+          downcaseName: true
+        }
+
+        const subject = await subjectFromInputs(inputs)
+
+        expect(subject).toBeDefined()
+        expect(subject).toHaveLength(1)
+        expect(subject[0].name).toEqual(imageName.toLowerCase())
+        expect(subject[0].digest).toEqual({ [alg]: digest })
+      })
+    })
   })
 
   describe('when specifying a subject path', () => {
     describe('when the file does NOT exist', () => {
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-PATH'] = '/f/a/k/e'
-      })
-
       it('throws an error', async () => {
-        await expect(subjectFromInputs()).rejects.toThrow(
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: '/f/a/k/e'
+        }
+
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(
           /could not find subject at path/i
         )
       })
     })
   })
 
-  describe('when the file eixts', () => {
+  describe('when the file exists', () => {
     let dir = ''
     const filename = 'subject'
     const content = 'file content'
@@ -152,12 +218,13 @@ describe('subjectFromInputs', () => {
     })
 
     describe('when no name is provided', () => {
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-PATH'] = path.join(dir, filename)
-      })
-
       it('returns the subject', async () => {
-        const subject = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: path.join(dir, filename)
+        }
+
+        const subject = await subjectFromInputs(inputs)
 
         expect(subject).toBeDefined()
         expect(subject).toHaveLength(1)
@@ -169,13 +236,14 @@ describe('subjectFromInputs', () => {
     describe('when a name is provided', () => {
       const name = 'mysubject'
 
-      beforeEach(() => {
-        process.env['INPUT_SUBJECT-PATH'] = path.join(dir, filename)
-        process.env['INPUT_SUBJECT-NAME'] = name
-      })
-
       it('returns the subject', async () => {
-        const subject = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: path.join(dir, filename),
+          subjectName: name
+        }
+
+        const subject = await subjectFromInputs(inputs)
 
         expect(subject).toBeDefined()
         expect(subject).toHaveLength(1)
@@ -185,17 +253,17 @@ describe('subjectFromInputs', () => {
     })
 
     describe('when a file glob is supplied', () => {
-      beforeEach(async () => {
-        process.env['INPUT_SUBJECT-PATH'] = path.join(dir, 'subject-*')
-      })
-
       it('returns the multiple subjects', async () => {
-        const subjects = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: path.join(dir, 'subject-*')
+        }
+
+        const subjects = await subjectFromInputs(inputs)
 
         expect(subjects).toBeDefined()
         expect(subjects).toHaveLength(3)
 
-        /* eslint-disable-next-line github/array-foreach */
         subjects.forEach((subject, i) => {
           expect(subject.name).toEqual(`${filename}-${i}`)
           expect(subject.digest).toEqual({ sha256: expectedDigest })
@@ -204,12 +272,13 @@ describe('subjectFromInputs', () => {
     })
 
     describe('when a file glob is supplied which also matches non-files', () => {
-      beforeEach(async () => {
-        process.env['INPUT_SUBJECT-PATH'] = `${dir}*`
-      })
-
       it('returns the subjects (excluding non-files)', async () => {
-        const subjects = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${dir}*`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
 
         expect(subjects).toBeDefined()
         expect(subjects).toHaveLength(7)
@@ -217,13 +286,13 @@ describe('subjectFromInputs', () => {
     })
 
     describe('when a comma-separated list is supplied', () => {
-      beforeEach(async () => {
-        process.env['INPUT_SUBJECT-PATH'] =
-          `${path.join(dir, 'subject-1')},${path.join(dir, 'subject-2')}`
-      })
-
       it('returns the multiple subjects', async () => {
-        const subjects = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(dir, 'subject-1')},${path.join(dir, 'subject-2')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
 
         expect(subjects).toBeDefined()
         expect(subjects).toHaveLength(2)
@@ -240,13 +309,36 @@ describe('subjectFromInputs', () => {
     })
 
     describe('when a multi-line list is supplied', () => {
-      beforeEach(async () => {
-        process.env['INPUT_SUBJECT-PATH'] =
-          `${path.join(dir, 'subject-0')}\n${path.join(dir, 'subject-2')}`
-      })
-
       it('returns the multiple subjects', async () => {
-        const subjects = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(dir, 'subject-0')}\n${path.join(dir, 'subject-2')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toBeDefined()
+        expect(subjects).toHaveLength(2)
+
+        expect(subjects).toContainEqual({
+          name: 'subject-0',
+          digest: { sha256: expectedDigest }
+        })
+        expect(subjects).toContainEqual({
+          name: 'subject-2',
+          digest: { sha256: expectedDigest }
+        })
+      })
+    })
+
+    describe('when an excluding glob is supplied', () => {
+      it('returns the multiple subjects', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(dir, 'subject-*')},!${path.join(dir, 'subject-1')}`
+        }
+
+        const subjects = await subjectFromInputs(inputs)
 
         expect(subjects).toBeDefined()
         expect(subjects).toHaveLength(2)
@@ -263,13 +355,13 @@ describe('subjectFromInputs', () => {
     })
 
     describe('when a multi-line glob list is supplied', () => {
-      beforeEach(async () => {
-        process.env['INPUT_SUBJECT-PATH'] =
-          `${path.join(dir, 'subject-*')}\n  ${path.join(dir, 'other-*')} `
-      })
-
       it('returns the multiple subjects', async () => {
-        const subjects = await subjectFromInputs()
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(dir, 'subject-*')}\n  ${path.join(dir, 'other-*')} `
+        }
+
+        const subjects = await subjectFromInputs(inputs)
 
         expect(subjects).toBeDefined()
         expect(subjects).toHaveLength(6)
@@ -301,5 +393,208 @@ describe('subjectFromInputs', () => {
         })
       })
     })
+
+    describe('when duplicate subjects are supplied', () => {
+      let otherDir = ''
+
+      // Add duplicate subject in alternate directory
+      beforeEach(async () => {
+        // Set-up temp directory
+        const tmpDir = await fs.realpath(os.tmpdir())
+        otherDir = await fs.mkdtemp(tmpDir + path.sep)
+
+        // Write file to temp directory
+        await fs.writeFile(path.join(otherDir, filename), content)
+      })
+
+      it('returns de-duplicated subjects', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectPath: `${path.join(dir, 'subject')}, ${path.join(otherDir, 'subject')} `
+        }
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toBeDefined()
+        expect(subjects).toHaveLength(1)
+      })
+    })
+  })
+
+  describe('when specifying a subject checksums file', () => {
+    const checksums = `
+187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d  demo_0.0.1_linux_amd64
+badline
+5d8b4751ef31f9440d843fcfa4e53ca2e25b1cb1f13fd355fdc7c24b41fe645293291ea9297ba3989078abb77ebbaac66be073618a9e4974dbd0361881d4c718 demo_0.0.1_darwin_arm64`
+
+    let dir = ''
+    const filename = 'checksums'
+
+    beforeEach(async () => {
+      // Set-up temp directory
+      const tmpDir = await fs.realpath(os.tmpdir())
+      dir = await fs.mkdtemp(tmpDir + path.sep)
+
+      // Write file to temp directory
+      await fs.writeFile(path.join(dir, filename), checksums)
+    })
+
+    afterEach(async () => {
+      // Clean-up temp directory
+      await fs.rm(dir, { recursive: true })
+    })
+
+    describe('when the specified path is NOT a file', () => {
+      it('throws an error', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: dir
+        }
+        await expect(subjectFromInputs(inputs)).rejects.toThrow(
+          /subject checksums file not found/i
+        )
+      })
+    })
+
+    describe('when the specific path is a file', () => {
+      it('returns the multiple subjects', async () => {
+        const inputs: SubjectInputs = {
+          ...blankInputs,
+          subjectChecksums: path.join(dir, filename)
+        }
+        const subjects = await subjectFromInputs(inputs)
+
+        expect(subjects).toBeDefined()
+        expect(subjects).toHaveLength(2)
+
+        expect(subjects).toContainEqual({
+          name: 'demo_0.0.1_linux_amd64',
+          digest: {
+            sha256:
+              '187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d'
+          }
+        })
+        expect(subjects).toContainEqual({
+          name: 'demo_0.0.1_darwin_arm64',
+          digest: {
+            sha512:
+              '5d8b4751ef31f9440d843fcfa4e53ca2e25b1cb1f13fd355fdc7c24b41fe645293291ea9297ba3989078abb77ebbaac66be073618a9e4974dbd0361881d4c718'
+          }
+        })
+      })
+    })
+  })
+
+  describe('when specifying a subject checksums string', () => {
+    const checksums = `
+f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  demo_0.0.1_linux_386
+187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d *demo_0.0.1_linux_amd64
+9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5 demo_0.0.1_linux_arm64`
+
+    it('returns the multiple subjects', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectChecksums: checksums
+      }
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects).toBeDefined()
+      expect(subjects).toHaveLength(3)
+
+      expect(subjects).toContainEqual({
+        name: 'demo_0.0.1_linux_386',
+        digest: {
+          sha256:
+            'f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e'
+        }
+      })
+      expect(subjects).toContainEqual({
+        name: 'demo_0.0.1_linux_amd64',
+        digest: {
+          sha256:
+            '187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d'
+        }
+      })
+      expect(subjects).toContainEqual({
+        name: 'demo_0.0.1_linux_arm64',
+        digest: {
+          sha256:
+            '9ecbf449e286a8a8748c161c52aa28b6b2fc64ab86f94161c5d1b3abc18156c5'
+        }
+      })
+    })
+  })
+
+  describe('when specifying a subject checksums string with duplicates', () => {
+    const checksums = `
+f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  demo_0.0.1_linux_386
+f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  demo_0.0.1_linux_386
+187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d *demo_0.0.1_linux_amd64`
+
+    it('returns de-duplicated subjects', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectChecksums: checksums
+      }
+      const subjects = await subjectFromInputs(inputs)
+
+      expect(subjects).toBeDefined()
+      expect(subjects).toHaveLength(2)
+
+      expect(subjects).toContainEqual({
+        name: 'demo_0.0.1_linux_386',
+        digest: {
+          sha256:
+            'f861e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e'
+        }
+      })
+      expect(subjects).toContainEqual({
+        name: 'demo_0.0.1_linux_amd64',
+        digest: {
+          sha256:
+            '187dcd1506a170337415589ff00c8743f19d41cc31fca246c2739dfd450d0b9d'
+        }
+      })
+    })
+  })
+
+  describe('when specifying a subject checksums string with an unrecognized digest', () => {
+    const checksums = `f861e  demo_0.0.1_linux_386`
+
+    it('throws an error', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectChecksums: checksums
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(
+        /unknown digest algorithm/i
+      )
+    })
+  })
+
+  describe('when specifying a subject checksums string with an invalid digest', () => {
+    const checksums =
+      '!!!!e68a080799ca83104630b56abb90d8dbcc5f8b5a8639cb691e269838f29e  demo_0.0.1_linux_386'
+
+    it('throws an error', async () => {
+      const inputs: SubjectInputs = {
+        ...blankInputs,
+        subjectChecksums: checksums
+      }
+
+      await expect(subjectFromInputs(inputs)).rejects.toThrow(/invalid digest/i)
+    })
+  })
+})
+
+describe('subjectDigest', () => {
+  it('returns the digest', () => {
+    const subject = {
+      name: 'foo',
+      digest: { sha1: 'deadbeef' }
+    }
+
+    const digest = formatSubjectDigest(subject)
+    expect(digest).toEqual('sha1:deadbeef')
   })
 })

action.yml

@@ -9,34 +9,50 @@ inputs:
   subject-path:
     description: >
       Path to the artifact serving as the subject of the attestation. Must
-      specify exactly one of "subject-path" or "subject-digest". May contain a
-      glob pattern or list of paths (total subject count cannot exceed 64).
+      specify exactly one of "subject-path",  "subject-digest", or
+      "subject-checksums". May contain a glob pattern or list of paths (total
+      subject count cannot exceed 1024).
     required: false
   subject-digest:
     description: >
       Digest of the subject for the attestation. Must be in the form
       "algorithm:hex_digest" (e.g. "sha256:abc123..."). Must specify exactly one
-      of "subject-path" or "subject-digest".
+      of "subject-path", "subject-digest", or "subject-checksums".
     required: false
   subject-name:
     description: >
-      Subject name as it should appear in the attestation. Required unless
-      "subject-path" is specified, in which case it will be inferred from the
-      path.
+      Subject name as it should appear in the attestation. Required when
+      identifying the subject with the "subject-digest" input.
+    required: false
+  subject-checksums:
+    description: >
+      Path to checksums file containing digest and name of subjects for
+      attestation. Must specify exactly one of "subject-path", "subject-digest",
+      or "subject-checksums".
+    required: false
+  sbom-path:
+    description: >
+      Path to the JSON-formatted SBOM file (SPDX or CycloneDX) to attest.
+      File size cannot exceed 16MB. When provided, creates an SBOM attestation.
+      Cannot be used together with "predicate-type", "predicate", or
+      "predicate-path".
     required: false
   predicate-type:
     description: >
-      URI identifying the type of the predicate.
-    required: true
+      URI identifying the type of the predicate. Required when using "predicate"
+      or "predicate-path" for custom attestations.
+    required: false
   predicate:
     description: >
-      String containing the value for the attestation predicate. Must supply
-      exactly one of "predicate-path" or "predicate".
+      String containing the value for the attestation predicate. String length
+      cannot exceed 16MB. Must supply exactly one of "predicate-path" or
+      "predicate" when creating custom attestations.
     required: false
   predicate-path:
     description: >
       Path to the file which contains the content for the attestation predicate.
-      Must supply exactly one of "predicate-path" or "predicate".
+      File size cannot exceed 16MB. Must supply exactly one of "predicate-path"
+      or "predicate" when creating custom attestations.
     required: false
   push-to-registry:
     description: >
@@ -45,6 +61,18 @@ inputs:
       the "subject-digest" parameter be specified. Defaults to false.
     default: false
     required: false
+  create-storage-record:
+    description: >
+      Whether to create a storage record for the artifact.
+      Requires that push-to-registry is set to true. Defaults to true.
+    default: true
+    required: false
+  show-summary:
+    description: >
+      Whether to attach a list of generated attestations to the workflow run
+      summary page. Defaults to true.
+    default: true
+    required: false
   github-token:
     description: >
       The GitHub token used to make authenticated API requests.
@@ -52,8 +80,14 @@ inputs:
     required: false
 outputs:
   bundle-path:
-    description: 'The path to the file containing the attestation bundle(s).'
+    description: 'The path to the file containing the attestation bundle.'
+  attestation-id:
+    description: 'The ID of the attestation.'
+  attestation-url:
+    description: 'The URL for the attestation summary.'
+  storage-record-ids:
+    description: 'The IDs of the storage records created for the artifact.'
 
 runs:
-  using: node20
+  using: node24
   main: ./dist/index.js

dist/606.index.js

@@ -0,0 +1,299 @@
+export const id = 606;
+export const ids = [606];
+export const modules = {
+
+/***/ 606:
+/***/ ((__unused_webpack___webpack_module__, __webpack_exports__, __webpack_require__) => {
+
+/* harmony export */ __webpack_require__.d(__webpack_exports__, {
+/* harmony export */   "default": () => (/* binding */ pMap)
+/* harmony export */ });
+/* unused harmony exports pMapIterable, pMapSkip */
+async function pMap(
+	iterable,
+	mapper,
+	{
+		concurrency = Number.POSITIVE_INFINITY,
+		stopOnError = true,
+		signal,
+	} = {},
+) {
+	return new Promise((resolve_, reject_) => {
+		if (iterable[Symbol.iterator] === undefined && iterable[Symbol.asyncIterator] === undefined) {
+			throw new TypeError(`Expected \`input\` to be either an \`Iterable\` or \`AsyncIterable\`, got (${typeof iterable})`);
+		}
+
+		if (typeof mapper !== 'function') {
+			throw new TypeError('Mapper function is required');
+		}
+
+		if (!((Number.isSafeInteger(concurrency) && concurrency >= 1) || concurrency === Number.POSITIVE_INFINITY)) {
+			throw new TypeError(`Expected \`concurrency\` to be an integer from 1 and up or \`Infinity\`, got \`${concurrency}\` (${typeof concurrency})`);
+		}
+
+		const result = [];
+		const errors = [];
+		const skippedIndexesMap = new Map();
+		let isRejected = false;
+		let isResolved = false;
+		let isIterableDone = false;
+		let resolvingCount = 0;
+		let currentIndex = 0;
+		const iterator = iterable[Symbol.iterator] === undefined ? iterable[Symbol.asyncIterator]() : iterable[Symbol.iterator]();
+
+		const signalListener = () => {
+			reject(signal.reason);
+		};
+
+		const cleanup = () => {
+			signal?.removeEventListener('abort', signalListener);
+		};
+
+		const resolve = value => {
+			resolve_(value);
+			cleanup();
+		};
+
+		const reject = reason => {
+			isRejected = true;
+			isResolved = true;
+			reject_(reason);
+			cleanup();
+		};
+
+		if (signal) {
+			if (signal.aborted) {
+				reject(signal.reason);
+			}
+
+			signal.addEventListener('abort', signalListener, {once: true});
+		}
+
+		const next = async () => {
+			if (isResolved) {
+				return;
+			}
+
+			const nextItem = await iterator.next();
+
+			const index = currentIndex;
+			currentIndex++;
+
+			// Note: `iterator.next()` can be called many times in parallel.
+			// This can cause multiple calls to this `next()` function to
+			// receive a `nextItem` with `done === true`.
+			// The shutdown logic that rejects/resolves must be protected
+			// so it runs only one time as the `skippedIndex` logic is
+			// non-idempotent.
+			if (nextItem.done) {
+				isIterableDone = true;
+
+				if (resolvingCount === 0 && !isResolved) {
+					if (!stopOnError && errors.length > 0) {
+						reject(new AggregateError(errors)); // eslint-disable-line unicorn/error-message
+						return;
+					}
+
+					isResolved = true;
+
+					if (skippedIndexesMap.size === 0) {
+						resolve(result);
+						return;
+					}
+
+					const pureResult = [];
+
+					// Support multiple `pMapSkip`'s.
+					for (const [index, value] of result.entries()) {
+						if (skippedIndexesMap.get(index) === pMapSkip) {
+							continue;
+						}
+
+						pureResult.push(value);
+					}
+
+					resolve(pureResult);
+				}
+
+				return;
+			}
+
+			resolvingCount++;
+
+			// Intentionally detached
+			(async () => {
+				try {
+					const element = await nextItem.value;
+
+					if (isResolved) {
+						return;
+					}
+
+					const value = await mapper(element, index);
+
+					// Use Map to stage the index of the element.
+					if (value === pMapSkip) {
+						skippedIndexesMap.set(index, value);
+					}
+
+					result[index] = value;
+
+					resolvingCount--;
+					await next();
+				} catch (error) {
+					if (stopOnError) {
+						reject(error);
+					} else {
+						errors.push(error);
+						resolvingCount--;
+
+						// In that case we can't really continue regardless of `stopOnError` state
+						// since an iterable is likely to continue throwing after it throws once.
+						// If we continue calling `next()` indefinitely we will likely end up
+						// in an infinite loop of failed iteration.
+						try {
+							await next();
+						} catch (error) {
+							reject(error);
+						}
+					}
+				}
+			})();
+		};
+
+		// Create the concurrent runners in a detached (non-awaited)
+		// promise. We need this so we can await the `next()` calls
+		// to stop creating runners before hitting the concurrency limit
+		// if the iterable has already been marked as done.
+		// NOTE: We *must* do this for async iterators otherwise we'll spin up
+		// infinite `next()` calls by default and never start the event loop.
+		(async () => {
+			for (let index = 0; index < concurrency; index++) {
+				try {
+					// eslint-disable-next-line no-await-in-loop
+					await next();
+				} catch (error) {
+					reject(error);
+					break;
+				}
+
+				if (isIterableDone || isRejected) {
+					break;
+				}
+			}
+		})();
+	});
+}
+
+function pMapIterable(
+	iterable,
+	mapper,
+	{
+		concurrency = Number.POSITIVE_INFINITY,
+		backpressure = concurrency,
+	} = {},
+) {
+	if (iterable[Symbol.iterator] === undefined && iterable[Symbol.asyncIterator] === undefined) {
+		throw new TypeError(`Expected \`input\` to be either an \`Iterable\` or \`AsyncIterable\`, got (${typeof iterable})`);
+	}
+
+	if (typeof mapper !== 'function') {
+		throw new TypeError('Mapper function is required');
+	}
+
+	if (!((Number.isSafeInteger(concurrency) && concurrency >= 1) || concurrency === Number.POSITIVE_INFINITY)) {
+		throw new TypeError(`Expected \`concurrency\` to be an integer from 1 and up or \`Infinity\`, got \`${concurrency}\` (${typeof concurrency})`);
+	}
+
+	if (!((Number.isSafeInteger(backpressure) && backpressure >= concurrency) || backpressure === Number.POSITIVE_INFINITY)) {
+		throw new TypeError(`Expected \`backpressure\` to be an integer from \`concurrency\` (${concurrency}) and up or \`Infinity\`, got \`${backpressure}\` (${typeof backpressure})`);
+	}
+
+	return {
+		async * [Symbol.asyncIterator]() {
+			const iterator = iterable[Symbol.asyncIterator] === undefined ? iterable[Symbol.iterator]() : iterable[Symbol.asyncIterator]();
+
+			const promises = [];
+			let pendingPromisesCount = 0;
+			let isDone = false;
+			let index = 0;
+
+			function trySpawn() {
+				if (isDone || !(pendingPromisesCount < concurrency && promises.length < backpressure)) {
+					return;
+				}
+
+				pendingPromisesCount++;
+
+				const promise = (async () => {
+					const {done, value} = await iterator.next();
+
+					if (done) {
+						pendingPromisesCount--;
+						return {done: true};
+					}
+
+					// Spawn if still below concurrency and backpressure limit
+					trySpawn();
+
+					try {
+						const returnValue = await mapper(await value, index++);
+
+						pendingPromisesCount--;
+
+						if (returnValue === pMapSkip) {
+							const index = promises.indexOf(promise);
+
+							if (index > 0) {
+								promises.splice(index, 1);
+							}
+						}
+
+						// Spawn if still below backpressure limit and just dropped below concurrency limit
+						trySpawn();
+
+						return {done: false, value: returnValue};
+					} catch (error) {
+						pendingPromisesCount--;
+						isDone = true;
+						return {error};
+					}
+				})();
+
+				promises.push(promise);
+			}
+
+			trySpawn();
+
+			while (promises.length > 0) {
+				const {error, done, value} = await promises[0]; // eslint-disable-line no-await-in-loop
+
+				promises.shift();
+
+				if (error) {
+					throw error;
+				}
+
+				if (done) {
+					return;
+				}
+
+				// Spawn if just dropped below backpressure limit and below the concurrency limit
+				trySpawn();
+
+				if (value === pMapSkip) {
+					continue;
+				}
+
+				yield value;
+			}
+		},
+	};
+}
+
+const pMapSkip = Symbol('skip');
+
+
+/***/ })
+
+};

dist/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

eslint.config.mjs

@@ -0,0 +1,94 @@
+import eslint from '@eslint/js'
+import importplugin from 'eslint-plugin-import'
+import jestplugin from 'eslint-plugin-jest'
+import path from 'node:path'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+  // Ignore non-project files
+  {
+    name: 'ignore',
+    ignores: ['.github', 'dist', 'coverage', '**/*.json', 'jest.setup.js', 'eslint.config.mjs']
+  },
+  // Use recommended rules from ESLint, TypeScript, and other plugins
+  eslint.configs.recommended,
+  tseslint.configs.recommendedTypeChecked,
+  jestplugin.configs['flat/recommended'],
+  importplugin.flatConfigs.recommended,
+  importplugin.flatConfigs.typescript,
+  // Override some rules
+  {
+    name: 'project-settings',
+    languageOptions: {
+      ecmaVersion: 2023,
+      parserOptions: {
+        project: [ './tsconfig.lint.json' ]
+      }
+    },
+    rules: {
+      // eslint rules
+      eqeqeq: ['error', 'smart'],
+      'func-style': ['error', 'declaration', { allowArrowFunctions: true }],
+      'no-console': 'off',
+      'no-implicit-globals': 'error',
+      'no-inner-declarations': 'error',
+      'no-invalid-this': 'error',
+      'no-return-assign': 'error',
+      'no-sequences': 'error',
+      'no-shadow': 'error',
+      'no-useless-concat': 'error',
+      'object-shorthand': ['error', 'always', { avoidQuotes: true }],
+      'one-var': ['error', 'never'],
+      'prefer-template': 'error',
+
+      // typescript-eslint rules
+      '@typescript-eslint/array-type': 'error',
+      '@typescript-eslint/consistent-type-assertions': 'error',
+      '@typescript-eslint/explicit-function-return-type': [
+        'error',
+        { allowExpressions: true }
+      ],
+      '@typescript-eslint/explicit-member-accessibility': [
+        'error',
+        { accessibility: 'no-public' }
+      ],
+      '@typescript-eslint/no-extraneous-class': 'error',
+      '@typescript-eslint/no-inferrable-types': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'warn',
+      '@typescript-eslint/no-unnecessary-qualifier': 'error',
+      '@typescript-eslint/no-unsafe-argument': 'off',
+      '@typescript-eslint/no-unsafe-assignment': 'off',
+      '@typescript-eslint/no-useless-constructor': 'error',
+      '@typescript-eslint/prefer-for-of': 'warn',
+      '@typescript-eslint/prefer-function-type': 'warn',
+      '@typescript-eslint/prefer-includes': 'error',
+      '@typescript-eslint/prefer-string-starts-ends-with': 'error',
+      '@typescript-eslint/promise-function-async': 'error',
+      '@typescript-eslint/require-array-sort-compare': 'error',
+      '@typescript-eslint/restrict-template-expressions': 'off',
+
+      // eslint-plugin-import rules
+      'import/extensions': 'error',
+      'import/first': 'error',
+      'import/no-absolute-path': 'error',
+      'import/no-commonjs': 'error',
+      'import/no-deprecated': 'warn',
+      'import/no-dynamic-require': 'error',
+      'import/no-extraneous-dependencies': 'error',
+      'import/no-mutable-exports': 'error',
+      'import/no-namespace': 'off',
+      'import/no-unresolved': ['error', { ignore: ['csv-parse/sync'] }],
+      'import/no-anonymous-default-export': [
+        'error',
+        {
+          allowAnonymousClass: false,
+          allowAnonymousFunction: false,
+          allowArray: true,
+          allowArrowFunction: false,
+          allowLiteral: true,
+          allowObject: true
+        }
+      ]
+    }
+  }
+)

jest.setup.js

@@ -1 +1,3 @@
+import { jest } from '@jest/globals'
+
 process.stdout.write = jest.fn()

package.json

@@ -1,9 +1,10 @@
 {
   "name": "actions/attest",
   "description": "Generate signed attestations for workflow artifacts",
-  "version": "1.1.1",
+  "version": "3.2.0",
   "author": "",
   "private": true,
+  "type": "module",
   "homepage": "https://github.com/actions/attest",
   "repository": {
     "type": "git",
@@ -20,24 +21,27 @@
     ".": "./dist/index.js"
   },
   "engines": {
-    "node": ">=20"
+    "node": ">=24"
   },
   "scripts": {
     "bundle": "npm run format:write && npm run package",
-    "ci-test": "jest",
+    "ci-test": "NODE_OPTIONS='--experimental-vm-modules' jest",
     "format:write": "prettier --write **/*.ts",
     "format:check": "prettier --check **/*.ts",
-    "lint:eslint": "npx eslint . -c ./.github/linters/.eslintrc.yml",
-    "lint:markdown": "npx markdownlint --config .github/linters/.markdown-lint.yml \"*.md\"",
+    "lint:eslint": "npx eslint",
+    "lint:markdown": "npx markdownlint --config .markdown-lint.yml \"*.md\"",
     "lint": "npm run lint:eslint && npm run lint:markdown",
     "package": "ncc build src/index.ts --license licenses.txt",
     "package:watch": "npm run package -- --watch",
-    "test": "jest",
+    "test": "NODE_OPTIONS='--experimental-vm-modules' jest",
     "all": "npm run format:write && npm run lint && npm run test && npm run package"
   },
   "license": "MIT",
   "jest": {
-    "preset": "ts-jest",
+    "preset": "ts-jest/presets/default-esm",
+    "extensionsToTreatAsEsm": [
+      ".ts"
+    ],
     "setupFilesAfterEnv": [
       "./jest.setup.js"
     ],
@@ -56,7 +60,12 @@
       "/dist/"
     ],
     "transform": {
-      "^.+\\.ts$": "ts-jest"
+      "^.+\\.ts$": [
+        "ts-jest",
+        {
+          "useESM": true
+        }
+      ]
     },
     "coverageReporters": [
       "json-summary",
@@ -69,33 +78,32 @@
     ]
   },
   "dependencies": {
-    "@actions/attest": "^1.2.1",
-    "@actions/core": "^1.10.1",
-    "@actions/glob": "^0.4.0",
-    "@sigstore/oci": "^0.3.2",
-    "csv-parse": "^5.5.5"
+    "@actions/attest": "^3.0.0",
+    "@actions/core": "^3.0.0",
+    "@actions/github": "^9.0.0",
+    "@actions/glob": "^0.6.1",
+    "@sigstore/oci": "^0.6.0",
+    "csv-parse": "^5.6.0"
   },
   "devDependencies": {
-    "@sigstore/mock": "^0.7.2",
-    "@types/jest": "^29.5.12",
+    "@eslint/js": "^9.39.2",
+    "@jest/globals": "^30.2.0",
+    "@sigstore/mock": "^0.11.0",
+    "@types/jest": "^30.0.0",
     "@types/make-fetch-happen": "^10.0.4",
-    "@types/node": "^20.12.10",
-    "@typescript-eslint/eslint-plugin": "^7.8.0",
-    "@typescript-eslint/parser": "^7.8.0",
-    "@vercel/ncc": "^0.38.1",
-    "eslint": "^8.57.0",
-    "eslint-plugin-github": "^4.10.2",
-    "eslint-plugin-jest": "^28.5.0",
-    "eslint-plugin-jsonc": "^2.15.1",
-    "eslint-plugin-prettier": "^5.1.3",
-    "jest": "^29.7.0",
-    "js-yaml": "^4.1.0",
-    "markdownlint-cli": "^0.40.0",
-    "nock": "^13.5.4",
-    "prettier": "^3.2.5",
-    "prettier-eslint": "^16.3.0",
-    "ts-jest": "^29.1.2",
-    "typescript": "^5.4.5",
-    "undici": "^5.28.4"
+    "@types/node": "^25.2.0",
+    "@vercel/ncc": "^0.38.4",
+    "eslint": "^9.39.2",
+    "eslint-plugin-import": "^2.32.0",
+    "eslint-plugin-jest": "^29.12.1",
+    "jest": "^30.2.0",
+    "js-yaml": "^4.1.1",
+    "markdownlint-cli": "^0.47.0",
+    "nock": "^13.5.6",
+    "prettier": "^3.8.1",
+    "ts-jest": "^29.4.6",
+    "typescript": "^5.9.3",
+    "typescript-eslint": "^8.54.0",
+    "undici": "^7.20.0"
   }
 }

src/attest.ts

@@ -0,0 +1,136 @@
+import {
+  Attestation,
+  Predicate,
+  Subject,
+  attest,
+  createStorageRecord
+} from '@actions/attest'
+import * as core from '@actions/core'
+import * as github from '@actions/github'
+import { attachArtifactToImage, getRegistryCredentials } from '@sigstore/oci'
+import { formatSubjectDigest } from './subject'
+
+const OCI_TIMEOUT = 30000
+const OCI_RETRY = 3
+
+export type SigstoreInstance = 'public-good' | 'github'
+export type AttestResult = Attestation & {
+  attestationDigest?: string
+  storageRecordIds?: number[]
+}
+
+export const createAttestation = async (
+  subjects: Subject[],
+  predicate: Predicate,
+  opts: {
+    sigstoreInstance: SigstoreInstance
+    pushToRegistry: boolean
+    createStorageRecord: boolean
+    githubToken: string
+  }
+): Promise<AttestResult> => {
+  // Sign provenance w/ Sigstore
+  const attestation = await attest({
+    subjects,
+    predicateType: predicate.type,
+    predicate: predicate.params,
+    sigstore: opts.sigstoreInstance,
+    token: opts.githubToken
+  })
+
+  const result: AttestResult = attestation
+
+  if (subjects.length === 1 && opts.pushToRegistry) {
+    const subject = subjects[0]
+    const credentials = getRegistryCredentials(subject.name)
+    const subjectDigest = formatSubjectDigest(subject)
+    const artifact = await attachArtifactToImage({
+      credentials,
+      imageName: subject.name,
+      imageDigest: subjectDigest,
+      artifact: Buffer.from(JSON.stringify(attestation.bundle)),
+      mediaType: attestation.bundle.mediaType,
+      annotations: {
+        'dev.sigstore.bundle.content': 'dsse-envelope',
+        'dev.sigstore.bundle.predicateType': predicate.type
+      },
+      fetchOpts: { timeout: OCI_TIMEOUT, retry: OCI_RETRY }
+    })
+
+    // Add the attestation's digest to the result
+    result.attestationDigest = artifact.digest
+
+    // Because creating a storage record requires the 'artifact-metadata:write'
+    // permission, we wrap this in a try/catch to avoid failing the entire
+    // attestation process if the token does not have the correct permissions.
+    if (opts.createStorageRecord) {
+      try {
+        const token = opts.githubToken
+        const isOrg = await repoOwnerIsOrg(token)
+        if (!isOrg) {
+          // The Artifact Metadata Storage Record API is only available to
+          // organizations. So if the repo owner is not an organization,
+          // storage record creation should not be attempted.
+          return result
+        }
+
+        const registryUrl = getRegistryURL(subject.name)
+        const artifactOpts = {
+          name: subject.name,
+          digest: subjectDigest
+        }
+        const packageRegistryOpts = {
+          registryUrl
+        }
+        const records = await createStorageRecord(
+          artifactOpts,
+          packageRegistryOpts,
+          token
+        )
+
+        if (!records || records.length === 0) {
+          core.warning('No storage records were created.')
+        }
+
+        result.storageRecordIds = records
+      } catch (error) {
+        core.warning(`Failed to create storage record: ${error}`)
+        core.warning(
+          'Please check that the "artifact-metadata:write" permission has been included'
+        )
+      }
+    }
+  }
+
+  return result
+}
+
+// Call the GET /repos/{owner}/{repo} endpoint to determine if the repo
+// owner is an organization. This is used to determine if storage
+// record creation should be attempted.
+export const repoOwnerIsOrg = async (githubToken: string): Promise<boolean> => {
+  const octokit = github.getOctokit(githubToken)
+  const { data: repo } = await octokit.rest.repos.get({
+    owner: github.context.repo.owner,
+    repo: github.context.repo.repo
+  })
+  return repo.owner?.type === 'Organization'
+}
+
+function getRegistryURL(subjectName: string): string {
+  let url: URL
+
+  try {
+    url = new URL(subjectName)
+  } catch {
+    url = new URL(`https://${subjectName}`)
+  }
+
+  if (url.protocol !== 'https:') {
+    throw new Error(
+      `Unsupported protocol ${url.protocol} in subject name ${subjectName}`
+    )
+  }
+
+  return url.origin
+}

src/detect.ts

@@ -0,0 +1,45 @@
+export type AttestationType = 'provenance' | 'sbom' | 'custom'
+
+export type DetectionInputs = {
+  sbomPath: string
+  predicateType: string
+  predicate: string
+  predicatePath: string
+}
+
+export const detectAttestationType = (
+  inputs: DetectionInputs
+): AttestationType => {
+  const { sbomPath, predicateType, predicate, predicatePath } = inputs
+
+  // SBOM mode takes priority
+  if (sbomPath) {
+    return 'sbom'
+  }
+
+  // Custom mode when any predicate inputs are provided
+  if (predicateType || predicate || predicatePath) {
+    return 'custom'
+  }
+
+  // Default to provenance mode
+  return 'provenance'
+}
+
+export const validateAttestationInputs = (inputs: DetectionInputs): void => {
+  const { sbomPath, predicateType, predicate, predicatePath } = inputs
+
+  // Cannot combine sbom-path with predicate inputs
+  if (sbomPath && (predicateType || predicate || predicatePath)) {
+    throw new Error(
+      'Cannot specify sbom-path together with predicate-type, predicate, or predicate-path'
+    )
+  }
+
+  // Custom mode requires predicate-type
+  if ((predicate || predicatePath) && !predicateType) {
+    throw new Error(
+      'predicate-type is required when using predicate or predicate-path'
+    )
+  }
+}

src/index.ts

@@ -1,7 +1,27 @@
 /**
  * The entrypoint for the action.
  */
-import { run } from './main'
+import * as core from '@actions/core'
+import { run, RunInputs } from './main'
 
-// eslint-disable-next-line @typescript-eslint/no-floating-promises
-run()
+const inputs: RunInputs = {
+  subjectPath: core.getInput('subject-path'),
+  subjectName: core.getInput('subject-name'),
+  subjectDigest: core.getInput('subject-digest'),
+  subjectChecksums: core.getInput('subject-checksums'),
+  sbomPath: core.getInput('sbom-path'),
+  predicateType: core.getInput('predicate-type'),
+  predicate: core.getInput('predicate'),
+  predicatePath: core.getInput('predicate-path'),
+  pushToRegistry: core.getBooleanInput('push-to-registry'),
+  createStorageRecord: core.getBooleanInput('create-storage-record'),
+  showSummary: core.getBooleanInput('show-summary'),
+  githubToken: core.getInput('github-token'),
+  // undocumented -- not part of public interface
+  privateSigning: ['true', 'True', 'TRUE', '1'].includes(
+    core.getInput('private-signing')
+  )
+}
+
+/* eslint-disable-next-line @typescript-eslint/no-floating-promises */
+run(inputs)

src/main.ts

@@ -1,26 +1,44 @@
-import { Attestation, Predicate, Subject, attest } from '@actions/attest'
 import * as core from '@actions/core'
 import * as github from '@actions/github'
-import { attachArtifactToImage, getRegistryCredentials } from '@sigstore/oci'
-import fs from 'fs'
+import fs from 'fs/promises'
 import os from 'os'
 import path from 'path'
+import { AttestResult, SigstoreInstance, createAttestation } from './attest'
+import {
+  AttestationType,
+  DetectionInputs,
+  detectAttestationType,
+  validateAttestationInputs
+} from './detect'
 import { SEARCH_PUBLIC_GOOD_URL } from './endpoints'
-import { predicateFromInputs } from './predicate'
-import { subjectFromInputs } from './subject'
+import { PredicateInputs, predicateFromInputs } from './predicate'
+import { generateProvenancePredicate } from './provenance'
+import { generateSBOMPredicate, parseSBOMFromPath } from './sbom'
+import * as style from './style'
+import {
+  SubjectInputs,
+  formatSubjectDigest,
+  subjectFromInputs
+} from './subject'
 
-type SigstoreInstance = 'public-good' | 'github'
-type AttestedSubject = { subject: Subject; attestationID: string }
+import type { Predicate, Subject } from '@actions/attest'
 
-const COLOR_CYAN = '\x1B[36m'
-const COLOR_GRAY = '\x1B[38;5;244m'
-const COLOR_DEFAULT = '\x1B[39m'
-const ATTESTATION_FILE_NAME = 'attestation.jsonl'
+const ATTESTATION_FILE_NAME = 'attestation.json'
+const ATTESTATION_PATHS_FILE_NAME = 'created_attestation_paths.txt'
 
-const MAX_SUBJECT_COUNT = 64
+export type SBOMInputs = {
+  sbomPath: string
+}
 
-const OCI_TIMEOUT = 2000
-const OCI_RETRY = 3
+export type RunInputs = SubjectInputs &
+  PredicateInputs &
+  SBOMInputs & {
+    pushToRegistry: boolean
+    createStorageRecord: boolean
+    githubToken: string
+    showSummary: boolean
+    privateSigning: boolean
+  }
 
 /* istanbul ignore next */
 const logHandler = (level: string, ...args: unknown[]): void => {
@@ -34,7 +52,7 @@ const logHandler = (level: string, ...args: unknown[]): void => {
  * The main function for the action.
  * @returns {Promise<void>} Resolves when the action is complete.
  */
-export async function run(): Promise<void> {
+export async function run(inputs: RunInputs): Promise<void> {
   process.on('log', logHandler)
 
   // Provenance visibility will be public ONLY if we can confirm that the
@@ -42,61 +60,83 @@ export async function run(): Promise<void> {
   // Otherwise, it will be private.
   const sigstoreInstance: SigstoreInstance =
     github.context.payload.repository?.visibility === 'public' &&
-    core.getInput('private-signing') !== 'true'
+    !inputs.privateSigning
       ? 'public-good'
       : 'github'
 
   try {
-    const atts: AttestedSubject[] = []
     if (!process.env.ACTIONS_ID_TOKEN_REQUEST_URL) {
       throw new Error(
         'missing "id-token" permission. Please add "permissions: id-token: write" to your workflow.'
       )
     }
 
-    // Gather list of subjets
-    const subjects = await subjectFromInputs()
-    if (subjects.length > MAX_SUBJECT_COUNT) {
-      throw new Error(
-        `Too many subjects specified. The maximum number of subjects is ${MAX_SUBJECT_COUNT}.`
-      )
+    // Detect attestation type and validate inputs
+    const detectionInputs: DetectionInputs = {
+      sbomPath: inputs.sbomPath,
+      predicateType: inputs.predicateType,
+      predicate: inputs.predicate,
+      predicatePath: inputs.predicatePath
     }
+    validateAttestationInputs(detectionInputs)
+    const attestationType = detectAttestationType(detectionInputs)
+    logAttestationType(attestationType)
 
-    const predicate = predicateFromInputs()
-    const outputPath = path.join(tempDir(), ATTESTATION_FILE_NAME)
+    const subjects = await subjectFromInputs({
+      ...inputs,
+      downcaseName: inputs.pushToRegistry
+    })
 
-    // Generate attestations for each subject serially
-    for (const subject of subjects) {
-      const att = await createAttestation(subject, predicate, sigstoreInstance)
+    // Generate predicate based on attestation type
+    const predicate = await getPredicateForType(attestationType, inputs)
 
-      // Write attestation bundle to output file
-      fs.writeFileSync(outputPath, JSON.stringify(att.bundle) + os.EOL, {
+    const outputPath = path.join(await tempDir(), ATTESTATION_FILE_NAME)
+    core.setOutput('bundle-path', outputPath)
+
+    const att = await createAttestation(subjects, predicate, {
+      sigstoreInstance,
+      pushToRegistry: inputs.pushToRegistry,
+      createStorageRecord: inputs.createStorageRecord,
+      githubToken: inputs.githubToken
+    })
+
+    logAttestation(subjects, att, sigstoreInstance)
+
+    // Write attestation bundle to output file
+    await fs.writeFile(outputPath, JSON.stringify(att.bundle) + os.EOL, {
+      encoding: 'utf-8',
+      flag: 'a'
+    })
+
+    const baseDir = process.env.RUNNER_TEMP
+    /* istanbul ignore else */
+    if (baseDir) {
+      const outputSummaryPath = path.join(baseDir, ATTESTATION_PATHS_FILE_NAME)
+      // Append the output path to the attestations paths file
+      await fs.appendFile(outputSummaryPath, outputPath + os.EOL, {
         encoding: 'utf-8',
         flag: 'a'
       })
-
-      if (att.attestationID) {
-        atts.push({ subject, attestationID: att.attestationID })
-      }
-    }
-
-    if (atts.length > 0) {
-      core.summary.addHeading(
-        /* istanbul ignore next */
-        atts.length > 1 ? 'Attestations Created' : 'Attestation Created',
-        3
+    } else {
+      core.warning(
+        'RUNNER_TEMP environment variable is not set. Cannot write attestation paths file.'
       )
-
-      for (const { subject, attestationID } of atts) {
-        core.summary.addLink(
-          `${subject.name}@${subjectDigest(subject)}`,
-          attestationURL(attestationID)
-        )
-      }
-      core.summary.write()
     }
 
-    core.setOutput('bundle-path', outputPath)
+    /* istanbul ignore else */
+    if (att.attestationID) {
+      core.setOutput('attestation-id', att.attestationID)
+      core.setOutput('attestation-url', attestationURL(att.attestationID))
+    }
+
+    if (att.storageRecordIds) {
+      core.setOutput('storage-record-ids', att.storageRecordIds.join(','))
+    }
+
+    /* istanbul ignore else */
+    if (inputs.showSummary) {
+      await logSummary(att)
+    }
   } catch (err) {
     // Fail the workflow run if an error occurs
     core.setFailed(
@@ -108,7 +148,9 @@ export async function run(): Promise<void> {
     if (err instanceof Error && 'cause' in err) {
       const innerErr = err.cause
       core.info(
-        mute(innerErr instanceof Error ? innerErr.toString() : `${innerErr}`)
+        style.mute(
+          innerErr instanceof Error ? innerErr.toString() : `${innerErr}`
+        )
       )
     }
   } finally {
@@ -116,27 +158,24 @@ export async function run(): Promise<void> {
   }
 }
 
-const createAttestation = async (
-  subject: Subject,
-  predicate: Predicate,
+// Log details about the attestation to the GitHub Actions run
+const logAttestation = (
+  subjects: Subject[],
+  attestation: AttestResult,
   sigstoreInstance: SigstoreInstance
-): Promise<Attestation> => {
-  // Sign provenance w/ Sigstore
-  const attestation = await attest({
-    subjectName: subject.name,
-    subjectDigest: subject.digest,
-    predicateType: predicate.type,
-    predicate: predicate.params,
-    sigstore: sigstoreInstance,
-    token: core.getInput('github-token')
-  })
-
-  core.info(`Attestation created for ${subject.name}@${subjectDigest(subject)}`)
+): void => {
+  if (subjects.length === 1) {
+    core.info(
+      `Attestation created for ${subjects[0].name}@${formatSubjectDigest(subjects[0])}`
+    )
+  } else {
+    core.info(`Attestation created for ${subjects.length} subjects`)
+  }
 
   const instanceName =
     sigstoreInstance === 'public-good' ? 'Public Good' : 'GitHub'
   core.startGroup(
-    highlight(
+    style.highlight(
       `Attestation signed using certificate from ${instanceName} Sigstore instance`
     )
   )
@@ -145,45 +184,44 @@ const createAttestation = async (
 
   if (attestation.tlogID) {
     core.info(
-      highlight('Attestation signature uploaded to Rekor transparency log')
+      style.highlight(
+        'Attestation signature uploaded to Rekor transparency log'
+      )
     )
     core.info(`${SEARCH_PUBLIC_GOOD_URL}?logIndex=${attestation.tlogID}`)
   }
 
+  /* istanbul ignore else */
   if (attestation.attestationID) {
-    core.info(highlight('Attestation uploaded to repository'))
+    core.info(style.highlight('Attestation uploaded to repository'))
     core.info(attestationURL(attestation.attestationID))
   }
 
-  if (core.getBooleanInput('push-to-registry', { required: false })) {
-    const credentials = getRegistryCredentials(subject.name)
-    const artifact = await attachArtifactToImage({
-      credentials,
-      imageName: subject.name,
-      imageDigest: subjectDigest(subject),
-      artifact: Buffer.from(JSON.stringify(attestation.bundle)),
-      mediaType: attestation.bundle.mediaType,
-      annotations: {
-        'dev.sigstore.bundle.content': 'dsse-envelope',
-        'dev.sigstore.bundle.predicateType': core.getInput('predicate-type')
-      },
-      fetchOpts: { timeout: OCI_TIMEOUT, retry: OCI_RETRY }
-    })
-    core.info(highlight('Attestation uploaded to registry'))
-    core.info(`${subject.name}@${artifact.digest}`)
+  if (attestation.attestationDigest) {
+    core.info(style.highlight('Attestation uploaded to registry'))
+    core.info(`${subjects[0].name}@${attestation.attestationDigest}`)
   }
 
-  return attestation
+  if (attestation.storageRecordIds && attestation.storageRecordIds.length > 0) {
+    core.info(style.highlight('Storage record created'))
+    core.info(`Storage record IDs: ${attestation.storageRecordIds.join(',')}`)
+  }
 }
 
-// Emphasis string using ANSI color codes
-const highlight = (str: string): string => `${COLOR_CYAN}${str}${COLOR_DEFAULT}`
+// Attach summary information to the GitHub Actions run
+const logSummary = async (attestation: AttestResult): Promise<void> => {
+  const { attestationID } = attestation
 
-// De-emphasize string using ANSI color codes
-/* istanbul ignore next */
-const mute = (str: string): string => `${COLOR_GRAY}${str}${COLOR_DEFAULT}`
+  /* istanbul ignore else */
+  if (attestationID) {
+    const url = attestationURL(attestationID)
+    core.summary.addHeading('Attestation Created', 3)
+    core.summary.addList([`<a href="${url}">${url}</a>`])
+    await core.summary.write()
+  }
+}
 
-const tempDir = (): string => {
+const tempDir = async (): Promise<string> => {
   const basePath = process.env['RUNNER_TEMP']
 
   /* istanbul ignore if */
@@ -191,15 +229,35 @@ const tempDir = (): string => {
     throw new Error('Missing RUNNER_TEMP environment variable')
   }
 
-  return fs.mkdtempSync(path.join(basePath, path.sep))
-}
-
-// Returns the subject's digest as a formatted string of the form
-// "<algorithm>:<digest>".
-const subjectDigest = (subject: Subject): string => {
-  const alg = Object.keys(subject.digest).sort()[0]
-  return `${alg}:${subject.digest[alg]}`
+  return fs.mkdtemp(path.join(basePath, path.sep))
 }
 
 const attestationURL = (id: string): string =>
   `${github.context.serverUrl}/${github.context.repo.owner}/${github.context.repo.repo}/attestations/${id}`
+
+// Log the detected attestation type
+const logAttestationType = (type: AttestationType): void => {
+  const typeLabels: Record<AttestationType, string> = {
+    provenance: 'Build Provenance',
+    sbom: 'SBOM',
+    custom: 'Custom'
+  }
+  core.info(`Attestation type: ${typeLabels[type]}`)
+}
+
+// Generate predicate based on attestation type
+const getPredicateForType = async (
+  type: AttestationType,
+  inputs: RunInputs
+): Promise<Predicate> => {
+  switch (type) {
+    case 'provenance':
+      return generateProvenancePredicate()
+    case 'sbom': {
+      const sbom = await parseSBOMFromPath(inputs.sbomPath)
+      return generateSBOMPredicate(sbom)
+    }
+    case 'custom':
+      return predicateFromInputs(inputs)
+  }
+}

src/predicate.ts

@@ -1,26 +1,62 @@
-import * as core from '@actions/core'
-import fs from 'fs'
+import fs from 'fs/promises'
 
 import type { Predicate } from '@actions/attest'
 
+export type PredicateInputs = {
+  predicateType: string
+  predicate: string
+  predicatePath: string
+}
+
+const MAX_PREDICATE_SIZE_BYTES = 16 * 1024 * 1024
+
 // Returns the predicate specified by the action's inputs. The predicate value
 // may be specified as a path to a file or as a string.
-export const predicateFromInputs = (): Predicate => {
-  const predicateType = core.getInput('predicate-type', { required: true })
-  const predicateStr = core.getInput('predicate', { required: false })
-  const predicatePath = core.getInput('predicate-path', { required: false })
+export const predicateFromInputs = async (
+  inputs: PredicateInputs
+): Promise<Predicate> => {
+  const { predicateType, predicate, predicatePath } = inputs
 
-  if (!predicatePath && !predicateStr) {
+  if (!predicateType) {
+    throw new Error('predicate-type must be provided')
+  }
+
+  if (!predicatePath && !predicate) {
     throw new Error('One of predicate-path or predicate must be provided')
   }
 
-  if (predicatePath && predicateStr) {
+  if (predicatePath && predicate) {
     throw new Error('Only one of predicate-path or predicate may be provided')
   }
 
-  const params = predicatePath
-    ? fs.readFileSync(predicatePath, 'utf-8')
-    : predicateStr
+  let params: string = predicate
+
+  if (predicatePath) {
+    try {
+      await fs.access(predicatePath)
+    } catch {
+      throw new Error(`predicate file not found: ${predicatePath}`)
+    }
+
+    const stat = await fs.stat(predicatePath)
+
+    /* istanbul ignore next */
+    if (stat.size > MAX_PREDICATE_SIZE_BYTES) {
+      throw new Error(
+        `predicate file exceeds maximum allowed size: ${MAX_PREDICATE_SIZE_BYTES} bytes`
+      )
+    }
+
+    params = await fs.readFile(predicatePath, 'utf-8')
+  } else {
+    if (predicate.length > MAX_PREDICATE_SIZE_BYTES) {
+      throw new Error(
+        `predicate string exceeds maximum allowed size: ${MAX_PREDICATE_SIZE_BYTES} bytes`
+      )
+    }
+
+    params = predicate
+  }
 
   return { type: predicateType, params: JSON.parse(params) }
 }

src/provenance.ts

@@ -0,0 +1,7 @@
+import { buildSLSAProvenancePredicate } from '@actions/attest'
+
+import type { Predicate } from '@actions/attest'
+
+export const generateProvenancePredicate = async (): Promise<Predicate> => {
+  return buildSLSAProvenancePredicate()
+}

src/sbom.ts

@@ -0,0 +1,87 @@
+import fs from 'fs/promises'
+
+import type { Predicate } from '@actions/attest'
+
+export type SBOM = {
+  type: 'spdx' | 'cyclonedx'
+  object: object
+}
+
+// SBOMs cannot exceed 16MB.
+const MAX_SBOM_SIZE_BYTES = 16 * 1024 * 1024
+
+export const parseSBOMFromPath = async (filePath: string): Promise<SBOM> => {
+  const fileContent = await fs.readFile(filePath, 'utf8')
+
+  const stats = await fs.stat(filePath)
+  if (stats.size > MAX_SBOM_SIZE_BYTES) {
+    throw new Error(
+      `SBOM file exceeds maximum allowed size: ${MAX_SBOM_SIZE_BYTES} bytes`
+    )
+  }
+
+  const sbom = JSON.parse(fileContent) as object
+
+  if (checkIsSPDX(sbom)) {
+    return { type: 'spdx', object: sbom }
+  } else if (checkIsCycloneDX(sbom)) {
+    return { type: 'cyclonedx', object: sbom }
+  }
+
+  throw new Error(
+    'Unsupported SBOM format. Must be valid SPDX or CycloneDX JSON.'
+  )
+}
+
+const checkIsSPDX = (sbomObject: {
+  spdxVersion?: string
+  SPDXID?: string
+}): boolean => {
+  return !!(sbomObject?.spdxVersion && sbomObject?.SPDXID)
+}
+
+const checkIsCycloneDX = (sbomObject: {
+  bomFormat?: string
+  serialNumber?: string
+  specVersion?: string
+}): boolean => {
+  return !!(
+    sbomObject?.bomFormat &&
+    sbomObject?.serialNumber &&
+    sbomObject?.specVersion
+  )
+}
+
+export const generateSBOMPredicate = (sbom: SBOM): Predicate => {
+  switch (sbom.type) {
+    case 'spdx':
+      return generateSPDXPredicate(sbom.object)
+    case 'cyclonedx':
+      return generateCycloneDXPredicate(sbom.object)
+    default:
+      throw new Error('Unsupported SBOM format')
+  }
+}
+
+// ref: https://github.com/in-toto/attestation/blob/main/spec/predicates/spdx.md
+const generateSPDXPredicate = (sbom: object): Predicate => {
+  const spdxVersion = (sbom as { spdxVersion?: string })?.['spdxVersion']
+  if (!spdxVersion) {
+    throw new Error('Cannot find spdxVersion in the SBOM')
+  }
+
+  const version = spdxVersion.split('-')[1]
+
+  return {
+    type: `https://spdx.dev/Document/v${version}`,
+    params: sbom
+  }
+}
+
+// ref: https://github.com/in-toto/attestation/blob/main/spec/predicates/cyclonedx.md
+const generateCycloneDXPredicate = (sbom: object): Predicate => {
+  return {
+    type: 'https://cyclonedx.org/bom',
+    params: sbom
+  }
+}

src/style.ts

@@ -0,0 +1,11 @@
+const COLOR_CYAN = '\x1B[36m'
+const COLOR_GRAY = '\x1B[38;5;244m'
+const COLOR_DEFAULT = '\x1B[39m'
+
+// Emphasis string using ANSI color codes
+export const highlight = (str: string): string =>
+  `${COLOR_CYAN}${str}${COLOR_DEFAULT}`
+
+// De-emphasize string using ANSI color codes
+export const mute = (str: string): string =>
+  `${COLOR_GRAY}${str}${COLOR_DEFAULT}`

src/subject.ts

@@ -1,30 +1,53 @@
-import * as core from '@actions/core'
 import * as glob from '@actions/glob'
+import assert from 'assert'
 import crypto from 'crypto'
 import { parse } from 'csv-parse/sync'
-import fs from 'fs'
+import { createReadStream } from 'fs'
+import fs from 'fs/promises'
+import os from 'os'
 import path from 'path'
 
 import type { Subject } from '@actions/attest'
 
+const MAX_SUBJECT_COUNT = 1024
+const MAX_SUBJECT_CHECKSUM_SIZE_BYTES = 512 * MAX_SUBJECT_COUNT
 const DIGEST_ALGORITHM = 'sha256'
+const HEX_STRING_RE = /^[0-9a-fA-F]+$/
 
+export type SubjectInputs = {
+  subjectPath: string
+  subjectName: string
+  subjectDigest: string
+  subjectChecksums: string
+  downcaseName?: boolean
+}
 // Returns the subject specified by the action's inputs. The subject may be
 // specified as a path to a file or as a digest. If a path is provided, the
 // file's digest is calculated and returned along with the subject's name. If a
 // digest is provided, the name must also be provided.
-export const subjectFromInputs = async (): Promise<Subject[]> => {
-  const subjectPath = core.getInput('subject-path', { required: false })
-  const subjectDigest = core.getInput('subject-digest', { required: false })
-  const subjectName = core.getInput('subject-name', { required: false })
+export const subjectFromInputs = async (
+  inputs: SubjectInputs
+): Promise<Subject[]> => {
+  const {
+    subjectPath,
+    subjectDigest,
+    subjectName,
+    subjectChecksums,
+    downcaseName
+  } = inputs
 
-  if (!subjectPath && !subjectDigest) {
-    throw new Error('One of subject-path or subject-digest must be provided')
+  const enabledInputs = [subjectPath, subjectDigest, subjectChecksums].filter(
+    Boolean
+  )
+  if (enabledInputs.length === 0) {
+    throw new Error(
+      'One of subject-path, subject-digest, or subject-checksums must be provided'
+    )
   }
 
-  if (subjectPath && subjectDigest) {
+  if (enabledInputs.length > 1) {
     throw new Error(
-      'Only one of subject-path or subject-digest may be provided'
+      'Only one of subject-path, subject-digest, or subject-checksums may be provided'
     )
   }
 
@@ -32,47 +55,78 @@ export const subjectFromInputs = async (): Promise<Subject[]> => {
     throw new Error('subject-name must be provided when using subject-digest')
   }
 
-  if (subjectPath) {
-    return await getSubjectFromPath(subjectPath, subjectName)
-  } else {
-    return [getSubjectFromDigest(subjectDigest, subjectName)]
+  // If push-to-registry is enabled, ensure the subject name is lowercase
+  // to conform to OCI image naming conventions
+  const name = downcaseName ? subjectName.toLowerCase() : subjectName
+
+  switch (true) {
+    case !!subjectPath:
+      return getSubjectFromPath(subjectPath, name)
+    case !!subjectDigest:
+      return [getSubjectFromDigest(subjectDigest, name)]
+    case !!subjectChecksums:
+      return await getSubjectFromChecksums(subjectChecksums)
+    /* istanbul ignore next */
+    default:
+      // This should be unreachable, but TS requires a default case
+      assert.fail('unreachable')
   }
 }
 
+// Returns the subject's digest as a formatted string of the form
+// "<algorithm>:<digest>".
+export const formatSubjectDigest = (subject: Subject): string => {
+  const alg = Object.keys(subject.digest).sort()[0]
+  return `${alg}:${subject.digest[alg]}`
+}
+
 // Returns the subject specified by the path to a file. The file's digest is
 // calculated and returned along with the subject's name.
 const getSubjectFromPath = async (
   subjectPath: string,
   subjectName?: string
 ): Promise<Subject[]> => {
-  const subjects: Subject[] = []
+  const digestedSubjects: Subject[] = []
 
   // Parse the list of subject paths
-  const subjectPaths = parseList(subjectPath)
+  const subjectPaths = parseSubjectPathList(subjectPath).join('\n')
 
-  for (const subPath of subjectPaths) {
-    // Expand the globbed path to a list of files
-    /* eslint-disable-next-line github/no-then */
-    const files = await glob.create(subPath).then(async g => g.glob())
+  // Expand the globbed paths to a list of actual paths
+  const paths = await glob.create(subjectPaths).then(async g => g.glob())
 
-    for (const file of files) {
-      // Skip anything that is NOT a file
-      if (!fs.statSync(file).isFile()) {
-        continue
+  // Filter path list to just the files (not directories), enforcing the maximum
+  const files: string[] = []
+  for (const p of paths) {
+    const stat = await fs.stat(p)
+    if (stat.isFile()) {
+      if (files.length >= MAX_SUBJECT_COUNT) {
+        throw new Error(
+          `Too many subjects specified (>${MAX_SUBJECT_COUNT}). The maximum number of subjects is ${MAX_SUBJECT_COUNT}.`
+        )
       }
-
-      const name = subjectName || path.parse(file).base
-      const digest = await digestFile(DIGEST_ALGORITHM, file)
-
-      subjects.push({ name, digest: { [DIGEST_ALGORITHM]: digest } })
+      files.push(p)
     }
   }
 
-  if (subjects.length === 0) {
+  for (const file of files) {
+    const name = subjectName || path.parse(file).base
+    const digest = await digestFile(DIGEST_ALGORITHM, file)
+
+    // Only add the subject if it is not already in the list
+    if (
+      !digestedSubjects.some(
+        s => s.name === name && s.digest[DIGEST_ALGORITHM] === digest
+      )
+    ) {
+      digestedSubjects.push({ name, digest: { [DIGEST_ALGORITHM]: digest } })
+    }
+  }
+
+  if (digestedSubjects.length === 0) {
     throw new Error(`Could not find subject at path ${subjectPath}`)
   }
 
-  return Promise.all(subjects)
+  return digestedSubjects
 }
 
 // Returns the subject specified by the digest of a file. The digest is returned
@@ -94,6 +148,78 @@ const getSubjectFromDigest = (
   }
 }
 
+const getSubjectFromChecksums = async (
+  subjectChecksums: string
+): Promise<Subject[]> => {
+  try {
+    await fs.access(subjectChecksums)
+    return getSubjectFromChecksumsFile(subjectChecksums)
+  } catch {
+    return getSubjectFromChecksumsString(subjectChecksums)
+  }
+}
+
+const getSubjectFromChecksumsFile = async (
+  checksumsPath: string
+): Promise<Subject[]> => {
+  const stats = await fs.stat(checksumsPath)
+  if (!stats.isFile()) {
+    throw new Error(`subject checksums file not found: ${checksumsPath}`)
+  }
+
+  /* istanbul ignore next */
+  if (stats.size > MAX_SUBJECT_CHECKSUM_SIZE_BYTES) {
+    throw new Error(
+      `subject checksums file exceeds maximum allowed size: ${MAX_SUBJECT_CHECKSUM_SIZE_BYTES} bytes`
+    )
+  }
+
+  const checksums = await fs.readFile(checksumsPath, 'utf-8')
+  return getSubjectFromChecksumsString(checksums)
+}
+
+const getSubjectFromChecksumsString = (checksums: string): Subject[] => {
+  const subjects: Subject[] = []
+
+  const records: string[] = checksums.split(os.EOL).filter(Boolean)
+
+  for (const record of records) {
+    // Find the space delimiter following the digest
+    const delimIndex = record.indexOf(' ')
+
+    // Skip any line that doesn't have a delimiter
+    if (delimIndex === -1) {
+      continue
+    }
+
+    // It's common for checksum records to have a leading flag character before
+    // the artifact name. It will be either a '*' or a space.
+    const flag_and_name = record.slice(delimIndex + 1)
+    const name =
+      flag_and_name.startsWith('*') || flag_and_name.startsWith(' ')
+        ? flag_and_name.slice(1)
+        : flag_and_name
+
+    const digest = record.slice(0, delimIndex)
+
+    if (!HEX_STRING_RE.test(digest)) {
+      throw new Error(`Invalid digest: ${digest}`)
+    }
+
+    const alg = digestAlgorithm(digest)
+
+    // Only add the subject if it is not already in the list (deduplicate by name & digest)
+    if (!subjects.some(s => s.name === name && s.digest[alg] === digest)) {
+      subjects.push({
+        name,
+        digest: { [alg]: digest }
+      })
+    }
+  }
+
+  return subjects
+}
+
 // Calculates the digest of a file using the specified algorithm. The file is
 // streamed into the digest function to avoid loading the entire file into
 // memory. The returned digest is a hex string.
@@ -103,14 +229,14 @@ const digestFile = async (
 ): Promise<string> => {
   return new Promise((resolve, reject) => {
     const hash = crypto.createHash(algorithm).setEncoding('hex')
-    fs.createReadStream(filePath)
+    createReadStream(filePath)
       .once('error', reject)
       .pipe(hash)
       .once('finish', () => resolve(hash.read()))
   })
 }
 
-const parseList = (input: string): string[] => {
+const parseSubjectPathList = (input: string): string[] => {
   const res: string[] = []
 
   const records: string[][] = parse(input, {
@@ -126,3 +252,14 @@ const parseList = (input: string): string[] => {
 
   return res.filter(item => item).map(pat => pat.trim())
 }
+
+const digestAlgorithm = (digest: string): string => {
+  switch (digest.length) {
+    case 64:
+      return 'sha256'
+    case 128:
+      return 'sha512'
+    default:
+      throw new Error(`Unknown digest algorithm: ${digest}`)
+  }
+}

tsconfig.json

@@ -2,9 +2,10 @@
   "$schema": "https://json.schemastore.org/tsconfig",
   "compilerOptions": {
     "target": "ES2022",
-    "module": "NodeNext",
+    "module": "ESNext",
     "rootDir": "./src",
-    "moduleResolution": "NodeNext",
+    "moduleResolution": "Bundler",
+    "isolatedModules": true,
     "baseUrl": "./",
     "sourceMap": true,
     "outDir": "./dist",

tsconfig.lint.json

@@ -0,0 +1,9 @@
+{
+  "$schema": "https://json.schemastore.org/tsconfig",
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "noEmit": true
+  },
+  "include": ["./__tests__/**/*", "./src/**/*"],
+  "exclude": ["./dist", "./node_modules", "./coverage", "*.json"]
+}