sigstore-js ·

A JavaScript library for generating and verifying Sigstore signatures. One of the intended uses is to sign and verify npm packages but it can be used to sign and verify any file.

Features

Support for signing using an OpenID Connect identity
Support for publishing signatures to a Rekor instance
Support for verifying Sigstore bundles

Prerequisites

Node.js version >= 14.17.0

Installation

npm install sigstore

Usage

const { sigstore } = require('sigstore')

import { sigstore } from 'sigstore'

sign(payload[, options])

Generates a Sigstore signature for the supplied payload. Returns a Sigstore bundle containing the signature and the verification material necessary to verify the signature.

payload <Buffer>: The bytes of the artifact to be signed.
options <Object>
- fulcioURL <string>: The base URL of the Fulcio instance to use for retrieving the signing certificate. Defaults to 'https://fulcio.sigstore.dev'.
- rekorURL <string>: The base URL of the Rekor instance to use when adding the signature to the transparency log. Defaults to 'https://rekor.sigstore.dev'.
- identityToken <string>: The OIDC token identifying the signer. If no explicit token is supplied, an attempt will be made to retrieve one from the environment.

attest(payload, payloadType[, options])

Generates a Sigstore signature for the supplied in-toto statement. Returns a Sigstore bundle containing the DSSE-wrapped statement and signature as well as the verification material necessary to verify the signature.

payload <Buffer>: The bytes of the statement to be signed.
payloadType <string>: MIME or content type describing the statement to be signed.
options <Object>
- fulcioURL <string>: The base URL of the Fulcio instance to use for retrieving the signing certificate. Defaults to 'https://fulcio.sigstore.dev'.
- rekorURL <string>: The base URL of the Rekor instance to use when adding the signature to the transparency log. Defaults to 'https://rekor.sigstore.dev'.
- identityToken <string>: The OIDC token identifying the signer. If no explicit token is supplied, an attempt will be made to retrieve one from the environment.

verify(bundle[, payload][, options])

Verifies the signature in the supplied bundle.

bundle <Bundle>: The Sigstore bundle containing the signature to be verified and the verification material necessary to verify the signature.
payload <Buffer>: The bytes of the artifact over which the signature was created. Only necessary when the sign function was used to generate the signature since the Bundle does not contain any information about the artifact which was signed. Not required when the attest function was used to generate the Bundle.
options <Object>
- ctLogThreshold <number>: The number of certificate transparency logs on which the signing certificate must appear. Defaults to 1.
- tlogThreshold <number>: The number of transparency logs on which the signature must appear. Defaults to 1.
- certificateIssuer <string>: Value that must appear in the signing certificate's issuer extension (OID 1.3.6.1.4.1.57264.1.1). Not verified if no value is supplied.
- certificateIdentityEmail <string>: Email address which must appear in the signing certificate's Subject Alternative Name (SAN) extension. Must be specified in conjunction with the certificateIssuer option. Takes precedence over the certificateIdentityURI option. Not verified if no value is supplied.
- certificateIdentityURI <string>: URI which must appear in the signing certificate's Subject Alternative Name (SAN) extension. Must be specified in conjunction with the certificateIssuer option. Ignored if the certificateIdentityEmail option is set. Not verified if no value is supplied.
- certificateOIDs <Object>: A collection of OID/value pairs which must be present in the certificate's extension list. Not verified if no value is supplied.
- keySelector <Function>: Callback invoked to retrieve the public key (as either string or Buffer) necessary to verify the bundle signature. Not used when the signature was generated from a Fulcio-issued signing certificate.
  - hint <String>: The hint from the bundle used to identify the the signing key.

tuf

The tuf object contains utility function for working with the Sigstore TUF repository.

getTarget(path[, options])

Returns the contents of the target at the specified path in the Sigstore TUF repository.

path <string>: The path-relative-url string that uniquely identifies the target within the Sigstore TUF repository.
options <Object>
- tufMirrorURL <string>: Base URL for the Sigstore TUF repository. Defaults to 'https://tuf-repo-cdn.sigstore.dev'
- tufRootPath <string>: Path to the initial trusted root for the TUF repository. Defaults to the embedded root.
- tufCachePath <string>: Absolute path to the directory to be used for caching downloaded TUF metadata and targets. Defaults to a directory named "sigstore-js" within the platform-specific application data directory.

utils

The utils object contains a few internal utility functions. These are exposed to support the needs of specific sigstore-js consumers but should NOT be considered part of the stable public interface.

CLI

The sigstore-js library comes packaged with a basic command line interface for testing and demo purposes. However, the CLI should NOT be considered part of the stable interface of the library. If you require a production-ready Sigstore CLI, we recommend you use cosign.

$ npx sigstore help
sigstore <command> <artifact>

  Usage:

  sigstore sign         sign an artifact
  sigstore attest       sign an artifact using dsse (Dead Simple Signing Envelope)
  sigstore verify       verify an artifact
  sigstore version      print version information
  sigstore help         print help information

Credential Sources

GitHub Actions

If sigstore-js detects that it is being executed on GitHub Actions, it will use ACTIONS_ID_TOKEN_REQUEST_URL and ACTIONS_ID_TOKEN_REQUEST_TOKEN environment variables to request an OIDC token with the correct scope.

Note: the id_token: write permission must be granted to the GitHub Action Job.

See https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/about-security-hardening-with-openid-connect for more details.

Environment Variables

If the SIGSTORE_ID_TOKEN environment variable is set, it will use this to authenticate to Fulcio. It is the callers responsibility to make sure that this token has the correct scopes.

Interactive Flow

If sigstore-js cannot detect ambient credentials, then it will prompt the user to go through the interactive flow.

Development

Changesets

If you are contributing a user-facing or noteworthy change that should be added to the changelog, you should include a changeset with your PR by running the following command:

npx changeset add

Follow the prompts to specify whether the change is a major, minor or patch change. This will create a file in the .changesets directory of the repo. This change should be committed and included with your PR.

Updating Rekor Types

Update the git REF in hack/generate-rekor-types from the sigstore/rekor repository.

Generate TypeScript types (should update files in scr/types/rekor/__generated__):

npm run codegen:rekor

Release Steps

Whenever a new changeset is merged to the "main" branch, the release workflow will open a PR (or append to the existing PR if one is already open) with the all of the pending changesets.

Publishing a release simply requires that you approve/merge this PR. This will trigger the publishing of the package to the npm registry and the creation of the GitHub release.

Licensing

sigstore-js is licensed under the Apache 2.0 License.

Contributing

See the contributing docs for details.

Code of Conduct

Everyone interacting with this project is expected to follow the sigstore Code of Conduct.

Security

Should you discover any security issues, please refer to sigstore's security process.

Info

sigstore-js is developed as part of the sigstore project.

We also use a slack channel! Click here for the invite link.

ianlewis / sigstore-js