ssri 12.0.0

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:npm/ssri@12.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/ssri@12.0.0

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:11339be619f8a9ca4f74323632c75d7b2d6be51156134de46fe3b2a8570add43","contract":["ssri.fromData generates Integrity metadata for specified algorithms and options","ssri.stringify and ssri.parse round-trip multi-algorithm and single-hash SRI strings","ssri.fromHex and Hash.hexDigest convert between hex digests and SRI Hash objects","ssri.checkData returns matching Hash on valid data, false on mismatch by default, and throws EINTEGRITY or EBADSIZE when error: true","ssri.create computes incremental Integrity digests and supports concat and merge","ssri.fromStream, ssri.checkStream, and ssri.integrityStream generate and verify integrity metadata over streams"],"goal":"verify pkg:npm/ssri@12.0.0","kind":"HOW","packages":["pkg:npm/ssri@12.0.0"],"schemaVersion":1},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/ssri@12.0.0"],"schemaVersion":1,"subject":"pkg:npm/ssri@12.0.0","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-ssri",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-ssri",
      "version": "1.0.0",
      "dependencies": {
        "ssri": "12.0.0"
      }
    },
    "node_modules/minipass": {
      "version": "7.1.3",
      "resolved": "https://registry.npmjs.org/minipass/-/minipass-7.1.3.tgz",
      "integrity": "sha512-tEBHqDnIoM/1rXME1zgka9g6Q2lcoCkxHLuc7ODJ5BxbP5d4c2Z5cGgtXAku59200Cx7diuHTOYfSBD8n6mm8A==",
      "license": "BlueOak-1.0.0",
      "engines": {
        "node": ">=16 || 14 >=14.17"
      }
    },
    "node_modules/ssri": {
      "version": "12.0.0",
      "resolved": "https://registry.npmjs.org/ssri/-/ssri-12.0.0.tgz",
      "integrity": "sha512-S7iGNosepx9RadX82oimUkvr0Ct7IjJbEbs4mJcTxst8um95J3sDYU1RBEOvdu6oL1Wek2ODI5i4MAw+dZ6cAQ==",
      "license": "ISC",
      "dependencies": {
        "minipass": "^7.0.3"
      },
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    }
  }
}

{
  "name": "sample-ssri",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "ssri": "12.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/ssri@12.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/ssri@12.0.0"
  ]
}

import assert from 'node:assert/strict'
import { Readable } from 'node:stream'
import * as ssri from 'ssri'

const payload = Buffer.from('hello subresource integrity')

// 1. fromData & stringify & parse
const integrity = ssri.fromData(payload, {
  algorithms: ['sha256', 'sha512'],
  options: ['opt1'],
})
assert.equal(integrity.isIntegrity, true)
assert.equal(integrity.isEmpty(), false)
assert.equal(integrity.pickAlgorithm(), 'sha512')

const sriString = ssri.stringify(integrity)
assert.match(sriString, /^sha256-[A-Za-z0-9+/=]+\?opt1 sha512-[A-Za-z0-9+/=]+\?opt1$/)

const parsed = ssri.parse(sriString)
assert.equal(parsed.toString(), sriString)
assert.ok(parsed.match(integrity))

// 2. single hash parse, hexDigest, fromHex
const singleHash = ssri.parse(parsed.sha256[0].toString(), { single: true })
assert.equal(singleHash.isHash, true)
assert.equal(singleHash.algorithm, 'sha256')
assert.deepEqual(singleHash.options, ['opt1'])

const hex = singleHash.hexDigest()
assert.match(hex, /^[0-9a-f]{64}$/)
const fromHexSri = ssri.fromHex(hex, 'sha256', { single: true, options: ['opt1'] })
assert.equal(fromHexSri.toString(), singleHash.toString())

// 3. checkData success and error modes (EINTEGRITY, EBADSIZE)
const matchedHash = ssri.checkData(payload, sriString)
assert.equal(matchedHash.algorithm, 'sha512')
assert.equal(ssri.checkData('wrong data', sriString), false)

assert.throws(
  () => ssri.checkData(Buffer.from('wrong'), sriString, { error: true }),
  { code: 'EINTEGRITY' }
)
assert.throws(
  () => ssri.checkData(Buffer.from('wrong'), sriString, { error: true, size: payload.length }),
  { code: 'EBADSIZE', expected: payload.length, found: 5 }
)

// 4. create (incremental hashing) & concat / merge
const builder = ssri.create({ algorithms: ['sha256'] })
builder.update('hello ')
builder.update('subresource integrity')
const created = builder.digest()
assert.equal(created.sha256[0].digest, integrity.sha256[0].digest)

const sha384Only = ssri.fromData(payload, { algorithms: ['sha384'] })
const concatenated = created.concat(sha384Only)
assert.ok(concatenated.sha256)
assert.ok(concatenated.sha384)

created.merge(sha384Only)
assert.ok(created.sha384)

// 5. fromStream, checkStream, integrityStream
const streamSri = await ssri.fromStream(Readable.from([payload]), {
  algorithms: ['sha512'],
})
assert.equal(streamSri.toString(), integrity.sha512[0].toString().replace('?opt1', ''))

const verifiedStreamHash = await ssri.checkStream(
  Readable.from([payload]),
  streamSri,
  { size: payload.length }
)
assert.equal(verifiedStreamHash.algorithm, 'sha512')

await assert.rejects(
  ssri.checkStream(Readable.from([Buffer.from('bad')]), streamSri),
  { code: 'EINTEGRITY' }
)

const istream = ssri.integrityStream({ integrity: streamSri, size: payload.length })
let emittedSize = 0
istream.on('size', s => {
  emittedSize = s
})
istream.end(payload)
await new Promise((resolve, reject) => {
  istream.on('end', resolve)
  istream.on('error', reject)
  istream.resume()
})
assert.equal(emittedSize, payload.length)