Index: node_modules/ssri/index.js
===================================================================
--- node_modules/ssri/index.js	(revision 81bc7da776d8cda42939ef4ab350c88d13b4941f)
+++ node_modules/ssri/index.js	(revision 81bc7da776d8cda42939ef4ab350c88d13b4941f)
@@ -0,0 +1,470 @@
+'use strict'
+
+const crypto = require('crypto')
+const MiniPass = require('minipass')
+
+const SPEC_ALGORITHMS = ['sha256', 'sha384', 'sha512']
+
+// TODO: this should really be a hardcoded list of algorithms we support,
+// rather than [a-z0-9].
+const BASE64_REGEX = /^[a-z0-9+/]+(?:=?=?)$/i
+const SRI_REGEX = /^([a-z0-9]+)-([^?]+)([?\S*]*)$/
+const STRICT_SRI_REGEX = /^([a-z0-9]+)-([A-Za-z0-9+/=]{44,88})(\?[\x21-\x7E]*)?$/
+const VCHAR_REGEX = /^[\x21-\x7E]+$/
+
+const defaultOpts = {
+  algorithms: ['sha512'],
+  error: false,
+  options: [],
+  pickAlgorithm: getPrioritizedHash,
+  sep: ' ',
+  single: false,
+  strict: false
+}
+
+const ssriOpts = (opts = {}) => ({ ...defaultOpts, ...opts })
+
+const getOptString = options => !options || !options.length
+  ? ''
+  : `?${options.join('?')}`
+
+const _onEnd = Symbol('_onEnd')
+const _getOptions = Symbol('_getOptions')
+class IntegrityStream extends MiniPass {
+  constructor (opts) {
+    super()
+    this.size = 0
+    this.opts = opts
+
+    // may be overridden later, but set now for class consistency
+    this[_getOptions]()
+
+    // options used for calculating stream.  can't be changed.
+    const { algorithms = defaultOpts.algorithms } = opts
+    this.algorithms = Array.from(
+      new Set(algorithms.concat(this.algorithm ? [this.algorithm] : []))
+    )
+    this.hashes = this.algorithms.map(crypto.createHash)
+  }
+
+  [_getOptions] () {
+    const {
+      integrity,
+      size,
+      options
+    } = { ...defaultOpts, ...this.opts }
+
+    // For verification
+    this.sri = integrity ? parse(integrity, this.opts) : null
+    this.expectedSize = size
+    this.goodSri = this.sri ? !!Object.keys(this.sri).length : false
+    this.algorithm = this.goodSri ? this.sri.pickAlgorithm(this.opts) : null
+    this.digests = this.goodSri ? this.sri[this.algorithm] : null
+    this.optString = getOptString(options)
+  }
+
+  emit (ev, data) {
+    if (ev === 'end') this[_onEnd]()
+    return super.emit(ev, data)
+  }
+
+  write (data) {
+    this.size += data.length
+    this.hashes.forEach(h => h.update(data))
+    return super.write(data)
+  }
+
+  [_onEnd] () {
+    if (!this.goodSri) {
+      this[_getOptions]()
+    }
+    const newSri = parse(this.hashes.map((h, i) => {
+      return `${this.algorithms[i]}-${h.digest('base64')}${this.optString}`
+    }).join(' '), this.opts)
+    // Integrity verification mode
+    const match = this.goodSri && newSri.match(this.sri, this.opts)
+    if (typeof this.expectedSize === 'number' && this.size !== this.expectedSize) {
+      const err = new Error(`stream size mismatch when checking ${this.sri}.\n  Wanted: ${this.expectedSize}\n  Found: ${this.size}`)
+      err.code = 'EBADSIZE'
+      err.found = this.size
+      err.expected = this.expectedSize
+      err.sri = this.sri
+      this.emit('error', err)
+    } else if (this.sri && !match) {
+      const err = new Error(`${this.sri} integrity checksum failed when using ${this.algorithm}: wanted ${this.digests} but got ${newSri}. (${this.size} bytes)`)
+      err.code = 'EINTEGRITY'
+      err.found = newSri
+      err.expected = this.digests
+      err.algorithm = this.algorithm
+      err.sri = this.sri
+      this.emit('error', err)
+    } else {
+      this.emit('size', this.size)
+      this.emit('integrity', newSri)
+      match && this.emit('verified', match)
+    }
+  }
+}
+
+class Hash {
+  get isHash () { return true }
+  constructor (hash, opts) {
+    opts = ssriOpts(opts)
+    const strict = !!opts.strict
+    this.source = hash.trim()
+
+    // set default values so that we make V8 happy to
+    // always see a familiar object template.
+    this.digest = ''
+    this.algorithm = ''
+    this.options = []
+
+    // 3.1. Integrity metadata (called "Hash" by ssri)
+    // https://w3c.github.io/webappsec-subresource-integrity/#integrity-metadata-description
+    const match = this.source.match(
+      strict
+        ? STRICT_SRI_REGEX
+        : SRI_REGEX
+    )
+    if (!match) { return }
+    if (strict && !SPEC_ALGORITHMS.some(a => a === match[1])) { return }
+    this.algorithm = match[1]
+    this.digest = match[2]
+
+    const rawOpts = match[3]
+    if (rawOpts) {
+      this.options = rawOpts.slice(1).split('?')
+    }
+  }
+
+  hexDigest () {
+    return this.digest && Buffer.from(this.digest, 'base64').toString('hex')
+  }
+
+  toJSON () {
+    return this.toString()
+  }
+
+  toString (opts) {
+    opts = ssriOpts(opts)
+    if (opts.strict) {
+      // Strict mode enforces the standard as close to the foot of the
+      // letter as it can.
+      if (!(
+        // The spec has very restricted productions for algorithms.
+        // https://www.w3.org/TR/CSP2/#source-list-syntax
+        SPEC_ALGORITHMS.some(x => x === this.algorithm) &&
+        // Usually, if someone insists on using a "different" base64, we
+        // leave it as-is, since there's multiple standards, and the
+        // specified is not a URL-safe variant.
+        // https://www.w3.org/TR/CSP2/#base64_value
+        this.digest.match(BASE64_REGEX) &&
+        // Option syntax is strictly visual chars.
+        // https://w3c.github.io/webappsec-subresource-integrity/#grammardef-option-expression
+        // https://tools.ietf.org/html/rfc5234#appendix-B.1
+        this.options.every(opt => opt.match(VCHAR_REGEX))
+      )) {
+        return ''
+      }
+    }
+    const options = this.options && this.options.length
+      ? `?${this.options.join('?')}`
+      : ''
+    return `${this.algorithm}-${this.digest}${options}`
+  }
+}
+
+class Integrity {
+  get isIntegrity () { return true }
+  toJSON () {
+    return this.toString()
+  }
+
+  isEmpty () {
+    return Object.keys(this).length === 0
+  }
+
+  toString (opts) {
+    opts = ssriOpts(opts)
+    let sep = opts.sep || ' '
+    if (opts.strict) {
+      // Entries must be separated by whitespace, according to spec.
+      sep = sep.replace(/\S+/g, ' ')
+    }
+    return Object.keys(this).map(k => {
+      return this[k].map(hash => {
+        return Hash.prototype.toString.call(hash, opts)
+      }).filter(x => x.length).join(sep)
+    }).filter(x => x.length).join(sep)
+  }
+
+  concat (integrity, opts) {
+    opts = ssriOpts(opts)
+    const other = typeof integrity === 'string'
+      ? integrity
+      : stringify(integrity, opts)
+    return parse(`${this.toString(opts)} ${other}`, opts)
+  }
+
+  hexDigest () {
+    return parse(this, { single: true }).hexDigest()
+  }
+
+  // add additional hashes to an integrity value, but prevent
+  // *changing* an existing integrity hash.
+  merge (integrity, opts) {
+    opts = ssriOpts(opts)
+    const other = parse(integrity, opts)
+    for (const algo in other) {
+      if (this[algo]) {
+        if (!this[algo].find(hash =>
+          other[algo].find(otherhash =>
+            hash.digest === otherhash.digest))) {
+          throw new Error('hashes do not match, cannot update integrity')
+        }
+      } else {
+        this[algo] = other[algo]
+      }
+    }
+  }
+
+  match (integrity, opts) {
+    opts = ssriOpts(opts)
+    const other = parse(integrity, opts)
+    const algo = other.pickAlgorithm(opts)
+    return (
+      this[algo] &&
+      other[algo] &&
+      this[algo].find(hash =>
+        other[algo].find(otherhash =>
+          hash.digest === otherhash.digest
+        )
+      )
+    ) || false
+  }
+
+  pickAlgorithm (opts) {
+    opts = ssriOpts(opts)
+    const pickAlgorithm = opts.pickAlgorithm
+    const keys = Object.keys(this)
+    return keys.reduce((acc, algo) => {
+      return pickAlgorithm(acc, algo) || acc
+    })
+  }
+}
+
+module.exports.parse = parse
+function parse (sri, opts) {
+  if (!sri) return null
+  opts = ssriOpts(opts)
+  if (typeof sri === 'string') {
+    return _parse(sri, opts)
+  } else if (sri.algorithm && sri.digest) {
+    const fullSri = new Integrity()
+    fullSri[sri.algorithm] = [sri]
+    return _parse(stringify(fullSri, opts), opts)
+  } else {
+    return _parse(stringify(sri, opts), opts)
+  }
+}
+
+function _parse (integrity, opts) {
+  // 3.4.3. Parse metadata
+  // https://w3c.github.io/webappsec-subresource-integrity/#parse-metadata
+  if (opts.single) {
+    return new Hash(integrity, opts)
+  }
+  const hashes = integrity.trim().split(/\s+/).reduce((acc, string) => {
+    const hash = new Hash(string, opts)
+    if (hash.algorithm && hash.digest) {
+      const algo = hash.algorithm
+      if (!acc[algo]) { acc[algo] = [] }
+      acc[algo].push(hash)
+    }
+    return acc
+  }, new Integrity())
+  return hashes.isEmpty() ? null : hashes
+}
+
+module.exports.stringify = stringify
+function stringify (obj, opts) {
+  opts = ssriOpts(opts)
+  if (obj.algorithm && obj.digest) {
+    return Hash.prototype.toString.call(obj, opts)
+  } else if (typeof obj === 'string') {
+    return stringify(parse(obj, opts), opts)
+  } else {
+    return Integrity.prototype.toString.call(obj, opts)
+  }
+}
+
+module.exports.fromHex = fromHex
+function fromHex (hexDigest, algorithm, opts) {
+  opts = ssriOpts(opts)
+  const optString = getOptString(opts.options)
+  return parse(
+    `${algorithm}-${
+      Buffer.from(hexDigest, 'hex').toString('base64')
+    }${optString}`, opts
+  )
+}
+
+module.exports.fromData = fromData
+function fromData (data, opts) {
+  opts = ssriOpts(opts)
+  const algorithms = opts.algorithms
+  const optString = getOptString(opts.options)
+  return algorithms.reduce((acc, algo) => {
+    const digest = crypto.createHash(algo).update(data).digest('base64')
+    const hash = new Hash(
+      `${algo}-${digest}${optString}`,
+      opts
+    )
+    /* istanbul ignore else - it would be VERY strange if the string we
+     * just calculated with an algo did not have an algo or digest.
+     */
+    if (hash.algorithm && hash.digest) {
+      const algo = hash.algorithm
+      if (!acc[algo]) { acc[algo] = [] }
+      acc[algo].push(hash)
+    }
+    return acc
+  }, new Integrity())
+}
+
+module.exports.fromStream = fromStream
+function fromStream (stream, opts) {
+  opts = ssriOpts(opts)
+  const istream = integrityStream(opts)
+  return new Promise((resolve, reject) => {
+    stream.pipe(istream)
+    stream.on('error', reject)
+    istream.on('error', reject)
+    let sri
+    istream.on('integrity', s => { sri = s })
+    istream.on('end', () => resolve(sri))
+    istream.on('data', () => {})
+  })
+}
+
+module.exports.checkData = checkData
+function checkData (data, sri, opts) {
+  opts = ssriOpts(opts)
+  sri = parse(sri, opts)
+  if (!sri || !Object.keys(sri).length) {
+    if (opts.error) {
+      throw Object.assign(
+        new Error('No valid integrity hashes to check against'), {
+          code: 'EINTEGRITY'
+        }
+      )
+    } else {
+      return false
+    }
+  }
+  const algorithm = sri.pickAlgorithm(opts)
+  const digest = crypto.createHash(algorithm).update(data).digest('base64')
+  const newSri = parse({ algorithm, digest })
+  const match = newSri.match(sri, opts)
+  if (match || !opts.error) {
+    return match
+  } else if (typeof opts.size === 'number' && (data.length !== opts.size)) {
+    const err = new Error(`data size mismatch when checking ${sri}.\n  Wanted: ${opts.size}\n  Found: ${data.length}`)
+    err.code = 'EBADSIZE'
+    err.found = data.length
+    err.expected = opts.size
+    err.sri = sri
+    throw err
+  } else {
+    const err = new Error(`Integrity checksum failed when using ${algorithm}: Wanted ${sri}, but got ${newSri}. (${data.length} bytes)`)
+    err.code = 'EINTEGRITY'
+    err.found = newSri
+    err.expected = sri
+    err.algorithm = algorithm
+    err.sri = sri
+    throw err
+  }
+}
+
+module.exports.checkStream = checkStream
+function checkStream (stream, sri, opts) {
+  opts = ssriOpts(opts)
+  opts.integrity = sri
+  sri = parse(sri, opts)
+  if (!sri || !Object.keys(sri).length) {
+    return Promise.reject(Object.assign(
+      new Error('No valid integrity hashes to check against'), {
+        code: 'EINTEGRITY'
+      }
+    ))
+  }
+  const checker = integrityStream(opts)
+  return new Promise((resolve, reject) => {
+    stream.pipe(checker)
+    stream.on('error', reject)
+    checker.on('error', reject)
+    let sri
+    checker.on('verified', s => { sri = s })
+    checker.on('end', () => resolve(sri))
+    checker.on('data', () => {})
+  })
+}
+
+module.exports.integrityStream = integrityStream
+function integrityStream (opts = {}) {
+  return new IntegrityStream(opts)
+}
+
+module.exports.create = createIntegrity
+function createIntegrity (opts) {
+  opts = ssriOpts(opts)
+  const algorithms = opts.algorithms
+  const optString = getOptString(opts.options)
+
+  const hashes = algorithms.map(crypto.createHash)
+
+  return {
+    update: function (chunk, enc) {
+      hashes.forEach(h => h.update(chunk, enc))
+      return this
+    },
+    digest: function (enc) {
+      const integrity = algorithms.reduce((acc, algo) => {
+        const digest = hashes.shift().digest('base64')
+        const hash = new Hash(
+          `${algo}-${digest}${optString}`,
+          opts
+        )
+        /* istanbul ignore else - it would be VERY strange if the hash we
+         * just calculated with an algo did not have an algo or digest.
+         */
+        if (hash.algorithm && hash.digest) {
+          const algo = hash.algorithm
+          if (!acc[algo]) { acc[algo] = [] }
+          acc[algo].push(hash)
+        }
+        return acc
+      }, new Integrity())
+
+      return integrity
+    }
+  }
+}
+
+const NODE_HASHES = new Set(crypto.getHashes())
+
+// This is a Best Effort™ at a reasonable priority for hash algos
+const DEFAULT_PRIORITY = [
+  'md5', 'whirlpool', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512',
+  // TODO - it's unclear _which_ of these Node will actually use as its name
+  //        for the algorithm, so we guesswork it based on the OpenSSL names.
+  'sha3',
+  'sha3-256', 'sha3-384', 'sha3-512',
+  'sha3_256', 'sha3_384', 'sha3_512'
+].filter(algo => NODE_HASHES.has(algo))
+
+function getPrioritizedHash (algo1, algo2) {
+  return DEFAULT_PRIORITY.indexOf(algo1.toLowerCase()) >= DEFAULT_PRIORITY.indexOf(algo2.toLowerCase())
+    ? algo1
+    : algo2
+}