Adding upstream version 5.28.2+dfsg1+~cs23.11.12.3.upstream/5.28.2+dfsg1+_cs23.11.12.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1071 insertions, 0 deletions

diff --git a/lib/fetch/util.js b/lib/fetch/util.js
new file mode 100644
index 0000000..b12142c
--- /dev/null
+++ b/lib/fetch/util.js
@@ -0,0 +1,1071 @@
+'use strict'
+
+const { redirectStatusSet, referrerPolicySet: referrerPolicyTokens, badPortsSet } = require('./constants')
+const { getGlobalOrigin } = require('./global')
+const { performance } = require('perf_hooks')
+const { isBlobLike, toUSVString, ReadableStreamFrom } = require('../core/util')
+const assert = require('assert')
+const { isUint8Array } = require('util/types')
+
+// https://nodejs.org/api/crypto.html#determining-if-crypto-support-is-unavailable
+/** @type {import('crypto')|undefined} */
+let crypto
+
+try {
+  crypto = require('crypto')
+} catch {
+
+}
+
+function responseURL (response) {
+  // https://fetch.spec.whatwg.org/#responses
+  // A response has an associated URL. It is a pointer to the last URL
+  // in response’s URL list and null if response’s URL list is empty.
+  const urlList = response.urlList
+  const length = urlList.length
+  return length === 0 ? null : urlList[length - 1].toString()
+}
+
+// https://fetch.spec.whatwg.org/#concept-response-location-url
+function responseLocationURL (response, requestFragment) {
+  // 1. If response’s status is not a redirect status, then return null.
+  if (!redirectStatusSet.has(response.status)) {
+    return null
+  }
+
+  // 2. Let location be the result of extracting header list values given
+  // `Location` and response’s header list.
+  let location = response.headersList.get('location')
+
+  // 3. If location is a header value, then set location to the result of
+  //    parsing location with response’s URL.
+  if (location !== null && isValidHeaderValue(location)) {
+    location = new URL(location, responseURL(response))
+  }
+
+  // 4. If location is a URL whose fragment is null, then set location’s
+  // fragment to requestFragment.
+  if (location && !location.hash) {
+    location.hash = requestFragment
+  }
+
+  // 5. Return location.
+  return location
+}
+
+/** @returns {URL} */
+function requestCurrentURL (request) {
+  return request.urlList[request.urlList.length - 1]
+}
+
+function requestBadPort (request) {
+  // 1. Let url be request’s current URL.
+  const url = requestCurrentURL(request)
+
+  // 2. If url’s scheme is an HTTP(S) scheme and url’s port is a bad port,
+  // then return blocked.
+  if (urlIsHttpHttpsScheme(url) && badPortsSet.has(url.port)) {
+    return 'blocked'
+  }
+
+  // 3. Return allowed.
+  return 'allowed'
+}
+
+function isErrorLike (object) {
+  return object instanceof Error || (
+    object?.constructor?.name === 'Error' ||
+    object?.constructor?.name === 'DOMException'
+  )
+}
+
+// Check whether |statusText| is a ByteString and
+// matches the Reason-Phrase token production.
+// RFC 2616: https://tools.ietf.org/html/rfc2616
+// RFC 7230: https://tools.ietf.org/html/rfc7230
+// "reason-phrase = *( HTAB / SP / VCHAR / obs-text )"
+// https://github.com/chromium/chromium/blob/94.0.4604.1/third_party/blink/renderer/core/fetch/response.cc#L116
+function isValidReasonPhrase (statusText) {
+  for (let i = 0; i < statusText.length; ++i) {
+    const c = statusText.charCodeAt(i)
+    if (
+      !(
+        (
+          c === 0x09 || // HTAB
+          (c >= 0x20 && c <= 0x7e) || // SP / VCHAR
+          (c >= 0x80 && c <= 0xff)
+        ) // obs-text
+      )
+    ) {
+      return false
+    }
+  }
+  return true
+}
+
+/**
+ * @see https://tools.ietf.org/html/rfc7230#section-3.2.6
+ * @param {number} c
+ */
+function isTokenCharCode (c) {
+  switch (c) {
+    case 0x22:
+    case 0x28:
+    case 0x29:
+    case 0x2c:
+    case 0x2f:
+    case 0x3a:
+    case 0x3b:
+    case 0x3c:
+    case 0x3d:
+    case 0x3e:
+    case 0x3f:
+    case 0x40:
+    case 0x5b:
+    case 0x5c:
+    case 0x5d:
+    case 0x7b:
+    case 0x7d:
+      // DQUOTE and "(),/:;<=>?@[\]{}"
+      return false
+    default:
+      // VCHAR %x21-7E
+      return c >= 0x21 && c <= 0x7e
+  }
+}
+
+/**
+ * @param {string} characters
+ */
+function isValidHTTPToken (characters) {
+  if (characters.length === 0) {
+    return false
+  }
+  for (let i = 0; i < characters.length; ++i) {
+    if (!isTokenCharCode(characters.charCodeAt(i))) {
+      return false
+    }
+  }
+  return true
+}
+
+/**
+ * @see https://fetch.spec.whatwg.org/#header-name
+ * @param {string} potentialValue
+ */
+function isValidHeaderName (potentialValue) {
+  return isValidHTTPToken(potentialValue)
+}
+
+/**
+ * @see https://fetch.spec.whatwg.org/#header-value
+ * @param {string} potentialValue
+ */
+function isValidHeaderValue (potentialValue) {
+  // - Has no leading or trailing HTTP tab or space bytes.
+  // - Contains no 0x00 (NUL) or HTTP newline bytes.
+  if (
+    potentialValue.startsWith('\t') ||
+    potentialValue.startsWith(' ') ||
+    potentialValue.endsWith('\t') ||
+    potentialValue.endsWith(' ')
+  ) {
+    return false
+  }
+
+  if (
+    potentialValue.includes('\0') ||
+    potentialValue.includes('\r') ||
+    potentialValue.includes('\n')
+  ) {
+    return false
+  }
+
+  return true
+}
+
+// https://w3c.github.io/webappsec-referrer-policy/#set-requests-referrer-policy-on-redirect
+function setRequestReferrerPolicyOnRedirect (request, actualResponse) {
+  //  Given a request request and a response actualResponse, this algorithm
+  //  updates request’s referrer policy according to the Referrer-Policy
+  //  header (if any) in actualResponse.
+
+  // 1. Let policy be the result of executing § 8.1 Parse a referrer policy
+  // from a Referrer-Policy header on actualResponse.
+
+  // 8.1 Parse a referrer policy from a Referrer-Policy header
+  // 1. Let policy-tokens be the result of extracting header list values given `Referrer-Policy` and response’s header list.
+  const { headersList } = actualResponse
+  // 2. Let policy be the empty string.
+  // 3. For each token in policy-tokens, if token is a referrer policy and token is not the empty string, then set policy to token.
+  // 4. Return policy.
+  const policyHeader = (headersList.get('referrer-policy') ?? '').split(',')
+
+  // Note: As the referrer-policy can contain multiple policies
+  // separated by comma, we need to loop through all of them
+  // and pick the first valid one.
+  // Ref: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy#specify_a_fallback_policy
+  let policy = ''
+  if (policyHeader.length > 0) {
+    // The right-most policy takes precedence.
+    // The left-most policy is the fallback.
+    for (let i = policyHeader.length; i !== 0; i--) {
+      const token = policyHeader[i - 1].trim()
+      if (referrerPolicyTokens.has(token)) {
+        policy = token
+        break
+      }
+    }
+  }
+
+  // 2. If policy is not the empty string, then set request’s referrer policy to policy.
+  if (policy !== '') {
+    request.referrerPolicy = policy
+  }
+}
+
+// https://fetch.spec.whatwg.org/#cross-origin-resource-policy-check
+function crossOriginResourcePolicyCheck () {
+  // TODO
+  return 'allowed'
+}
+
+// https://fetch.spec.whatwg.org/#concept-cors-check
+function corsCheck () {
+  // TODO
+  return 'success'
+}
+
+// https://fetch.spec.whatwg.org/#concept-tao-check
+function TAOCheck () {
+  // TODO
+  return 'success'
+}
+
+function appendFetchMetadata (httpRequest) {
+  //  https://w3c.github.io/webappsec-fetch-metadata/#sec-fetch-dest-header
+  //  TODO
+
+  //  https://w3c.github.io/webappsec-fetch-metadata/#sec-fetch-mode-header
+
+  //  1. Assert: r’s url is a potentially trustworthy URL.
+  //  TODO
+
+  //  2. Let header be a Structured Header whose value is a token.
+  let header = null
+
+  //  3. Set header’s value to r’s mode.
+  header = httpRequest.mode
+
+  //  4. Set a structured field value `Sec-Fetch-Mode`/header in r’s header list.
+  httpRequest.headersList.set('sec-fetch-mode', header)
+
+  //  https://w3c.github.io/webappsec-fetch-metadata/#sec-fetch-site-header
+  //  TODO
+
+  //  https://w3c.github.io/webappsec-fetch-metadata/#sec-fetch-user-header
+  //  TODO
+}
+
+// https://fetch.spec.whatwg.org/#append-a-request-origin-header
+function appendRequestOriginHeader (request) {
+  // 1. Let serializedOrigin be the result of byte-serializing a request origin with request.
+  let serializedOrigin = request.origin
+
+  // 2. If request’s response tainting is "cors" or request’s mode is "websocket", then append (`Origin`, serializedOrigin) to request’s header list.
+  if (request.responseTainting === 'cors' || request.mode === 'websocket') {
+    if (serializedOrigin) {
+      request.headersList.append('origin', serializedOrigin)
+    }
+
+  // 3. Otherwise, if request’s method is neither `GET` nor `HEAD`, then:
+  } else if (request.method !== 'GET' && request.method !== 'HEAD') {
+    // 1. Switch on request’s referrer policy:
+    switch (request.referrerPolicy) {
+      case 'no-referrer':
+        // Set serializedOrigin to `null`.
+        serializedOrigin = null
+        break
+      case 'no-referrer-when-downgrade':
+      case 'strict-origin':
+      case 'strict-origin-when-cross-origin':
+        // If request’s origin is a tuple origin, its scheme is "https", and request’s current URL’s scheme is not "https", then set serializedOrigin to `null`.
+        if (request.origin && urlHasHttpsScheme(request.origin) && !urlHasHttpsScheme(requestCurrentURL(request))) {
+          serializedOrigin = null
+        }
+        break
+      case 'same-origin':
+        // If request’s origin is not same origin with request’s current URL’s origin, then set serializedOrigin to `null`.
+        if (!sameOrigin(request, requestCurrentURL(request))) {
+          serializedOrigin = null
+        }
+        break
+      default:
+        // Do nothing.
+    }
+
+    if (serializedOrigin) {
+      // 2. Append (`Origin`, serializedOrigin) to request’s header list.
+      request.headersList.append('origin', serializedOrigin)
+    }
+  }
+}
+
+function coarsenedSharedCurrentTime (crossOriginIsolatedCapability) {
+  // TODO
+  return performance.now()
+}
+
+// https://fetch.spec.whatwg.org/#create-an-opaque-timing-info
+function createOpaqueTimingInfo (timingInfo) {
+  return {
+    startTime: timingInfo.startTime ?? 0,
+    redirectStartTime: 0,
+    redirectEndTime: 0,
+    postRedirectStartTime: timingInfo.startTime ?? 0,
+    finalServiceWorkerStartTime: 0,
+    finalNetworkResponseStartTime: 0,
+    finalNetworkRequestStartTime: 0,
+    endTime: 0,
+    encodedBodySize: 0,
+    decodedBodySize: 0,
+    finalConnectionTimingInfo: null
+  }
+}
+
+// https://html.spec.whatwg.org/multipage/origin.html#policy-container
+function makePolicyContainer () {
+  // Note: the fetch spec doesn't make use of embedder policy or CSP list
+  return {
+    referrerPolicy: 'strict-origin-when-cross-origin'
+  }
+}
+
+// https://html.spec.whatwg.org/multipage/origin.html#clone-a-policy-container
+function clonePolicyContainer (policyContainer) {
+  return {
+    referrerPolicy: policyContainer.referrerPolicy
+  }
+}
+
+// https://w3c.github.io/webappsec-referrer-policy/#determine-requests-referrer
+function determineRequestsReferrer (request) {
+  // 1. Let policy be request's referrer policy.
+  const policy = request.referrerPolicy
+
+  // Note: policy cannot (shouldn't) be null or an empty string.
+  assert(policy)
+
+  // 2. Let environment be request’s client.
+
+  let referrerSource = null
+
+  // 3. Switch on request’s referrer:
+  if (request.referrer === 'client') {
+    // Note: node isn't a browser and doesn't implement document/iframes,
+    // so we bypass this step and replace it with our own.
+
+    const globalOrigin = getGlobalOrigin()
+
+    if (!globalOrigin || globalOrigin.origin === 'null') {
+      return 'no-referrer'
+    }
+
+    // note: we need to clone it as it's mutated
+    referrerSource = new URL(globalOrigin)
+  } else if (request.referrer instanceof URL) {
+    // Let referrerSource be request’s referrer.
+    referrerSource = request.referrer
+  }
+
+  // 4. Let request’s referrerURL be the result of stripping referrerSource for
+  //    use as a referrer.
+  let referrerURL = stripURLForReferrer(referrerSource)
+
+  // 5. Let referrerOrigin be the result of stripping referrerSource for use as
+  //    a referrer, with the origin-only flag set to true.
+  const referrerOrigin = stripURLForReferrer(referrerSource, true)
+
+  // 6. If the result of serializing referrerURL is a string whose length is
+  //    greater than 4096, set referrerURL to referrerOrigin.
+  if (referrerURL.toString().length > 4096) {
+    referrerURL = referrerOrigin
+  }
+
+  const areSameOrigin = sameOrigin(request, referrerURL)
+  const isNonPotentiallyTrustWorthy = isURLPotentiallyTrustworthy(referrerURL) &&
+    !isURLPotentiallyTrustworthy(request.url)
+
+  // 8. Execute the switch statements corresponding to the value of policy:
+  switch (policy) {
+    case 'origin': return referrerOrigin != null ? referrerOrigin : stripURLForReferrer(referrerSource, true)
+    case 'unsafe-url': return referrerURL
+    case 'same-origin':
+      return areSameOrigin ? referrerOrigin : 'no-referrer'
+    case 'origin-when-cross-origin':
+      return areSameOrigin ? referrerURL : referrerOrigin
+    case 'strict-origin-when-cross-origin': {
+      const currentURL = requestCurrentURL(request)
+
+      // 1. If the origin of referrerURL and the origin of request’s current
+      //    URL are the same, then return referrerURL.
+      if (sameOrigin(referrerURL, currentURL)) {
+        return referrerURL
+      }
+
+      // 2. If referrerURL is a potentially trustworthy URL and request’s
+      //    current URL is not a potentially trustworthy URL, then return no
+      //    referrer.
+      if (isURLPotentiallyTrustworthy(referrerURL) && !isURLPotentiallyTrustworthy(currentURL)) {
+        return 'no-referrer'
+      }
+
+      // 3. Return referrerOrigin.
+      return referrerOrigin
+    }
+    case 'strict-origin': // eslint-disable-line
+      /**
+         * 1. If referrerURL is a potentially trustworthy URL and
+         * request’s current URL is not a potentially trustworthy URL,
+         * then return no referrer.
+         * 2. Return referrerOrigin
+        */
+    case 'no-referrer-when-downgrade': // eslint-disable-line
+      /**
+       * 1. If referrerURL is a potentially trustworthy URL and
+       * request’s current URL is not a potentially trustworthy URL,
+       * then return no referrer.
+       * 2. Return referrerOrigin
+      */
+
+    default: // eslint-disable-line
+      return isNonPotentiallyTrustWorthy ? 'no-referrer' : referrerOrigin
+  }
+}
+
+/**
+ * @see https://w3c.github.io/webappsec-referrer-policy/#strip-url
+ * @param {URL} url
+ * @param {boolean|undefined} originOnly
+ */
+function stripURLForReferrer (url, originOnly) {
+  // 1. Assert: url is a URL.
+  assert(url instanceof URL)
+
+  // 2. If url’s scheme is a local scheme, then return no referrer.
+  if (url.protocol === 'file:' || url.protocol === 'about:' || url.protocol === 'blank:') {
+    return 'no-referrer'
+  }
+
+  // 3. Set url’s username to the empty string.
+  url.username = ''
+
+  // 4. Set url’s password to the empty string.
+  url.password = ''
+
+  // 5. Set url’s fragment to null.
+  url.hash = ''
+
+  // 6. If the origin-only flag is true, then:
+  if (originOnly) {
+    // 1. Set url’s path to « the empty string ».
+    url.pathname = ''
+
+    // 2. Set url’s query to null.
+    url.search = ''
+  }
+
+  // 7. Return url.
+  return url
+}
+
+function isURLPotentiallyTrustworthy (url) {
+  if (!(url instanceof URL)) {
+    return false
+  }
+
+  // If child of about, return true
+  if (url.href === 'about:blank' || url.href === 'about:srcdoc') {
+    return true
+  }
+
+  // If scheme is data, return true
+  if (url.protocol === 'data:') return true
+
+  // If file, return true
+  if (url.protocol === 'file:') return true
+
+  return isOriginPotentiallyTrustworthy(url.origin)
+
+  function isOriginPotentiallyTrustworthy (origin) {
+    // If origin is explicitly null, return false
+    if (origin == null || origin === 'null') return false
+
+    const originAsURL = new URL(origin)
+
+    // If secure, return true
+    if (originAsURL.protocol === 'https:' || originAsURL.protocol === 'wss:') {
+      return true
+    }
+
+    // If localhost or variants, return true
+    if (/^127(?:\.[0-9]+){0,2}\.[0-9]+$|^\[(?:0*:)*?:?0*1\]$/.test(originAsURL.hostname) ||
+     (originAsURL.hostname === 'localhost' || originAsURL.hostname.includes('localhost.')) ||
+     (originAsURL.hostname.endsWith('.localhost'))) {
+      return true
+    }
+
+    // If any other, return false
+    return false
+  }
+}
+
+/**
+ * @see https://w3c.github.io/webappsec-subresource-integrity/#does-response-match-metadatalist
+ * @param {Uint8Array} bytes
+ * @param {string} metadataList
+ */
+function bytesMatch (bytes, metadataList) {
+  // If node is not built with OpenSSL support, we cannot check
+  // a request's integrity, so allow it by default (the spec will
+  // allow requests if an invalid hash is given, as precedence).
+  /* istanbul ignore if: only if node is built with --without-ssl */
+  if (crypto === undefined) {
+    return true
+  }
+
+  // 1. Let parsedMetadata be the result of parsing metadataList.
+  const parsedMetadata = parseMetadata(metadataList)
+
+  // 2. If parsedMetadata is no metadata, return true.
+  if (parsedMetadata === 'no metadata') {
+    return true
+  }
+
+  // 3. If parsedMetadata is the empty set, return true.
+  if (parsedMetadata.length === 0) {
+    return true
+  }
+
+  // 4. Let metadata be the result of getting the strongest
+  //    metadata from parsedMetadata.
+  const list = parsedMetadata.sort((c, d) => d.algo.localeCompare(c.algo))
+  // get the strongest algorithm
+  const strongest = list[0].algo
+  // get all entries that use the strongest algorithm; ignore weaker
+  const metadata = list.filter((item) => item.algo === strongest)
+
+  // 5. For each item in metadata:
+  for (const item of metadata) {
+    // 1. Let algorithm be the alg component of item.
+    const algorithm = item.algo
+
+    // 2. Let expectedValue be the val component of item.
+    let expectedValue = item.hash
+
+    // See https://github.com/web-platform-tests/wpt/commit/e4c5cc7a5e48093220528dfdd1c4012dc3837a0e
+    // "be liberal with padding". This is annoying, and it's not even in the spec.
+
+    if (expectedValue.endsWith('==')) {
+      expectedValue = expectedValue.slice(0, -2)
+    }
+
+    // 3. Let actualValue be the result of applying algorithm to bytes.
+    let actualValue = crypto.createHash(algorithm).update(bytes).digest('base64')
+
+    if (actualValue.endsWith('==')) {
+      actualValue = actualValue.slice(0, -2)
+    }
+
+    // 4. If actualValue is a case-sensitive match for expectedValue,
+    //    return true.
+    if (actualValue === expectedValue) {
+      return true
+    }
+
+    let actualBase64URL = crypto.createHash(algorithm).update(bytes).digest('base64url')
+
+    if (actualBase64URL.endsWith('==')) {
+      actualBase64URL = actualBase64URL.slice(0, -2)
+    }
+
+    if (actualBase64URL === expectedValue) {
+      return true
+    }
+  }
+
+  // 6. Return false.
+  return false
+}
+
+// https://w3c.github.io/webappsec-subresource-integrity/#grammardef-hash-with-options
+// https://www.w3.org/TR/CSP2/#source-list-syntax
+// https://www.rfc-editor.org/rfc/rfc5234#appendix-B.1
+const parseHashWithOptions = /((?<algo>sha256|sha384|sha512)-(?<hash>[A-z0-9+/]{1}.*={0,2}))( +[\x21-\x7e]?)?/i
+
+/**
+ * @see https://w3c.github.io/webappsec-subresource-integrity/#parse-metadata
+ * @param {string} metadata
+ */
+function parseMetadata (metadata) {
+  // 1. Let result be the empty set.
+  /** @type {{ algo: string, hash: string }[]} */
+  const result = []
+
+  // 2. Let empty be equal to true.
+  let empty = true
+
+  const supportedHashes = crypto.getHashes()
+
+  // 3. For each token returned by splitting metadata on spaces:
+  for (const token of metadata.split(' ')) {
+    // 1. Set empty to false.
+    empty = false
+
+    // 2. Parse token as a hash-with-options.
+    const parsedToken = parseHashWithOptions.exec(token)
+
+    // 3. If token does not parse, continue to the next token.
+    if (parsedToken === null || parsedToken.groups === undefined) {
+      // Note: Chromium blocks the request at this point, but Firefox
+      // gives a warning that an invalid integrity was given. The
+      // correct behavior is to ignore these, and subsequently not
+      // check the integrity of the resource.
+      continue
+    }
+
+    // 4. Let algorithm be the hash-algo component of token.
+    const algorithm = parsedToken.groups.algo
+
+    // 5. If algorithm is a hash function recognized by the user
+    //    agent, add the parsed token to result.
+    if (supportedHashes.includes(algorithm.toLowerCase())) {
+      result.push(parsedToken.groups)
+    }
+  }
+
+  // 4. Return no metadata if empty is true, otherwise return result.
+  if (empty === true) {
+    return 'no metadata'
+  }
+
+  return result
+}
+
+// https://w3c.github.io/webappsec-upgrade-insecure-requests/#upgrade-request
+function tryUpgradeRequestToAPotentiallyTrustworthyURL (request) {
+  // TODO
+}
+
+/**
+ * @link {https://html.spec.whatwg.org/multipage/origin.html#same-origin}
+ * @param {URL} A
+ * @param {URL} B
+ */
+function sameOrigin (A, B) {
+  // 1. If A and B are the same opaque origin, then return true.
+  if (A.origin === B.origin && A.origin === 'null') {
+    return true
+  }
+
+  // 2. If A and B are both tuple origins and their schemes,
+  //    hosts, and port are identical, then return true.
+  if (A.protocol === B.protocol && A.hostname === B.hostname && A.port === B.port) {
+    return true
+  }
+
+  // 3. Return false.
+  return false
+}
+
+function createDeferredPromise () {
+  let res
+  let rej
+  const promise = new Promise((resolve, reject) => {
+    res = resolve
+    rej = reject
+  })
+
+  return { promise, resolve: res, reject: rej }
+}
+
+function isAborted (fetchParams) {
+  return fetchParams.controller.state === 'aborted'
+}
+
+function isCancelled (fetchParams) {
+  return fetchParams.controller.state === 'aborted' ||
+    fetchParams.controller.state === 'terminated'
+}
+
+const normalizeMethodRecord = {
+  delete: 'DELETE',
+  DELETE: 'DELETE',
+  get: 'GET',
+  GET: 'GET',
+  head: 'HEAD',
+  HEAD: 'HEAD',
+  options: 'OPTIONS',
+  OPTIONS: 'OPTIONS',
+  post: 'POST',
+  POST: 'POST',
+  put: 'PUT',
+  PUT: 'PUT'
+}
+
+// Note: object prototypes should not be able to be referenced. e.g. `Object#hasOwnProperty`.
+Object.setPrototypeOf(normalizeMethodRecord, null)
+
+/**
+ * @see https://fetch.spec.whatwg.org/#concept-method-normalize
+ * @param {string} method
+ */
+function normalizeMethod (method) {
+  return normalizeMethodRecord[method.toLowerCase()] ?? method
+}
+
+// https://infra.spec.whatwg.org/#serialize-a-javascript-value-to-a-json-string
+function serializeJavascriptValueToJSONString (value) {
+  // 1. Let result be ? Call(%JSON.stringify%, undefined, « value »).
+  const result = JSON.stringify(value)
+
+  // 2. If result is undefined, then throw a TypeError.
+  if (result === undefined) {
+    throw new TypeError('Value is not JSON serializable')
+  }
+
+  // 3. Assert: result is a string.
+  assert(typeof result === 'string')
+
+  // 4. Return result.
+  return result
+}
+
+// https://tc39.es/ecma262/#sec-%25iteratorprototype%25-object
+const esIteratorPrototype = Object.getPrototypeOf(Object.getPrototypeOf([][Symbol.iterator]()))
+
+/**
+ * @see https://webidl.spec.whatwg.org/#dfn-iterator-prototype-object
+ * @param {() => unknown[]} iterator
+ * @param {string} name name of the instance
+ * @param {'key'|'value'|'key+value'} kind
+ */
+function makeIterator (iterator, name, kind) {
+  const object = {
+    index: 0,
+    kind,
+    target: iterator
+  }
+
+  const i = {
+    next () {
+      // 1. Let interface be the interface for which the iterator prototype object exists.
+
+      // 2. Let thisValue be the this value.
+
+      // 3. Let object be ? ToObject(thisValue).
+
+      // 4. If object is a platform object, then perform a security
+      //    check, passing:
+
+      // 5. If object is not a default iterator object for interface,
+      //    then throw a TypeError.
+      if (Object.getPrototypeOf(this) !== i) {
+        throw new TypeError(
+          `'next' called on an object that does not implement interface ${name} Iterator.`
+        )
+      }
+
+      // 6. Let index be object’s index.
+      // 7. Let kind be object’s kind.
+      // 8. Let values be object’s target's value pairs to iterate over.
+      const { index, kind, target } = object
+      const values = target()
+
+      // 9. Let len be the length of values.
+      const len = values.length
+
+      // 10. If index is greater than or equal to len, then return
+      //     CreateIterResultObject(undefined, true).
+      if (index >= len) {
+        return { value: undefined, done: true }
+      }
+
+      // 11. Let pair be the entry in values at index index.
+      const pair = values[index]
+
+      // 12. Set object’s index to index + 1.
+      object.index = index + 1
+
+      // 13. Return the iterator result for pair and kind.
+      return iteratorResult(pair, kind)
+    },
+    // The class string of an iterator prototype object for a given interface is the
+    // result of concatenating the identifier of the interface and the string " Iterator".
+    [Symbol.toStringTag]: `${name} Iterator`
+  }
+
+  // The [[Prototype]] internal slot of an iterator prototype object must be %IteratorPrototype%.
+  Object.setPrototypeOf(i, esIteratorPrototype)
+  // esIteratorPrototype needs to be the prototype of i
+  // which is the prototype of an empty object. Yes, it's confusing.
+  return Object.setPrototypeOf({}, i)
+}
+
+// https://webidl.spec.whatwg.org/#iterator-result
+function iteratorResult (pair, kind) {
+  let result
+
+  // 1. Let result be a value determined by the value of kind:
+  switch (kind) {
+    case 'key': {
+      // 1. Let idlKey be pair’s key.
+      // 2. Let key be the result of converting idlKey to an
+      //    ECMAScript value.
+      // 3. result is key.
+      result = pair[0]
+      break
+    }
+    case 'value': {
+      // 1. Let idlValue be pair’s value.
+      // 2. Let value be the result of converting idlValue to
+      //    an ECMAScript value.
+      // 3. result is value.
+      result = pair[1]
+      break
+    }
+    case 'key+value': {
+      // 1. Let idlKey be pair’s key.
+      // 2. Let idlValue be pair’s value.
+      // 3. Let key be the result of converting idlKey to an
+      //    ECMAScript value.
+      // 4. Let value be the result of converting idlValue to
+      //    an ECMAScript value.
+      // 5. Let array be ! ArrayCreate(2).
+      // 6. Call ! CreateDataProperty(array, "0", key).
+      // 7. Call ! CreateDataProperty(array, "1", value).
+      // 8. result is array.
+      result = pair
+      break
+    }
+  }
+
+  // 2. Return CreateIterResultObject(result, false).
+  return { value: result, done: false }
+}
+
+/**
+ * @see https://fetch.spec.whatwg.org/#body-fully-read
+ */
+async function fullyReadBody (body, processBody, processBodyError) {
+  // 1. If taskDestination is null, then set taskDestination to
+  //    the result of starting a new parallel queue.
+
+  // 2. Let successSteps given a byte sequence bytes be to queue a
+  //    fetch task to run processBody given bytes, with taskDestination.
+  const successSteps = processBody
+
+  // 3. Let errorSteps be to queue a fetch task to run processBodyError,
+  //    with taskDestination.
+  const errorSteps = processBodyError
+
+  // 4. Let reader be the result of getting a reader for body’s stream.
+  //    If that threw an exception, then run errorSteps with that
+  //    exception and return.
+  let reader
+
+  try {
+    reader = body.stream.getReader()
+  } catch (e) {
+    errorSteps(e)
+    return
+  }
+
+  // 5. Read all bytes from reader, given successSteps and errorSteps.
+  try {
+    const result = await readAllBytes(reader)
+    successSteps(result)
+  } catch (e) {
+    errorSteps(e)
+  }
+}
+
+/** @type {ReadableStream} */
+let ReadableStream = globalThis.ReadableStream
+
+function isReadableStreamLike (stream) {
+  if (!ReadableStream) {
+    ReadableStream = require('stream/web').ReadableStream
+  }
+
+  return stream instanceof ReadableStream || (
+    stream[Symbol.toStringTag] === 'ReadableStream' &&
+    typeof stream.tee === 'function'
+  )
+}
+
+const MAXIMUM_ARGUMENT_LENGTH = 65535
+
+/**
+ * @see https://infra.spec.whatwg.org/#isomorphic-decode
+ * @param {number[]|Uint8Array} input
+ */
+function isomorphicDecode (input) {
+  // 1. To isomorphic decode a byte sequence input, return a string whose code point
+  //    length is equal to input’s length and whose code points have the same values
+  //    as the values of input’s bytes, in the same order.
+
+  if (input.length < MAXIMUM_ARGUMENT_LENGTH) {
+    return String.fromCharCode(...input)
+  }
+
+  return input.reduce((previous, current) => previous + String.fromCharCode(current), '')
+}
+
+/**
+ * @param {ReadableStreamController<Uint8Array>} controller
+ */
+function readableStreamClose (controller) {
+  try {
+    controller.close()
+  } catch (err) {
+    // TODO: add comment explaining why this error occurs.
+    if (!err.message.includes('Controller is already closed')) {
+      throw err
+    }
+  }
+}
+
+/**
+ * @see https://infra.spec.whatwg.org/#isomorphic-encode
+ * @param {string} input
+ */
+function isomorphicEncode (input) {
+  // 1. Assert: input contains no code points greater than U+00FF.
+  for (let i = 0; i < input.length; i++) {
+    assert(input.charCodeAt(i) <= 0xFF)
+  }
+
+  // 2. Return a byte sequence whose length is equal to input’s code
+  //    point length and whose bytes have the same values as the
+  //    values of input’s code points, in the same order
+  return input
+}
+
+/**
+ * @see https://streams.spec.whatwg.org/#readablestreamdefaultreader-read-all-bytes
+ * @see https://streams.spec.whatwg.org/#read-loop
+ * @param {ReadableStreamDefaultReader} reader
+ */
+async function readAllBytes (reader) {
+  const bytes = []
+  let byteLength = 0
+
+  while (true) {
+    const { done, value: chunk } = await reader.read()
+
+    if (done) {
+      // 1. Call successSteps with bytes.
+      return Buffer.concat(bytes, byteLength)
+    }
+
+    // 1. If chunk is not a Uint8Array object, call failureSteps
+    //    with a TypeError and abort these steps.
+    if (!isUint8Array(chunk)) {
+      throw new TypeError('Received non-Uint8Array chunk')
+    }
+
+    // 2. Append the bytes represented by chunk to bytes.
+    bytes.push(chunk)
+    byteLength += chunk.length
+
+    // 3. Read-loop given reader, bytes, successSteps, and failureSteps.
+  }
+}
+
+/**
+ * @see https://fetch.spec.whatwg.org/#is-local
+ * @param {URL} url
+ */
+function urlIsLocal (url) {
+  assert('protocol' in url) // ensure it's a url object
+
+  const protocol = url.protocol
+
+  return protocol === 'about:' || protocol === 'blob:' || protocol === 'data:'
+}
+
+/**
+ * @param {string|URL} url
+ */
+function urlHasHttpsScheme (url) {
+  if (typeof url === 'string') {
+    return url.startsWith('https:')
+  }
+
+  return url.protocol === 'https:'
+}
+
+/**
+ * @see https://fetch.spec.whatwg.org/#http-scheme
+ * @param {URL} url
+ */
+function urlIsHttpHttpsScheme (url) {
+  assert('protocol' in url) // ensure it's a url object
+
+  const protocol = url.protocol
+
+  return protocol === 'http:' || protocol === 'https:'
+}
+
+/**
+ * Fetch supports node >= 16.8.0, but Object.hasOwn was added in v16.9.0.
+ */
+const hasOwn = Object.hasOwn || ((dict, key) => Object.prototype.hasOwnProperty.call(dict, key))
+
+module.exports = {
+  isAborted,
+  isCancelled,
+  createDeferredPromise,
+  ReadableStreamFrom,
+  toUSVString,
+  tryUpgradeRequestToAPotentiallyTrustworthyURL,
+  coarsenedSharedCurrentTime,
+  determineRequestsReferrer,
+  makePolicyContainer,
+  clonePolicyContainer,
+  appendFetchMetadata,
+  appendRequestOriginHeader,
+  TAOCheck,
+  corsCheck,
+  crossOriginResourcePolicyCheck,
+  createOpaqueTimingInfo,
+  setRequestReferrerPolicyOnRedirect,
+  isValidHTTPToken,
+  requestBadPort,
+  requestCurrentURL,
+  responseURL,
+  responseLocationURL,
+  isBlobLike,
+  isURLPotentiallyTrustworthy,
+  isValidReasonPhrase,
+  sameOrigin,
+  normalizeMethod,
+  serializeJavascriptValueToJSONString,
+  makeIterator,
+  isValidHeaderName,
+  isValidHeaderValue,
+  hasOwn,
+  isErrorLike,
+  fullyReadBody,
+  bytesMatch,
+  isReadableStreamLike,
+  readableStreamClose,
+  isomorphicEncode,
+  isomorphicDecode,
+  urlIsLocal,
+  urlHasHttpsScheme,
+  urlIsHttpHttpsScheme,
+  readAllBytes,
+  normalizeMethodRecord
+}