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>

4 files changed, 804 insertions, 0 deletions

diff --git a/lib/cookies/constants.js b/lib/cookies/constants.js
new file mode 100644
index 0000000..85f1fec
--- /dev/null
+++ b/lib/cookies/constants.js
@@ -0,0 +1,12 @@
+'use strict'
+
+// https://wicg.github.io/cookie-store/#cookie-maximum-attribute-value-size
+const maxAttributeValueSize = 1024
+
+// https://wicg.github.io/cookie-store/#cookie-maximum-name-value-pair-size
+const maxNameValuePairSize = 4096
+
+module.exports = {
+  maxAttributeValueSize,
+  maxNameValuePairSize
+}
diff --git a/lib/cookies/index.js b/lib/cookies/index.js
new file mode 100644
index 0000000..c9c1f28
--- /dev/null
+++ b/lib/cookies/index.js
@@ -0,0 +1,184 @@
+'use strict'
+
+const { parseSetCookie } = require('./parse')
+const { stringify, getHeadersList } = require('./util')
+const { webidl } = require('../fetch/webidl')
+const { Headers } = require('../fetch/headers')
+
+/**
+ * @typedef {Object} Cookie
+ * @property {string} name
+ * @property {string} value
+ * @property {Date|number|undefined} expires
+ * @property {number|undefined} maxAge
+ * @property {string|undefined} domain
+ * @property {string|undefined} path
+ * @property {boolean|undefined} secure
+ * @property {boolean|undefined} httpOnly
+ * @property {'Strict'|'Lax'|'None'} sameSite
+ * @property {string[]} unparsed
+ */
+
+/**
+ * @param {Headers} headers
+ * @returns {Record<string, string>}
+ */
+function getCookies (headers) {
+  webidl.argumentLengthCheck(arguments, 1, { header: 'getCookies' })
+
+  webidl.brandCheck(headers, Headers, { strict: false })
+
+  const cookie = headers.get('cookie')
+  const out = {}
+
+  if (!cookie) {
+    return out
+  }
+
+  for (const piece of cookie.split(';')) {
+    const [name, ...value] = piece.split('=')
+
+    out[name.trim()] = value.join('=')
+  }
+
+  return out
+}
+
+/**
+ * @param {Headers} headers
+ * @param {string} name
+ * @param {{ path?: string, domain?: string }|undefined} attributes
+ * @returns {void}
+ */
+function deleteCookie (headers, name, attributes) {
+  webidl.argumentLengthCheck(arguments, 2, { header: 'deleteCookie' })
+
+  webidl.brandCheck(headers, Headers, { strict: false })
+
+  name = webidl.converters.DOMString(name)
+  attributes = webidl.converters.DeleteCookieAttributes(attributes)
+
+  // Matches behavior of
+  // https://github.com/denoland/deno_std/blob/63827b16330b82489a04614027c33b7904e08be5/http/cookie.ts#L278
+  setCookie(headers, {
+    name,
+    value: '',
+    expires: new Date(0),
+    ...attributes
+  })
+}
+
+/**
+ * @param {Headers} headers
+ * @returns {Cookie[]}
+ */
+function getSetCookies (headers) {
+  webidl.argumentLengthCheck(arguments, 1, { header: 'getSetCookies' })
+
+  webidl.brandCheck(headers, Headers, { strict: false })
+
+  const cookies = getHeadersList(headers).cookies
+
+  if (!cookies) {
+    return []
+  }
+
+  // In older versions of undici, cookies is a list of name:value.
+  return cookies.map((pair) => parseSetCookie(Array.isArray(pair) ? pair[1] : pair))
+}
+
+/**
+ * @param {Headers} headers
+ * @param {Cookie} cookie
+ * @returns {void}
+ */
+function setCookie (headers, cookie) {
+  webidl.argumentLengthCheck(arguments, 2, { header: 'setCookie' })
+
+  webidl.brandCheck(headers, Headers, { strict: false })
+
+  cookie = webidl.converters.Cookie(cookie)
+
+  const str = stringify(cookie)
+
+  if (str) {
+    headers.append('Set-Cookie', stringify(cookie))
+  }
+}
+
+webidl.converters.DeleteCookieAttributes = webidl.dictionaryConverter([
+  {
+    converter: webidl.nullableConverter(webidl.converters.DOMString),
+    key: 'path',
+    defaultValue: null
+  },
+  {
+    converter: webidl.nullableConverter(webidl.converters.DOMString),
+    key: 'domain',
+    defaultValue: null
+  }
+])
+
+webidl.converters.Cookie = webidl.dictionaryConverter([
+  {
+    converter: webidl.converters.DOMString,
+    key: 'name'
+  },
+  {
+    converter: webidl.converters.DOMString,
+    key: 'value'
+  },
+  {
+    converter: webidl.nullableConverter((value) => {
+      if (typeof value === 'number') {
+        return webidl.converters['unsigned long long'](value)
+      }
+
+      return new Date(value)
+    }),
+    key: 'expires',
+    defaultValue: null
+  },
+  {
+    converter: webidl.nullableConverter(webidl.converters['long long']),
+    key: 'maxAge',
+    defaultValue: null
+  },
+  {
+    converter: webidl.nullableConverter(webidl.converters.DOMString),
+    key: 'domain',
+    defaultValue: null
+  },
+  {
+    converter: webidl.nullableConverter(webidl.converters.DOMString),
+    key: 'path',
+    defaultValue: null
+  },
+  {
+    converter: webidl.nullableConverter(webidl.converters.boolean),
+    key: 'secure',
+    defaultValue: null
+  },
+  {
+    converter: webidl.nullableConverter(webidl.converters.boolean),
+    key: 'httpOnly',
+    defaultValue: null
+  },
+  {
+    converter: webidl.converters.USVString,
+    key: 'sameSite',
+    allowedValues: ['Strict', 'Lax', 'None']
+  },
+  {
+    converter: webidl.sequenceConverter(webidl.converters.DOMString),
+    key: 'unparsed',
+    defaultValue: []
+  }
+])
+
+module.exports = {
+  getCookies,
+  deleteCookie,
+  getSetCookies,
+  setCookie
+}
diff --git a/lib/cookies/parse.js b/lib/cookies/parse.js
new file mode 100644
index 0000000..aae2750
--- /dev/null
+++ b/lib/cookies/parse.js
@@ -0,0 +1,317 @@
+'use strict'
+
+const { maxNameValuePairSize, maxAttributeValueSize } = require('./constants')
+const { isCTLExcludingHtab } = require('./util')
+const { collectASequenceOfCodePointsFast } = require('../fetch/dataURL')
+const assert = require('assert')
+
+/**
+ * @description Parses the field-value attributes of a set-cookie header string.
+ * @see https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4
+ * @param {string} header
+ * @returns if the header is invalid, null will be returned
+ */
+function parseSetCookie (header) {
+  // 1. If the set-cookie-string contains a %x00-08 / %x0A-1F / %x7F
+  //    character (CTL characters excluding HTAB): Abort these steps and
+  //    ignore the set-cookie-string entirely.
+  if (isCTLExcludingHtab(header)) {
+    return null
+  }
+
+  let nameValuePair = ''
+  let unparsedAttributes = ''
+  let name = ''
+  let value = ''
+
+  // 2. If the set-cookie-string contains a %x3B (";") character:
+  if (header.includes(';')) {
+    // 1. The name-value-pair string consists of the characters up to,
+    //    but not including, the first %x3B (";"), and the unparsed-
+    //    attributes consist of the remainder of the set-cookie-string
+    //    (including the %x3B (";") in question).
+    const position = { position: 0 }
+
+    nameValuePair = collectASequenceOfCodePointsFast(';', header, position)
+    unparsedAttributes = header.slice(position.position)
+  } else {
+    // Otherwise:
+
+    // 1. The name-value-pair string consists of all the characters
+    //    contained in the set-cookie-string, and the unparsed-
+    //    attributes is the empty string.
+    nameValuePair = header
+  }
+
+  // 3. If the name-value-pair string lacks a %x3D ("=") character, then
+  //    the name string is empty, and the value string is the value of
+  //    name-value-pair.
+  if (!nameValuePair.includes('=')) {
+    value = nameValuePair
+  } else {
+    //    Otherwise, the name string consists of the characters up to, but
+    //    not including, the first %x3D ("=") character, and the (possibly
+    //    empty) value string consists of the characters after the first
+    //    %x3D ("=") character.
+    const position = { position: 0 }
+    name = collectASequenceOfCodePointsFast(
+      '=',
+      nameValuePair,
+      position
+    )
+    value = nameValuePair.slice(position.position + 1)
+  }
+
+  // 4. Remove any leading or trailing WSP characters from the name
+  //    string and the value string.
+  name = name.trim()
+  value = value.trim()
+
+  // 5. If the sum of the lengths of the name string and the value string
+  //    is more than 4096 octets, abort these steps and ignore the set-
+  //    cookie-string entirely.
+  if (name.length + value.length > maxNameValuePairSize) {
+    return null
+  }
+
+  // 6. The cookie-name is the name string, and the cookie-value is the
+  //    value string.
+  return {
+    name, value, ...parseUnparsedAttributes(unparsedAttributes)
+  }
+}
+
+/**
+ * Parses the remaining attributes of a set-cookie header
+ * @see https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4
+ * @param {string} unparsedAttributes
+ * @param {[Object.<string, unknown>]={}} cookieAttributeList
+ */
+function parseUnparsedAttributes (unparsedAttributes, cookieAttributeList = {}) {
+  // 1. If the unparsed-attributes string is empty, skip the rest of
+  //    these steps.
+  if (unparsedAttributes.length === 0) {
+    return cookieAttributeList
+  }
+
+  // 2. Discard the first character of the unparsed-attributes (which
+  //    will be a %x3B (";") character).
+  assert(unparsedAttributes[0] === ';')
+  unparsedAttributes = unparsedAttributes.slice(1)
+
+  let cookieAv = ''
+
+  // 3. If the remaining unparsed-attributes contains a %x3B (";")
+  //    character:
+  if (unparsedAttributes.includes(';')) {
+    // 1. Consume the characters of the unparsed-attributes up to, but
+    //    not including, the first %x3B (";") character.
+    cookieAv = collectASequenceOfCodePointsFast(
+      ';',
+      unparsedAttributes,
+      { position: 0 }
+    )
+    unparsedAttributes = unparsedAttributes.slice(cookieAv.length)
+  } else {
+    // Otherwise:
+
+    // 1. Consume the remainder of the unparsed-attributes.
+    cookieAv = unparsedAttributes
+    unparsedAttributes = ''
+  }
+
+  // Let the cookie-av string be the characters consumed in this step.
+
+  let attributeName = ''
+  let attributeValue = ''
+
+  // 4. If the cookie-av string contains a %x3D ("=") character:
+  if (cookieAv.includes('=')) {
+    // 1. The (possibly empty) attribute-name string consists of the
+    //    characters up to, but not including, the first %x3D ("=")
+    //    character, and the (possibly empty) attribute-value string
+    //    consists of the characters after the first %x3D ("=")
+    //    character.
+    const position = { position: 0 }
+
+    attributeName = collectASequenceOfCodePointsFast(
+      '=',
+      cookieAv,
+      position
+    )
+    attributeValue = cookieAv.slice(position.position + 1)
+  } else {
+    // Otherwise:
+
+    // 1. The attribute-name string consists of the entire cookie-av
+    //    string, and the attribute-value string is empty.
+    attributeName = cookieAv
+  }
+
+  // 5. Remove any leading or trailing WSP characters from the attribute-
+  //    name string and the attribute-value string.
+  attributeName = attributeName.trim()
+  attributeValue = attributeValue.trim()
+
+  // 6. If the attribute-value is longer than 1024 octets, ignore the
+  //    cookie-av string and return to Step 1 of this algorithm.
+  if (attributeValue.length > maxAttributeValueSize) {
+    return parseUnparsedAttributes(unparsedAttributes, cookieAttributeList)
+  }
+
+  // 7. Process the attribute-name and attribute-value according to the
+  //    requirements in the following subsections.  (Notice that
+  //    attributes with unrecognized attribute-names are ignored.)
+  const attributeNameLowercase = attributeName.toLowerCase()
+
+  // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.1
+  // If the attribute-name case-insensitively matches the string
+  // "Expires", the user agent MUST process the cookie-av as follows.
+  if (attributeNameLowercase === 'expires') {
+    // 1. Let the expiry-time be the result of parsing the attribute-value
+    //    as cookie-date (see Section 5.1.1).
+    const expiryTime = new Date(attributeValue)
+
+    // 2. If the attribute-value failed to parse as a cookie date, ignore
+    //    the cookie-av.
+
+    cookieAttributeList.expires = expiryTime
+  } else if (attributeNameLowercase === 'max-age') {
+    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.2
+    // If the attribute-name case-insensitively matches the string "Max-
+    // Age", the user agent MUST process the cookie-av as follows.
+
+    // 1. If the first character of the attribute-value is not a DIGIT or a
+    //    "-" character, ignore the cookie-av.
+    const charCode = attributeValue.charCodeAt(0)
+
+    if ((charCode < 48 || charCode > 57) && attributeValue[0] !== '-') {
+      return parseUnparsedAttributes(unparsedAttributes, cookieAttributeList)
+    }
+
+    // 2. If the remainder of attribute-value contains a non-DIGIT
+    //    character, ignore the cookie-av.
+    if (!/^\d+$/.test(attributeValue)) {
+      return parseUnparsedAttributes(unparsedAttributes, cookieAttributeList)
+    }
+
+    // 3. Let delta-seconds be the attribute-value converted to an integer.
+    const deltaSeconds = Number(attributeValue)
+
+    // 4. Let cookie-age-limit be the maximum age of the cookie (which
+    //    SHOULD be 400 days or less, see Section 4.1.2.2).
+
+    // 5. Set delta-seconds to the smaller of its present value and cookie-
+    //    age-limit.
+    // deltaSeconds = Math.min(deltaSeconds * 1000, maxExpiresMs)
+
+    // 6. If delta-seconds is less than or equal to zero (0), let expiry-
+    //    time be the earliest representable date and time.  Otherwise, let
+    //    the expiry-time be the current date and time plus delta-seconds
+    //    seconds.
+    // const expiryTime = deltaSeconds <= 0 ? Date.now() : Date.now() + deltaSeconds
+
+    // 7. Append an attribute to the cookie-attribute-list with an
+    //    attribute-name of Max-Age and an attribute-value of expiry-time.
+    cookieAttributeList.maxAge = deltaSeconds
+  } else if (attributeNameLowercase === 'domain') {
+    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.3
+    // If the attribute-name case-insensitively matches the string "Domain",
+    // the user agent MUST process the cookie-av as follows.
+
+    // 1. Let cookie-domain be the attribute-value.
+    let cookieDomain = attributeValue
+
+    // 2. If cookie-domain starts with %x2E ("."), let cookie-domain be
+    //    cookie-domain without its leading %x2E (".").
+    if (cookieDomain[0] === '.') {
+      cookieDomain = cookieDomain.slice(1)
+    }
+
+    // 3. Convert the cookie-domain to lower case.
+    cookieDomain = cookieDomain.toLowerCase()
+
+    // 4. Append an attribute to the cookie-attribute-list with an
+    //    attribute-name of Domain and an attribute-value of cookie-domain.
+    cookieAttributeList.domain = cookieDomain
+  } else if (attributeNameLowercase === 'path') {
+    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.4
+    // If the attribute-name case-insensitively matches the string "Path",
+    // the user agent MUST process the cookie-av as follows.
+
+    // 1. If the attribute-value is empty or if the first character of the
+    //    attribute-value is not %x2F ("/"):
+    let cookiePath = ''
+    if (attributeValue.length === 0 || attributeValue[0] !== '/') {
+      // 1. Let cookie-path be the default-path.
+      cookiePath = '/'
+    } else {
+      // Otherwise:
+
+      // 1. Let cookie-path be the attribute-value.
+      cookiePath = attributeValue
+    }
+
+    // 2. Append an attribute to the cookie-attribute-list with an
+    //    attribute-name of Path and an attribute-value of cookie-path.
+    cookieAttributeList.path = cookiePath
+  } else if (attributeNameLowercase === 'secure') {
+    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.5
+    // If the attribute-name case-insensitively matches the string "Secure",
+    // the user agent MUST append an attribute to the cookie-attribute-list
+    // with an attribute-name of Secure and an empty attribute-value.
+
+    cookieAttributeList.secure = true
+  } else if (attributeNameLowercase === 'httponly') {
+    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.6
+    // If the attribute-name case-insensitively matches the string
+    // "HttpOnly", the user agent MUST append an attribute to the cookie-
+    // attribute-list with an attribute-name of HttpOnly and an empty
+    // attribute-value.
+
+    cookieAttributeList.httpOnly = true
+  } else if (attributeNameLowercase === 'samesite') {
+    // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-rfc6265bis#section-5.4.7
+    // If the attribute-name case-insensitively matches the string
+    // "SameSite", the user agent MUST process the cookie-av as follows:
+
+    // 1. Let enforcement be "Default".
+    let enforcement = 'Default'
+
+    const attributeValueLowercase = attributeValue.toLowerCase()
+    // 2. If cookie-av's attribute-value is a case-insensitive match for
+    //    "None", set enforcement to "None".
+    if (attributeValueLowercase.includes('none')) {
+      enforcement = 'None'
+    }
+
+    // 3. If cookie-av's attribute-value is a case-insensitive match for
+    //    "Strict", set enforcement to "Strict".
+    if (attributeValueLowercase.includes('strict')) {
+      enforcement = 'Strict'
+    }
+
+    // 4. If cookie-av's attribute-value is a case-insensitive match for
+    //    "Lax", set enforcement to "Lax".
+    if (attributeValueLowercase.includes('lax')) {
+      enforcement = 'Lax'
+    }
+
+    // 5. Append an attribute to the cookie-attribute-list with an
+    //    attribute-name of "SameSite" and an attribute-value of
+    //    enforcement.
+    cookieAttributeList.sameSite = enforcement
+  } else {
+    cookieAttributeList.unparsed ??= []
+
+    cookieAttributeList.unparsed.push(`${attributeName}=${attributeValue}`)
+  }
+
+  // 8. Return to Step 1 of this algorithm.
+  return parseUnparsedAttributes(unparsedAttributes, cookieAttributeList)
+}
+
+module.exports = {
+  parseSetCookie,
+  parseUnparsedAttributes
+}
diff --git a/lib/cookies/util.js b/lib/cookies/util.js
new file mode 100644
index 0000000..2290329
--- /dev/null
+++ b/lib/cookies/util.js
@@ -0,0 +1,291 @@
+'use strict'
+
+const assert = require('assert')
+const { kHeadersList } = require('../core/symbols')
+
+function isCTLExcludingHtab (value) {
+  if (value.length === 0) {
+    return false
+  }
+
+  for (const char of value) {
+    const code = char.charCodeAt(0)
+
+    if (
+      (code >= 0x00 || code <= 0x08) ||
+      (code >= 0x0A || code <= 0x1F) ||
+      code === 0x7F
+    ) {
+      return false
+    }
+  }
+}
+
+/**
+ CHAR           = <any US-ASCII character (octets 0 - 127)>
+ token          = 1*<any CHAR except CTLs or separators>
+ separators     = "(" | ")" | "<" | ">" | "@"
+                | "," | ";" | ":" | "\" | <">
+                | "/" | "[" | "]" | "?" | "="
+                | "{" | "}" | SP | HT
+ * @param {string} name
+ */
+function validateCookieName (name) {
+  for (const char of name) {
+    const code = char.charCodeAt(0)
+
+    if (
+      (code <= 0x20 || code > 0x7F) ||
+      char === '(' ||
+      char === ')' ||
+      char === '>' ||
+      char === '<' ||
+      char === '@' ||
+      char === ',' ||
+      char === ';' ||
+      char === ':' ||
+      char === '\\' ||
+      char === '"' ||
+      char === '/' ||
+      char === '[' ||
+      char === ']' ||
+      char === '?' ||
+      char === '=' ||
+      char === '{' ||
+      char === '}'
+    ) {
+      throw new Error('Invalid cookie name')
+    }
+  }
+}
+
+/**
+ cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
+ cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
+                       ; US-ASCII characters excluding CTLs,
+                       ; whitespace DQUOTE, comma, semicolon,
+                       ; and backslash
+ * @param {string} value
+ */
+function validateCookieValue (value) {
+  for (const char of value) {
+    const code = char.charCodeAt(0)
+
+    if (
+      code < 0x21 || // exclude CTLs (0-31)
+      code === 0x22 ||
+      code === 0x2C ||
+      code === 0x3B ||
+      code === 0x5C ||
+      code > 0x7E // non-ascii
+    ) {
+      throw new Error('Invalid header value')
+    }
+  }
+}
+
+/**
+ * path-value        = <any CHAR except CTLs or ";">
+ * @param {string} path
+ */
+function validateCookiePath (path) {
+  for (const char of path) {
+    const code = char.charCodeAt(0)
+
+    if (code < 0x21 || char === ';') {
+      throw new Error('Invalid cookie path')
+    }
+  }
+}
+
+/**
+ * I have no idea why these values aren't allowed to be honest,
+ * but Deno tests these. - Khafra
+ * @param {string} domain
+ */
+function validateCookieDomain (domain) {
+  if (
+    domain.startsWith('-') ||
+    domain.endsWith('.') ||
+    domain.endsWith('-')
+  ) {
+    throw new Error('Invalid cookie domain')
+  }
+}
+
+/**
+ * @see https://www.rfc-editor.org/rfc/rfc7231#section-7.1.1.1
+ * @param {number|Date} date
+  IMF-fixdate  = day-name "," SP date1 SP time-of-day SP GMT
+  ; fixed length/zone/capitalization subset of the format
+  ; see Section 3.3 of [RFC5322]
+
+  day-name     = %x4D.6F.6E ; "Mon", case-sensitive
+              / %x54.75.65 ; "Tue", case-sensitive
+              / %x57.65.64 ; "Wed", case-sensitive
+              / %x54.68.75 ; "Thu", case-sensitive
+              / %x46.72.69 ; "Fri", case-sensitive
+              / %x53.61.74 ; "Sat", case-sensitive
+              / %x53.75.6E ; "Sun", case-sensitive
+  date1        = day SP month SP year
+                  ; e.g., 02 Jun 1982
+
+  day          = 2DIGIT
+  month        = %x4A.61.6E ; "Jan", case-sensitive
+              / %x46.65.62 ; "Feb", case-sensitive
+              / %x4D.61.72 ; "Mar", case-sensitive
+              / %x41.70.72 ; "Apr", case-sensitive
+              / %x4D.61.79 ; "May", case-sensitive
+              / %x4A.75.6E ; "Jun", case-sensitive
+              / %x4A.75.6C ; "Jul", case-sensitive
+              / %x41.75.67 ; "Aug", case-sensitive
+              / %x53.65.70 ; "Sep", case-sensitive
+              / %x4F.63.74 ; "Oct", case-sensitive
+              / %x4E.6F.76 ; "Nov", case-sensitive
+              / %x44.65.63 ; "Dec", case-sensitive
+  year         = 4DIGIT
+
+  GMT          = %x47.4D.54 ; "GMT", case-sensitive
+
+  time-of-day  = hour ":" minute ":" second
+              ; 00:00:00 - 23:59:60 (leap second)
+
+  hour         = 2DIGIT
+  minute       = 2DIGIT
+  second       = 2DIGIT
+ */
+function toIMFDate (date) {
+  if (typeof date === 'number') {
+    date = new Date(date)
+  }
+
+  const days = [
+    'Sun', 'Mon', 'Tue', 'Wed',
+    'Thu', 'Fri', 'Sat'
+  ]
+
+  const months = [
+    'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+    'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'
+  ]
+
+  const dayName = days[date.getUTCDay()]
+  const day = date.getUTCDate().toString().padStart(2, '0')
+  const month = months[date.getUTCMonth()]
+  const year = date.getUTCFullYear()
+  const hour = date.getUTCHours().toString().padStart(2, '0')
+  const minute = date.getUTCMinutes().toString().padStart(2, '0')
+  const second = date.getUTCSeconds().toString().padStart(2, '0')
+
+  return `${dayName}, ${day} ${month} ${year} ${hour}:${minute}:${second} GMT`
+}
+
+/**
+ max-age-av        = "Max-Age=" non-zero-digit *DIGIT
+                       ; In practice, both expires-av and max-age-av
+                       ; are limited to dates representable by the
+                       ; user agent.
+ * @param {number} maxAge
+ */
+function validateCookieMaxAge (maxAge) {
+  if (maxAge < 0) {
+    throw new Error('Invalid cookie max-age')
+  }
+}
+
+/**
+ * @see https://www.rfc-editor.org/rfc/rfc6265#section-4.1.1
+ * @param {import('./index').Cookie} cookie
+ */
+function stringify (cookie) {
+  if (cookie.name.length === 0) {
+    return null
+  }
+
+  validateCookieName(cookie.name)
+  validateCookieValue(cookie.value)
+
+  const out = [`${cookie.name}=${cookie.value}`]
+
+  // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-cookie-prefixes-00#section-3.1
+  // https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-cookie-prefixes-00#section-3.2
+  if (cookie.name.startsWith('__Secure-')) {
+    cookie.secure = true
+  }
+
+  if (cookie.name.startsWith('__Host-')) {
+    cookie.secure = true
+    cookie.domain = null
+    cookie.path = '/'
+  }
+
+  if (cookie.secure) {
+    out.push('Secure')
+  }
+
+  if (cookie.httpOnly) {
+    out.push('HttpOnly')
+  }
+
+  if (typeof cookie.maxAge === 'number') {
+    validateCookieMaxAge(cookie.maxAge)
+    out.push(`Max-Age=${cookie.maxAge}`)
+  }
+
+  if (cookie.domain) {
+    validateCookieDomain(cookie.domain)
+    out.push(`Domain=${cookie.domain}`)
+  }
+
+  if (cookie.path) {
+    validateCookiePath(cookie.path)
+    out.push(`Path=${cookie.path}`)
+  }
+
+  if (cookie.expires && cookie.expires.toString() !== 'Invalid Date') {
+    out.push(`Expires=${toIMFDate(cookie.expires)}`)
+  }
+
+  if (cookie.sameSite) {
+    out.push(`SameSite=${cookie.sameSite}`)
+  }
+
+  for (const part of cookie.unparsed) {
+    if (!part.includes('=')) {
+      throw new Error('Invalid unparsed')
+    }
+
+    const [key, ...value] = part.split('=')
+
+    out.push(`${key.trim()}=${value.join('=')}`)
+  }
+
+  return out.join('; ')
+}
+
+let kHeadersListNode
+
+function getHeadersList (headers) {
+  if (headers[kHeadersList]) {
+    return headers[kHeadersList]
+  }
+
+  if (!kHeadersListNode) {
+    kHeadersListNode = Object.getOwnPropertySymbols(headers).find(
+      (symbol) => symbol.description === 'headers list'
+    )
+
+    assert(kHeadersListNode, 'Headers cannot be parsed')
+  }
+
+  const headersList = headers[kHeadersListNode]
+  assert(headersList)
+
+  return headersList
+}
+
+module.exports = {
+  isCTLExcludingHtab,
+  stringify,
+  getHeadersList
+}