576 lines
17 KiB
JavaScript
576 lines
17 KiB
JavaScript
'use strict'
|
||
|
||
const { bufferToLowerCasedHeaderName } = require('../../core/util')
|
||
const { HTTP_TOKEN_CODEPOINTS } = require('./data-url')
|
||
const { makeEntry } = require('./formdata')
|
||
const { webidl } = require('../webidl')
|
||
const assert = require('node:assert')
|
||
const { isomorphicDecode } = require('../infra')
|
||
const { utf8DecodeBytes } = require('../../encoding')
|
||
|
||
const dd = Buffer.from('--')
|
||
const decoder = new TextDecoder()
|
||
|
||
/**
|
||
* @param {string} chars
|
||
*/
|
||
function isAsciiString (chars) {
|
||
for (let i = 0; i < chars.length; ++i) {
|
||
if ((chars.charCodeAt(i) & ~0x7F) !== 0) {
|
||
return false
|
||
}
|
||
}
|
||
return true
|
||
}
|
||
|
||
/**
|
||
* @see https://andreubotella.github.io/multipart-form-data/#multipart-form-data-boundary
|
||
* @param {string} boundary
|
||
*/
|
||
function validateBoundary (boundary) {
|
||
const length = boundary.length
|
||
|
||
// - its length is greater or equal to 27 and lesser or equal to 70, and
|
||
if (length < 27 || length > 70) {
|
||
return false
|
||
}
|
||
|
||
// - it is composed by bytes in the ranges 0x30 to 0x39, 0x41 to 0x5A, or
|
||
// 0x61 to 0x7A, inclusive (ASCII alphanumeric), or which are 0x27 ('),
|
||
// 0x2D (-) or 0x5F (_).
|
||
for (let i = 0; i < length; ++i) {
|
||
const cp = boundary.charCodeAt(i)
|
||
|
||
if (!(
|
||
(cp >= 0x30 && cp <= 0x39) ||
|
||
(cp >= 0x41 && cp <= 0x5a) ||
|
||
(cp >= 0x61 && cp <= 0x7a) ||
|
||
cp === 0x27 ||
|
||
cp === 0x2d ||
|
||
cp === 0x5f
|
||
)) {
|
||
return false
|
||
}
|
||
}
|
||
|
||
return true
|
||
}
|
||
|
||
/**
|
||
* @see https://andreubotella.github.io/multipart-form-data/#multipart-form-data-parser
|
||
* @param {Buffer} input
|
||
* @param {ReturnType<import('./data-url')['parseMIMEType']>} mimeType
|
||
*/
|
||
function multipartFormDataParser (input, mimeType) {
|
||
// 1. Assert: mimeType’s essence is "multipart/form-data".
|
||
assert(mimeType !== 'failure' && mimeType.essence === 'multipart/form-data')
|
||
|
||
const boundaryString = mimeType.parameters.get('boundary')
|
||
|
||
// 2. If mimeType’s parameters["boundary"] does not exist, return failure.
|
||
// Otherwise, let boundary be the result of UTF-8 decoding mimeType’s
|
||
// parameters["boundary"].
|
||
if (boundaryString === undefined) {
|
||
throw parsingError('missing boundary in content-type header')
|
||
}
|
||
|
||
const boundary = Buffer.from(`--${boundaryString}`, 'utf8')
|
||
|
||
// 3. Let entry list be an empty entry list.
|
||
const entryList = []
|
||
|
||
// 4. Let position be a pointer to a byte in input, initially pointing at
|
||
// the first byte.
|
||
const position = { position: 0 }
|
||
|
||
// Note: Per RFC 2046 Section 5.1.1, we must ignore anything before the
|
||
// first boundary delimiter line (preamble). Search for the first boundary.
|
||
const firstBoundaryIndex = input.indexOf(boundary)
|
||
|
||
if (firstBoundaryIndex === -1) {
|
||
throw parsingError('no boundary found in multipart body')
|
||
}
|
||
|
||
// Start parsing from the first boundary, ignoring any preamble
|
||
position.position = firstBoundaryIndex
|
||
|
||
// 5. While true:
|
||
while (true) {
|
||
// 5.1. If position points to a sequence of bytes starting with 0x2D 0x2D
|
||
// (`--`) followed by boundary, advance position by 2 + the length of
|
||
// boundary. Otherwise, return failure.
|
||
// Note: boundary is padded with 2 dashes already, no need to add 2.
|
||
if (input.subarray(position.position, position.position + boundary.length).equals(boundary)) {
|
||
position.position += boundary.length
|
||
} else {
|
||
throw parsingError('expected a value starting with -- and the boundary')
|
||
}
|
||
|
||
// 5.2. If position points to the sequence of bytes 0x2D 0x2D 0x0D 0x0A
|
||
// (`--` followed by CR LF) followed by the end of input, return entry list.
|
||
// Note: Per RFC 2046 Section 5.1.1, we must ignore anything after the
|
||
// final boundary delimiter (epilogue). Check for -- or --CRLF and return
|
||
// regardless of what follows.
|
||
if (bufferStartsWith(input, dd, position)) {
|
||
// Found closing boundary delimiter (--), ignore any epilogue
|
||
return entryList
|
||
}
|
||
|
||
// 5.3. If position does not point to a sequence of bytes starting with 0x0D
|
||
// 0x0A (CR LF), return failure.
|
||
if (input[position.position] !== 0x0d || input[position.position + 1] !== 0x0a) {
|
||
throw parsingError('expected CRLF')
|
||
}
|
||
|
||
// 5.4. Advance position by 2. (This skips past the newline.)
|
||
position.position += 2
|
||
|
||
// 5.5. Let name, filename and contentType be the result of parsing
|
||
// multipart/form-data headers on input and position, if the result
|
||
// is not failure. Otherwise, return failure.
|
||
const result = parseMultipartFormDataHeaders(input, position)
|
||
|
||
let { name, filename, contentType, encoding } = result
|
||
|
||
// 5.6. Advance position by 2. (This skips past the empty line that marks
|
||
// the end of the headers.)
|
||
position.position += 2
|
||
|
||
// 5.7. Let body be the empty byte sequence.
|
||
let body
|
||
|
||
// 5.8. Body loop: While position is not past the end of input:
|
||
// TODO: the steps here are completely wrong
|
||
{
|
||
const boundaryIndex = input.indexOf(boundary.subarray(2), position.position)
|
||
|
||
if (boundaryIndex === -1) {
|
||
throw parsingError('expected boundary after body')
|
||
}
|
||
|
||
body = input.subarray(position.position, boundaryIndex - 4)
|
||
|
||
position.position += body.length
|
||
|
||
// Note: position must be advanced by the body's length before being
|
||
// decoded, otherwise the parsing will fail.
|
||
if (encoding === 'base64') {
|
||
body = Buffer.from(body.toString(), 'base64')
|
||
}
|
||
}
|
||
|
||
// 5.9. If position does not point to a sequence of bytes starting with
|
||
// 0x0D 0x0A (CR LF), return failure. Otherwise, advance position by 2.
|
||
if (input[position.position] !== 0x0d || input[position.position + 1] !== 0x0a) {
|
||
throw parsingError('expected CRLF')
|
||
} else {
|
||
position.position += 2
|
||
}
|
||
|
||
// 5.10. If filename is not null:
|
||
let value
|
||
|
||
if (filename !== null) {
|
||
// 5.10.1. If contentType is null, set contentType to "text/plain".
|
||
contentType ??= 'text/plain'
|
||
|
||
// 5.10.2. If contentType is not an ASCII string, set contentType to the empty string.
|
||
|
||
// Note: `buffer.isAscii` can be used at zero-cost, but converting a string to a buffer is a high overhead.
|
||
// Content-Type is a relatively small string, so it is faster to use `String#charCodeAt`.
|
||
if (!isAsciiString(contentType)) {
|
||
contentType = ''
|
||
}
|
||
|
||
// 5.10.3. Let value be a new File object with name filename, type contentType, and body body.
|
||
value = new File([body], filename, { type: contentType })
|
||
} else {
|
||
// 5.11. Otherwise:
|
||
|
||
// 5.11.1. Let value be the UTF-8 decoding without BOM of body.
|
||
value = utf8DecodeBytes(Buffer.from(body))
|
||
}
|
||
|
||
// 5.12. Assert: name is a scalar value string and value is either a scalar value string or a File object.
|
||
assert(webidl.is.USVString(name))
|
||
assert((typeof value === 'string' && webidl.is.USVString(value)) || webidl.is.File(value))
|
||
|
||
// 5.13. Create an entry with name and value, and append it to entry list.
|
||
entryList.push(makeEntry(name, value, filename))
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Parses content-disposition attributes (e.g., name="value" or filename*=utf-8''encoded)
|
||
* @param {Buffer} input
|
||
* @param {{ position: number }} position
|
||
* @returns {{ name: string, value: string }}
|
||
*/
|
||
function parseContentDispositionAttribute (input, position) {
|
||
// Skip leading semicolon and whitespace
|
||
if (input[position.position] === 0x3b /* ; */) {
|
||
position.position++
|
||
}
|
||
|
||
// Skip whitespace
|
||
collectASequenceOfBytes(
|
||
(char) => char === 0x20 || char === 0x09,
|
||
input,
|
||
position
|
||
)
|
||
|
||
// Collect attribute name (token characters)
|
||
const attributeName = collectASequenceOfBytes(
|
||
(char) => isToken(char) && char !== 0x3d && char !== 0x2a, // not = or *
|
||
input,
|
||
position
|
||
)
|
||
|
||
if (attributeName.length === 0) {
|
||
return null
|
||
}
|
||
|
||
const attrNameStr = attributeName.toString('ascii').toLowerCase()
|
||
|
||
// Check for extended notation (attribute*)
|
||
const isExtended = input[position.position] === 0x2a /* * */
|
||
if (isExtended) {
|
||
position.position++ // skip *
|
||
}
|
||
|
||
// Expect = sign
|
||
if (input[position.position] !== 0x3d /* = */) {
|
||
return null
|
||
}
|
||
position.position++ // skip =
|
||
|
||
// Skip whitespace
|
||
collectASequenceOfBytes(
|
||
(char) => char === 0x20 || char === 0x09,
|
||
input,
|
||
position
|
||
)
|
||
|
||
let value
|
||
|
||
if (isExtended) {
|
||
// Extended attribute format: charset'language'encoded-value
|
||
const headerValue = collectASequenceOfBytes(
|
||
(char) => char !== 0x20 && char !== 0x0d && char !== 0x0a && char !== 0x3b, // not space, CRLF, or ;
|
||
input,
|
||
position
|
||
)
|
||
|
||
// Check for utf-8'' prefix (case insensitive)
|
||
if (
|
||
(headerValue[0] !== 0x75 && headerValue[0] !== 0x55) || // u or U
|
||
(headerValue[1] !== 0x74 && headerValue[1] !== 0x54) || // t or T
|
||
(headerValue[2] !== 0x66 && headerValue[2] !== 0x46) || // f or F
|
||
headerValue[3] !== 0x2d || // -
|
||
headerValue[4] !== 0x38 // 8
|
||
) {
|
||
throw parsingError('unknown encoding, expected utf-8\'\'')
|
||
}
|
||
|
||
// Skip utf-8'' and decode the rest
|
||
value = decodeURIComponent(decoder.decode(headerValue.subarray(7)))
|
||
} else if (input[position.position] === 0x22 /* " */) {
|
||
// Quoted string
|
||
position.position++ // skip opening quote
|
||
|
||
const quotedValue = collectASequenceOfBytes(
|
||
(char) => char !== 0x0a && char !== 0x0d && char !== 0x22, // not LF, CR, or "
|
||
input,
|
||
position
|
||
)
|
||
|
||
if (input[position.position] !== 0x22) {
|
||
throw parsingError('Closing quote not found')
|
||
}
|
||
position.position++ // skip closing quote
|
||
|
||
value = decoder.decode(quotedValue)
|
||
.replace(/%0A/ig, '\n')
|
||
.replace(/%0D/ig, '\r')
|
||
.replace(/%22/g, '"')
|
||
} else {
|
||
// Token value (no quotes)
|
||
const tokenValue = collectASequenceOfBytes(
|
||
(char) => isToken(char) && char !== 0x3b, // not ;
|
||
input,
|
||
position
|
||
)
|
||
|
||
value = decoder.decode(tokenValue)
|
||
}
|
||
|
||
return { name: attrNameStr, value }
|
||
}
|
||
|
||
/**
|
||
* @see https://andreubotella.github.io/multipart-form-data/#parse-multipart-form-data-headers
|
||
* @param {Buffer} input
|
||
* @param {{ position: number }} position
|
||
*/
|
||
function parseMultipartFormDataHeaders (input, position) {
|
||
// 1. Let name, filename and contentType be null.
|
||
let name = null
|
||
let filename = null
|
||
let contentType = null
|
||
let encoding = null
|
||
|
||
// 2. While true:
|
||
while (true) {
|
||
// 2.1. If position points to a sequence of bytes starting with 0x0D 0x0A (CR LF):
|
||
if (input[position.position] === 0x0d && input[position.position + 1] === 0x0a) {
|
||
// 2.1.1. If name is null, return failure.
|
||
if (name === null) {
|
||
throw parsingError('header name is null')
|
||
}
|
||
|
||
// 2.1.2. Return name, filename and contentType.
|
||
return { name, filename, contentType, encoding }
|
||
}
|
||
|
||
// 2.2. Let header name be the result of collecting a sequence of bytes that are
|
||
// not 0x0A (LF), 0x0D (CR) or 0x3A (:), given position.
|
||
let headerName = collectASequenceOfBytes(
|
||
(char) => char !== 0x0a && char !== 0x0d && char !== 0x3a,
|
||
input,
|
||
position
|
||
)
|
||
|
||
// 2.3. Remove any HTTP tab or space bytes from the start or end of header name.
|
||
headerName = removeChars(headerName, true, true, (char) => char === 0x9 || char === 0x20)
|
||
|
||
// 2.4. If header name does not match the field-name token production, return failure.
|
||
if (!HTTP_TOKEN_CODEPOINTS.test(headerName.toString())) {
|
||
throw parsingError('header name does not match the field-name token production')
|
||
}
|
||
|
||
// 2.5. If the byte at position is not 0x3A (:), return failure.
|
||
if (input[position.position] !== 0x3a) {
|
||
throw parsingError('expected :')
|
||
}
|
||
|
||
// 2.6. Advance position by 1.
|
||
position.position++
|
||
|
||
// 2.7. Collect a sequence of bytes that are HTTP tab or space bytes given position.
|
||
// (Do nothing with those bytes.)
|
||
collectASequenceOfBytes(
|
||
(char) => char === 0x20 || char === 0x09,
|
||
input,
|
||
position
|
||
)
|
||
|
||
// 2.8. Byte-lowercase header name and switch on the result:
|
||
switch (bufferToLowerCasedHeaderName(headerName)) {
|
||
case 'content-disposition': {
|
||
name = filename = null
|
||
|
||
// Collect the disposition type (should be "form-data")
|
||
const dispositionType = collectASequenceOfBytes(
|
||
(char) => isToken(char),
|
||
input,
|
||
position
|
||
)
|
||
|
||
if (dispositionType.toString('ascii').toLowerCase() !== 'form-data') {
|
||
throw parsingError('expected form-data for content-disposition header')
|
||
}
|
||
|
||
// Parse attributes recursively until CRLF
|
||
while (
|
||
position.position < input.length &&
|
||
input[position.position] !== 0x0d &&
|
||
input[position.position + 1] !== 0x0a
|
||
) {
|
||
const attribute = parseContentDispositionAttribute(input, position)
|
||
|
||
if (!attribute) {
|
||
break
|
||
}
|
||
|
||
if (attribute.name === 'name') {
|
||
name = attribute.value
|
||
} else if (attribute.name === 'filename') {
|
||
filename = attribute.value
|
||
}
|
||
}
|
||
|
||
if (name === null) {
|
||
throw parsingError('name attribute is required in content-disposition header')
|
||
}
|
||
|
||
break
|
||
}
|
||
case 'content-type': {
|
||
// 1. Let header value be the result of collecting a sequence of bytes that are
|
||
// not 0x0A (LF) or 0x0D (CR), given position.
|
||
let headerValue = collectASequenceOfBytes(
|
||
(char) => char !== 0x0a && char !== 0x0d,
|
||
input,
|
||
position
|
||
)
|
||
|
||
// 2. Remove any HTTP tab or space bytes from the end of header value.
|
||
headerValue = removeChars(headerValue, false, true, (char) => char === 0x9 || char === 0x20)
|
||
|
||
// 3. Set contentType to the isomorphic decoding of header value.
|
||
contentType = isomorphicDecode(headerValue)
|
||
|
||
break
|
||
}
|
||
case 'content-transfer-encoding': {
|
||
let headerValue = collectASequenceOfBytes(
|
||
(char) => char !== 0x0a && char !== 0x0d,
|
||
input,
|
||
position
|
||
)
|
||
|
||
headerValue = removeChars(headerValue, false, true, (char) => char === 0x9 || char === 0x20)
|
||
|
||
encoding = isomorphicDecode(headerValue)
|
||
|
||
break
|
||
}
|
||
default: {
|
||
// Collect a sequence of bytes that are not 0x0A (LF) or 0x0D (CR), given position.
|
||
// (Do nothing with those bytes.)
|
||
collectASequenceOfBytes(
|
||
(char) => char !== 0x0a && char !== 0x0d,
|
||
input,
|
||
position
|
||
)
|
||
}
|
||
}
|
||
|
||
// 2.9. If position does not point to a sequence of bytes starting with 0x0D 0x0A
|
||
// (CR LF), return failure. Otherwise, advance position by 2 (past the newline).
|
||
if (input[position.position] !== 0x0d && input[position.position + 1] !== 0x0a) {
|
||
throw parsingError('expected CRLF')
|
||
} else {
|
||
position.position += 2
|
||
}
|
||
}
|
||
}
|
||
|
||
/**
|
||
* @param {(char: number) => boolean} condition
|
||
* @param {Buffer} input
|
||
* @param {{ position: number }} position
|
||
*/
|
||
function collectASequenceOfBytes (condition, input, position) {
|
||
let start = position.position
|
||
|
||
while (start < input.length && condition(input[start])) {
|
||
++start
|
||
}
|
||
|
||
return input.subarray(position.position, (position.position = start))
|
||
}
|
||
|
||
/**
|
||
* @param {Buffer} buf
|
||
* @param {boolean} leading
|
||
* @param {boolean} trailing
|
||
* @param {(charCode: number) => boolean} predicate
|
||
* @returns {Buffer}
|
||
*/
|
||
function removeChars (buf, leading, trailing, predicate) {
|
||
let lead = 0
|
||
let trail = buf.length - 1
|
||
|
||
if (leading) {
|
||
while (lead < buf.length && predicate(buf[lead])) lead++
|
||
}
|
||
|
||
if (trailing) {
|
||
while (trail > 0 && predicate(buf[trail])) trail--
|
||
}
|
||
|
||
return lead === 0 && trail === buf.length - 1 ? buf : buf.subarray(lead, trail + 1)
|
||
}
|
||
|
||
/**
|
||
* Checks if {@param buffer} starts with {@param start}
|
||
* @param {Buffer} buffer
|
||
* @param {Buffer} start
|
||
* @param {{ position: number }} position
|
||
*/
|
||
function bufferStartsWith (buffer, start, position) {
|
||
if (buffer.length < start.length) {
|
||
return false
|
||
}
|
||
|
||
for (let i = 0; i < start.length; i++) {
|
||
if (start[i] !== buffer[position.position + i]) {
|
||
return false
|
||
}
|
||
}
|
||
|
||
return true
|
||
}
|
||
|
||
function parsingError (cause) {
|
||
return new TypeError('Failed to parse body as FormData.', { cause: new TypeError(cause) })
|
||
}
|
||
|
||
/**
|
||
* CTL = <any US-ASCII control character
|
||
* (octets 0 - 31) and DEL (127)>
|
||
* @param {number} char
|
||
*/
|
||
function isCTL (char) {
|
||
return char <= 0x1f || char === 0x7f
|
||
}
|
||
|
||
/**
|
||
* tspecials := "(" / ")" / "<" / ">" / "@" /
|
||
* "," / ";" / ":" / "\" / <">
|
||
* "/" / "[" / "]" / "?" / "="
|
||
* ; Must be in quoted-string,
|
||
* ; to use within parameter values
|
||
* @param {number} char
|
||
*/
|
||
function isTSpecial (char) {
|
||
return (
|
||
char === 0x28 || // (
|
||
char === 0x29 || // )
|
||
char === 0x3c || // <
|
||
char === 0x3e || // >
|
||
char === 0x40 || // @
|
||
char === 0x2c || // ,
|
||
char === 0x3b || // ;
|
||
char === 0x3a || // :
|
||
char === 0x5c || // \
|
||
char === 0x22 || // "
|
||
char === 0x2f || // /
|
||
char === 0x5b || // [
|
||
char === 0x5d || // ]
|
||
char === 0x3f || // ?
|
||
char === 0x3d // +
|
||
)
|
||
}
|
||
|
||
/**
|
||
* token := 1*<any (US-ASCII) CHAR except SPACE, CTLs,
|
||
* or tspecials>
|
||
* @param {number} char
|
||
*/
|
||
function isToken (char) {
|
||
return (
|
||
char <= 0x7f && // ascii
|
||
char !== 0x20 && // space
|
||
char !== 0x09 &&
|
||
!isCTL(char) &&
|
||
!isTSpecial(char)
|
||
)
|
||
}
|
||
|
||
module.exports = {
|
||
multipartFormDataParser,
|
||
validateBoundary
|
||
}
|