haraka-email-message
Version:
Haraka email message
949 lines (818 loc) • 26.4 kB
JavaScript
const events = require('events')
const config = require('haraka-config')
const libmime = require('libmime')
const libqp = require('libqp')
const Stream = require('stream')
const Iconv = require('iconv').Iconv
let logger
try {
logger = require('./logger')
} catch (ignore) {
logger = {
lognotice: console.log,
logerror: console.error,
logwarn: console.error,
}
}
const buf_siz = config.get('mailparser.bufsize') || 65536
// An RFC 2822 email header parser
/* eslint no-control-regex: 0 */
class Header {
constructor(options) {
this.headers = {}
this.headers_decoded = {}
this.header_list = []
this.options = options
}
parse(lines) {
for (const line of lines) {
if (/^[ \t]/.test(line)) {
// continuation
this.header_list[this.header_list.length - 1] += line
} else {
this.header_list.push(line)
}
}
for (const header of this.header_list) {
const match = header.match(/^([^\s:]*):\s*([\s\S]*)$/)
if (match) {
const key = match[1].toLowerCase()
const val = match[2]
this._add_header(key, val, 'push')
} else {
logger.lognotice(`Header did not look right: ${header}`)
}
}
// Now add decoded versions
for (const key of Object.keys(this.headers)) {
for (const val of this.headers[key]) {
this._add_header_decode(key, val, 'push')
}
}
}
decode_header(val) {
// Fold continuations
val = val.replace(/\r?\n/g, '')
const rfc2231_params = {
kv: {},
keys: {},
cur_key: '',
cur_enc: '',
cur_lang: '', // Secondary languages are ignored for our purposes
}
val = _decode_rfc2231(rfc2231_params, val)
// strip 822 comments in the most basic way - does not support nested comments
// val = val.replace(/\([^\)]*\)/, '');
if (Iconv && !/^[\x00-\x7f]*$/.test(val)) {
// 8 bit values in the header
const matches = /\bcharset\s*=\s*["']?([\w_-]*)/.exec(
this.get('content-type'),
)
if (matches && !/UTF-?8/i.test(matches[1])) {
const encoding = matches[1]
const source = Buffer.from(val, 'binary')
val = try_convert(source, encoding).toString()
}
}
if (!/=\?/.test(val)) {
// no encoded stuff
return val
}
return (
val
// strip whitespace between encoded-words, rfc 2047 6.2
.replace(/(=\?.+?\?=)\s+(?==\?.+?\?=)/g, '$1')
// decode each encoded match
.replace(
/=\?([\w_-]+)(\*[\w_-]+)?\?([bqBQ])\?([\s\S]*?)\?=/g,
_decode_header,
)
)
}
get(key) {
return (this.headers[key.toLowerCase()] || []).join('\n')
}
get_all(key) {
return Object.freeze([...(this.headers[key.toLowerCase()] || [])])
}
get_decoded(key) {
return (this.headers_decoded[key.toLowerCase()] || []).join('\n')
}
remove(key) {
key = key.toLowerCase()
delete this.headers[key]
delete this.headers_decoded[key]
this._remove_more(key)
}
_remove_more(key) {
const key_len = key.length
for (let i = 0, l = this.header_list.length; i < l; i++) {
if (
this.header_list[i].substring(0, key_len + 1).toLowerCase() ===
`${key}:`
) {
this.header_list.splice(i, 1)
return this._remove_more(key)
}
}
}
add(key, value) {
if (!key) key = 'X-Haraka-Blank'
value = value.replace(/(\r?\n)*$/, '')
if (/[^\x00-\x7f]/.test(value)) {
value = libmime.encodeWords(value, 'Q')
}
this._add_header(key.toLowerCase(), value, 'unshift')
this._add_header_decode(key.toLowerCase(), value, 'unshift')
this.header_list.unshift(`${key}: ${value}\n`)
}
_add_header(key, value, method) {
this.headers[key] = this.headers[key] || []
this.headers[key][method](value)
}
_add_header_decode(key, value, method) {
const val = this.decode_header(value)
// console.log(key + ': ' + val);
this.headers_decoded[key] = this.headers_decoded[key] || []
this.headers_decoded[key][method](val)
}
add_end(key, value) {
if (!key) key = 'X-Haraka-Blank'
value = value.replace(/(\r?\n)*$/, '')
if (/[^\x00-\x7f]/.test(value)) {
value = libmime.encodeWords(value, 'Q')
}
this._add_header(key.toLowerCase(), value, 'push')
this._add_header_decode(key.toLowerCase(), value, 'push')
this.header_list.push(`${key}: ${value}\n`)
}
lines() {
return Object.freeze([...this.header_list])
}
toString() {
return this.header_list.join('\n')
}
}
function try_convert(data, encoding) {
try {
const converter = new Iconv(encoding, 'UTF-8')
data = converter.convert(data)
} catch (err) {
// TODO: raise a flag for this for possible scoring
logger.logwarn(
`initial iconv conversion from ${encoding} to UTF-8 failed: ${err.message}`,
)
if (err.code !== 'EINVAL') {
try {
const converter = new Iconv(encoding, 'UTF-8//TRANSLIT//IGNORE')
data = converter.convert(data)
} catch (e) {
logger.logerror(`iconv from ${encoding} to UTF-8 failed: ${e.message}`)
}
}
}
return data
}
function _decode_header(matched, encoding, lang, cte, data) {
cte = cte.toUpperCase()
switch (cte) {
case 'Q':
data = libqp.decode(data.replace(/_/g, ' '))
break
case 'B':
data = Buffer.from(data, 'base64')
break
default:
logger.logerror(`Invalid header encoding type: ${cte}`)
}
// convert with iconv if encoding != UTF-8
if (Iconv && !/UTF-?8/i.test(encoding)) {
data = try_convert(data, encoding)
}
return data.toString()
}
function _decode_rfc2231(params, str) {
_parse_rfc2231(params, str)
for (const key in params.keys) {
str += ` ${key}="`
/* eslint no-constant-condition: 0 */
let merged = ''
for (let i = 0; true; i++) {
const _key = `${key}*${i}`
const _val = params.kv[_key]
if (_val === undefined) break
merged += _val
}
try {
merged = decodeURIComponent(merged)
} catch (e) {
logger.logerror(`Decode header failed: ${key}: ${merged}`)
}
merged = params.cur_enc ? try_convert(merged, params.cur_enc) : merged
str += `${merged}";`
}
return str
}
function _parse_rfc2231(params, str) {
/*
To explain the regexp below, the params are:
parameter := attribute "=" value
attribute := token
; Matching of attributes
; is ALWAYS case-insensitive.
token := 1*<any (US-ASCII) CHAR except SPACE, CTLs,
or tspecials>
tspecials := "(" / ")" / "<" / ">" / "@" /
"," / ";" / ":" / "\" / <">
"/" / "[" / "]" / "?" / "="
; Must be in quoted-string,
; to use within parameter values
*/
const sub_matches =
/(([!#$%&'*+.0-9A-Zdiff^_`a-z{|}~-]*)\*)(\d*)=(\s*".*?[^\\]";?|\S*)/.exec(
str,
)
if (!sub_matches) {
return
}
const key = sub_matches[1]
let key_actual = sub_matches[2]
let key_id = sub_matches[3] || '0'
let value = sub_matches[4].replace(/;$/, '')
str = str.replace(sub_matches[0], '') // strip it out, so we move to next
const key_extract = /^(.*?)(\*(\d+)\*)$/.exec(key)
if (key_extract) {
key_actual = key_extract[1]
key_id = key_extract[3]
}
const quote = /^\s*"(.*)"$/.exec(value)
if (quote) {
value = quote[1]
}
const lang_match = /^(.*?)'(.*?)'(.*)/.exec(value)
if (lang_match) {
if (key_actual == params.cur_key && lang_match[2] != params.cur_lang) {
return _parse_rfc2231(params, str) // same key, different lang, throw it away
}
params.cur_enc = lang_match[1]
params.cur_lang = lang_match[2]
value = lang_match[3]
} else if (key_actual != params.cur_key) {
params.cur_lang = ''
params.cur_enc = ''
}
params.cur_key = key_actual
params.keys[key_actual] = ''
params.kv[`${key_actual}*${key_id}`] = value
return _parse_rfc2231(params, str) // Get next one
}
// Mail Body Parser
class Body extends events.EventEmitter {
constructor(header, options) {
super()
this.header = header || new Header()
this.header_lines = []
this.is_html = false
this.options = options || {}
this.filters = []
this.bodytext = ''
// Caution: slice before using! We build up data in this buffer, and
// it always has extra space at the end. Use
// this.body_text_encoded.slice(0, this.body_text_encoded_pos).
this.body_text_encoded = Buffer.alloc(buf_siz)
this.body_text_encoded_pos = 0
this.body_encoding = null
this.boundary = null
this.ct = null
this.decode_function = null
this.children = [] // if multipart
this.state = 'start'
this.buf = Buffer.alloc(buf_siz)
this.buf_fill = 0
this.decode_accumulator = ''
this.decode_qp = (line) => libqp.decode(line.toString())
this.decode_7bit = this.decode_8bit
}
add_filter(filter) {
this.filters.push(filter)
}
set_banner(banners) {
this.add_filter((ct, enc, buf, cd) =>
insert_banner(ct, enc, buf, cd, banners),
)
}
parse_more(line) {
// Ensure we're working in buffers, for the tests (transaction should
// always pass buffers).
if (!Buffer.isBuffer(line)) line = Buffer.from(line)
return this[`parse_${this.state}`](line)
}
parse_child(line) {
const line_string = line.toString()
// check for MIME boundary
if (
line_string.substr(0, this.boundary.length + 2) === `--${this.boundary}`
) {
line = this.children[this.children.length - 1].parse_end(line)
if (line_string.substr(this.boundary.length + 2, 2) === '--') {
// end
this.state = 'end'
} else {
this.emit('mime_boundary', line_string)
const bod = new Body(new Header(), this.options)
for (const ln of [
'attachment_start',
'attachment_data',
'attachment_end',
'mime_boundary',
]) {
for (const cb of this.listeners(ln)) {
bod.on(ln, cb)
}
}
for (const f of this.filters) {
bod.add_filter(f)
}
this.children.push(bod)
bod.state = 'headers'
}
return line
}
// Pass data into last child
return this.children[this.children.length - 1].parse_more(line)
}
parse_headers(line) {
const line_string = line.toString()
if (/^\s*$/.test(line_string)) {
// end of headers
this.header.parse(this.header_lines)
delete this.header_lines
this.state = 'start'
} else {
this.header_lines.push(line_string)
}
return line
}
parse_start(line) {
const ct = this.header.get_decoded('content-type') || 'text/plain'
let enc = this.header.get_decoded('content-transfer-encoding') || '8bit'
const cd = this.header.get_decoded('content-disposition') || ''
if (/text\/html/i.test(ct)) {
this.is_html = true
}
enc = enc.toLowerCase().split('\n').pop().trim()
if (!enc.match(/^base64|quoted-printable|[78]bit$/i)) {
logger.logwarn(`Invalid CTE on email: ${enc}, using 8bit`)
enc = '8bit'
}
enc = enc.replace(/^quoted-printable$/i, 'qp')
this.decode_function = this[`decode_${enc}`]
if (!this.decode_function) {
logger.logerror(`No decode function found for: ${enc}`)
this.decode_function = this.decode_8bit
}
this.ct = ct
const buildRegex = (key) =>
new RegExp(`${key}\\s*=\\s*"([^"]+)"|${key}\\s*=\\s*"?([^";]+)"?`, 'i')
const matchKey = (test, key) =>
test.match(buildRegex(key))?.filter((item) => item)
let match
if (/^(?:text|message)\//i.test(ct) && !/^attachment/i.test(cd)) {
this.state = 'body'
} else if (/^multipart\//i.test(ct)) {
match = matchKey(ct, 'boundary')
this.boundary = match ? match[1] : ''
this.state = 'multipart_preamble'
} else {
match = matchKey(cd, 'name')
if (!match) {
match = matchKey(ct, 'name')
}
const filename = match ? match[1] : ''
this.attachment_stream = exports.createAttachmentStream(this.header)
this.emit('attachment_start', ct, filename, this, this.attachment_stream)
this.buf_fill = 0
this.state = 'attachment'
}
return this[`parse_${this.state}`](line)
}
_empty_filter(ct, enc, cd) {
let new_buf = Buffer.from('')
for (const filter of this.filters) {
new_buf = filter(ct, enc, new_buf, cd) || new_buf
}
return new_buf
}
_emit_buf_fill() {
if (this.buf_fill > 0) {
// see below for why we create a new buffer here.
const to_emit = Buffer.alloc(this.buf_fill)
this.buf.copy(to_emit, 0, 0, this.buf_fill)
this.attachment_stream.emit_data(to_emit)
this.buf_fill = 0
}
}
force_end() {
if (this.state === 'attachment') {
this._emit_buf_fill()
this.attachment_stream.emit_end(true)
}
}
parse_end(line) {
if (!line) {
line = Buffer.from('')
}
if (this.state === 'attachment') {
this._emit_buf_fill()
this.attachment_stream.emit_end()
}
const ct = this.header.get_decoded('content-type') || 'text/plain'
let enc = 'UTF-8'
let pre_enc = ''
const matches = /\bcharset\s*=\s*(?:"|3D|')?([\w_-]*)(?:"|3D|')?/.exec(ct)
if (matches) {
pre_enc = matches[1].trim()
if (pre_enc.length > 0) {
enc = pre_enc
}
}
this.body_encoding = enc
const cd = this.header.get_decoded('content-disposition') || ''
if (!this.body_text_encoded_pos) {
// nothing to decode
return Buffer.concat([
this._empty_filter(ct, enc, cd) || Buffer.from(''),
line,
])
}
if (this.bodytext.length !== 0) return line // already decoded?
let buf = this.decode_function(
this.body_text_encoded.slice(0, this.body_text_encoded_pos),
)
if (this.filters.length) {
// up until this point we've returned '' for line, so now we run
// the filters and return the whole lot as one line, re-encoded using
// whatever encoding scheme we used to decode it.
let new_buf = buf
for (const filter of this.filters) {
new_buf = filter(ct, enc, new_buf) || new_buf
}
// convert back to base_64 or QP if required:
if (this.decode_function === this.decode_qp) {
line = Buffer.from(`${libqp.wrap(libqp.encode(new_buf))}\n${line}`)
} else if (this.decode_function === this.decode_base64) {
line = Buffer.from(
new_buf.toString('base64').replace(/(.{1,76})/g, '$1\n') + line,
)
} else {
line = Buffer.concat([new_buf, line])
}
buf = new_buf
}
// convert the buffer to UTF-8, stored in this.bodytext
this.try_iconv(buf, enc)
// delete this.body_text_encoded;
return line
}
try_iconv(buf, enc) {
if (!Iconv) {
this.body_encoding = 'no_iconv'
this.bodytext = buf.toString()
return
}
if (/UTF-?8/i.test(enc)) {
this.bodytext = buf.toString()
return
}
try {
const converter = new Iconv(enc, 'UTF-8')
this.bodytext = converter.convert(buf).toString()
} catch (err) {
logger.logwarn(
`initial iconv conversion from ${enc} to UTF-8 failed: ${err.message}`,
)
this.body_encoding = `broken//${enc}`
// EINVAL is returned when the encoding type is not recognized/supported (e.g. ANSI_X3)
if (err.code !== 'EINVAL') {
// Perform the conversion again, but ignore any errors
try {
const converter = new Iconv(enc, 'UTF-8//TRANSLIT//IGNORE')
this.bodytext = converter.convert(buf).toString()
} catch (e) {
logger.logwarn(
`iconv conversion from ${enc} to UTF-8 failed: ${e.message}`,
)
this.bodytext = buf.toString()
}
}
}
}
parse_body(line) {
if (!Buffer.isBuffer(line)) line = Buffer.from(line)
// Grow the body_text_encoded buffer if we need more space. Doing this
// instead of constant Buffer.concat()s means we allocate/copy way less
// often.
if (
this.body_text_encoded_pos + line.length >
this.body_text_encoded.length
) {
let new_size = this.body_text_encoded.length * 2
while (this.body_text_encoded_pos + line.length > new_size) new_size *= 2
this.body_text_encoded = Buffer.alloc(
new_size,
this.body_text_encoded.slice(0, this.body_text_encoded_pos),
)
}
line.copy(this.body_text_encoded, this.body_text_encoded_pos)
this.body_text_encoded_pos += line.length
if (this.filters.length) return ''
return line
}
parse_multipart_preamble(line) {
if (!this.boundary) return line
const line_string = line.toString()
if (
line_string.substr(0, this.boundary.length + 2) === `--${this.boundary}`
) {
if (line_string.substr(this.boundary.length + 2, 2) === '--') {
// end
} else {
// next section
this.emit('mime_boundary', line_string)
const bod = new Body(new Header(), this.options)
for (const ln of ['attachment_start', 'mime_boundary']) {
for (const cb of this.listeners(ln)) {
bod.on(ln, cb)
}
}
for (const f of this.filters) {
bod.add_filter(f)
}
this.children.push(bod)
bod.state = 'headers'
this.state = 'child'
}
return line
}
return line
}
parse_attachment(line) {
const line_string = line.toString()
if (this.boundary) {
if (
line_string.substr(0, this.boundary.length + 2) === `--${this.boundary}`
) {
if (line_string.substr(this.boundary.length + 2, 2) === '--') {
// end
} else {
// next section
this.state = 'headers'
}
return line
}
}
const buf = this.decode_function(line)
if (buf.length + this.buf_fill > buf_siz) {
// now we have to create a new buffer, because if we write this out
// using async code, it will get overwritten under us. Creating a new
// buffer eliminates that problem (at the expense of a malloc and a
// memcpy())
const to_emit = Buffer.alloc(this.buf_fill)
this.buf.copy(to_emit, 0, 0, this.buf_fill)
this.attachment_stream.emit_data(to_emit)
if (buf.length > buf_siz) {
// this is an unusual case - the base64/whatever data is larger
// than our buffer size, so we just emit it and reset the counter.
this.attachment_stream.emit_data(buf)
this.buf_fill = 0
} else {
buf.copy(this.buf)
this.buf_fill = buf.length
}
} else {
buf.copy(this.buf, this.buf_fill)
this.buf_fill += buf.length
}
return line
}
decode_base64(line) {
// Remove all whitespace (such as newlines and errant spaces) from base64
// before combining it with any previously unprocessed data.
let to_process =
this.decode_accumulator + line.toString().trim().replace(/[\s]+/g, '')
// Sometimes base64 data lines will not be aligned with
// byte boundaries. This is because each char in base64
// represents 6 bits. 24 is the LCM between 6 and 8 bits.
// (i.e. 4 * 6-bit chars === 3 * bytes)
// As a result, 24 bits is our word boundary for base64.
// Failure to align here will result in truncated/incorrect
// node Buffers later on.
// Walk back from the toProcess.length to the first
// position that aligns with a 24-bit boundary.
const emit_length = to_process.length - (to_process.length % 4)
if (emit_length > 0) {
const emit_now = to_process.substring(0, emit_length)
this.decode_accumulator = to_process.substring(emit_length)
return Buffer.from(emit_now, 'base64')
} else {
this.decode_accumulator = ''
// This is the end of the base64 data, we don't really have enough bits
// to fill up the bytes, but that's because we're on the last line, and ==
// might have been elided.
// In order to prevent any weird boundary issues, we'll re-pad
// the string if there's any data left. As above, our target
// is a 24-bit boundary, pad to 4 characters.
while (to_process.length > 0 && to_process.length < 4) {
to_process += '='
}
return Buffer.from(to_process, 'base64')
}
}
decode_8bit(line) {
return Buffer.from(line, 'binary')
}
}
exports.Body = Body
exports.Header = Header
exports.stream = require('haraka-message-stream')
function _get_html_insert_position(buf) {
// otherwise, if we return -1 then the buf.copy will die with
// RangeError: out of range index
if (buf.length === 0) return 0
// TODO: consider re-writing this to go backwards from the end
for (let i = 0, l = buf.length; i < l; i++) {
if (buf[i] === 60 && buf[i + 1] === 47) {
// found: "</"
if (
(buf[i + 2] === 98 || buf[i + 2] === 66) && // "b" or "B"
(buf[i + 3] === 111 || buf[i + 3] === 79) && // "o" or "O"
(buf[i + 4] === 100 || buf[i + 4] === 68) && // "d" or "D"
(buf[i + 5] === 121 || buf[i + 5] === 89) && // "y" or "Y"
buf[i + 6] === 62
) {
// matched </body>
return i
}
if (
(buf[i + 2] === 104 || buf[i + 2] === 72) && // "h" or "H"
(buf[i + 3] === 116 || buf[i + 3] === 84) && // "t" or "T"
(buf[i + 4] === 109 || buf[i + 4] === 77) && // "m" or "M"
(buf[i + 5] === 108 || buf[i + 5] === 76) && // "l" or "L"
buf[i + 6] === 62
) {
// matched </html>
return i
}
}
}
return buf.length - 1 // default is at the end
}
function insert_banner(ct, enc, buf, cd, banners) {
if (!banners || !/^text\//i.test(ct) || /^attachment/i.test(cd)) {
return
}
const is_html = /text\/html/i.test(ct)
// First we convert the banner to the same encoding as the buf
const banner_str = banners[is_html ? 1 : 0]
let banner_buf = null
if (Iconv) {
try {
const converter = new Iconv('UTF-8', `${enc}//IGNORE`)
banner_buf = converter.convert(banner_str)
} catch (err) {
logger.logerror(`iconv conversion of banner to ${enc} failed: ${err}`)
}
}
if (!banner_buf) {
banner_buf = Buffer.from(banner_str)
}
// Allocate a new buffer: (7 or 2 is <P>...</P> vs \n...\n - correct that if you change those!)
const new_buf = Buffer.alloc(
buf.length + banner_buf.length + (is_html ? 7 : 2),
)
// Now we find where to insert it and combine it with the original buf:
if (is_html) {
let insert_pos = _get_html_insert_position(buf)
// copy start of buf into new_buf
buf.copy(new_buf, 0, 0, insert_pos)
// add in <P>
new_buf[insert_pos++] = 60
new_buf[insert_pos++] = 80
new_buf[insert_pos++] = 62
// copy all of banner into new_buf
banner_buf.copy(new_buf, insert_pos)
// add in </P>
new_buf[banner_buf.length + insert_pos++] = 60
new_buf[banner_buf.length + insert_pos++] = 47
new_buf[banner_buf.length + insert_pos++] = 80
new_buf[banner_buf.length + insert_pos++] = 62
// copy remainder of buf into new_buf, if there is buf remaining
if (buf.length > insert_pos - 7) {
buf.copy(new_buf, insert_pos + banner_buf.length, insert_pos - 7)
}
} else {
buf.copy(new_buf)
new_buf[buf.length] = 10 // \n
banner_buf.copy(new_buf, buf.length + 1)
new_buf[buf.length + banner_buf.length + 1] = 10 // \n
}
return new_buf
}
class AttachmentStream extends Stream {
constructor(header) {
super()
this.header = header
this.encoding = null
this.paused = false
this.end_emitted = false
this.connection = null
this.buffer = []
}
emit_data(data) {
// console.log("YYY: DATA emit");
if (this.paused) {
return this.buffer.push(data)
}
if (this.encoding) {
this.emit('data', data.toString(this.encoding))
} else {
this.emit('data', data)
}
}
emit_end(force) {
if (this.paused && !force) {
// console.log("YYY: end emit (cache)");
this.end_emitted = true
} else {
// console.log("YYY: end emit");
if (this.buffer.length > 0) {
while (this.buffer.length > 0) {
// Don't use this.emit_data() here because we don't want to
// re-buffer the data we're trying to emit, when we're
// paused and forcing the end.
const data = this.buffer.shift()
if (this.encoding) {
this.emit('data', data.toString(this.encoding))
} else {
this.emit('data', data)
}
}
}
this.emit('end')
}
}
pipe(dest, options) {
this.paused = false
const pipe = Stream.prototype.pipe.call(this, dest, options)
dest.on('drain', () => {
// console.log("YYY: DRAIN!!!");
if (this.paused) this.resume()
})
dest.on('end', () => {
// console.log("YYY: END!!");
if (this.paused) this.resume()
})
dest.on('close', () => {
// console.log("YYY: CLOSE!!");
if (this.paused) this.resume()
})
return pipe
}
setEncoding(enc) {
if (enc !== 'binary') {
throw 'Unable to set encoding to anything other than binary'
}
this.encoding = enc
}
pause() {
// console.log("YYY: PAUSE!!");
this.paused = true
if (this.connection) {
// console.log("YYYY: Backpressure pause");
this.connection.pause()
}
}
resume() {
// console.log("YYY: RESUME!!");
if (this.connection) {
// console.log("YYYY: Backpressure resume");
this.connection.resume()
}
this.paused = false
if (this.buffer.length) {
while (this.paused === false && this.buffer.length > 0) {
this.emit_data(this.buffer.shift())
}
if (this.buffer.length === 0 && this.end_emitted) {
this.emit('end')
}
} else if (this.end_emitted) {
this.emit('end')
}
}
destroy() {
// console.log("YYYY: Stream destroyed");
}
}
exports.createAttachmentStream = (header) => new AttachmentStream(header)