transaction.js
Rama master · réplica de lectura del repositorio original.
'use strict'
// An SMTP Transaction
const util = require('node:util')
const Notes = require('haraka-notes')
const utils = require('haraka-utils')
const message = require('haraka-email-message')
class Transaction {
constructor(uuid, cfg = {}) {
this.uuid = uuid || utils.uuid()
this.cfg = cfg
this.mail_from = null
this.rcpt_to = []
this.header_lines = []
this.data_lines = []
this.attachment_start_hooks = []
this.banner = null
this.body_filters = []
this.data_bytes = 0
this.header_pos = 0
this.found_hb_sep = false
this.body = null
this.parse_body = false
this.notes = new Notes()
this.notes.skip_plugins = []
this.header = new message.Header()
this.message_stream = new message.stream(this.cfg, this.uuid, this.header.header_list)
this.discard_data = false
this.resetting = false
this.rcpt_count = {
accept: 0,
tempfail: 0,
reject: 0,
}
this.msg_status = undefined
this.data_post_start = null
this.data_post_delay = 0
this.encoding = 'utf8'
this.mime_part_count = 0
}
ensure_body() {
if (this.body) return
this.body = new message.Body(this.header)
this.body.on('mime_boundary', () => this.incr_mime_count())
for (const hook of this.attachment_start_hooks) {
this.body.on('attachment_start', hook)
}
if (this.banner) this.body.set_banner(this.banner)
for (const o of this.body_filters) {
this.body.add_filter((ct, enc, buf) => {
if (!ct) return buf
const ct_lc = String(ct).toLowerCase().trim()
const re_match = util.types.isRegExp(o.ct_match) && o.ct_match.test(ct_lc)
const ct_begins = ct_lc.indexOf(String(o.ct_match).toLowerCase()) === 0
if (re_match || ct_begins) return o.filter(ct, enc, buf) || buf
return buf
})
}
}
// Removes the CR of a CRLF newline at the end of the buffer.
remove_final_cr(data) {
if (data.length < 2) return data
if (!Buffer.isBuffer(data)) data = Buffer.from(data)
if (data[data.length - 2] === 0x0d && data[data.length - 1] === 0x0a) {
data[data.length - 2] = 0x0a
return data.slice(0, data.length - 1)
}
return data
}
// Duplicates any '.' chars at the beginning of a line (dot-stuffing) and
// ensures all newlines are CRLF.
add_dot_stuffing_and_ensure_crlf_newlines(data) {
if (!data.length) return data
if (!Buffer.isBuffer(data)) data = Buffer.from(data)
// Make a new buffer big enough to hold two bytes for every one input
// byte. At most, we add one extra character per input byte, so this
// is always big enough. We allocate it "unsafe" (i.e. no memset) for
// speed because we're about to fill it with data, and the remainder of
// the space we don't fill will be sliced away before we return this.
const output = Buffer.allocUnsafe(data.length * 2)
let output_pos = 0
let input_pos = 0
let next_dot = data.indexOf(0x2e)
let next_lf = data.indexOf(0x0a)
while (next_dot !== -1 || next_lf !== -1) {
const run_end = next_dot !== -1 && (next_lf === -1 || next_dot < next_lf) ? next_dot : next_lf
// Copy up to whichever comes first, '.' or '\n' (but don't
// copy the '.' or '\n' itself).
data.copy(output, output_pos, input_pos, run_end)
output_pos += run_end - input_pos
if (data[run_end] === 0x2e && (run_end === 0 || data[run_end - 1] === 0x0a)) {
// Replace /^\./ with '..'
output[output_pos++] = 0x2e
} else if (data[run_end] === 0x0a && (run_end === 0 || data[run_end - 1] !== 0x0d)) {
// Replace /\r?\n/ with '\r\n'
output[output_pos++] = 0x0d
}
output[output_pos++] = data[run_end]
input_pos = run_end + 1
if (run_end === next_dot) {
next_dot = data.indexOf(0x2e, input_pos)
} else {
next_lf = data.indexOf(0x0a, input_pos)
}
}
if (input_pos < data.length) {
data.copy(output, output_pos, input_pos)
output_pos += data.length - input_pos
}
return output.slice(0, output_pos)
}
add_data(line) {
if (typeof line === 'string') {
// This shouldn't ever happen.
line = Buffer.from(line, this.encoding)
}
// is this the end of headers line?
if (this.header_pos === 0 && (line[0] === 0x0a || (line[0] === 0x0d && line[1] === 0x0a))) {
this.header.parse(this.header_lines)
this.header_pos = this.header.header_list ? this.header.header_list.length : -1
this.found_hb_sep = true
if (this.parse_body) this.ensure_body()
} else if (this.header_pos === 0) {
// Build up headers
if (this.header_lines.length < (this.cfg?.headers?.max_lines || 1000)) {
// De-stuff one leading dot for the parsed header value (RFC 5321
// §4.5.2), but keep the original dot-stuffed `line` for message_stream
const header_line = line[0] === 0x2e ? line.slice(1) : line
this.header_lines.push(header_line.toString(this.encoding).replace(/\r\n$/, '\n'))
}
} else if (this.parse_body) {
this.ensure_body()
let new_line = line
if (new_line[0] === 0x2e) new_line = new_line.slice(1) // Strip leading "."
line = this.add_dot_stuffing_and_ensure_crlf_newlines(this.body.parse_more(this.remove_final_cr(new_line)))
if (!line.length) return // buffering for banners
}
if (!this.discard_data) this.message_stream.add_line(line)
}
end_data(cb) {
if (!this.found_hb_sep && this.header_lines.length) {
// Headers not parsed yet - must be a busted email
// Strategy: Find the first line that doesn't look like a header.
// Treat anything before that as headers, anything after as body.
let header_pos = 0
for (let i = 0; i < this.header_lines.length; i++) {
// Anything that doesn't match a header or continuation
if (!/^(?:([^\s:]*):\s*([\s\S]*)$|[ \t])/.test(this.header_lines[i])) {
break
}
header_pos = i
}
const body_lines = this.header_lines.splice(header_pos + 1)
this.header.parse(this.header_lines)
this.header_pos = this.header.header_list ? this.header.header_list.length : -1
this.found_hb_sep = true
// We MUST add an empty line to the message_stream so that it knows
// where the headers end. Otherwise it skips everything.
if (!this.discard_data) this.message_stream.add_line(Buffer.from('\r\n'))
if (this.parse_body) {
this.ensure_body()
for (const bodyLine of body_lines) {
this.body.parse_more(bodyLine)
}
}
// header_lines holds de-stuffed values for the header parser; a line
// reclassified as body must go back to wire form
for (const bodyLine of body_lines) {
if (this.discard_data) continue
const wire = this.add_dot_stuffing_and_ensure_crlf_newlines(bodyLine.replace(/\r?\n?$/, '\n'))
this.message_stream.add_line(wire)
}
}
if (this.header_pos && this.parse_body) {
const line = this.add_dot_stuffing_and_ensure_crlf_newlines(this.body.parse_end())
if (line.length) {
this.body.force_end()
if (!this.discard_data) this.message_stream.add_line(line)
}
}
if (this.discard_data) {
cb()
} else {
this.message_stream.add_line_end(cb)
}
}
add_header(key, value) {
this.header.add_end(key, value)
if (this.found_hb_sep) this.reset_headers()
}
add_leading_header(key, value) {
this.header.add(key, value)
if (this.found_hb_sep) this.reset_headers()
}
reset_headers() {
this.header_pos = this.header.header_list ? this.header.header_list.length : -1
}
remove_header(key) {
this.header.remove(key)
if (this.found_hb_sep) this.reset_headers()
}
attachment_hooks(start) {
this.parse_body = true
this.attachment_start_hooks.push(start)
}
set_banner(text, html) {
// throw "transaction.set_banner is currently non-functional";
this.parse_body = true
if (!html) {
html = text.replace(/\n/g, '<br/>\n')
}
this.banner = [text, html]
}
add_body_filter(ct_match, filter) {
this.parse_body = true
this.body_filters.push({ ct_match, filter })
if (this.body) {
this.body.add_filter((ct, enc, buf) => {
if (!ct) return buf
const ct_lc = String(ct).toLowerCase().trim()
const re_match = util.types.isRegExp(ct_match) && ct_match.test(ct_lc)
const ct_begins = ct_lc.indexOf(String(ct_match).toLowerCase()) === 0
if (re_match || ct_begins) return filter(ct, enc, buf) || buf
return buf
})
}
}
incr_mime_count() {
this.mime_part_count++
}
}
exports.Transaction = Transaction
exports.createTransaction = (uuid, cfg) => {
return new Transaction(uuid, cfg)
}