923 lines
33 KiB
JavaScript
923 lines
33 KiB
JavaScript
/* eslint no-control-regex: 0, no-div-regex: 0, quotes: 0 */
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'use strict';
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const libcharset = require('./charset');
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const libbase64 = require('libbase64');
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const libqp = require('libqp');
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const mimetypes = require('./mimetypes');
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const STAGE_KEY = 0x1001;
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const STAGE_VALUE = 0x1002;
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class Libmime {
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constructor(config) {
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this.config = config || {};
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}
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/**
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* Checks if a value is plaintext string (uses only printable 7bit chars)
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*
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* @param {String} value String to be tested
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* @returns {Boolean} true if it is a plaintext string
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*/
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isPlainText(value) {
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if (typeof value !== 'string' || /[\x00-\x08\x0b\x0c\x0e-\x1f\u0080-\uFFFF]/.test(value)) {
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return false;
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} else {
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return true;
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}
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}
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/**
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* Checks if a multi line string containes lines longer than the selected value.
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*
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* Useful when detecting if a mail message needs any processing at all –
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* if only plaintext characters are used and lines are short, then there is
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* no need to encode the values in any way. If the value is plaintext but has
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* longer lines then allowed, then use format=flowed
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*
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* @param {Number} lineLength Max line length to check for
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* @returns {Boolean} Returns true if there is at least one line longer than lineLength chars
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*/
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hasLongerLines(str, lineLength) {
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return new RegExp('^.{' + (lineLength + 1) + ',}', 'm').test(str);
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}
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/**
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* Decodes a string from a format=flowed soft wrapping.
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*
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* @param {String} str Plaintext string with format=flowed to decode
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* @param {Boolean} [delSp] If true, delete leading spaces (delsp=yes)
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* @return {String} Mime decoded string
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*/
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decodeFlowed(str, delSp) {
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str = (str || '').toString();
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return (
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str
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.split(/\r?\n/)
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// remove soft linebreaks
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// soft linebreaks are added after space symbols
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.reduce((previousValue, currentValue) => {
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if (/ $/.test(previousValue) && !/(^|\n)-- $/.test(previousValue)) {
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if (delSp) {
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// delsp adds space to text to be able to fold it
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// these spaces can be removed once the text is unfolded
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return previousValue.slice(0, -1) + currentValue;
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} else {
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return previousValue + currentValue;
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}
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} else {
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return previousValue + '\n' + currentValue;
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}
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})
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// remove whitespace stuffing
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// http://tools.ietf.org/html/rfc3676#section-4.4
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.replace(/^ /gm, '')
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);
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}
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/**
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* Adds soft line breaks to content marked with format=flowed to
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* ensure that no line in the message is never longer than lineLength
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*
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* @param {String} str Plaintext string that requires wrapping
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* @param {Number} [lineLength=76] Maximum length of a line
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* @return {String} String with forced line breaks
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*/
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encodeFlowed(str, lineLength) {
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lineLength = lineLength || 76;
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let flowed = [];
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str.split(/\r?\n/).forEach(line => {
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flowed.push(
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this.foldLines(
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line
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// space stuffing http://tools.ietf.org/html/rfc3676#section-4.2
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.replace(/^( |From|>)/gim, ' $1'),
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lineLength,
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true
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)
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);
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});
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return flowed.join('\r\n');
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}
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/**
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* Encodes a string or an Buffer to an UTF-8 MIME Word (rfc2047)
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*
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* @param {String|Buffer} data String to be encoded
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* @param {String} mimeWordEncoding='Q' Encoding for the mime word, either Q or B
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* @param {Number} [maxLength=0] If set, split mime words into several chunks if needed
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* @return {String} Single or several mime words joined together
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*/
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encodeWord(data, mimeWordEncoding, maxLength) {
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mimeWordEncoding = (mimeWordEncoding || 'Q')
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.toString()
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.toUpperCase()
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.trim()
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.charAt(0);
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maxLength = maxLength || 0;
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let encodedStr;
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let toCharset = 'UTF-8';
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if (maxLength && maxLength > 7 + toCharset.length) {
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maxLength -= 7 + toCharset.length;
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}
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if (mimeWordEncoding === 'Q') {
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// https://tools.ietf.org/html/rfc2047#section-5 rule (3)
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encodedStr = libqp.encode(data).replace(/[^a-z0-9!*+\-/=]/gi, chr => {
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let ord = chr
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.charCodeAt(0)
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.toString(16)
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.toUpperCase();
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if (chr === ' ') {
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return '_';
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} else {
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return '=' + (ord.length === 1 ? '0' + ord : ord);
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}
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});
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} else if (mimeWordEncoding === 'B') {
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encodedStr = typeof data === 'string' ? data : libbase64.encode(data);
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maxLength = maxLength ? Math.max(3, ((maxLength - (maxLength % 4)) / 4) * 3) : 0;
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}
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if (maxLength && (mimeWordEncoding !== 'B' ? encodedStr : libbase64.encode(data)).length > maxLength) {
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if (mimeWordEncoding === 'Q') {
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encodedStr = this.splitMimeEncodedString(encodedStr, maxLength).join('?= =?' + toCharset + '?' + mimeWordEncoding + '?');
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} else {
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// RFC2047 6.3 (2) states that encoded-word must include an integral number of characters, so no chopping unicode sequences
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let parts = [];
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let lpart = '';
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for (let i = 0, len = encodedStr.length; i < len; i++) {
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let chr = encodedStr.charAt(i);
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// check if we can add this character to the existing string
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// without breaking byte length limit
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if (Buffer.byteLength(lpart + chr) <= maxLength || i === 0) {
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lpart += chr;
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} else {
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// we hit the length limit, so push the existing string and start over
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parts.push(libbase64.encode(lpart));
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lpart = chr;
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}
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}
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if (lpart) {
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parts.push(libbase64.encode(lpart));
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}
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if (parts.length > 1) {
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encodedStr = parts.join('?= =?' + toCharset + '?' + mimeWordEncoding + '?');
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} else {
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encodedStr = parts.join('');
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}
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}
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} else if (mimeWordEncoding === 'B') {
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encodedStr = libbase64.encode(data);
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}
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return '=?' + toCharset + '?' + mimeWordEncoding + '?' + encodedStr + (encodedStr.substr(-2) === '?=' ? '' : '?=');
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}
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/**
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* Decode a complete mime word encoded string
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*
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* @param {String} str Mime word encoded string
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* @return {String} Decoded unicode string
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*/
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decodeWord(charset, encoding, str) {
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// RFC2231 added language tag to the encoding
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// see: https://tools.ietf.org/html/rfc2231#section-5
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// this implementation silently ignores this tag
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let splitPos = charset.indexOf('*');
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if (splitPos >= 0) {
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charset = charset.substr(0, splitPos);
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}
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charset = libcharset.normalizeCharset(charset);
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encoding = encoding.toUpperCase();
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if (encoding === 'Q') {
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str = str
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// remove spaces between = and hex char, this might indicate invalidly applied line splitting
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.replace(/=\s+([0-9a-fA-F])/g, '=$1')
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// convert all underscores to spaces
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.replace(/[_\s]/g, ' ');
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let buf = Buffer.from(str);
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let bytes = [];
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for (let i = 0, len = buf.length; i < len; i++) {
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let c = buf[i];
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if (i <= len - 2 && c === 0x3d /* = */) {
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let c1 = this.getHex(buf[i + 1]);
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let c2 = this.getHex(buf[i + 2]);
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if (c1 && c2) {
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let c = parseInt(c1 + c2, 16);
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bytes.push(c);
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i += 2;
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continue;
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}
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}
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bytes.push(c);
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}
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str = Buffer.from(bytes);
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} else if (encoding === 'B') {
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str = Buffer.concat(
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str
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.split('=')
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.filter(s => s !== '') // filter empty string
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.map(str => Buffer.from(str, 'base64'))
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);
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} else {
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// keep as is, convert Buffer to unicode string, assume utf8
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str = Buffer.from(str);
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}
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return libcharset.decode(str, charset, this.config.Iconv);
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}
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/**
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* Finds word sequences with non ascii text and converts these to mime words
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*
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* @param {String|Buffer} data String to be encoded
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* @param {String} mimeWordEncoding='Q' Encoding for the mime word, either Q or B
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* @param {Number} [maxLength=0] If set, split mime words into several chunks if needed
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* @param {String} [fromCharset='UTF-8'] Source sharacter set
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* @return {String} String with possible mime words
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*/
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encodeWords(data, mimeWordEncoding, maxLength, fromCharset) {
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if (!fromCharset && typeof maxLength === 'string' && !maxLength.match(/^[0-9]+$/)) {
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fromCharset = maxLength;
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maxLength = undefined;
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}
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maxLength = maxLength || 0;
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let decodedValue = libcharset.decode(libcharset.convert(data || '', fromCharset, this.config.Iconv), this.config.Iconv);
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let encodedValue;
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let firstMatch = decodedValue.match(/(?:^|\s)([^\s]*[\u0080-\uFFFF])/);
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if (!firstMatch) {
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return decodedValue;
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}
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let lastMatch = decodedValue.match(/([\u0080-\uFFFF][^\s]*)[^\u0080-\uFFFF]*$/);
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if (!lastMatch) {
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// should not happen
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return decodedValue;
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}
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let startIndex =
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firstMatch.index +
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(
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firstMatch[0].match(/[^\s]/) || {
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index: 0
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}
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).index;
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let endIndex = lastMatch.index + (lastMatch[1] || '').length;
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encodedValue =
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(startIndex ? decodedValue.substr(0, startIndex) : '') +
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this.encodeWord(decodedValue.substring(startIndex, endIndex), mimeWordEncoding || 'Q', maxLength) +
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(endIndex < decodedValue.length ? decodedValue.substr(endIndex) : '');
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return encodedValue;
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}
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/**
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* Decode a string that might include one or several mime words
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*
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* @param {String} str String including some mime words that will be encoded
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* @return {String} Decoded unicode string
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*/
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decodeWords(str) {
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return (
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(str || '')
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.toString()
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// find base64 words that can be joined
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.replace(/(=\?([^?]+)\?[Bb]\?[^?]*\?=)\s*(?==\?([^?]+)\?[Bb]\?[^?]*\?=)/g, (match, left, chLeft, chRight) => {
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// only mark b64 chunks to be joined if charsets match
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if (libcharset.normalizeCharset(chLeft || '') === libcharset.normalizeCharset(chRight || '')) {
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// set a joiner marker
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return left + '__\x00JOIN\x00__';
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}
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return match;
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})
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// find QP words that can be joined
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.replace(/(=\?([^?]+)\?[Qq]\?[^?]*\?=)\s*(?==\?([^?]+)\?[Qq]\?[^?]*\?=)/g, (match, left, chLeft, chRight) => {
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// only mark QP chunks to be joined if charsets match
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if (libcharset.normalizeCharset(chLeft || '') === libcharset.normalizeCharset(chRight || '')) {
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// set a joiner marker
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return left + '__\x00JOIN\x00__';
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}
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return match;
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})
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||
// join base64 encoded words
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.replace(/(\?=)?__\x00JOIN\x00__(=\?([^?]+)\?[QqBb]\?)?/g, '')
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// remove spaces between mime encoded words
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||
.replace(/(=\?[^?]+\?[QqBb]\?[^?]*\?=)\s+(?==\?[^?]+\?[QqBb]\?[^?]*\?=)/g, '$1')
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// decode words
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.replace(/=\?([\w_\-*]+)\?([QqBb])\?([^?]*)\?=/g, (m, charset, encoding, text) => this.decodeWord(charset, encoding, text))
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);
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}
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||
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||
getHex(c) {
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if ((c >= 0x30 /* 0 */ && c <= 0x39) /* 9 */ || (c >= 0x61 /* a */ && c <= 0x66) /* f */ || (c >= 0x41 /* A */ && c <= 0x46) /* F */) {
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||
return String.fromCharCode(c);
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||
}
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return false;
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||
}
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||
|
||
/**
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||
* Splits a string by :
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* The result is not mime word decoded, you need to do your own decoding based
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* on the rules for the specific header key
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*
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* @param {String} headerLine Single header line, might include linebreaks as well if folded
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||
* @return {Object} And object of {key, value}
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||
*/
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decodeHeader(headerLine) {
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let line = (headerLine || '')
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.toString()
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.replace(/(?:\r?\n|\r)[ \t]*/g, ' ')
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.trim(),
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match = line.match(/^\s*([^:]+):(.*)$/),
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key = ((match && match[1]) || '').trim().toLowerCase(),
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value = ((match && match[2]) || '').trim();
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||
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||
return {
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key,
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||
value
|
||
};
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||
}
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||
|
||
/**
|
||
* Parses a block of header lines. Does not decode mime words as every
|
||
* header might have its own rules (eg. formatted email addresses and such)
|
||
*
|
||
* @param {String} headers Headers string
|
||
* @return {Object} An object of headers, where header keys are object keys. NB! Several values with the same key make up an Array
|
||
*/
|
||
decodeHeaders(headers) {
|
||
let lines = headers.split(/\r?\n|\r/),
|
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headersObj = {},
|
||
header,
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||
i,
|
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len;
|
||
|
||
for (i = lines.length - 1; i >= 0; i--) {
|
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if (i && lines[i].match(/^\s/)) {
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||
lines[i - 1] += '\r\n' + lines[i];
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||
lines.splice(i, 1);
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||
}
|
||
}
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||
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||
for (i = 0, len = lines.length; i < len; i++) {
|
||
header = this.decodeHeader(lines[i]);
|
||
if (!headersObj[header.key]) {
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||
headersObj[header.key] = [header.value];
|
||
} else {
|
||
headersObj[header.key].push(header.value);
|
||
}
|
||
}
|
||
|
||
return headersObj;
|
||
}
|
||
|
||
/**
|
||
* Joins parsed header value together as 'value; param1=value1; param2=value2'
|
||
* PS: We are following RFC 822 for the list of special characters that we need to keep in quotes.
|
||
* Refer: https://www.w3.org/Protocols/rfc1341/4_Content-Type.html
|
||
* @param {Object} structured Parsed header value
|
||
* @return {String} joined header value
|
||
*/
|
||
buildHeaderValue(structured) {
|
||
let paramsArray = [];
|
||
|
||
Object.keys(structured.params || {}).forEach(param => {
|
||
// filename might include unicode characters so it is a special case
|
||
let value = structured.params[param];
|
||
if (!this.isPlainText(value) || value.length >= 75) {
|
||
this.buildHeaderParam(param, value, 50).forEach(encodedParam => {
|
||
if (!/[\s"\\;:/=(),<>@[\]?]|^[-']|'$/.test(encodedParam.value) || encodedParam.key.substr(-1) === '*') {
|
||
paramsArray.push(encodedParam.key + '=' + encodedParam.value);
|
||
} else {
|
||
paramsArray.push(encodedParam.key + '=' + JSON.stringify(encodedParam.value));
|
||
}
|
||
});
|
||
} else if (/[\s'"\\;:/=(),<>@[\]?]|^-/.test(value)) {
|
||
paramsArray.push(param + '=' + JSON.stringify(value));
|
||
} else {
|
||
paramsArray.push(param + '=' + value);
|
||
}
|
||
});
|
||
|
||
return structured.value + (paramsArray.length ? '; ' + paramsArray.join('; ') : '');
|
||
}
|
||
|
||
/**
|
||
* Parses a header value with key=value arguments into a structured
|
||
* object.
|
||
*
|
||
* parseHeaderValue('content-type: text/plain; CHARSET='UTF-8'') ->
|
||
* {
|
||
* 'value': 'text/plain',
|
||
* 'params': {
|
||
* 'charset': 'UTF-8'
|
||
* }
|
||
* }
|
||
*
|
||
* @param {String} str Header value
|
||
* @return {Object} Header value as a parsed structure
|
||
*/
|
||
parseHeaderValue(str) {
|
||
let response = {
|
||
value: false,
|
||
params: {}
|
||
};
|
||
let key = false;
|
||
let value = '';
|
||
let stage = STAGE_VALUE;
|
||
|
||
let quote = false;
|
||
let escaped = false;
|
||
let chr;
|
||
|
||
for (let i = 0, len = str.length; i < len; i++) {
|
||
chr = str.charAt(i);
|
||
switch (stage) {
|
||
case STAGE_KEY:
|
||
if (chr === '=') {
|
||
key = value.trim().toLowerCase();
|
||
stage = STAGE_VALUE;
|
||
value = '';
|
||
break;
|
||
}
|
||
value += chr;
|
||
break;
|
||
case STAGE_VALUE:
|
||
if (escaped) {
|
||
value += chr;
|
||
} else if (chr === '\\') {
|
||
escaped = true;
|
||
continue;
|
||
} else if (quote && chr === quote) {
|
||
quote = false;
|
||
} else if (!quote && chr === '"') {
|
||
quote = chr;
|
||
} else if (!quote && chr === ';') {
|
||
if (key === false) {
|
||
response.value = value.trim();
|
||
} else {
|
||
response.params[key] = value.trim();
|
||
}
|
||
stage = STAGE_KEY;
|
||
value = '';
|
||
} else {
|
||
value += chr;
|
||
}
|
||
escaped = false;
|
||
break;
|
||
}
|
||
}
|
||
|
||
// finalize remainder
|
||
value = value.trim();
|
||
if (stage === STAGE_VALUE) {
|
||
if (key === false) {
|
||
// default value
|
||
response.value = value;
|
||
} else {
|
||
// subkey value
|
||
response.params[key] = value;
|
||
}
|
||
} else if (value) {
|
||
// treat as key without value, see emptykey:
|
||
// Header-Key: somevalue; key=value; emptykey
|
||
response.params[value.toLowerCase()] = '';
|
||
}
|
||
|
||
// handle parameter value continuations
|
||
// https://tools.ietf.org/html/rfc2231#section-3
|
||
|
||
// preprocess values
|
||
Object.keys(response.params).forEach(key => {
|
||
let actualKey;
|
||
let nr;
|
||
let value;
|
||
|
||
let match = key.match(/\*((\d+)\*?)?$/);
|
||
|
||
if (!match) {
|
||
// nothing to do here, does not seem like a continuation param
|
||
return;
|
||
}
|
||
|
||
actualKey = key.substr(0, match.index).toLowerCase();
|
||
nr = Number(match[2]) || 0;
|
||
|
||
if (!response.params[actualKey] || typeof response.params[actualKey] !== 'object') {
|
||
response.params[actualKey] = {
|
||
charset: false,
|
||
values: []
|
||
};
|
||
}
|
||
|
||
value = response.params[key];
|
||
|
||
if (nr === 0 && match[0].charAt(match[0].length - 1) === '*' && (match = value.match(/^([^']*)'[^']*'(.*)$/))) {
|
||
response.params[actualKey].charset = match[1] || 'utf-8';
|
||
value = match[2];
|
||
}
|
||
|
||
response.params[actualKey].values.push({ nr, value });
|
||
|
||
// remove the old reference
|
||
delete response.params[key];
|
||
});
|
||
|
||
// concatenate split rfc2231 strings and convert encoded strings to mime encoded words
|
||
Object.keys(response.params).forEach(key => {
|
||
let value;
|
||
if (response.params[key] && Array.isArray(response.params[key].values)) {
|
||
value = response.params[key].values
|
||
.sort((a, b) => a.nr - b.nr)
|
||
.map(val => (val && val.value) || '')
|
||
.join('');
|
||
|
||
if (response.params[key].charset) {
|
||
// convert "%AB" to "=?charset?Q?=AB?=" and then to unicode
|
||
response.params[key] = this.decodeWords(
|
||
'=?' +
|
||
response.params[key].charset +
|
||
'?Q?' +
|
||
value
|
||
// fix invalidly encoded chars
|
||
.replace(/[=?_\s]/g, s => {
|
||
let c = s.charCodeAt(0).toString(16);
|
||
if (s === ' ') {
|
||
return '_';
|
||
} else {
|
||
return '%' + (c.length < 2 ? '0' : '') + c;
|
||
}
|
||
})
|
||
// change from urlencoding to percent encoding
|
||
.replace(/%/g, '=') +
|
||
'?='
|
||
);
|
||
} else {
|
||
response.params[key] = this.decodeWords(value);
|
||
}
|
||
}
|
||
});
|
||
|
||
return response;
|
||
}
|
||
|
||
/**
|
||
* Encodes a string or an Buffer to an UTF-8 Parameter Value Continuation encoding (rfc2231)
|
||
* Useful for splitting long parameter values.
|
||
*
|
||
* For example
|
||
* title="unicode string"
|
||
* becomes
|
||
* title*0*=utf-8''unicode
|
||
* title*1*=%20string
|
||
*
|
||
* @param {String|Buffer} data String to be encoded
|
||
* @param {Number} [maxLength=50] Max length for generated chunks
|
||
* @param {String} [fromCharset='UTF-8'] Source sharacter set
|
||
* @return {Array} A list of encoded keys and headers
|
||
*/
|
||
buildHeaderParam(key, data, maxLength, fromCharset) {
|
||
let list = [];
|
||
let encodedStr = typeof data === 'string' ? data : this.decode(data, fromCharset);
|
||
let encodedStrArr;
|
||
let chr, ord;
|
||
let line;
|
||
let startPos = 0;
|
||
let isEncoded = false;
|
||
let i, len;
|
||
|
||
maxLength = maxLength || 50;
|
||
|
||
// process ascii only text
|
||
if (this.isPlainText(data)) {
|
||
// check if conversion is even needed
|
||
if (encodedStr.length <= maxLength) {
|
||
return [
|
||
{
|
||
key,
|
||
value: encodedStr
|
||
}
|
||
];
|
||
}
|
||
|
||
encodedStr = encodedStr.replace(new RegExp('.{' + maxLength + '}', 'g'), str => {
|
||
list.push({
|
||
line: str
|
||
});
|
||
return '';
|
||
});
|
||
|
||
if (encodedStr) {
|
||
list.push({
|
||
line: encodedStr
|
||
});
|
||
}
|
||
} else {
|
||
if (/[\uD800-\uDBFF]/.test(encodedStr)) {
|
||
// string containts surrogate pairs, so normalize it to an array of bytes
|
||
encodedStrArr = [];
|
||
for (i = 0, len = encodedStr.length; i < len; i++) {
|
||
chr = encodedStr.charAt(i);
|
||
ord = chr.charCodeAt(0);
|
||
if (ord >= 0xd800 && ord <= 0xdbff && i < len - 1) {
|
||
chr += encodedStr.charAt(i + 1);
|
||
encodedStrArr.push(chr);
|
||
i++;
|
||
} else {
|
||
encodedStrArr.push(chr);
|
||
}
|
||
}
|
||
encodedStr = encodedStrArr;
|
||
}
|
||
|
||
// first line includes the charset and language info and needs to be encoded
|
||
// even if it does not contain any unicode characters
|
||
line = "utf-8''";
|
||
isEncoded = true;
|
||
startPos = 0;
|
||
|
||
// process text with unicode or special chars
|
||
for (i = 0, len = encodedStr.length; i < len; i++) {
|
||
chr = encodedStr[i];
|
||
|
||
if (isEncoded) {
|
||
chr = this.safeEncodeURIComponent(chr);
|
||
} else {
|
||
// try to urlencode current char
|
||
chr = chr === ' ' ? chr : this.safeEncodeURIComponent(chr);
|
||
// By default it is not required to encode a line, the need
|
||
// only appears when the string contains unicode or special chars
|
||
// in this case we start processing the line over and encode all chars
|
||
if (chr !== encodedStr[i]) {
|
||
// Check if it is even possible to add the encoded char to the line
|
||
// If not, there is no reason to use this line, just push it to the list
|
||
// and start a new line with the char that needs encoding
|
||
if ((this.safeEncodeURIComponent(line) + chr).length >= maxLength) {
|
||
list.push({
|
||
line,
|
||
encoded: isEncoded
|
||
});
|
||
line = '';
|
||
startPos = i - 1;
|
||
} else {
|
||
isEncoded = true;
|
||
i = startPos;
|
||
line = '';
|
||
continue;
|
||
}
|
||
}
|
||
}
|
||
|
||
// if the line is already too long, push it to the list and start a new one
|
||
if ((line + chr).length >= maxLength) {
|
||
list.push({
|
||
line,
|
||
encoded: isEncoded
|
||
});
|
||
line = chr = encodedStr[i] === ' ' ? ' ' : this.safeEncodeURIComponent(encodedStr[i]);
|
||
if (chr === encodedStr[i]) {
|
||
isEncoded = false;
|
||
startPos = i - 1;
|
||
} else {
|
||
isEncoded = true;
|
||
}
|
||
} else {
|
||
line += chr;
|
||
}
|
||
}
|
||
|
||
if (line) {
|
||
list.push({
|
||
line,
|
||
encoded: isEncoded
|
||
});
|
||
}
|
||
}
|
||
|
||
return list.map((item, i) => ({
|
||
// encoded lines: {name}*{part}*
|
||
// unencoded lines: {name}*{part}
|
||
// if any line needs to be encoded then the first line (part==0) is always encoded
|
||
key: key + '*' + i + (item.encoded ? '*' : ''),
|
||
value: item.line
|
||
}));
|
||
}
|
||
|
||
/**
|
||
* Returns file extension for a content type string. If no suitable extensions
|
||
* are found, 'bin' is used as the default extension
|
||
*
|
||
* @param {String} mimeType Content type to be checked for
|
||
* @return {String} File extension
|
||
*/
|
||
detectExtension(mimeType) {
|
||
mimeType = (mimeType || '')
|
||
.toString()
|
||
.toLowerCase()
|
||
.replace(/\s/g, '');
|
||
if (!(mimeType in mimetypes.list)) {
|
||
return 'bin';
|
||
}
|
||
|
||
if (typeof mimetypes.list[mimeType] === 'string') {
|
||
return mimetypes.list[mimeType];
|
||
}
|
||
|
||
let mimeParts = mimeType.split('/');
|
||
|
||
// search for name match
|
||
for (let i = 0, len = mimetypes.list[mimeType].length; i < len; i++) {
|
||
if (mimeParts[1] === mimetypes.list[mimeType][i]) {
|
||
return mimetypes.list[mimeType][i];
|
||
}
|
||
}
|
||
|
||
// use the first one
|
||
return mimetypes.list[mimeType][0] !== '*' ? mimetypes.list[mimeType][0] : 'bin';
|
||
}
|
||
|
||
/**
|
||
* Returns content type for a file extension. If no suitable content types
|
||
* are found, 'application/octet-stream' is used as the default content type
|
||
*
|
||
* @param {String} extension Extension to be checked for
|
||
* @return {String} File extension
|
||
*/
|
||
detectMimeType(extension) {
|
||
extension = (extension || '')
|
||
.toString()
|
||
.toLowerCase()
|
||
.replace(/\s/g, '')
|
||
.replace(/^\./g, '')
|
||
.split('.')
|
||
.pop();
|
||
|
||
if (!(extension in mimetypes.extensions)) {
|
||
return 'application/octet-stream';
|
||
}
|
||
|
||
if (typeof mimetypes.extensions[extension] === 'string') {
|
||
return mimetypes.extensions[extension];
|
||
}
|
||
|
||
let mimeParts;
|
||
|
||
// search for name match
|
||
for (let i = 0, len = mimetypes.extensions[extension].length; i < len; i++) {
|
||
mimeParts = mimetypes.extensions[extension][i].split('/');
|
||
if (mimeParts[1] === extension) {
|
||
return mimetypes.extensions[extension][i];
|
||
}
|
||
}
|
||
|
||
// use the first one
|
||
return mimetypes.extensions[extension][0];
|
||
}
|
||
|
||
/**
|
||
* Folds long lines, useful for folding header lines (afterSpace=false) and
|
||
* flowed text (afterSpace=true)
|
||
*
|
||
* @param {String} str String to be folded
|
||
* @param {Number} [lineLength=76] Maximum length of a line
|
||
* @param {Boolean} afterSpace If true, leave a space in th end of a line
|
||
* @return {String} String with folded lines
|
||
*/
|
||
foldLines(str, lineLength, afterSpace) {
|
||
str = (str || '').toString();
|
||
lineLength = lineLength || 76;
|
||
|
||
let pos = 0,
|
||
len = str.length,
|
||
result = '',
|
||
line,
|
||
match;
|
||
|
||
while (pos < len) {
|
||
line = str.substr(pos, lineLength);
|
||
if (line.length < lineLength) {
|
||
result += line;
|
||
break;
|
||
}
|
||
if ((match = line.match(/^[^\n\r]*(\r?\n|\r)/))) {
|
||
line = match[0];
|
||
result += line;
|
||
pos += line.length;
|
||
continue;
|
||
} else if ((match = line.match(/(\s+)[^\s]*$/)) && match[0].length - (afterSpace ? (match[1] || '').length : 0) < line.length) {
|
||
line = line.substr(0, line.length - (match[0].length - (afterSpace ? (match[1] || '').length : 0)));
|
||
} else if ((match = str.substr(pos + line.length).match(/^[^\s]+(\s*)/))) {
|
||
line = line + match[0].substr(0, match[0].length - (!afterSpace ? (match[1] || '').length : 0));
|
||
}
|
||
|
||
result += line;
|
||
pos += line.length;
|
||
if (pos < len) {
|
||
result += '\r\n';
|
||
}
|
||
}
|
||
|
||
return result;
|
||
}
|
||
|
||
/**
|
||
* Splits a mime encoded string. Needed for dividing mime words into smaller chunks
|
||
*
|
||
* @param {String} str Mime encoded string to be split up
|
||
* @param {Number} maxlen Maximum length of characters for one part (minimum 12)
|
||
* @return {Array} Split string
|
||
*/
|
||
splitMimeEncodedString(str, maxlen) {
|
||
let curLine,
|
||
match,
|
||
chr,
|
||
done,
|
||
lines = [];
|
||
|
||
// require at least 12 symbols to fit possible 4 octet UTF-8 sequences
|
||
maxlen = Math.max(maxlen || 0, 12);
|
||
|
||
while (str.length) {
|
||
curLine = str.substr(0, maxlen);
|
||
|
||
// move incomplete escaped char back to main
|
||
if ((match = curLine.match(/[=][0-9A-F]?$/i))) {
|
||
curLine = curLine.substr(0, match.index);
|
||
}
|
||
|
||
done = false;
|
||
while (!done) {
|
||
done = true;
|
||
// check if not middle of a unicode char sequence
|
||
if ((match = str.substr(curLine.length).match(/^[=]([0-9A-F]{2})/i))) {
|
||
chr = parseInt(match[1], 16);
|
||
// invalid sequence, move one char back anc recheck
|
||
if (chr < 0xc2 && chr > 0x7f) {
|
||
curLine = curLine.substr(0, curLine.length - 3);
|
||
done = false;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (curLine.length) {
|
||
lines.push(curLine);
|
||
}
|
||
str = str.substr(curLine.length);
|
||
}
|
||
|
||
return lines;
|
||
}
|
||
|
||
encodeURICharComponent(chr) {
|
||
let res = '';
|
||
let ord = chr
|
||
.charCodeAt(0)
|
||
.toString(16)
|
||
.toUpperCase();
|
||
|
||
if (ord.length % 2) {
|
||
ord = '0' + ord;
|
||
}
|
||
|
||
if (ord.length > 2) {
|
||
for (let i = 0, len = ord.length / 2; i < len; i++) {
|
||
res += '%' + ord.substr(i, 2);
|
||
}
|
||
} else {
|
||
res += '%' + ord;
|
||
}
|
||
|
||
return res;
|
||
}
|
||
|
||
safeEncodeURIComponent(str) {
|
||
str = (str || '').toString();
|
||
|
||
try {
|
||
// might throw if we try to encode invalid sequences, eg. partial emoji
|
||
str = encodeURIComponent(str);
|
||
} catch (E) {
|
||
// should never run
|
||
return str.replace(/[^\x00-\x1F *'()<>@,;:\\"[\]?=\u007F-\uFFFF]+/g, '');
|
||
}
|
||
|
||
// ensure chars that are not handled by encodeURICompent are converted as well
|
||
return str.replace(/[\x00-\x1F *'()<>@,;:\\"[\]?=\u007F-\uFFFF]/g, chr => this.encodeURICharComponent(chr));
|
||
}
|
||
}
|
||
|
||
module.exports = new Libmime();
|
||
module.exports.Libmime = Libmime;
|