423 lines
15 KiB
JavaScript
423 lines
15 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
const Transform = require('stream').Transform;
|
||
|
|
const MimeNode = require('./mime-node');
|
||
|
|
|
||
|
|
const MAX_HEAD_SIZE = 1 * 1024 * 1024;
|
||
|
|
const MAX_CHILD_NODES = 1000;
|
||
|
|
|
||
|
|
const HEAD = 0x01;
|
||
|
|
const BODY = 0x02;
|
||
|
|
|
||
|
|
class MessageSplitter extends Transform {
|
||
|
|
constructor(config) {
|
||
|
|
let options = {
|
||
|
|
readableObjectMode: true,
|
||
|
|
writableObjectMode: false
|
||
|
|
};
|
||
|
|
super(options);
|
||
|
|
|
||
|
|
this.config = config || {};
|
||
|
|
this.maxHeadSize = this.config.maxHeadSize || MAX_HEAD_SIZE;
|
||
|
|
this.maxChildNodes = this.config.maxChildNodes || MAX_CHILD_NODES;
|
||
|
|
this.tree = [];
|
||
|
|
this.nodeCounter = 0;
|
||
|
|
this.newNode();
|
||
|
|
this.tree.push(this.node);
|
||
|
|
this.line = false;
|
||
|
|
this.errored = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
_transform(chunk, encoding, callback) {
|
||
|
|
// process line by line
|
||
|
|
// find next line ending
|
||
|
|
let pos = 0;
|
||
|
|
let i = 0;
|
||
|
|
let group = {
|
||
|
|
type: 'none'
|
||
|
|
};
|
||
|
|
let groupstart = this.line ? -this.line.length : 0;
|
||
|
|
let groupend = 0;
|
||
|
|
|
||
|
|
let checkTrailingLinebreak = data => {
|
||
|
|
if (data.type === 'body' && data.node.parentNode && data.value && data.value.length) {
|
||
|
|
if (data.value[data.value.length - 1] === 0x0a) {
|
||
|
|
groupstart--;
|
||
|
|
groupend--;
|
||
|
|
pos--;
|
||
|
|
if (data.value.length > 1 && data.value[data.value.length - 2] === 0x0d) {
|
||
|
|
groupstart--;
|
||
|
|
groupend--;
|
||
|
|
pos--;
|
||
|
|
if (groupstart < 0 && !this.line) {
|
||
|
|
// store only <CR> as <LF> should be on the positive side
|
||
|
|
this.line = Buffer.allocUnsafe(1);
|
||
|
|
this.line[0] = 0x0d;
|
||
|
|
}
|
||
|
|
data.value = data.value.slice(0, data.value.length - 2);
|
||
|
|
} else {
|
||
|
|
data.value = data.value.slice(0, data.value.length - 1);
|
||
|
|
}
|
||
|
|
} else if (data.value[data.value.length - 1] === 0x0d) {
|
||
|
|
groupstart--;
|
||
|
|
groupend--;
|
||
|
|
pos--;
|
||
|
|
data.value = data.value.slice(0, data.value.length - 1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
let iterateData = () => {
|
||
|
|
for (let len = chunk.length; i < len; i++) {
|
||
|
|
// find next <LF>
|
||
|
|
if (chunk[i] === 0x0a) {
|
||
|
|
// line end
|
||
|
|
|
||
|
|
let start = Math.max(pos, 0);
|
||
|
|
pos = ++i;
|
||
|
|
|
||
|
|
return this.processLine(chunk.slice(start, i), false, (err, data, flush) => {
|
||
|
|
if (err) {
|
||
|
|
this.errored = true;
|
||
|
|
return setImmediate(() => callback(err));
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!data) {
|
||
|
|
return setImmediate(iterateData);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (flush) {
|
||
|
|
if (group && group.type !== 'none') {
|
||
|
|
if (group.type === 'body' && groupend >= groupstart && group.node.parentNode) {
|
||
|
|
// do not include the last line ending for body
|
||
|
|
if (chunk[groupend - 1] === 0x0a) {
|
||
|
|
groupend--;
|
||
|
|
if (groupend >= groupstart && chunk[groupend - 1] === 0x0d) {
|
||
|
|
groupend--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (groupstart !== groupend) {
|
||
|
|
group.value = chunk.slice(groupstart, groupend);
|
||
|
|
if (groupend < i) {
|
||
|
|
data.value = chunk.slice(groupend, i);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
this.push(group);
|
||
|
|
group = {
|
||
|
|
type: 'none'
|
||
|
|
};
|
||
|
|
groupstart = groupend = i;
|
||
|
|
}
|
||
|
|
this.push(data);
|
||
|
|
groupend = i;
|
||
|
|
return setImmediate(iterateData);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (data.type === group.type) {
|
||
|
|
// shift slice end position forward
|
||
|
|
groupend = i;
|
||
|
|
} else {
|
||
|
|
if (group.type === 'body' && groupend >= groupstart && group.node.parentNode) {
|
||
|
|
// do not include the last line ending for body
|
||
|
|
if (chunk[groupend - 1] === 0x0a) {
|
||
|
|
groupend--;
|
||
|
|
if (groupend >= groupstart && chunk[groupend - 1] === 0x0d) {
|
||
|
|
groupend--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (group.type !== 'none' && group.type !== 'node') {
|
||
|
|
// we have a previous data/body chunk to output
|
||
|
|
if (groupstart !== groupend) {
|
||
|
|
group.value = chunk.slice(groupstart, groupend);
|
||
|
|
if (group.value && group.value.length) {
|
||
|
|
this.push(group);
|
||
|
|
group = {
|
||
|
|
type: 'none'
|
||
|
|
};
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (data.type === 'node') {
|
||
|
|
this.push(data);
|
||
|
|
groupstart = i;
|
||
|
|
groupend = i;
|
||
|
|
} else if (groupstart < 0) {
|
||
|
|
groupstart = i;
|
||
|
|
groupend = i;
|
||
|
|
checkTrailingLinebreak(data);
|
||
|
|
if (data.value && data.value.length) {
|
||
|
|
this.push(data);
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
// start new body/data chunk
|
||
|
|
group = data;
|
||
|
|
groupstart = groupend;
|
||
|
|
groupend = i;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return setImmediate(iterateData);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// skip last linebreak for body
|
||
|
|
if (pos >= groupstart + 1 && group.type === 'body' && group.node.parentNode) {
|
||
|
|
// do not include the last line ending for body
|
||
|
|
if (chunk[pos - 1] === 0x0a) {
|
||
|
|
pos--;
|
||
|
|
if (pos >= groupstart && chunk[pos - 1] === 0x0d) {
|
||
|
|
pos--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (group.type !== 'none' && group.type !== 'node' && pos > groupstart) {
|
||
|
|
// we have a leftover data/body chunk to push out
|
||
|
|
group.value = chunk.slice(groupstart, pos);
|
||
|
|
|
||
|
|
if (group.value && group.value.length) {
|
||
|
|
this.push(group);
|
||
|
|
group = {
|
||
|
|
type: 'none'
|
||
|
|
};
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (pos < chunk.length) {
|
||
|
|
if (this.line) {
|
||
|
|
this.line = Buffer.concat([this.line, chunk.slice(pos)]);
|
||
|
|
} else {
|
||
|
|
this.line = chunk.slice(pos);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
callback();
|
||
|
|
};
|
||
|
|
|
||
|
|
setImmediate(iterateData);
|
||
|
|
}
|
||
|
|
|
||
|
|
_flush(callback) {
|
||
|
|
if (this.errored) {
|
||
|
|
return callback();
|
||
|
|
}
|
||
|
|
this.processLine(false, true, (err, data) => {
|
||
|
|
if (err) {
|
||
|
|
return setImmediate(() => callback(err));
|
||
|
|
}
|
||
|
|
if (data && (data.type === 'node' || (data.value && data.value.length))) {
|
||
|
|
this.push(data);
|
||
|
|
}
|
||
|
|
callback();
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
compareBoundary(line, startpos, boundary) {
|
||
|
|
// --{boundary}\r\n or --{boundary}--\r\n
|
||
|
|
if (line.length < boundary.length + 3 + startpos || line.length > boundary.length + 6 + startpos) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
for (let i = 0; i < boundary.length; i++) {
|
||
|
|
if (line[i + 2 + startpos] !== boundary[i]) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
let pos = 0;
|
||
|
|
for (let i = boundary.length + 2 + startpos; i < line.length; i++) {
|
||
|
|
let c = line[i];
|
||
|
|
if (pos === 0 && (c === 0x0d || c === 0x0a)) {
|
||
|
|
// 1: next node
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
if (pos === 0 && c !== 0x2d) {
|
||
|
|
// expecting "-"
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (pos === 1 && c !== 0x2d) {
|
||
|
|
// expecting "-"
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (pos === 2 && c !== 0x0d && c !== 0x0a) {
|
||
|
|
// expecting line terminator, either <CR> or <LF>
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (pos === 3 && c !== 0x0a) {
|
||
|
|
// expecting line terminator <LF>
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
pos++;
|
||
|
|
}
|
||
|
|
|
||
|
|
// 2: multipart end
|
||
|
|
return 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
checkBoundary(line) {
|
||
|
|
let startpos = 0;
|
||
|
|
if (line.length >= 1 && (line[0] === 0x0d || line[0] === 0x0a)) {
|
||
|
|
startpos++;
|
||
|
|
if (line.length >= 2 && (line[0] === 0x0d || line[1] === 0x0a)) {
|
||
|
|
startpos++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (line.length < 4 || line[startpos] !== 0x2d || line[startpos + 1] !== 0x2d) {
|
||
|
|
// defnitely not a boundary
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
let boundary;
|
||
|
|
if (this.node._boundary && (boundary = this.compareBoundary(line, startpos, this.node._boundary))) {
|
||
|
|
// 1: next child
|
||
|
|
// 2: multipart end
|
||
|
|
return boundary;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (this.node._parentBoundary && (boundary = this.compareBoundary(line, startpos, this.node._parentBoundary))) {
|
||
|
|
// 3: next sibling
|
||
|
|
// 4: parent end
|
||
|
|
return boundary + 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
processLine(line, final, next) {
|
||
|
|
let flush = false;
|
||
|
|
|
||
|
|
if (this.line && line) {
|
||
|
|
line = Buffer.concat([this.line, line]);
|
||
|
|
this.line = false;
|
||
|
|
} else if (this.line && !line) {
|
||
|
|
line = this.line;
|
||
|
|
this.line = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!line) {
|
||
|
|
line = Buffer.alloc(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (this.nodeCounter > this.maxChildNodes) {
|
||
|
|
let err = new Error('Max allowed child nodes exceeded');
|
||
|
|
err.code = 'EMAXLEN';
|
||
|
|
return next(err);
|
||
|
|
}
|
||
|
|
|
||
|
|
// we check boundary outside the HEAD/BODY scope as it may appear anywhere
|
||
|
|
let boundary = this.checkBoundary(line);
|
||
|
|
if (boundary) {
|
||
|
|
// reached boundary, switch context
|
||
|
|
switch (boundary) {
|
||
|
|
case 1:
|
||
|
|
// next child
|
||
|
|
this.newNode(this.node);
|
||
|
|
flush = true;
|
||
|
|
break;
|
||
|
|
case 2:
|
||
|
|
// reached end of children, keep current node
|
||
|
|
break;
|
||
|
|
case 3: {
|
||
|
|
// next sibling
|
||
|
|
let parentNode = this.node.parentNode;
|
||
|
|
if (parentNode && parentNode.contentType === 'message/rfc822') {
|
||
|
|
// special case where immediate parent is an inline message block
|
||
|
|
// move up another step
|
||
|
|
parentNode = parentNode.parentNode;
|
||
|
|
}
|
||
|
|
this.newNode(parentNode);
|
||
|
|
flush = true;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
case 4:
|
||
|
|
// special case when boundary close a node with only header.
|
||
|
|
if (this.node && this.node._headerlen && !this.node.headers) {
|
||
|
|
this.node.parseHeaders();
|
||
|
|
this.push(this.node);
|
||
|
|
}
|
||
|
|
// move up
|
||
|
|
if (this.tree.length) {
|
||
|
|
this.node = this.tree.pop();
|
||
|
|
}
|
||
|
|
this.state = BODY;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return next(
|
||
|
|
null,
|
||
|
|
{
|
||
|
|
node: this.node,
|
||
|
|
type: 'data',
|
||
|
|
value: line
|
||
|
|
},
|
||
|
|
flush
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
switch (this.state) {
|
||
|
|
case HEAD: {
|
||
|
|
this.node.addHeaderChunk(line);
|
||
|
|
if (this.node._headerlen > this.maxHeadSize) {
|
||
|
|
let err = new Error('Max header size for a MIME node exceeded');
|
||
|
|
err.code = 'EMAXLEN';
|
||
|
|
return next(err);
|
||
|
|
}
|
||
|
|
if (final || (line.length === 1 && line[0] === 0x0a) || (line.length === 2 && line[0] === 0x0d && line[1] === 0x0a)) {
|
||
|
|
let currentNode = this.node;
|
||
|
|
|
||
|
|
currentNode.parseHeaders();
|
||
|
|
|
||
|
|
// if the content is attached message then just continue
|
||
|
|
if (
|
||
|
|
currentNode.contentType === 'message/rfc822' &&
|
||
|
|
!this.config.ignoreEmbedded &&
|
||
|
|
(!currentNode.encoding || ['7bit', '8bit', 'binary'].includes(currentNode.encoding)) &&
|
||
|
|
currentNode.disposition !== 'attachment'
|
||
|
|
) {
|
||
|
|
currentNode.messageNode = true;
|
||
|
|
this.newNode(currentNode);
|
||
|
|
if (currentNode.parentNode) {
|
||
|
|
this.node._parentBoundary = currentNode.parentNode._boundary;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
if (currentNode.contentType === 'message/rfc822') {
|
||
|
|
currentNode.messageNode = false;
|
||
|
|
}
|
||
|
|
this.state = BODY;
|
||
|
|
if (currentNode.multipart && currentNode._boundary) {
|
||
|
|
this.tree.push(currentNode);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return next(null, currentNode, flush);
|
||
|
|
}
|
||
|
|
|
||
|
|
return next();
|
||
|
|
}
|
||
|
|
case BODY: {
|
||
|
|
return next(
|
||
|
|
null,
|
||
|
|
{
|
||
|
|
node: this.node,
|
||
|
|
type: this.node.multipart ? 'data' : 'body',
|
||
|
|
value: line
|
||
|
|
},
|
||
|
|
flush
|
||
|
|
);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
next(null, false);
|
||
|
|
}
|
||
|
|
|
||
|
|
newNode(parent) {
|
||
|
|
this.node = new MimeNode(parent || false, this.config);
|
||
|
|
this.state = HEAD;
|
||
|
|
this.nodeCounter++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = MessageSplitter;
|