'use strict';
const { Writable } = require('stream');
const { getDecoder } = require('../utils.js');
class URLEncoded extends Writable {
constructor(cfg) {
const streamOpts = {
autoDestroy: true,
emitClose: true,
highWaterMark: (typeof cfg.highWaterMark === 'number'
? cfg.highWaterMark
: undefined),
};
super(streamOpts);
let charset = (cfg.defCharset || 'utf8');
if (cfg.conType.params && typeof cfg.conType.params.charset === 'string')
charset = cfg.conType.params.charset;
this.charset = charset;
const limits = cfg.limits;
this.fieldSizeLimit = (limits && typeof limits.fieldSize === 'number'
? limits.fieldSize
: 1 * 1024 * 1024);
this.fieldsLimit = (limits && typeof limits.fields === 'number'
? limits.fields
: Infinity);
this.fieldNameSizeLimit = (
limits && typeof limits.fieldNameSize === 'number'
? limits.fieldNameSize
: 100
);
this._inKey = true;
this._keyTrunc = false;
this._valTrunc = false;
this._bytesKey = 0;
this._bytesVal = 0;
this._fields = 0;
this._key = '';
this._val = '';
this._byte = -2;
this._lastPos = 0;
this._encode = 0;
this._decoder = getDecoder(charset);
}
static detect(conType) {
return (conType.type === 'application'
&& conType.subtype === 'x-www-form-urlencoded');
}
_write(chunk, enc, cb) {
if (this._fields >= this.fieldsLimit)
return cb();
let i = 0;
const len = chunk.length;
this._lastPos = 0;
// Check if we last ended mid-percent-encoded byte
if (this._byte !== -2) {
i = readPctEnc(this, chunk, i, len);
if (i === -1)
return cb(new Error('Malformed urlencoded form'));
if (i >= len)
return cb();
if (this._inKey)
++this._bytesKey;
else
++this._bytesVal;
}
main:
while (i < len) {
if (this._inKey) {
// Parsing key
i = skipKeyBytes(this, chunk, i, len);
while (i < len) {
switch (chunk[i]) {
case 61: // '='
if (this._lastPos < i)
this._key += chunk.latin1Slice(this._lastPos, i);
this._lastPos = ++i;
this._key = this._decoder(this._key, this._encode);
this._encode = 0;
this._inKey = false;
continue main;
case 38: // '&'
if (this._lastPos < i)
this._key += chunk.latin1Slice(this._lastPos, i);
this._lastPos = ++i;
this._key = this._decoder(this._key, this._encode);
this._encode = 0;
if (this._bytesKey > 0) {
this.emit(
'field',
this._key,
'',
{ nameTruncated: this._keyTrunc,
valueTruncated: false,
encoding: this.charset,
mimeType: 'text/plain' }
);
}
this._key = '';
this._val = '';
this._keyTrunc = false;
this._valTrunc = false;
this._bytesKey = 0;
this._bytesVal = 0;
if (++this._fields >= this.fieldsLimit) {
this.emit('fieldsLimit');
return cb();
}
continue;
case 43: // '+'
if (this._lastPos < i)
this._key += chunk.latin1Slice(this._lastPos, i);
this._key += ' ';
this._lastPos = i + 1;
break;
case 37: // '%'
if (this._encode === 0)
this._encode = 1;
if (this._lastPos < i)
this._key += chunk.latin1Slice(this._lastPos, i);
this._lastPos = i + 1;
this._byte = -1;
i = readPctEnc(this, chunk, i + 1, len);
if (i === -1)
return cb(new Error('Malformed urlencoded form'));
if (i >= len)
return cb();
++this._bytesKey;
i = skipKeyBytes(this, chunk, i, len);
continue;
}
++i;
++this._bytesKey;
i = skipKeyBytes(this, chunk, i, len);
}
if (this._lastPos < i)
this._key += chunk.latin1Slice(this._lastPos, i);
} else {
// Parsing value
i = skipValBytes(this, chunk, i, len);
while (i < len) {
switch (chunk[i]) {
case 38: // '&'
if (this._lastPos < i)
this._val += chunk.latin1Slice(this._lastPos, i);
this._lastPos = ++i;
this._inKey = true;
this._val = this._decoder(this._val, this._encode);
this._encode = 0;
if (this._bytesKey > 0 || this._bytesVal > 0) {
this.emit(
'field',
this._key,
this._val,
{ nameTruncated: this._keyTrunc,
valueTruncated: this._valTrunc,
encoding: this.charset,
mimeType: 'text/plain' }
);
}
this._key = '';
this._val = '';
this._keyTrunc = false;
this._valTrunc = false;
this._bytesKey = 0;
this._bytesVal = 0;
if (++this._fields >= this.fieldsLimit) {
this.emit('fieldsLimit');
return cb();
}
continue main;
case 43: // '+'
if (this._lastPos < i)
this._val += chunk.latin1Slice(this._lastPos, i);
this._val += ' ';
this._lastPos = i + 1;
break;
case 37: // '%'
if (this._encode === 0)
this._encode = 1;
if (this._lastPos < i)
this._val += chunk.latin1Slice(this._lastPos, i);
this._lastPos = i + 1;
this._byte = -1;
i = readPctEnc(this, chunk, i + 1, len);
if (i === -1)
return cb(new Error('Malformed urlencoded form'));
if (i >= len)
return cb();
++this._bytesVal;
i = skipValBytes(this, chunk, i, len);
continue;
}
++i;
++this._bytesVal;
i = skipValBytes(this, chunk, i, len);
}
if (this._lastPos < i)
this._val += chunk.latin1Slice(this._lastPos, i);
}
}
cb();
}
_final(cb) {
if (this._byte !== -2)
return cb(new Error('Malformed urlencoded form'));
if (!this._inKey || this._bytesKey > 0 || this._bytesVal > 0) {
if (this._inKey)
this._key = this._decoder(this._key, this._encode);
else
this._val = this._decoder(this._val, this._encode);
this.emit(
'field',
this._key,
this._val,
{ nameTruncated: this._keyTrunc,
valueTruncated: this._valTrunc,
encoding: this.charset,
mimeType: 'text/plain' }
);
}
cb();
}
}
function readPctEnc(self, chunk, pos, len) {
if (pos >= len)
return len;
if (self._byte === -1) {
// We saw a '%' but no hex characters yet
const hexUpper = HEX_VALUES[chunk[pos++]];
if (hexUpper === -1)
return -1;
if (hexUpper >= 8)
self._encode = 2; // Indicate high bits detected
if (pos < len) {
// Both hex characters are in this chunk
const hexLower = HEX_VALUES[chunk[pos++]];
if (hexLower === -1)
return -1;
if (self._inKey)
self._key += String.fromCharCode((hexUpper << 4) + hexLower);
else
self._val += String.fromCharCode((hexUpper << 4) + hexLower);
self._byte = -2;
self._lastPos = pos;
} else {
// Only one hex character was available in this chunk
self._byte = hexUpper;
}
} else {
// We saw only one hex character so far
const hexLower = HEX_VALUES[chunk[pos++]];
if (hexLower === -1)
return -1;
if (self._inKey)
self._key += String.fromCharCode((self._byte << 4) + hexLower);
else
self._val += String.fromCharCode((self._byte << 4) + hexLower);
self._byte = -2;
self._lastPos = pos;
}
return pos;
}
function skipKeyBytes(self, chunk, pos, len) {
// Skip bytes if we've truncated
if (self._bytesKey > self.fieldNameSizeLimit) {
if (!self._keyTrunc) {
if (self._lastPos < pos)
self._key += chunk.latin1Slice(self._lastPos, pos - 1);
}
self._keyTrunc = true;
for (; pos < len; ++pos) {
const code = chunk[pos];
if (code === 61/* '=' */ || code === 38/* '&' */)
break;
++self._bytesKey;
}
self._lastPos = pos;
}
return pos;
}
function skipValBytes(self, chunk, pos, len) {
// Skip bytes if we've truncated
if (self._bytesVal > self.fieldSizeLimit) {
if (!self._valTrunc) {
if (self._lastPos < pos)
self._val += chunk.latin1Slice(self._lastPos, pos - 1);
}
self._valTrunc = true;
for (; pos < len; ++pos) {
if (chunk[pos] === 38/* '&' */)
break;
++self._bytesVal;
}
self._lastPos = pos;
}
return pos;
}
/* eslint-disable no-multi-spaces */
const HEX_VALUES = [
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
];
/* eslint-enable no-multi-spaces */
module.exports = URLEncoded;
|