pad and unpad message everywhere
attachment not padded for opengroup onlypull/1604/head
Audric Ackermann
4 years ago
parent
7b96aba1bf
commit
c063848167
@ -0,0 +1,94 @@
|
||||
/**
|
||||
* This file is used to pad message buffer and attachments
|
||||
*/
|
||||
const PADDING_BYTE = 0x00;
|
||||
|
||||
/**
|
||||
* Unpad the buffer from its padding.
|
||||
* An error is thrown if there is no padding.
|
||||
* A padded buffer is
|
||||
* * whatever at start
|
||||
* * ends with 0x80 and any number of 0x00 until the end
|
||||
*/
|
||||
export function removeMessagePadding(paddedData: ArrayBuffer): ArrayBuffer {
|
||||
const paddedPlaintext = new Uint8Array(paddedData);
|
||||
window.log.info('Removing message padding...');
|
||||
for (let i = paddedPlaintext.length - 1; i >= 0; i -= 1) {
|
||||
if (paddedPlaintext[i] === 0x80) {
|
||||
const plaintext = new Uint8Array(i);
|
||||
plaintext.set(paddedPlaintext.subarray(0, i));
|
||||
return plaintext.buffer;
|
||||
} else if (paddedPlaintext[i] !== PADDING_BYTE) {
|
||||
throw new Error('Invalid padding');
|
||||
}
|
||||
}
|
||||
|
||||
throw new Error('Invalid padding');
|
||||
}
|
||||
|
||||
/**
|
||||
* Add padding to a message buffer
|
||||
* @param messageBuffer The buffer to add padding to.
|
||||
*/
|
||||
export function addMessagePadding(messageBuffer: Uint8Array): Uint8Array {
|
||||
window.log.info('Adding message padding...');
|
||||
|
||||
const plaintext = new Uint8Array(getPaddedMessageLength(messageBuffer.byteLength + 1) - 1);
|
||||
plaintext.set(new Uint8Array(messageBuffer));
|
||||
plaintext[messageBuffer.byteLength] = 0x80;
|
||||
|
||||
return plaintext;
|
||||
}
|
||||
|
||||
function getPaddedMessageLength(originalLength: number): number {
|
||||
const messageLengthWithTerminator = originalLength + 1;
|
||||
let messagePartCount = Math.floor(messageLengthWithTerminator / 160);
|
||||
|
||||
if (messageLengthWithTerminator % 160 !== 0) {
|
||||
messagePartCount += 1;
|
||||
}
|
||||
|
||||
return messagePartCount * 160;
|
||||
}
|
||||
|
||||
/**
|
||||
*
|
||||
* If the attachment has padding, remove the padding and return the unpad attachment
|
||||
|
||||
*/
|
||||
export function getUnpaddedAttachment(
|
||||
data: ArrayBuffer,
|
||||
unpaddedExpectedSize: number
|
||||
): ArrayBuffer | null {
|
||||
window.log.info('Removing attachment padding...');
|
||||
|
||||
// to have a padding we must have a strictly longer length expected
|
||||
if (data.byteLength <= unpaddedExpectedSize) {
|
||||
return null;
|
||||
}
|
||||
const dataUint = new Uint8Array(data);
|
||||
for (let i = unpaddedExpectedSize; i < data.byteLength; i++) {
|
||||
if (dataUint[i] !== PADDING_BYTE) {
|
||||
return null;
|
||||
}
|
||||
}
|
||||
|
||||
return data.slice(0, unpaddedExpectedSize);
|
||||
}
|
||||
|
||||
export function addAttachmentPadding(data: ArrayBuffer): ArrayBuffer {
|
||||
const originalUInt = new Uint8Array(data);
|
||||
window.log.info('Adding attchment padding...');
|
||||
|
||||
const paddedSize = Math.max(
|
||||
541,
|
||||
Math.floor(Math.pow(1.05, Math.ceil(Math.log(originalUInt.length) / Math.log(1.05))))
|
||||
);
|
||||
const paddedData = new ArrayBuffer(paddedSize);
|
||||
const paddedUInt = new Uint8Array(paddedData);
|
||||
|
||||
paddedUInt.fill(PADDING_BYTE, originalUInt.length);
|
||||
paddedUInt.set(originalUInt);
|
||||
|
||||
return paddedUInt.buffer;
|
||||
}
|
||||
@ -1,45 +0,0 @@
|
||||
/**
|
||||
* Unpad the buffer from its padding.
|
||||
* An error is thrown if there is no padding.
|
||||
* A padded buffer is
|
||||
* * whatever at start
|
||||
* * ends with 0x80 and any number of 0x00 until the end
|
||||
*/
|
||||
export function removeMessagePadding(paddedData: ArrayBuffer): ArrayBuffer {
|
||||
const paddedPlaintext = new Uint8Array(paddedData);
|
||||
|
||||
for (let i = paddedPlaintext.length - 1; i >= 0; i -= 1) {
|
||||
if (paddedPlaintext[i] === 0x80) {
|
||||
const plaintext = new Uint8Array(i);
|
||||
plaintext.set(paddedPlaintext.subarray(0, i));
|
||||
return plaintext.buffer;
|
||||
} else if (paddedPlaintext[i] !== 0x00) {
|
||||
throw new Error('Invalid padding');
|
||||
}
|
||||
}
|
||||
|
||||
throw new Error('Invalid padding');
|
||||
}
|
||||
|
||||
/**
|
||||
* Add padding to a message buffer
|
||||
* @param messageBuffer The buffer to add padding to.
|
||||
*/
|
||||
export function addMessagePadding(messageBuffer: Uint8Array): Uint8Array {
|
||||
const plaintext = new Uint8Array(getPaddedMessageLength(messageBuffer.byteLength + 1) - 1);
|
||||
plaintext.set(new Uint8Array(messageBuffer));
|
||||
plaintext[messageBuffer.byteLength] = 0x80;
|
||||
|
||||
return plaintext;
|
||||
}
|
||||
|
||||
function getPaddedMessageLength(originalLength: number): number {
|
||||
const messageLengthWithTerminator = originalLength + 1;
|
||||
let messagePartCount = Math.floor(messageLengthWithTerminator / 160);
|
||||
|
||||
if (messageLengthWithTerminator % 160 !== 0) {
|
||||
messagePartCount += 1;
|
||||
}
|
||||
|
||||
return messagePartCount * 160;
|
||||
}
|
||||
Loading…
Reference in New Issue