Error: invalid plaintext size (must be multiple of 16 bytes)

[shiqikai]

aes-js version: 3.1.2.
why should the length of plaintext in CBC be 16?

[ricmoo]

CBC Operates against blocks, so the data length must be a multiple of 16.

See the CBC section here: https://en.m.wikipedia.org/wiki/Block_cipher_mode_of_operation

Hope this helps. :)

[fxqy]

How to solve this problem, I also encountered this pit

[fxqy]

I don't know how to use it gracefully.Please help me write a better code.
------------------------------------------My code--------------------------------------------
function aesEcpt(text, pwd) {
var shp = sha256_digest(pwd);
var key = [];
var iv = [];
for (var i = 0; i < 32; i++) {
var itm = shp.charCodeAt(i);
if (i < 16)
key.push(itm);
else
iv.push(itm);
}
var textBytes = aesjs.utils.utf8.toBytes(text);
var aesCbc = new aesjs.ModeOfOperation.cbc(key, iv);
var encryptedBytes = aesCbc.encrypt(textBytes);
var encryptedHex = aesjs.utils.hex.fromBytes(encryptedBytes);
return encryptedHex;
}
function aesDcpt(text, pwd) {
var shp = sha256_digest(pwd);
var key = [];
var iv = [];
for (var i = 0; i < 32; i++) {
var itm = shp.charCodeAt(i);
if (i < 16)
key.push(itm);
else
iv.push(itm);
}
var encryptedBytes = aesjs.utils.hex.toBytes(text);
var aesCbc = new aesjs.ModeOfOperation.cbc(key, iv);
var decryptedBytes = aesCbc.decrypt(encryptedBytes);
var decryptedText = aesjs.utils.utf8.fromBytes(decryptedBytes);
return decryptedText;
}

[zhbzhbzhbz]

But when I'm using ECB mode, this error occurs too.
And in Java, the bytes array is not limited to 16*N bytes.

[RokerHRO]

Perhaps Cipher Text Stealing should be implemented in CBC mode, to support arbitrary plaintext lengths:

https://en.wikipedia.org/wiki/Ciphertext_stealing

[kishandonga]

use the below functions, it will help in this issue

aesjs.padding.pkcs7.pad()
aesjs.padding.pkcs7.strip()