CODEWITHSUNDEEP
c#php
Curtis
Curtis

Reputation: 2704

Extra bytes added using rijndael decrypt

I've ported over some C# to PHP as to which I thought was successful, it turns out that the PHP version of phpseclib is appending extra random bytes to my result.

Here's my C# result in what it should be:

C# result

And here's my PHP result, as you can see it appends random bytes to the string.

enter image description here

The PHP functionality I'm using to decode is:

$rijndael = new Rijndael();
$rijndael->setKey(hex2bin($rgbKey));
$rijndael->setIV(hex2bin($rgbIv));
$rijndael->setKeyLength(256);
$rijndael->setBlockLength(128);
$rijndael->disablePadding();

$result = $rijndael->decrypt(rtrim(hex2bin(implode("", $hexdata))));

The C# function that's decoding is:

int num2 = 0;
int count1 = rijndaelManaged.BlockSize / 8;
byte[] buffer4 = new byte[count1];
fileStream.Seek((long)Start, SeekOrigin.Begin);
using (CryptoStream cryptoStream = new CryptoStream((Stream)memoryStream, decryptor, CryptoStreamMode.Write)) {
    while (fileStream.Position < fileStream.Length - 128L) {
        int count2 = fileStream.Read(buffer4, 0, count1);
        num2 += count2;
        cryptoStream.Write(buffer4, 0, count2);
        if (count2 <= 0)
            break;
    }
    cryptoStream.FlushFinalBlock();
    cryptoStream.Close();
}
fileStream.Close();

If anyone could point me in the right direction to prevent the extra bytes that'd be great, the other thing I should note is the amount of extra bytes vary based on the file which is decoded

Upvotes: 1

Views: 128

Answers (1)

Curtis
Curtis

Reputation: 2704

It appears that removing $rijndael->disablePadding(); fixed the problem!

Upvotes: 1

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