Cyberchef: Bug report: AES Encryption with cipher text of null string appended?

[jiegec]

Summary

Encrypting a 16-byte text results in its own 16-byte cipher text with cipher text of null string appended.

Example

Recipe 1

Encrypt hex "00000000000000000000000000000000" with AES-128-ECB with key hex "00000000000000000000000000000000" results in "66e94bd4ef8a2c3b884cfa59ca342b2e0143db63ee66b0cdff9f69917680151e".

Expected output was "66e94bd4ef8a2c3b884cfa59ca342b2e". But the output was "66e94bd4ef8a2c3b884cfa59ca342b2e" + "0143db63ee66b0cdff9f69917680151e". It can be confirmed that "0143db63ee66b0cdff9f69917680151e" is the cipher text of a null string.

Recipe 2

[imhotepisinvisible]

This doesn't appear to be a bug. Forge, the crypto library used by this operation, explicitly states that "CBC and ECB modes use PKCS#7 padding as default" which is typical for these operation modes. It can be seen that 0143db63ee66b0cdff9f69917680151e is the cipher text of a full padding block of 0x10 bytes: recipe

It might be useful though if these operations included the option to disable padding.

[jiegec]

Many thanks. Padding mode should be changeable then.