Set AES strength to 256 bit

[pmario]

This PR fixes issue #8248

• [IDEA] Set the default encryption to AES 256 - currently it is 128 #8248

This PR changes the default AES encryption setting from 128 bit to 256 bit.

I did the following tests Windows 11 - FF latest

• Download emtpy.html from tiddlywiki.com which uses current defaults 128 bit
• Create some content
• Save encrypted as: aes-128.html
• Create aes-256.html with this PR
• Create some content
• Save encrypted as: aes-256.html

Import decryption test

• Import aes-256.html into aes-128.html -> Decryption and import works
• Import aes-128.html into eas-256.html -> Decryption and import works

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated (UTC)
tiddlywiki5	✅ Ready (Inspect)	Visit Preview	Jun 10, 2024 11:03am

[Jermolene]

Hi @pmario I'm happy with the idea but think it is important that we lay out the backwards compatibility implications. For example, can older versions of TiddlyWiki still open a 256-bit encrypted wiki?

[pmario]

I just did some drag & drop import test to archived empty.html wikis

AES-128 (created with TW v5.3.3) and AES-256 (created with this PR) both work

• TW v5.3.3 -> both work
• TW v5.3.0 -> both work
• TW v5.2.7 -> both work
• TW v5.2.4 -> both work
• TW v5.2.3 -> both work
• TW v5.2.2 -> both work

Neither AES-128 created with TW v5.3.3 nor AES-256 with PR works. -> So backwards compatibility was already broken.

• TW v5.2.1 -> none works
• TW v5.2.0 -> none works
• TW v5.1.23 -> none works

It does not even matter if there is a password. So JSON decode may be broken.

[pmario]

• Created an encrypted wiki with TW v5.1.23 and imported it to v5.3.3 and v5.3.4-pre -> works
• Created an encrypted wiki with TW v5.2.7 and imported it to v5.3.3 and v5.3.4-pre -> works

[Jermolene]

TW v5.3.3 -> both work

Thanks @pmario I am afraid I don't understand this part. Could you explain the test you performed in more detail?

[pmario]

• As I wrote I did create 2 wikis.
• Both are saved encrypted.
• One wiki created from TW v5.3.3, default AES-128
• one created with TW v5.3.4-pre, default AES-256

The I did take both wikis and import them into the empty wikis listed in the TW archive as shown above. Importing the encrypted wikis works as described above.

AES-128 v5.3.3 and AES-256 v5.3.4-pre can not be imported to older wikis starting with TW v5.2.1

This PR does not cause this problem. The problem has been there with v5.3.3 already.

[pmario]

@Jermolene -- I found the changes that caused the problem

• Importing/upgrading from encrypted single file wikis is broken since v5.2.0 #6330
• Commit: 60187dc