PGP invalid checksum appears on forwarded signed message

[martgil]

Description:

I noticed that invalid checksum appears on forwarded signed message. Meanwhile the signed message verification works.

There's also a typographical error which makes "}" as part of the rendered content but should be omitted.

flowcrypt-browser/extension/chrome/elements/pgp_block_modules/pgp-block-render-module.ts

Line 52 in aeda798

contentWithLink = `<div class="pgp-invalid-checksum">${Lang.pgpBlock.invalidCheckSum}</div>${contentWithLink}}`;

Step to reproduce:

1. User 1 send signed message User 2.
2. User forwards the signed message as plain text using (Gmail forward) to User 3.
3. User 3 sees the following message above using FlowCrypt browser.

[martgil]

Hi @sosnovsky I'd like to consult to you what's best for this one. It's a forwarded signed message the verification is good to be true but the checksum mismatch is expected since the message is not meant for the receiver of the forwarded message.

If this is correctly working, then issue would only be that the trailing "}" of the rendered content.

[martgil]

Recipient of the forwarded signed message may panic if they see the warning description for the forwarded signed message they receive.

[sosnovsky]

When trying to reproduce this error, I got another error, but it was shown only for initial message.
Maybe for Mart's case we can also show checksum mismatch detected error label only for initial message, not for full forward message? In this case recipient will understand that it relates only to the initial message.