Undo can reveal the password

[jthulhu]

When editing a password, doing undo twice right away reveals the password. This may lead to unwanted password leakage, by pressing undo many times to get to the original state.

[doolio]

Can you provide steps to reproduce this bug?

[jthulhu]

Sure. This bug issue was open long ago, but the bug still exists, although slightly differently than the version I reported: now undoing once is enough to reveal the password. More precisely, to reproduce the bug, follow these steps

• open the password store in Emacs with M-xpass
• open any entry, it shows •••••••••••• on the first line
• undo with M-xundo: this reveals the password.

[doolio]

OK, I've submitted PR #60 which fixes this issue but it may be too extreme as you will not be able to undo other changes in the buffer that you may want to.

[jthulhu]

This seems indeed a bit too extreme. The fact that you can accidentally reveal the password with undo is a problem only for those who actually use undo in these buffers (and that do so despite the mild risk). For this reason, I think that removing the undo altogether is counterproductive, because it "solves" a problem only for those who actually want to undo.

I think the proper solution would be to make the password visibility toggle not count as an undoable action, if possible.