The whitelisting was hidden by the last release. You can whitelist by setting the desired blocking mode for the URL specifically. If you want to whitelist an URL just give it an "allow everything". You can still whitelist a site from the notifications. I should definitely clarify the description...

Adding an URL specific block mode:
go to options, click on the triangle next to the blocking mode, enter the domain you want to whitelist, click on the plus, now you can set the blocking mode for the domain.

PS: you can still enter something in the white list by checking expert mode, open the export settings page and entering something in the whitelist field.

EDIT: Is the screenshot of the settings not explanatory enough?
EDIT2: It's easier for us to communicate on github. If you have any questions - just open an issue. Here the communication is slow and not relyable.

EDIT3: please try version 0.4.4 - there the whitelist is available again.

Can you please file an issue at https://github.com/kkapsner/CanvasBlocker/issues with more details. I already know that there are problem but I'm not able to spot them because I never had a reproduction scenario.

EDIT: Have you tried any of the Beta versions? https://github.com/kkapsner/CanvasBlocker/releases/
EDIT: Please try version 0.4.4

I will look into this issue (progress can be seen here: https://github.com/kkapsner/CanvasBlocker/issues/161). The faking is working fine on https://browserleaks.com/canvas

EDIT: They are using a very big canvas (400 000 pixels) to do the fingerprinting. It works fine if you disable the "Maximal fake size" ("Maximale Vortäuschgröße") setting. I will adjust the recommendation accordingly.

This issue was already reported to me. But I'm not able to reproduce it on my end. Please create a new issue on github with the informations to reproduce the problem (Firefox version, installed Addons, CB settings, URL to the not working image and if the problem is still present when a fresh profile is used): https://github.com/kkapsner/CanvasBlocker/issues/new

You can look at the code (either at https://github.com/kkapsner/CanvasBlocker/ of you can download the xpi-file, change the extension to zip and look at the content). It does not store any private information or sends anything to a server.

UPDATE: I just realized I did not answer the question. The addon does not need access to login information (and does not use it). But there is no techical difference between the information the addon needs access to (the canvas and JS that are used for fingerprinting) and other information. I would gladly only take the permission to access the information that I only need - it's just not possible.

Thanks for your finding. The faking is working fine - just the display of the icon is confused by this site. This will be fixed in the next release (see https://github.com/kkapsner/CanvasBlocker/issues/149 for reference - btw it's much easier for us to communicate on github via issues than AMO)

Since this is a minor issue there will not be a release for this alone.

Please recheck your Firefox version and try to add it again. Version 0.4.2 should also run with Firefox 52.4.1