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How to grant access to a website to extract canvas data without going to that website

  • 4 replies
  • 0 have this problem
  • 9 views
  • Last reply by cor-el

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I can't grant access to a website because it's totally borked without canvas data, and keeps going on an infinite loading loop. This loading loop prevents me from having enough time to grant the permission, so I need to grant the permission to this website without actually visiting it.

I can't grant access to a website because it's totally borked without canvas data, and keeps going on an infinite loading loop. This loading loop prevents me from having enough time to grant the permission, so I need to grant the permission to this website without actually visiting it.

All Replies (4)

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Do you have enabled "Resist Fingerprinting" as that is a possible cause for Canvas issues?

Can you post a link to a publicly accessible page (i.e. no authentication or signing on required)?


You can try to add the canvas exception via the Browser Console. You need to enable the command-line for the console.

Replace the https://xxxx with the correct origin (only protocol and hostname).

Services.perms.addFromPrincipal(
  Services.scriptSecurityManager.createContentPrincipalFromOrigin("https://xxxx"),
  "canvas", 1
);

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cor-el said

Do you have enabled "Resist Fingerprinting" as that is a possible cause for Canvas issues? Can you post a link to a publicly accessible page (i.e. no authentication or signing on required)?

You can try to add the canvas exception via the Browser Console. You need to enable the command-line for the console.

Replace the https://xxxx with the correct origin (only protocol and hostname).

Services.perms.addFromPrincipal(
  Services.scriptSecurityManager.createContentPrincipalFromOrigin("https://xxxx"),
  "canvas", 1
);

It seems like perhaps this isn't the issue after all. I am still having the same issue. I've attached a picture that might be helpful. I used the browser console you mentioned to capture some logged info in a picture while the website was looping for a couple of seconds.

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It would help others if you gave a URL so others can click to see what happens.

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You would have to check the Requests in the Web Console or in the Network Monitor to see what is going on.