Support scanning URL-based sync setup codes

[CDRussell]

Task/Issue URL: https://app.asana.com/1/137249556945/project/72649045549333/task/1209921186465304?focus=true

Description

#5944 allows the barcodes to be rendered as URL-based; this PR is the other side of the coin in adding support for scanning URL-based sync setup barcodes.

A note on feature flagging

For feature flagging around URL-based barcodes, I’ve separated out the ability to render them vs the ability to scan them. I think this will help the logistics around rolling it out, but sense-check that for me.

Feature flag	Description	Default state
syncSetupBarcodeIsUrlBased	Whether to render URL-based or plain barcodes	Off by default
canScanUrlBasedSyncSetupBarcodes	Whether we can scan URL-based codes	On by default (it’s a kill-switch

Steps to test this PR

You’ll need two devices, at least one of them being a real device so you can scan the barcode using its camera.

Scanning a connect code

• Log out of sync on both devices
• Choose Sync with another device on both
• Scan the barcode using the system camera first, to verify you are dealing with a URL-based barcode
• Scan the barcode from inside sync settings; verify sync sets up correctly

Scanning an exchange code

• Log out of sync on a physical device; stay logged in on the other
• Choose Sync with another device on both
• Using physical device, scan the barcode using the system camera first, to verify you are dealing with a URL-based barcode
• Using physical device, scan the barcode from inside sync settings; verify sync sets up correctly

Scanning a plaintext recovery code

• Log out of sync on a physical device; stay logged in on the other
• On the logged-in device, disable exchangeKeysToSyncWithAnotherDevice
• Choose Sync with another device on both devices
• Using physical device, scan the barcode using the system camera first, and verify you are not dealing with a URL-based barcode; this should be just the b64-encoded recovery code (recovery codes aren’t allowed in URLs, so disabling exchangeKeysToSyncWithAnotherDevice means URL-based codes won’t show either)
• Using physical device, scan the barcode from inside sync settings; verify sync sets up correctly

Scanning a URL-based recovery code

This isn’t acceptable so we won’t generate URLs containing recovery codes, but let’s test what happens if one is scanned. Barcode for testing what happens if you scan a recovery code inside a URL

• Log out of sync on a physical device (don’t need the other device for this test)
• Choose Sync with another device on the physical device
• Using physical device, scan the barcode linked above from inside sync settings; verify sync is not set up and you see an error message. In the logs, you’ll see Recovery code found inside a URL which is not acceptable

[CDRussell]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Support scanning URL-based sync setup codes #5957 👈 (View in Graphite)
• Support rendering URLs inside sync barcodes #5944
• develop

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[CDRussell]

now takes in the parsed code so we don’t have to parse it from JSON twice any more