E2E: Cross-sign on login

[lampholder]

This should be the final piece in the puzzle - implementing cross-sign on login once bidirectional verification back-end is in place. (1)

[uhoreg]

I'm not sure how "Cross-sign on login" relates to cross-signing in general, but for cross-signing, the work needed is:

• spec
  • figure out the federation endpoints
  • decide on any other outstanding issues
  • get the MSC accepted
• synapse
  • see Implement cross-signing proposal matrix-org/synapse#4110
• libolm: no changes needed
• js-sdk (and android-sdk, ios-sdk)
  • functions to sign/verify attestations
  • send/receive/store attestations
  • calculate trust status based on attestations
• react-sdk (and riot-android, riot-ios)
  • general UI work

[ara4n]

Progress on this one is actually being tracked at element-hq/element-web#9631

[Valodim]

guess this one's done?