Rust crypto SDK parity for integration in element R

[BillCarsonFr]

https://github.com/matrix-org/matrix-rust-sdk/issues?q=is%3Aopen+is%3Aissue+milestone%3A%22Stabilize+the+crypto+crate%22

Notable points:

• Implement MSC3061: Sharing room keys for past messages  matrix-org/matrix-rust-sdk#580
• Device dehydration support matrix-org/matrix-rust-sdk#401
• Expose the Client::send method, adding a brief doccomment matrix-org/matrix-rust-sdk#40
• OTK fetching failure woes (attempting to establish Olm sessions too often) matrix-org/matrix-rust-sdk#281

[almereyda]

• [meta] Element Web's requirements for crypto-js matrix-org/matrix-rust-sdk#1016 (comment)

mentions

• key backup & cross-signing (and/or SSSS)
• Custom to-device message bindings (for MSC3401 VoIP)

for this, too.

element-hq/element-web#21972 (comment) also mirrors the cross-signing/SSSS and backup requirement.

[richvdh]

Looks like this issue has served its purpose.