Proof of concept implementation of Nostr NIP-03 OpenTimestamps Attestations for Events

Usage

With the following nostr event

json { "id": ..., "kind": ..., ..., ..., "ots": <base64-encoded OTS file data> }

rust let event_id = event_json["id"]; let ots = nostr_ots::timestamp_event(event_id).unwrap(); event_json["ots"] = ots;

Test

Test implementation against OpenTimestamps python client

```bash

$ echo "Proof of concept implementation of NIP-03" > example

$ shasum -a 256 example d6f3c7616621ea55fa99444dc82ce7eafed2e71352a0890882b2e42285b90724 example

$ cargo run --example stamp -- d6f3c7616621ea55fa99444dc82ce7eafed2e71352a0890882b2e42285b90724 example | base64 --decode >example.ots

$ ots info example.ots File sha256 hash: d6f3c7616621ea55fa99444dc82ce7eafed2e71352a0890882b2e42285b90724 Timestamp: -> append 35abd6957bb035a904df2a74d1287c56 sha256 prepend 63ebc438 append ba3242b113ee37d7 verify PendingAttestation('https://bob.btc.calendar.opentimestamps.org') -> append 77cf7970f11e52ec3531b27b44d856e7 sha256 prepend 63ebc439 append bd08b13e2e6f49f5 verify PendingAttestation('https://btc.calendar.catallaxy.com') -> append a2231bf8052e0f79947121c687b3f97e sha256 append b80ffca6f3ea6ad3e5a4bb0b0be819ba4753bc5a3a8987c46fa0fde76847a520 sha256 prepend 63ebc438 append cf1c91194578d4e3 verify PendingAttestation('https://finney.calendar.eternitywall.com') -> append ab64d01a5ebe068d205024e098a69feb sha256 prepend 1153c8b5ab758ff941eaf6507c3e774abd58a81089e86c8bbec137a0e36c6680 sha256 prepend 63ebc438 append 59e9634366c30207 verify PendingAttestation('https://alice.btc.calendar.opentimestamps.org') ```

TODO

• Support async other than blocking
• Better support of upstream library to generate timestamp
• ots client prepend some data before submitting the proof to avoid leaking the real hash
• General code improvement
• Create a struct holding the http client to avoid reinitializing every time
• Better integration with nostrs structs, if a crate providing general/standard struct/traits exists
• handle upgrade of the ots in an event json
• handle verify of the ots in the event json, outputs ots proof date
• use httptest for local testing