51 lines
2.4 KiB
Markdown
51 lines
2.4 KiB
Markdown
# Onionr Protocol Spec v2
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A P2P platform for Tor & I2P
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# Overview
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Onionr is an encrypted microblogging & mailing system designed in the spirit of Twitter.
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There are no central servers and all traffic is peer to peer by default (routed via Tor or I2P).
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User IDs are simply Tor onion service/I2P host id + Ed25519 key fingerprint.
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Private blocks are only able to be read by the intended peer.
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All traffic is over Tor/I2P, connecting only to Tor onion and I2P hidden services.
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## Goals:
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• Selective sharing of information
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• Secure & semi-anonymous direct messaging
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• Forward secrecy
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• Defense in depth
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• Data should be secure for years to come
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• Decentralization
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* Avoid browser-based exploits that plague similar software
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* Avoid timing attacks & unexpected metadata leaks
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## Protocol
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Onionr nodes use HTTP (over Tor/I2P) to exchange keys, metadata, and blocks. Blocks are identified by their sha3_256 hash. Nodes sync a table of blocks hashes and attempt to download blocks they do not yet have from random peers.
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Blocks may be encrypted using Curve25519.
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## Connections
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When a node first comes online, it attempts to bootstrap using a default list provided by a client.
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When two peers connect, they exchange Ed25519 keys (if applicable) then Salsa20 keys.
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Salsa20 keys are regenerated either every X many communications with a peer or every X minutes.
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Every 100kb or every 2 hours is a recommended default.
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All valid requests with HMAC should be recorded until used HMAC's expiry to prevent replay attacks.
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Peer Types
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* Friends:
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* Encrypted ‘friends only’ posts to one another
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* Usually less strict rate & storage limits
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* Strangers:
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* Used for storage of encrypted or public information
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* Can only read public posts
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* Usually stricter rate & storage limits
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## Spam mitigation
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To send or receive data, a node can optionally request that the other node generate a hash that when in hexadecimal representation contains a random string at a random location in the string. Clients will configure what difficulty to request, and what difficulty is acceptable for themselves to perform. Difficulty should correlate with recent network & disk usage and data size. Friends can be configured to have less strict (to non existent) limits, separately from strangers. (proof of work).
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Rate limits can be strict, as Onionr is not intended to be an instant messaging application. |