nostr-gem/lib/nostr/crypto.rb
2023-02-25 17:37:58 +07:00

49 lines
1.2 KiB
Ruby

# frozen_string_literal: true
module Nostr
# Performs cryptographic operations on a +Nostr::Event+.
class Crypto
# Uses the private key to generate an event id and sign the event
#
# @api public
#
# @example Signing an event
# crypto = Nostr::Crypto.new
# crypto.sign(event, private_key)
# event.id # => an id
# event.sig # => a signature
#
# @param event [Event] The event to be signed
# @param private_key [String] 32-bytes hex-encoded private key.
#
# @return [Event] An unsigned event.
#
def sign_event(event, private_key)
event_digest = hash_event(event)
hex_private_key = Array(private_key).pack('H*')
hex_message = Array(event_digest).pack('H*')
event_signature = Schnorr.sign(hex_message, hex_private_key).encode.unpack1('H*')
event.id = event_digest
event.sig = event_signature
event
end
private
# Generates a SHA256 hash of a +Nostr::Event+
#
# @api private
#
# @param event [Event] The event to be hashed
#
# @return [String] A SHA256 digest of the event
#
def hash_event(event)
Digest::SHA256.hexdigest(JSON.dump(event.serialize))
end
end
end