Class: Nostr

Inherits:
Object
  • Object
show all
Defined in:
lib/nostr_ruby.rb

Overview

  • Ruby library to interact with the Nostr protocol

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key) ⇒ Nostr

Returns a new instance of Nostr.



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# File 'lib/nostr_ruby.rb', line 15

def initialize(key)
  hex_private_key =  if key[:private_key]&.include?('nsec')
    Nostr.to_hex(key[:private_key])
  else
    key[:private_key]
  end

  hex_public_key = if key[:public_key]&.include?('npub')
    Nostr.to_hex(key[:public_key])
  else
    key[:public_key]
  end

  if hex_private_key
    @private_key = hex_private_key
    group = ECDSA::Group::Secp256k1
    @public_key = group.generator.multiply_by_scalar(private_key.to_i(16)).x.to_s(16).rjust(64, '0')
  elsif hex_public_key
    @public_key = hex_public_key
  else
    raise 'Missing private or public key'
  end
end

Instance Attribute Details

#pow_difficulty_target ⇒ Object (readonly)

Returns the value of attribute pow_difficulty_target.



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# File 'lib/nostr_ruby.rb', line 13

def pow_difficulty_target
  @pow_difficulty_target
end

#private_key ⇒ Object (readonly)

Returns the value of attribute private_key.



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# File 'lib/nostr_ruby.rb', line 13

def private_key
  @private_key
end

#public_key ⇒ Object (readonly)

Returns the value of attribute public_key.



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# File 'lib/nostr_ruby.rb', line 13

def public_key
  @public_key
end

Class Method Details

.to_bech32(hex_key, hrp) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 56

def self.to_bech32(hex_key, hrp)
  custom_addr = CustomAddr.new
  custom_addr.scriptpubkey = hex_key
  custom_addr.hrp = hrp
  custom_addr.addr
end

.to_hex(bech32_key) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 51

def self.to_hex(bech32_key)
  public_addr = CustomAddr.new(bech32_key)
  public_addr.to_scriptpubkey
end

Instance Method Details

#bech32_keys ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 45

def bech32_keys
  bech32_keys = { public_key: Nostr.to_bech32(@public_key, 'npub') }
  bech32_keys[:private_key] = Nostr.to_bech32(@private_key, 'nsec') if @private_key
  bech32_keys
end

#build_close_event(subscription_id) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 247

def build_close_event(subscription_id)
  ['CLOSE', subscription_id]
end

#build_contact_list_event(contacts) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 166

def build_contact_list_event(contacts)
  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": 3,
    "tags": contacts.map { |c| ['p'] + c },
    "content": ''
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_deletion_event(events, reason = '') ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 201

def build_deletion_event(events, reason = '')
  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": 5,
    "tags": events.map{ |e| ['e', e] },
    "content": reason
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_dm_event(text, recipient_public_key) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 179

def build_dm_event(text, recipient_public_key)
  cipher = OpenSSL::Cipher::Cipher.new('aes-256-cbc')
  cipher.encrypt
  cipher.iv = iv = cipher.random_iv
  cipher.key = calculate_shared_key(recipient_public_key)
  encrypted_text = cipher.update(text)
  encrypted_text << cipher.final
  encrypted_text = "#{Base64.encode64(encrypted_text)}?iv=#{Base64.encode64(iv)}"
  encrypted_text = encrypted_text.gsub("\n", '')

  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": 4,
    "tags": [['p', recipient_public_key]],
    "content": encrypted_text
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_event(payload) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 115

def build_event(payload)
  event = sign_event(payload)
  ['EVENT', event]
end

#build_metadata_event(name, about, picture, nip05) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 120

def build_metadata_event(name, about, picture, nip05)
  data = {}
  data[:name] = name if name
  data[:about] = about if about
  data[:picture] = picture if picture
  data[:nip05] = nip05 if nip05
  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": 0,
    "tags": [],
    "content": data.to_json
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_note_event(text, channel_key = nil) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 138

def build_note_event(text, channel_key = nil)
  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": channel_key ? 42 : 1,
    "tags": channel_key ? [['e', channel_key]] : [],
    "content": text
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_notice_event(message) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 251

def build_notice_event(message)
  ['NOTICE', message]
end

#build_reaction_event(reaction, event, author) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 214

def build_reaction_event(reaction, event, author)
  raise 'Invalid reaction' unless ['+', '-'].include?(reaction) || reaction.match?(Unicode::Emoji::REGEX)
  raise 'Invalid author' unless event.is_a?(String) && event.size == 64
  raise 'Invalid event' unless author.is_a?(String) && author.size == 64

  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": 7,
    "tags": [['e', event], ['p', author]],
    "content": reaction
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_recommended_relay_event(relay) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 151

def build_recommended_relay_event(relay)
  raise 'Invalid relay' unless relay.start_with?('wss://') || relay.start_with?('ws://')

  event = {
    "pubkey": @public_key,
    "created_at": Time.now.utc.to_i,
    "kind": 2,
    "tags": [],
    "content": relay
  }

  event = sign_event(event)
  ['EVENT', event]
end

#build_req_event(filters) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 243

def build_req_event(filters)
  ['REQ', SecureRandom.random_number.to_s, filters]
end

#calculate_shared_key(other_public_key) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 63

def calculate_shared_key(other_public_key)
  ec = OpenSSL::PKey::EC.new('secp256k1')
  ec.private_key = OpenSSL::BN.new(@private_key, 16)
  recipient_key_hex = "02#{other_public_key}"
  recipient_pub_bn = OpenSSL::BN.new(recipient_key_hex, 16)
  secret_point = OpenSSL::PKey::EC::Point.new(ec.group, recipient_pub_bn)
  ec.dh_compute_key(secret_point)
end

#decrypt_dm(event) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 231

def decrypt_dm(event)
  data = event[1]
  sender_public_key = data[:pubkey] != @public_key ? data[:pubkey] : data[:tags][0][1]
  encrypted = data[:content].split('?iv=')[0]
  iv = data[:content].split('?iv=')[1]
  cipher = OpenSSL::Cipher::Cipher.new('aes-256-cbc')
  cipher.decrypt
  cipher.iv = Base64.decode64(iv)
  cipher.key = calculate_shared_key(sender_public_key)
  (cipher.update(Base64.decode64(encrypted)) + cipher.final).force_encoding('UTF-8')
end

#keys ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 39

def keys
  keys = { public_key: @public_key }
  keys[:private_key] = @private_key if @private_key
  keys
end

#match_pow_difficulty?(event_id) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/nostr_ruby.rb', line 255

def match_pow_difficulty?(event_id)
  @pow_difficulty_target.nil? || @pow_difficulty_target == [event_id].pack("H*").unpack("B*")[0].index('1')
end

#set_pow_difficulty_target(n) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 259

def set_pow_difficulty_target(n)
  @pow_difficulty_target = n
end

#sign_event(event) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 72

def sign_event(event)
  raise 'Invalid pubkey' unless event[:pubkey].is_a?(String) && event[:pubkey].size == 64
  raise 'Invalid created_at' unless event[:created_at].is_a?(Integer)
  raise 'Invalid kind' unless (0..29_999).include?(event[:kind])
  raise 'Invalid tags' unless event[:tags].is_a?(Array)
  raise 'Invalid content' unless event[:content].is_a?(String)

  serialized_event = [
    0,
    event[:pubkey],
    event[:created_at],
    event[:kind],
    event[:tags],
    event[:content]
  ]

  serialized_event_sha256 = nil
  if @pow_difficulty_target
    nonce = 1
    loop do
      nonce_tag = ['nonce', nonce.to_s, @pow_difficulty_target.to_s]
      nonced_serialized_event = serialized_event.clone
      nonced_serialized_event[4] = nonced_serialized_event[4] + [nonce_tag]
      serialized_event_sha256 = Digest::SHA256.hexdigest(JSON.dump(nonced_serialized_event))
      if match_pow_difficulty?(serialized_event_sha256)
        event[:tags] << nonce_tag
        break
      end
      nonce += 1
    end
  else
    serialized_event_sha256 = Digest::SHA256.hexdigest(JSON.dump(serialized_event))
  end

  private_key = Array(@private_key).pack('H*')
  message = Array(serialized_event_sha256).pack('H*')
  event_signature = Schnorr.sign(message, private_key).encode.unpack('H*')[0]

  event['id'] = serialized_event_sha256
  event['sig'] = event_signature
  event
end

#test_post_event(event, relay) ⇒ Object 



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# File 'lib/nostr_ruby.rb', line 263

def test_post_event(event, relay)
  response = nil
  ws = WebSocket::Client::Simple.connect relay
  ws.on :message do |msg|
    puts msg
    response = JSON.parse(msg.data)
    ws.close
  end
  ws.on :open do
    ws.send event.to_json
  end
  while response.nil? do
    sleep 0.1
  end
  response[0] == 'OK'
end