From 97d866582624738fcce535c6f7f6c1599dd3a255 Mon Sep 17 00:00:00 2001
From: Christopher Vollick <0@psycoti.ca>
Date: Wed, 23 Jun 2021 15:23:07 -0400
Subject: [PATCH] Various Electrum Checks and Fixes

There were some issues with Electrum, and we lost a bit of confidence,
so I built these to help with that.

bin/check_electrum_wallet_completeness
- This one is meant to be run in cron. It checks for addresses we've
  given a user that Electrum doesn't know we have. It just prints out,
  so we get an email and can go look.
  The purpose of this is to know before our users that we're missing
  something.

bin/detect_duplicate_addrs
- This one is meant to be run in cron. It looks through the addresses
  that users has have been given to make sure the same address hasn't
  been given out to more than one person.
  It just prints out the issues, so we'll be notified and can take a
  look

bin/correct_duplicate_addrs
- This is one potential solution that can be run in response to
  duplicate addresses.
  Since I'm expecting an email from bin/detect_duplicate_addrs, this
  takes as input the text that was sent to us.
  It goes through each address and re-assigns it away from all users,
  parking the addresses on the support account so we still get notified
  when people send money, etc
  Because it takes output as input, they could be piped together in
  theory, but I never tested that because I assume some investigation
  would be warranted

bin/reassert_electrum_notification
- This script goes through every bitcoin address that's been given to a
  customer and makes sure that electrum knows to tell us about changes
  to that address
---
 bin/check_electrum_wallet_completeness | 22 +++++++++++++++
 bin/correct_duplicate_addrs            | 38 ++++++++++++++++++++++++++
 bin/detect_duplicate_addrs             | 12 ++++++++
 bin/reassert_electrum_notification     | 29 ++++++++++++++++++++
 lib/electrum.rb                        |  8 ++++++
 lib/redis_addresses.rb                 | 24 ++++++++++++++++
 6 files changed, 133 insertions(+)
 create mode 100644 bin/check_electrum_wallet_completeness
 create mode 100644 bin/correct_duplicate_addrs
 create mode 100755 bin/detect_duplicate_addrs
 create mode 100644 bin/reassert_electrum_notification
 create mode 100644 lib/redis_addresses.rb

diff --git a/bin/check_electrum_wallet_completeness b/bin/check_electrum_wallet_completeness
new file mode 100644
index 0000000000000000000000000000000000000000..ddcdec01d9bcd90b9964b5b5d73a4b7ce823ed21
--- /dev/null
+++ b/bin/check_electrum_wallet_completeness
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require 'redis'
+require 'dhall'
+require_relative '../lib/redis_addresses'
+require_relative '../lib/electrum'
+
+config =
+	Dhall::Coder
+	.new(safe: Dhall::Coder::JSON_LIKE + [Symbol, Proc])
+	.load(ARGV[0], transform_keys: :to_sym)
+
+redis = Redis.new
+electrum = Electrum.new(**config)
+
+electrum_addrs = electrum.listaddresses
+
+get_addresses_with_users(redis).each do |addr, keys|
+	unless electrum_addrs.include?(addr)
+		puts "The address #{addr} (included in #{keys.join(", ")}) isn't included in electrum's list"
+	end
+end
diff --git a/bin/correct_duplicate_addrs b/bin/correct_duplicate_addrs
new file mode 100644
index 0000000000000000000000000000000000000000..9d5550a91363fd50edfb448f7fcf36fa0e57dbc5
--- /dev/null
+++ b/bin/correct_duplicate_addrs
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+# This is meant to be run with the output of detect_duplicate_addrs on stdin
+# The assumption is that some logging will dump that, and then someone will
+# run this after looking into why
+# Theoretically they could be piped together directly for automated fixing
+
+require 'redis'
+
+redis = Redis.new
+
+customer_id = ENV['DEFAULT_CUSTOMER_ID']
+unless customer_id
+	puts "The env-var DEFAULT_CUSTOMER_ID must be set to the ID of the customer who will receive the duplicated addrs, preferably a support customer or something linked to notifications when stray money is sent to these addresses"
+	exit 1
+end
+
+
+STDIN.each_line do |line|
+	match = line.match(/^(\w+) is used by the following \d+ keys: (.*)/)
+	unless match
+		puts "The following line can't be understood and is being ignored"
+		puts "  #{line}"
+		next
+	end
+
+	addr = match[1]
+	keys = match[2].split(" ")
+
+	# This is the customer ID of the support chat
+	# All duplicates are moved to the support addr so we still hear when people
+	# send money there
+	redis.sadd("jmp_customer_btc_addresses-#{customer_id}", addr)
+
+	keys.each do |key|
+		redis.srem(key, addr)
+	end
+end
diff --git a/bin/detect_duplicate_addrs b/bin/detect_duplicate_addrs
new file mode 100755
index 0000000000000000000000000000000000000000..309ae1e7193e95c74ab5acdfa97b698b30cc8b7e
--- /dev/null
+++ b/bin/detect_duplicate_addrs
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require 'redis'
+require_relative '../lib/redis_addresses'
+
+redis = Redis.new
+
+get_addresses_with_users(redis).each do |addr, keys|
+	if keys.length > 1
+		puts "#{addr} is used by the following #{keys.length} keys: #{keys.join(" ")}"
+	end
+end
diff --git a/bin/reassert_electrum_notification b/bin/reassert_electrum_notification
new file mode 100644
index 0000000000000000000000000000000000000000..83bc1d2705ae660c24be87f5c91b84d8cf620962
--- /dev/null
+++ b/bin/reassert_electrum_notification
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'redis'
+require 'dhall'
+require_relative '../lib/redis_addresses'
+require_relative '../lib/electrum'
+
+config =
+	Dhall::Coder
+	.new(safe: Dhall::Coder::JSON_LIKE + [Symbol, Proc])
+	.load(ARGV[0], transform_keys: :to_sym)
+
+redis = Redis.new
+electrum = Electrum.new(**config)
+
+get_addresses_with_users(redis).each do |addr, keys|
+	match = keys.first.match(/.*-(\d+)$/)
+	unless match
+		puts "Can't understand key #{keys.first}, skipping"
+		next
+	end
+
+	customer_id = match[1]
+	url = "https://pay.jmp.chat/electrum_notify?address=#{addr}&customer_id=#{customer_id}"
+
+	unless electrum.notify(addr, url)
+		puts "Failed to setup #{addr} to notify #{url}. Skipping"
+	end
+end
diff --git a/lib/electrum.rb b/lib/electrum.rb
index 1cdaf908d6635df2dafd1b35587165af0e5f389e..f4489ebd78b3a544b35b7787f56c72bc635975ee 100644
--- a/lib/electrum.rb
+++ b/lib/electrum.rb
@@ -27,6 +27,14 @@ class Electrum
 		rpc_call(:get_tx_status, txid: tx_hash)["result"]
 	end
 
+	def listaddresses
+		rpc_call(:listaddresses, {})["result"]
+	end
+
+	def notify(address, url)
+		rpc_call(:notify, address: address, URL: url)["result"]
+	end
+
 	class Transaction
 		def initialize(electrum, tx_hash, tx)
 			@electrum = electrum
diff --git a/lib/redis_addresses.rb b/lib/redis_addresses.rb
new file mode 100644
index 0000000000000000000000000000000000000000..17a5a1e10b273bef430b9597c102217350cc198f
--- /dev/null
+++ b/lib/redis_addresses.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require "redis"
+
+# This returns a hash
+# The keys are the bitcoin addresses, the values are all of the keys which
+#   contain that address
+# If there are no duplicates, then each value will be a singleton list
+def get_addresses_with_users(redis)
+	addrs = Hash.new { |h, k| h[k] = [] }
+
+	# I picked 1000 because it made a relatively trivial case take 15 seconds
+	#   instead of forever.
+	# Basically it's "how long does each command take"
+	# The lower it is (default is 10), it will go back and forth to the client a
+	#   ton
+	redis.scan_each(match: "jmp_customer_btc_addresses-*", count: 1000) do |key|
+		redis.smembers(key).each do |addr|
+			addrs[addr] << key
+		end
+	end
+
+	addrs
+end