Multisig: same order of public keys produces different address (vs coinb.in/#newMultiSig)

[ramontayag]

Not sure if this is a bug or I'm missing something.

I'm attempting to generate the same addresses as a multisig Electrum wallet using this library. When I enter the public keys into coinb.in of each address generated in Electrum, I get the same address as the one in Electrum, as long as I lexicographically order the public keys.

Using this library, I am not able to generate the same addresses. Here's the script I'm using:

require "btcruby"

# For context, not actually used in the script below.
cosigners = [
  {
    electrum_seed: "hotel congress unable service silver wool fabric ski buffalo orbit damp enjoy",
    master_public_key: "xpub661MyMwAqRbcGHY2QrfyiUyvSv93zCQN8Cv3eXFB3ivnq7SQ6TLUJueJnGZKR8r8CQ5cLsGrr9D71uwAW9RLKqFyUybARtbbqg1kiHopBsZ",
  },
  {
    electrum_seed: "trust diary skull hidden album awesome lady zoo polar gorilla alley credit",
    master_public_key: "xpub6D4K8Hb6sMZwwtbk6p94RnRewTb6PykJc1zZwB3GUozGSNXLnTdL2T8uXRehiD9d5Dis3bDpJCvR3pFZcYUu2xpPj5Z73oFNUUQKwkFTewo",
  },
]

# Copied from electrum 1-of-2 multisig wallet using the keys above. public_keys order is as shown in the address' "details" window of Electrum.
addresses = {
  0 => {
    address: "3GbE5Hn5NNfAbkk33AquoZqtoehkDDBEZn",
    public_keys: [
      "02c71e2fd1793943296f2c708ee44d0c7df113b3d9f6808180801835d510beb794",
      "036822f8013573775f7cb0c9aa1cbf7fba9b59480af59415685328a334b5f5c369",
    ],
    redeem_script: "512102c71e2fd1793943296f2c708ee44d0c7df113b3d9f6808180801835d510beb79421036822f8013573775f7cb0c9aa1cbf7fba9b59480af59415685328a334b5f5c36952ae",
  },
  4 => {
    address: "35gx2GzbtVy116Ai2kop8u95xWVHYfFPne",
    public_keys: [
      "03b064e3adf933622eff9b33e7dbc881e1bc9ec3030f96bf0ddd53cabd862adf7c",
      "0228f4d23588f5dd93ad64c1d1502f43c779e9d3811fcbe8af5f54faf585f68ece",
    ],
    redeem_script: "51210228f4d23588f5dd93ad64c1d1502f43c779e9d3811fcbe8af5f54faf585f68ece2103b064e3adf933622eff9b33e7dbc881e1bc9ec3030f96bf0ddd53cabd862adf7c52ae",
  },
  9 => {
    address: "3C1KyYDMg8woFnZZXqfmkdvUEJuLMuajCV",
    public_keys: [
      "03b84384cd966c8554ddc2303101fd416f5b4f260161c788d6c62d6c6d293b4880",
      "0336e728be1b9370565204b5de4050d418704cc9c5c2db47f13be30173f7f5bd46",
    ],
    redeem_script: "51210336e728be1b9370565204b5de4050d418704cc9c5c2db47f13be30173f7f5bd462103b84384cd966c8554ddc2303101fd416f5b4f260161c788d6c62d6c6d293b488052ae",
  },
}

addresses.each do |idx, addr_details|
  public_keys = addr_details[:public_keys].sort
  multisig_script = BTC::Script.
    multisig(public_keys: public_keys, signatures_required: 1)
  p2sh_script = multisig_script.p2sh_script
  generated_addr = p2sh_script.standard_address.to_s
  if generated_addr == addr_details[:address]
    puts "YES MATCH:"
    puts "We generated the same one for address #{idx}: #{addr_details}"
  else
    puts "NO MATCH:"
    puts " - Generated address from lexicographically ordered keys: #{generated_addr}"
    puts " - Expected address: #{addr_details[:address]}"
  end
end

puts "Done"

Links to coinbin:

• Address 0
• Address 4
• Address 9