0

I have two addresses in my regtest.

A address is the P2SH-P2PKH. (sender)

B address is the P2SH-P2PKH, but with OP_CHECKLOCKTIMEVERIFY block height 201. (receiver)

My regtest doesen't have any block before it, Then I create some blocks (101) for A and transfer some bitcoins to B. A Wants that the UTXO is available after block with height 201 for that reason B creates this kind of script

$ bitcoin-cli decodescript 04C9000000B17576a914697c78eb51aadd3d977c1407e99baf9fe772240588AC
{
  "asm": "201 OP_CHECKLOCKTIMEVERIFY OP_DROP OP_DUP OP_HASH160 697c78eb51aadd3d977c1407e99baf9fe7722405 OP_EQUALVERIFY OP_CHECKSIG",
  "type": "nonstandard",
  "p2sh": "2N9X4FL8mg9Tc88FuHgPzBqFXa6U1etuUck",
  "segwit": {
    "asm": "0 30ff9dbf6bab02945016f39e95aa5d67e0f2e6adc7392d1066a1e171513bcb33",
    "hex": "002030ff9dbf6bab02945016f39e95aa5d67e0f2e6adc7392d1066a1e171513bcb33",
    "reqSigs": 1,
    "type": "witness_v0_scripthash",
    "addresses": [
      "bcrt1qxrlem0mt4vpfg5qk7w0ft2javls09e4dcuuj6yrx58shz5fmeves2tkaxf"
    ],
    "p2sh-segwit": "2MtXn1EgzySHEw8BQXLG8n58dxss6NGRsGU"
  }
}

B wants spend his bitcoins, it's the UTXO

[
  {
    "txid": "8cfc83e28fa520fed13a4199b72f588bf95fa84679d44b94efdff5d1f9f7812f",
    "vout": 0,
    "address": "2N9X4FL8mg9Tc88FuHgPzBqFXa6U1etuUck",
    "label": "",
    "scriptPubKey": "a914b2808972cf93673354475ece46820a2b3060978487",
    "amount": 49.99100000,
    "confirmations": 600,
    "spendable": false,
    "solvable": false,
    "safe": true
  }
]

And the current tip

$ bitcoin-cli getchaintips
[
  {
    "height": 701,
    "hash": "1967a98ea0cca367a3699d09a30d046d31ed711989bc6f1a2ae61d7ade910866",
    "branchlen": 0,
    "status": "active"
  }
]

Then B creates the transaction like this

02000000012f81f7f9d1f5dfef944bd47946a85ff98b582fb799413ad1fe20a58fe283fc8c000000008B47304402204cdc56d5be942d05edc218e40de872c9f50e78e018bbbbc9c11a05590aa54e8d02204163ce5796789fe4a7c9d1b1f0b3145ccca1eabb9489b92a4c6bc05508d5cbe6012102839f6ea8422639336f208a2cd2c199872f3e628bff39545eda72d8f71d4b45e42004C9000000B17576a914697c78eb51aadd3d977c1407e99baf9fe772240588ACfeffffff01c07aea290100000017a914d872ea0250c832eca1d7a75434db807397670ccd87C9000000

and uses C9000000 in Locktime field

{
  "txid": "d45d54d3cdae6c22f44cacfd705b2c1234658759f390d387186794240a77b16c",
  "hash": "d45d54d3cdae6c22f44cacfd705b2c1234658759f390d387186794240a77b16c",
  "version": 2,
  "size": 222,
  "vsize": 222,
  "weight": 888,
  "locktime": 201,
  "vin": [
    {
      "txid": "8cfc83e28fa520fed13a4199b72f588bf95fa84679d44b94efdff5d1f9f7812f",
      "vout": 0,
      "scriptSig": {
        "asm": "304402204cdc56d5be942d05edc218e40de872c9f50e78e018bbbbc9c11a05590aa54e8d02204163ce5796789fe4a7c9d1b1f0b3145ccca1eabb9489b92a4c6bc05508d5cbe6[ALL] 02839f6ea8422639336f208a2cd2c199872f3e628bff39545eda72d8f71d4b45e4 04c9000000b17576a914697c78eb51aadd3d977c1407e99baf9fe772240588ac",
        "hex": "47304402204cdc56d5be942d05edc218e40de872c9f50e78e018bbbbc9c11a05590aa54e8d02204163ce5796789fe4a7c9d1b1f0b3145ccca1eabb9489b92a4c6bc05508d5cbe6012102839f6ea8422639336f208a2cd2c199872f3e628bff39545eda72d8f71d4b45e42004c9000000b17576a914697c78eb51aadd3d977c1407e99baf9fe772240588ac"
      },
      "sequence": 4294967294
    }
  ],
  "vout": [
    {
      "value": 49.982,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_HASH160 d872ea0250c832eca1d7a75434db807397670ccd OP_EQUAL",
        "hex": "a914d872ea0250c832eca1d7a75434db807397670ccd87",
        "reqSigs": 1,
        "type": "scripthash",
        "addresses": [
          "2NCyhc6DkujYJE6ui1sVFCJAiSa79BDWqKv"
        ]
      }
    }
  ]
}

But When I try to send Transaction I get that error:

non-mandatory-script-verify-flag (unknown error) (code 64)

With help of btcdeb I can see that error "error: exception thrown: non-minimally encoded script. number". The same logic BUT with date works.

One more question: Is it correct flow? B(receiver) creates P2SH with 201 OP_CHECKLOCKTIMEVERIFY OP_DROP in order to satisfy A (sender) requirements?

1 Answer 1

3

The problem is with your script. If you want to push 201, you should use 02C900 rather than 04C9000000. The argument to OP_CHECKLOCKTIMEVERIFY is a number, not a byte array, so you must use the shortest encoding possible for it.

9
  • Thanks again for your time. the scenario is correct? I Mean, B(receiver) creates P2SH with 201 OP_CHECKLOCKTIMEVERIFY OP_DROP in order to satisfy A (sender) requirements?
    – monkeyUser
    Commented May 8, 2020 at 8:46
  • 1
    The top bit is a sign bit, so C9 would be interpreted as the number -73. Commented May 20, 2020 at 15:51
  • 1
    Because 0x66 has top bit 0, so it's interpreted as a positive number. Commented May 22, 2020 at 20:30
  • 1
    I don't know what that means. The number is of course already in binary in the script. Bytes in a computer contain bits... Commented May 22, 2020 at 21:52
  • 1
    Ah, I see. Now, when stack elements are interpreted as numbers, they use a sign and magnitude representation, not two's complement. Commented May 22, 2020 at 22:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.