PSBT Taproot Input Validation Issue

[timechainz]

Hello again,

I have updated to 6.1.2 and am now seeing some new input validation errors on known valid inputs. I have included an example which was signed in bitcoin-cli

bitcoin-cli walletprocesspsbt "{unsigned}" true "SINGLE|ANYONECANPAY" false false

which results in the following signed psbt:

{
  "tx": {
    "txid": "4810ff15141bd2d7fca4dc4e8fc2f361c716d721f2e221889a2639459d180fc4",
    "hash": "4810ff15141bd2d7fca4dc4e8fc2f361c716d721f2e221889a2639459d180fc4",
    "version": 2,
    "size": 94,
    "vsize": 94,
    "weight": 376,
    "locktime": 0,
    "vin": [
      {
        "txid": "59edb28a4c0c6a9fb319ae6f4e8d5f979b44e786fa127ad012d1eeda83cd944e",
        "vout": 0,
        "scriptSig": {
          "asm": "",
          "hex": ""
        },
        "sequence": 4294967295
      }
    ],
    "vout": [
      {
        "value": 9.90000000,
        "n": 0,
        "scriptPubKey": {
          "asm": "1 2252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6",
          "desc": "rawtr(2252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6)#tfj37s9y",
          "hex": "51202252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6",
          "address": "bc1pyffrxlgln72gtxz0y7cqlkl76n0nsghxm8lm4g82s8jkp0806knqclmd55",
          "type": "witness_v1_taproot"
        }
      }
    ]
  },
  "global_xpubs": [
  ],
  "psbt_version": 0,
  "proprietary": [
  ],
  "unknown": {
  },
  "inputs": [
    {
      "witness_utxo": {
        "amount": 0.00010000,
        "scriptPubKey": {
          "asm": "1 2252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6",
          "desc": "rawtr(2252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6)#tfj37s9y",
          "hex": "51202252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6",
          "address": "bc1pyffrxlgln72gtxz0y7cqlkl76n0nsghxm8lm4g82s8jkp0806knqclmd55",
          "type": "witness_v1_taproot"
        }
      },
      "non_witness_utxo": {
        "txid": "59edb28a4c0c6a9fb319ae6f4e8d5f979b44e786fa127ad012d1eeda83cd944e",
        "hash": "59edb28a4c0c6a9fb319ae6f4e8d5f979b44e786fa127ad012d1eeda83cd944e",
        "version": 1,
        "size": 94,
        "vsize": 94,
        "weight": 376,
        "locktime": 0,
        "vin": [
          {
            "txid": "5d54d7f8e1c17bcf29e5765ab0f40af873a55313c50245ec7eba41427c9afff1",
            "vout": 0,
            "scriptSig": {
              "asm": "",
              "hex": ""
            },
            "sequence": 4294967293
          }
        ],
        "vout": [
          {
            "value": 0.00010000,
            "n": 0,
            "scriptPubKey": {
              "asm": "1 2252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6",
              "desc": "rawtr(2252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6)#tfj37s9y",
              "hex": "51202252337d1f9f9485984f27b00fdbfed4df3822e6d9ffbaa0ea81e560bcefd5a6",
              "address": "bc1pyffrxlgln72gtxz0y7cqlkl76n0nsghxm8lm4g82s8jkp0806knqclmd55",
              "type": "witness_v1_taproot"
            }
          }
        ]
      },
      "sighash": "SINGLE|ANYONECANPAY",
      "taproot_key_path_sig": "643034e6a8dd130e0563ee010f48a61ed0ce4e3b32fae84c76c9478f4cc4a26643a85f8596b9c1556b74a61e6b9056fe5a2a6bb6a5da961864c946bdd4b4eb0383",
      "taproot_internal_key": "8ee617c48a7238c553604be5df980389d0a6fef508099cae34d64a68fcfd7710"
    }
  ],
  "outputs": [
    {
      "taproot_internal_key": "8ee617c48a7238c553604be5df980389d0a6fef508099cae34d64a68fcfd7710"
    }
  ],
  "fee": -9.89990000
}

Sparrow Wallet also confirms this is a valid signature. However, bitcoinjs-lib appears to fail in the validator. I have created a test case which demonstrates this.

https://github.com/timechainz/bitcoinjs-lib-psbt-validation/blob/db3d3bd20f57a89f58f59fa78d641001c6f50fcc/validate-taproot-input.js#LL33C1-L33C1

Any ideas would be appreciated. Thanks!

[junderw]

Thank you for the new example of a valid signature in the PSBT.

The fix was larger than anticipated, so validating signatures is going to be broken until I can straighten things out.

See the PR for details.

[timechainz]

Thanks for the update @junderw! I really appreciate all you do for the project!

[junderw]

Published as 6.1.3