Taproot Sighash ans Schnorr

I have done all possible checks: signhash and taproot calculation, no changes in BASE64 processes, empty symbols, Shnorr validity and that BASE64 is exactly 64 (not 64 + 1), but I get the same error every time.

Logic: 1. Receive psbt and decode -> Sign inputs (I don't finalise, the server does) using Default method (ALL the same result)-> encode in Base64 -> return partially signed PSBT to server.

I get the "Invalid Schnorr" error every time by server. You see, if you compare script PSBT and output psbt, they are 99% identical except for Shnorr (field unknown 13). I've attached a screenshot to show the difference.

  1. I thought the problem might be in the formats for the server, but also Bitcoin cli analyse returns an ‘updater’ status for my script output:
{
    { ‘result’: {
        { ‘inputs’: [
            {
                ‘has_utxo": true,
                ‘is_final": false,
                { ‘next’: { ‘updater’.
            },
            {
                ‘has_utxo": true,
                ‘is_final": false,
                { ‘next’: { ‘updater’.
            }
        ],
        ‘estimated_vsize": 286,
        ‘estimated_feerate": 6.0e-5,
        ‘fee": 1.716e-5,
        ‘next": { ‘updater’.
    },
    ‘error": null,
    ‘id": null
}
  1. Although if I sign via Unisat or any other extension wallet - it will return:
{
    ‘result": {
        { ‘inputs’: [
            {
                ‘has_utxo": true,
                ‘is_final": false,
                { ‘next’: { ‘updater’.
            },
            {
                ‘has_utxo": true,
                ‘is_final": false,
                { ‘next’: ‘finalizer’.
            }
        ],
        ‘fee": 1.716e-5,
        ‘next": { ‘updater’
    },
    ‘error": null,
    ‘id": null
}

Code:

func main() {
    wifKeyStr := "WIF"
    psbtBase64 := "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"
    cleanPSBTBase64 := cleanBase64(psbtBase64)

    psbtBytes, _ := base64.StdEncoding.DecodeString(cleanPSBTBase64)
    packet, _ := psbt.NewFromRawBytes(bytes.NewReader(psbtBytes), false)

    prevOutFetcher := txscript.NewMultiPrevOutFetcher(nil)
    for i, input := range packet.Inputs {
        if input.WitnessUtxo != nil {
            prevOutFetcher.AddPrevOut(packet.UnsignedTx.TxIn[i].PreviousOutPoint, &wire.TxOut{
                Value:    input.WitnessUtxo.Value,
                PkScript: input.WitnessUtxo.PkScript,
            })
        }
    }

    inputToSign := 1
    if len(packet.Inputs[inputToSign].TaprootInternalKey) > 0 {
        sigHashes := txscript.NewTxSigHashes(packet.UnsignedTx, prevOutFetcher)
        pkScript, _ := getInputScript(packet, inputToSign)
        amount, _ := getInputAmount(packet, inputToSign)

        taprootInternalKey := packet.Inputs[inputToSign].TaprootInternalKey
        wifKey, _ := btcutil.DecodeWIF(wifKeyStr)
        publicKeyFromWIF := schnorr.SerializePubKey(wifKey.PrivKey.PubKey())

        if bytes.Equal(taprootInternalKey, publicKeyFromWIF) {
            sighashType := txscript.SigHashDefault
            sighash, _ := txscript.CalcTaprootSignatureHash(sigHashes, sighashType, packet.UnsignedTx, inputToSign, txscript.NewCannedPrevOutputFetcher(pkScript, amount))

            signature, _ := schnorr.Sign(wifKey.PrivKey, sighash)
            serializedSig := signature.Serialize()

            packet.Inputs[inputToSign].TaprootKeySpendSig = serializedSig
        }
    }

    signedPsbtBase64, _ := packet.B64Encode()
    fmt.Printf("Signed PSBT (Base64): %s\n", signedPsbtBase64)
}

func cleanBase64(s string) string {
    return strings.Join(strings.Fields(s), "")
}

func getInputScript(packet *psbt.Packet, idx int) ([]byte, error) {
    input := packet.Inputs[idx]
    if input.WitnessUtxo != nil && len(input.WitnessUtxo.PkScript) > 0 {
        return input.WitnessUtxo.PkScript, nil
    }
    if input.NonWitnessUtxo != nil {
        prevTx := input.NonWitnessUtxo
        outPoint := packet.UnsignedTx.TxIn[idx].PreviousOutPoint
        if int(outPoint.Index) >= len(prevTx.TxOut) {
            return nil, fmt.Errorf("Invalid outpoint index %d for input %d", outPoint.Index, idx)
        }
        return prevTx.TxOut[outPoint.Index].PkScript, nil
    }
    return nil, fmt.Errorf("PkScript not found for input %d", idx)
}

func getInputAmount(packet *psbt.Packet, idx int) (int64, error) {
    input := packet.Inputs[idx]
    if input.WitnessUtxo != nil {
        return input.WitnessUtxo.Value, nil
    }
    if input.NonWitnessUtxo != nil {
        prevTx := input.NonWitnessUtxo
        outPoint := packet.UnsignedTx.TxIn[idx].PreviousOutPoint
        if int(outPoint.Index) >= len(prevTx.TxOut) {
            return 0, fmt.Errorf("Invalid outpoint index %d for input %d", outPoint.Index, idx)
        }
        return prevTx.TxOut[outPoint.Index].Value, nil
    }
    return 0, fmt.Errorf("WitnessUtxo or NonWitnessUtxo not found for input %d", idx)
}

OUTPUT:

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
Calculating Taproot address...
Taproot Address: bc1p38pg0767rhujdn569lug887yea73rn7vpwz546y7czzcptql9caq6cafwt
TapKeyBytes: 89c287fb5e1df926ce9a2ff8839fc4cf7d11cfcc0b854ae89ec08580ac1f2e3a
2024/11/27 12:13:42 Taproot Address: bc1p38pg0767rhujdn569lug887yea73rn7vpwz546y7czzcptql9caq6cafwt
Public Key (Hex): ad17b47056ee8c7257aefb92fcc82f9ea4691c748b90000e3df2ba6471403d7b
Decoding PSBT...
PSBT successfully decoded.
Parsing PSBT...
PSBT successfully parsed.
Creating MultiPrevOutFetcher...
Adding previous output for input 0
Adding previous output for input 1
MultiPrevOutFetcher successfully created.
Signing input 1...
Input uses Taproot.
Creating TxSigHashes...
TxSigHashes successfully created.
PkScript: 512089c287fb5e1df926ce9a2ff8839fc4cf7d11cfcc0b854ae89ec08580ac1f2e3a
Amount: 55470
TaprootInternalKey of input 1: ad17b47056ee8c7257aefb92fcc82f9ea4691c748b90000e3df2ba6471403d7b
Public key from WIF: ad17b47056ee8c7257aefb92fcc82f9ea4691c748b90000e3df2ba6471403d7b
The signing key matches the TaprootInternalKey of the input.
Calculating sighash...
Sighash: 92aec029f002090d7621fffce4ebac7ff333d971e832db3980bb93112cb851ce
Creating signature...
Signature: 98dcfc29a85bc89ed35a86fa8073d5708ea93e095f4171b65c72ed12227d537a849b539ef6f9b845aeef61ff0bd4e94b664981e14a29e2443ddca98ecb9360f3
Signature for input 1 added.
Serializing signed PSBT...
Signed PSBT (Base64): cHNidP8BAPwCAAAAAgupxw+/SJhtowTzcr1wx9c/uanFKaJ3yU3J6UKjMTMzlAEAAAD/////Q9g6nnkQbdroR/sr2jeNqZ9nlZbVuqSNdjakxTxLgYADAAAAAP////8ETQEAAAAAAAAiUSCJwof7Xh35Js6aL/iDn8TPfRHPzAuFSuiewIWArB8uOmGDAAAAAAAAIlEgsxHYe7mlcSxOwOnapg4WHRT5UuB+vWF8uMz6Oxu5Bf9DAgAAAAAAABYAFAnkWBtaeW/v/BxPBmkgboAct6nrVkwAAAAAAAAiUSCJwof7Xh35Js6aL/iDn8TPfRHPzAuFSuiewIWArB8uOgAAAAAI/AJtZQNzaWdAvHgNmehOZ6jBZiu5ckCncLnVeViAr3PlKIgR2v8NPzhW/OXpu8oaK4b3bgRIL/qrMT5WlpgdybZGXVaAxSJVIwv8Am1lBnNpZ2V4cAhCeTbOW+ZAAAABAStNAQAAAAAAACJRIDCs9kAJfdTiQei7Cf+RSH3Cwr5oxFjNj27APixQD2L4ARcgc+G1jBTUGzdWX447VOZ6zEec2eeffMqg8KTrQ6plriIAAQErrtgAAAAAAAAiUSCJwof7Xh35Js6aL/iDn8TPfRHPzAuFSuiewIWArB8uOgETQJjc/CmoW8ie01qG+oBz1XCOqT4JX0Fxtlxy7RIifVN6hJtTnvb5uEWu72H/C9TpS2ZJgeFKKeJEPdypjsuTYPMBFyCtF7RwVu6Mcleu+5L8yC+epGkcdIuQAA498rpkcUA9ewAAAAAA

PSBT MY Script output:

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

Wallet extension PSBT:

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

Raw PSBT (input psbt fot scirpt and extension):

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

The big problem is that I don't understand why sighash is incorrect (and hence Schnorr's signature), but I don't think the problem is the formation of the schnorr signature. I think I'm considering something wrong to calculate the sighash OR not considering, although I can't figure out what exactly, since I don't get errors at any stage in my code other than checking the BTC CLI or POST to the server



from Recent Questions - Bitcoin Stack Exchange https://ift.tt/kD75lKi
via IFTTT

Popular posts from this blog

Do Kwon’s Detention Prolonged Until 2024 As Montenegro Responds To Extradition Requests

Image
According to an International Business Times report , Montenegro’s Supreme Court decided to extend the detention of TerraForm Labs founder and CEO Do Kwon until February 2024, following extradition requests from the United States and South Korea. Closed-Door Discussions Reveal Montenegro’s Plan For Do Kwon Initially set to be extradited to the US on December 15, Do Kwon’s fate turned when the Montenegrin High Court ruled to prolong his stay until February 15, 2024. The decision stems from charges related to the collapse of the TerraUSD stablecoin, which led to significant financial losses. The High Court had previously ordered Kwon’s extradition by Friday, but his defense team appealed the decision in the appellate court in Podgorica, the capital of Montenegro. The Montenegrin Court of Appeal confirmed that Kwon contested the High Court’s ruling, vehemently stating, “I do not submit to the court’s decision.” Recent reports indicate that Montenegro’s Justice Minister, Andrej Mil...
Read more

Sam Bankman-Fried Trial Begins Tomorrow: 3 Reasons Ex-SEC Official Foresees Conviction

Image
The trial of Sam Bankman-Fried, the founder of cryptocurrency exchange FTX and hedge fund Alameda Research, is set to commence in New York on Tuesday, October 3.  This comes almost a year after the collapse of both FTX and Alameda Research. The events leading up to the trial paint a picture of alleged fraudulent activities and money laundering that caused significant damage to the businesses involved. Ex-SEC Official’s Bleak Prediction As Sam Bankman-Fried Trial Commences In a nutshell, Alameda Research purportedly took customer deposits from FTX and invested them in fictitious crypto tokens, which derived their value from the confidence in FTX’s operations.  When this confidence waned, FTX and Alameda Research suffered substantial losses, which many argue contributed to a broader disillusionment in the cryptocurrency industry.  Following an investigation, federal authorities uncovered numerous alleged crimes, leading to seven federal fraud and money-laundering cha...
Read more

April’s Crypto Game-Changers: 7 Events Set To Drastically Impact The Course Of Digital Currencies

Image
As the crypto market ended March positively, the industry gears up for an eventful April, marked by crucial developments and milestones that could significantly impact the digital asset landscape.  Crypto Halvings And Regulatory Deadlines The month starts with the Bitcoin Cash (BCH) halving event scheduled for April 2nd. Similar to Bitcoin (BTC), BCH undergoes a halving approximately every four years, which reduces mining profits for BCH miners.  On April 10, the US is scheduled to announce March’s Consumer Price Index (CPI), a vital indicator that measures the average price change paid by urban consumers for a basket of goods and services.  The Federal Reserve closely monitors the CPI as it influences inflation and, consequently, the central bank’s decisions regarding interest rates. Any changes in interest rates can ripple effect on the overall crypto market performance. April 19 marks the deadline for the US Securities and Exchange Commission (SEC) and US crypto...
Read more