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bitcoin core – I am unable to parse the UTXO from the chainstate


I’ve an issue with studying tx out from the Bitcoin Core LevelDB chainstate storage. I do know that the construction of the present model of the chainstate is key => worth the place the hot button is a prefix (0x43) | tx_id | coin_n (https://github.com/bitcoin/bitcoin/blob/0d509bab45d292caeaf34600e57b5928757c6005/src/txdb.cpp#L39) and the worth is obfuscated by the obfuscation key by way of the Coin XOR obfuscation_key worth of the Coin.

Ref: https://github.com/bitcoin/bitcoin/blob/0d509bab45d292caeaf34600e57b5928757c6005/src/txdb.cpp#L68

So, i’ve efficiently learn the prefix, obfuscation key and the txId with the output_n

key:
    prefix: [1]byte

(COutPoint)
    txID: [32]byte
    outN: VARINT

Ref: https://github.com/bitcoin/bitcoin/blob/0d509bab45d292caeaf34600e57b5928757c6005/src/primitives/transaction.h#L28

The Coin construction (https://github.com/bitcoin/bitcoin/blob/0d509bab45d292caeaf34600e57b5928757c6005/src/cash.h#L24)

code: VARINT((coinbase ? 1 : 0) | (top << 1))
txOut:  CTxOut (through TxOutCompression)

Now i stucked on the studying the code. In some values, i’ve a sound code with true block top and coinbase boolean. However in some values i’ve invalid information the place the block top will not be the identical with the transaction’s block top.

How one can reproduce this to assist me?

My enter (LevelDB view):

Key                                                                     | Worth
0e006f62667573636174655f6b6579                                          | 08f05564aa8317fe24
42                                                                      | bde0dff15a88e0eb3d71c37fd986c4cdfd8916bd0b8d0b13343afef66829284d
4300c4626bf6dc028730d3a1f3951d398a71a164d8a898965d11bb8a699091144c00    | 8f6778aa979ddbbc669c187cbf11ad2e30ca53025f3f3b961e
43047ae5966a25bdc32ab4a258c57e28ffa763fc273c08b38fe85839e99e71402500    | ef6778aa979ddbbc669c187cbf11ad2e30ca53025f3f3b961e
430e3afb85bb66cc8a5edfd96f4aad1e65e4e6cf38f1dcc584c525d0b25b89599c00    | 706e56b68303740168c3add6552bf877fa95fb9d2bcbd6e142bb

When i’m studying the primary values and deobfuscate them, i get true block top and coinbase. However when i’m studying the final worth, i get this:

~ 706e56b68303740168c3add6552bf877fa95fb9d2bcbd6e142bb XOR f05564aa8317fe24
~ 803b321c00148a259896c97cd63c06530ac09f37a8dc28c5b2ee

So, when i’m attempting to learn the uvarint from this, i get an invalid code with invalid block top:

bundle major

import (
    "bytes"
    "encoding/binary"
    "encoding/hex"
    "log"
)

func major() 1 == 1
    log.Println("isCoinbase", isCoinbase)

Outcome

2024/04/03 15:24:06 code 7552
2024/04/03 15:24:06 blockHeight 3776
2024/04/03 15:24:06 isCoinbase false

Anticipated outcome: blockHeight have to be 93, coinbase false.

Different data. My deobfuscate perform code:

func deobfuscateValue(obfuscationKey, worth []byte) []byte {
    deobfuscatedValue := make([]byte, len(worth))

    copy(deobfuscatedValue, worth)

    for i, c := vary worth {
        deobfuscatedValue[i] = c ^ obfuscationKey[i%len(obfuscationKey)]
    }

    return deobfuscatedValue
}

I’m working the personal regtest community on the Bitcoin Core v0.21 (i’ve tried on the 24 model and have the identical outcomes). I’m use bitcoin-testnet-box docker picture to check my program. Additionally, i’ve examined on the mainnet, however have the identical downside too. My blockchain now have solely 105 blocks.

Thanks for serving to. I believe I missed one thing easy and simply do not know one thing in regards to the chainstate or C++ realization or Golang 🙂

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