Bitcoin Signer Error: Witness Hash Mismatch
As a Bitcoin developer, you’ve probably encountered issues when trying to sign transactions using private keys on your local machine. A common error that can occur is the “Witness Hash Mismatch” issue, which prevents the script from validating and signing transactions correctly.
In this article, we’ll delve into the details of the issue and provide a step-by-step guide on how to fix it.
Problem
When trying to sign a raw transaction with your private key on Bitcoin Core (BTC-Testnet) using Regtest, you may encounter the following error:
Verifying witness hash mismatch
This error usually occurs when the script is unable to verify that the witness hash matches the expected value in the transaction. This can be caused by various factors, such as:
- Incorrect or missing script hashes
- Improper private key configuration
- Invalid or corrupt transactions
- Script errors or syntax issues
Troubleshooting steps
To troubleshoot this issue and resolve the Witness hash mismatch error, follow these steps:
1. Check your private key configuration
Make sure your private key is configured correctly in Bitcoin Core. Here are a few things to check:
- Make sure you have installed the
bitcoin-qtpackage and verified its installation.
- Verify that the private key file (usually located at
$HOME/.Bitcoin/privkey.json) contains valid script hashes for all scripts, including the transaction you are trying to sign.
2. Inspect transaction details
Gather more information about the transaction you are trying to sign:
- Transaction details
: Verify that the transaction hash is correct and matches the expected value.
- Debug scripts: Run the script with the
--debugflag to get detailed output, which can help identify any issues.
Example command:
bitcoin-qt --regtest -txindex --debug -o myscript tx
3. Verify Witness hashes
Verify that the witness hashes for all scripts in your script are correct:
- Get script hashes: Run
bitcoin-qt --list-scriptsto list all scripts with the correct hash.
- Verify script hashes
: Check that each script’s hash matches the expected value.
Example command:
bitcoin-qt --regtest -txindex --debug -o myscript tx
4. Run the script with debug output
Run the script using the --debug flag to generate detailed debug output:
* bitcoin-qt –regtest -txindex –debug -o myscript tx
This will display a detailed list of transactions, including hashes and scripts used.
5. Update Script (Optional)
If you suspect that the script itself is incorrect or outdated, update the script to ensure that it matches the latest available version:
- Update the script: Rungit pull` or use a package manager like pip to update your script to the latest version.
Example:
git clone
cd scripthash
git checkout
6. Rerun the script with corrected script hashes
Once you have corrected any issues with the script hashes, run the script again to verify that it produces the correct transaction output.
Conclusion
In this article, we have gone through the steps to resolve the “Witness program hash mismatch” error in Bitcoin Core when signing transactions using private keys. By checking your private key configuration, inspecting transaction details, checking witness hashes, running scripts with debug results, updating scripts (if necessary), and re-running scripts with correct script hashes, you should be able to overcome this issue and successfully sign raw transactions using Regtest.
