What’s wrong with my script?

There are some issues with the provided BASH scripts for creating and signing Bitcoin transactions using Bitcoin-Cli.

Here is a detailed breakdown of the issue and proposed fixes:

Private key format:

Problem: private_key_1 and private_key_2 are provided as 64 characters hexadecimal strings. However, Bitcoin-Cli expects a private key in wallet import format (WIF) that usually starts with k, l, or 5 and is base58 encoded. Fix: Converts hexadecimal private keys to WIF format. You can use tools like Bitcoin Tools and Online Converters, but make sure they are operating in a safe environment to protect your keys.

Example of conversion using Bitcoin-Cli:

# Convert HEX to WIF for PRIVATE_KEY_1
WIF_PRIVATE_KEY_1=$(bitcoin-cli -regtest dumpprivkey )

# Convert HEX to WIF for PRIVATE_KEY_2
WIF_PRIVATE_KEY_2=$(bitcoin-cli -regtest dumpprivkey )

Replace and The actual Bitcoin address is linked to the private key.

Invalid input_txid:

Problem: input_txid is set to all zeros (0000 … 0000), but this is not a valid transaction ID. This causes CREATERAWTRANSACTION A command that fails because it refers to a transaction that does not exist.

Fix: Use a valid transaction ID from the blockchain (especially because it works with RegTest, make sure the transaction exists).

example:

INPUT_TXID="your_valid_txid_here"

ScriptPubkey Format:

problem: Redeem_script_hex It appears to be for Multisig setup, but I’ll make sure it matches the actual script in UTXO that I’m trying to use.

Fix: Check it Redeem_script_hex Correctly supports UTXO lock scripts. For standard P2SH or P2WSH scripts, make sure the format matches the expected pattern.

Deleted SignRawTransactionWithKey command:

Problem: Depending on the Bitcoin-Cli version, sightrawtransactionwithkey Commands may be deprecated.

Fix: Used sightrawtransactionwithkey If supported. Otherwise, consider using it sightrawtransaction withwallet Alternatively, update the script according to the latest Bitcoin-Cli documentation.

Output address verification:

problem: output_address It starts with 3not a standard prefix for RegTest. In RegTest, addresses usually start with different characters.

RegTest prefix:

Legacy addresses start with: m or n
The P2SH address starts with: 2
BECH32 addresses start with: BCRT1

address 325UUECEQUYRTD28XS2HVAXDAJHM7XZQVF
It does not conform to the standard RegTest address format.

Fix: Check output_address Valid address for the RegTest environment. You can generate a new address using:

# Generate a new legacy address in regtest
bitcoin-cli -regtest getnewaddress "" legacy

# Generate a new P2SH address in regtest
bitcoin-cli -regtest getnewaddress "" p2sh

# Generate a new bech32 address in regtest
bitcoin-cli -regtest getnewaddress "" bech32

Exchange addresses 325UUECEQUYRTD28XS2HVAXDAJHM7XZQVF Use the above command to use the address generated directly from the RegTest Bitcoin node.

Dependencies and Tools:

Problem: The script uses JQ to parse the JSON. Make sure JQ is installed on your system.

Fix: Install JQ if it doesn’t already exist.

# sudo apt-get install jq

Using sequence numbers:

problem: order It is set to 0xffffffff. This is the default and may not be necessary unless you implement certain features such as per-swap (RBF).

Modify: If not required, you can omit the sequence field in the input object.

Overall script enhancements:

Security: Avoid hardcoded private keys in scripts. Consider using environment variables or a major safe management system.

Error Handling: Add a check to ensure that each command runs successfully before proceeding to the next step. This helps you debug the problem more effectively.

example:

# Create raw transaction
UNSIGNED_TX=$(bitcoin-cli -regtest -rpcuser=alice -rpcpassword=password createrawtransaction '({"txid":"'$INPUT_TXID'","vout":'$INPUT_VOUT'})' '{"'$OUTPUT_ADDRESS'":'$VALUE'}')
if ( $? -ne 0 ); then
  echo "Failed to create raw transaction."
  exit 1
fi

# Sign transaction
SIGNED_TX=$(bitcoin-cli -regtest -rpcuser=alice -rpcpassword=password signrawtransactionwithkey "$UNSIGNED_TX" '("'$WIF_PRIVATE_KEY_1'", "'$WIF_PRIVATE_KEY_2'")' '({"txid":"'$INPUT_TXID'","vout":'$INPUT_VOUT',"scriptPubKey":"'$REDEEM_SCRIPT_HEX'","redeemScript":"'$REDEEM_SCRIPT_HEX'"})')
if ( $? -ne 0 ); then
  echo "Failed to sign transaction."
  exit 1
fi

By addressing these issues, the script must function correctly when creating and signing Bitcoin transactions within the RegTest environment.