steem-verifier helps you debug signatures on Steem transactions.
You can use pip to install this tool:
pip install steem-verifier
Really simple, after installing, you can call the command line tool passing a transaction id as parameter:
steem-verifier 6a3e9a99cf3bc9464c6aa26c7daf63454de8d411
This will query the Steem blockchain for the transaction and verify it's signature(s). An example result is shown bellow:
=> Retrieving transaction...
=> Extracting public keys...
=> Extracted public keys are:
STM5vgGoHBrUuDCspAPYi3dLwSyistyrz61NWkZNUAXAifZJaDLPF
=> The accounts who signed the transaction (public key owners) are:
blocktrades