if the card is removed during APDU send the response returned is nil. In places like the Pair function (could be other places too) the response Sw code is checked before checking if err is nil. In this case the program crashes because resp is nil

Please remove the line

apdu commands and responses are always logged.

options:

• remove logger
• add SetLogLevel so that by default nothing is logged
• add a SetLogger func so that the real logger is managed outside this pkg

Would you be open to a PR that updates the version of go-ethereum used as a dependency in this project? It would be helpful in resolving build issues with btcd versioning. The specific problem is documented here: btcsuite/btcd#1839

Context:

In ParseSignature, the r-component of the DER signature is length-checked and updated if the length is 33 bytes (here). The purpose appears to be for recovering the v parameter, which requires 32-byte r and s fields

Bug:

The s-component can also be 33 bytes and should have the same check.