HMAC Hex Key Ambiguity

This happens all the time.. Quite often, a service provider will provide instructions for HMAC generation, and will provide a hexadecimal HMAC key in the example, such as: 01A0251D601FEF3305A38B124068A001CF3F099AA187DB2886314C67CDFDEBCD This is implicitly ambiguous because there are two ways to interpret the instructions: 1) The HMAC key is composed of the …