1. A computer implemented method for executing a message digest instruction in a processor, the message digest instruction comprising a query function, the method comprising: determining from a previously defined function code a message digest operation to be executed, the previously defined function code defining any one of a compute message digest operation or a function query operation; responsive to the determined message digest operation to be executed being a compute message digest operation, performing the compute message digest operation on an operand, the compute message digest operation comprising performing a SHA-1 (Secure Hash Algorithm) hashing algorithm; and responsive to the determined message digest operation to be executed being a function query operation, saving status word bits in a parameter block, the status word bits corresponding to one or more function codes installed on the processor.