The patch is now 83 lines affecting 3 files (sigchk sigmak elitmk). I
think the DER version would be a few more, and it took less than 30
minutes. I am using a keyid of zero to trigger the MIC mode (internally I
derive the algorithm from the keyid, but I could a flag or something
Do you have a sense of how big the code would be to implement the MDC in
the encryption layer as originally proposed? Possibly if the MDC were
in a separate packet so you could identify it easily?