Found another ckparity flaw! Only detected now due to the reworked tag
encoding, but it's just luck this wasn't detected earlier.
Consider the following bit flip:
03 04 80 04 80 04 6b ... data w512 512
43 04 80 04 80 04 6b ... altble 0x304 w512 -512
^
flip
Not only are leb128s problem for ckparity, but even the difference in
alt vs normal tag encoding presents a vulnerability.
So limiting the ckparity tests further, to just 47 of the first 48 bits.
Christopher Haster
879a55add9