#include "seal.h" unsigned long mkcsum (csum, start, limit) register unsigned long csum; char *start, *limit; { register int c; while (start < limit) { c = (unsigned char) *start++; if (csum & 1) csum = (csum >> 1) | CSHIBIT; else csum >>= 1; csum += c; csum &= CSMASK; } return csum; }