dca_bitlen
pbits = dca_bitlen(p, plen);
modbits = dca_bitlen(reqp->dr_ctx.mod, reqp->dr_ctx.modlen);
expbits = dca_bitlen(exp, explen);
qbits = dca_bitlen(q, qlen);
pbits = dca_bitlen(p, plen);
int dca_bitlen(unsigned char *, int);