WSTS threshold-raise via oversized polynomial

WSTS (Weighted Schnorr Threshold Signatures), aka WileyProofs, is based on FROST and was vulnerable to threshold-raise attacks. Before PR #88, the per-signer DKG verification in src/v1.rs only checked the Schnorr ID, not the commitment-vector length (source):

1// src/v1.rs — Trust-Machines/wsts (vulnerable, before PR #88)
2if !comm.verify() {
3    bad_ids.push(*i);
4}
5self.group_key += comm.poly[0];

A malicious signer could append commitments to its poly to silently raise the reconstruction threshold. The Trail of Bits length-check fix in Trust-Machines/wsts landed as PR #88 (“Check length of polynomials”). PR #88 added the explicit equality check at every DKG verification site (source):

1// src/v1.rs — Trust-Machines/wsts (fixed, PR #88)
2if comm.poly.len() != threshold || !comm.verify() {
3    bad_ids.push(*i);
4} else {
5    self.group_key += comm.poly[0];
6}