some comments and more loops in test

This commit is contained in:
Pieter Wuille 2013-03-10 22:23:33 +01:00
parent 14b195ee65
commit cbd3617ea1
2 changed files with 18 additions and 7 deletions

15
ecdsa.h
View file

@ -28,7 +28,7 @@ private:
public:
Signature(Context &ctx) : r(ctx), s(ctx) {}
bool Verify(Context &ctx, const GroupElemJac &pubkey, const Number &message) {
bool RecomputeR(Context &ctx, Number &r2, const GroupElemJac &pubkey, const Number &message) {
const GroupConstants &c = GetGroupConst();
if (r.IsNeg() || s.IsNeg())
@ -39,7 +39,7 @@ public:
return false;
Context ct(ctx);
Number sn(ct), u1(ct), u2(ct), xrn(ct);
Number sn(ct), u1(ct), u2(ct);
sn.SetModInverse(ct, s, c.order);
// printf("s=%s 1/s=%s\n", s.ToString().c_str(), sn.ToString().c_str());
u1.SetModMul(ct, sn, message, c.order);
@ -50,8 +50,15 @@ public:
return false;
FieldElem xr; pr.GetX(xr);
unsigned char xrb[32]; xr.GetBytes(xrb);
xrn.SetBytes(xrb,32); xrn.SetMod(ct,xrn,c.order);
return xrn.Compare(r) == 0;
r2.SetBytes(xrb,32); r2.SetMod(ct,r2,c.order);
}
bool Verify(Context &ctx, const GroupElemJac &pubkey, const Number &message) {
Context ct(ctx);
Number r2(ct);
if (!RecomputeR(ct, r2, pubkey, message))
return false;
return r2.Compare(r) == 0;
}
void SetRS(const Number &rin, const Number &sin) {

View file

@ -10,18 +10,23 @@ using namespace secp256k1;
void test_ecmult() {
Context ctx;
// random starting point A (on the curve)
FieldElem ax; ax.SetHex("8b30bbe9ae2a990696b22f670709dff3727fd8bc04d3362c6c7bf458e2846004");
FieldElem ay; ay.SetHex("a357ae915c4a65281309edf20504740f0eb3343990216b4f81063cb65f2f7e0f");
GroupElemJac a(ax,ay);
// two random initial factors xn and gn
Number xn(ctx); xn.SetHex("84cc5452f7fde1edb4d38a8ce9b1b84ccef31f146e569be9705d357a42985407");
Number gn(ctx); gn.SetHex("a1e58d22553dcd42b23980625d4c57a96e9323d42b3152e5ca2c3990edc7c9de");
// two small multipliers to be applied to xn and gn in every iteration:
Number xf(ctx); xf.SetHex("1337");
Number gf(ctx); gf.SetHex("7113");
// accumulators with the resulting coefficients to A and G
Number ae(ctx); ae.SetHex("01");
Number ge(ctx); ge.SetHex("00");
// the point being computed
GroupElemJac x = a;
const Number &order = GetGroupConst().order;
for (int i=0; i<1000; i++) {
for (int i=0; i<20000; i++) {
// in each iteration, compute X = xn*X + gn*G;
ECMult(ctx, x, x, xn, gn);
// also compute ae and ge: the actual accumulated factors for A and G
@ -35,11 +40,10 @@ void test_ecmult() {
gn.SetModMul(ctx, gn, gf, order);
}
std::string res = x.ToString();
assert(res == "(D37F97BBF58B4ECA238329D272C9AF0194F062B851EDF9B40F2294FA00BBFCA2,B127748E9A9F347257051588D44A1B822CA731833B2653AA3646C59A8ADAF295)");
assert(res == "(D6E96687F9B10D092A6F35439D86CEBEA4535D0D409F53586440BD74B933E830,B95CBCA2C77DA786539BE8FD53354D2D3B4F566AE658045407ED6015EE1B2A88)");
// redo the computation, but directly with the resulting ae and ge coefficients:
GroupElemJac x2; ECMult(ctx, x2, a, ae, ge);
std::string res2 = x2.ToString();
printf("res=%s res2=%s\n", res.c_str(), res2.c_str());
assert(res == res2);
}