:= bigmod.NewNat().SetBytes(b, c.N); err == nil && k.IsZero() == 0 { p, err := c.newPoint().ScalarBaseMult(k.Bytes(c.N)) return k, p, err } if testingOnlyRejection != nil { testingOnlyRejection() } } } // testingOnlyRejection is called when rejection sampling in // randomPoint rejects a candidate for being higher than the modulus. var testingOnlyRejection func() // Signature is an ECDSA signature, where r and s are represented as big-endian // byte slices of the same length as the curve order. type...