9#include <botan/ecgdsa.h>
10#include <botan/keypair.h>
11#include <botan/reducer.h>
12#include <botan/internal/pk_ops_impl.h>
13#include <botan/internal/point_mul.h>
39 const std::string& emsa) :
40 PK_Ops::Signature_with_EMSA(emsa),
41 m_group(ecgdsa.domain()),
42 m_x(ecgdsa.private_value())
46 secure_vector<uint8_t> raw_sign(
const uint8_t msg[],
size_t msg_len,
47 RandomNumberGenerator& rng)
override;
49 size_t signature_length()
const override {
return 2*m_group.get_order_bytes(); }
51 size_t max_input_bits()
const override {
return m_group.get_order_bits(); }
54 const EC_Group m_group;
56 std::vector<BigInt> m_ws;
60ECGDSA_Signature_Operation::raw_sign(
const uint8_t msg[],
size_t msg_len,
61 RandomNumberGenerator& rng)
63 const BigInt m(msg, msg_len, m_group.get_order_bits());
65 const BigInt k = m_group.random_scalar(rng);
67 const BigInt r = m_group.mod_order(
68 m_group.blinded_base_point_multiply_x(k, rng, m_ws));
70 const BigInt kr = m_group.multiply_mod_order(k, r);
72 const BigInt s = m_group.multiply_mod_order(m_x, kr - m);
75 if(r.is_zero() || s.is_zero())
76 throw Internal_Error(
"During ECGDSA signature generated zero r/s");
84class ECGDSA_Verification_Operation
final :
public PK_Ops::Verification_with_EMSA
88 ECGDSA_Verification_Operation(
const ECGDSA_PublicKey& ecgdsa,
89 const std::string& emsa) :
90 PK_Ops::Verification_with_EMSA(emsa),
91 m_group(ecgdsa.domain()),
92 m_gy_mul(m_group.get_base_point(), ecgdsa.public_point())
96 size_t max_input_bits()
const override {
return m_group.get_order_bits(); }
98 bool with_recovery()
const override {
return false; }
100 bool verify(
const uint8_t msg[],
size_t msg_len,
101 const uint8_t sig[],
size_t sig_len)
override;
103 const EC_Group m_group;
104 const PointGFp_Multi_Point_Precompute m_gy_mul;
107bool ECGDSA_Verification_Operation::verify(
const uint8_t msg[],
size_t msg_len,
108 const uint8_t sig[],
size_t sig_len)
110 if(sig_len != m_group.get_order_bytes() * 2)
113 const BigInt e(msg, msg_len, m_group.get_order_bits());
115 const BigInt r(sig, sig_len / 2);
116 const BigInt s(sig + sig_len / 2, sig_len / 2);
118 if(r <= 0 || r >= m_group.get_order() || s <= 0 || s >= m_group.get_order())
121 const BigInt w = m_group.inverse_mod_order(r);
123 const BigInt u1 = m_group.multiply_mod_order(e, w);
124 const BigInt u2 = m_group.multiply_mod_order(s, w);
125 const PointGFp R = m_gy_mul.
multi_exp(u1, u2);
130 const BigInt v = m_group.mod_order(R.get_affine_x());
136std::unique_ptr<PK_Ops::Verification>
138 const std::string& provider)
const
140 if(provider ==
"base" || provider.empty())
141 return std::unique_ptr<PK_Ops::Verification>(
new ECGDSA_Verification_Operation(*
this, params));
145std::unique_ptr<PK_Ops::Signature>
147 const std::string& params,
148 const std::string& provider)
const
150 if(provider ==
"base" || provider.empty())
151 return std::unique_ptr<PK_Ops::Signature>(
new ECGDSA_Signature_Operation(*
this, params));
static secure_vector< uint8_t > encode_fixed_length_int_pair(const BigInt &n1, const BigInt &n2, size_t bytes)
std::unique_ptr< PK_Ops::Signature > create_signature_op(RandomNumberGenerator &rng, const std::string ¶ms, const std::string &provider) const override
bool check_key(RandomNumberGenerator &rng, bool) const override
std::string algo_name() const override
std::unique_ptr< PK_Ops::Verification > create_verification_op(const std::string ¶ms, const std::string &provider) const override
const PointGFp & public_point() const
PointGFp multi_exp(const BigInt &k1, const BigInt &k2) const
int(* final)(unsigned char *, CTX *)
bool signature_consistency_check(RandomNumberGenerator &rng, const Private_Key &private_key, const Public_Key &public_key, const std::string &padding)