9#include <botan/eckcdsa.h>
10#include <botan/internal/pk_ops_impl.h>
11#include <botan/internal/point_mul.h>
12#include <botan/internal/keypair.h>
13#include <botan/reducer.h>
14#include <botan/internal/emsa.h>
15#include <botan/hash.h>
51 const std::string& emsa) :
52 PK_Ops::Signature_with_EMSA(emsa),
53 m_group(eckcdsa.domain()),
54 m_x(eckcdsa.private_value()),
60 const size_t order_bytes = m_group.get_order_bytes();
62 m_prefix.resize(2*order_bytes);
68 m_prefix.resize(block_size);
71 secure_vector<uint8_t> raw_sign(
const uint8_t msg[],
size_t msg_len,
72 RandomNumberGenerator& rng)
override;
74 size_t signature_length()
const override {
return 2*m_group.get_order_bytes(); }
75 size_t max_input_bits()
const override {
return m_group.get_order_bits(); }
77 bool has_prefix()
override {
return true; }
78 secure_vector<uint8_t> message_prefix()
const override {
return m_prefix; }
81 const EC_Group m_group;
83 secure_vector<uint8_t> m_prefix;
84 std::vector<BigInt> m_ws;
88ECKCDSA_Signature_Operation::raw_sign(
const uint8_t msg[],
size_t ,
89 RandomNumberGenerator& rng)
91 const BigInt k = m_group.random_scalar(rng);
92 const BigInt k_times_P_x = m_group.blinded_base_point_multiply_x(k, rng, m_ws);
94 secure_vector<uint8_t> to_be_hashed(k_times_P_x.bytes());
95 k_times_P_x.binary_encode(to_be_hashed.data());
97 std::unique_ptr<EMSA> emsa = this->clone_emsa();
98 emsa->update(to_be_hashed.data(), to_be_hashed.size());
99 secure_vector<uint8_t> c = emsa->raw_data();
100 c = emsa->encoding_of(c, max_input_bits(), rng);
102 const BigInt r(c.data(), c.size());
105 BigInt w(c.data(), c.size());
106 w = m_group.mod_order(w);
108 const BigInt s = m_group.multiply_mod_order(m_x, k - w);
110 throw Internal_Error(
"During ECKCDSA signature generation created zero s");
120class ECKCDSA_Verification_Operation
final :
public PK_Ops::Verification_with_EMSA
124 ECKCDSA_Verification_Operation(
const ECKCDSA_PublicKey& eckcdsa,
125 const std::string& emsa) :
126 PK_Ops::Verification_with_EMSA(emsa),
127 m_group(eckcdsa.domain()),
128 m_gy_mul(m_group.get_base_point(), eckcdsa.public_point()),
131 const BigInt public_point_x = eckcdsa.public_point().get_affine_x();
132 const BigInt public_point_y = eckcdsa.public_point().get_affine_y();
134 const size_t order_bytes = m_group.get_order_bytes();
136 m_prefix.resize(2*order_bytes);
142 m_prefix.resize(block_size);
145 bool has_prefix()
override {
return true; }
146 secure_vector<uint8_t> message_prefix()
const override {
return m_prefix; }
148 size_t max_input_bits()
const override {
return m_group.get_order_bits(); }
150 bool with_recovery()
const override {
return false; }
152 bool verify(
const uint8_t msg[],
size_t msg_len,
153 const uint8_t sig[],
size_t sig_len)
override;
155 const EC_Group m_group;
156 const PointGFp_Multi_Point_Precompute m_gy_mul;
157 secure_vector<uint8_t> m_prefix;
160bool ECKCDSA_Verification_Operation::verify(
const uint8_t msg[],
size_t ,
161 const uint8_t sig[],
size_t sig_len)
166 const size_t order_bytes = m_group.get_order_bytes();
168 const size_t size_r = std::min(
hash -> output_length(), order_bytes);
169 if(sig_len != size_r + order_bytes)
174 secure_vector<uint8_t> r(sig, sig + size_r);
177 const BigInt s(sig + size_r, order_bytes);
179 if(s <= 0 || s >= m_group.get_order())
184 secure_vector<uint8_t> r_xor_e(r);
185 xor_buf(r_xor_e, msg, r.size());
186 BigInt w(r_xor_e.data(), r_xor_e.size());
187 w = m_group.mod_order(w);
189 const PointGFp q = m_gy_mul.
multi_exp(w, s);
196 secure_vector<uint8_t> c(q_x.bytes());
197 q_x.binary_encode(c.data());
198 std::unique_ptr<EMSA> emsa = this->clone_emsa();
199 emsa->update(c.data(), c.size());
200 secure_vector<uint8_t>
v = emsa->raw_data();
202 v = emsa->encoding_of(
v, max_input_bits(), rng);
209std::unique_ptr<PK_Ops::Verification>
211 const std::string& provider)
const
213 if(provider ==
"base" || provider.empty())
214 return std::make_unique<ECKCDSA_Verification_Operation>(*
this, params);
218std::unique_ptr<PK_Ops::Signature>
220 const std::string& params,
221 const std::string& provider)
const
223 if(provider ==
"base" || provider.empty())
224 return std::make_unique<ECKCDSA_Signature_Operation>(*
this, params);
static secure_vector< uint8_t > encode_1363(const BigInt &n, size_t bytes)
std::unique_ptr< PK_Ops::Signature > create_signature_op(RandomNumberGenerator &rng, const std::string ¶ms, const std::string &provider) const override
std::unique_ptr< Public_Key > public_key() 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 EC_Group & domain() const
const PointGFp & public_point() const
static std::unique_ptr< HashFunction > create(const std::string &algo_spec, const std::string &provider="")
PointGFp multi_exp(const BigInt &k1, const BigInt &k2) const
BigInt get_affine_y() const
BigInt get_affine_x() 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)
void xor_buf(uint8_t out[], const uint8_t in[], size_t length)