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crypto: more checks for generate_CLSAG_GGXG

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sowle 2022-10-18 04:29:41 +02:00
parent 76e628d63f
commit ed3b698839
No known key found for this signature in database
GPG key ID: C07A24B2D89D49FC
1 changed files with 31 additions and 5 deletions
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36
src/crypto/clsag.cpp
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@ -14,7 +14,8 @@ namespace crypto
#define DBG_VAL_PRINT(x) (void(0)) // std::cout << #x ": " << x << std::endl
#define DBG_PRINT(x) (void(0)) // std::cout << x << std::endl
//static std::ostream &operator <<(std::ostream &o, const crypto::hash &v) { return o << pod_to_hex(v); }
static std::ostream &operator <<(std::ostream &o, const crypto::hash &v) { return o << pod_to_hex(v); }
static std::ostream &operator <<(std::ostream &o, const crypto::public_key &v) { return o << pod_to_hex(v); }
bool generate_CLSAG_GG(const hash& m, const std::vector<CLSAG_GG_input_ref_t>& ring, const point_t& pseudo_out_amount_commitment, const key_image& ki,
const scalar_t& secret_x, const scalar_t& secret_f, uint64_t secret_index, CLSAG_GG_signature& sig)
@ -183,7 +184,14 @@ namespace crypto
// calculate key images
point_t ki_base = hash_helper_t::hp(ring[secret_index].stealth_address);
point_t key_image = secret_0_xp * ki_base;
#ifndef NDEBUG
CRYPTO_CHECK_AND_THROW_MES(key_image == point_t(ki), "key image 0 mismatch");
CRYPTO_CHECK_AND_THROW_MES((secret_0_xp * c_point_G).to_public_key() == ring[secret_index].stealth_address, "secret_0_xp mismatch");
CRYPTO_CHECK_AND_THROW_MES(secret_1_f * c_point_G == 8 * point_t(ring[secret_index].amount_commitment) - pseudo_out_amount_commitment, "secret_1_f mismatch");
CRYPTO_CHECK_AND_THROW_MES(secret_3_q * c_point_G == 8 * point_t(ring[secret_index].concealing_point), "secret_3_q mismatch");
CRYPTO_CHECK_AND_THROW_MES(secret_2_x * c_point_X == extended_amount_commitment - 8 * point_t(ring[secret_index].amount_commitment) - 8 * point_t(ring[secret_index].concealing_point), "secret_3_q mismatch");
#endif
point_t K1_div8 = (c_scalar_1div8 * secret_1_f) * ki_base;
K1_div8.to_public_key(sig.K1);
@ -208,6 +216,7 @@ namespace crypto
hsc.add_pub_key(ring[i].stealth_address);
hsc.add_pub_key(ring[i].amount_commitment);
hsc.add_pub_key(ring[i].concealing_point);
DBG_PRINT("ring[" << i << "]: sa:" << ring[i].stealth_address << ", ac:" << ring[i].amount_commitment << ", cp:" << ring[i].concealing_point);
}
hsc.add_point(c_scalar_1div8 * pseudo_out_amount_commitment);
hsc.add_point(c_scalar_1div8 * extended_amount_commitment);
@ -282,21 +291,33 @@ namespace crypto
// calculate aggregate key image (layers 0, 1, 3; G component)
point_t W_key_image_g = agg_coeff_0 * key_image + agg_coeff_1 * K1 + /*agg_coeff_2 * K2 +*/ agg_coeff_3 * K3;
DBG_VAL_PRINT(key_image);
DBG_VAL_PRINT(K1);
DBG_VAL_PRINT(K3);
DBG_VAL_PRINT(W_key_image_g);
// calculate aggregate key image (layer 2; X component)
point_t W_key_image_x = agg_coeff_2 * K2;
DBG_VAL_PRINT(K2);
DBG_VAL_PRINT(W_key_image_x);
#ifndef NDEBUG
CRYPTO_CHECK_AND_THROW_MES(w_sec_key_g * c_point_G == W_pub_keys_g[secret_index], "aggregated secret G and pub key mismatch");
CRYPTO_CHECK_AND_THROW_MES(w_sec_key_g * hash_helper_t::hp(ring[secret_index].stealth_address) == W_key_image_g, "aggregated secret G and key image mismatch");
CRYPTO_CHECK_AND_THROW_MES(w_sec_key_x * c_point_X == W_pub_keys_x[secret_index], "aggregated secret X and pub key mismatch");
CRYPTO_CHECK_AND_THROW_MES(w_sec_key_x * hash_helper_t::hp(ring[secret_index].stealth_address) == W_key_image_x, "aggregated secret X and key image mismatch");
#endif
// initial commitment
scalar_t alpha_g = scalar_t::random(); // randomness for layers 0,1,3
scalar_t alpha_x = scalar_t::random(); // randomness for layer 2
hsc.add_32_chars(CRYPTO_HDS_CLSAG_GGXG_CHALLENGE);
hsc.add_hash(input_hash);
hsc.add_point(alpha_g * c_point_G); DBG_VAL_PRINT(alpha_g * c_point_G);
hsc.add_point(alpha_g * ki_base); DBG_VAL_PRINT(alpha_g * ki_base);
hsc.add_point(alpha_x * c_point_X); DBG_VAL_PRINT(alpha_x * c_point_X);
hsc.add_point(alpha_x * ki_base); DBG_VAL_PRINT(alpha_x * ki_base);
hsc.add_point(alpha_g * c_point_G);
hsc.add_point(alpha_g * ki_base);
hsc.add_point(alpha_x * c_point_X);
hsc.add_point(alpha_x * ki_base);
DBG_PRINT("c[" << secret_index << "] = Hs(ih, " << alpha_g * c_point_G << ", " << alpha_g * ki_base << ", " << alpha_x * c_point_X << ", " << alpha_x * ki_base << ")");
scalar_t c_prev = hsc.calc_hash(); // c_{secret_index + 1}
sig.r_g.clear();
@ -360,6 +381,7 @@ namespace crypto
hsc.add_pub_key(ring[i].stealth_address);
hsc.add_pub_key(ring[i].amount_commitment);
hsc.add_pub_key(ring[i].concealing_point);
DBG_PRINT("ring[" << i << "]: sa:" << ring[i].stealth_address << ", ac:" << ring[i].amount_commitment << ", cp:" << ring[i].concealing_point);
}
hsc.add_pub_key(pseudo_out_amount_commitment);
hsc.add_pub_key(extended_amount_commitment);
@ -429,11 +451,14 @@ namespace crypto
agg_coeff_0 * key_image +
agg_coeff_1 * point_t(sig.K1).modify_mul8() +
agg_coeff_3 * point_t(sig.K3).modify_mul8();
DBG_VAL_PRINT(point_t(sig.K1).modify_mul8());
DBG_VAL_PRINT(point_t(sig.K3).modify_mul8());
DBG_VAL_PRINT(W_key_image_g);
// calculate aggregate key image (layer 2; X component)
point_t W_key_image_x =
agg_coeff_2 * point_t(sig.K2).modify_mul8();
DBG_VAL_PRINT(point_t(sig.K2).modify_mul8());
DBG_VAL_PRINT(W_key_image_x);
@ -449,6 +474,7 @@ namespace crypto
hsc.add_point(sig.r_x[i] * hash_helper_t::hp(ring[i].stealth_address) + c_prev * W_key_image_x);
c_prev = hsc.calc_hash(); // c_{i + 1}
DBG_PRINT("c[" << i + 1 << "] = " << c_prev);
DBG_PRINT("c[" << i + 1 << "] = Hs(ih, " << sig.r_g[i] * c_point_G + c_prev * W_pub_keys_g[i] << ", " << sig.r_g[i] * hash_helper_t::hp(ring[i].stealth_address) + c_prev * W_key_image_g << ", " << sig.r_x[i] * c_point_X + c_prev * W_pub_keys_x[i] << ", " << sig.r_x[i] * hash_helper_t::hp(ring[i].stealth_address) + c_prev * W_key_image_x << ")");
}
return c_prev == sig.c;