diff options
Diffstat (limited to 'comm/third_party/botan/src/lib/pubkey/gost_3410/gost_3410.cpp')
| -rw-r--r-- | comm/third_party/botan/src/lib/pubkey/gost_3410/gost_3410.cpp | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/pubkey/gost_3410/gost_3410.cpp b/comm/third_party/botan/src/lib/pubkey/gost_3410/gost_3410.cpp new file mode 100644 index 0000000000..d1f8fc7867 --- /dev/null +++ b/comm/third_party/botan/src/lib/pubkey/gost_3410/gost_3410.cpp @@ -0,0 +1,253 @@ +/* +* GOST 34.10-2012 +* (C) 2007 Falko Strenzke, FlexSecure GmbH +* Manuel Hartl, FlexSecure GmbH +* (C) 2008-2010,2015,2018 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/gost_3410.h> +#include <botan/internal/pk_ops_impl.h> +#include <botan/internal/point_mul.h> +#include <botan/reducer.h> +#include <botan/der_enc.h> +#include <botan/ber_dec.h> + +namespace Botan { + +std::vector<uint8_t> GOST_3410_PublicKey::public_key_bits() const + { + const BigInt x = public_point().get_affine_x(); + const BigInt y = public_point().get_affine_y(); + + size_t part_size = std::max(x.bytes(), y.bytes()); + + std::vector<uint8_t> bits(2*part_size); + + x.binary_encode(&bits[part_size - x.bytes()]); + y.binary_encode(&bits[2*part_size - y.bytes()]); + + // Keys are stored in little endian format (WTF) + for(size_t i = 0; i != part_size / 2; ++i) + { + std::swap(bits[i], bits[part_size-1-i]); + std::swap(bits[part_size+i], bits[2*part_size-1-i]); + } + + std::vector<uint8_t> output; + DER_Encoder(output).encode(bits, OCTET_STRING); + return output; + } + +std::string GOST_3410_PublicKey::algo_name() const + { + const size_t p_bits = domain().get_p_bits(); + + if(p_bits == 256 || p_bits == 512) + return "GOST-34.10-2012-" + std::to_string(p_bits); + else + throw Encoding_Error("GOST-34.10-2012 is not defined for parameters of this size"); + } + +AlgorithmIdentifier GOST_3410_PublicKey::algorithm_identifier() const + { + std::vector<uint8_t> params; + + const OID gost_oid = get_oid(); + const OID domain_oid = domain().get_curve_oid(); + + DER_Encoder(params).start_cons(SEQUENCE).encode(domain_oid).end_cons(); + + return AlgorithmIdentifier(gost_oid, params); + } + +GOST_3410_PublicKey::GOST_3410_PublicKey(const AlgorithmIdentifier& alg_id, + const std::vector<uint8_t>& key_bits) + { + OID ecc_param_id; + + // The parameters also includes hash and cipher OIDs + BER_Decoder(alg_id.get_parameters()).start_cons(SEQUENCE).decode(ecc_param_id); + + m_domain_params = EC_Group(ecc_param_id); + + const size_t p_bits = m_domain_params.get_p_bits(); + if(p_bits != 256 && p_bits != 512) + throw Decoding_Error("GOST-34.10-2012 is not defined for parameters of size " + + std::to_string(p_bits)); + + secure_vector<uint8_t> bits; + BER_Decoder(key_bits).decode(bits, OCTET_STRING); + + const size_t part_size = bits.size() / 2; + + // Keys are stored in little endian format (WTF) + for(size_t i = 0; i != part_size / 2; ++i) + { + std::swap(bits[i], bits[part_size-1-i]); + std::swap(bits[part_size+i], bits[2*part_size-1-i]); + } + + BigInt x(bits.data(), part_size); + BigInt y(&bits[part_size], part_size); + + m_public_key = domain().point(x, y); + + BOTAN_ASSERT(m_public_key.on_the_curve(), + "Loaded GOST 34.10 public key is on the curve"); + } + +GOST_3410_PrivateKey::GOST_3410_PrivateKey(RandomNumberGenerator& rng, + const EC_Group& domain, + const BigInt& x) : + EC_PrivateKey(rng, domain, x) + { + const size_t p_bits = m_domain_params.get_p_bits(); + if(p_bits != 256 && p_bits != 512) + throw Decoding_Error("GOST-34.10-2012 is not defined for parameters of size " + + std::to_string(p_bits)); + } + +namespace { + +BigInt decode_le(const uint8_t msg[], size_t msg_len) + { + secure_vector<uint8_t> msg_le(msg, msg + msg_len); + + for(size_t i = 0; i != msg_le.size() / 2; ++i) + std::swap(msg_le[i], msg_le[msg_le.size()-1-i]); + + return BigInt(msg_le.data(), msg_le.size()); + } + +/** +* GOST-34.10 signature operation +*/ +class GOST_3410_Signature_Operation final : public PK_Ops::Signature_with_EMSA + { + public: + GOST_3410_Signature_Operation(const GOST_3410_PrivateKey& gost_3410, + const std::string& emsa) : + PK_Ops::Signature_with_EMSA(emsa), + m_group(gost_3410.domain()), + m_x(gost_3410.private_value()) + {} + + size_t signature_length() const override { return 2*m_group.get_order_bytes(); } + + size_t max_input_bits() const override { return m_group.get_order_bits(); } + + secure_vector<uint8_t> raw_sign(const uint8_t msg[], size_t msg_len, + RandomNumberGenerator& rng) override; + + private: + const EC_Group m_group; + const BigInt& m_x; + std::vector<BigInt> m_ws; + }; + +secure_vector<uint8_t> +GOST_3410_Signature_Operation::raw_sign(const uint8_t msg[], size_t msg_len, + RandomNumberGenerator& rng) + { + const BigInt k = m_group.random_scalar(rng); + + BigInt e = decode_le(msg, msg_len); + + e = m_group.mod_order(e); + if(e == 0) + e = 1; + + const BigInt r = m_group.mod_order( + m_group.blinded_base_point_multiply_x(k, rng, m_ws)); + + const BigInt s = m_group.mod_order( + m_group.multiply_mod_order(r, m_x) + + m_group.multiply_mod_order(k, e)); + + if(r == 0 || s == 0) + throw Internal_Error("GOST 34.10 signature generation failed, r/s equal to zero"); + + return BigInt::encode_fixed_length_int_pair(s, r, m_group.get_order_bytes()); + } + +/** +* GOST-34.10 verification operation +*/ +class GOST_3410_Verification_Operation final : public PK_Ops::Verification_with_EMSA + { + public: + + GOST_3410_Verification_Operation(const GOST_3410_PublicKey& gost, + const std::string& emsa) : + PK_Ops::Verification_with_EMSA(emsa), + m_group(gost.domain()), + m_gy_mul(m_group.get_base_point(), gost.public_point()) + {} + + size_t max_input_bits() const override { return m_group.get_order_bits(); } + + bool with_recovery() const override { return false; } + + bool verify(const uint8_t msg[], size_t msg_len, + const uint8_t sig[], size_t sig_len) override; + private: + const EC_Group m_group; + const PointGFp_Multi_Point_Precompute m_gy_mul; + }; + +bool GOST_3410_Verification_Operation::verify(const uint8_t msg[], size_t msg_len, + const uint8_t sig[], size_t sig_len) + { + if(sig_len != m_group.get_order_bytes() * 2) + return false; + + const BigInt s(sig, sig_len / 2); + const BigInt r(sig + sig_len / 2, sig_len / 2); + + const BigInt& order = m_group.get_order(); + + if(r <= 0 || r >= order || s <= 0 || s >= order) + return false; + + BigInt e = decode_le(msg, msg_len); + e = m_group.mod_order(e); + if(e == 0) + e = 1; + + const BigInt v = m_group.inverse_mod_order(e); + + const BigInt z1 = m_group.multiply_mod_order(s, v); + const BigInt z2 = m_group.multiply_mod_order(-r, v); + + const PointGFp R = m_gy_mul.multi_exp(z1, z2); + + if(R.is_zero()) + return false; + + return (R.get_affine_x() == r); + } + +} + +std::unique_ptr<PK_Ops::Verification> +GOST_3410_PublicKey::create_verification_op(const std::string& params, + const std::string& provider) const + { + if(provider == "base" || provider.empty()) + return std::unique_ptr<PK_Ops::Verification>(new GOST_3410_Verification_Operation(*this, params)); + throw Provider_Not_Found(algo_name(), provider); + } + +std::unique_ptr<PK_Ops::Signature> +GOST_3410_PrivateKey::create_signature_op(RandomNumberGenerator& /*rng*/, + const std::string& params, + const std::string& provider) const + { + if(provider == "base" || provider.empty()) + return std::unique_ptr<PK_Ops::Signature>(new GOST_3410_Signature_Operation(*this, params)); + throw Provider_Not_Found(algo_name(), provider); + } + +} |