13471882073

Committed 22 Feb 2025 10:03AM UTC coverage: 91.691% (+0.03%) from 91.665%

Build # 13471882073

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github

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web-flow

Commit Message

Merge pull request #4554 from randombit/jack/pcurves-generic

Add generic pcurves for application specific curves

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92.54

/src/lib/pubkey/ec_group/ec_inner_data.cpp

/*
* (C) 2024 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/internal/ec_inner_data.h>

#include <botan/der_enc.h>
#include <botan/internal/ec_inner_pc.h>
#include <botan/internal/fmt.h>
#include <botan/internal/pcurves.h>

#if defined(BOTAN_HAS_LEGACY_EC_POINT)
   #include <botan/internal/ec_inner_bn.h>
   #include <botan/internal/point_mul.h>
#endif

#if defined(BOTAN_HAS_XMD)
   #include <botan/internal/xmd.h>
#endif

namespace Botan {

EC_Group_Data::~EC_Group_Data() = default;

// Note this constructor *does not* initialize m_curve, m_base_point or m_base_mult
EC_Group_Data::EC_Group_Data(const BigInt& p,
                             const BigInt& a,
                             const BigInt& b,
                             const BigInt& g_x,
                             const BigInt& g_y,
                             const BigInt& order,
                             const BigInt& cofactor,
                             const OID& oid,
                             EC_Group_Source source) :
      m_p(p),
      m_a(a),
      m_b(b),
      m_g_x(g_x),
      m_g_y(g_y),
      m_order(order),
      m_cofactor(cofactor),
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      m_mod_field(Modular_Reducer::for_public_modulus(p)),
      m_mod_order(Modular_Reducer::for_public_modulus(order)),
      m_monty(m_p, m_mod_field),
#endif
      m_oid(oid),
      m_p_words(p.sig_words()),
      m_p_bits(p.bits()),
      m_order_bits(order.bits()),
      m_order_bytes((m_order_bits + 7) / 8),
      m_a_is_minus_3(a == p - 3),
      m_a_is_zero(a.is_zero()),
      m_has_cofactor(m_cofactor != 1),
      m_order_is_less_than_p(m_order < p),
      m_source(source) {
   // TODO(Botan4) we can assume/assert the OID is set
   if(!m_oid.empty()) {
      DER_Encoder der(m_der_named_curve);
      der.encode(m_oid);

      const std::string name = m_oid.human_name_or_empty();
      if(!name.empty()) {
         // returns nullptr if unknown or not supported
         m_pcurve = PCurve::PrimeOrderCurve::for_named_curve(name);
      }
      if(m_pcurve) {
         m_engine = EC_Group_Engine::Optimized;
      }
   }

   // Try a generic pcurves instance
   if(!m_pcurve && !m_has_cofactor) {
      m_pcurve = PCurve::PrimeOrderCurve::from_params(p, a, b, g_x, g_y, order);
      if(m_pcurve) {
         m_engine = EC_Group_Engine::Generic;
      }
      // possibly still null here, if parameters unsuitable or if the
      // pcurves_generic module wasn't included in the build
   }

#if defined(BOTAN_HAS_LEGACY_EC_POINT)
   secure_vector<word> ws;
   m_a_r = m_monty.mul(a, m_monty.R2(), ws);
   m_b_r = m_monty.mul(b, m_monty.R2(), ws);
   if(!m_pcurve) {
      m_engine = EC_Group_Engine::Legacy;
   }
#else
   if(!m_pcurve) {
      if(m_oid.empty()) {
         throw Not_Implemented("EC_Group this group is not supported in this build configuration");
      } else {
         throw Not_Implemented(
            fmt("EC_Group the group {} is not supported in this build configuration", oid.to_string()));
      }
   }
#endif
}

std::shared_ptr<EC_Group_Data> EC_Group_Data::create(const BigInt& p,
                                                     const BigInt& a,
                                                     const BigInt& b,
                                                     const BigInt& g_x,
                                                     const BigInt& g_y,
                                                     const BigInt& order,
                                                     const BigInt& cofactor,
                                                     const OID& oid,
                                                     EC_Group_Source source) {
   auto group = std::make_shared<EC_Group_Data>(p, a, b, g_x, g_y, order, cofactor, oid, source);

#if defined(BOTAN_HAS_LEGACY_EC_POINT)
   group->m_curve = CurveGFp(group.get());
   group->m_base_point = EC_Point(group->m_curve, g_x, g_y);
   if(!group->m_pcurve) {
      group->m_base_mult = std::make_unique<EC_Point_Base_Point_Precompute>(group->m_base_point, group->m_mod_order);
   }
#endif

   return group;
}

bool EC_Group_Data::params_match(const BigInt& p,
                                 const BigInt& a,
                                 const BigInt& b,
                                 const BigInt& g_x,
                                 const BigInt& g_y,
                                 const BigInt& order,
                                 const BigInt& cofactor) const {
   return (this->p() == p && this->a() == a && this->b() == b && this->order() == order &&
           this->cofactor() == cofactor && this->g_x() == g_x && this->g_y() == g_y);
}

bool EC_Group_Data::params_match(const EC_Group_Data& other) const {
   return params_match(other.p(), other.a(), other.b(), other.g_x(), other.g_y(), other.order(), other.cofactor());
}

void EC_Group_Data::set_oid(const OID& oid) {
   BOTAN_ARG_CHECK(!oid.empty(), "OID should be set");
   BOTAN_STATE_CHECK(m_oid.empty() && m_der_named_curve.empty());
   m_oid = oid;

   DER_Encoder der(m_der_named_curve);
   der.encode(m_oid);
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_from_bytes_with_trunc(std::span<const uint8_t> bytes) const {
   const size_t bit_length = 8 * bytes.size();

   if(bit_length < order_bits()) {
      // No shifting required, but might still need to reduce by modulus
      return this->scalar_from_bytes_mod_order(bytes);
   } else {
      const size_t shift = bit_length - order_bits();

      const size_t new_length = bytes.size() - (shift / 8);
      const size_t bit_shift = shift % 8;

      if(bit_shift == 0) {
         // Easy case just read different bytes
         return this->scalar_from_bytes_mod_order(bytes.first(new_length));
      } else {
         std::vector<uint8_t> sbytes(new_length);

         uint8_t carry = 0;
         for(size_t i = 0; i != new_length; ++i) {
            const uint8_t w = bytes[i];
            sbytes[i] = (w >> bit_shift) | carry;
            carry = w << (8 - bit_shift);
         }

         return this->scalar_from_bytes_mod_order(sbytes);
      }
   }
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_from_bytes_mod_order(std::span<const uint8_t> bytes) const {
   if(bytes.size() > 2 * order_bytes()) {
      return {};
   }

   if(m_pcurve) {
      if(auto s = m_pcurve->scalar_from_wide_bytes(bytes)) {
         return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), std::move(*s));
      } else {
         return {};
      }
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), m_mod_order.reduce(BigInt(bytes)));
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_random(RandomNumberGenerator& rng) const {
   if(m_pcurve) {
      return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), m_pcurve->random_scalar(rng));
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(),
                                                 BigInt::random_integer(rng, BigInt::one(), m_order));
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_one() const {
   if(m_pcurve) {
      return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), m_pcurve->scalar_one());
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), BigInt::one());
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_from_bigint(const BigInt& bn) const {
   if(bn <= 0 || bn >= m_order) {
      return {};
   }

   if(m_pcurve) {
      return this->scalar_deserialize(bn.serialize(m_order_bytes));
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), bn);
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::gk_x_mod_order(const EC_Scalar_Data& scalar,
                                                              RandomNumberGenerator& rng,
                                                              std::vector<BigInt>& ws) const {
   if(m_pcurve) {
      const auto& k = EC_Scalar_Data_PC::checked_ref(scalar);
      auto gk_x_mod_order = m_pcurve->base_point_mul_x_mod_order(k.value(), rng);
      return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), gk_x_mod_order);
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      const auto& k = EC_Scalar_Data_BN::checked_ref(scalar);
      BOTAN_STATE_CHECK(m_base_mult != nullptr);
      const auto pt = m_base_mult->mul(k.value(), rng, m_order, ws);

      if(pt.is_zero()) {
         return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), BigInt::zero());
      } else {
         return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), m_mod_order.reduce(pt.get_affine_x()));
      }
#else
      BOTAN_UNUSED(ws);
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_deserialize(std::span<const uint8_t> bytes) const {
   if(bytes.size() != m_order_bytes) {
      return nullptr;
   }

   if(m_pcurve) {
      if(auto s = m_pcurve->deserialize_scalar(bytes)) {
         return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), *s);
      } else {
         return nullptr;
      }
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      BigInt r(bytes);

      if(r.is_zero() || r >= m_order) {
         return nullptr;
      }

      return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), std::move(r));
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_deserialize(std::span<const uint8_t> bytes) const {
   // The deprecated "hybrid" point format
   // TODO(Botan4) remove this
   if(bytes.size() >= 1 + 2 * 4 && (bytes[0] == 0x06 || bytes[0] == 0x07)) {
      bool hdr_y_is_even = bytes[0] == 0x06;
      bool y_is_even = (bytes.back() & 0x01) == 0;

      if(hdr_y_is_even == y_is_even) {
         std::vector<uint8_t> sec1(bytes.begin(), bytes.end());
         sec1[0] = 0x04;
         return this->point_deserialize(sec1);
      }
   }

   try {
      if(m_pcurve) {
         if(auto pt = m_pcurve->deserialize_point(bytes)) {
            return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), std::move(*pt));
         } else {
            return {};
         }
      } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
         auto pt = Botan::OS2ECP(bytes, m_curve);
         return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));
#else
         throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
      }
   } catch(...) {
      return {};
   }
}

namespace {

std::function<void(std::span<uint8_t>)> h2c_expand_message(std::string_view hash_fn,
                                                           std::span<const uint8_t> input,
                                                           std::span<const uint8_t> domain_sep) {
   /*
   * This could be extended to support expand_message_xof or a MHF like Argon2
   */

   if(hash_fn.starts_with("SHAKE")) {
      throw Not_Implemented("Hash to curve currently does not support expand_message_xof");
   }

   return [=](std::span<uint8_t> uniform_bytes) {
#if defined(BOTAN_HAS_XMD)
      expand_message_xmd(hash_fn, uniform_bytes, input, domain_sep);
#else
      BOTAN_UNUSED(hash_fn, uniform_bytes, input, domain_sep);
      throw Not_Implemented("Hash to curve is not implemented due to XMD being disabled");
#endif
   };
}

}  // namespace

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_hash_to_curve_ro(std::string_view hash_fn,
                                                                           std::span<const uint8_t> input,
                                                                           std::span<const uint8_t> domain_sep) const {
   if(m_pcurve) {
      auto pt = m_pcurve->hash_to_curve_ro(h2c_expand_message(hash_fn, input, domain_sep));
      return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), m_pcurve->point_to_affine(pt));
   } else {
      throw Not_Implemented("Hash to curve is not implemented for this curve");
   }
}

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_hash_to_curve_nu(std::string_view hash_fn,
                                                                           std::span<const uint8_t> input,
                                                                           std::span<const uint8_t> domain_sep) const {
   if(m_pcurve) {
      auto pt = m_pcurve->hash_to_curve_nu(h2c_expand_message(hash_fn, input, domain_sep));
      return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), std::move(pt));
   } else {
      throw Not_Implemented("Hash to curve is not implemented for this curve");
   }
}

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_g_mul(const EC_Scalar_Data& scalar,
                                                                RandomNumberGenerator& rng,
                                                                std::vector<BigInt>& ws) const {
   if(m_pcurve) {
      const auto& k = EC_Scalar_Data_PC::checked_ref(scalar);
      auto pt = m_pcurve->point_to_affine(m_pcurve->mul_by_g(k.value(), rng));
      return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), std::move(pt));
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      const auto& group = scalar.group();
      const auto& bn = EC_Scalar_Data_BN::checked_ref(scalar);

      BOTAN_STATE_CHECK(group->m_base_mult != nullptr);
      auto pt = group->m_base_mult->mul(bn.value(), rng, m_order, ws);
      return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));
#else
      BOTAN_UNUSED(ws);
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::mul_px_qy(const EC_AffinePoint_Data& p,
                                                              const EC_Scalar_Data& x,
                                                              const EC_AffinePoint_Data& q,
                                                              const EC_Scalar_Data& y,
                                                              RandomNumberGenerator& rng) const {
   if(m_pcurve) {
      auto pt = m_pcurve->mul_px_qy(EC_AffinePoint_Data_PC::checked_ref(p).value(),
                                    EC_Scalar_Data_PC::checked_ref(x).value(),
                                    EC_AffinePoint_Data_PC::checked_ref(q).value(),
                                    EC_Scalar_Data_PC::checked_ref(y).value(),
                                    rng);

      if(pt) {
         return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), m_pcurve->point_to_affine(*pt));
      } else {
         return nullptr;
      }
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      std::vector<BigInt> ws;
      const auto& group = p.group();

      // TODO this could be better!
      EC_Point_Var_Point_Precompute p_mul(p.to_legacy_point(), rng, ws);
      EC_Point_Var_Point_Precompute q_mul(q.to_legacy_point(), rng, ws);

      const auto order = group->order() * group->cofactor();  // See #3800

      auto px = p_mul.mul(EC_Scalar_Data_BN::checked_ref(x).value(), rng, order, ws);
      auto qy = q_mul.mul(EC_Scalar_Data_BN::checked_ref(y).value(), rng, order, ws);

      auto px_qy = px + qy;

      if(!px_qy.is_zero()) {
         px_qy.force_affine();
         return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(px_qy));
      } else {
         return nullptr;
      }
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::affine_add(const EC_AffinePoint_Data& p,
                                                               const EC_AffinePoint_Data& q) const {
   if(m_pcurve) {
      auto pt = m_pcurve->point_add(EC_AffinePoint_Data_PC::checked_ref(p).value(),
                                    EC_AffinePoint_Data_PC::checked_ref(q).value());

      return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), m_pcurve->point_to_affine(pt));
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      auto pt = p.to_legacy_point() + q.to_legacy_point();
      return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::affine_neg(const EC_AffinePoint_Data& p) const {
   if(m_pcurve) {
      auto pt = m_pcurve->point_negate(EC_AffinePoint_Data_PC::checked_ref(p).value());
      return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), pt);
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      auto pt = p.to_legacy_point();
      pt.negate();  // negates in place
      return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

std::unique_ptr<EC_Mul2Table_Data> EC_Group_Data::make_mul2_table(const EC_AffinePoint_Data& h) const {
   if(m_pcurve) {
      return std::make_unique<EC_Mul2Table_Data_PC>(h);
   } else {
#if defined(BOTAN_HAS_LEGACY_EC_POINT)
      EC_AffinePoint_Data_BN g(shared_from_this(), this->base_point());
      return std::make_unique<EC_Mul2Table_Data_BN>(g, h);
#else
      throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
#endif
   }
}

}  // namespace Botan

1	/*
2	* (C) 2024 Jack Lloyd
3	*
4	* Botan is released under the Simplified BSD License (see license.txt)
5	*/
6
7	#include <botan/internal/ec_inner_data.h>
8
9	#include <botan/der_enc.h>
10	#include <botan/internal/ec_inner_pc.h>
11	#include <botan/internal/fmt.h>
12	#include <botan/internal/pcurves.h>
13
14	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
15	#include <botan/internal/ec_inner_bn.h>
16	#include <botan/internal/point_mul.h>
17	#endif
18
19	#if defined(BOTAN_HAS_XMD)
20	#include <botan/internal/xmd.h>
21	#endif
22
23	namespace Botan {
24
25	EC_Group_Data::~EC_Group_Data() = default;	5,772✔
26
27	// Note this constructor does not initialize m_curve, m_base_point or m_base_mult
28	EC_Group_Data::EC_Group_Data(const BigInt& p,	1,155✔
29	const BigInt& a,
30	const BigInt& b,
31	const BigInt& g_x,
32	const BigInt& g_y,
33	const BigInt& order,
34	const BigInt& cofactor,
35	const OID& oid,
36	EC_Group_Source source) :	1,155✔
37	m_p(p),	1,155✔
38	m_a(a),	1,155✔
39	m_b(b),	1,155✔
40	m_g_x(g_x),	1,155✔
41	m_g_y(g_y),	1,155✔
42	m_order(order),	1,155✔
43	m_cofactor(cofactor),	1,155✔
44	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
45	m_mod_field(Modular_Reducer::for_public_modulus(p)),	1,155✔
46	m_mod_order(Modular_Reducer::for_public_modulus(order)),	1,155✔
47	m_monty(m_p, m_mod_field),	1,155✔
48	#endif
49	m_oid(oid),	1,155✔
50	m_p_words(p.sig_words()),	1,155✔
51	m_p_bits(p.bits()),	1,155✔
52	m_order_bits(order.bits()),	1,155✔
53	m_order_bytes((m_order_bits + 7) / 8),	1,155✔
54	m_a_is_minus_3(a == p - 3),	1,155✔
55	m_a_is_zero(a.is_zero()),	1,155✔
56	m_has_cofactor(m_cofactor != 1),	1,155✔
57	m_order_is_less_than_p(m_order < p),	1,155✔
58	m_source(source) {	3,465✔
59	// TODO(Botan4) we can assume/assert the OID is set
60	if(!m_oid.empty()) {	1,155✔
61	DER_Encoder der(m_der_named_curve);	1,152✔
62	der.encode(m_oid);	1,152✔
63
64	const std::string name = m_oid.human_name_or_empty();	1,152✔
65	if(!name.empty()) {	1,152✔
66	// returns nullptr if unknown or not supported
67	m_pcurve = PCurve::PrimeOrderCurve::for_named_curve(name);	1,147✔
68	}
69	if(m_pcurve) {	1,152✔
70	m_engine = EC_Group_Engine::Optimized;	912✔
71	}
72	}	1,152✔
73
74	// Try a generic pcurves instance
75	if(!m_pcurve && !m_has_cofactor) {	1,155✔
76	m_pcurve = PCurve::PrimeOrderCurve::from_params(p, a, b, g_x, g_y, order);	242✔
77	if(m_pcurve) {	242✔
78	m_engine = EC_Group_Engine::Generic;	143✔
79	}
80	// possibly still null here, if parameters unsuitable or if the
81	// pcurves_generic module wasn't included in the build
82	}
83
84	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
85	secure_vector<word> ws;	1,155✔
86	m_a_r = m_monty.mul(a, m_monty.R2(), ws);	2,310✔
87	m_b_r = m_monty.mul(b, m_monty.R2(), ws);	2,310✔
88	if(!m_pcurve) {	1,155✔
89	m_engine = EC_Group_Engine::Legacy;	100✔
90	}
91	#else
92	if(!m_pcurve) {
93	if(m_oid.empty()) {
94	throw Not_Implemented("EC_Group this group is not supported in this build configuration");
95	} else {
96	throw Not_Implemented(
97	fmt("EC_Group the group {} is not supported in this build configuration", oid.to_string()));
98	}
99	}
100	#endif
101	}	1,155✔
102
103	std::shared_ptr<EC_Group_Data> EC_Group_Data::create(const BigInt& p,	1,155✔
104	const BigInt& a,
105	const BigInt& b,
106	const BigInt& g_x,
107	const BigInt& g_y,
108	const BigInt& order,
109	const BigInt& cofactor,
110	const OID& oid,
111	EC_Group_Source source) {
112	auto group = std::make_shared<EC_Group_Data>(p, a, b, g_x, g_y, order, cofactor, oid, source);	1,155✔
113
114	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
115	group->m_curve = CurveGFp(group.get());	1,155✔
116	group->m_base_point = EC_Point(group->m_curve, g_x, g_y);	2,310✔
117	if(!group->m_pcurve) {	1,155✔
118	group->m_base_mult = std::make_unique<EC_Point_Base_Point_Precompute>(group->m_base_point, group->m_mod_order);	100✔
119	}
120	#endif
121
122	return group;	1,155✔
123	}	×
124
125	bool EC_Group_Data::params_match(const BigInt& p,	777✔
126	const BigInt& a,
127	const BigInt& b,
128	const BigInt& g_x,
129	const BigInt& g_y,
130	const BigInt& order,
131	const BigInt& cofactor) const {
132	return (this->p() == p && this->a() == a && this->b() == b && this->order() == order &&	878✔
133	this->cofactor() == cofactor && this->g_x() == g_x && this->g_y() == g_y);	869✔
134	}
135
136	bool EC_Group_Data::params_match(const EC_Group_Data& other) const {	×
137	return params_match(other.p(), other.a(), other.b(), other.g_x(), other.g_y(), other.order(), other.cofactor());	×
138	}
139
140	void EC_Group_Data::set_oid(const OID& oid) {	×
141	BOTAN_ARG_CHECK(!oid.empty(), "OID should be set");	×
142	BOTAN_STATE_CHECK(m_oid.empty() && m_der_named_curve.empty());	×
143	m_oid = oid;	×
144
145	DER_Encoder der(m_der_named_curve);	×
146	der.encode(m_oid);	×
147	}	×
148
149	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_from_bytes_with_trunc(std::span<const uint8_t> bytes) const {	26,074✔
150	const size_t bit_length = 8 * bytes.size();	26,074✔
151
152	if(bit_length < order_bits()) {	26,074✔
153	// No shifting required, but might still need to reduce by modulus
154	return this->scalar_from_bytes_mod_order(bytes);	5,248✔
155	} else {
156	const size_t shift = bit_length - order_bits();	20,826✔
157
158	const size_t new_length = bytes.size() - (shift / 8);	20,826✔
159	const size_t bit_shift = shift % 8;	20,826✔
160
161	if(bit_shift == 0) {	20,826✔
162	// Easy case just read different bytes
163	return this->scalar_from_bytes_mod_order(bytes.first(new_length));	18,167✔
164	} else {
165	std::vector<uint8_t> sbytes(new_length);	2,659✔
166
167	uint8_t carry = 0;	2,659✔
168	for(size_t i = 0; i != new_length; ++i) {	72,637✔
169	const uint8_t w = bytes[i];	69,978✔
170	sbytes[i] = (w >> bit_shift) \| carry;	69,978✔
171	carry = w << (8 - bit_shift);	69,978✔
172	}
173
174	return this->scalar_from_bytes_mod_order(sbytes);	2,659✔
175	}	2,659✔
176	}
177	}
178
179	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_from_bytes_mod_order(std::span<const uint8_t> bytes) const {	34,790✔
180	if(bytes.size() > 2 * order_bytes()) {	34,790✔
181	return {};	×
182	}
183
184	if(m_pcurve) {	34,790✔
185	if(auto s = m_pcurve->scalar_from_wide_bytes(bytes)) {	31,970✔
186	return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), std::move(*s));	31,970✔
187	} else {
188	return {};	×
189	}	31,970✔
190	} else {
191	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
192	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), m_mod_order.reduce(BigInt(bytes)));	2,820✔
193	#else
194	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
195	#endif
196	}
197	}
198
199	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_random(RandomNumberGenerator& rng) const {	44,362✔
200	if(m_pcurve) {	44,362✔
201	return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), m_pcurve->random_scalar(rng));	76,342✔
202	} else {
203	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
204	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(),	12,382✔
205	BigInt::random_integer(rng, BigInt::one(), m_order));	18,573✔
206	#else
207	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
208	#endif
209	}
210	}
211
212	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_one() const {	101✔
213	if(m_pcurve) {	101✔
214	return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), m_pcurve->scalar_one());	93✔
215	} else {
216	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
217	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), BigInt::one());	8✔
218	#else
219	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
220	#endif
221	}
222	}
223
224	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_from_bigint(const BigInt& bn) const {	4,484✔
225	if(bn <= 0 \|\| bn >= m_order) {	4,484✔
226	return {};	×
227	}
228
229	if(m_pcurve) {	4,484✔
230	return this->scalar_deserialize(bn.serialize(m_order_bytes));	8,146✔
231	} else {
232	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
233	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), bn);	411✔
234	#else
235	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
236	#endif
237	}
238	}
239
240	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::gk_x_mod_order(const EC_Scalar_Data& scalar,	3,312✔
241	RandomNumberGenerator& rng,
242	std::vector<BigInt>& ws) const {
243	if(m_pcurve) {	3,312✔
244	const auto& k = EC_Scalar_Data_PC::checked_ref(scalar);	2,913✔
245	auto gk_x_mod_order = m_pcurve->base_point_mul_x_mod_order(k.value(), rng);	2,913✔
246	return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), gk_x_mod_order);	2,913✔
247	} else {	2,913✔
248	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
249	const auto& k = EC_Scalar_Data_BN::checked_ref(scalar);	399✔
250	BOTAN_STATE_CHECK(m_base_mult != nullptr);	399✔
251	const auto pt = m_base_mult->mul(k.value(), rng, m_order, ws);	399✔
252
253	if(pt.is_zero()) {	798✔
254	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), BigInt::zero());	×
255	} else {
256	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), m_mod_order.reduce(pt.get_affine_x()));	399✔
257	}
258	#else
259	BOTAN_UNUSED(ws);
260	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
261	#endif
262	}	399✔
263	}
264
265	std::unique_ptr<EC_Scalar_Data> EC_Group_Data::scalar_deserialize(std::span<const uint8_t> bytes) const {	69,377✔
266	if(bytes.size() != m_order_bytes) {	69,377✔
267	return nullptr;	5,816✔
268	}
269
270	if(m_pcurve) {	63,561✔
271	if(auto s = m_pcurve->deserialize_scalar(bytes)) {	59,233✔
272	return std::make_unique<EC_Scalar_Data_PC>(shared_from_this(), *s);	56,817✔
273	} else {
274	return nullptr;	2,416✔
275	}	59,233✔
276	} else {
277	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
278	BigInt r(bytes);	4,328✔
279
280	if(r.is_zero() \|\| r >= m_order) {	8,656✔
281	return nullptr;	456✔
282	}
283
284	return std::make_unique<EC_Scalar_Data_BN>(shared_from_this(), std::move(r));	3,872✔
285	#else
286	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
287	#endif
288	}	4,328✔
289	}
290
291	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_deserialize(std::span<const uint8_t> bytes) const {	44,555✔
292	// The deprecated "hybrid" point format
293	// TODO(Botan4) remove this
294	if(bytes.size() >= 1 + 2 * 4 && (bytes[0] == 0x06 \|\| bytes[0] == 0x07)) {	44,555✔
295	bool hdr_y_is_even = bytes[0] == 0x06;	207✔
296	bool y_is_even = (bytes.back() & 0x01) == 0;	207✔
297
298	if(hdr_y_is_even == y_is_even) {	207✔
299	std::vector<uint8_t> sec1(bytes.begin(), bytes.end());	147✔
300	sec1[0] = 0x04;	147✔
301	return this->point_deserialize(sec1);	147✔
302	}	147✔
303	}
304
305	try {	44,408✔
306	if(m_pcurve) {	44,408✔
307	if(auto pt = m_pcurve->deserialize_point(bytes)) {	41,654✔
308	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), std::move(*pt));	35,335✔
309	} else {
310	return {};	6,319✔
311	}	41,654✔
312	} else {
313	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
314	auto pt = Botan::OS2ECP(bytes, m_curve);	2,754✔
315	return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));	2,698✔
316	#else
317	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
318	#endif
319	}	2,698✔
320	} catch(...) {	56✔
321	return {};	56✔
322	}	56✔
323	}
324
325	namespace {
326
327	std::function<void(std::span<uint8_t>)> h2c_expand_message(std::string_view hash_fn,	57✔
328	std::span<const uint8_t> input,
329	std::span<const uint8_t> domain_sep) {
330	/*
331	* This could be extended to support expand_message_xof or a MHF like Argon2
332	*/
333
334	if(hash_fn.starts_with("SHAKE")) {	57✔
335	throw Not_Implemented("Hash to curve currently does not support expand_message_xof");	×
336	}
337
338	return [=](std::span<uint8_t> uniform_bytes) {	168✔
339	#if defined(BOTAN_HAS_XMD)
340	expand_message_xmd(hash_fn, uniform_bytes, input, domain_sep);	54✔
341	#else
342	BOTAN_UNUSED(hash_fn, uniform_bytes, input, domain_sep);
343	throw Not_Implemented("Hash to curve is not implemented due to XMD being disabled");
344	#endif
345	};	57✔
346	}
347
348	} // namespace
349
350	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_hash_to_curve_ro(std::string_view hash_fn,	24✔
351	std::span<const uint8_t> input,
352	std::span<const uint8_t> domain_sep) const {
353	if(m_pcurve) {	24✔
354	auto pt = m_pcurve->hash_to_curve_ro(h2c_expand_message(hash_fn, input, domain_sep));	24✔
355	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), m_pcurve->point_to_affine(pt));	24✔
356	} else {	24✔
357	throw Not_Implemented("Hash to curve is not implemented for this curve");	×
358	}
359	}
360
361	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_hash_to_curve_nu(std::string_view hash_fn,	33✔
362	std::span<const uint8_t> input,
363	std::span<const uint8_t> domain_sep) const {
364	if(m_pcurve) {	33✔
365	auto pt = m_pcurve->hash_to_curve_nu(h2c_expand_message(hash_fn, input, domain_sep));	36✔
366	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), std::move(pt));	30✔
367	} else {	30✔
368	throw Not_Implemented("Hash to curve is not implemented for this curve");	×
369	}
370	}
371
372	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::point_g_mul(const EC_Scalar_Data& scalar,	15,369✔
373	RandomNumberGenerator& rng,
374	std::vector<BigInt>& ws) const {
375	if(m_pcurve) {	15,369✔
376	const auto& k = EC_Scalar_Data_PC::checked_ref(scalar);	13,498✔
377	auto pt = m_pcurve->point_to_affine(m_pcurve->mul_by_g(k.value(), rng));	13,498✔
378	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), std::move(pt));	13,498✔
379	} else {	13,498✔
380	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
381	const auto& group = scalar.group();	1,871✔
382	const auto& bn = EC_Scalar_Data_BN::checked_ref(scalar);	1,871✔
383
384	BOTAN_STATE_CHECK(group->m_base_mult != nullptr);	1,871✔
385	auto pt = group->m_base_mult->mul(bn.value(), rng, m_order, ws);	1,871✔
386	return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));	1,871✔
387	#else
388	BOTAN_UNUSED(ws);
389	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
390	#endif
391	}	1,871✔
392	}
393
394	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::mul_px_qy(const EC_AffinePoint_Data& p,	3,472✔
395	const EC_Scalar_Data& x,
396	const EC_AffinePoint_Data& q,
397	const EC_Scalar_Data& y,
398	RandomNumberGenerator& rng) const {
399	if(m_pcurve) {	3,472✔
400	auto pt = m_pcurve->mul_px_qy(EC_AffinePoint_Data_PC::checked_ref(p).value(),	6,384✔
401	EC_Scalar_Data_PC::checked_ref(x).value(),	3,192✔
402	EC_AffinePoint_Data_PC::checked_ref(q).value(),	3,192✔
403	EC_Scalar_Data_PC::checked_ref(y).value(),	3,192✔
404	rng);	3,192✔
405
406	if(pt) {	3,192✔
407	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), m_pcurve->point_to_affine(*pt));	3,024✔
408	} else {
409	return nullptr;	168✔
410	}
411	} else {	3,192✔
412	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
413	std::vector<BigInt> ws;	280✔
414	const auto& group = p.group();	280✔
415
416	// TODO this could be better!
417	EC_Point_Var_Point_Precompute p_mul(p.to_legacy_point(), rng, ws);	280✔
418	EC_Point_Var_Point_Precompute q_mul(q.to_legacy_point(), rng, ws);	280✔
419
420	const auto order = group->order() * group->cofactor(); // See #3800	280✔
421
422	auto px = p_mul.mul(EC_Scalar_Data_BN::checked_ref(x).value(), rng, order, ws);	280✔
423	auto qy = q_mul.mul(EC_Scalar_Data_BN::checked_ref(y).value(), rng, order, ws);	280✔
424
425	auto px_qy = px + qy;	280✔
426
427	if(!px_qy.is_zero()) {	532✔
428	px_qy.force_affine();	252✔
429	return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(px_qy));	252✔
430	} else {
431	return nullptr;	28✔
432	}
433	#else
434	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
435	#endif
436	}	840✔
437	}
438
439	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::affine_add(const EC_AffinePoint_Data& p,	7,753✔
440	const EC_AffinePoint_Data& q) const {
441	if(m_pcurve) {	7,753✔
442	auto pt = m_pcurve->point_add(EC_AffinePoint_Data_PC::checked_ref(p).value(),	7,013✔
443	EC_AffinePoint_Data_PC::checked_ref(q).value());	7,013✔
444
445	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), m_pcurve->point_to_affine(pt));	7,012✔
446	} else {	7,012✔
447	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
448	auto pt = p.to_legacy_point() + q.to_legacy_point();	740✔
449	return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));	740✔
450	#else
451	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
452	#endif
453	}	740✔
454	}
455
456	std::unique_ptr<EC_AffinePoint_Data> EC_Group_Data::affine_neg(const EC_AffinePoint_Data& p) const {	9,512✔
457	if(m_pcurve) {	9,512✔
458	auto pt = m_pcurve->point_negate(EC_AffinePoint_Data_PC::checked_ref(p).value());	8,454✔
459	return std::make_unique<EC_AffinePoint_Data_PC>(shared_from_this(), pt);	8,454✔
460	} else {	8,454✔
461	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
462	auto pt = p.to_legacy_point();	1,058✔
463	pt.negate(); // negates in place	1,058✔
464	return std::make_unique<EC_AffinePoint_Data_BN>(shared_from_this(), std::move(pt));	1,058✔
465	#else
466	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
467	#endif
468	}	1,058✔
469	}
470
471	std::unique_ptr<EC_Mul2Table_Data> EC_Group_Data::make_mul2_table(const EC_AffinePoint_Data& h) const {	13,256✔
472	if(m_pcurve) {	13,256✔
473	return std::make_unique<EC_Mul2Table_Data_PC>(h);	12,956✔
474	} else {
475	#if defined(BOTAN_HAS_LEGACY_EC_POINT)
476	EC_AffinePoint_Data_BN g(shared_from_this(), this->base_point());	600✔
477	return std::make_unique<EC_Mul2Table_Data_BN>(g, h);	300✔
478	#else
479	throw Not_Implemented("Legacy EC interfaces disabled in this build configuration");
480	#endif
481	}	300✔
482	}
483
484	} // namespace Botan

randombit / botan / 13471882073

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