1 files changed, 155 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/pubkey/ecgdsa/ecgdsa.cpp b/comm/third_party/botan/src/lib/pubkey/ecgdsa/ecgdsa.cpp
new file mode 100644
index 0000000000..7ed8763158
--- /dev/null
+++ b/comm/third_party/botan/src/lib/pubkey/ecgdsa/ecgdsa.cpp
@@ -0,0 +1,155 @@
+/*
+* ECGDSA (BSI-TR-03111, version 2.0)
+* (C) 2016 René Korthaus
+* (C) 2018 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/ecgdsa.h>
+#include <botan/keypair.h>
+#include <botan/reducer.h>
+#include <botan/internal/pk_ops_impl.h>
+#include <botan/internal/point_mul.h>
+
+namespace Botan {
+
+bool ECGDSA_PrivateKey::check_key(RandomNumberGenerator& rng,
+                                 bool strong) const
+   {
+   if(!public_point().on_the_curve())
+      return false;
+
+   if(!strong)
+      return true;
+
+   return KeyPair::signature_consistency_check(rng, *this, "EMSA1(SHA-256)");
+   }
+
+namespace {
+
+/**
+* ECGDSA signature operation
+*/
+class ECGDSA_Signature_Operation final : public PK_Ops::Signature_with_EMSA
+   {
+   public:
+
+      ECGDSA_Signature_Operation(const ECGDSA_PrivateKey& ecgdsa,
+                                const std::string& emsa) :
+         PK_Ops::Signature_with_EMSA(emsa),
+         m_group(ecgdsa.domain()),
+         m_x(ecgdsa.private_value())
+         {
+         }
+
+      secure_vector<uint8_t> raw_sign(const uint8_t msg[], size_t msg_len,
+                                      RandomNumberGenerator& rng) override;
+
+      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(); }
+
+   private:
+      const EC_Group m_group;
+      const BigInt& m_x;
+      std::vector<BigInt> m_ws;
+   };
+
+secure_vector<uint8_t>
+ECGDSA_Signature_Operation::raw_sign(const uint8_t msg[], size_t msg_len,
+                                     RandomNumberGenerator& rng)
+   {
+   const BigInt m(msg, msg_len, m_group.get_order_bits());
+
+   const BigInt k = m_group.random_scalar(rng);
+
+   const BigInt r = m_group.mod_order(
+      m_group.blinded_base_point_multiply_x(k, rng, m_ws));
+
+   const BigInt kr = m_group.multiply_mod_order(k, r);
+
+   const BigInt s = m_group.multiply_mod_order(m_x, kr - m);
+
+   // With overwhelming probability, a bug rather than actual zero r/s
+   if(r.is_zero() || s.is_zero())
+      throw Internal_Error("During ECGDSA signature generated zero r/s");
+
+   return BigInt::encode_fixed_length_int_pair(r, s, m_group.get_order_bytes());
+   }
+
+/**
+* ECGDSA verification operation
+*/
+class ECGDSA_Verification_Operation final : public PK_Ops::Verification_with_EMSA
+   {
+   public:
+
+      ECGDSA_Verification_Operation(const ECGDSA_PublicKey& ecgdsa,
+                                   const std::string& emsa) :
+         PK_Ops::Verification_with_EMSA(emsa),
+         m_group(ecgdsa.domain()),
+         m_gy_mul(m_group.get_base_point(), ecgdsa.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 ECGDSA_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 e(msg, msg_len, m_group.get_order_bits());
+
+   const BigInt r(sig, sig_len / 2);
+   const BigInt s(sig + sig_len / 2, sig_len / 2);
+
+   if(r <= 0 || r >= m_group.get_order() || s <= 0 || s >= m_group.get_order())
+      return false;
+
+   const BigInt w = m_group.inverse_mod_order(r);
+
+   const BigInt u1 = m_group.multiply_mod_order(e, w);
+   const BigInt u2 = m_group.multiply_mod_order(s, w);
+   const PointGFp R = m_gy_mul.multi_exp(u1, u2);
+
+   if(R.is_zero())
+      return false;
+
+   const BigInt v = m_group.mod_order(R.get_affine_x());
+   return (v == r);
+   }
+
+}
+
+std::unique_ptr<PK_Ops::Verification>
+ECGDSA_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 ECGDSA_Verification_Operation(*this, params));
+   throw Provider_Not_Found(algo_name(), provider);
+   }
+
+std::unique_ptr<PK_Ops::Signature>
+ECGDSA_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 ECGDSA_Signature_Operation(*this, params));
+   throw Provider_Not_Found(algo_name(), provider);
+   }
+
+}