1 files changed, 142 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/pubkey/dh/dh.cpp b/comm/third_party/botan/src/lib/pubkey/dh/dh.cpp
new file mode 100644
index 0000000000..687032a696
--- /dev/null
+++ b/comm/third_party/botan/src/lib/pubkey/dh/dh.cpp
@@ -0,0 +1,142 @@
+/*
+* Diffie-Hellman
+* (C) 1999-2007,2016,2019 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/dh.h>
+#include <botan/internal/pk_ops_impl.h>
+#include <botan/internal/monty_exp.h>
+#include <botan/blinding.h>
+
+namespace Botan {
+
+/*
+* DH_PublicKey Constructor
+*/
+DH_PublicKey::DH_PublicKey(const DL_Group& grp, const BigInt& y1)
+   {
+   m_group = grp;
+   m_y = y1;
+   }
+
+/*
+* Return the public value for key agreement
+*/
+std::vector<uint8_t> DH_PublicKey::public_value() const
+   {
+   return unlock(BigInt::encode_1363(m_y, group_p().bytes()));
+   }
+
+/*
+* Create a DH private key
+*/
+DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
+                             const DL_Group& grp,
+                             const BigInt& x_arg)
+   {
+   m_group = grp;
+
+   if(x_arg == 0)
+      {
+      const size_t exp_bits = grp.exponent_bits();
+      m_x.randomize(rng, exp_bits);
+      m_y = m_group.power_g_p(m_x, exp_bits);
+      }
+   else
+      {
+      m_x = x_arg;
+
+      if(m_y == 0)
+         m_y = m_group.power_g_p(m_x, grp.p_bits());
+      }
+   }
+
+/*
+* Load a DH private key
+*/
+DH_PrivateKey::DH_PrivateKey(const AlgorithmIdentifier& alg_id,
+                             const secure_vector<uint8_t>& key_bits) :
+   DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_42)
+   {
+   if(m_y.is_zero())
+      {
+      m_y = m_group.power_g_p(m_x, m_group.p_bits());
+      }
+   }
+
+/*
+* Return the public value for key agreement
+*/
+std::vector<uint8_t> DH_PrivateKey::public_value() const
+   {
+   return DH_PublicKey::public_value();
+   }
+
+namespace {
+
+/**
+* DH operation
+*/
+class DH_KA_Operation final : public PK_Ops::Key_Agreement_with_KDF
+   {
+   public:
+
+      DH_KA_Operation(const DH_PrivateKey& key, const std::string& kdf, RandomNumberGenerator& rng) :
+         PK_Ops::Key_Agreement_with_KDF(kdf),
+         m_p(key.group_p()),
+         m_x(key.get_x()),
+         m_x_bits(m_x.bits()),
+         m_monty_p(key.get_group().monty_params_p()),
+         m_blinder(m_p,
+                   rng,
+                   [](const BigInt& k) { return k; },
+                   [this](const BigInt& k) { return powermod_x_p(inverse_mod(k, m_p)); })
+         {}
+
+      size_t agreed_value_size() const override { return m_p.bytes(); }
+
+      secure_vector<uint8_t> raw_agree(const uint8_t w[], size_t w_len) override;
+   private:
+      BigInt powermod_x_p(const BigInt& v) const
+         {
+         const size_t powm_window = 4;
+         auto powm_v_p = monty_precompute(m_monty_p, v, powm_window);
+         return monty_execute(*powm_v_p, m_x, m_x_bits);
+         }
+
+      const BigInt& m_p;
+      const BigInt& m_x;
+      const size_t m_x_bits;
+      std::shared_ptr<const Montgomery_Params> m_monty_p;
+      Blinder m_blinder;
+   };
+
+secure_vector<uint8_t> DH_KA_Operation::raw_agree(const uint8_t w[], size_t w_len)
+   {
+   BigInt v = BigInt::decode(w, w_len);
+
+   if(v <= 1 || v >= m_p - 1)
+      throw Invalid_Argument("DH agreement - invalid key provided");
+
+   v = m_blinder.blind(v);
+   v = powermod_x_p(v);
+   v = m_blinder.unblind(v);
+
+   return BigInt::encode_1363(v, m_p.bytes());
+   }
+
+}
+
+std::unique_ptr<PK_Ops::Key_Agreement>
+DH_PrivateKey::create_key_agreement_op(RandomNumberGenerator& rng,
+                                       const std::string& params,
+                                       const std::string& provider) const
+   {
+   if(provider == "base" || provider.empty())
+      return std::unique_ptr<PK_Ops::Key_Agreement>(new DH_KA_Operation(*this, params, rng));
+   throw Provider_Not_Found(algo_name(), provider);
+   }
+
+}