elliptic_em.hpp

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#pragma once
#include <fc/crypto/bigint.hpp>
#include <fc/crypto/common.hpp>
#include <fc/crypto/openssl.hpp>
#include <fc/crypto/sha256.hpp>
#include <fc/crypto/sha512.hpp>
#include <fc/crypto/keccak256.hpp>
#include <fc/fwd.hpp>
#include <fc/array.hpp>
#include <fc/io/raw_fwd.hpp>
#include <fc/crypto/elliptic.hpp>
 
namespace fc {
 
  namespace em {
    namespace detail
    {
      class public_key_impl;
      class private_key_impl;
    }
 
    typedef fc::sha256                  blind_factor_type;
    typedef fc::array<char,33>          commitment_type;
    typedef fc::array<char,33>          public_key_data;
    typedef fc::sha256                  private_key_secret;
    typedef fc::array<char,65>          public_key_point_data; 
    typedef fc::array<char,72>          signature;
    typedef fc::array<unsigned char,65> compact_signature;
    typedef fc::array<char,78>          extended_key_data;
    typedef fc::sha256                  blinded_hash;
    typedef fc::sha256                  blind_signature;
 
    class public_key
    {
        public:
           public_key();
           public_key(const public_key& k);
           ~public_key();
//           bool verify( const fc::sha256& digest, const signature& sig );
           public_key_data serialize()const;
           public_key_point_data serialize_ecc_point()const;
 
           operator public_key_data()const { return serialize(); }
 
 
           public_key( const public_key_data& v );
           public_key( const public_key_point_data& v );
           public_key( const compact_signature& c, const fc::sha256& digest, bool check_canonical = true );
           public_key( const compact_signature& c, const unsigned char* digest, bool check_canonical = true );
 
           public_key child( const fc::sha256& offset )const;
 
           bool valid()const;
 
           public_key( public_key&& pk );
           public_key& operator=( public_key&& pk );
           public_key& operator=( const public_key& pk );
 
           inline friend bool operator==( const public_key& a, const public_key& b )
           {
            return a.serialize() == b.serialize();
           }
           inline friend bool operator!=( const public_key& a, const public_key& b )
           {
            return a.serialize() != b.serialize();
           }
 
           std::string to_base58() const;
           static std::string to_base58( const public_key_data &key );
           static public_key from_base58( const std::string& b58 );
 
           unsigned int fingerprint() const;
 
        private:
          friend class private_key;
          static public_key from_key_data( const public_key_data& v );
          static bool is_canonical( const compact_signature& c );
          fc::fwd<detail::public_key_impl,33> my;
    };
 
    class private_key
    {
        public:
           private_key();
           private_key( private_key&& pk );
           private_key( const private_key& pk );
           ~private_key();
 
           private_key& operator=( private_key&& pk );
           private_key& operator=( const private_key& pk );
 
           static private_key generate();
           static private_key regenerate( const fc::sha256& secret );
 
           private_key child( const fc::sha256& offset )const;
 
           static private_key generate_from_seed( const fc::sha256& seed, const fc::sha256& offset = fc::sha256() );
 
           private_key_secret get_secret()const; // get the private key secret
 
           operator private_key_secret ()const { return get_secret(); }
 
           fc::sha512 get_shared_secret( const public_key& pub )const;
 
//           signature         sign( const fc::sha256& digest )const;
           compact_signature sign_compact( const fc::sha256& digest, bool require_canonical = true )const;
//           bool              verify( const fc::sha256& digest, const signature& sig );
 
           public_key get_public_key()const;
 
           inline friend bool operator==( const private_key& a, const private_key& b )
           {
            return a.get_secret() == b.get_secret();
           }
           inline friend bool operator!=( const private_key& a, const private_key& b )
           {
            return a.get_secret() != b.get_secret();
           }
           inline friend bool operator<( const private_key& a, const private_key& b )
           {
            return a.get_secret() < b.get_secret();
           }
 
           unsigned int fingerprint() const { return get_public_key().fingerprint(); }
 
        private:
           private_key( EC_KEY* k );
           static fc::sha256 get_secret( const EC_KEY * const k );
           fc::fwd<detail::private_key_impl,32> my;
    };
 
      struct public_key_shim : public crypto::shim<public_key_data> {
         using crypto::shim<public_key_data>::shim;
 
         bool valid()const {
            return public_key(_data).valid();
         }
      };
 
      struct signature_shim : public crypto::shim<compact_signature> {
         using public_key_type = public_key_shim;
         using crypto::shim<compact_signature>::shim;
 
         public_key_type recover(const sha256& digest, bool check_canonical) const {
            // "x19Ethereum Signed Message:\n" is the header used by the `eth_sign` RPC call. We have converted the string to its hex value to save a step.
            // std::string erc155_message_prefix = "19457468657265756d205369676e6564204d6573736167653a0a3332";
            uint8_t eth_prefix[28] = {
               25,  69, 116, 104, 101, 114, 101,
               117, 109,  32,  83, 105, 103, 110,
               101, 100,  32,  77, 101, 115, 115,
               97, 103, 101,  58,  10,  51,  50
            };
            // Hash (keccak256) the msg string
 
            // unsigned char msg_digest_result = digest.data();
            unsigned char eth_prefixed_msg_raw[28 + 32];
            std::copy(std::begin(eth_prefix), std::end(eth_prefix), std::begin(eth_prefixed_msg_raw));
            std::copy((unsigned char*) digest.data(), (unsigned char*) digest.data() + 32, std::begin(eth_prefixed_msg_raw) + 28);
 
            SHA3_CTX msg_ctx;
            keccak_init(&msg_ctx);
            keccak_update(&msg_ctx, eth_prefixed_msg_raw, 60);
            
            // Hash the newly created raw message.
            unsigned char msg_digest_result[32];
            keccak_final(&msg_ctx, msg_digest_result);
 
            // sha256 msg_digest 
            return public_key_type(public_key(_data, msg_digest_result, false).serialize());
         }
      };
 
      struct private_key_shim : public crypto::shim<private_key_secret> {
         using crypto::shim<private_key_secret>::shim;
         using signature_type = signature_shim;
         using public_key_type = public_key_shim;
 
         signature_type sign( const sha256& digest, bool require_canonical = true ) const
         {
           return signature_type(private_key::regenerate(_data).sign_compact(digest, require_canonical));
         }
 
         public_key_type get_public_key( ) const
         {
           return public_key_type(private_key::regenerate(_data).get_public_key().serialize());
         }
 
         sha512 generate_shared_secret( const public_key_type &pub_key ) const
         {
           return private_key::regenerate(_data).get_shared_secret(public_key(pub_key.serialize()));
         }
 
         static private_key_shim generate()
         {
            return private_key_shim(private_key::generate().get_secret());
         }
 
      };
 
  } // namespace ecc
  void to_variant( const em::private_key& var,  variant& vo );
  void from_variant( const variant& var,  em::private_key& vo );
  void to_variant( const em::public_key& var,  variant& vo );
  void from_variant( const variant& var,  em::public_key& vo );
 
  namespace raw
  {
      template<typename Stream>
      void unpack( Stream& s, fc::em::public_key& pk)
      {
          em::public_key_data ser;
          fc::raw::unpack(s,ser);
          pk = fc::em::public_key( ser );
      }
 
      template<typename Stream>
      void pack( Stream& s, const fc::em::public_key& pk)
      {
          fc::raw::pack( s, pk.serialize() );
      }
 
      template<typename Stream>
      void unpack( Stream& s, fc::em::private_key& pk)
      {
          fc::sha256 sec;
          unpack( s, sec );
          pk = em::private_key::regenerate(sec);
      }
 
      template<typename Stream>
      void pack( Stream& s, const fc::em::private_key& pk)
      {
          fc::raw::pack( s, pk.get_secret() );
      }
 
  } // namespace raw
 
} // namespace fc
#include <fc/reflect/reflect.hpp>
 
FC_REFLECT_TYPENAME( fc::em::private_key )
FC_REFLECT_TYPENAME( fc::em::public_key )
FC_REFLECT_DERIVED( fc::em::public_key_shim, (fc::crypto::shim<fc::em::public_key_data>), BOOST_PP_SEQ_NIL )
FC_REFLECT_DERIVED( fc::em::signature_shim, (fc::crypto::shim<fc::em::compact_signature>), BOOST_PP_SEQ_NIL )
FC_REFLECT_DERIVED( fc::em::private_key_shim, (fc::crypto::shim<fc::em::private_key_secret>), BOOST_PP_SEQ_NIL )