text: //------------------------------------------------------------------------------
  /*
      This file is part of jbcoind: https://github.com/jbcoin/jbcoind
      Copyright (c) 2012, 2013 JBCoin Labs Inc.
  
      Permission to use, copy, modify, and/or distribute this software for any
      purpose  with  or without fee is hereby granted, provided that the above
      copyright notice and this permission notice appear in all copies.
  
      THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
      MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
      ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
      WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
      ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
      OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
  //==============================================================================
  
  #include <jbcoin/app/misc/Manifest.h>
  #include <jbcoin/basics/base64.h>
  #include <jbcoin/basics/contract.h>
  #include <jbcoin/basics/Log.h>
  #include <jbcoin/basics/StringUtilities.h>
  #include <jbcoin/beast/rfc2616.h>
  #include <jbcoin/core/DatabaseCon.h>
  #include <jbcoin/json/json_reader.h>
  #include <jbcoin/protocol/PublicKey.h>
  #include <jbcoin/protocol/Sign.h>
  #include <boost/regex.hpp>
  #include <numeric>
  #include <stdexcept>
  
  namespace jbcoin {
  
  boost::optional<Manifest>
  Manifest::make_Manifest (std::string s)
  {
      try
      {
          STObject st (sfGeneric);
          SerialIter sit (s.data (), s.size ());
          st.set (sit);
          auto const pk = st.getFieldVL (sfPublicKey);
          if (! publicKeyType (makeSlice(pk)))
              return boost::none;
  
          auto const opt_seq = get (st, sfSequence);
          auto const opt_msig = get (st, sfMasterSignature);
          if (!opt_seq || !opt_msig)
              return boost::none;
  
          // Signing key and signature are not required for
          // master key revocations
          if (*opt_seq != std::numeric_limits<std::uint32_t>::max ())
          {
              auto const spk = st.getFieldVL (sfSigningPubKey);
              if (! publicKeyType (makeSlice(spk)))
                  return boost::none;
              if (! get (st, sfSignature))
                  return boost::none;
              return Manifest (std::move (s), PublicKey (makeSlice(pk)),
                  PublicKey (makeSlice(spk)), *opt_seq);
          }
  
          return Manifest (std::move (s), PublicKey (makeSlice(pk)),
              PublicKey(), *opt_seq);
      }
      catch (std::exception const&)
      {
          return boost::none;
      }
  }
  
  template<class Stream>
  Stream&
  logMftAct (
      Stream& s,
      std::string const& action,
      PublicKey const& pk,
      std::uint32_t seq)
  {
      s << "Manifest: " << action <<
           ";Pk: " << toBase58 (TokenType::NodePublic, pk) <<
           ";Seq: " << seq << ";";
      return s;
  }
  
  template<class Stream>
  Stream& logMftAct (
      Stream& s,
      std::string const& action,
      PublicKey const& pk,
      std::uint32_t seq,
      std::uint32_t oldSeq)
  {
      s << "Manifest: " << action <<
           ";Pk: " << toBase58 (TokenType::NodePublic, pk) <<
           ";Seq: " << seq <<
           ";OldSeq: " << oldSeq << ";";
      return s;
  }
  
  Manifest::Manifest (std::string s,
                      PublicKey pk,
                      PublicKey spk,
                      std::uint32_t seq)
      : serialized (std::move (s))
      , masterKey (std::move (pk))
      , signingKey (std::move (spk))
      , sequence (seq)
  {
  }
  
  bool Manifest::verify () const
  {
      STObject st (sfGeneric);
      SerialIter sit (serialized.data (), serialized.size ());
      st.set (sit);
  
      // Signing key and signature are not required for
      // master key revocations
      if (! revoked () && ! jbcoin::verify (st, HashPrefix::manifest, signingKey))
          return false;
  
      return jbcoin::verify (
          st, HashPrefix::manifest, masterKey, sfMasterSignature);
  }
  
  uint256 Manifest::hash () const
  {
      STObject st (sfGeneric);
      SerialIter sit (serialized.data (), serialized.size ());
      st.set (sit);
      return st.getHash (HashPrefix::manifest);
  }
  
  bool Manifest::revoked () const
  {
      /*
          The maximum possible sequence number means that the master key
          has been revoked.
      */
      return sequence == std::numeric_limits<std::uint32_t>::max ();
  }
  
  Blob Manifest::getSignature () const
  {
      STObject st (sfGeneric);
      SerialIter sit (serialized.data (), serialized.size ());
      st.set (sit);
      return st.getFieldVL (sfSignature);
  }
  
  Blob Manifest::getMasterSignature () const
  {
      STObject st (sfGeneric);
      SerialIter sit (serialized.data (), serialized.size ());
      st.set (sit);
      return st.getFieldVL (sfMasterSignature);
  }
  
  ValidatorToken::ValidatorToken(std::string const& m, SecretKey const& valSecret)
      : manifest(m)
      , validationSecret(valSecret)
  {
  }
  
  boost::optional<ValidatorToken>
  ValidatorToken::make_ValidatorToken(std::vector<std::string> const& tokenBlob)
  {
      try
      {
          std::string tokenStr;
          tokenStr.reserve (
              std::accumulate (tokenBlob.cbegin(), tokenBlob.cend(), std::size_t(0),
                  [] (std::size_t init, std::string const& s)
                  {
                      return init + s.size();
                  }));
  
          for (auto const& line : tokenBlob)
              tokenStr += beast::rfc2616::trim(line);
  
          tokenStr = base64_decode(tokenStr);
  
          Json::Reader r;
          Json::Value token;
          if (! r.parse (tokenStr, token))
              return boost::none;
  
          if (token.isMember("manifest") && token["manifest"].isString() &&
              token.isMember("validation_secret_key") &&
              token["validation_secret_key"].isString())
          {
              auto const ret = strUnHex (token["validation_secret_key"].asString());
              if (! ret.second || ! ret.first.size ())
                  return boost::none;
  
              return ValidatorToken(
                  token["manifest"].asString(),
                  SecretKey(Slice{ret.first.data(), ret.first.size()}));
          }
          else
          {
              return boost::none;
          }
      }
      catch (std::exception const&)
      {
          return boost::none;
      }
  }
  
  PublicKey
  ManifestCache::getSigningKey (PublicKey const& pk) const
  {
      std::lock_guard<std::mutex> lock{read_mutex_};
      auto const iter = map_.find (pk);
  
      if (iter != map_.end () && !iter->second.revoked ())
          return iter->second.signingKey;
  
      return pk;
  }
  
  PublicKey
  ManifestCache::getMasterKey (PublicKey const& pk) const
  {
      std::lock_guard<std::mutex> lock{read_mutex_};
      auto const iter = signingToMasterKeys_.find (pk);
  
      if (iter != signingToMasterKeys_.end ())
          return iter->second;
  
      return pk;
  }
  
  bool
  ManifestCache::revoked (PublicKey const& pk) const
  {
      std::lock_guard<std::mutex> lock{read_mutex_};
      auto const iter = map_.find (pk);
  
      if (iter != map_.end ())
          return iter->second.revoked ();
  
      return false;
  }
  
  ManifestDisposition
  ManifestCache::applyManifest (Manifest m)
  {
      std::lock_guard<std::mutex> applyLock{apply_mutex_};
  
      /*
          before we spend time checking the signature, make sure the
          sequence number is newer than any we have.
      */
      auto const iter = map_.find(m.masterKey);
  
      if (iter != map_.end() &&
          m.sequence <= iter->second.sequence)
      {
          /*
              A manifest was received for a validator we're tracking, but
              its sequence number is not higher than the one already stored.
              This will happen normally when a peer without the latest gossip
              connects.
          */
          if (auto stream = j_.debug())
              logMftAct(stream, "Stale", m.masterKey, m.sequence, iter->second.sequence);
          return ManifestDisposition::stale;  // not a newer manifest, ignore
      }
  
      if (! m.verify())
      {
          /*
            A manifest's signature is invalid.
            This shouldn't happen normally.
          */
          if (auto stream = j_.warn())
              logMftAct(stream, "Invalid", m.masterKey, m.sequence);
          return ManifestDisposition::invalid;
      }
  
      std::lock_guard<std::mutex> readLock{read_mutex_};
  
      bool const revoked = m.revoked();
  
      if (iter == map_.end ())
      {
          /*
              This is the first received manifest for a trusted master key
              (possibly our own).  This only happens once per validator per
              run.
          */
          if (auto stream = j_.info())
              logMftAct(stream, "AcceptedNew", m.masterKey, m.sequence);
  
          if (! revoked)
              signingToMasterKeys_[m.signingKey] = m.masterKey;
  
          map_.emplace (std::make_pair(m.masterKey, std::move (m)));
      }
      else
      {
          /*
              An ephemeral key was revoked and superseded by a new key.
              This is expected, but should happen infrequently.
          */
          if (auto stream = j_.info())
              logMftAct(stream, "AcceptedUpdate",
                        m.masterKey, m.sequence, iter->second.sequence);
  
          signingToMasterKeys_.erase (iter->second.signingKey);
  
          if (! revoked)
              signingToMasterKeys_[m.signingKey] = m.masterKey;
  
          iter->second = std::move (m);
      }
  
      if (revoked)
      {
          /*
              A validator master key has been compromised, so its manifests
              are now untrustworthy.  In order to prevent us from accepting
              a forged manifest signed by the compromised master key, store
              this manifest, which has the highest possible sequence number
              and therefore can't be superseded by a forged one.
          */
          if (auto stream = j_.warn())
              logMftAct(stream, "Revoked", m.masterKey, m.sequence);
      }
  
      return ManifestDisposition::accepted;
  }
  
  void
  ManifestCache::load (
      DatabaseCon& dbCon, std::string const& dbTable)
  {
      // Load manifests stored in database
      std::string const sql =
          "SELECT RawData FROM " + dbTable + ";";
      auto db = dbCon.checkoutDb ();
      soci::blob sociRawData (*db);
      soci::statement st =
          (db->prepare << sql,
               soci::into (sociRawData));
      st.execute ();
      while (st.fetch ())
      {
          std::string serialized;
          convert (sociRawData, serialized);
          if (auto mo = Manifest::make_Manifest (std::move (serialized)))
          {
              if (!mo->verify())
              {
                  JLOG(j_.warn())
                      << "Unverifiable manifest in db";
                  continue;
              }
  
              applyManifest (std::move(*mo));
          }
          else
          {
              JLOG(j_.warn())
                  << "Malformed manifest in database";
          }
      }
  }
  
  bool
  ManifestCache::load (
      DatabaseCon& dbCon, std::string const& dbTable,
      std::string const& configManifest,
      std::vector<std::string> const& configRevocation)
  {
      load (dbCon, dbTable);
  
      if (! configManifest.empty())
      {
          auto mo = Manifest::make_Manifest (
              base64_decode(configManifest));
          if (! mo)
          {
              JLOG (j_.error()) << "Malformed validator_token in config";
              return false;
          }
  
          if (mo->revoked())
          {
              JLOG (j_.warn()) <<
                  "Configured manifest revokes public key";
          }
  
          if (applyManifest (std::move(*mo)) ==
              ManifestDisposition::invalid)
          {
              JLOG (j_.error()) << "Manifest in config was rejected";
              return false;
          }
      }
  
      if (! configRevocation.empty())
      {
          std::string revocationStr;
          revocationStr.reserve (
              std::accumulate (configRevocation.cbegin(), configRevocation.cend(), std::size_t(0),
                  [] (std::size_t init, std::string const& s)
                  {
                      return init + s.size();
                  }));
  
          for (auto const& line : configRevocation)
              revocationStr += beast::rfc2616::trim(line);
  
          auto mo = Manifest::make_Manifest (
              base64_decode(revocationStr));
  
          if (! mo || ! mo->revoked() ||
              applyManifest (std::move(*mo)) == ManifestDisposition::invalid)
          {
              JLOG (j_.error()) << "Invalid validator key revocation in config";
              return false;
          }
      }
  
      return true;
  }
  
  void ManifestCache::save (
      DatabaseCon& dbCon, std::string const& dbTable,
      std::function <bool (PublicKey const&)> isTrusted)
  {
      std::lock_guard<std::mutex> lock{apply_mutex_};
  
      auto db = dbCon.checkoutDb ();
  
      soci::transaction tr(*db);
      *db << "DELETE FROM " << dbTable;
      std::string const sql =
          "INSERT INTO " + dbTable + " (RawData) VALUES (:rawData);";
      for (auto const& v : map_)
      {
          // Save all revocation manifests,
          // but only save trusted non-revocation manifests.
          if (! v.second.revoked() && ! isTrusted (v.second.masterKey))
          {
  
              JLOG(j_.info())
                 << "Untrusted manifest in cache not saved to db";
              continue;
          }
  
          // soci does not support bulk insertion of blob data
          // Do not reuse blob because manifest ecdsa signatures vary in length
          // but blob write length is expected to be >= the last write
          soci::blob rawData(*db);
          convert (v.second.serialized, rawData);
          *db << sql,
              soci::use (rawData);
      }
      tr.commit ();
  }
  }
  