monero/src/multisig/multisig.h

// Copyright (c) 2017-2018, The Monero Project
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#pragma once

#include <vector>
#include <unordered_map>
#include "crypto/crypto.h"
#include "cryptonote_basic/cryptonote_format_utils.h"
#include "ringct/rctTypes.h"

namespace cryptonote
{
  struct account_keys;

  crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key);
  void generate_multisig_N_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey);
  void generate_multisig_N1_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey);
  /**
   * @brief generate_multisig_derivations performs common DH key derivation.
   *    Each middle round in M/N scheme is DH exchange of public multisig keys of other participants multiplied by secret spend key of current participant.
   *    this functions does the following: new multisig key = secret spend * public multisig key
   * @param keys - current wallet's keys
   * @param derivations - public multisig keys of other participants
   * @return new public multisig keys derived from previous round. This data needs to be exchange with other participants
   */
  std::vector<crypto::public_key> generate_multisig_derivations(const account_keys &keys, const std::vector<crypto::public_key> &derivations);
  crypto::secret_key calculate_multisig_signer_key(const std::vector<crypto::secret_key>& derivations);
  /**
   * @brief calculate_multisig_keys. Calculates secret multisig keys from others' participants ones as follows: mi = H(Mi)
   * @param derivations - others' participants public multisig keys.
   * @return vector of current wallet's multisig secret keys
   */
  std::vector<crypto::secret_key> calculate_multisig_keys(const std::vector<crypto::public_key>& derivations);
  crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector<crypto::secret_key> &skeys);
  /**
   * @brief generate_multisig_M_N_spend_public_key calculates multisig wallet's spend public key by summing all of public multisig keys
   * @param pkeys unique public multisig keys
   * @return multisig wallet's spend public key
   */
  crypto::public_key generate_multisig_M_N_spend_public_key(const std::vector<crypto::public_key> &pkeys);
  bool generate_multisig_key_image(const account_keys &keys, size_t multisig_key_index, const crypto::public_key& out_key, crypto::key_image& ki);
  void generate_multisig_LR(const crypto::public_key pkey, const crypto::secret_key &k, crypto::public_key &L, crypto::public_key &R);
  bool generate_multisig_composite_key_image(const account_keys &keys, const std::unordered_map<crypto::public_key, cryptonote::subaddress_index>& subaddresses, const crypto::public_key& out_key, const crypto::public_key &tx_public_key, const std::vector<crypto::public_key>& additional_tx_public_keys, size_t real_output_index, const std::vector<crypto::key_image> &pkis, crypto::key_image &ki);
  uint32_t multisig_rounds_required(uint32_t participants, uint32_t threshold);
}