Merge pull request #34 from tewinget/master

Add electrum-seed wallet backup/recovery

.gitignore

@@ -1,3 +1,7 @@
 .DS_Store
 /build
 /tags
+
+# vim swap files
+*.swp
+*.swo

src/common/command_line.cpp

@@ -3,9 +3,21 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "command_line.h"
+#include "string_tools.h"
 
 namespace command_line
 {
+  std::string input_line(const std::string& prompt)
+  {
+    std::cout << prompt;
+
+    std::string buf;
+    std::getline(std::cin, buf);
+
+    return epee::string_tools::trim(buf);
+
+  }
+
   const arg_descriptor<bool> arg_help = {"help", "Produce help message"};
   const arg_descriptor<bool> arg_version = {"version", "Output version information"};
   const arg_descriptor<std::string> arg_data_dir = {"data-dir", "Specify data directory"};

src/common/command_line.h

@@ -14,6 +14,9 @@
 
 namespace command_line
 {
+
+  std::string input_line(const std::string& prompt);
+
   template<typename T, bool required = false>
   struct arg_descriptor;
 

src/common/pod-class.h

@@ -4,8 +4,14 @@
 
 #pragma once
 
+// FIXME: Why is this ifdef needed?  Hopefully making it struct won't break things.
+
+/*
 #if defined(_MSC_VER)
 #define POD_CLASS struct
 #else
 #define POD_CLASS class
 #endif
+*/
+
+#define POD_CLASS struct

src/crypto/crypto.cpp

@@ -50,6 +50,7 @@ namespace crypto {
     return &reinterpret_cast<const unsigned char &>(scalar);
   }
 
+  /* generate a random 32-byte (256-bit) integer and copy it to res */
   static inline void random_scalar(ec_scalar &res) {
     unsigned char tmp[64];
     generate_random_bytes(64, tmp);
@@ -62,12 +63,32 @@ namespace crypto {
     sc_reduce32(&res);
   }
 
-  void crypto_ops::generate_keys(public_key &pub, secret_key &sec) {
+  /* 
+   * generate public and secret keys from a random 256-bit integer
+   * TODO: allow specifiying random value (for wallet recovery)
+   * 
+   */
+  secret_key crypto_ops::generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key, bool recover) {
     lock_guard<mutex> lock(random_lock);
     ge_p3 point;
-    random_scalar(sec);
+
+    secret_key rng;
+
+    if (recover)
+    {
+      rng = recovery_key;
+    }
+    else
+    {
+      random_scalar(rng);
+    }
+    sec = rng;
+    sc_reduce32(&sec);  // reduce in case second round of keys (sendkeys)
+
     ge_scalarmult_base(&point, &sec);
     ge_p3_tobytes(&pub, &point);
+
+    return rng;
   }
 
   bool crypto_ops::check_key(const public_key &key) {

src/crypto/crypto.h

@@ -62,8 +62,8 @@ namespace crypto {
     void operator=(const crypto_ops &);
     ~crypto_ops();
 
-    static void generate_keys(public_key &, secret_key &);
-    friend void generate_keys(public_key &, secret_key &);
+    static secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key = secret_key(), bool recover = false);
+    friend secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key, bool recover);
     static bool check_key(const public_key &);
     friend bool check_key(const public_key &);
     static bool secret_key_to_public_key(const secret_key &, public_key &);
@@ -102,8 +102,8 @@ namespace crypto {
 
   /* Generate a new key pair
    */
-  inline void generate_keys(public_key &pub, secret_key &sec) {
-    crypto_ops::generate_keys(pub, sec);
+  inline secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key = secret_key(), bool recover = false) {
+    return crypto_ops::generate_keys(pub, sec, recovery_key, recover);
   }
 
   /* Check a public key. Returns true if it is valid, false otherwise.

src/crypto/electrum-words.cpp

@@ -0,0 +1,110 @@
+/*
+ * This file and its header file are for translating Electrum-style word lists
+ * into their equivalent byte representations for cross-compatibility with
+ * that method of "backing up" one's wallet keys.
+ */
+
+#include <string>
+#include <cassert>
+#include <map>
+#include <cstdint>
+#include <vector>
+#include <boost/algorithm/string.hpp>
+#include "crypto/crypto.h"  // for declaration of crypto::secret_key
+
+#include "crypto/electrum-words.h"
+
+namespace crypto
+{
+  namespace ElectrumWords
+  {
+
+    /* convert words to bytes, 3 words -> 4 bytes
+     * returns:
+     *    false if not a multiple of 3 words, or if a words is not in the
+     *    words list
+     *
+     *    true otherwise
+     */
+    bool words_to_bytes(const std::string& words, crypto::secret_key& dst)
+    {
+      int n = NUMWORDS; // hardcoded because this is what electrum uses
+
+      std::vector<std::string> wlist;
+
+      boost::split(wlist, words, boost::is_any_of(" "));
+
+      // error on non-compliant word list
+      if (wlist.size() != 12 && wlist.size() != 24) return false;
+
+      for (unsigned int i=0; i < wlist.size() / 3; i++)
+      {
+        uint32_t val;
+        uint32_t w1, w2, w3;
+
+        // verify all three words exist in the word list
+        if (wordsMap.count(wlist[i*3]) == 0 ||
+            wordsMap.count(wlist[i*3 + 1]) == 0 ||
+            wordsMap.count(wlist[i*3 + 2]) == 0)
+        {
+          return false;
+        }
+
+        w1 = wordsMap.at(wlist[i*3]);
+        w2 = wordsMap.at(wlist[i*3 + 1]);
+        w3 = wordsMap.at(wlist[i*3 + 2]);
+
+        val = w1 + n * (((n - w1) + w2) % n) + n * n * (((n - w2) + w3) % n);
+
+        if (!(val % n == w1)) return false;
+
+        memcpy(dst.data + i * 4, &val, 4);  // copy 4 bytes to position
+      }
+
+      std::string wlist_copy = words;
+      if (wlist.size() == 12)
+      {
+        memcpy(dst.data, dst.data + 16, 16);  // if electrum 12-word seed, duplicate
+        wlist_copy += ' ';
+        wlist_copy += words;
+      }
+
+      return true;
+    }
+
+    /* convert bytes to words, 4 bytes-> 3 words
+     * returns:
+     *    false if wrong number of bytes (shouldn't be possible)
+     *    true otherwise
+     */
+    bool bytes_to_words(const crypto::secret_key& src, std::string& words)
+    {
+      int n = NUMWORDS; // hardcoded because this is what electrum uses
+
+      if (sizeof(src.data) % 4 != 0) return false;
+
+      // 8 bytes -> 3 words.  8 digits base 16 -> 3 digits base 1626
+      for (unsigned int i=0; i < sizeof(src.data)/4; i++, words += ' ')
+      {
+        uint32_t w1, w2, w3;
+        
+        uint32_t val;
+
+        memcpy(&val, (src.data) + (i * 4), 4);
+
+        w1 = val % n;
+        w2 = ((val / n) + w1) % n;
+        w3 = (((val / n) / n) + w2) % n;
+
+        words += wordsArray[w1];
+        words += ' ';
+        words += wordsArray[w2];
+        words += ' ';
+        words += wordsArray[w3];
+      }
+      return false;
+    }
+
+  }  // namespace ElectrumWords
+
+}  // namespace crypto

src/cryptonote_core/account.cpp

@@ -10,6 +10,10 @@
 #include "account.h"
 #include "warnings.h"
 #include "crypto/crypto.h"
+extern "C"
+{
+#include "crypto/blake256.h"
+}
 #include "cryptonote_core/cryptonote_basic_impl.h"
 #include "cryptonote_core/cryptonote_format_utils.h"
 using namespace std;
@@ -29,11 +33,17 @@ DISABLE_VS_WARNINGS(4244 4345)
     m_keys = account_keys();
   }
   //-----------------------------------------------------------------
-  void account_base::generate()
+  crypto::secret_key account_base::generate(const crypto::secret_key& recovery_key, bool recover, bool two_random)
   {
-    generate_keys(m_keys.m_account_address.m_spend_public_key, m_keys.m_spend_secret_key);
-    generate_keys(m_keys.m_account_address.m_view_public_key, m_keys.m_view_secret_key);
+    crypto::secret_key first = generate_keys(m_keys.m_account_address.m_spend_public_key, m_keys.m_spend_secret_key, recovery_key, recover);
+
+    // rng for generating second set of keys is hash of first rng.  means only one set of electrum-style words needed for recovery
+    crypto::secret_key second;
+    blake256_hash((uint8_t *)&second, (uint8_t *)&first, sizeof(crypto::secret_key));
+
+    generate_keys(m_keys.m_account_address.m_view_public_key, m_keys.m_view_secret_key, second, two_random ? false : true);
     m_creation_timestamp = time(NULL);
+    return first;
   }
   //-----------------------------------------------------------------
   const account_keys& account_base::get_keys() const

src/cryptonote_core/account.h

@@ -31,7 +31,7 @@ namespace cryptonote
   {
   public:
     account_base();
-    void generate();
+    crypto::secret_key generate(const crypto::secret_key& recovery_key = crypto::secret_key(), bool recover = false, bool two_random = false);
     const account_keys& get_keys() const;
     std::string get_public_address_str();
 

src/simplewallet/simplewallet.cpp

@@ -17,6 +17,8 @@
 #include "rpc/core_rpc_server_commands_defs.h"
 #include "wallet/wallet_rpc_server.h"
 #include "version.h"
+#include "crypto/crypto.h"  // for crypto::secret_key definition
+#include "crypto/electrum-words.h"
 
 #if defined(WIN32)
 #include <crtdbg.h>
@@ -38,6 +40,9 @@ namespace
   const command_line::arg_descriptor<std::string> arg_daemon_address = {"daemon-address", "Use daemon instance at <host>:<port>", ""};
   const command_line::arg_descriptor<std::string> arg_daemon_host = {"daemon-host", "Use daemon instance at host <arg> instead of localhost", ""};
   const command_line::arg_descriptor<std::string> arg_password = {"password", "Wallet password", "", true};
+  const command_line::arg_descriptor<std::string> arg_electrum_seed = {"electrum-seed", "Specify electrum seed for wallet recovery/creation", ""};
+  const command_line::arg_descriptor<bool> arg_restore_deterministic_wallet = {"restore-deterministic-wallet", "Recover wallet using electrum-style mnemonic", false};
+  const command_line::arg_descriptor<bool> arg_non_deterministic = {"non-deterministic", "requires --generate-new-wallet, uses old generation method", false};
   const command_line::arg_descriptor<int> arg_daemon_port = {"daemon-port", "Use daemon instance at port <arg> instead of 8081", 0};
   const command_line::arg_descriptor<uint32_t> arg_log_level = {"set_log", "", 0, true};
 
@@ -208,17 +213,25 @@ bool simple_wallet::ask_wallet_create_if_needed()
 {
   std::string wallet_path;
 
-  std::cout << "Specify wallet file name (e.g., wallet.bin). If the wallet doesn't exist, it will be created.\n";
-  std::cout << "Wallet file name: ";
-
-  std::getline(std::cin, wallet_path);
-
-  wallet_path = string_tools::trim(wallet_path);
+  wallet_path = command_line::input_line(
+      "Specify wallet file name (e.g., wallet.bin). If the wallet doesn't exist, it will be created.\n"
+      "Wallet file name: "
+  );
 
   bool keys_file_exists;
   bool wallet_file_exists;
   tools::wallet2::wallet_exists(wallet_path, keys_file_exists, wallet_file_exists);
 
+  // add logic to error out if new wallet requested but named wallet file exists
+  if (keys_file_exists || wallet_file_exists)
+  {
+    if (!m_generate_new.empty() || m_restore_deterministic_wallet)
+    {
+      fail_msg_writer() << "Attempting to generate or restore wallet, but specified file(s) exist.  Exiting to not risk overwriting.";
+      return false;
+    }
+  }
+
   bool r;
   if(keys_file_exists)
   {
@@ -251,14 +264,15 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
     return false;
   }
 
-  size_t c = 0;
-  if(!m_generate_new.empty()) ++c;
-  if(!m_wallet_file.empty()) ++c;
-  if (1 != c)
+  if(!m_generate_new.empty() && !m_wallet_file.empty())
   {
-    if(!ask_wallet_create_if_needed())
+    fail_msg_writer() << "Specifying both --generate-new-wallet=\"wallet_name\" and --wallet-file=\"wallet_name\" doesn't make sense!";
     return false;
   }
+  else if (m_generate_new.empty() && m_wallet_file.empty())
+  {
+    if(!ask_wallet_create_if_needed()) return false;
+  }
 
   if (m_daemon_host.empty())
     m_daemon_host = "localhost";
@@ -282,9 +296,36 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
     }
   }
 
-  if (!m_generate_new.empty())
+  if (!m_generate_new.empty() || m_restore_deterministic_wallet)
   {
-    bool r = new_wallet(m_generate_new, pwd_container.password());
+    if (m_wallet_file.empty()) m_wallet_file = m_generate_new;  // alias for simplicity later
+
+    // check for recover flag.  if present, require electrum word list (only recovery option for now).
+    if (m_restore_deterministic_wallet)
+    {
+      if (m_non_deterministic)
+      {
+        fail_msg_writer() << "Cannot specify both --restore-deterministic-wallet and --non-deterministic";
+        return false;
+      }
+
+      if (m_electrum_seed.empty())
+      {
+        m_electrum_seed = command_line::input_line("Specify electrum seed: ");
+        if (m_electrum_seed.empty())
+        {
+          fail_msg_writer() << "specify a recovery parameter with the --electrum-seed=\"words list here\"";
+          return false;
+        }
+      }
+
+      if (!crypto::ElectrumWords::words_to_bytes(m_electrum_seed, m_recovery_key))
+      {
+          fail_msg_writer() << "electrum-style word list failed verification";
+          return false;
+      }
+    }
+    bool r = new_wallet(m_wallet_file, pwd_container.password(), m_recovery_key, m_restore_deterministic_wallet, m_non_deterministic);
     CHECK_AND_ASSERT_MES(r, false, "account creation failed");
   }
   else
@@ -311,6 +352,9 @@ void simple_wallet::handle_command_line(const boost::program_options::variables_
   m_daemon_address                = command_line::get_arg(vm, arg_daemon_address);
   m_daemon_host                   = command_line::get_arg(vm, arg_daemon_host);
   m_daemon_port                   = command_line::get_arg(vm, arg_daemon_port);
+  m_electrum_seed                 = command_line::get_arg(vm, arg_electrum_seed);
+  m_restore_deterministic_wallet  = command_line::get_arg(vm, arg_restore_deterministic_wallet);
+  m_non_deterministic             = command_line::get_arg(vm, arg_non_deterministic);
 }
 //----------------------------------------------------------------------------------------------------
 bool simple_wallet::try_connect_to_daemon()
@@ -324,16 +368,19 @@ bool simple_wallet::try_connect_to_daemon()
   }
   return true;
 }
+
 //----------------------------------------------------------------------------------------------------
-bool simple_wallet::new_wallet(const string &wallet_file, const std::string& password)
+bool simple_wallet::new_wallet(const string &wallet_file, const std::string& password, const crypto::secret_key& recovery_key, bool recover, bool two_random)
 {
   m_wallet_file = wallet_file;
 
   m_wallet.reset(new tools::wallet2());
   m_wallet->callback(this);
+
+  crypto::secret_key recovery_val;
   try
   {
-    m_wallet->generate(wallet_file, password);
+    recovery_val = m_wallet->generate(wallet_file, password, recovery_key, recover, two_random);
     message_writer(epee::log_space::console_color_white, true) << "Generated new wallet: " << m_wallet->get_account().get_public_address_str() << std::endl << "view key: " << string_tools::pod_to_hex(m_wallet->get_account().get_keys().m_view_secret_key);
   }
   catch (const std::exception& e)
@@ -344,6 +391,19 @@ bool simple_wallet::new_wallet(const string &wallet_file, const std::string& pas
 
   m_wallet->init(m_daemon_address);
 
+  // convert rng value to electrum-style word list
+  std::string electrum_words;
+  crypto::ElectrumWords::bytes_to_words(recovery_val, electrum_words);
+
+  std::string print_electrum = "";
+
+  if (!two_random)
+  {
+    print_electrum = "\nYour wallet can be recovered using the following electrum-style word list:\n";
+    print_electrum += electrum_words;
+    print_electrum += "\n";
+  }
+
   success_msg_writer() <<
     "**********************************************************************\n" <<
     "Your wallet has been generated.\n" <<
@@ -352,6 +412,7 @@ bool simple_wallet::new_wallet(const string &wallet_file, const std::string& pas
     "Always use \"exit\" command when closing simplewallet to save\n" <<
     "current session's state. Otherwise, you will possibly need to synchronize \n" <<
     "your wallet again. Your wallet key is NOT under risk anyway.\n" <<
+    print_electrum << 
     "**********************************************************************";
   return true;
 }
@@ -916,6 +977,9 @@ int main(int argc, char* argv[])
   command_line::add_arg(desc_params, arg_daemon_port);
   command_line::add_arg(desc_params, arg_command);
   command_line::add_arg(desc_params, arg_log_level);
+  command_line::add_arg(desc_params, arg_restore_deterministic_wallet );
+  command_line::add_arg(desc_params, arg_non_deterministic );
+  command_line::add_arg(desc_params, arg_electrum_seed );
   tools::wallet_rpc_server::init_options(desc_params);
 
   po::positional_options_description positional_options;

src/simplewallet/simplewallet.h

@@ -13,6 +13,7 @@
 #include "wallet/wallet2.h"
 #include "console_handler.h"
 #include "password_container.h"
+#include "crypto/crypto.h"  // for definition of crypto::secret_key
 
 
 namespace cryptonote
@@ -39,7 +40,7 @@ namespace cryptonote
 
     bool run_console_handler();
 
-    bool new_wallet(const std::string &wallet_file, const std::string& password);
+    bool new_wallet(const std::string &wallet_file, const std::string& password, const crypto::secret_key& recovery_key = crypto::secret_key(), bool recover = false, bool two_random = false);
     bool open_wallet(const std::string &wallet_file, const std::string& password);
     bool close_wallet();
 
@@ -125,6 +126,12 @@ namespace cryptonote
     std::string m_generate_new;
     std::string m_import_path;
 
+    std::string m_electrum_seed;  // electrum-style seed parameter
+
+    crypto::secret_key m_recovery_key;  // recovery key (used as random for wallet gen)
+    bool m_restore_deterministic_wallet;  // recover flag
+    bool m_non_deterministic;  // old 2-random generation
+
     std::string m_daemon_address;
     std::string m_daemon_host;
     int m_daemon_port;

src/wallet/wallet2.cpp

@@ -38,6 +38,7 @@ void do_prepare_file_names(const std::string& file_path, std::string& keys_file,
     keys_file += ".keys";
   }
 }
+
 } //namespace
 
 namespace tools
@@ -435,7 +436,7 @@ void wallet2::load_keys(const std::string& keys_file_name, const std::string& pa
   THROW_WALLET_EXCEPTION_IF(!r, error::invalid_password);
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::generate(const std::string& wallet_, const std::string& password)
+crypto::secret_key wallet2::generate(const std::string& wallet_, const std::string& password, const crypto::secret_key& recovery_param, bool recover, bool two_random)
 {
   clear();
   prepare_file_names(wallet_);
@@ -444,7 +445,8 @@ void wallet2::generate(const std::string& wallet_, const std::string& password)
   THROW_WALLET_EXCEPTION_IF(boost::filesystem::exists(m_wallet_file, ignored_ec), error::file_exists, m_wallet_file);
   THROW_WALLET_EXCEPTION_IF(boost::filesystem::exists(m_keys_file,   ignored_ec), error::file_exists, m_keys_file);
 
-  m_account.generate();
+  crypto::secret_key retval = m_account.generate(recovery_param, recover, two_random);
+
   m_account_public_address = m_account.get_keys().m_account_address;
 
   bool r = store_keys(m_keys_file, password);
@@ -454,6 +456,7 @@ void wallet2::generate(const std::string& wallet_, const std::string& password)
   if(!r) LOG_PRINT_RED_L0("String with address text not saved");
 
   store();
+  return retval;
 }
 //----------------------------------------------------------------------------------------------------
 void wallet2::wallet_exists(const std::string& file_path, bool& keys_file_exists, bool& wallet_file_exists)

src/wallet/wallet2.h

@@ -97,7 +97,7 @@ namespace tools
       END_SERIALIZE()
     };
 
-    void generate(const std::string& wallet, const std::string& password);
+    crypto::secret_key generate(const std::string& wallet, const std::string& password, const crypto::secret_key& recovery_param = crypto::secret_key(), bool recover = false, bool two_random = false);
     void load(const std::string& wallet, const std::string& password);
     void store();
     cryptonote::account_base& get_account(){return m_account;}
@@ -227,6 +227,7 @@ namespace boost
 
 namespace tools
 {
+
   namespace detail
   {
     //----------------------------------------------------------------------------------------------------

src/wallet/wallet_errors.h

@@ -188,6 +188,17 @@ namespace tools
 
       std::string to_string() const { return wallet_logic_error::to_string(); }
     };
+
+    //----------------------------------------------------------------------------------------------------
+    struct invalid_pregenerated_random : public wallet_logic_error
+    {
+      explicit invalid_pregenerated_random (std::string&& loc)
+        : wallet_logic_error(std::move(loc), "invalid pregenerated random for wallet creation/recovery")
+      {
+      }
+
+      std::string to_string() const { return wallet_logic_error::to_string(); }
+    };
     //----------------------------------------------------------------------------------------------------
     struct refresh_error : public wallet_logic_error
     {