wallet: add command and RPC to sign/verify data

Signing is done using the spend key, since the view key may
be shared. This could be extended later, to let the user choose
which key (even a per tx key).
simplewallet's sign/verify API uses a file. The RPC uses a
string (simplewallet can't easily do strings since commands
receive a tokenized set of arguments).

2 files changed, 69 insertions, 0 deletions

diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index 4a7a70b8c..1862173b9 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -658,6 +658,8 @@ simple_wallet::simple_wallet()
   m_cmd_binder.set_handler("set_tx_note", boost::bind(&simple_wallet::set_tx_note, this, _1), tr("Set an arbitrary string note for a txid"));
   m_cmd_binder.set_handler("get_tx_note", boost::bind(&simple_wallet::get_tx_note, this, _1), tr("Get a string note for a txid"));
   m_cmd_binder.set_handler("status", boost::bind(&simple_wallet::status, this, _1), tr("Show wallet status information"));
+  m_cmd_binder.set_handler("sign", boost::bind(&simple_wallet::sign, this, _1), tr("Sign the contents of a file"));
+  m_cmd_binder.set_handler("verify", boost::bind(&simple_wallet::verify, this, _1), tr("Verify a signature on the contents of a file"));
   m_cmd_binder.set_handler("help", boost::bind(&simple_wallet::help, this, _1), tr("Show this help"));
 }
 //----------------------------------------------------------------------------------------------------
@@ -3368,6 +3370,71 @@ bool simple_wallet::status(const std::vector<std::string> &args)
   return true;
 }
 //----------------------------------------------------------------------------------------------------
+bool simple_wallet::sign(const std::vector<std::string> &args)
+{
+  if (args.size() != 1)
+  {
+    fail_msg_writer() << tr("usage: sign <filename>");
+    return true;
+  }
+  if (m_wallet->watch_only())
+  {
+    fail_msg_writer() << tr("wallet is watch-only and cannot sign");
+    return true;
+  }
+  std::string filename = args[0];
+  std::string data;
+  bool r = epee::file_io_utils::load_file_to_string(filename, data);
+  if (!r)
+  {
+    fail_msg_writer() << tr("failed to read file ") << filename;
+    return true;
+  }
+  std::string signature = m_wallet->sign(data);
+  success_msg_writer() << signature;
+  return true;
+}
+//----------------------------------------------------------------------------------------------------
+bool simple_wallet::verify(const std::vector<std::string> &args)
+{
+  if (args.size() != 3)
+  {
+    fail_msg_writer() << tr("usage: verify <filename> <address> <signature>");
+    return true;
+  }
+  std::string filename = args[0];
+  std::string address_string = args[1];
+  std::string signature= args[2];
+
+  std::string data;
+  bool r = epee::file_io_utils::load_file_to_string(filename, data);
+  if (!r)
+  {
+    fail_msg_writer() << tr("failed to read file ") << filename;
+    return true;
+  }
+
+  cryptonote::account_public_address address;
+  bool has_payment_id;
+  crypto::hash8 payment_id;
+  if(!get_account_integrated_address_from_str(address, has_payment_id, payment_id, m_wallet->testnet(), address_string))
+  {
+    fail_msg_writer() << tr("failed to parse address");
+    return true;
+  }
+
+  r = m_wallet->verify(data, address, signature);
+  if (!r)
+  {
+    fail_msg_writer() << tr("Bad signature from ") << address_string;
+  }
+  else
+  {
+    success_msg_writer() << tr("Good signature from ") << address_string;
+  }
+  return true;
+}
+//----------------------------------------------------------------------------------------------------
 bool simple_wallet::process_command(const std::vector<std::string> &args)
 {
   return m_cmd_binder.process_command_vec(args);
diff --git a/src/simplewallet/simplewallet.h b/src/simplewallet/simplewallet.h
index e0478eb6e..97f30834a 100644
--- a/src/simplewallet/simplewallet.h
+++ b/src/simplewallet/simplewallet.h
@@ -143,6 +143,8 @@ namespace cryptonote
     bool get_tx_note(const std::vector<std::string> &args);
     bool status(const std::vector<std::string> &args);
     bool set_default_fee_multiplier(const std::vector<std::string> &args);
+    bool sign(const std::vector<std::string> &args);
+    bool verify(const std::vector<std::string> &args);
 
     uint64_t get_daemon_blockchain_height(std::string& err);
     bool try_connect_to_daemon();