Expose wallet exist as rpc command

diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 8239aa0..0737205 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -185,6 +185,24 @@ namespace
         entry.suggested_confirmations_threshold = std::max(entry.suggested_confirmations_threshold, (unlock_time - now + DIFFICULTY_TARGET_V2 - 1) / DIFFICULTY_TARGET_V2);
     }
   }
+  //------------------------------------------------------------------------------------------------------------------------------
+  bool is_valid_wallet_filename(const std::string &filename, epee::json_rpc::error& er)
+  {
+    const char *ptr = strchr(filename.c_str(), '/');
+#ifdef _WIN32
+    if (!ptr)
+      ptr = strchr(filename.c_str(), '\\');
+    if (!ptr)
+      ptr = strchr(filename.c_str(), ':');
+#endif
+    if (ptr)
+    {
+      er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
+      er.message = "Invalid filename";
+      return false;
+    }
+    return true;
+  }
 }
 
 namespace tools
@@ -3608,19 +3626,8 @@ namespace tools
 
     namespace po = boost::program_options;
     po::variables_map vm2;
-    const char *ptr = strchr(req.filename.c_str(), '/');
-#ifdef _WIN32
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), '\\');
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), ':');
-#endif
-    if (ptr)
-    {
-      er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
-      er.message = "Invalid filename";
+    if (!is_valid_wallet_filename(req.filename, er))
       return false;
-    }
     std::string wallet_file = req.filename.empty() ? "" : (m_wallet_dir + "/" + req.filename);
     {
       if (!crypto::ElectrumWords::is_valid_language(req.language))
@@ -3706,19 +3713,8 @@ namespace tools
 
     namespace po = boost::program_options;
     po::variables_map vm2;
-    const char *ptr = strchr(req.filename.c_str(), '/');
-#ifdef _WIN32
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), '\\');
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), ':');
-#endif
-    if (ptr)
-    {
-      er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
-      er.message = "Invalid filename";
+    if (!is_valid_wallet_filename(req.filename, er))
       return false;
-    }
     if (m_wallet && req.autosave_current)
     {
       try
@@ -3764,6 +3760,33 @@ namespace tools
     return true;
   }
   //------------------------------------------------------------------------------------------------------------------------------
+  bool wallet_rpc_server::on_wallet_exists(const wallet_rpc::COMMAND_RPC_WALLET_EXISTS::request& req, wallet_rpc::COMMAND_RPC_WALLET_EXISTS::response& res, epee::json_rpc::error& er, const connection_context *ctx)
+  {
+    if (m_restricted)
+    {
+      er.code = WALLET_RPC_ERROR_CODE_DENIED;
+      er.message = "Command unavailable in restricted mode.";
+      return false;
+    }
+    if (m_wallet_dir.empty())
+    {
+      er.code = WALLET_RPC_ERROR_CODE_NO_WALLET_DIR;
+      er.message = "No wallet dir configured.";
+      return false;
+    }
+    if (!tools::wallet2::wallet_valid_path_format(req.filename))
+    {
+      er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
+      er.message = "Filename is required.";
+      return false;
+    }
+    if (!is_valid_wallet_filename(req.filename, er))
+      return false;
+    std::string wallet_file = m_wallet_dir + "/" + req.filename;
+    tools::wallet2::wallet_exists(wallet_file, res.keys_file_exists, res.wallet_file_exists);
+    return true;
+  }
+  //------------------------------------------------------------------------------------------------------------------------------
   bool wallet_rpc_server::on_close_wallet(const wallet_rpc::COMMAND_RPC_CLOSE_WALLET::request& req, wallet_rpc::COMMAND_RPC_CLOSE_WALLET::response& res, epee::json_rpc::error& er, const connection_context *ctx)
   {
     if (m_restricted)
@@ -3932,19 +3955,8 @@ namespace tools
 
     namespace po = boost::program_options;
     po::variables_map vm2;
-    const char *ptr = strchr(req.filename.c_str(), '/');
-  #ifdef _WIN32
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), '\\');
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), ':');
-  #endif
-    if (ptr)
-    {
-      er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
-      er.message = "Invalid filename";
+    if (!is_valid_wallet_filename(req.filename, er))
       return false;
-    }
     std::string wallet_file = req.filename.empty() ? "" : (m_wallet_dir + "/" + req.filename);
     // check if wallet file already exists
     if (!wallet_file.empty())
@@ -4122,19 +4134,8 @@ namespace tools
 
     namespace po = boost::program_options;
     po::variables_map vm2;
-    const char *ptr = strchr(req.filename.c_str(), '/');
-  #ifdef _WIN32
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), '\\');
-    if (!ptr)
-      ptr = strchr(req.filename.c_str(), ':');
-  #endif
-    if (ptr)
-    {
-      er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
-      er.message = "Invalid filename";
+    if (!is_valid_wallet_filename(req.filename, er))
       return false;
-    }
     std::string wallet_file = req.filename.empty() ? "" : (m_wallet_dir + "/" + req.filename);
     // check if wallet file already exists
     if (!wallet_file.empty())
diff --git a/src/wallet/wallet_rpc_server.h b/src/wallet/wallet_rpc_server.h
index 5e87d54..fc427c9 100644
--- a/src/wallet/wallet_rpc_server.h
+++ b/src/wallet/wallet_rpc_server.h
@@ -143,6 +143,7 @@ namespace tools
         MAP_JON_RPC_WE("get_languages",      on_get_languages,      wallet_rpc::COMMAND_RPC_GET_LANGUAGES)
         MAP_JON_RPC_WE("create_wallet",      on_create_wallet,      wallet_rpc::COMMAND_RPC_CREATE_WALLET)
         MAP_JON_RPC_WE("open_wallet",        on_open_wallet,        wallet_rpc::COMMAND_RPC_OPEN_WALLET)
+        MAP_JON_RPC_WE("wallet_exists",      on_wallet_exists,      wallet_rpc::COMMAND_RPC_WALLET_EXISTS)
         MAP_JON_RPC_WE("close_wallet",       on_close_wallet,       wallet_rpc::COMMAND_RPC_CLOSE_WALLET)
         MAP_JON_RPC_WE("change_wallet_password",        on_change_wallet_password,        wallet_rpc::COMMAND_RPC_CHANGE_WALLET_PASSWORD)
         MAP_JON_RPC_WE("generate_from_keys", on_generate_from_keys, wallet_rpc::COMMAND_RPC_GENERATE_FROM_KEYS)
@@ -239,6 +240,7 @@ namespace tools
       bool on_get_languages(const wallet_rpc::COMMAND_RPC_GET_LANGUAGES::request& req, wallet_rpc::COMMAND_RPC_GET_LANGUAGES::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
       bool on_create_wallet(const wallet_rpc::COMMAND_RPC_CREATE_WALLET::request& req, wallet_rpc::COMMAND_RPC_CREATE_WALLET::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
       bool on_open_wallet(const wallet_rpc::COMMAND_RPC_OPEN_WALLET::request& req, wallet_rpc::COMMAND_RPC_OPEN_WALLET::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
+      bool on_wallet_exists(const wallet_rpc::COMMAND_RPC_WALLET_EXISTS::request& req, wallet_rpc::COMMAND_RPC_WALLET_EXISTS::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
       bool on_close_wallet(const wallet_rpc::COMMAND_RPC_CLOSE_WALLET::request& req, wallet_rpc::COMMAND_RPC_CLOSE_WALLET::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
       bool on_change_wallet_password(const wallet_rpc::COMMAND_RPC_CHANGE_WALLET_PASSWORD::request& req, wallet_rpc::COMMAND_RPC_CHANGE_WALLET_PASSWORD::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
       bool on_generate_from_keys(const wallet_rpc::COMMAND_RPC_GENERATE_FROM_KEYS::request& req, wallet_rpc::COMMAND_RPC_GENERATE_FROM_KEYS::response& res, epee::json_rpc::error& er, const connection_context *ctx = NULL);
diff --git a/src/wallet/wallet_rpc_server_commands_defs.h b/src/wallet/wallet_rpc_server_commands_defs.h
index 8a80dc2..c281ed2 100644
--- a/src/wallet/wallet_rpc_server_commands_defs.h
+++ b/src/wallet/wallet_rpc_server_commands_defs.h
@@ -47,7 +47,7 @@
 // advance which version they will stop working with
 // Don't go over 32767 for any of these
 #define WALLET_RPC_VERSION_MAJOR 1
-#define WALLET_RPC_VERSION_MINOR 33
+#define WALLET_RPC_VERSION_MINOR 34
 #define MAKE_WALLET_RPC_VERSION(major,minor) (((major)<<16)|(minor))
 #define WALLET_RPC_VERSION MAKE_WALLET_RPC_VERSION(WALLET_RPC_VERSION_MAJOR, WALLET_RPC_VERSION_MINOR)
 namespace tools
@@ -2235,6 +2235,31 @@ namespace wallet_rpc
     typedef epee::misc_utils::struct_init<response_t> response;
   };
 
+  struct COMMAND_RPC_WALLET_EXISTS
+  {
+    struct request_t
+    {
+      std::string filename;
+
+      BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE(filename)
+      END_KV_SERIALIZE_MAP()
+    };
+    typedef epee::misc_utils::struct_init<request_t> request;
+
+    struct response_t
+    {
+      bool keys_file_exists;
+      bool wallet_file_exists;
+
+      BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE(keys_file_exists)
+        KV_SERIALIZE(wallet_file_exists)
+      END_KV_SERIALIZE_MAP()
+    };
+    typedef epee::misc_utils::struct_init<response_t> response;
+  };
+
   struct COMMAND_RPC_CLOSE_WALLET
   {
     struct request_t
diff --git a/tests/functional_tests/wallet.py b/tests/functional_tests/wallet.py
index e38cf70..f26733e 100755
--- a/tests/functional_tests/wallet.py
+++ b/tests/functional_tests/wallet.py
@@ -49,6 +49,7 @@ class WalletTest():
       self.update_lookahead()
       self.attributes()
       self.open_close()
+      self.wallet_exists()
       self.languages()
       self.change_password()
       self.store()
@@ -300,6 +301,37 @@ class WalletTest():
         res = wallet.get_address()
         assert res.address == '42ey1afDFnn4886T7196doS9GPMzexD9gXpsZJDwVjeRVdFCSoHnv7KPbBeGpzJBzHRCAs9UxqeoyFQMYbqSWYTfJJQAWDm'
 
+    def wallet_exists(self):
+        print('Testing wallet_exists')
+        wallet = Wallet()
+
+        try: wallet.close_wallet()
+        except: pass
+
+        util_resources.remove_wallet_files('test1')
+
+        res = wallet.wallet_exists('test1')
+        assert not res.keys_file_exists
+        assert not res.wallet_file_exists
+
+        seed = 'velvet lymph giddy number token physics poetry unquoted nibs useful sabotage limits benches lifestyle eden nitrogen anvil fewest avoid batch vials washing fences goat unquoted'
+        res = wallet.restore_deterministic_wallet(seed = seed, filename = 'test1')
+        assert res.address == '42ey1afDFnn4886T7196doS9GPMzexD9gXpsZJDwVjeRVdFCSoHnv7KPbBeGpzJBzHRCAs9UxqeoyFQMYbqSWYTfJJQAWDm'
+        assert res.seed == seed
+
+        util_resources.remove_file('test1')
+        res = wallet.wallet_exists('test1')
+        assert res.keys_file_exists
+        assert not res.wallet_file_exists
+
+        wallet.store()
+        res = wallet.wallet_exists('test1')
+        assert res.keys_file_exists
+        assert res.wallet_file_exists
+
+        wallet.close_wallet()
+        util_resources.remove_wallet_files('test1')
+
     def languages(self):
         print('Testing languages')
         wallet = Wallet()
diff --git a/utils/python-rpc/framework/wallet.py b/utils/python-rpc/framework/wallet.py
index 7f493d9..1fa75b5 100644
--- a/utils/python-rpc/framework/wallet.py
+++ b/utils/python-rpc/framework/wallet.py
@@ -360,6 +360,17 @@ class Wallet(object):
         }
         return self.rpc.send_json_rpc_request(open_wallet)
 
+    def wallet_exists(self, filename):
+        wallet_exists = {
+            'method': 'wallet_exists',
+            'params' : {
+                'filename': filename,
+            },
+            'jsonrpc': '2.0',
+            'id': '0'
+        }
+        return self.rpc.send_json_rpc_request(wallet_exists)
+
     def close_wallet(self, autosave_current = True):
         close_wallet = {
             'method': 'close_wallet',