Determine wallet file type based on file magic

1 files changed, 25 insertions, 1 deletions

diff --git a/src/wallet/sqlite.cpp b/src/wallet/sqlite.cpp
index 5c30d72e84..ce390440d9 100644
--- a/src/wallet/sqlite.cpp
+++ b/src/wallet/sqlite.cpp
@@ -502,7 +502,8 @@ bool SQLiteBatch::TxnAbort()
 
 bool ExistsSQLiteDatabase(const fs::path& path)
 {
-    return false;
+    const fs::path file = path / DATABASE_FILENAME;
+    return fs::symlink_status(file).type() == fs::regular_file && IsSQLiteFile(file);
 }
 
 std::unique_ptr<SQLiteDatabase> MakeSQLiteDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error)
@@ -526,3 +527,26 @@ std::string SQLiteDatabaseVersion()
 {
     return std::string(sqlite3_libversion());
 }
+
+bool IsSQLiteFile(const fs::path& path)
+{
+    if (!fs::exists(path)) return false;
+
+    // A SQLite Database file is at least 512 bytes.
+    boost::system::error_code ec;
+    auto size = fs::file_size(path, ec);
+    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
+    if (size < 512) return false;
+
+    fsbridge::ifstream file(path, std::ios::binary);
+    if (!file.is_open()) return false;
+
+    // Magic is at beginning and is 16 bytes long
+    char magic[16];
+    file.read(magic, 16);
+    file.close();
+
+    // Check the magic, see https://sqlite.org/fileformat2.html
+    std::string magic_str(magic);
+    return magic_str == std::string("SQLite format 3");
+}