refactor: use int value for leaked byte without encoding

backend/src/main.cpp

@@ -57,7 +57,8 @@ int main(int argc, char *argv[])
     if (build)
     {
         // create all tables from 0 to (2^8)^offset-1
-        for (int i = 0; i < std::pow(std::pow(2, 8), offset); i++)
+        const int num_tables = std::pow(std::pow(2, 8), offset);
+        for (int i = 0; i < num_tables; i++)
         {
             db.execute("CREATE TABLE `" + std::to_string(i) + "` (password TEXT);");
         }
@@ -78,11 +79,10 @@ int main(int argc, char *argv[])
         for (const auto &password : encrypted_passwords)
         {
             // determine which table to insert into based on leaked byte
-            std::string encoded_byte = crow::utility::base64encode(password.substr(0, offset), offset);
-            std::string table_num = std::to_string(static_cast<unsigned int>(encoded_byte[0]));
+            unsigned int leaked_byte = ((unsigned char)password.substr(0, offset)[0]) & (num_tables-1);
             std::string raw_password = password.substr(offset, password.size() - offset);
             // encode password before inserting into database
-            db.execute("INSERT INTO `" + table_num + "` (password) VALUES ('" + crow::utility::base64encode(raw_password, raw_password.size()) + "');");
+            db.execute("INSERT INTO `" + std::to_string(leaked_byte) + "` (password) VALUES ('" + crow::utility::base64encode(raw_password, raw_password.size()) + "');");
         }
 
         // create key table

backend/src/server.cpp

@@ -34,11 +34,11 @@ namespace server
 
         // get the table num corresponding to the user password leaked byte
         std::string decoded_password = crow::utility::base64decode(user_password, user_password.size());
-        std::string encoded_leaked_byte = crow::utility::base64encode(decoded_password.substr(0, offset), offset);
-        std::string table_num = std::to_string(static_cast<unsigned int>(encoded_leaked_byte[0]));
+        unsigned char leaked_byte = decoded_password.substr(0, offset)[0];
+        unsigned int table_num = leaked_byte & ((int)std::pow(std::pow(2, 8), offset) - 1);
 
         // get all passwords from the table corresponding to the user password leaked byte
-        std::vector<std::string> breached_passwords = db.execute("SELECT * FROM `" + table_num + "`;", callback);
+        std::vector<std::string> breached_passwords = db.execute("SELECT * FROM `" + std::to_string(table_num) + "`;", callback);
 
         // get b secret key from database
         std::string encoded_b = db.execute("SELECT * FROM secret;", callback)[0];

backend/tests/server.cpp

@@ -30,9 +30,10 @@ TEST_CASE("Test endpoints using handler")
 
     // offset constant
     const size_t offset = 1;
+    const int num_tables = std::pow(std::pow(2, 8), offset);
 
     // create all tables from 0 to (2^8)^offset-1
-    for (int i = 0; i < std::pow(std::pow(2, 8), offset); i++)
+    for (int i = 0; i < num_tables; i++)
     {
         db.execute("CREATE TABLE `" + std::to_string(i) + "` (password TEXT);");
     }
@@ -51,13 +52,11 @@ TEST_CASE("Test endpoints using handler")
     for (const auto &password : encrypted_passwords)
     {
         // determine which table to insert into based on leaked byte
-        std::string encoded_byte = crow::utility::base64encode(password.substr(0, offset), offset);
-        std::string table_num = std::to_string(static_cast<unsigned int>(encoded_byte[0]));
-
+        unsigned int leaked_byte = ((unsigned char)password.substr(0, offset)[0]) & (num_tables-1);
         std::string raw_password = password.substr(offset, password.size() - offset);
 
         // encode password before inserting into database
-        db.execute("INSERT INTO `" + table_num + "` (password) VALUES ('" + crow::utility::base64encode(raw_password, raw_password.size()) + "');");
+        db.execute("INSERT INTO `" + std::to_string(leaked_byte) + "` (password) VALUES ('" + crow::utility::base64encode(raw_password, raw_password.size()) + "');");
     }
 
     // create key table