Add password()

include/tao/pq/connection.hpp

@@ -176,6 +176,8 @@ namespace tao::pq
       void set_timeout( const std::chrono::milliseconds timeout );
       void reset_timeout() noexcept;
 
+      [[nodiscard]] auto password( const internal::zsv passwd, const internal::zsv user, const internal::zsv algorithm = "scram-sha-256" ) -> std::string;
+
       [[nodiscard]] auto underlying_raw_ptr() noexcept -> PGconn*
       {
          return m_pgconn.get();

src/lib/pq/connection.cpp

@@ -611,4 +611,13 @@ namespace tao::pq
       m_timeout = std::nullopt;
    }
 
+   auto connection::password( const internal::zsv passwd, const internal::zsv user, const internal::zsv algorithm ) -> std::string
+   {
+      std::unique_ptr< char, decltype( &PQfreemem ) > buffer( PQencryptPasswordConn( m_pgconn.get(), passwd, user, algorithm ), &PQfreemem );
+      if( !buffer ) {
+         throw std::invalid_argument( PQerrorMessage( m_pgconn.get() ) );  // LCOV_EXCL_LINE
+      }
+      return buffer.get();
+   }
+
 }  // namespace tao::pq

src/test/pq/password.cpp

@@ -0,0 +1,50 @@
+// Copyright (c) 2024 Daniel Frey and Dr. Colin Hirsch
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
+
+#include "../getenv.hpp"
+#include "../macros.hpp"
+
+#include <exception>
+#include <format>
+#include <iostream>
+
+#include <tao/pq.hpp>
+
+namespace
+{
+   void run()
+   {
+      // overwrite the default with an environment variable if needed
+      const auto connection_string = tao::pq::internal::getenv( "TAOPQ_TEST_DATABASE", "dbname=template1" );
+
+      // open a connection to the database
+      const auto conn = tao::pq::connection::create( connection_string );
+
+      // prevent cleartext passwords from showing up in logs, traces, etc.
+      const auto cleartext_password = "secret123";
+      const auto encrypted_password = conn->password( cleartext_password, "tao_test_role" );
+
+      // execute commands
+      conn->execute( "DROP ROLE IF EXISTS tao_test_role" );
+      conn->execute( std::format( "CREATE ROLE tao_test_role PASSWORD '{}'", encrypted_password ) );
+   }
+
+}  // namespace
+
+auto main() -> int  // NOLINT(bugprone-exception-escape)
+{
+   try {
+      run();
+   }
+   // LCOV_EXCL_START
+   catch( const std::exception& e ) {
+      std::cerr << "exception: " << e.what() << '\n';
+      throw;
+   }
+   catch( ... ) {
+      std::cerr << "unknown exception\n";
+      throw;
+   }
+   // LCOV_EXCL_STOP
+}