Security Guidelines

Mandatory security standards for WvdS FPC RAD Suite, compliant with KRITIS/NIS2.

Risk: Execution of arbitrary commands through manipulated input.

// FORBIDDEN - Insecure!
Exec('cmd /c ' + UserInput);
Shell('fpc ' + ProjectPath + ' ' + UserArgs);
 
// CORRECT - Parameterized
Options.Shell := False;
Args := TStringArray.Create;
Args.Add(ProjectPath);
Spawn('fpc', Args, Options);

Measures:

• Always use shell: false
• Pass arguments as array
• Validate paths before use

Risk: Access to files outside the allowed directory.

// FORBIDDEN - Insecure!
FileName := BasePath + UserInput;
ReadFile(FileName);
 
// CORRECT - Validation
function IsPathSafe(const ABasePath, AUserInput: string): Boolean;
var
  ResolvedPath: string;
begin
  // Do not allow ..
  if Pos('..', AUserInput) > 0 then
    Exit(False);
 
  ResolvedPath := ExpandFileName(Concat(ABasePath, AUserInput));
  Result := Pos(ABasePath, ResolvedPath) = 1;
end;
 
if IsPathSafe(BasePath, UserInput) then
  ReadFile(Concat(BasePath, UserInput));

Measures:

• Block .. sequences
• Normalize and validate paths
• Base path must be prefix of result path

Risk: Invalid data leads to malfunction or attack.

// FORBIDDEN - No validation
procedure CreateProject(const AName: string);
begin
  MakeDir(AName);  // What if AName = '../../../etc'?
end;
 
// CORRECT - Validation
function ValidateProjectName(const AName: string; out AError: string): Boolean;
const
  ALLOWED_CHARS = ['a'..'z', 'A'..'Z', '0'..'9', '_', '-'];
  MAX_LENGTH = 64;
var
  I: Integer;
begin
  Result := False;
 
  if AName = '' then
  begin
    AError := rsProjectNameEmpty;
    Exit;
  end;
 
  if Length(AName) > MAX_LENGTH then
  begin
    AError := Format(rsProjectNameTooLong, [MAX_LENGTH]);
    Exit;
  end;
 
  for I := 1 to Length(AName) do
    if not (AName[I] in ALLOWED_CHARS) then
    begin
      AError := Format(rsProjectNameInvalidChar, [AName[I]]);
      Exit;
    end;
 
  Result := True;
end;

Risk: Credentials in code or logs.

// FORBIDDEN - Credentials in code
const
  API_TOKEN = 'ghp_xxxxxxxxxxxx';
  DB_PASSWORD = 'secret123';
 
// FORBIDDEN - Logging credentials
LogDebug('Token: %s', [Token]);
 
// CORRECT - Environment Variables
Token := GetEnvironmentVariable('GITHUB_TOKEN');
if Token = '' then
  raise EWvdSConfigError.Create(rsTokenNotConfigured);
 
// CORRECT - Masked logging
LogDebug('Token configured: %s', [BoolToStr(Token <> '', True)]);

Risk: Sensitive data visible in logs.

// FORBIDDEN
LogInfo('User login: %s with password: %s', [User, Password]);
LogDebug('API response: %s', [FullResponse]);  // May contain tokens!
 
// CORRECT
LogInfo('User login: %s', [User]);  // No password
LogDebug('API response received, length: %d', [Length(Response)]);

Risk: Injection of script code into WebViews.

// FORBIDDEN - Unescaped HTML
WebView.Html := '<div>' + UserInput + '</div>';
 
// CORRECT - Escaping
function EscapeHtml(const AText: string): string;
begin
  Result := AText;
  Result := StringReplace(Result, '&', '&amp;', [rfReplaceAll]);
  Result := StringReplace(Result, '<', '&lt;', [rfReplaceAll]);
  Result := StringReplace(Result, '>', '&gt;', [rfReplaceAll]);
  Result := StringReplace(Result, '"', '&quot;', [rfReplaceAll]);
  Result := StringReplace(Result, '''', '&#39;', [rfReplaceAll]);
end;
 
WebView.Html := '<div>' + EscapeHtml(UserInput) + '</div>';

Risk: Unknown message types enable attacks on WebView handlers.

// FORBIDDEN - No message type check
procedure HandleMessage(AMessage: TJSObject);
var
  MsgType: string;
begin
  MsgType := string(AMessage['type']);
  case MsgType of
    'browse': HandleBrowse(AMessage);
    'save': HandleSave(AMessage);
  end;
end;
 
// CORRECT - With whitelist
const
  ALLOWED_MESSAGE_TYPES: array[0..6] of string = (
    'browse', 'save', 'cancel', 'validatePath',
    'autoDetect', 'config', 'pathSelected'
  );
 
function IsAllowedMessageType(const AType: string): Boolean;
var
  I: Integer;
begin
  Result := False;
  for I := Low(ALLOWED_MESSAGE_TYPES) to High(ALLOWED_MESSAGE_TYPES) do
    if ALLOWED_MESSAGE_TYPES[I] = AType then
      Exit(True);
end;
 
procedure HandleMessage(AMessage: TJSObject);
var
  MsgType: string;
begin
  MsgType := string(AMessage['type']);
 
  // Whitelist check FIRST
  if not IsAllowedMessageType(MsgType) then
  begin
    LogWarning(rsUnknownMessageType, [MsgType]);
    Exit;
  end;
 
  case MsgType of
    'browse': HandleBrowse(AMessage);
    'save': HandleSave(AMessage);
    // ...
  end;
end;

Measures:

• Define whitelist with all allowed message types
• Log and reject unknown types
• Update whitelist when adding new features

Risk: Node.js APIs can have different methods depending on context.

// FORBIDDEN - Direct method calls without check
procedure SetupProcessHandlers;
begin
  asm
    this.FProcess.stdout.setEncoding('utf8');
    this.FProcess.stderr.setEncoding('utf8');
  end;
end;
 
// CORRECT - Defensive typeof checks
procedure SetupProcessHandlers;
begin
  asm
    if (this.FProcess && this.FProcess.stdout) {
      if (typeof this.FProcess.stdout.setEncoding === 'function') {
        this.FProcess.stdout.setEncoding('utf8');
      }
      if (typeof this.FProcess.stdout.on === 'function') {
        this.FProcess.stdout.on('data', this.HandleStdout.bind(this));
      }
    }
    if (this.FProcess && this.FProcess.stderr) {
      if (typeof this.FProcess.stderr.setEncoding === 'function') {
        this.FProcess.stderr.setEncoding('utf8');
      }
      if (typeof this.FProcess.stderr.on === 'function') {
        this.FProcess.stderr.on('data', this.HandleStderr.bind(this));
      }
    }
  end;
end;

Measures:

• typeof … === 'function' before every method call
• Check object existence (if (obj && obj.property))
• Handle missing APIs gracefully

// FORBIDDEN
try
  DoSomething;
except
  // Swallowing errors
end;
 
// CORRECT
try
  DoSomething;
except
  on E: ESpecificError do
  begin
    LogError(rsSpecificError, [E.Message]);
    // Handle...
  end;
  on E: Exception do
  begin
    LogError(rsUnexpectedError, [E.ClassName, E.Message]);
    raise;  // Or handle appropriately
  end;
end;

// CORRECT - Specific exceptions
try
  Result := DoOperation;
except
  on E: EFileNotFoundException do
    HandleFileNotFound(E.FileName);
  on E: EAccessDenied do
    HandleAccessDenied(E.Path);
  on E: ENetworkError do
    HandleNetworkError(E.Url);
  on E: Exception do
    HandleUnexpectedError(E);
end;

Debug logging requires two conditions:

1. Compile-time: {$IFDEF DEBUG}
2. Runtime: –debug parameter

{$IFDEF DEBUG}
var
  DebugLogFile: TextFile;
  DebugEnabled: Boolean;
 
procedure InitDebugLogging;
begin
  DebugEnabled := ParamStr(1) = '--debug';
  if DebugEnabled then
  begin
    AssignFile(DebugLogFile, Format('debug-%s.log',
      [FormatDateTime('yymmddhhnnss', Now)]));
    Rewrite(DebugLogFile);
  end;
end;
 
procedure LogDebugTrace(const AMessage: string; const AArgs: array of const);
begin
  if not DebugEnabled then Exit;
 
  WriteLn(DebugLogFile, Format('[%s] %s',
    [FormatDateTime('hh:nn:ss.zzz', Now), Format(AMessage, AArgs)]));
  Flush(DebugLogFile);
end;
{$ENDIF}

// Secure default values
const
  DEFAULT_TIMEOUT = 30000;  // 30 seconds
  MAX_FILE_SIZE = 10 * 1024 * 1024;  // 10 MB
  MAX_RECURSION_DEPTH = 100;
 
type
  TSpawnOptions = record
    Shell: Boolean;        // Default: False (secure)
    Timeout: Integer;      // Default: 30000
    WorkingDir: string;
    Environment: TStringArray;
  end;
 
function DefaultSpawnOptions: TSpawnOptions;
begin
  Result.Shell := False;  // IMPORTANT: No shell!
  Result.Timeout := DEFAULT_TIMEOUT;
  Result.WorkingDir := '';
  Result.Environment := nil;
end;

Before merge MUST be checked:

SECURITY:
[ ] No hardcoded credentials
[ ] All user inputs validated
[ ] No shell injection possible
[ ] No path traversal possible
[ ] HTML is escaped in WebViews
[ ] No sensitive data in logs

ERROR HANDLING:
[ ] No empty exception handlers
[ ] Specific exceptions handled
[ ] Errors are logged (without sensitive data)

CONFIGURATION:
[ ] Secure defaults used
[ ] Timeouts defined
[ ] Limits defined (file size, recursion)

Regular checking with automated tools:

wvds-lint security --path sources/

Checks:

• Exec/Shell calls
• Path operations without validation
• Hardcoded strings (potential credentials)
• Empty exception handlers
• Log calls with sensitive parameters

For every new extension:

• Check all entry points
• Trace all external inputs
• Review WebView communication

When a security vulnerability is discovered:

1. Do not publish until patch is ready
2. Issue on GitHub with label „security“ (private)
3. Develop and test patch
4. Release new version
5. Publish advisory

• Code Conventions
• Debugging
• Testing
• OWASP Top 10