====== Security Guidelines ======

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

<note warning>These guidelines are **non-negotiable**. Code that violates them will not be accepted.</note>

===== OWASP Top 10 Prevention =====

==== CWE-78: Command Injection ====

**Risk:** Execution of arbitrary commands through manipulated input.

<code pascal>
// 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);
</code>

**Measures:**
  * Always use ''shell: false''
  * Pass arguments as array
  * Validate paths before use

==== CWE-22: Path Traversal ====

**Risk:** Access to files outside the allowed directory.

<code pascal>
// 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));
</code>

**Measures:**
  * Block ''..'' sequences
  * Normalize and validate paths
  * Base path must be prefix of result path

==== CWE-20: Input Validation ====

**Risk:** Invalid data leads to malfunction or attack.

<code pascal>
// 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;
</code>

==== CWE-316: Cleartext Credentials ====

**Risk:** Credentials in code or logs.

<code pascal>
// 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)]);
</code>

==== CWE-532: Log Injection ====

**Risk:** Sensitive data visible in logs.

<code pascal>
// 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)]);
</code>

==== CWE-79: Cross-Site Scripting (XSS) ====

**Risk:** Injection of script code into WebViews.

<code pascal>
// 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>';
</code>

==== CWE-20: WebView Message Whitelist ====

**Risk:** Unknown message types enable attacks on WebView handlers.

<note warning>Every WebView message handler MUST implement a whitelist of allowed message types.</note>

<code pascal>
// 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;
</code>

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

==== Defensive Node.js API Calls ====

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

<note>Practical problem: ''stdout.setEncoding'' is not a function when process is not correctly initialized.</note>

<code pascal>
// 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;
</code>

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

===== Error Handling =====

==== No Empty Exception Handlers ====

<code pascal>
// 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;
</code>

==== Specific Exception Types ====

<code pascal>
// 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;
</code>

===== Debug Logging =====

Debug logging requires **two conditions**:

  - **Compile-time:** ''{$IFDEF DEBUG}''
  - **Runtime:** ''--debug'' parameter

<code pascal>
{$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}
</code>

==== What May Be Logged ====

^ Allowed ^ Forbidden ^
| Filenames, paths | Tokens, API keys |
| Action names | Passwords |
| Numeric IDs | Session IDs |
| Error messages | Full requests/responses |
| Configuration keys | Configuration values (sensitive) |

===== Secure Defaults =====

<code pascal>
// 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;
</code>

===== Code Review Checklist =====

Before merge MUST be checked:

<code>
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)
</code>

===== Security Audit ====

Regular checking with automated tools:

==== wvds-lint Security Checks ====

<code bash>
wvds-lint security --path sources/
</code>

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

==== Manual Review ====

For every new extension:
  * Check all entry points
  * Trace all external inputs
  * Review WebView communication

===== Incident Response =====

When a security vulnerability is discovered:

  - **Do not publish** until patch is ready
  - Issue on GitHub with label "security" (private)
  - Develop and test patch
  - Release new version
  - Publish advisory

===== See Also =====

  * [[.:code-konventionen|Code Conventions]]
  * [[.:debugging|Debugging]]
  * [[.:testing|Testing]]
  * [[https://owasp.org/www-project-top-ten/|OWASP Top 10]]