addSignatureLtv method

Future<CPDFSignatureLtvResult> addSignatureLtv(String outputPath, CPDFSignatureLtvOptions options)

Adds LTV material to the signed document and writes it to outputPath.

The native SDK reads the document's saved file, collects the signer certificate chain and OCSP / CRL evidence over the network, and appends them as an incremental update. The current document is not modified or reloaded. When CPDFSignatureLtvOptions.appendDocumentTimestamp is true, a document timestamp is appended to a second copy at CPDFSignatureLtvOptions.timestampOutputPath.

A native run that cannot complete, for example because the certificate chain is untrusted or a responder is unreachable, returns a result whose CPDFSignatureLtvResult.success is false and whose CPDFSignatureLtvResult.errors explain why. Invalid arguments throw ArgumentError; an unusable document throws PlatformException.

example:

final result = await document.addSignatureLtv(
  '/path/to/signed_ltv.pdf',
  const CPDFSignatureLtvOptions(
    trustedCertificatePath: '/path/to/root.pem',
  ),
);
if (result.success) {
  await document.open(result.finalPath);
}

Since 3.2.0.

Implementation

Future<CPDFSignatureLtvResult> addSignatureLtv(
  String outputPath,
  CPDFSignatureLtvOptions options,
) async {
  if (outputPath.isEmpty) {
    throw ArgumentError.value(
      outputPath,
      'outputPath',
      'An output path is required.',
    );
  }
  if (options.trustedCertificatePath.isEmpty) {
    throw ArgumentError.value(
      options.trustedCertificatePath,
      'options.trustedCertificatePath',
      'A trusted certificate path is required.',
    );
  }
  if (options.appendDocumentTimestamp) {
    final timestampServerUrl = options.timestampServerUrl;
    if (timestampServerUrl == null ||
        !_isTimestampServerUrl(timestampServerUrl)) {
      throw ArgumentError.value(
        timestampServerUrl,
        'options.timestampServerUrl',
        'An http or https timestamp server URL is required.',
      );
    }
    final timestampOutputPath = options.timestampOutputPath;
    if (timestampOutputPath == null ||
        timestampOutputPath.isEmpty ||
        timestampOutputPath == outputPath) {
      throw ArgumentError.value(
        timestampOutputPath,
        'options.timestampOutputPath',
        'A timestamp output path different from outputPath is required.',
      );
    }
  }
  final rawResult = await _channel.invokeMethod<Map<Object?, Object?>>(
    'add_signature_ltv',
    <String, dynamic>{
      'output_path': outputPath,
      'options': options.toJson(),
    },
  );
  if (rawResult == null) {
    throw StateError('Adding LTV material returned no result.');
  }
  return CPDFSignatureLtvResult.fromJson(
    Map<String, dynamic>.from(rawResult),
  );
}