fetchCertificate method

Future<String> fetchCertificate(
  1. String host, {
  2. int port = 443,
})

Fetches the TLS leaf certificate from a host as a PEM string.

Opens an ephemeral side-channel TLS connection, performs OS-level chain validation, extracts the leaf certificate, and immediately cancels the connection without sending any HTTP data.

Example Usage

try {
  final pem = await TrustPin.shared.fetchCertificate('api.example.com');
  await TrustPin.shared.verify('api.example.com', pem);
  print('Certificate is valid!');
} on TrustPinException catch (e) {
  print('Failed: $e');
}

  • Parameter host: Hostname to connect to (e.g. "api.example.com").

  • Parameter port: TCP port (default: 443).

  • Returns: PEM-encoded leaf certificate string.

  • Throws TrustPinException with code INVALID_SERVER_CERT if the TLS handshake fails.

Implementation

Future<String> fetchCertificate(String host, {int port = 443}) async {
  try {
    return await TrustPinSDKPlatform.instance
        .fetchCertificate(host, port: port, instanceId: _instanceId);
  } catch (e) {
    throw TrustPinException.fromPlatformException(e);
  }
}