pfx_reader

A Flutter plugin to read PKCS#12 (.pfx / .p12) certificate fields and sign data using the embedded private key. Supports Android and iOS.

Features

  • Extract X.509 certificate fields from a PFX/PKCS#12 file:
    • Subject DN and individual fields: Common Name (CN), Organization (O), Organizational Unit (OU), Country (C), Email (E)
    • Issuer DN
    • Validity dates (notBefore, notAfter)
    • Serial number
  • Two input methods:
    • Load from raw bytes (e.g. from an asset or file picker)
    • Load from a file path on disk
  • Sign arbitrary data using the private key embedded in the PFX
  • Supported signing algorithms: SHA256withRSA (default), SHA1withRSA, SHA512withRSA
  • Typed PfxException with PfxErrorCode enum — no raw PlatformException string-matching needed

Platform support

Android iOS
✅ ✅
  • Android: uses java.security.KeyStore (PKCS12 provider) and java.security.Signature
  • iOS: uses SecPKCS12Import for import/signing, and a pure Swift ASN.1 DER parser for certificate field extraction (fully compatible with simulator and device)

Installation

Add pfx_reader to your pubspec.yaml:

dependencies:
  pfx_reader: ^1.0.0

Then run:

flutter pub get

Usage

Read certificate info from bytes

import 'package:pfx_reader/pfx_reader.dart';

final Uint8List pfxBytes = ...; // load from asset, file picker, etc.

try {
  final CertificateInfo info = await PfxReader.fromBytes(pfxBytes, 'password');

  print(info.commonName);    // e.g. "John Doe"
  print(info.organization);  // e.g. "Acme Corp"
  print(info.notAfter);      // expiration date (UTC)
  print(info.serialNumber);  // certificate serial number
  print(info.subjectDN);     // full subject DN string
  print(info.issuerDN);      // full issuer DN string
} on PfxException catch (e) {
  print('${e.code}: ${e.message}');
}

Read certificate info from a file path

try {
  final CertificateInfo info = await PfxReader.fromFile('/path/to/cert.pfx', 'password');
  print(info.commonName);
} on PfxException catch (e) {
  print('${e.code}: ${e.message}');
}

Sign data from bytes

final Uint8List dataToSign = ...; // the raw bytes you want to sign
final Uint8List pfxBytes   = ...; // your PFX certificate bytes

try {
  final Uint8List signature = await PfxReader.signWithBytes(
    dataToSign,
    pfxBytes,
    'password',
    algorithm: SignAlgorithm.sha256WithRSA, // optional, default is sha256WithRSA
  );
} on PfxException catch (e) {
  print('${e.code}: ${e.message}');
}

Sign data from a file path

final Uint8List signature = await PfxReader.signWithFile(
  dataToSign,
  '/path/to/cert.pfx',
  'password',
  algorithm: SignAlgorithm.sha512WithRSA,
);

API reference

PfxReader

Method Description
fromBytes(Uint8List bytes, String password) Parse certificate fields from raw PFX bytes
fromFile(String filePath, String password) Parse certificate fields from a PFX file path
signWithBytes(Uint8List data, Uint8List pfxBytes, String password, {SignAlgorithm algorithm}) Sign data using the private key from PFX bytes
signWithFile(Uint8List data, String filePath, String password, {SignAlgorithm algorithm}) Sign data using the private key from a PFX file

CertificateInfo

Field Type Description
subjectDN String Full subject Distinguished Name
issuerDN String Full issuer Distinguished Name
notBefore DateTime Certificate validity start (UTC)
notAfter DateTime Certificate validity end / expiration (UTC)
serialNumber String Serial number (decimal string)
commonName String? Common Name (CN)
organization String? Organization (O)
organizationalUnit String? Organizational Unit (OU)
country String? Country (C)
email String? Email address (E / emailAddress)

SignAlgorithm

Value Description
SignAlgorithm.sha256WithRSA SHA-256 with RSA PKCS#1 v1.5 (default)
SignAlgorithm.sha1WithRSA SHA-1 with RSA (legacy)
SignAlgorithm.sha512WithRSA SHA-512 with RSA

PfxException / PfxErrorCode

Code Description
wrongPassword Incorrect PFX password
fileNotFound File path does not exist or cannot be read
importError Corrupt or unsupported PFX format
keyError Private key could not be extracted
signError Signing operation failed
unknown Unexpected error

Libraries

pfx_reader