Dart Requires Chilkat v11.0.0+

Verify a .p7m and get Algorithm Information

See more Digital Signatures Examples

Demonstrates how to verify a .p7m and then examine the algorithms used by the signature. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  final crypt = CkCrypt2();

  final inFile = 'qa_data/p7m/brainpoolP256r1.p7m';
  final outFile = 'qa_output/something.dat';

  // Verify and extract the signed data.
  try {
    crypt.verifyP7M(inFile, outFile);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Examine details about the signature(s)
  final json = CkJsonObject();
  crypt.getLastJsonData(json);
  json.emitCompact = false;
  print(json.emit());

  // Sample output

  // {
  //   "pkcs7": {
  //     "verify": {
  //       "digestAlgorithms": [
  //         "sha256"
  //       ],
  //       "signerInfo": [
  //         {
  //           "cert": {
  //             "serialNumber": "FFFFE552B302FFFFFF1E34C3ACEB2FFFF",
  //             "issuerCN": "The common name of the cert...",
  //             "issuerDN": "",
  //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
  //             "digestAlgName": "SHA256"
  //           },
  //           "contentType": "1.2.840.113549.1.7.1",
  //           "signingTime": "190409140500Z",
  //           "messageDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
  //           "signingAlgOid": "1.2.840.10045.4.3.2",
  //           "signerDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
  //           "authAttr": [
  //             {
  //               "oid": "1.2.840.113549.1.9.3",
  //               "oidName": "contentType"
  //             },
  //             {
  //               "oid": "1.2.840.113549.1.9.5",
  //               "oidName": "signingTime"
  //             },
  //             {
  //               "oid": "1.2.840.113549.1.9.52",
  //               "oidName": "1.2.840.113549.1.9.52",
  //               "der": "MBs ... AwI="
  //             },
  //             {
  //               "oid": "1.2.840.113549.1.9.4",
  //               "oidName": "messageDigest"
  //             },
  //             {
  //               "oid": "1.2.840.113549.1.9.16.2.47",
  //               "oidName": "signingCertificateV2",
  //               "der": "MCYw .. 7PlQ=="
  //             },
  //             {
  //               "oid": "1.2.840.113549.1.9.20",
  //               "oidName": "1.2.840.113549.1.9.20"
  //             }
  //           ]
  //         }
  //       ]
  //     }
  //   }
  // }

  // Code for parsing the above JSON...
  var i = 0;
  var countI = 0;
  var strVal = '';
  var certSerialNumber = '';
  var certIssuerCN = '';
  var certIssuerDN = '';
  var certDigestAlgOid = '';
  var certDigestAlgName = '';
  var contentType = '';
  var signingTime = '';
  var messageDigest = '';
  var signingAlgOid = '';
  var signerDigest = '';
  var j = 0;
  var countJ = 0;
  var oid = '';
  var oidName = '';
  var der = '';

  i = 0;
  countI = json.sizeOfArray('pkcs7.verify.digestAlgorithms');
  while (i < countI) {
    json.i = i;
    strVal = json.stringOf('pkcs7.verify.digestAlgorithms[i]');
    i++;
  }

  i = 0;
  countI = json.sizeOfArray('pkcs7.verify.signerInfo');
  while (i < countI) {
    json.i = i;
    certSerialNumber = json.stringOf('pkcs7.verify.signerInfo[i].cert.serialNumber');
    certIssuerCN = json.stringOf('pkcs7.verify.signerInfo[i].cert.issuerCN');
    certIssuerDN = json.stringOf('pkcs7.verify.signerInfo[i].cert.issuerDN');
    certDigestAlgOid = json.stringOf('pkcs7.verify.signerInfo[i].cert.digestAlgOid');
    certDigestAlgName = json.stringOf('pkcs7.verify.signerInfo[i].cert.digestAlgName');
    contentType = json.stringOf('pkcs7.verify.signerInfo[i].contentType');
    signingTime = json.stringOf('pkcs7.verify.signerInfo[i].signingTime');
    messageDigest = json.stringOf('pkcs7.verify.signerInfo[i].messageDigest');
    signingAlgOid = json.stringOf('pkcs7.verify.signerInfo[i].signingAlgOid');
    signerDigest = json.stringOf('pkcs7.verify.signerInfo[i].signerDigest');
    j = 0;
    countJ = json.sizeOfArray('pkcs7.verify.signerInfo[i].authAttr');
    while (j < countJ) {
      json.j = j;
      oid = json.stringOf('pkcs7.verify.signerInfo[i].authAttr[j].oid');
      oidName = json.stringOf('pkcs7.verify.signerInfo[i].authAttr[j].oidName');
      der = json.stringOf('pkcs7.verify.signerInfo[i].authAttr[j].der');
      j++;
    }

    i++;
  }

  print('Success!');
}