Dart Requires Chilkat v11.0.0+

P7S - Access Signature Information (date/time, certificate used, etc.)

See more Digital Signatures Examples

Examine a PKCS7 signature (.p7s) and get information about it. Dart

import 'package:chilkat/chilkat.dart';

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

  // First load the .p7s file into a BinData object..
  final bd = CkBinData();
  try {
    bd.loadFile('qa_data/p7s/sample.p7s');
  } on ChilkatException {
    print('Failed to load .p7s file.');
    return;
  }

  final crypt = CkCrypt2();

  // Assuming this is a signature that contains the original data that was signed..
  try {
    crypt.opaqueVerifyBd(bd);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Examine the last JSON data after signature verification..
  final json = CkJsonObject();
  crypt.getLastJsonData(json);

  json.emitCompact = false;
  print(json.emit());

  // Sample output...
  // Go to http://tools.chilkat.io/jsonParse.cshtml
  // and paste the JSON into the online form to generate JSON parsing code.

  // {
  //   "pkcs7": {
  //     "verify": {
  //       "digestAlgorithms": [
  //         "sha256"
  //       ],
  //       "signerInfo": [
  //         {
  //           "cert": {
  //             "serialNumber": "AAC5FC48C0FD8FBB",
  //             "issuerCN": "AC ABCDEF RFB v5",
  //             "issuerDN": "",
  //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
  //             "digestAlgName": "SHA-256"
  //           },
  //           "contentType": "1.2.840.113549.1.7.1",
  //           "signingTime": "180607195054Z",
  //           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
  //           "signingAlgOid": "1.2.840.113549.1.1.11",
  //           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
  //         },
  //         {
  //           "cert": {
  //             "serialNumber": "324FB38ABD59723F",
  //             "issuerCN": "AC ABCDEF RFB v5",
  //             "issuerDN": "",
  //             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
  //             "digestAlgName": "SHA-256"
  //           },
  //           "contentType": "1.2.840.113549.1.7.1",
  //           "signingTime": "180608182517Z",
  //           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
  //           "signingAlgOid": "1.2.840.113549.1.1.11",
  //           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
  //         }
  //       ]
  //     }
  //   }
  // }
  // 

  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 = '';
  final dt = CkDateTime();

  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');

    // The signingTime isin UTCTime format.
    // UTCTime values take the form of either "YYMMDDhhmm[ss]Z" or "YYMMDDhhmm[ss](+|-)hhmm"
    // Starting in Chilkat v9.5.0.77, the SetFromTimestamp method auto-recognizes the UTCTime format and parses it correctly.
    dt.setFromTimestamp(signingTime);
    // To get the signingTime in other date/time formats, look at the online reference documentation for CkDateTime.
    // There are numerous methods such as GetAsDateTime, GetAsIso8601, GetAsUnixTime, GetAsRfc822, etc.

    messageDigest = json.stringOf('pkcs7.verify.signerInfo[i].messageDigest');
    signingAlgOid = json.stringOf('pkcs7.verify.signerInfo[i].signingAlgOid');
    signerDigest = json.stringOf('pkcs7.verify.signerInfo[i].signerDigest');
    i++;
  }

  // println crypt.LastErrorText;
  print('Success.');
}