(Android™) Verify a .p7m and get Algorithm Information

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

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

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

    CkCrypt2 crypt = new CkCrypt2();

    String inFile = "qa_data/p7m/brainpoolP256r1.p7m";
    String outFile = "qa_output/something.dat";

    // Verify and extract the signed data.
    boolean success = crypt.VerifyP7M(inFile,outFile);
    if (success == false) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    // Examine details about the signature(s)
    CkJsonObject json = crypt.LastJsonData();
    json.put_EmitCompact(false);
    Log.i(TAG, 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...
    int i;
    int count_i;
    String strVal;
    String certSerialNumber;
    String certIssuerCN;
    String certIssuerDN;
    String certDigestAlgOid;
    String certDigestAlgName;
    String contentType;
    String signingTime;
    String messageDigest;
    String signingAlgOid;
    String signerDigest;
    int j;
    int count_j;
    String oid;
    String oidName;
    String der;

    i = 0;
    count_i = json.SizeOfArray("pkcs7.verify.digestAlgorithms");
    while (i < count_i) {
        json.put_I(i);
        strVal = json.stringOf("pkcs7.verify.digestAlgorithms[i]");
        i = i + 1;
        }

    i = 0;
    count_i = json.SizeOfArray("pkcs7.verify.signerInfo");
    while (i < count_i) {
        json.put_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;
        count_j = json.SizeOfArray("pkcs7.verify.signerInfo[i].authAttr");
        while (j < count_j) {
            json.put_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 = j + 1;
            }

        i = i + 1;
        }

    Log.i(TAG, "Success!");

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}