(Android™) Validate a .pkpass Archive

Opens a .pkpass archive (which is just a .zip renamed to .pkpass) and validates the contents. The hashes in the manifest are compared with the computed hash values for each individual file. If all computed hash values match, then the signature is verified.

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

    CkCrypt2 crypt = new CkCrypt2();
    CkZip zip = new CkZip();

    boolean success = zip.OpenZip("qa_data/pkpass/invalid.pkpass");
    if (success == false) {
        Log.i(TAG, zip.lastErrorText());
        return;
        }

    // Get the contents of the manifest.json file, which contains something like this:

    // {
    //   "icon.png" : "0296b01347b3173e98438a003b0e88986340b2d8",
    //   "logo.png" : "25de09e2d3b01ce1fe00c2ca9a90a2be1aaa05cf",
    //   "icon@2x.png" : "5afd9585b08c65fdf105a90c8bd643407cba2787",
    //   "pass.json" : "145ea5a5db784fff485126c77ecf7a1fc2a88ee7",
    //   "strip@2x.png" : "468fa7bc93e6b55342b56fda09bdce7c829d7d46",
    //   "strip.png" : "736d01f84cb73d06e8a9932e43076d68f19461ff"
    // }

    CkZipEntry ent = zip.GetEntryByName("manifest.json");
    if (zip.get_LastMethodSuccess() == false) {
        Log.i(TAG, "manifest.json entry not found.");
        return;
        }

    // Get the exact content of the manifest.json for later signature verification.
    CkBinData bdManifest = new CkBinData();
    success = ent.UnzipToBd(bdManifest);

    CkJsonObject json = new CkJsonObject();
    json.put_EmitCompact(false);
    json.Load(ent.unzipToString(0,"utf-8"));
    Log.i(TAG, json.emit());

    // For each file in the JSON, get the filename and hex hash value.
    crypt.put_EncodingMode("hexlower");
    crypt.put_HashAlgorithm("sha1");

    boolean someHashesFailed = false;
    String filename;
    CkStringBuilder sbHashHex = new CkStringBuilder();
    CkBinData bdFileData = new CkBinData();
    int numMembers = json.get_Size();
    int i = 0;
    while (i < numMembers) {
        filename = json.nameAt(i);
        sbHashHex.Clear();
        sbHashHex.Append(json.stringAt(i));

        ent = zip.GetEntryByName(filename);
        if (zip.get_LastMethodSuccess() == false) {
            Log.i(TAG, filename + " not found in the pkpass file.");
            return;
            }

        // Get the data for this file.
        bdFileData.Clear();
        success = ent.UnzipToBd(bdFileData);

        String computedHashHex = crypt.hashBdENC(bdFileData);
        if (sbHashHex.ContentsEqual(computedHashHex,false) == false) {
            Log.i(TAG, "Computed hash does not match stored hash for " + filename);
            Log.i(TAG, "  computed: " + computedHashHex);
            Log.i(TAG, "  stored:   " + sbHashHex.getAsString());
            someHashesFailed = true;
            }
        else {
            Log.i(TAG, "hash verified for " + filename + "(" + computedHashHex + ")");
            }

        i = i + 1;
        }

    if (someHashesFailed == true) {
        Log.i(TAG, "Some hashes failed.");
        return;
        }

    // Let's verify the signature..
    // First get the signature.
    ent = zip.GetEntryByName("signature");
    if (zip.get_LastMethodSuccess() == false) {
        Log.i(TAG, "signature not found in the pkpass file.");
        return;
        }

    CkBinData bdSignature = new CkBinData();
    success = ent.UnzipToBd(bdSignature);

    // Show the contents of the signature in base64 encoding.
    Log.i(TAG, "Signature:");
    Log.i(TAG, bdSignature.getEncoded("base64_mime"));
    Log.i(TAG, "----");

    // Verify the signature against the manifest.json
    crypt.put_EncodingMode("base64");
    boolean verified = crypt.VerifyBdENC(bdManifest,bdSignature.getEncoded("base64"));
    if (verified == false) {
        Log.i(TAG, crypt.lastErrorText());
        }

    Log.i(TAG, "signature verified = " + String.valueOf(verified));

  }

  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."
  }
}