Java

Validate a .pkpass Archive

See more Digital Signatures Examples

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. Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    // 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();

    success = zip.OpenZip("qa_data/pkpass/invalid.pkpass");
    if (success == false) {
        System.out.println(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 = new CkZipEntry();
    success = zip.EntryOf("manifest.json",ent);
    if (success == false) {
        System.out.println(zip.lastErrorText());
        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"));
    System.out.println(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));

        success = zip.EntryOf(filename,ent);
        if (success == false) {
            System.out.println(zip.lastErrorText());
            return;
            }

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

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

        i = i+1;
        }

    if (someHashesFailed == true) {
        System.out.println("Some hashes failed.");
        return;
        }

    // Let's verify the signature..
    // First get the signature.
    success = zip.EntryOf("signature",ent);
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

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

    // Show the contents of the signature in base64 encoding.
    System.out.println("Signature:");
    System.out.println(bdSignature.getEncoded("base64_mime"));
    System.out.println("----");

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

    System.out.println("signature verified = " + verified);
  }
}