Conscrypt Provider app, which can be included from other applications (WIP)

public static String getPackageSignature(String targetPackage, Context context) throws PackageManager.NameNotFoundException, CertificateException, NoSuchAlgorithmException {
    Signature sig = context.getPackageManager().getPackageInfo(targetPackage, PackageManager.GET_SIGNATURES).signatures[0];
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    X509Certificate cert = (X509Certificate) cf.generateCertificate(new ByteArrayInputStream(sig.toByteArray()));
    String hexString = null;
    MessageDigest md = MessageDigest.getInstance("SHA1");
    byte[] publicKey = md.digest(cert.getEncoded());
    hexString = byte2HexFormatted(publicKey);
    return hexString;
}

static String byte2HexFormatted(byte[] arr) {
    StringBuilder str = new StringBuilder(arr.length * 2);
    for (int i = 0; i < arr.length; i++) {
        String h = Integer.toHexString(arr[i]);
        int l = h.length();
        if (l == 1) h = "0" + h;
        if (l > 2) h = h.substring(l - 2, l);
        str.append(h.toUpperCase());
        if (i < (arr.length - 1)) str.append(':');
    }
    return str.toString();
}

// You should probably check if com.mendhak.conscryptprovider is installed first. 
// https://stackoverflow.com/q/6758841/974369
// Then:
try {
    //Get signature to compare - either Github or F-Droid versions
    String signature = getPackageSignature("com.mendhak.conscryptprovider", context);
    if (
            signature.equalsIgnoreCase("C7:90:8D:17:33:76:1D:F3:CD:EB:56:67:16:C8:00:B5:AF:C5:57:DB")
            || signature.equalsIgnoreCase("05:F2:E6:59:28:08:89:81:B3:17:FC:9A:6D:BF:E0:4B:0F:A1:3B:4E")
    ) {
        signatureMatch = true;
    }
    else {
        Log.e("com.mendhak.conscryptprovider found, but with an invalid signature. Ignoring.");
        return;
    }

    //https://gist.github.com/ByteHamster/f488f9993eeb6679c2b5f0180615d518
    Context targetContext = context.createPackageContext("com.mendhak.conscryptprovider",
            Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY);
    ClassLoader classLoader = targetContext.getClassLoader();
    Class installClass = classLoader.loadClass("com.mendhak.conscryptprovider.ConscryptProvider");
    Method installMethod = installClass.getMethod("install", new Class[]{});
    installMethod.invoke(null);
    installed = true;
    Log.i("Conscrypt Provider installed");
} catch (Exception e) {
    Log.e("Could not install Conscrypt Provider", e);
}