kltz

Zeroth step(There is no certificate.)

Download certification:

openssl s_client -showcerts -connect example.com:443 </dev/null 2>/dev/null|openssl x509 -outform PEM >certfile.pem

Convert PEM to DER:

openssl x509 -outform der -in certfile.pem -out certificate.der

kltz

import android.content.ContentResolver;
import android.content.ContentValues;
import android.os.Bundle;
import android.provider.CallLog;
import android.support.v7.app.AppCompatActivity;

import java.sql.Timestamp;
import java.util.Date;
import java.util.Random;