Android NDK get classes.dex

const char *security_check::IntegrityHashSecurityChecker::getBaseApkAbsolutePath() {
    jobject jAppInfoObject = getApplicationInfo();
    jclass jAppInfoClass = env->FindClass("android/content/pm/ApplicationInfo");
    jfieldID jSourceDirField = env->GetFieldID(jAppInfoClass, "sourceDir", "Ljava/lang/String;");
    jstring jSourceDirString = (jstring) env->GetObjectField(jAppInfoObject, jSourceDirField);
    const char *sourceApkPath = env->GetStringUTFChars(jSourceDirString, 0);
    env->ReleaseStringUTFChars(jSourceDirString, sourceApkPath);
    return sourceApkPath;
}

std::string security_check::IntegrityHashSecurityChecker::getCodeIntegrityHash() {
    int err = 0;
    zip *z = zip_open(getBaseApkAbsolutePath(), 0, &err);

    const char *name = "classes.dex";
    struct zip_stat st;
    zip_stat_init(&st);
    zip_stat(z, name, 0, &st);

    char *contents = new char[st.size];

    //Read the compressed file
    zip_file *f = zip_fopen(z, name, 0);
    zip_fread(f, contents, st.size);

    std::ofstream stream;
    stream.open("/sdcard/extr/classes.dex", std::ofstream::out);
    stream.write(contents, st.size);

    LOG(getBaseApkAbsolutePath());

    zip_fclose(f);
    zip_close(z);

    return "";
}