package com.google.android.vending.licensing;
/*
* Copyright (C) 2012 The Android Open Source Project
* Modifications copyright (C) 2012-2013 Saikoa / Itsana BVBA
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URLEncodedUtils;
import android.content.Context;
import android.content.SharedPreferences;
import android.util.Log;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
/**
* Default policy. All policy decisions are based off of response data received
* from the licensing service. Specifically, the licensing server sends the
* following information: response validity period, error retry period, and
* error retry count.
* <p>
* These values will vary based on the the way the application is configured in
* the Android Market publishing console, such as whether the application is
* marked as free or is within its refund period, as well as how often an
* application is checking with the licensing service.
* <p>
* Developers who need more fine grained control over their application's
* licensing policy should implement a custom Policy.
*/
public class APKExpansionPolicy implements Policy {
private static final String TAG = "APKExpansionPolicy";
private static final String PREFS_FILE = "com.android.vending.licensing.APKExpansionPolicy";
private static final String PREF_LAST_RESPONSE = "lastResponse";
private static final String PREF_VALIDITY_TIMESTAMP = "validityTimestamp";
private static final String PREF_RETRY_UNTIL = "retryUntil";
private static final String PREF_MAX_RETRIES = "maxRetries";
private static final String PREF_RETRY_COUNT = "retryCount";
private static final String DEFAULT_VALIDITY_TIMESTAMP = "0";
private static final String DEFAULT_RETRY_UNTIL = "0";
private static final String DEFAULT_MAX_RETRIES = "0";
private static final String DEFAULT_RETRY_COUNT = "0";
private static final long MILLIS_PER_MINUTE = 60 * 1000;
private long mValidityTimestamp;
private long mRetryUntil;
private long mMaxRetries;
private long mRetryCount;
private long mLastResponseTime = 0;
private int mLastResponse;
private PreferenceObfuscator mPreferences;
private Vector<String> mExpansionURLs = new Vector<String>();
private Vector<String> mExpansionFileNames = new Vector<String>();
private Vector<Long> mExpansionFileSizes = new Vector<Long>();
/**
* The design of the protocol supports n files. Currently the market can
* only deliver two files. To accommodate this, we have these two constants,
* but the order is the only relevant thing here.
*/
public static final int MAIN_FILE_URL_INDEX = 0;
public static final int PATCH_FILE_URL_INDEX = 1;
/**
* @param context The context for the current application
* @param obfuscator An obfuscator to be used with preferences.
*/
public APKExpansionPolicy(Context context, Obfuscator obfuscator) {
// Import old values
SharedPreferences sp = context.getSharedPreferences(PREFS_FILE, Context.MODE_PRIVATE);
mPreferences = new PreferenceObfuscator(sp, obfuscator);
mLastResponse = Integer.parseInt(
mPreferences.getString(PREF_LAST_RESPONSE, Integer.toString(Policy.RETRY)));
mValidityTimestamp = Long.parseLong(mPreferences.getString(PREF_VALIDITY_TIMESTAMP,
DEFAULT_VALIDITY_TIMESTAMP));
mRetryUntil = Long.parseLong(mPreferences.getString(PREF_RETRY_UNTIL, DEFAULT_RETRY_UNTIL));
mMaxRetries = Long.parseLong(mPreferences.getString(PREF_MAX_RETRIES, DEFAULT_MAX_RETRIES));
mRetryCount = Long.parseLong(mPreferences.getString(PREF_RETRY_COUNT, DEFAULT_RETRY_COUNT));
}
/**
* We call this to guarantee that we fetch a fresh policy from the server.
* This is to be used if the URL is invalid.
*/
public void resetPolicy() {
mPreferences.putString(PREF_LAST_RESPONSE, Integer.toString(Policy.RETRY));
setRetryUntil(DEFAULT_RETRY_UNTIL);
setMaxRetries(DEFAULT_MAX_RETRIES);
setRetryCount(Long.parseLong(DEFAULT_RETRY_COUNT));
setValidityTimestamp(DEFAULT_VALIDITY_TIMESTAMP);
mPreferences.commit();
}
/**
* Process a new response from the license server.
* <p>
* This data will be used for computing future policy decisions. The
* following parameters are processed:
* <ul>
* <li>VT: the timestamp that the client should consider the response valid
* until
* <li>GT: the timestamp that the client should ignore retry errors until
* <li>GR: the number of retry errors that the client should ignore
* </ul>
*
* @param response the result from validating the server response
* @param rawData the raw server response data
*/
public void processServerResponse(int response,
com.google.android.vending.licensing.ResponseData rawData) {
// Update retry counter
if (response != Policy.RETRY) {
setRetryCount(0);
} else {
setRetryCount(mRetryCount + 1);
}
if (response == Policy.LICENSED) {
// Update server policy data
Map<String, String> extras = decodeExtras(rawData.extra);
mLastResponse = response;
setValidityTimestamp(Long.toString(System.currentTimeMillis() + MILLIS_PER_MINUTE));
Set<String> keys = extras.keySet();
for (String key : keys) {
if (key.equals("VT")) {
setValidityTimestamp(extras.get(key));
} else if (key.equals("GT")) {
setRetryUntil(extras.get(key));
} else if (key.equals("GR")) {
setMaxRetries(extras.get(key));
} else if (key.startsWith("FILE_URL")) {
int index = Integer.parseInt(key.substring("FILE_URL".length())) - 1;
setExpansionURL(index, extras.get(key));
} else if (key.startsWith("FILE_NAME")) {
int index = Integer.parseInt(key.substring("FILE_NAME".length())) - 1;
setExpansionFileName(index, extras.get(key));
} else if (key.startsWith("FILE_SIZE")) {
int index = Integer.parseInt(key.substring("FILE_SIZE".length())) - 1;
setExpansionFileSize(index, Long.parseLong(extras.get(key)));
}
}
} else if (response == Policy.NOT_LICENSED) {
// Clear out stale policy data
setValidityTimestamp(DEFAULT_VALIDITY_TIMESTAMP);
setRetryUntil(DEFAULT_RETRY_UNTIL);
setMaxRetries(DEFAULT_MAX_RETRIES);
}
setLastResponse(response);
mPreferences.commit();
}
/**
* Set the last license response received from the server and add to
* preferences. You must manually call PreferenceObfuscator.commit() to
* commit these changes to disk.
*
* @param l the response
*/
private void setLastResponse(int l) {
mLastResponseTime = System.currentTimeMillis();
mLastResponse = l;
mPreferences.putString(PREF_LAST_RESPONSE, Integer.toString(l));
}
/**
* Set the current retry count and add to preferences. You must manually
* call PreferenceObfuscator.commit() to commit these changes to disk.
*
* @param c the new retry count
*/
private void setRetryCount(long c) {
mRetryCount = c;
mPreferences.putString(PREF_RETRY_COUNT, Long.toString(c));
}
public long getRetryCount() {
return mRetryCount;
}
/**
* Set the last validity timestamp (VT) received from the server and add to
* preferences. You must manually call PreferenceObfuscator.commit() to
* commit these changes to disk.
*
* @param validityTimestamp the VT string received
*/
private void setValidityTimestamp(String validityTimestamp) {
Long lValidityTimestamp;
try {
lValidityTimestamp = Long.parseLong(validityTimestamp);
} catch (NumberFormatException e) {
// No response or not parseable, expire in one minute.
Log.w(TAG, "License validity timestamp (VT) missing, caching for a minute");
lValidityTimestamp = System.currentTimeMillis() + MILLIS_PER_MINUTE;
validityTimestamp = Long.toString(lValidityTimestamp);
}
mValidityTimestamp = lValidityTimestamp;
mPreferences.putString(PREF_VALIDITY_TIMESTAMP, validityTimestamp);
}
public long getValidityTimestamp() {
return mValidityTimestamp;
}
/**
* Set the retry until timestamp (GT) received from the server and add to
* preferences. You must manually call PreferenceObfuscator.commit() to
* commit these changes to disk.
*
* @param retryUntil the GT string received
*/
private void setRetryUntil(String retryUntil) {
Long lRetryUntil;
try {
lRetryUntil = Long.parseLong(retryUntil);
} catch (NumberFormatException e) {
// No response or not parseable, expire immediately
Log.w(TAG, "License retry timestamp (GT) missing, grace period disabled");
retryUntil = "0";
lRetryUntil = 0l;
}
mRetryUntil = lRetryUntil;
mPreferences.putString(PREF_RETRY_UNTIL, retryUntil);
}
public long getRetryUntil() {
return mRetryUntil;
}
/**
* Set the max retries value (GR) as received from the server and add to
* preferences. You must manually call PreferenceObfuscator.commit() to
* commit these changes to disk.
*
* @param maxRetries the GR string received
*/
private void setMaxRetries(String maxRetries) {
Long lMaxRetries;
try {
lMaxRetries = Long.parseLong(maxRetries);
} catch (NumberFormatException e) {
// No response or not parseable, expire immediately
Log.w(TAG, "Licence retry count (GR) missing, grace period disabled");
maxRetries = "0";
lMaxRetries = 0l;
}
mMaxRetries = lMaxRetries;
mPreferences.putString(PREF_MAX_RETRIES, maxRetries);
}
public long getMaxRetries() {
return mMaxRetries;
}
/**
* Gets the count of expansion URLs. Since expansionURLs are not committed
* to preferences, this will return zero if there has been no LVL fetch
* in the current session.
*
* @return the number of expansion URLs. (0,1,2)
*/
public int getExpansionURLCount() {
return mExpansionURLs.size();
}
/**
* Gets the expansion URL. Since these URLs are not committed to
* preferences, this will always return null if there has not been an LVL
* fetch in the current session.
*
* @param index the index of the URL to fetch. This value will be either
* MAIN_FILE_URL_INDEX or PATCH_FILE_URL_INDEX
* @param URL the URL to set
*/
public String getExpansionURL(int index) {
if (index < mExpansionURLs.size()) {
return mExpansionURLs.elementAt(index);
}
return null;
}
/**
* Sets the expansion URL. Expansion URL's are not committed to preferences,
* but are instead intended to be stored when the license response is
* processed by the front-end.
*
* @param index the index of the expansion URL. This value will be either
* MAIN_FILE_URL_INDEX or PATCH_FILE_URL_INDEX
* @param URL the URL to set
*/
public void setExpansionURL(int index, String URL) {
if (index >= mExpansionURLs.size()) {
mExpansionURLs.setSize(index + 1);
}
mExpansionURLs.set(index, URL);
}
public String getExpansionFileName(int index) {
if (index < mExpansionFileNames.size()) {
return mExpansionFileNames.elementAt(index);
}
return null;
}
public void setExpansionFileName(int index, String name) {
if (index >= mExpansionFileNames.size()) {
mExpansionFileNames.setSize(index + 1);
}
mExpansionFileNames.set(index, name);
}
public long getExpansionFileSize(int index) {
if (index < mExpansionFileSizes.size()) {
return mExpansionFileSizes.elementAt(index);
}
return -1;
}
public void setExpansionFileSize(int index, long size) {
if (index >= mExpansionFileSizes.size()) {
mExpansionFileSizes.setSize(index + 1);
}
mExpansionFileSizes.set(index, size);
}
/**
* {@inheritDoc} This implementation allows access if either:<br>
* <ol>
* <li>a LICENSED response was received within the validity period
* <li>a RETRY response was received in the last minute, and we are under
* the RETRY count or in the RETRY period.
* </ol>
*/
public boolean allowAccess() {
long ts = System.currentTimeMillis();
if (mLastResponse == Policy.LICENSED) {
// Check if the LICENSED response occurred within the validity
// timeout.
if (ts <= mValidityTimestamp) {
// Cached LICENSED response is still valid.
return true;
}
} else if (mLastResponse == Policy.RETRY &&
ts < mLastResponseTime + MILLIS_PER_MINUTE) {
// Only allow access if we are within the retry period or we haven't
// used up our
// max retries.
return (ts <= mRetryUntil || mRetryCount <= mMaxRetries);
}
return false;
}
private Map<String, String> decodeExtras(String extras) {
Map<String, String> results = new HashMap<String, String>();
try {
URI rawExtras = new URI("?" + extras);
List<NameValuePair> extraList = URLEncodedUtils.parse(rawExtras, "UTF-8");
for (NameValuePair item : extraList) {
String name = item.getName();
int i = 0;
while (results.containsKey(name)) {
name = item.getName() + ++i;
}
results.put(name, item.getValue());
}
} catch (URISyntaxException e) {
Log.w(TAG, "Invalid syntax error while decoding extras data from server.");
}
return results;
}
}