Should I use URLEncoder for each URL parametr - android

For each request to server in my android app I need to encode parameters, so my string for URL is looks like
"http://example.com/script.php?param1="+URLEncoder.encode(param1.getText().toString(), "UTF-8")+"param2="+URLEncoder.encode(param2.getText().toString(), "UTF-8")+...."
It works but maybe it is possible to use URLEncoder.encode only one time - like this
URLEncoder.encode("http://example.com/script.php?param1="+param1.getText().toString()+"param2="+param2.getText().toString()+....", "UTF-8")
Would it be ok or there are some cases when it can crash?

URL encoding the whole URL will not work, because it would result in something like
"http%3A%2F%2Fexample.com%2Fscript.php%3Fparam1%3Dasdf%26param2%3Djkl"
i.e. all the special characters in the whole URL would be encoded. You also can not url encode the whole query string, because the = and & characters would be encoded.
You have to encode each parameter value to stop special characters in the parameter interfering with the URL parsing. A helper function may reduce the pain.
String url = "http://example.com/script.php?" + encodeArgs("a", "a + b", "b", "=xxx=");
and something to get you started
public String encodeArgs(String... args) {
final String encoding = "UTF-8";
try {
if (args.length % 2 != 0) {
throw new IllegalArgumentException("number of arguments not even");
}
StringBuffer sb = new StringBuffer();
for (int i = 0; i < args.length; i += 2) {
sb.append(URLEncoder.encode(args[i], encoding));
sb.append("=");
sb.append(URLEncoder.encode(args[i + 1], encoding));
sb.append("&");
}
// delete last &, if any
if (sb.length() > 0) {
sb.deleteCharAt(sb.length() - 1);
}
return sb.toString();
} catch (UnsupportedEncodingException e) {
throw new IllegalArgumentException("unsupported encoding " + encoding, e);
}
}

You should not encode complete URL. Encode only param section or in other words, only parts of it that come from "unreliable sources".
So your 1st attempt "http://example.com/script.php?param1="+URLEncoder.encode(param1.getText().toString(), "UTF-8")+"param2="+URLEncoder.encode(param2.getText().toString(), "UTF-8")+...." is correct, and you should continue with it.
URL encoding in Android and Android: howto parse URL String with spaces to URI object? can be useful for more clarity.

Related

How to secure webservice URL?

I have an android app with web service urls. If anyone decrypts my apk file, the webservice url will become visible.I am using HTTP POST for calling web service.
Anyone can read the code by decompiling the apk file from this site.
My registration page url got hacked and sending bulk request to this url with post data. I was using a API_KEY and send the API_KEY with post data. API_KEY was stored in gradle.properties file.
I did not used
minifyEnabled true
shrinkResources true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'` when its got hacked.
After some search, i know that there is no 100% secure methods to hide url.
My code for registration is :
String link = "http://xxxxxxxxxx.php";
String data = URLEncoder.encode("name", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8");
data += "&" + URLEncoder.encode("phone", "UTF-8") + "=" + URLEncoder.encode(phone, "UTF-8");
data += "&" + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
URL url = new URL(link);
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(data);
wr.flush();
I don't know if it is the correct method to post data to a Url.
How can i secure my source code?
Can i store all my web service url in server?
I am beginner to android. Please help!
I use it this in all android application I developed
gradle.properties
API = http://ec2xxxxx.compute.amazonaws.com
API_KEY = $2c11SoL/NjJ28
create utils.gradle
utils.gradle
class Utils {
static def r = new Random(System.currentTimeMillis())
}
def String toJavaCodeString(String string) {
byte[] b = string.getBytes();
int c = b.length;
StringBuilder sb = new StringBuilder();
sb.append("(new Object() {");
sb.append("int t;");
sb.append("public String toString() {");
sb.append("byte[] buf = new byte[");
sb.append(c);
sb.append("];");
for (int i = 0; i < c; ++i) {
int t = Utils.r.nextInt();
int f = Utils.r.nextInt(24) + 1;
t = (t & ~(0xff << f)) | (b[i] << f);
sb.append("t = ");
sb.append(t);
sb.append(";");
sb.append("buf[");
sb.append(i);
sb.append("] = (byte) (t >>> ");
sb.append(f);
sb.append(");");
}
sb.append("return new String(buf);");
sb.append("}}.toString())");
return sb.toString();}
ext.toJavaCodeString = this.&toJavaCodeString
build.gradle
apply from: "utils.gradle"
android {
defaultConfig {
buildConfigField 'String', 'API', toJavaCodeString(API)
buildConfigField 'String', 'API_KEY', toJavaCodeString(API_KEY)
}}
and access your private url;
public static final String API = BuildConfig.API;
There is no way to protect "secret" information such as URLs embedded in an APK. A determined / motivated hacker can defeat any scheme you care to design ... if he / she has access to a platform where your app is being run.
In order for your app to run, the app running on the user's device needs to be able to decrypt the hidden URL. The user can either intercept the URL in decrypted form in the app's address space, or he / she can reverse engineer the algorithm and decryption key you are using to do the decryption.
Another "attack" is that your app needs to use the URL to make a request. That request can be intercepted on the users device before it is protected by the SSL / TLS channel to your (presumably) HTTPS enabled service.
And on top of that, if you embed a "secret" URL into an app and that secret is compromised and you have to turn off / relocate your server, then you are making problems for all (legitimate, paying, etc) users of your app. They won't be happy campers.
The correct approach is to make your service secure ... and use some kind of authentication mechanism so that hackers need more than just the URL to make requests. Users can / should be issued with individual credentials (e.g. auth keys), and you need to implement a way to invalidate a given users' credentials at the server end.
"URL" stands for Universal Resource Locator. The whole point of a URL is to access some kind of resource, and to do this, you obviously have to tell the network you are connecting to what it is you want to fetch.
Now if you are worried that a hacker can access your source code, then surely he can also hook up Wireshark or Fiddler and simply observe what connections your app is making, and what info you are passing along and receiving back.
Sorry, but I simply can't see any good way around this.
If you're worried about your server/services being hacked or DOS`ed, I think you had better focus on securing them as well as you can, rather than trying to hide them.
I have fixed this in two ways
Encrypted the URL in my code with my private key and on request call i decrypted it again,
public static String encryptIt(String value) {
try {
DESKeySpec keySpec = new DESKeySpec(new byte[]{105, 107, 18, 51, 114, 83, 51, 120, 121});
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey key = keyFactory.generateSecret(keySpec);
byte[] clearText = value.getBytes("UTF8");
// Cipher is not thread safe
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, key);
// Log.d("aa", "Encrypted: " + value + " -> " + encrypedValue);
return Base64.encodeToString(cipher.doFinal(clearText), Base64.DEFAULT);
} catch (Exception e) {
e.printStackTrace();
}
return value;
}
and decript it by using this
public static String decryptIt(String value) {
try {
DESKeySpec keySpec = new DESKeySpec(new byte[]{105, 107, 18, 51, 114, 83, 51, 120, 121});//cryptoPass.getBytes("UTF8"));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey key = keyFactory.generateSecret(keySpec);
byte[] encrypedPwdBytes = Base64.decode(value, Base64.DEFAULT);
// cipher is not thread safe
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] decrypedValueBytes = (cipher.doFinal(encrypedPwdBytes));
// Log.d("aa", "Decrypted: " + value + " -> " + decrypedValue);
return new String(decrypedValueBytes);
} catch (Exception e) {
e.printStackTrace();
}
return value;
}
note in my case that the private key is new byte[]{105, 107, 18, 51, 114, 83, 51, 120, 121} i think it was $ecrEt or something like i forget it.
so if they decompile the APK they wan't be able to find the service link inside you code.
so the base url will be like this public static final String ROOT_API = "aHR0cHSC86LSy9tbS2JpuZW50aWtoYWAbGUJhdC5qbw==";
2- Also you have to add progaurd to your code
BUT, they can smurfing the netweok and find the url if the hacker is advance person, in this case you have to user SSl certificate "https" and make the webserivce POST.
hope you got my point.

URLEncoder: encoding string in android

I am constructing String in my android app and then pass it to URLEncoder.
String searchStr;
// then I get some searchStr from shared preferences
// i check it is correct
searchStr = searchStr + "/page/"+pageNumber+"";
Then I pass that searchStr to URL encoder:
try {
String url_params = URLEncoder.encode(params[0]);
String result = downloadURL("some url/" + url_params);
Log.d("key", url_params); // -> php/page/10
}catch (IOException){
Log.d("key", e.getMessage() );
}
So here i get IOException which shows me this message:
http://some url/php%2Fpage%2F10
If I copy paste it to browser it shows me Not found error with this message:
The requested url someurl/php/page/10 was not found on this server
Also if I change those strange sign %2F into / in browser I am able to get the page. So how can I construct proper string with / instead of %2F sign?
You don't encode the entire URL, only parts of it that come from "unreliable sources".
String query = URLEncoder.encode("apples oranges", "utf-8");
String url = "http://stackoverflow.com/search?q=" + query;

pass two parameters with URL link in android

i have problem with two parameters passing with URL link. Can anyone help me?
private void FillDetails(String _userid,int _sporttype) {
al_TeamName=new ArrayList<String>();
try{
spf=SAXParserFactory.newInstance();
sp=spf.newSAXParser();
xr=sp.getXMLReader();
URL sourceUrl = new URL(
"http://10.0.2.2:2291/acd.asmx/Get_Teams?_userid ="+_userid & "_sporttype="+ _sporttype);
MyHandler mh=new MyHandler();
xr.setContentHandler(mh);
xr.parse(new InputSource(sourceUrl.openStream()));
setListAdapter(new MyAdapter());
}
catch(Exception ex)
{
}
}
when i using this code, i am getting null.If i send single parameter then it works fine.
Is this correct procedure for URL passing two parameters?
Thanks in advance..........
UPDATED ANSWER:
Now you have multiple errors in your URL:
URL sourceUrl = new URL("http://10.0.2.2:2291/acd.asmx/Get_Teams?_userid =" +
_userid & "_sporttype="+ _sporttype);
You still have a space before the first = sign
There's no + between the _userid variable and the rest of the string.
The & sign is outside the second string
It should be something like this:
URL sourceUrl = new URL("http://10.0.2.2:2291/acd.asmx/Get_Teams?_userid="
+ _userid + "&_sporttype=" + _sporttype);
ORIGINAL ANSWER:
You currently have a space instead of a = sign after your first parameter:
?_userid "+_userid
should be
?_userid="+_userid
Solved.
URL sourceUrl = new URL("http://0.0.0.0/acd.asmx/GetList?Value1="+Value1+"&ID="+ID);
"http://10.0.2.2:2291/acd.asmx/Get_Teams?_userid ="+_userid & "_sporttype="+ _sporttype);
You have an & after _userid, which probably does who knows what on _userid. Usually a single & does binary manipulation, so you might be transforming what comes out of _userid. Also, I would recommend URLEncoding your REST tags if you aren't doing that already
I would recommend logging the REST parameters while in development as well to double-check that it's being formed correctly
Update: The & was outside the quote and you needed to use a +
"http://10.0.2.2:2291/acd.asmx/Get_Teams?_userid ="+_userid + "&_sporttype="+ _sporttype);
If you came here because you searched for a version working in Kotlin (like me), you can use this function to build your URL:
import java.net.URL
// Your URL you want to append the query on
val url: String = "http://10.0.2.2:2291/acd.asmx/Get_Teams"
// The parameters you want to pass
val params: Map<String, String> = mapOf(
"_userid" to _user_id
, "_sporttype" to _sporttype
)
// The final build url. Standard encoding for URL is already utf-8
val final_url: URL = URL(
"$url?" // Don't forget the question-mark!
+ params.map {
"${it.key}=${it.value}"
}.joinToString("&")
)

JSONObject text must begin with '{' at character 1 of

I had a PHP API which showed a JSON Array, which I then read into an Android Application.
I since moved servers and the android application broke.
I assumed it was the Authentication and thought I would re-build the Android application (Was my first application and thought a re-write could make things better)
For some reason I am now getting this exception error
I read somewhere that I need to parse JSON_FORCE_OBJECT in the PHP json_encode
json_encode($arrMyData, JSON_FORCE_OBJECT);
But I am running PHP 5.2 (Options parameter came out in PHP 5.3)
My code for you to rip into
private void displayAllStories(){
String line;
int intNumStories = 0;
JSONObject arrAllStories;
LinearLayout storiesLayout = (LinearLayout) findViewById(R.id.lyoutStoriesMain);
storiesLayout.removeAllViewsInLayout();
try {
while((line = this.jsonResult.readLine()) != null){
JSONObject arrStories;
arrStories = new JSONObject(line.trim());
intNumStories = Integer.parseInt(arrStories.optString("NumStories"));
arrAllStories = arrStories.getJSONObject("StoryData");
this.strDebug += "We have "+intNumStories+"\n";
}
} catch (IOException e) {
this.strDebug += "Error (3) "+e.getLocalizedMessage()+"\n";
} catch (JSONException e) {
this.strDebug += "Error (4) "+e.getLocalizedMessage()+"\n";
}
}
And the encoded data from the website
{
"NumStories":1,
"StoryData":{
"Story0":{
"ID":"1020",
"OWERNAME":"Alicia",
"STORYMAIN":"Good evening my son was born with bilateral club feet. When he was a week old we started serial casting once a week for 3 months and then he was placed in braces for the next 6 months for a 23 hour period and then for the next 3 months just durning the night. This last visit the doctor said that he needs to have his tendons lengthened and he will go back into cast. After reading all of these articles I am a little scared on what will be best for him. It sounds like the risk of having the surgery are just as heavily weighed as just keeping him in AFO\\'s till he can make his own decision. I would like all advice whether it be positive or negative. Thank you in advance for your help.",
"STORYBRIEF":"Need reassurance that tendon lengthening is the best decision.",
"ADDEDDATE":"2011-12-12 00:51:16",
"CURRENTSTATUS":"n"
}
}
}
Sorry I should add, the code before this which procudes jsonResult is as follows
try{
URL url = null;
URLConnection urlConn = null;
InputStreamReader jsonIsr = null;
BufferedReader jsonBr = null;
//this.strDebug += "URL is "+this.strURL+"\n";
url = new URL(this.strURL);
urlConn = url.openConnection();
jsonIsr = new InputStreamReader(urlConn.getInputStream());
jsonBr = new BufferedReader(jsonIsr, 8192);
this.jsonResult = jsonBr;
return true;
}catch(MalformedURLException e){
this.strDebug += "JSON Error (1) "+e.getLocalizedMessage()+"\n";
}catch(IOException e){
this.strDebug += "JSON Error (2) "+e.getLocalizedMessage()+"\n";
}
}else{
strDebug = "NO URL Passed to JSON\n";
}
// EDIT 2
For those who asking
The error is as the title says
Error (4) A JSONObject text must being with '{' at character 1 of {"NumStories":1, "StoryData":........
Your code assumes that whole JSON data comes on one line: it iterates with readLine() but creates a new JSON object every time.
You are reading the data line by line and trying to convert each line into a JSON object. That won't work because a single line just contains a fragment of a complete JSON object.
I don't know what type jsonResult has. But you'll probably want to read the whole thing at once.
Your old web application probably produced JSON data without line break so a single line would contain a full JSON object.
i think you read the json file line by line and pass to the json object you should like this way the whole string you have to pass to the json object for parsing than only you getting the json
JSONObject arrStories = new JSONObject(jsonResult);
now get the object like this way
intNumStories = Integer.parseInt(arrStories.getString("NumStories"));
This code is going to break, if object takes more than one line (apparemtly it does). Your choices are:
Collect all the strings into string builder, the parse from this string ( http://developer.android.com/reference/org/json/JSONTokener.html )
Take GSON or my databinding layer ( https://github.com/ko5tik/jsonserializer ) and just parse stream into object.

Android, strings loaded from .txt file are not being escaped

I am loading data from a resource within my own application, and the escape characters I place are not being processed the way I expect them to be. For example, a line in my resource would look like this:
Ellington Human Sciences Building<>EHS<>Human Performance Sciences Building\nNeighbor to Ellington Human Sciences Annex (EHSA)<>292<>482<>73<>25<>Human Sciences
Ellington Human Sciences Annex<>EHSA<>Human Performance Sciences Building\nNeighbor to Ellington Human Sciences Building (EHS)<>340<>464<>28<>20<>Human Sciences
my file reader looks like so:
private synchronized void loadPOIs(Resources resource) throws IOException {
if (mLoaded) return;
InputStream inputStream = resource.openRawResource(R.raw.pois);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
String line;
while((line = reader.readLine()) != null) {
String[] strings = TextUtils.split(line, "<>");
if (strings.length < 7) continue;
POI poi = addPOI(strings[0], strings[1], strings[2], strings[3], strings[4], strings[5], strings[6]);
if (strings.length == 8) {
final int len = strings[7].length();
for (int i = 0; i < len; i++) {
final String prefix = strings[7].substring(0, len - i);
addMatch(prefix, poi);
}
}
}
} finally {
reader.close();
}
mLoaded = true;
}
strings[2] would be the line holding the information about the Point of Interest, and they contain the "\n" character. When I call poi.getInfo() (the getter method of retrieving the info, returns a String) the output allows the "\n" to persist.
any ideas?
You are reading text from a file, and '\n' is just as valid text as any other and does not have any special connotation within a text file. If you want a newline instead, then write a newline in your txt file. It's sure easier than performing scaping over text, and you control the source of the data so there should be no trouble in modifying it.

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