Develop Reference

Android, OkHttp, AWS4Signer, aws-api-gateway - "Missing Authentication Token"

i am trying to sign a http request to aws api gateway in android using okhttp. i have more or less used the code in this stackoverflow question stackoverflow question
i use CognitoCachingCredentialsProvider() to get a credentialsProvider object. i then use getCredentials() to get the credentials. i then use the following: credentials.getAWSAccessKeyId(), credentials.getAWSSecretKey() and credentials.getSessionToken() to get the necessary keys and token. i use them in postman and am able to successfully execute the api gateway.
the request fails in android using okhttp, returning a code 403 with the message "Missing Authentication Token".
this is how i prepare the request: i build a DefaultRequest object, setting the endpoint and httpmethod. i then use AWS4Signer to sign the request, passing the credentials object as the signer.sign(defaultRequest, credentials) parameter.
i get a map of headers by calling getHeaders() on the defaultRequest. i create two lists, one called key for the key and one called value for the value. i then loop through the map, loading the keys and corresponding values into the two lists.
i then build my okhttp request as follows:
Request request = new Request.Builder()
.url(my ApiEndPoint)
.addHeader(key.get(0), value.get(0))
.addHeader(key.get(1), value.get(1))
.addHeader(key.get(2), value.get(2))
.addHeader(key.get(3), value.get(3))
.addHeader("Content-Type", "application/x-www-form-urlencoded")
.post(body)
.build();
i notice the following:
in the headers map, key x-amz-security-token has a value ....ending in hKADF87VZ44w9IvZ1gU=
printing out the okhttp request, the key x-amz-security-token has a value .... ending in hKADF87VZ44w9IvZ1gU\u003d
the = is replaced by \u003d, could this be the problem? if so, how to prevent this?
otherwise, any help in solving this problem will be greatly appreciated.
thanks

managed to solve the problem. seems that assigning the headers to the OkHttp request was the problem. so here's my code:
i first get AWSSessionCredentials credentials. then:
AmazonWebServiceRequest amazonWebServiceRequest = new AmazonWebServiceRequest() {
};
String API_GATEWAY_SERVICE_NAME = "execute-api";
com.amazonaws.Request requestAws = new DefaultRequest(amazonWebServiceRequest, API_GATEWAY_SERVICE_NAME);
you can use either the service endpoint:
URI uri = URI.create("https://apigateway.eu-west-1.amazonaws.com");
or your api url (the invoke url for api as per Api Gateway console Stages option (The deployed api)):
String invokeUrl = "https://xxxx.execute-api.eu-west-1.amazonaws.com/yyy/zzzzz";
// using the invoke url
URI uri = URI.create(invokeUrl);
requestAws.setEndpoint(uri);
requestAws.setResourcePath(invokeUrl);
requestAws.setHttpMethod(HttpMethodName.POST);
now sign the request
AWS4Signer signer = new AWS4Signer();
signer.setServiceName(API_GATEWAY_SERVICE_NAME);
signer.setRegionName(Region.getRegion(Regions.EU_WEST_1).getName());
signer.sign(requestAws, credentials);
get the headers
// get map of headers
Map<String, String> headers = requestAws.getHeaders();
// create objects for the headers to add manually in OkHttp request builder
String x_date = null;
String x_token = null;
String authorization = null;
//get and assign values
for (Map.Entry<String, String> entry : headers.entrySet()) {
if (entry.getKey().equals("x-amz-security-token")) {
x_token = entry.getValue();
}
if (entry.getKey().equals("X-Amz-Date")) {
x_date = entry.getValue();
}
if (entry.getKey().equals("Authorization")) {
authorization = entry.getValue();
}
}
build the OkHttp request:
Request request = new Request.Builder()
.url(invokeUrl)
.addHeader("Content-Type", "application/json")
.addHeader("X-Amz-Date", x_date)
.addHeader("x-amz-security-token", x_token)
.addHeader("Authorization", authorization)
.post(body)
.build();
now make your OkHttp call.
hope this is helpful to someone.

How to access cookie and check if it has expired using okhttp3 and PersistentCookieStore?

I am working on an Android app in which a log in post request is made to a webservice. The request returns a cookie which expires in 20 minutes.
Using okhttp3 and this PersistentCookieStore library, I got the cookie to be stored and subsequently added it as request header to access authentication-required get requests (e.g. personal information that are non-public).
The code goes this way,
CookieJar myCookieJar = new PersistentCookieJar(new SetCookieCache(),
new SharedPrefsCookiePersistor(this));
OkHttpClient client = new OkHttpClient.Builder().cookieJar(HttpRequests.cookieJar).build();
I then call a method like this inside an (after I have gone through another log in Async task to get the cookie) Async task to perform a get request that requires authentication,
public static String PostReq(String url, String json) {
RequestBody body = RequestBody.create(JSON, json);
Request request = new Request.Builder()
.url(url)
.addHeader("Cookie", "key=value")
.post(body)
.build();
try (Response response = client.newCall(request).execute()) {
return response.body().string();
}
catch(Exception e){
}
}
The .addHeader("Cookie", "key=value") adds the cookie to the header to tell the webservice that I am authenticated.
Here comes my difficulty. Since the cookie expires after 20 minutes, I would like to be able to access the cookie itself to check for the expiration time and possibly redirect the user to the log in activity by calling the method,
myCookie.expiresAt()
and comparing it to
System.currentTimeMillis()
I tried to look at the PersistentCookieStore codes and found that it uses a SharedPreference with the key "CookiePersistence". I looked inside this file while my emulator was running the app and found it to be empty however.
How would I be able to access this cookie that I have obtained? Much thanks for any advice to be given.

OK, this is old, but I was facing the same problem, and here is how I fixed it.
Hold a reference to your SetCookieCache used to instantiate your CookieJar:
SetCookieCache cookieCache = new SetCookieCache();
CookieJar myCookieJar = new PersistentCookieJar(
cookieCache,
new SharedPrefsCookiePersistor(this)
);
Then use this to find your cookie and check it:
for (Cookie cookie : cookieCache) {
if (cookie.name().equals("cookie_name") && cookie.persistent()) {
//cookie is still good
break;
}
}
Or use cookie.expiresAt() to do your thing.

Android: OkHttp request format and authorising apis

I am using the Dirble Api and I am trying to test it to even get some results back but I think I might be doing it the wrong way. This is how I have been trying:
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url("http://api.dirble.com/v2/songs?token={MY_PROVIDED_ACCESS_TOKEN}")
.build();
try {
Response response = client.newCall(request).execute();
System.out.println("Test " + response.body().string());
} catch (IOException e) {
e.printStackTrace();
}
But I keep getting the error:
{"error":"Unauthorized. Invalid or expired token."}
I assumed that this meant the tokens they provided me are just not functioning. So I generated a new one and same result.
This is there guidelines:
https://dirble.com/api-doc#introduction
I cant see anything I am doing wrong but since I am a novice in http requests, I would like to check there is nothing wrong with how I am doing it before I contact them to say the my access codes aren't working.

Can´t Post JSON to server Express js using OkHttp3 in Android

I'm doing some tests using data to register a new user into my DB sending a json by post. The server returns a static string just for testing. I'm getting the proper response using the console and CURL
curl --data '' http://127.0.0.1:3000/api/user/register
<!DOCTYPE html><html><head><title>Express</title><link rel="stylesheet" href="/stylesheets/style.css"></head><body><h1>Express</h1><p>Welcome to Express</p></body></html>
and even with the POSTMAN extension sending a post request to that same URL I'm getting a proper response as well. But the code below is not getting any response from the server. What's missing?. It's not throwing any error and the json is correct after checking the debugger(it shouldn't matter but just in case anyone wants to know), just a regular string. The debugger fails on this line
Response response = client.newCall(request).execute();
private void createUser(String name, String email, String password){
//create JSON
final String userJson = formatUserAsJSON(name,email,password);
//send JSON
new AsyncTask<Void,Void,String>(){
#Override
protected String doInBackground(Void... voids) {
try {
//1.create client Object
OkHttpClient client = new OkHttpClient();
//2.Define request being sent to server
RequestBody postData=new FormBody.Builder()
.add("json",userJson)
.build();
Request request=new Request.Builder()
.url("http://127.0.0.1:3000/api/user/register")
.post(postData)
.build();
//3.Transport the request and wait for response to process next
Response response = client.newCall(request).execute();
String result = response.body().string();
return result;
} catch (Exception e) {
Log.d("error_connection","couldn't connect to the API");
return null;
}
}
}.execute();
}
I would appreciate some feedback on this problem. Thank you very much
EDIT: The server is not giving any response cause it's not being reached by the android app. I'm seeing in the ubuntu console and nodejs is not printing any message of any request.....
EDIT 2: In the Android manifest I have the user permission to access the network so it's not that.....
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

You are sending your JSON inside a FormBody
try this:
RequestBody postData = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), userJson);

I solved the problem putting the network IP(it also works if you put the Public internet IP, I've tried it) of the server cause 127.0.0.1 was refering to the Genymotion emulator itself, silly me :S. But that was the answer. Thanks everyone for their support.

How to use Etags with Volley

I haven't been able to find a direct answer to this question anywhere, so it's time to finally ask:
Does Volley take care of sending ETags in GET requests?
After researching online, I vaguely think it does, however, I'm not sure. I have an API that uses ETags. In my code, I already account for the cached response:
String url = Uri.parse(Statics.baseURL + "/users/" + Statics.user.getUser_id() + "/items").buildUpon()
.appendQueryParameter("token",Statics.token)
.build().toString();
// Check to see if the response got cached
if(requestQueue.getCache().get(url)!=null){
//response exists
String cachedResponse = new String(requestQueue.getCache().get(url).data);
processItems(cachedResponse);
}
Request request = new JsonRequest(
Request.Method.GET,
url,
null,
null,
new ErrorListener(context)){
#Override
protected Response parseNetworkResponse(NetworkResponse response) {
// Only process the items if the response is modified
if(!response.notModified)
processItems(new String(response.data));
return null;
}
};
requestQueue.add(request);
I would only like to handle the data from the API if the data is modified, but I always get a response code = 200 and notModified = false back.
I am not manually setting the If-None-Match header because I was hoping Volley would keep track of it for me. Is this correct?