how to solve flutter CERTIFICATE_VERIFY_FAILED error while performing a POST request?

Question

I am sending a post request in Dart. It is giving a response when I test it on API testing tools such as Postman. But when I run the app. It gives me the following error:-

E/flutter ( 6264): HandshakeException: Handshake error in client (OS Error: E/flutter ( 6264):  CERTIFICATE_VERIFY_FAILED: unable to get local issuer certificate(handshake.cc:363))

Here is my code of the function -

Future getAccessToken(String url) async {

    try {
      http.post('url',
          body: {
            "email": "xyz@xyz.com",
            "password": "1234"
          }).then((response) {
        print("Reponse status : ${response.statusCode}");
        print("Response body : ${response.body}");
        var myresponse = jsonDecode(response.body);
        String token = myresponse["token"];
      });
    } catch (e) {
      print(e.toString());
    }

Here's the full error body:

E/flutter ( 6264): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception: E/flutter ( 6264): HandshakeException: Handshake error in client (OS Error: E/flutter ( 6264):   CERTIFICATE_VERIFY_FAILED: unable to get local issuer certificate(handshake.cc:363)) E/flutter ( 6264): #0      IOClient.send (package:http/src/io_client.dart:33:23) E/flutter ( 6264): <asynchronous suspension> E/flutter ( 6264): #1      BaseClient._sendUnstreamed (package:http/src/base_client.dart:169:38) E/flutter ( 6264): <asynchronous suspension> E/flutter ( 6264): #2     BaseClient.post (package:http/src/base_client.dart:54:7) E/flutter ( 6264): #3      post.<anonymous closure> (package:http/http.dart:70:16) E/flutter ( 6264): #4      _withClient (package:http/http.dart:166:20) E/flutter ( 6264): <asynchronous suspension> E/flutter ( 6264): #5     post (package:http/http.dart:69:5) E/flutter ( 6264): #6     
_MyLoginFormState.getAccessToken (package:chart/main.dart:74:7) E/flutter ( 6264): <asynchronous suspension> E/flutter ( 6264): #7    
_MyLoginFormState.build.<anonymous closure> (package:chart/main.dart:64:29)

well, if it a self signed one, it won't work. Dart does not allow self signed certificates. One solution (a bad one imho) is to allow certificates, even invalid ones, but it removes the core principle of using certificates. — Muldec, Jan 21 '19 at 13:22
define a class import 'dart:io'; import 'package:http/http.dart' as http; import 'package:http/io_client.dart'; class TrustAllCertificates { static http.Client sslClient() { var ioClient = new HttpClient() ..badCertificateCallback = (X509Certificate cert, String host, int port) { return (host.compareTo("domain-name.com") == 0); }; http.Client _client = IOClient(ioClient); return _client; } } — Frank Gue, Jul 29 '21 at 11:31
Response response = await TrustAllCertificates.sslClient().get(Url, headers: headers); — Frank Gue, Jul 29 '21 at 11:32
Response response = await TrustAllCertificates.sslClient().get(Url, body: bodyRequest, headers: headers); — Frank Gue, Jul 29 '21 at 11:33

score 197 · Accepted Answer · edited Oct 04 '21 at 11:44

197

Just for the sake of clarity specially for the newcomers to Flutter/Dart, here is what you need to do in order to enable this option globally in your project:

In your main.dart file, add or import the following class:

 class MyHttpOverrides extends HttpOverrides{
  @override
  HttpClient createHttpClient(SecurityContext? context){
    return super.createHttpClient(context)
      ..badCertificateCallback = (X509Certificate cert, String host, int port)=> true;
  }
}

In your main function, add the following line after function definition:

HttpOverrides.global = MyHttpOverrides();

This comment was very helpful to pass through this matter, and please note that...

This should be used while in development mode, do NOT do this when you want to release to production, the aim of this answer is to make the development a bit easier for you, for production, you need to fix your certificate issue and use it properly, look at the other answers for this as it might be helpful for your case.

edited Oct 04 '21 at 11:44

m123

2,064
9
26

answered Apr 19 '20 at 23:19

Ma'moon Al-Akash

3,119
1
17
16

2

This helped me with a third party lib that does not give access to the http client instance inside. Now it works, thanks – Leandro Hoffmann Apr 30 '20 at 14:10
4

This solution works perfectly. In my case it's the typical scenario: self-signed cert on dev box. – Henry Mar 11 '21 at 12:56
1

This will work, but it's effectively disabling security in BoringSSL. If you have a good reason to do that (self-signed certs on a dev box that aren't technically valid), that's good. But be cautious about shipping code like this to a production environment... – Dan Field May 04 '21 at 22:27
6

Don't forget to use HttpClient `createHttpClient(SecurityContext? context)` (notice the question mark) for null safety – omarwaleed May 31 '21 at 09:35
on which end this issue is generating ? backend or frontend. What are the permanent possible solutions? – Arslan Kaleem Jun 21 '21 at 19:01
4

For null safety users add ? after SecurityContext like `SecurityContext?` – Pratik Butani Jul 01 '21 at 11:04

Smith · Answer 2 · 2021-10-07T13:25:04.403

51

Download cert from https://letsencrypt.org/certs/lets-encrypt-r3.pem
Add this file to assets/ca/ Flutter project root directory
Add assets/ca/ assets directory in pubspec.yaml

Add this code on your app initialization:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  ByteData data = await PlatformAssetBundle().load('assets/ca/lets-encrypt-r3.pem');
  SecurityContext.defaultContext.setTrustedCertificatesBytes(data.buffer.asUint8List());

  runApp(MyApp());
}

It works with the default chain, so no changes are needed on the server. Android < 7.1.1 clients will still have access in a browser context.

edited Oct 07 '21 at 13:25

answered Oct 07 '21 at 13:14

Smith

651
5
4

2

Great +100. Worked like a charm – Black-8 Oct 23 '21 at 11:22
1

This is working perfectly. – Ilham Safeek Nov 28 '21 at 13:06
Should use this solution for new devices. Please refer to the update from letsencrypt: https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/#:~:text=On%20September%2030%202021%2C%20there,accept%20your%20Let's%20Encrypt%20certificate – Victor Kwok Dec 03 '21 at 10:50
Additionally, I could use my `cert.pem` instead of the expired `lets-encrypt-r3.pem`. – ghchoi Dec 08 '21 at 04:51
Where do ByteData, SecurityContext come from? Is there additional packages need to be installed? Tried this and it says ByteData, SecurityContext, PlatformAssetBundle() not defined. – Elmar Jan 22 '22 at 12:30
import 'package:flutter/services.dart'; for PlatformAssetBundle and import 'dart:io'; for SecurityContext – AnonyKnow Feb 04 '22 at 08:33
Don't know how to thank you, you solved the issue without knowing that I'm using lets encrypt :D – Shady Mohamed Sherif Apr 09 '22 at 03:02
you are a magician – prabin maharjan May 10 '22 at 10:54
Is it good for Production Mode? – Adarsh Raj May 22 '22 at 03:29

Hossein Yousefpour · Answer 3 · 2020-03-27T16:49:25.553

45

If you are using Dio library, just do this:

Dio dio = new Dio();
(dio.httpClientAdapter as DefaultHttpClientAdapter).onHttpClientCreate =
    (HttpClient client) {
  client.badCertificateCallback =
      (X509Certificate cert, String host, int port) => true;
  return client;
};

edited Mar 27 '20 at 16:49

answered Mar 27 '20 at 16:29

Hossein Yousefpour

2,205
15
26

1

i got: ``The name 'DefaultHttpClientAdapter' isn't a type, so it can't be used in an 'as' expression.`` – Zorro Mar 04 '21 at 03:21
@Zorro Did you get any solution for this? I am facing the same exception. – Aanal Mehta Mar 09 '21 at 05:52
@aanal-mehta yes look at my post at the bottom. – Zorro Mar 09 '21 at 05:57
@Zorro Can you share the link? – Aanal Mehta Mar 09 '21 at 06:34
@aanal-mehta i mean https://stackoverflow.com/questions/54285172/how-to-solve-flutter-certificate-verify-failed-error-while-performing-a-post-req/60890158?noredirect=1#answer-66468547 – Zorro Mar 09 '21 at 07:01
2

This is a working solution, for anyone who runs into the error @Zorro mentioned, you need to add `package:dio/adapter.dart` to your imports. – Loren.A Feb 21 '22 at 20:31

Adil Maqusood · Answer 4 · 2021-02-26T06:16:13.483

Edit & Update Feb 2021: When this question was earlier asked there were not enough docs and developers to answer. The following answers may be more helpful than this one: Ma'moon Al-Akash Answer, Pedro Massango's Answer & Ken's Answer

If you have not found the solution in these 3 answers, you can try the solution below.

Originally Answered Jan 2019: The correct(but a bad) way to do it ,as I found out, is to allow all certificates.

HttpClient client = new HttpClient();
client.badCertificateCallback = ((X509Certificate cert, String host, int port) => true);

String url ='xyz@xyz.com';

Map map = { 
     "email" : "email" , 
     "password" : "password"
};

HttpClientRequest request = await client.postUrl(Uri.parse(url));

request.headers.set('content-type', 'application/json');

request.add(utf8.encode(json.encode(map)));

HttpClientResponse response = await request.close();

String reply = await response.transform(utf8.decoder).join();

print(reply);

This issue still persists. How would one handle it on production without allowing all certificates? — badrobot15, Oct 10 '21 at 07:11

score 26 · Answer 5 · answered Feb 07 '21 at 18:02

26

This Code work for me

class MyHttpOverrides extends HttpOverrides{
  @override
  HttpClient createHttpClient(SecurityContext context){
    return super.createHttpClient(context)
      ..badCertificateCallback = (X509Certificate cert, String host, int port)=> true;
  }
}

void main(){
  HttpOverrides.global = new MyHttpOverrides();
  runApp(MyApp());
}

I think it will the same for you...

answered Feb 07 '21 at 18:02

Grafritz Design

489
5
7

1

this works on mobile, but not on flutter web – Hairy Ass Oct 24 '21 at 10:50
Thanks for this man! saved my night – Apoorv Pandey Mar 24 '22 at 17:05

Pedro Massango · Answer 6 · 2022-01-13T10:27:49.050

21

The best approach (I think so) is to allow certificate for trusted hosts, so if your API host is "api.my_app" you can allow certificates from this host only:

    HttpClient client = new HttpClient();
    client.badCertificateCallback = ((X509Certificate cert, String host, int port) {
     final isValidHost = host == "api.my_app";

     // Allowing multiple hosts
     // final isValidHost = host == "api.my_app" || host == "my_second_host";
     return isValidHost;
    });

If you have more hosts you can just add a new check there.

edited Jan 13 '22 at 10:27

answered Dec 12 '19 at 11:12

Pedro Massango

3,365
2
23
40

This should be the best answer. Many other answers here are walk-around and not safe. Btw, for socket, how to add badCertificateCallback? – Augie Li Apr 13 '20 at 06:06
what if i have 2 hosts, one with certificate expired and another one with valid certificate and i want to check if certificate has expired so redirect to second one? – ferox147 Feb 18 '21 at 07:41
Unfortunatelly I don't know how to do that. AFAIK the best way to do it is to validate the host or request a new certificate if it is not valid. – Pedro Massango Feb 18 '21 at 19:01

Milad Ahmadi · Answer 7 · 2020-05-14T12:16:34.010

import 'package:http/io_client.dart';
import 'dart:io';
import 'package:http/http.dart';
import 'dart:async';
import 'dart:convert';

    Future getAccessToken(String url) async {
      try {
        final ioc = new HttpClient();
        ioc.badCertificateCallback =
            (X509Certificate cert, String host, int port) => true;
        final http = new IOClient(ioc);
        http.post('url', body: {"email": "xyz@xyz.com", "password": "1234"}).then(
            (response) {
          print("Reponse status : ${response.statusCode}");
          print("Response body : ${response.body}");
          var myresponse = jsonDecode(response.body);
          String token = myresponse["token"];
        });
      } catch (e) {
        print(e.toString());
      }
    }

score 6 · Answer 8 · answered May 26 '21 at 10:00

6

Check the device date and time in device settings. The device date and time is set to previous date.

answered May 26 '21 at 10:00

Trendy

121
1
7

2

One of things you should check first before copying code from other answers. – Kent Jun 01 '21 at 13:27

score 5 · Answer 9 · answered Mar 04 '21 at 04:20

Using Dio package for request on my local server with self signed certificat, i prefer to allow a specific host rather than all domains.

//import 'package:get/get.dart' hide Response;  //<-- if you use get package
import 'package:dio/dio.dart';

void main(){
  HttpOverrides.global = new MyHttpOverrides();
  runApp(MyApp());
}

class MyHttpOverrides extends HttpOverrides{
  @override
  HttpClient createHttpClient(SecurityContext context){
    return super.createHttpClient(context)
      ..badCertificateCallback = ((X509Certificate cert, String host, int port) {
        final isValidHost = ["192.168.1.67"].contains(host); // <-- allow only hosts in array
        return isValidHost;
      });
  }
}

// more example: https://github.com/flutterchina/dio/tree/master/example
void getHttp() async {
  Dio dio = new Dio();
  Response response;
  response = await dio.get("https://192.168.1.67");
  print(response.data);
}

createHttpClient isn't a valid override of 'HttpOverrides.createHttpClient' — Mr. ZeroOne, Oct 08 '21 at 10:11
@Mr.ZeroOne make the context optional to match the parent. So `createHttpClient(SecurityContext? context)`. — Roach, Feb 10 '22 at 01:49

score 4 · Answer 10 · answered Feb 12 '21 at 04:51

4

This issue happened to us as we are not using the fullchain.pem generated using let's encrypt on nginx. Once changed that it fixes this issue.

server {
    listen 443 ssl;

    ssl_certificate /var/www/letsencrypt/fullchain.pem;

For Apache, you might need to configure SSLCertificateChainFile. More discussion about the issue https://github.com/flutter/flutter/issues/50699

answered Feb 12 '21 at 04:51

ken

12,377
6
39
34

1

Guys, this is the solution (and it worked for me with nginx). Don't allow bad certificates! They are, well, bad. You are endangering your users! The system has to be able to check the CA. – Michael Antipin Feb 18 '21 at 11:31

score 4 · Answer 11 · answered May 19 '21 at 19:23

For those who need to ignore certificate errors only for certain calls, you could use the HttpOverrides solution already mentioned by numerous answers.

However, there is no need to use it globally. You can use it only for certain calls that you know experience handshake errors by wrapping the call in HttpOverrides.runWithHttpOverrides().

class IgnoreCertificateErrorOverrides extends HttpOverrides{
  @override
  HttpClient createHttpClient(SecurityContext context){
    return super.createHttpClient(context)
      ..badCertificateCallback = ((X509Certificate cert, String host, int port) {
      return true;
    });
  }
}


Future<void> myNonSecurityCriticalApiCall() async {
  await HttpOverrides.runWithHttpOverrides(() async {
    String url = 'https://api.example.com/non/security/critical/service';
    Response response = await get(url);

    // ... do something with the response ...
  }, IgnoreCertificateErrorOverrides());
}

In my case it is an external API which does have a valid SSL certificate and works in the browser but for some reason won't work in my Flutter app.

Gennadiy Ryabkin · Answer 12 · 2022-04-16T15:25:22.383

4

Well, I figured out that the actual root of the problem was out-of-sync time on my test device...

edited Apr 16 '22 at 15:25

answered Jul 31 '21 at 18:02

Gennadiy Ryabkin

6,619
3
29
38

All i did was to check the date on my test device. It was wrong, Resetting it worked – Donzaala Mar 10 '22 at 22:04

score 4 · Answer 13 · answered Sep 27 '21 at 09:39

This is for http library method. here is what you need to do in order to enable this option globally in your project.

    class MyHttpoverrides extends HttpOverrides{
  @override 
  HttpClient createHttpClient(SecurityContext context){
    return super.createHttpClient(context)
    ..badCertificateCallback = (X509Certificate cert, String host, int port)=>true;
  }
}

//void main() => runApp(MyApp());
void main(){
  HttpOverrides.global=new MyHttpoverrides();
  runApp(MyApp());
}

for more details:https://fluttercorner.com/certificate-verify-failed-unable-to-get-local-issuer-certificate-in-flutter/

John Anderton · Answer 14 · 2021-08-05T00:29:22.377

For everyone landing here with a need to solve the problem and not just bypass it allowing everything.

For me the problem solved on the server side (as it should be) with no change in the code. Everything is valid now. On all the other solutions the problem still exists (eg The Postman runs but it displays a configuration error on the globe next to response status) The configuration is Centos/Apache/LetsEncrypt/Python3.8/Django3.1.5/Mod_wsgi/ but I guess that the solution is valid for most installations of Apache/LetsEncrypt

The steps to resolve are

Locate the line "SSLCACertificateFile" on the Virtual Host you wish to config. For example:

SSLCACertificateFile /etc/httpd/conf/ssl.crt/my_ca.crt

Download https://letsencrypt.org/certs/lets-encrypt-r3-cross-signed.txt At the end of /etc/httpd/conf/ssl.crt/my_ca.crt (after the -----END CERTIFICATE-----) start a new line and paste from lets-encrypt-r3-cross-signed.txt everything bellow -----BEGIN CERTIFICATE----- (including -----BEGIN CERTIFICATE-----)
Save /etc/httpd/conf/ssl.crt/my_ca.crt
Restart Apache httpd

References: https://access.redhat.com/solutions/43575 https://letsencrypt.org/certs

Also you can check the validity of your cert in https://www.digicert.com/help/.

score 3 · Answer 15 · edited Feb 01 '22 at 14:50

3

Actually in my case I fixed it after updating the date and time on my pc. Might help someone I guess

edited Feb 01 '22 at 14:50

Gennadiy Ryabkin

6,619
3
29
38

answered Jul 14 '21 at 04:27

bhupesh shakya

78
8

score 3 · Answer 16 · answered Dec 07 '21 at 09:16

3

For me, it was the problem with the android emulator.

I just created a new android emulator that fixed my problem.

answered Dec 07 '21 at 09:16

Md. Ruhul Amin

51
2

Thanks. The problem for me was that the Android Emulator was set for the wrong time and date. Resetting the time/date manually solved the issue. – Luke Apr 26 '22 at 16:07

score 2 · Answer 17 · answered Sep 05 '19 at 08:42

I specifically needed to use lib/client.dart Client interface for http calls (i.e. http.Client instead of HttpClient) . This was required by ChopperClient (link).

So I could not pass HttpClient from lib/_http/http.dart directly to Chopper. ChopperClient can receive HttpClient in the constructor wrapped in ioclient.IOClient.

HttpClient webHttpClient = new HttpClient();
webHttpClient.badCertificateCallback = ((X509Certificate cert, String host, int port) => true);
dynamic ioClient = new ioclient.IOClient(webHttpClient);
final chopper = ChopperClient(
  baseUrl: "https://example.com",
  client: ioClient,
  services: [
    MfService.create()
  ],
  converter: JsonConverter(),
);
final mfService = MfService.create(chopper);

This way you can temporarily ignore CERTIFICATE_VERIFY_FAILED error in your calls. Remember - that's only for development purposes. Don't use this in production environment!

@kosiara - Bartosz Kosarzycki. I am trying to implement your solution but I think it would be better with the full code. ioclientIOClient(..) and MfService can't see where they are defined. Thanks — Santi, Apr 09 '21 at 17:25

OptimisticSeeEverything · Answer 18 · 2021-01-30T14:35:58.147

Update on January 30, 2021: I know the reason, because nginx is configured with some encryption algorithms that flutter does not support! , The specific need to try.

Use tls 1.3 request URL, no problem.

Example

import 'dart:io';

main() async {
  HttpClient client = new HttpClient();
  // tls 1.2 error
//  var request = await client.getUrl(Uri.parse('https://shop.io.mi-img.com/app/shop/img?id=shop_88f929c5731967cbc8339cfae1f5f0ec.jpeg')); 
  // tls 1.3 normal
  var request = await client.getUrl(Uri.parse('https://ae01.alicdn.com/kf/Ud7cd28ffdf6e475c8dc382380d5d1976o.jpg'));
  var response = await request.close();
  print(response.headers);
  client.close(force: true);
}

score 2 · Answer 19 · answered Mar 22 '21 at 09:56

2

For me, it was because I am using HTTPS and the API uses HTTP so I just changed it to HTTP and it works.

answered Mar 22 '21 at 09:56

Khaled Mahmoud

159
1
5

score 1 · Answer 20 · answered Nov 05 '21 at 18:02

This Solution is finally worked. Thanks to Milad

    final ioc = new HttpClient();
    ioc.badCertificateCallback =
        (X509Certificate cert, String host, int port) => true;
    final http = new IOClient(ioc);
    http.post(); //Your Get or Post Request

score 0 · Answer 21 · answered Jan 17 '22 at 13:08

I fixed the issue by generating the full_chain.crt file.

You might have received the your_domain.crt file and your_domain.ca-bundle file. Now what you have to do is combine the crt file and ca-bundle file to generate the crt file.

cat domain.crt domain.ca-bundle >> your_domain_full_chain.crt

Then you just need to put the your_domain_full_chain.crt file in the nginx and it will start working properly.

score -3 · Answer 22 · answered Mar 28 '22 at 17:01

-3

If you use Android Emulator I've found out that this occurs when there is no internet connection. Check that your emulator has a network connection!

answered Mar 28 '22 at 17:01

F.SO7

583
1
8
23

That has nothing to do with internet connection, it's an issue with https: secure http connection. I tthink the best sol so far is, as suggested in many answers above, is to cretae a badCertificateCallback that bypass certficate verification – Adel Ben Hamadi Mar 29 '22 at 17:48

how to solve flutter CERTIFICATE_VERIFY_FAILED error while performing a POST request?

22 Answers22

Linked

Related