How to log in to the site (vk.com) using Dart? - authentication

Question

I want to log in to https://vk.com and save cookies to use it again. How can I authenticate???
import 'package:http/http.dart' as http;
import 'dart:async';
Future<void> login() async {
String url = 'https://vk.com';
Map<String, String> body = {'email': 'PHONE_NUMBER', 'pass': 'PASSWORD'};
http.Client client = http.Client();
http.Request request = http.Request('POST', Uri.parse(url));
request.bodyFields = body;
request.headers.addAll({
'User-Agent':
'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36',
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Language': 'ru-ru,ru;q=0.8,en-us;q=0.5,en;q=0.3',
'Accept-Encoding': 'gzip, deflate',
'Connection': 'keep-alive',
'DNT': '1'
});
var future = client.send(request).then((response) {
print('status code: ' + response.statusCode.toString());
return response.stream.bytesToString().then((value) {
return print(value.toString());
});
}).catchError((error) {
return print(error.toString());
});
}
This code returns: status code: 200 FormatException: Missing extension byte (at offset 630)
I need something like requests.session() in Python

Answer 1

Все оказалось проще... Неделя была потрачена не зря)))
Необходимы были библиотеки: dio, dio_cookie_manager, cookie_jar.
Одной из главных и самых глупых ошибок было использование обычного Map вместо FormData для отправки POST запроса.
import 'dart:collection';
import 'package:dio/dio.dart';
import 'package:dio_cookie_manager/dio_cookie_manager.dart';
import 'package:cookie_jar/cookie_jar.dart';
Future login() async {
var dio = Dio();
var cookieJar = CookieJar();
dio.interceptors.add(CookieManager(cookieJar));
dio.options.followRedirects = true;
const String phone = 'PHONE';
const String password = 'PASSWORD';
Map<String, String> headers = HashMap();
headers.addAll({
'User-Agent':
'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36',
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Language': 'ru-ru,ru;q=0.8,en-us;q=0.5,en;q=0.3',
'Accept-Encoding': 'gzip, deflate',
'Connection': 'keep-alive',
'DNT': '1',
});
String url = 'https://vk.com/';
dio.options.headers = headers;
cookieJar.loadForRequest(Uri.parse('https://login.vk.com/'));
Response response = await dio.get(url);
String remixstid = response.headers['set-cookie'].toString();
remixstid = remixstid
.substring(remixstid.indexOf('remixstid') + 'remixstid'.length + 1);
remixstid = remixstid.substring(0, remixstid.indexOf(';'));
String remixlgk = response.headers['set-cookie'].toString();
remixlgk =
remixlgk.substring(remixlgk.indexOf('remixlgk') + 'remixlgk'.length + 1);
remixlgk = remixlgk.substring(0, remixlgk.indexOf(';'));
String remixsid = response.headers['set-cookie'].toString();
remixsid =
remixsid.substring(remixsid.indexOf('remixsid') + 'remixsid'.length + 1);
remixsid = remixsid.substring(0, remixsid.indexOf(';'));
String remixusid = response.headers['set-cookie'].toString();
remixusid = remixusid.substring(remixusid.indexOf('remixusid')+'remixusid'.length+1);
remixusid=remixusid.substring(0,remixusid.indexOf(';'));
String html = response.data;
html = html.substring(html.indexOf('id="quick_login_form"'));
html = html.substring(0, html.indexOf('</form>'));
String start = 'action="', end = '"';
String action = html.substring(html.indexOf(start) + start.length);
html = action.substring(action.indexOf(end) + end.length);
action = action.substring(0, action.indexOf(end));
List<String> parts = html.split('<input type="');
Map<String, String> forms = HashMap();
parts.removeAt(0);
String name, value;
parts.forEach((e) {
if (e.startsWith('hidden')) {
start = 'name="';
end = '"';
name = e.substring(e.indexOf(start) + start.length);
name = name.substring(0, name.indexOf(end));
start = 'value="';
value = e.substring(e.indexOf(start) + start.length);
value = value.substring(0, value.indexOf(end));
forms[name] = value;
} else if (e.contains('name="')) {
start = 'name="';
end = '"';
name = e.substring(e.indexOf(start) + start.length);
name = name.substring(0, name.indexOf(end));
if (name == 'email') {
value = phone;
forms[name] = value;
} else if (name == 'pass') {
value = password;
forms[name] = value;
} else
print('No such constant!');
}
});
forms['to'] = 'bG9naW4/bT0xJmVtYWlsPWFzJnRvPWFXNWtaWGd1Y0dodw--';
var forms2 = FormData.fromMap(forms);
response = await dio.post(
'https://login.vk.com/',
queryParameters: {'act': 'login'},
data: forms2,
options: Options(
followRedirects: true,
validateStatus: (status) {
return status < 500;
},
),
);
List<String> lst = [
'remixbdr=0',
'remixsid=$remixsid',
'remixusid=$remixusid',
'remixstid=$remixstid',
'remixflash=0.0.0',
'remixscreen_width=1920',
'remixscreen_height=1080',
'remixscreen_dpr=1',
'remixscreen_depth=24',
'remixscreen_orient=1',
'remixscreen_winzoom=1',
'remixseenads=0',
'remixlang=0',
'remixlhk=$remixlgk',
];
response.headers.forEach((name, values) {
if (name.contains('remixq')) {
lst.add(name + '=' + values.join());
}
});
dio.options.headers['cookie'] = lst.join('; ');
String location = response.headers['location'].toString();
int length = location.length - 1;
location = location.substring(1, length);
Map<String, String> queryParams = {};
String tmp = location.substring(location.indexOf('?') + 1);
location = location.substring(0, location.indexOf('?'));
List<String> params = tmp.split('&');
params.forEach((element) {
List<String> kv = element.split('=');
queryParams.putIfAbsent(kv[0], () => kv[1]);
});
queryParams['to'] = 'aW5kZXgucGhw';
response = await dio.get(location, queryParameters: queryParams);
print('LOGIN : '+response.data.toString().contains('onLoginDone').toString());
}