<?php
require_once("instagram.php");
$username = 'ТУТ ЛОГИН';
$password = 'ТУТ ПАРОЛЬ';
$agent = 'Instagram 6.21.2 Android (19/4.4.2; 480dpi; 1152x1920; Meizu; MX4; mx4; mt6595; en_US)';
$guid = GenerateGuid();
$device_id = "android-".$guid;
$data ='{"device_id":"'.$device_id.'","guid":"'.$guid.'","username":"'.$username.'","password":"'.$password.'","Content-Type":"application/x-www-form-urlencoded; charset=UTF-8"}';
$sig    =   GenerateSignature($data);
$data   =   'signed_body='.$sig.'.'.urlencode($data).'&ig_sig_key_version=6';
$login  =   SendRequest('accounts/login/', true, $data, $agent, false);
print_r($login);
// Со входомом все ОК


$data = '{"user_id":"'.$user_id.'","device_id":"'.$device_id.'","guid":"'.$guid.'","device_timestamp":"'.time().'","Content-Type":"application/x-www-form-urlencoded; charset=UTF-8"}';
$sig            =   GenerateSignature($data);
$new_data       =   'signed_body='.$sig.'.'.urlencode($data).'&ig_sig_key_version=6';
$follow         =   SendRequest('friendships/create/1417795125', true, $new_data, $agent, true);
print_r($follow);
//А тут выдает
//Array ( [0] => 400 [1] => {"status":"fail","message":"Please update your Instagram app to continue following."} )
?>

<?php
function SendRequest($url, $post, $post_data, $user_agent, $cookies) {

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://i.instagram.com/api/v1/'.$url);
/*
curl_setopt($ch, CURLOPT_PROXY, $proxy);
curl_setopt($ch, CURLOPT_PROXYUSERPWD, $proxyauth);
*/
curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

if($post) {
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
}

if($cookies) {
    curl_setopt($ch, CURLOPT_COOKIEFILE, 'cookies.txt');
} else {
    curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookies.txt');
}

$response = curl_exec($ch);
$http = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
return array($http, $response);
}
function GenerateGuid() {
 return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
        mt_rand(0, 65535),
        mt_rand(0, 65535),
        mt_rand(0, 65535),
        mt_rand(16384, 20479),
        mt_rand(32768, 49151),
        mt_rand(0, 65535),
        mt_rand(0, 65535),
        mt_rand(0, 65535));
}
function GenerateSignature($data) {
 return hash_hmac('sha256', $data, '25eace5393646842f0d0c3fb2ac7d3cfa15c052436ee86b5406a8433f54d24a5');
}
?>