Description:
------------
I've tried many other ways to calculate this SHA-256. All sources gave me expected result (string(64) "88e0d97d68acf161407af5965ae1e33b1743dbc400af1cc8a2020d47f45ca83e"), except PHP.
Source 1: http://hash.online-convert.com/sha256-generator (online sha256-generator)
Source 2: ruby code: OpenSSL::HMAC.hexdigest('sha256','49a40e1d5c24be8a6e7d566a05d346d0','eyJhbGdvcml0aG0iOiJITUFDLVNIQTI1NiIsImV4cGlyZXMiOjEyNzk4MTgwMDAsIm9hdXRoX3Rva2VuIjoiMTIxMTc2NDk3OTEwMTg5fDIuNlBKWkFNTFozOGcxaUZYMXdraUZwZ19fLjM2MDAuMTI3OTgxODAwMC02MjAzMDc1NDJ8UXd5MHVuZEJ2YVlSYnJWcDBFSkN4eGdVRjQ4LiIsInVzZXJfaWQiOiI2MjAzMDc1NDIifQ')

PHP code example (gave me string(64) "61c9a97bd820052765e1291708352acadb397ea15489bf8be18bd34f775cda1a"):
<?php
var_dump(hash_hmac('sha256','eyJhbGdvcml0aG0iOiJITUFDLVNIQTI1NiIsImV4cGlyZXMiOjEyNzk4MTA4MDAsIm9hdXRoX3Rva2VuIjoiMTIxMTc2NDk3OTEwMTg5fDIuNENNcl9UWV9OVnNKTmpSQlNzOGQ1QV9fLjM2MDAuMTI3OTgxMDgwMC02MjAzMDc1NDJ8eFg5QTBLRzRKbnNHNXZmQ2VaSGJpQmNJeE9vLiIsInVzZXJfaWQiOiI2MjAzMDc1NDIifQ','49a40e1d5c24be8a6e7d566a05d346d0',false));
?>

Test script:
---------------
<?php
var_dump(hash_hmac('sha256','eyJhbGdvcml0aG0iOiJITUFDLVNIQTI1NiIsImV4cGlyZXMiOjEyNzk4MTA4MDAsIm9hdXRoX3Rva2VuIjoiMTIxMTc2NDk3OTEwMTg5fDIuNENNcl9UWV9OVnNKTmpSQlNzOGQ1QV9fLjM2MDAuMTI3OTgxMDgwMC02MjAzMDc1NDJ8eFg5QTBLRzRKbnNHNXZmQ2VaSGJpQmNJeE9vLiIsInVzZXJfaWQiOiI2MjAzMDc1NDIifQ','49a40e1d5c24be8a6e7d566a05d346d0',false));
?>

Expected result:
----------------
string(64) "88e0d97d68acf161407af5965ae1e33b1743dbc400af1cc8a2020d47f45ca83e"

Actual result:
--------------
string(64) "61c9a97bd820052765e1291708352acadb397ea15489bf8be18bd34f775cda1a"