NiftyCloud mobile backend (http://mb.cloud.nifty.com/) REST API用PHPサンプル push通知しかテストしてないです...。 全部POSTで処理してるので、push通知以外の場合は適宜直す必要あります。

API.php

<?php
namespace Nifty\Cloud\mBaaS;

class API
{
	public $settings = [
		'application_key' => null,
		'client_key' => null,
		'api_url' => 'https://mb.api.cloud.nifty.com/2013-09-01/',
		'SignatureMethod' => 'HmacSHA256',
		'SignatureVersion' => 2,
	];

	private $request_params=null;
	private $request_url=null;
	private $response_status=null;
	private $is_error = true;
	
	public function __construct($settings=array())
	{
		$this->settings($settings);
	}

	public function settings($settings=null)
	{
		if ( is_null($settings) )
			return $this->settings ;
		
		$this->settings = array_merge($this->settings, $settings);
		return $this->settings;
	}
	
	public function isError()
	{
		return $this->is_error;
	}

	public function request($method, $body=[], $query=[])
	{
		$this->is_error = true ;
		$this->response_status = null;
		$this->request_params = null;
		$this->request_url = null;
		
		$sign_date = $this->sign_date();

		$this->request_params = array_merge(
			[
				'X-NCMB-Application-Key' => $this->settings['application_key'],
				'SignatureVersion' => $this->settings['SignatureVersion'],
				'SignatureMethod' => $this->settings['SignatureMethod'],
				'X-NCMB-Timestamp' => $sign_date,
			],
			$query
		);
		
		$this->request_url = "{$this->settings['api_url']}{$method}";
		$sign = $this->sign();

		$headers = [
			'Content-type: application/json',
			"X-NCMB-Application-Key: {$this->settings['application_key']}",
			"X-NCMB-Timestamp: {$sign_date}",
			"X-NCMB-Signature: {$sign}"
		];

		$ch = curl_init();
		curl_setopt($ch, CURLOPT_HEADER, true);
		curl_setopt($ch, CURLOPT_URL, $this->request_url);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_HTTPGET, false) ;
		curl_setopt($ch, CURLOPT_POST, true) ;
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

		curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body));

		$response = curl_exec($ch);
		if ( $response === false ) {
			return false ;
		}

		try {
			$this->response_status  = curl_getinfo($ch);
			if ( (int)$this->response_status['http_code']/100 != 2 ) {
				$result = $this->analyze_response($response);
			} else {
				$result = $this->analyze_response($response);			
				$this->is_error = false ;
			}
		} catch (Exception $e) {
			$result = [
				'code' => $e->getCode(),
				'error' => 'Respose parse error.'
			];
		}

		curl_close($ch);

		return $result;
	}
	
	public function getResponseStatus()
	{
		return $this->response_status;
	}
	
	private function analyze_response($response)
	{
		list($response_header, $response_body) = explode("\r\n\r\n", $response, 2);
		$result = json_decode($response_body);
		if (($error = json_last_error()) != JSON_ERROR_NONE) {
			throw new Exception("parse error", $error);
		}

		return $result;
	}
	
	private function create_query_string($params)
	{
		$param_string = "";
		foreach ($params as $key => $value) {
			if ( strlen($param_string) > 0 ) 
				$param_string .= "&";
			$param_string .= $key . '=' . $value;
		}

		return $param_string;
	}

	private function sign()
	{
		$params = $this->request_params;
		uksort($params, 'strnatcmp');

		$url_hash = parse_url($this->request_url);

		$string_to_sign = "POST\n{$url_hash['host']}\n{$url_hash['path']}\n";
		$string_to_sign .= $this->create_query_string($params);

		$method = strtolower(substr($params['SignatureMethod'], 4));
		return base64_encode(hash_hmac($method, $string_to_sign, $this->settings['client_key'], true));
	}

	private function sign_date($time=null)
	{
		return date('Y-m-d\TH:i:s\Z', time($time));
	}
}

push_sample.php

<?php
include_once('API.php');

$params = [
	'application_key' => '[アプリケーションキー]',
	'client_key' => '[クライアントキー]',
];

$content = [
	'immediateDeliveryFlag' => true,
	'target' => ['ios'],
	'badgeIncrementFlag' => true,
	'message' => 'APIテスト'
];

$api = new \Nifty\Cloud\mBaaS\API($params);

$result = $api->request('push', $content);