Data to Amazon Kinesis from PHP without AWS library dependency

AmazonKinesis.php

<?php

/*
   POST / HTTP/1.1
   Host: kinesis.<region>.<domain>
   x-amz-Date: <Date>
   Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=content-type;date;host;user-agent;x-amz-date;x-amz-target;x-amzn-requestid, Signature=<Signature>
   User-Agent: <UserAgentString>
   Content-Type: application/x-amz-json-1.1
   Content-Length: <PayloadSizeBytes>
   Connection: Keep-Alive
   X-Amz-Target: Kinesis_20130901.PutRecord

// PutRecord
{
"StreamName": "exampleStreamName",
"Data": "XzxkYXRhPl8x",
"PartitionKey": "partitionKey"
}

// PutRecords
"Records": [
{
"Data": blob,
"ExplicitHashKey": "string",
"PartitionKey": "string"
}
],
 */


/**
 *
 */

class AmazonKinesis {

	static  $utc_tz;

	/** @var string $access_key */
	private $ACCESS_KEY;
	/** @var string $secret_key */
	private $SECRET_KEY;
	private $REGION = 'eu-west-1';

	public function __construct($access_key, $secret_key, $region = 'eu-west-1') {
		$this->ACCESS_KEY = $access_key;
		$this->SECRET_KEY = $secret_key;

		if(empty($this->ACCESS_KEY) || empty($this->SECRET_KEY)) {
			// throw new InvalidArgumentException('Must define Amazon access key and secret key');
		}

		$this->REGION = $region;
	}

	function kinesis( $streamName, $records ){

		if( !self::$utc_tz )
			self::$utc_tz = new \DateTimeZone( 'UTC' );

		$APIVERSION = '20131202';
		$datestamp  = new \DateTime( "now", self::$utc_tz );
		$longdate   = $datestamp->format( "Ymd\\THis\\Z");
		$shortdate  = $datestamp->format( "Ymd" );


		$out = array();
		foreach($records as $record){
			$arr = array(
					"Data" => base64_encode(json_encode($record)),
					"PartitionKey" => "part",
					);
			array_push($out, $arr);	
		}

		$payload = json_encode(array( "Records" => $records, "StreamName" => $streamName ));

		// print $payload;

		// establish the signing key
		{
			$ksecret    = 'AWS4' . $this->SECRET_KEY;
			$kdate      = hash_hmac( 'sha256', $shortdate, $ksecret, true );
			$kregion    = hash_hmac( 'sha256', $this->REGION, $kdate, true );
			$kservice   = hash_hmac( 'sha256', 'kinesis', $kregion, true );
			$ksigning   = hash_hmac( 'sha256', 'aws4_request', $kservice, true );
		}

		// command parameters
		$params     = array(
				'host'          => 'kinesis.' + $this->REGION + '.amazonaws.com',
				'content-type'  => 'application/x-amz-json-1.1',
				'x-amz-date'    => $longdate,
				'x-amz-target'  => 'Kinesis_'. $APIVERSION . '.PutRecords',
				'content-length' => strlen( $payload ),
				'user-agent'    => 'PHPKinesisLib',
				'connection'    => 'keep-alive',
				);

		$canonical_request  = $this->createCanonicalRequest( $params, $payload );
		$signed_request     = hash( 'sha256', $canonical_request );
		$sign_string        = "AWS4-HMAC-SHA256\n{$longdate}\n$shortdate/" . $this->REGION . "/kinesis/aws4_request\n" . $signed_request;
		$signature          = hash_hmac( 'sha256', $sign_string, $ksigning );

		$params['authorization'] = "AWS4-HMAC-SHA256 Credential=" . $this->ACCESS_KEY . "/$shortdate/" . $this->REGION . "/kinesis/aws4_request, " .
			"SignedHeaders=" . implode( ";", array_keys( $params ) )  . ", " .
			"Signature=$signature";


		/*
		 * Execute Crafted Request
		 */

		$url    = "https://kinesis." . $this->REGION . ".amazonaws.com";
		$ch     = curl_init();

		$curl_headers = array();
		foreach( $params as $p => $k )
			$curl_headers[] = $p . ": " . $k;

		curl_setopt($ch, CURLOPT_URL,$url);
		curl_setopt($ch, CURLOPT_POST,1);
		curl_setopt($ch, CURLOPT_POSTFIELDS, $payload);
		curl_setopt($ch, CURLOPT_HTTPHEADER, $curl_headers);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
		curl_setopt($ch, CURLOPT_TCP_NODELAY, true);
		curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false );
		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false );

		// debug opts
		{
			curl_setopt($ch, CURLOPT_VERBOSE, true);
			$verbose = fopen('php://temp', 'rw+');
			curl_setopt($ch, CURLOPT_STDERR, $verbose);
			$result = curl_exec($ch); // raw result
			rewind($verbose);
			$verboseLog = stream_get_contents($verbose);

		}
		$rescode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
		if ($rescode == '200'){
			return true;
		}else{
			throw new KinesisException("Invalid server response " . $rescode .  $result);
		}
	}

	private function createCanonicalRequest( Array $params, $payload )
	{
		$canonical_request      = array();
		$canonical_request[]    = 'POST';
		$canonical_request[]    = '/';
		$canonical_request[]    = '';

		$can_headers            = array(
				'host' => 'kinesis.' . $this->REGION . '.amazonaws.com'
				);

		foreach( $params as $k => $v )
			$can_headers[ strtolower( $k ) ] = trim( $v );

		uksort( $can_headers, 'strcmp' );

		foreach ( $can_headers as $k => $v )
			$canonical_request[] = $k . ':' . $v;

		$canonical_request[] = '';
		$canonical_request[] = implode( ';', array_keys( $can_headers ) );
		$canonical_request[] = hash( 'sha256', $payload );

		$canonical_request = implode( "\n", $canonical_request );

		return $canonical_request;
	}
}

class KinesisException extends Exception {}