RAW Curl Post to AWS Kinesis with PHP

gistfile1.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

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


/**
 *
 */

class AWSK
{

    static  $utc_tz;
    const   ACCESS_KEY = '';
    const   SECRET_KEY = '';

    function kinesis( $payload )
    {

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

        $APIVERSION = '20131104';
        $datestamp  = new \DateTime( "now", self::$utc_tz );
        $longdate   = $datestamp->format( "Ymd\\THis\\Z");
        $shortdate  = $datestamp->format( "Ymd" );

        // establish the signing key
        {
            $ksecret    = 'AWS4' . self::SECRET_KEY;
            $kdate      = hash_hmac( 'sha256', $shortdate, $ksecret, true );
            $kregion    = hash_hmac( 'sha256', 'us-east-1', $kdate, true );
            $kservice   = hash_hmac( 'sha256', 'kinesis', $kregion, true );
            $ksigning   = hash_hmac( 'sha256', 'aws4_request', $kservice, true );
        }

        // command parameters
        $params     = array(
            'host'          => 'kinesis.us-east-1.amazonaws.com',
            'content-type'  => 'application/x-amz-json-1.1',
            'x-amz-date'    => $longdate,
            'x-amz-target'  => 'Kinesis_'. $APIVERSION . '.PutRecord',
            'content-length' => strlen( $payload ),
            'user-agent'    => 'LDP',
            'connection'    => 'keep-alive',
        );

        $canonical_request  = $this->createCanonicalRequest( $params, $payload );
        $signed_request     = hash( 'sha256', $canonical_request );
        $sign_string        = "AWS4-HMAC-SHA256\n{$longdate}\n$shortdate/us-east-1/kinesis/aws4_request\n" . $signed_request;
        $signature          = hash_hmac( 'sha256', $sign_string, $ksigning );

        $params['authorization'] = "AWS4-HMAC-SHA256 Credential=" . self::ACCESS_KEY . "/$shortdate/us-east-1/kinesis/aws4_request, " .
                                   "SignedHeaders=" . implode( ";", array_keys( $params ) )  . ", " .
                                   "Signature=$signature";


        /*
         * Execute Crafted Request
         */

        $url    = "https://kinesis.us-east-1.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);
            echo "Verbose information:\n<pre>", htmlspecialchars($verboseLog), "</pre>\n";
        }

        var_dump( $result );
    }

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

        $can_headers            = array(
          'host' => 'kinesis.us-east-1.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;
    }
}

$a = new AWSK();
$a->kinesis( '{
  "StreamName": "promotion-tracking",
  "Data": "XzxkYXRhPl8x",
  "PartitionKey": "test"
}');

I've adapted this for DyanamoDB but I'm recieveing the following error:
"The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details."

What can I do to fix this?

Thank you very much for this code. I fought the AWS sdk and Guzzle to no avail, but this worked liked a charm still.

Thank you so much.