Bad Request response when creating a plan on Cybersource

[WillianFeltri]

Hello,

I'm integrating Cybersource into my project however when testing the request to create a plan I'm getting a Bad Response error like below:

CybersourceHelper.php on line 146:
"""
Erro: Client error: `POST https://apitest.cybersource.com/rbs/v1/plans` resulted in a `400 Bad Request` response:\n
{"response":{"rmsg":"Bad Request"}}\n
"""

I'm using Guzzle client to http requests. Below is code snippet:

public function __construct(SettingsHelper $settingsHelper, string $apiKeySetting, string $secretKeySetting, string $merchantIdSetting, Router $router)
{
    parent::__construct($settingsHelper, $apiKeySetting, $router);
    $this->apiKey = $this->getApiKey();
    $this->secretKey = $this->getSettingValue($secretKeySetting, true);
    $this->merchantId = $this->getSettingValue($merchantIdSetting, true);
    $this->host = 'apitest.cybersource.com';
}

// Function used to generate the digest for the given payload
private function generateDigest($requestPayload)
{
    $utf8EncodedString = utf8_encode($requestPayload);
    $digestEncode = hash("sha256", $utf8EncodedString, true);
    return base64_encode($digestEncode);
}

private function getHttpSignature($resourcePath, $httpMethod, $currentDate, $payload)
{
    $digest = "";

    if($httpMethod == "get")
    {
        $signatureString = "host: " . $this->host . "\ndate: " . $currentDate . "\nrequest-target: " . $httpMethod . " " . $resourcePath . "\nv-c-merchant-id: " . $this->merchantId;
        $headerString = "host date request-target v-c-merchant-id";

    }
    else if($httpMethod == "post")
    {
        //Get digest data
        $digest = $this->generateDigest($payload);

        $signatureString = "host: " . $this->host . "\ndate: " . $currentDate . "\nrequest-target: " . $httpMethod . " " . $resourcePath . "\ndigest: SHA-256=" . $digest . "\nv-c-merchant-id: " . $this->merchantId;
        $headerString = "host date request-target digest v-c-merchant-id";
    }

    $signatureByteString = utf8_encode($signatureString);
    $decodeKey = base64_decode($this->secretKey);
    $signature = base64_encode(hash_hmac("sha256", $signatureByteString, $decodeKey, true));
    $signatureHeader = array(
        'keyid="' . $this->apiKey . '"',
        'algorithm="HmacSHA256"',
        'headers="' . $headerString . '"',
        'signature="' . $signature . '"'
    );

    $signatureToken = "Signature:" . implode(", ", $signatureHeader);

    $host = "Host:" . $this->host;
    $vcMerchant = "v-c-merchant-id:" . $this->merchantId;
    $headers = array(
        $vcMerchant,
        $signatureToken,
        $host,
        'Date:' . $currentDate
    );

    if($httpMethod == "post"){
        $digestArray = array("Digest: SHA-256=" . $digest);
        $headers = array_merge($headers, $digestArray);
    }

    return $headers;
}

public function createPlan($planParams) {
    try {
        $resource = "/rbs/v1/plans/";
        $method = "post";
        $url = "https://" . $this->host . "/rbs/v1/plans";

        $resource = utf8_encode($resource);
        $date = date("D, d M Y G:i:s ") . "GMT";

        $headerParams = [];
        $headers = [];

        $headerParams['Accept'] = 'application/hal+json;charset=utf-8';
        $headerParams['Content-Type'] = 'application/json;charset=utf-8';

        foreach ($headerParams as $key => $val) {
            $headers[] = "$key: $val";
        }

        $authHeaders = $this->getHttpSignature($resource, $method, $date, json_encode($planParams));
        $headerParams = array_merge($headers, $authHeaders);

        $params = [
            'headers' => $headerParams,
            'body' => json_encode($planParams),
        ];
        $client = new Client();
        $response = $client->request($method, $url, $params);
        $contents = $response->getBody()->getContents();
        $planData = json_decode($contents, false);
        return $planData;
    } catch (\GuzzleHttp\Exception\ClientException $e) {
        dump("Error: " . $e->getMessage());
        exit;
    }
}

 The code snippet which calls the create plan function:

$planParams = [
    "planInformation" => [
        "name" => "Gold Plan",
        "description" => "New Gold Plan",
        "billingPeriod" => [
            "length" => "1",
            "unit" => "M"
        ],
        "billingCycles" => [
            "total" => "12"
        ]
    ],
    "orderInformation" => [
        "amountDetails" => [
            "currency" => "USD",
            "billingAmount" => "10",
        ]
    ]
];
$result = $this->checkoutHelper->createPlan($planParams);

Could you please help me with this issue?

Thank you in advance!