app/bundles/PluginBundle/Helper/oAuthHelper.php

<?php

namespace Mautic\PluginBundle\Helper;

use Mautic\PluginBundle\Integration\UnifiedIntegrationInterface;
use Symfony\Component\HttpFoundation\Request;

/**
 * Portions modified from https://code.google.com/p/simple-php-oauth/.
 */
class oAuthHelper
{
    private $clientId;

    private $clientSecret;

    private $accessToken;

    private $accessTokenSecret;

    private $callback;

    private $settings;

    public function __construct(
        UnifiedIntegrationInterface $integration,
        private ?Request $request = null,
        $settings = []
    ) {
        $clientId                = $integration->getClientIdKey();
        $clientSecret            = $integration->getClientSecretKey();
        $keys                    = $integration->getDecryptedApiKeys();
        $this->clientId          = $keys[$clientId] ?? null;
        $this->clientSecret      = $keys[$clientSecret] ?? null;
        $authToken               = $integration->getAuthTokenKey();
        $this->accessToken       = $keys[$authToken] ?? '';
        $this->accessTokenSecret = $settings['token_secret'] ?? '';
        $this->callback          = $integration->getAuthCallbackUrl();
        $this->settings          = $settings;
    }

    public function getAuthorizationHeader($url, $parameters, $method): array
    {
        // Get standard OAuth headers
        $headers = $this->getOauthHeaders();

        if (!empty($this->settings['include_verifier']) && $this->request && $this->request->query->has('oauth_verifier')) {
            $headers['oauth_verifier'] = $this->request->query->get('oauth_verifier');
        }

        if (!empty($this->settings['query'])) {
            // Include query in the base string if appended
            $parameters = array_merge($parameters, $this->settings['query']);
        }

        if (!empty($this->settings['double_encode_basestring_parameters'])) {
            // Parameters must be encoded before going through buildBaseString
            array_walk($parameters, function (&$val, $key, $oauth): void {
                $val = $oauth->encode($val);
            }, $this);
        }

        $signature = array_merge($headers, $parameters);

        $base_info                  = $this->buildBaseString($url, $method, $signature);
        $composite_key              = $this->getCompositeKey();
        $headers['oauth_signature'] = base64_encode(hash_hmac('sha1', $base_info, $composite_key, true));

        return [$this->buildAuthorizationHeader($headers), 'Expect:'];
    }

    /**
     * Get composite key for OAuth 1 signature signing.
     */
    private function getCompositeKey(): string
    {
        if (strlen($this->accessTokenSecret) > 0) {
            $composite_key = $this->encode($this->clientSecret).'&'.$this->encode($this->accessTokenSecret);
        } else {
            $composite_key = $this->encode($this->clientSecret).'&';
        }

        return $composite_key;
    }

    /**
     * Get OAuth 1.0 Headers.
     */
    private function getOauthHeaders(): array
    {
        $oauth = [
            'oauth_consumer_key'     => $this->clientId,
            'oauth_nonce'            => $this->generateNonce(),
            'oauth_signature_method' => 'HMAC-SHA1',
            'oauth_timestamp'        => time(),
            'oauth_version'          => '1.0',
        ];

        if (empty($this->settings['authorize_session']) && !empty($this->accessToken)) {
            $oauth['oauth_token'] = $this->accessToken;
        } elseif (!empty($this->settings['request_token'])) {
            // OAuth1.a access_token request that requires the retrieved request_token to be appended
            $oauth['oauth_token'] = $this->settings['request_token'];
        }

        if (!empty($this->settings['append_callback']) && !empty($this->callback)) {
            $oauth['oauth_callback'] = urlencode($this->callback);
        }

        return $oauth;
    }

    /**
     * Build base string for OAuth 1 signature signing.
     */
    private function buildBaseString($baseURI, $method, $params): string
    {
        $r = $this->normalizeParameters($params);

        return $method.'&'.$this->encode($baseURI).'&'.$this->encode($r);
    }

    /**
     * Build header for OAuth 1 authorization.
     */
    private function buildAuthorizationHeader($oauth): string
    {
        $r      = 'Authorization: OAuth ';
        $values = $this->normalizeParameters($oauth, true, true);

        return $r.implode(', ', $values);
    }

    /**
     * Normalize parameters.
     *
     * @param bool $encode
     * @param bool $returnarray
     *
     * @return string|array<string,string>
     */
    private function normalizeParameters($parameters, $encode = false, $returnarray = false, $normalized = [], $key = '')
    {
        // Sort by key
        ksort($parameters);

        foreach ($parameters as $k => $v) {
            if (is_array($v)) {
                $normalized = $this->normalizeParameters($v, $encode, true, $normalized, $k);
            } else {
                if ($key) {
                    // Multidimensional array; using foo=baz&foo=bar rather than foo[bar]=baz&foo[baz]=bar as this is
                    // what the server expects when creating the signature
                    $k = $key;
                }
                if ($encode) {
                    $normalized[] = $this->encode($k).'="'.$this->encode($v).'"';
                } else {
                    $normalized[] = $k.'='.$v;
                }
            }
        }

        return $returnarray ? $normalized : implode('&', $normalized);
    }

    /**
     * Returns an encoded string according to the RFC3986.
     */
    public function encode($string): string
    {
        return str_replace('%7E', '~', rawurlencode($string));
    }

    /**
     * OAuth1.0 nonce generator.
     *
     * @param int $bits
     */
    private function generateNonce($bits = 64): string
    {
        $result          = '';
        $accumulatedBits = 0;
        $random          = mt_getrandmax();
        for ($totalBits = 0; 0 != $random; $random >>= 1) {
            ++$totalBits;
        }
        $usableBits = intval($totalBits / 8) * 8;

        while ($accumulatedBits < $bits) {
            $bitsToAdd = min($totalBits - $usableBits, $bits - $accumulatedBits);
            if (0 != $bitsToAdd % 4) {
                // add bits in whole increments of 4
                $bitsToAdd += 4 - $bitsToAdd % 4;
            }

            // isolate leftmost $bits_to_add from mt_rand() result
            $moreBits = mt_rand() & ((1 << $bitsToAdd) - 1);

            // format as hex (this will be safe)
            $format_string = '%0'.($bitsToAdd / 4).'x';
            $result .= sprintf($format_string, $moreBits);
            $accumulatedBits += $bitsToAdd;
        }

        return $result;
    }
}