Aws\S3\S3Client::createPresignedRequest PHP Method

    public function createPresignedRequest(CommandInterface $command, $expires)
    {
        $command = clone $command;
        $command->getHandlerList()->remove('signer');
        /** @var \Aws\Signature\SignatureInterface $signer */
        $signer = call_user_func($this->getSignatureProvider(), $this->getConfig('signature_version'), $this->getConfig('signing_name'), $this->getConfig('signing_region'));
        return $signer->presign(\Aws\serialize($command), $this->getCredentials()->wait(), $expires);
    }

 /**
  * Create a link to a S3 object from a bucket. If expiration is not empty, then it is used to create
  * a signed URL
  *
  * @param  string     $object The object name (full path)
  * @param  string     $bucket The bucket name
  * @param  string|int $expiration The Unix timestamp to expire at or a string that can be evaluated by strtotime
  * @throws InvalidDomainNameException
  * @return string
  */
 public function __invoke($object, $bucket = '', $expiration = '')
 {
     $bucket = trim($bucket ?: $this->getDefaultBucket(), '/');
     if (empty($bucket)) {
         throw new InvalidDomainNameException('An empty bucket name was given');
     }
     if ($expiration) {
         $command = $this->client->getCommand('GetObject', ['Bucket' => $bucket, 'Key' => $object]);
         return $this->client->createPresignedRequest($command, $expiration)->getUri()->__toString();
     } else {
         return $this->client->getObjectUrl($bucket, $object);
     }
 }